Whole Number 270, ISSN 0429-8284 FUJI ELECTRIC REVIEW
2020 Vol.66 No. 3 Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society
Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society Vol.66 No.3 2020
Printed on recycled paper Fuji Electric Korea Co., Ltd. Overseas Subsidiaries Sales of power distribution and control equipment, drive control equipment, rotators, high-voltage inverters, electronic control panels, medium- and large-sized Non-consolidated subsidiaries * UPS, and measurement equipment Tel +82-2-780-5011 America URL http://www.fujielectric.co.kr/ Fuji Electric Corp. of America Fuji Electric Co.,Ltd. (Middle East Branch Offi ce) Sales of electrical machinery and equipment, semiconductor devices, drive control Promotion of electrical products for the electrical utilities and the industrial plants equipment, and devices Tel +973-17 564 569 Tel +1-732-560-9410 URL https://americas.fujielectric.com/ Fuji Electric Co., Ltd. (Myanmar Branch Offi ce) Providing research, feasibility studies, Liaison services Reliable Turbine Services LLC Tel +95-1-382714 Repair and maintenance of steam turbines, generators, and peripheral equipment Tel +1-573-468-4045 Representative offi ce of Fujielectric Co., Ltd. (Cambodia) Providing research, feasibility studies, Liaison services Fuji SEMEC Inc. Tel +855-(0)23-964-070 2020 Manufacture and sales of door opening and closing systems Fuji Electric’s Power Generation Business to Realize Tel +1-450-641-4811 ■Equity-method Affi liates Vol.66 No. a Low-Carbon Society Fuji Furukawa E&C (Thailand) Co., Ltd. 3 Asia Design and installation contracting for electric facilities construction Tel +66-2-308-2703 Fuji Electric Asia Pacifi c Pte. Ltd. Since the enactment of the Paris Agreement, an international frame- Sales of electrical distribution and control equipment, drive control equipment, and Europe semiconductor devices work for mitigating climate change, countries around the world have Tel +65-6533-0014 Fuji Electric Europe GmbH been taking measures to accelerate decarbonization. As a result, the mar- URL http://www.sg.fujielectric.com/ Sales of electrical/electronic machinery and components Tel +49-69-6690290 Fuji SMBE Pte. Ltd. URL https://www.fujielectric-europe.com/ ket for renewable energy sources, which do not emit greenhouse gases, Manufacture, sales, and services relating to low-voltage power distribution has been expanding globally. In Japan, in addition to eff orts to achieve board(switchgear, control equipment) Fuji Electric France S.A.S Tel +65-6756-0988 Manufacture and sales of measurement and control devices the energy mix outlined in the Strategic Energy Plan, the government URL http://smbe.fujielectric.com/ Tel +33-4-73-98-26-98 URL https://www.fujielectric.fr/en established the Act of Establishing Energy Supply Resilience in June Fuji Electric (Thailand) Co., Ltd. Sales and engineering of electric substation equipment, control panels, and other Fuji N2telligence GmbH * 2 0 2 0 as an initiative to strengthen and improve the sustainability of electric equipment Sales and engineering of fuel cells and peripheral equipment Tel +66-2-210-0615 Tel +49 (0) 3841 758 4500 electricity supply systems. URL http://www.th.fujielectric.com/en/ China This special issue highlights Fuji Electric’s work toward establish- Fuji Electric Manufacturing (Thailand) Co., Ltd. Manufacture and sales of inverters (LV/MV), power systems (UPS, PCS, switching Fuji Electric (China) Co., Ltd. ing resilient and sustainable electricity supply systems and realizing a power supply systems), electric substation equipment (GIS) and vending machines Sales of locally manufactured or imported products in China, and export of locally Tel +66-2-5292178 low-carbon society by introducing the latest topics and technologies in manufactured products Fuji Tusco Co., Ltd. Tel +86-21-5496-1177 the fi eld of power generation. Manufacture and sales of Power Transformers, Distribution Transformers and Cast URL http://www.fujielectric.com.cn/ Resin Transformers Shanghai Electric Fuji Electric Power Technology Tel +66-2324-0100 (Wuxi) Co., Ltd. URL http://www.ftu.fujielectric.com/ Research and development for, design and manufacture of , and provision of Fuji Electric Vietnam Co.,Ltd. * consulting and services for electric drive products, equipment for industrial Sales of electrical distribution and control equipment and drive control equipment automation control systems, control facilities for wind power generation and Tel +84-24-3935-1593 photovoltaic power generation, uninterruptible power systems, and power electron- URL http://www.vn.fujielectric.com/en/ ics products Tel +86-510-8815-9229 Fuji Furukawa E&C (Vietnam) Co., Ltd. * Engineering and construction of mechanics and electrical works Wuxi Fuji Electric FA Co., Ltd. Tel +84-4-3755-5067 Manufacture and sales of low/high-voltage inverters, temperature controllers, gas analyzers, and UPS Fuji CAC Joint Stock Company Tel +86-510-8815-2088 Provide the Solution for Electrical and Process Control System Tel +84-28-3742-0959 Fuji Electric (Changshu) Co., Ltd. URL www.fujicac.com Manufacture and sales of electromagnetic contactors and thermal relays Tel +86-512-5284-5642 PT. Fuji Electric Indonesia URL http://www.csfe.com.cn/ Sales of inverters, servos, UPS, tools, and other component products Tel +62 21 574-4571 Fuji Electric (Zhuhai) Co., Ltd. URL http://www.id.fujielectric.com/ Manufacture and sales of industrial electric heating devices Tel +86-756-7267-861 P.T. Fuji Metec Semarang URL http://www.fujielectric.com.cn/fez/ Manufacture and sales of vending machines and their parts Tel +62-24-3520435 Fuji Electric (Shenzhen) Co., Ltd. URL http://www.fms.fujielectric.com/ Manufacture and sales of photoconductors, semiconductor devices and currency handling equipment Fuji Electric India Pvt. Ltd. Tel +86-755-2734-2910 Sales of drive control equipment and semiconductor devices URL http://www.szfujielectric.com.cn/ Tel +91-22-4010 4870 URL http://www.fujielectric.co.in Fuji Electric Dalian Co., Ltd. Manufacture of low-voltage circuit breakers Fuji Electric Consul Neowatt Private Limited Tel +86-411-8762-2000 Development, manufacuture, engineering, sales and servicing of UPS, Stabilizers, Active Harmonic Filters and other component products Fuji Electric Motor (Dalian) Co., Ltd. Tel +91-44-4000-4200 Manufacture of industrial motors URL https://www.india.fujielectric.com/ Tel +86-411-8763-6555 Fuji Gemco Private Limited Dailan Fuji Bingshan Vending Machine Co.,Ltd. Cover Photo: Design, manufacture, sales, and engineering for drive control systems Development, manufacture, sales, servicing, overhauling, and installation of Muara Laboh Geothermal Power Plant in Indonesia FUJI ELECTRIC REVIEW vol.66 no.3 2020 Tel +91-129-2274831 vending machines, and related consulting Tel +86-411-8754-5798 (Photo courtesy: PT, SEML) date of issue: September 30, 2020 Fuji Electric Philippines, Inc. Manufacture of semiconductor devices Dalian Fuji Bingshan Smart Control Systems Co., Ltd. Tel +63-2-844-6183 Energy management systems, distribution systems, and related system engineer- editor-in-chief and publisher KONDO Shiro ing Corporate R & D Headquarters Fuji Electric Sales Philippines Inc. Tel +86-411-8796-8340 Sales of energy management systems, process automation systems, factory Fuji Electric Co., Ltd. automation systems, power supply and facility systems, and power generation Fuji Electric (Hangzhou) Software Co., Ltd. Gate City Ohsaki, East Tower, Tel +63-2-541-8321 Development of vending machine-related control software and development of URL https://www.ph.fujielectric.com/ management software 11-2, Osaki 1-chome, Shinagawa-ku, Tel +86-571-8821-1661 Tokyo 141-0032, Japan Fuji Electric (Malaysia) Sdn. Bhd. URL http://www.fujielectric.com.cn/fhs/ Manufacture of magnetic disk and aluminum substrate for magnetic disk https://www.fujielectric.co.jp Tel +60- 4- 403-1111 Fuji Electric FA (Asia) Co., Ltd. URL http://www.fujielectric.com.my/ Sales of electrical distribution and control equipment Tel +852-2311-8282 editorial offi ce Fuji Electric Journal Editorial Offi ce Fuji Electric Sales Malaysia Sdn. Bhd. c/o Fuji Offi ce & Life Service Co., Ltd. Sales of energy management systems, process automation systems, factory Fuji Electric Hong Kong Co., Ltd. 1, Fujimachi, Hino-shi, Tokyo 191-8502, automation systems, power supply and facility systems, and vending machines Sales of semiconductor devices and photoconductors Tel +60 (0) 3 2780 9980 Tel +852-2664-8699 Japan URL https://www.my.fujielectric.com/ URL http://www.hk.fujielectric.com/en/ Fuji Electric Co., Ltd. reserves all rights concerning the republication and publication after translation Fuji Furukawa E&C (Malaysia) Sdn. Bhd. * Hoei Hong Kong Co., Ltd. Sales of electrical/electronic components into other languages of articles appearing herein. Engineering and construction of mechanics and electrical works Tel +60-3-4297-5322 Tel +852-2369-8186 All brand names and product names in this journal might be trademarks or registered trademarks of URL http://www.hoei.com.hk/ their respective companies. Fuji Electric Taiwan Co., Ltd. The original Japanese version of this journal is“FUJI ELECTRIC JOURNAL” vol.93 no.3. Sales of semiconductor devices, electrical distribution and control equipment, and drive control equipment Tel +886-2-2511-1820 Contents Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society
[Preface] Geothermal Energy Development for the Low-Carbon 138 Society KAIEDA, Hideshi
Fuji Electric’s Power Generation Business to Realize 140 a Low-Carbon Society: Current Status and Future Outlook HORIE, Tadao UENO, Yasuo KITANISHI, Hirokazu
Muara Laboh Geothermal Power Plant in Indonesia 147 HATTORI, Yasuyuki
Japan’s Largest Class Storage-Battery Equipped 152 Mega Solar Power Plant SHIIBASHI, Tetsuya NAZUKA, Takehiro SATO, Tomoki
Phosphoric Acid Fuel Cells for the Korean Market 159 KAWAKAMI, Koji HORIUCHI, Yoshimi
First Inland GTCC Thermal Power Plant in Japan: 164 Generator Onsite Manufacturing TANIFUJI, Satoshi NAKAYAMA, Hiroki MIZUMOTO, Takayuki
Online Gas Analysis for Deterioration Diagnosis of Rotating 169 Machinery Stator Winding NAKAYAMA, Akinobu ISHII, Yuichi
Unloading and Handling Technology of the Fuel Assembly in 174 Prototype Fast Breeder Reactor “Monju” KOGA, Kazuhiro
Radioactive Waste Treatment Using the Advanced “SIAL®” 180 Solidification Technology SEKINE, Nobuyuki MIKAMI, Hisashi ONOZAKI, Kimihiro
New Products
“Wiserot” LAN-Connected Diagnostic System for Rotating Machine 184 Vibration
Fe-Products Found in Society 187
FUJI ELECTRIC REVIEW vol.66 no.3 2020 Preface Geothermal Energy Development for the Low-Carbon Society
KAIEDA, Hideshi *
Japan has set a goal of reducing greenhouse gas One solution to these challenges involves the on- (GHG) emissions by 26% by 2030 and 80% by 2050 going technical development of enhanced /engineered compared with FY2013 levels, and is presently pro- geothermal systems (EGS), which artificially recharge moting the intensive use of renewable energies in reservoir water, improve water permeability in the order to facilitate the realization of a low-carbon so- reservoir, and create reservoirs. At the Geysers geo- ciety. Geothermal energy is a renewable energy re- thermal power plants in the United States and the source that is characterized by its stable power output. Larderello Geothermal Power Plant in Italy, urban Based on the 5th Strategic Energy Plan formulated wastewater and condensate water from power gen- in July 2018, it will be necessary to increase the total eration are injected into the reservoirs in which steam installed power capacity in Japan from the current production has declined to restore production lev- level of 550 MW to 1,550 MW by 2030. To meet this els. Likewise, at the Yanaizu-Nishiyama Geothermal challenge, the Japanese government has been sup- Power Plant in Japan, river water is injected into res- porting geothermal development by setting relatively ervoirs on an experimental basis. In Germany and high prices for geothermal power generation under the France, hydraulic fracturing is used to enlarge frac- Feed-in-Tariff (FIT) Scheme for renewable energy and tures in reservoirs to increase water permeability and by easing development regulations in national parks. expand hot water and steam production for power gen- Since the introduction of FIT, more than 70 geothermal eration. In the United States in the early 1990s, reser- power plants have been constructed, including binary voirs were artificially created in hot dry rock (HDR) to geothermal power plants that use hot springs to pro- extract heat of 9 MW. Japan also succeeded in extract- duce an output ranging from a few kilowatts to several ing several hundred to several thousand kilowattes of thousand kilowatts, and the Wasabizawa Geothermal heat from HDR. However, at the time, this technique Power Plant, which began operation in 2019 with an was considered too expensive to put into practical use. output of approximately 46 MW. However, geothermal In the United States, the University of Utah is current- development faces several challenges, such as high ly undertaking a demonstration project to commercial- power generation costs and declined output for existing ize HDR power generation. power plants, and technological development is cur- In Iceland, superheated steam at a temperature of rently underway to solve these issues. 450 °C and a pressure of 14 MPa was produced from Conventionally, geothermal development has in- a well at a depth of 2,100 m in 2009. This shows that volved drilling wells from the surface of the earth into it is possible to generate 30 MW of electricity from a naturally occurring underground reservoirs of steam single well. This achievement has attracted attention and hot water and then generating power from the as a supercritical geothermal resource. Japan has also naturally spewed steam and hot water. Reservoirs identified this technology as one of the promising- in range from a few hundred meters to approximately novative methods to reduce greenhouse gas emissions 3,000 m below the surface of the earth. Therefore, it in the “National Energy and Environment Strategy for is difficult to assess their location and capacity using Technological Innovation” formulated by its Cabinet surface-based surveys. In some cases, the well may not Office. Currently, research and development are being reach the reservoir, or additional wells may be required conducted to resist erosion and corrosion of geothermal due to the depletion of produced steam and hot water, materials due to dissolved components in superheated or scale and corrosion protection may be needed due steam, as well as the characterization of bedrock in su- to dissolved components in the steam and hot water. percritical environments and drilling and heat extrac- These types of challenges lead to increased develop- tion technologies. ment risks and power generation costs. As for ground equipment, new technologies are be- ing put to practical use, such as hybrid power genera- * Executive Research Scientist, the Central Research tion, in which biomass or solar heat is used to heat geo- Institute of Electric Power Industry; PhD (Engineering); thermal steam to improve power generation efficiency, President, the Geothermal Research Society of Japan and combined power generation, in which binary power
138 FUJI ELECTRIC REVIEW vol.66 no.3 2020 generation is performed using the hot water produced der of magnitude. In addition, Fuji Electric delivered during the power generation process. Moreover, a one of the world’s largest power generation facilities technology has been recently developed that circulates (140 MW) to New Zealand. Moreover, Japanese manu- carbon dioxide underground instead of hot water to facturers have delivered approximately 70% of the achieve geothermal power generation. world’s turbines for geothermal power plants. Japan The interior of the earth is extremely hot, with has also been using its technology in this field to con- 99% of it estimated to be above 1,000 °C. There are tribute to geothermal development in developing coun- vast amounts of thermal energy resources stored in the tries. earth. However, we are currently limited to develop- Japan has been blessed with many geothermal re- ment activities in shallow underground areas around sources and the technology to develop them. In addi- volcanoes. This is due to development risks and power tion to power generation, it should be noted that the hot generation costs. Despite this, there are 111 active vol- water used during the geothermal power generation canoes in Japan, and the potential for developing con- process can be reused in regional development, such as ventional geothermal resources is estimated to be the in local heating and cooling, agriculture, and fishery. third largest in the world at 23.74 GW. Taken together It is our hope that geothermal development in coopera- with HDR resources and supercritical geothermal re- tion with local communities will contribute to achiev- sources, the potential is expected to increase by an or- ing a low-carbon society. issue: Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s
Geothermal Energy Development for the Low-Carbon Society 139 Current Future Status an Outlook Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society: Current Status and Future Outlook
HORIE, Tadao * UENO, Yasuo * KITANISHI, Hirokazu *
1. Introduction grow throughout the world at an annual rate of around 1% until around 2040, mainly in non-member Fuji Electric’s corporate philosophy hinges on countries of the Organisation for Economic a mission to contribute to prosperity, encourage Co-operation and Development (OECD). creativity, and seek harmony with the environ- At the same time, the development of renewable ment, while the Company’s management policies energy power sources such as solar power and wind are centered on the notion of contributing to society power is rapidly expanding as a measure to mitigate through its energy and environment businesses. In global warming. line with the management policies, Fuji Electric In addition, various countries are developing has been engaged in the power generation business new policies and measures to attain the common to achieve Japan’s energy mix*1 and make energy goal (temperature rise of 2ºC or less) of the Paris infrastructure more resilient to contribute to the Agreement, which was agreed upon at the 21st realization of a decarbonized society. Furthermore, Conference of the Parties (COP21) to the United in response to changes in the social environment, we Nations Framework Convention on Climate Change have been focusing on the field of renewable energy (UNFCCC) as a “sustainable development scenario.” (geothermal, hydro, biomass*2, solar, and wind en- In Japan, the share of electric power sellers who ergy sources). We are thus working to develop and newly entered the market has been rising since the commercialize the technologies that improve output full deregulation of retail electricity in April 2016 stabilization and the adjustability for demand fluc- and deregulation of gas in April 2017, reaching tuations due to time-of-day and weather, in addition 16.2% as of December 2019. to conventional efforts to improve operation effi- The Feed-in Tariff (FIT) Scheme for renew- ciency and maintainability. able energy was introduced in July 2012 and has This paper will describe the current status and contributed to boosting the share of renewable en- future outlook of Fuji Electric’s efforts to realize a ergy in power generation from 10.8% in FY2011 low-carbon society by introducing our initiatives in to over 16.0% as of FY2017. The scheme was re- the energy field and highlighting some major exam- vised in 2016 in an effort to “maximize the adop- ples of how we are achieving our goal. tion of renewable energy while reducing the bur- den on the nation.” Moreover, the “Act on Special 2. Circumstances Regarding Electric Power Measures Concerning Procurement of Renewable Inside and Outside Japan Energy Sources by Electricity Utilities” will be revised on April 1, 2022, and the name of the act Electricity demand is expected to continue to will be changed to the “Act on Special Measures Concerning Promotion of Use of Renewable Energy * Power Generation Business Group, Fuji Electric Co., Electricity.” The following four points are proposed Ltd. for the revision of the act to promote the use of re-
*1 Energy mix: mal power 56%. This 2018 plan sets a goal of generation produces electricity by using bio- Energy mix refers to the “combination reducing CO2 emissions by 26% from that in mass as a fuel for thermal power generation. of various power generation methods to sup- 2013, in addition to the goal of the combina- Biomass, consists of waste-based materials ply electricity to society as a whole.” The tion of the generation methods (energy mix) and crop-based materials, can be dried or 5th Strategic Energy Plan, decided by the of 2030 decided in 2015. processed into chips or pellets to be used as Cabinet in July 2018, showed a combination fuel. ratio of power generation methods for 2030, *2 Biomass power generation: in which renewable energy occupies 22% to Biomass is an organic resource derived 24%, nuclear power 20% to 22%, and ther- from animals and plants. Biomass power
140 newable energy. (1) In addition to the FIT scheme*3 the FIP scheme*4 will be introduced. (2) Development of systems that make the most of the potential of renewable energy (3) Appropriate disposal of renewable energy pow- er generation equipment (4) Revocation of accreditation due to long-term inactivity
3. Geothermal Power Generation Field
Geothermal power generation, including hot- spring power generation, is starting to be recognized both inside and outside Japan as a stable renewable Fig.1 Panoramic view of the Nga Awa Purua Power energy source that is not affected by weather and Generation Plant other natural conditions. The number of flash cycle power generation*5 and construct additional geothermal power plants. facilities, including large ones, has been increasing In Japan, geothermal power generation has also despite the limited heat sources applicable for this been expanding as a renewable energy source due to generation type. There are many projects where the continuation of the FIT purchase price scheme production wells are being developed, and the num- (Refer to “Muara Laboh Geothermal Power Plant ber of power generation facilities is expected to in Indonesia” on page 147). Moreover, there are increase. Figure 1 shows a panoramic view of the currently many plans and development projects be- Nga Awa Purua Geothermal Power Plant in New ing undertaken that take advantage of government Zealand. It has the world’s largest single unit ca- subsidies for geothermal source exploration and well pacity of 140 MW. This plant is the world’s largest drilling, which involves investment risks. triple-flash*6 geothermal plant. As a market-leading manufacturer in the field Meanwhile, binary cycle power generation*7 can of geothermal power generation, we continue to de- utilize low level*8 heat sources, and it allows the low velop technologies that improve the economical ef- temperature geothermal resources to be utilized for ficiency and operational efficiency of plants and -en
power generation. It is expected that it will eventu- hance the corrosion resistance, scale inhibition, reli- Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s ally surpass flash cycle power generation in terms of ability, and maintainability of equipment. In terms the scale of new installations per year. of after-sales services, as in the field of thermal In countries where geothermal power genera- power generation, we have expanded our service tion is commonly used, such as Indonesia, the bases and service line-up, and are actively proposing Philippines, Mexico, Iceland, Kenya, and New services that help customers operate their plants Zealand, there are ongoing plans to development safely, stably, and economically.
*3 FIT Scheme: tracts only steam using a steam-water sepa- tion well. FIT is an acronym for Feed-in Tariff. rator and directly rotates a steam turbine This scheme aims to expand the use of re- when the steam emitted from the wellhead *7 Binary cycle power generation: newable energy by requiring electric utili- contains a large amount of hot water. A power generation system that uses a ties to purchase power generated from re- heat source such as low-temperature steam newable energy sources such as solar, wind, *6 Triple flash system: or hot water. High pressure steam cre- hydro, geothermal and biomass energy A flash system, which only uses steam ated by transferring geothermal heat to a sources at a price set by the government for after separating the steam and water, con- medium (working fluid) with a low boiling a certain period of time. ventionally has not more than two stages of temperature, such as pentane, rotates the steam-water separators, and this structure turbine. It is suitable for low level (low tem- *4 FIP Scheme: cannot make full use of steam pressure to perature) heat sources that cannot be used FIP is an acronym for Feed-in Pre- deliver high efficiency. Fuji Electric has in flash cycle power generation systems. mium. This scheme aims to allow renew- thus created the triple flash system. As able energy sources to be independent en- the name suggests, this system uses three *8 Low level: ergy sources and widely used by putting a stages to extract a greater volume of steam. A low temperature range that has not premium on the selling price of electricity It is a power generation system that maxi- yet been effectively used. For example, hot generated from these energy sources. mizes the use of the heat of the earth while water at around 100°C, process steam used minimizing waste. The hot water separated in factories, and hot water for waste heat. *5 Flash cycle power generation: by the steam-water separator is returned to A power generation system that ex- the ground through a well called a reinjec-
Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society: Current Status and Future Outlook 141 For flash cycle power generation, two plants are izing a low-carbon society through the widespread under construction in Indonesia and Kenya. For bi- use of renewable energy. Since then, large-scale nary cycle power generation, we have completed two solar power generation (mega solar power genera- 5-MW binary cycle power plants, which are some of tion) has been spreading throughout Japan at a rate the Japan’s largest binary cycle power plants. The faster than initially expected by the government. two plants utilize fluorocarbon substitute and - nor Facilities in operation as of March 2020 have an mal pentane respectively as the working fluid. We output capacity of 40 GW. Moreover, the market for are also working on small-scale binary systems for mega solar power generation is expected to continue the Japanese market. to grow in line with the government’s policy of mak- ing it a mainstream power source. 4. Hydroelectric Power Generation Field However, to achieve this growth, there are some technical issues that need to be resolved. The first In Japan, hydroelectric power has been prefer- issue is grid stabilization. Fuji Electric has been entially developed successively over the past 100 working on the development of a grid stabiliza- years at economically advantageous sites. As a re- tion system for mega solar power generation since sult, new sites are tending to be smaller and more 2016. In particular, this task has involved develop- remote and this creates obstacles in terms of up- ing a technology that mitigates output fluctuations front investment. Furthermore, due to the long lead to 1% or less per minute at interconnection points time from planning to development, these types of in accordance with the requirements of Hokkaido projects are often susceptible to changes in the so- Electric Power Co., Inc. In a subsequent paper, we cial and economic environment. will introduce Japan’s largest-class storage-battery Fuji Electric delivered its first hydro power gen- equipped mega solar power plant. It has a total eration equipment in 1936. Since then, we have output of 59.4 MW AC, consisting of a DC capac- developed, designed, manufactured, and delivered ity of 92.2 MW and lithium-ion battery capacity of all kinds of water turbines, from high-head Pelton 25.3 MWh. The plant has been operating smoothly turbines to low-head valve turbines. In 1997, we since the start of selling electricity under the FIT established Voith Fuji Hydro K.K. as a joint venture Scheme on February 1, 2020 (Refer to “Japan’s with Germany’s Voith GmbH & Co. KG, with whom Largest Class Storage-Battery Equipped Mega Solar we have had a technical partnership since 1938. We Power Plant” on page 152). are utilizing Voith Group’s latest technologies and Another technical issue involves developing a global procurement network to continue to expand system that can suppress grid voltage fluctuation our hydro power business. associated with output fluctuations while also mini- Hydro power is a clean, locally produced energy mizing costs. Fuji Electric has developed a device source with low CO2 emissions. Moreover, it can be that can suppress grid voltage variation to within utilized stably regardless of weather conditions. It a specified value by using the reactive power- com is thereby positioned as a base-load power source pensation function of power conditioning systems laying the foundation of electricity supply. (PCSs) without the need of a static var compensator As a measure to support the expansion of re- (SVC). newable energy, FIT has continued to successfully Based on our achievements in Japan, we are provide the industry a boost. In addition to the de- also strengthening our efforts to realize a low- velopment of new small- and medium-scale hydro carbon society on a global level. Specifically, power facilities, projects to renew power plants that Southeast Asia is expected to continue to experience were built during Japan’s hydro power development significant economic growth, which means that- de period 50 to 60 years ago are now thriving unprec- mand for electricity will continue to increase. Since edentedly throughout the country. the region has abundant solar radiation, there are By utilizing three-dimensional flow analysis also high expectations for mega solar power genera- technology to best fit each power plant, the plants tion as a renewable energy. However, regardless of have increased a power output and even an annual the country, grid lines are still developing. As a re- power generation significantly. We will continue sult, technologies for peak-cut functions and fluctua- contributing to reducing environmental burdens by tion mitigation are essential. offering environmentally friendly oil-free technolo- By targeting this market, Fuji Electric has gies that do not use oil pressure and next-generation developed a new 2,500-kVA, 1,500-V-DC large- hydro power equipment that has higher maintain- capacity PCS. It can increase the overload ratio*9 to ability and a longer service life. 200%, allowing mega solar power plants to raise the power output. Leveraging this product, we received 5. Solar Power Generation Field the orders for two projects for storage-battery equipped mega solar power plants with a capacity of FIT was adopted in 2012 with the aim of real- 5 MW apiece located in economic zones in Southeast
142 FUJI ELECTRIC REVIEW vol.66 no.3 2020 Asia and started the construction as an engineering, power plants must be equipped with storage batter- procurement and construction (EPC) contractor. ies or other equipment to reduce output fluctuations Fuji Electric aims to achieve a Low-Carbon to a level that does not affect the frequency adjust- Society from a global perspective. We will thus ment of the power grid. continue to contribute to the spread of mega solar Fuji Electric has a proven track record of deliv- power generation that will serve as a low-cost and ering fluctuation mitigation systems for solar power stable power source. To achieve this, we are taking plants in this region and has the technical ability into account the characteristics of each country and and system line-up capable of meeting the stipu- region while utilizing storage battery control tech- lated requirements. We are also developing a new nology and equipment suited to grid limitations. type of PCS for storage battery equipped systems (PVI1400CJ-3/2600, 1,400 V DC, 2,600 kVA) that 6. Wind Power Generation Field can greatly contribute to system optimization, re- ducing the total cost of operating plants. We plan to Decarbonization in the United States and release this product to the market in FY2021. Europe is mainly led by mega solar and wind power Furthermore, in consideration of the future generation, especially offshore wind power. In spread of offshore wind power plants, 275-kV sub- Japan, wind power generation is also supported station equipment needs to be developed and the by the FIT since it is viewed as an important field measures for voltage fluctuation and harmonic reso- of renewable energy. In December 2018, the “Act nance, which are required for long-distance power on Promoting the Utilization of Sea Areas for the transmission, need to be taken. We also need to Development of Marine Renewable Energy Power meet the various requirements of individual custom- Generation Facilities” was promulgated to promote ers. In order to meet these challenges and the needs large-scale wind power generation. The demand is of customers, we have also amassed technologies for thereby expected to increase over the long term. simulation and the countermeasures against the ef- Specifically, there have traditionally been strin- fects of stray capacitance of cables. gent restrictions on the onshore and offshore instal- lation of equipment in the Hokkaido and Tohoku 7. Fuel Cell Field regions due to grid limitations. However, taking above-mentioned measures has accelerated devel- The use of hydrogen is one way to contribute opment in those regions, resulting in a number of to the realization of a low-carbon society. In recent projects being set in motion. Fuji Electric has been years, fuel cells, typical equipment running on hy-
undertaking EPC projects for wind power plants drogen, have been rapidly increasing in use for a Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s of several tens of megawatts by leveraging our es- variety of applications, such as household fuel cell tablished plant engineering capabilities and equip- cogeneration*10 systems (ENE-FARM*), fuel cell ve- ment, such as that for grid connection and power hicles (FCVs), indoor forklifts, mobile base station stabilization. emergency power sources, and power generation Hokkaido and Tohoku are regions well suited projects in Europe, the United States, and South for wind power generation. However, the capacity Korea. of their power grids is relatively small and measures To produce the fuel for the generation, a hy- need to be taken to ensure power quality by miti- drogen production method that uses a chemical gating output fluctuations due to changes in wind reaction called steam reforming is used. This has conditions. In this regard, Hokkaido Electric Power enabled the use of city gas, LPG, and biogas such Co., Inc. announced its “Technical Requirements for the Output Fluctuation Mitigation Measures of * ENE-FARM is a trademark or registered trademark of Wind Power Generation Facilities” in FY2016. The Tokyo Gas Co., Ltd., Osaka Gas Co., Ltd., and ENEOS requirements state that newly constructed wind Corporation.
*9 Overload ratio: capacity of solar panels compared with the as combined heat and power. It is a highly The amount of electricity generated rated one, which is generally between 120% efficient system that makes effective use of by solar power facilities decreases when the and 170%. The larger this value is, the energy by supplying heat while simultane- sunlight grows dim. Thus, surplus solar faster the return on investment will be. In ously generating electricity. Fuel cells pos- panels are typically installed to complement this respect, the Ministry of Economy, Trade sess excellent characteristics in this regard. the decrease. When connecting power gen- and Industry also states on its website that Phosphoric acid types have a power genera- eration facilities to a power company’s grid, “overloading is not prohibited because it has tion efficiency of 42% and an exhaust heat an appropriate PCS is selected through the some merits.” efficiency of 49%, meaning that the energy grid connection consultation to determine utilization efficiency can be increased up to the capacity. The overload ratio indicates *10 Cogeneration: 91%. that how much bigger the actual installed Cogeneration is commonly referred to
Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society: Current Status and Future Outlook 143 as sewage digester gas. In the future when the ap- hours (15 years), demonstrating the fuel cells’ high plication of hydrogen in society is more widespread, durability and reliability. there will be more opportunities to utilize hydrogen Fuji Electric is committed to making its PAFCs directly. easier to install, more functional, more versatile and Since fuel cells generate power through electro- less expensive, working towards a low-carbon soci- chemical reactions without burning fuel, they do not ety. We are promoting the adoption of fuel cells in depend on the size of power generation equipment countries such as Germany and South Korea, where and can achieve high power generation efficiency initiatives have been enacted to promote the spread even at low output power. Without burning, fuel of fuel cells. In addition, we are developing a model cells emit almost no air pollutants and have low that uses digestion gas, which is supported by the noise and vibration. In addition, by utilizing the FIT as renewable energy source in Japan. As men- heat discharged during power generation, they can tioned above, we are expecting the use of hydrogen provide a high overall efficiency of 90%. to become more widespread in the future. In prepa- As shown in Table 1, fuel cells are classified by ration for this, we are developing hydrogen-fuel- the electrolyte as follows: hosphoric acid fuel cells dedicated PAFCs that are optimized for processes (PAFC), polymer electrolyte fuel cells (PEFC), mol- for directly using hydrogen as fuel to save space and ten carbonate fuel cells (MCFC), and solid oxide fuel costs, contributing to achieve a low-carbon society cells (SOFC). These types have respective operating (Refer to “Phosphoric Acid Fuel Cells for the Korean temperatures and power generation efficiencies, and Market” on page 159). suitable applications. Fuji Electric recognized the potential for PAFCs 8. Thermal Power Generation Field and started developing them in 1973 because of their exhaust heat temperature and electrolyte sta- As the world moves toward a low-carbon energy bility. In cooperation with the Japanese govern- supply, COP21 and other international conferences ment, gas companies and power companies, we have have established CO2 reduction targets. The num- examined field tests for more than 90 units having ber of fossil fuel power generation facilities tend to various capacities ranging from 50 kW to 5 MW. In decline. 1998, we began selling 100-kW commercial units In Japan, a policy was announced in July 2020 that incorporated our experiences and expertise. As to reduce the use of coal-fired power plants. In line of March 2020, we have shipped a total of 100 units with this policy, specific studies are now being- un worldwide, of which 82 units are currently in opera- dertaken on new regulatory measures to fade out tion. Among these units, 33 of them were shipped inefficient coal-fired power plants in the future. overseas to Germany, South Korea and other coun- However, the current high level of dependence tries, and 32 units use digester gas, a renewable on fossil fuels and the need for a stable energy sup- energy source, as fuel. Fuji Electric’s fuel cell power ply mean that fossil fuel power generation is ex- generation equipment has a track record of very pected to decrease but not entirely disappear. In or- long cumulative operating times of up to 130,000 der to maintain the stability of power grids even af- ter the share of renewable energy increases, the de- Table 1 Types of fuel cells, power generation efficiency, and mand for gas turbine combined cycle (GTCC) power applications generation is expected to continue to increase due to Phosphoric Polymer elec- Molten car- Solid oxide the high efficiency and low environmental impact. Type acid type trolyte type bonate type type (PAFC) (PEFC) (MCFC) (SOFC) It is against this backdrop that Fuji Electric is working to improve the efficiency of thermal power Operating 190 °C to 600 °C to 700 °C to tempera- 70 °C to 90 °C generation to increase economical efficiency and re- 200 °C 700 °C 1,000 °C ture duce environmental burdens, thereby contributing Power to the creation of customer value throughout the genera- 40% to 45% 35% to 40% 45% to 50% 45% to 60% life cycle of the facilities. Specifically, we provide tion ef- ficiency secure, highly reliable technologies, such as high temperature and high pressure steam equipment, Household Main use Business use 11 applica- Business use Business use reheat cycles* for small- and medium-capacity tur- Automobile Household use tions use bines, compact steam turbines, fewer turbine cas- ings.
*11 Reheat cycle: superheated, and then sends it back to the increase the turbine output per steam flow The reheat cycle extracts some of the turbine to expand it to the final pressure. rate. steam in the expansion process of the tur- Using reheat cycle can achieve better bine, sends it to the boiler to reheat it to be thermal efficiency than the normal cycle and
144 FUJI ELECTRIC REVIEW vol.66 no.3 2020 By making use of these cultivated technologies (As of January 18, 2021) Higashidori and expertise, we delivered a large inland GTCC Reactors in operation Nuclear Power *Five units have been shut Station power plant in FY2019, which helps to improve the down Ohma Nuclear Reactors approved for Power Station resilience of the entire power grid (Refer to “First installment license amendment Tomari Nuclear Inland GTCC Thermal Power Plant in Japan: Reactors under assessment for Power Station new regulatory requirements Generator Onsite Manufacturing” on page 164). In Reactors that have not applied for assessment addition, we are currently working on the design, Reactors to be decommissioned Number is the number of reactor manufacture, and construction of ultra-supercritical Kashiwazaki-Kariwa Nuclear Power Station 12 Tsuruga Nuclear thermal power generation* and biomass power Power Station Ohi Nuclear generation projects with the goal of completing them Power Station Shika Nuclear Power Station on schedule. Takahama Onagawa In terms of after-sales services, we not only pro- Nuclear Nuclear Power Power Mihama Station Station Nuclear vide periodic repair and lifetime extension, but also Power Station Fukushima aiichi Nuclear Power Station actively apply the latest technologies to improve Shimane Nuclear Power Station Fukushima aini efficiency and operation and significantly increase Nuclear Power Station
the rate of uptime through preventive maintenance Genkai Nuclear Power Station Tokai/Tokai ai-ni using various diagnostic technologies (Refer to Power Station Ikata Nuclear “Online Gas Analysis for Deterioration Diagnosis of Power Station Sendai Nuclear Hamaoka Nuclear Rotating Machinery Stator Winding” on page 169). Power Station Power Station
Furthermore, we are enhancing our service bases Reference: “Current Status of Nuclear Power Plant Operation,” Ministry of Economy, Trade and Industry (Original, Japanese) outside Japan to include the United States, Taiwan, Made by Fuji Electric by reference to Nuclear Power and Energy rawings South Korea, Southeast Asia and the Middle East by the Japan Atomic Energy Relations Organization while also developing indigenous repair techniques so that we can minimize outage time at power Fig. 2 Operational status of nuclear power plants in Japan plants. In addition, we are actively developing diag- nostic systems that utilize robotics to substantially Damage Compensation and Decommissioning reduce equipment downtime. Facilitation Corporation (NDF) and other organiza- Looking ahead, we aim to continue creating cus- tions are working intently to achieve decommission- tomer value by actively offering services while reli- ing plans throughout the country by taking mea- ably meeting the diverse needs of our customers. sures against contaminated water and developing technologies and designing equipment to extract
9. Nuclear Power Field fuel debris. At the same time, progress is also be- Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s ing made in regard to the nuclear fuel cycle, in According to the supply and demand outlook which spent fuel is reprocessed and the recovered for electricity in the 5th Strategic Energy Plan, uranium-plutonium mixture is put to good use in a nuclear power is positioned as a power source that harmonious manner. In the field of nuclear power, will supply 20-22% of all electricity in 2030. This ongoing solution technologies are, for the time be- energy mix ratio is consistent with the goal of reduc- ing, required for both restarting and decommission- ing greenhouse gas emissions, including CO2 emis- ing of power plants. sions, from energy sources by 26% compared to 2013 Fuji Electric has been developing the decommis- levels. However, since ensuring safety is the prior sioning technology for nuclear power plants, includ- condition, restarting or constructing nuclear power ing the fuel removal and fuel cleaning of the Monju plants have to satisfy new regulatory standards that prototype fast breeder reactor, as well as the design draw on lessons learned from the accident at the of cement solidification equipment to process- dis Fukushima Daiichi Nuclear Power Plant. In line mantled waste (Refer to “Unloading and Handling with these new standards, 24 reactors are scheduled Technology of the Fuel Assembly in Prototype Fast for decommissioning, 9 reactors have been restarted Breeder Reactor ‘Monju’” on page 174). as of the end of 2019, and 27 reactors are on track to Moreover, in order to safely process, dispose be restarted in the future. Figure 2 shows the opera- and store the radioactive waste generated during tional status of nuclear power plants in Japan. the operation and decommissioning of nuclear facili- At present, the National Institute for Nuclear ties, we have been conducting research and devel-
*12 Ultra-supercritical-pressure high temperature and high pressure con- exceed 24.1 MPa and 566 °C respectively, the thermal power generation: ditions that exceed the critical pressure of state is called ultra-supercritical-pressure A highly efficient power generation water. Operating temperature and pressure thermal power generation. system that reduces the thermal energy re- have been gradually made higher to increase quired to vaporize water by placing it under the efficiency of power generation. When they
Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society: Current Status and Future Outlook 145 opment in collaboration with Jacobs Engineering ation) as an integral component of energy systems Group Inc. of the United States on a solidifica- will not be limited to efficiently creating electricity, tion technology that uses geopolymers, which have but will also extend to the delivery of the effective many prominent features (Refer to “Radioactive use of electricity and heat. Going forward, Fuji Waste Treatment Using the Advanced ‘SIAL®’ Electric will continue to focus on its customers, lis- Solidification Technology” on page 180). ten to their opinions, and work with them to create Furthermore, in order to contribute to the nu- customer value. With this in mind, we remain com- clear fuel cycle, we are providing technologies and mitted to innovating technologies and enhancing our products that comply with the new regulatory stan- services. dards, including uranium-plutonium mixed oxide We plan to continue making significant contri- (MOX) fuel production facilities, remote handling butions to the realization of a sustainable society by equipment, earthquake-resistant switchboards, and providing safe, secure and environmentally friendly fire prevention and extinguishing facilities. energy creation and social infrastructure solutions.
10. Postscript
The role of power generation (i.e., energy cre-
146 FUJI ELECTRIC REVIEW vol.66 no.3 2020
tion equipmenttomanyprojectsinIndonesia. market andhasdeliveredgeothermalpowergenera 2010 to2018. from been remarkable, increasing approximately 60% ticular, Indonesia’sgrowthofpowerplantcapacityhas MW.Inpar MWto14,600 increasing from10,716 was approximately 1.4 times more than that in 2010, As showninFig.1,thepowerplantcapacityasof2018 ity aroundtheworldhasbeenincreasingyearbyyear. 1. Introduction Fig.1 Worldwidegeothermalpower generationmarkettrends *
Muara LabohGeothermalPower PlantinIndonesia Power GenerationBusinessGroup, FujiElectricCo.,Ltd. The installedgeothermalpowergenerationcapac nti ae,w nrdc h 52 MWMuara In thispaper,weintroducethe85.26 Fuji Electric regards Indonesia as an important
Installation capacity by country (MW) motors andturbinegovernorregulationsystem. engineering oftheentireplantastechnicalleaderanddeliveredequipment,suchasteamturbine,generator, with PT.SupremeEnergyMuaraLaboh.AsasubcontractortoSumitomoCorporation,wewereresponsibleforthe Sumitomo CorporationandPT.RekayasaIndustri,alocalengineeringcompany,hadcompletedturnkeycontract MW)inSumatra,Indonesiastartedoperation,forwhichaconsortiumof plant (powergenerationcapacity:85.26 regarded and trusted by the country’s electricity industry. On December 2019, the Muara Laboh geothermal power 10,000 12,000 14,000 16,000 2,000 4,000 6,000 8,000 Fuji Electric has a market share of approximately 50% in geothermal power plantsin Indonesia, being highly Fuji Electric has a market share of approximately 50% 0 0 10,716 2010 1,197 MW HATTORI, Yasuyuki 12,635 (Year) 2015 ABSTRACT (1)(2)(3) - - - 1,340 MW entire plantandsuppliedthemainequipment. Fuji Electric was in charge of the engineering ofthe 2019. December in operation commercial started which Laboh GeothermalPowerPlantinSumatra,Indonesia, ttlo 2 MW,Sumatra),WayangWinduUnit1 (total of226 generation facilities, including Ulubelu Units 1 to 4 Electric hasdeliveredlargescalegeothermalpower second largest holder of geothermal resources. Fuji MW.ThismakesIndonesiatheworld’s ity of29,000 tential resourcesequivalenttopowergenerationcapac 2. It isestimatedthatIndonesiahasgeothermalpo Geothermal ResourcesinIndonesia * 14,600 2018 1,948 MW United States Indonesia Philippines Turkey New Zealand Mexico Italy Iceland Kenya Japan Others Total 147 - -
issue: Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society (110 MW, Java) and Wayang Windu Unit 2 (117 MW, Java). However, the geothermal potential resources Nearest airport that have been developed and used for power genera- Padang Western Power plant tion amount to only approximately 7% of the potential. Sumatra construction site It is supposed that Indonesia still has much room for Muara Laboh geothermal power plant development. The Indonesian government has announced a policy to increase total Kuala Lumpur Malaysia Mount Kerinci installed capacity to 7,200 MW by 2025 for geothermal Singapore power generation, which does not emit CO2 during the Western Sumatra power generation process, in response to growing envi- Indonesia ronmental awareness worldwide. In this respect, it is Jakarta expected that there will be a greater demand for geo- thermal power generation in the future. The power generation capacity of a geothermal power plant depends on the pressure, temperature and Fig.3 Construction site location of Muara Laboh Geothermal fl ow rate of the geothermal resources (steam and hot Power Plant water) supplied from production wells. Muara Laboh Geothermal Power Plant shows that Indonesia has a potential of high-quality and very-high-energy geother- mal resources. Among Indonesia’s resources, Sumatra Island is estimated to have the greatest potential of geothermal resources. In addition to the Muara Laboh Geothermal Power Plant, there are many other future geothermal power generation projects in Sumatra Is- land.
3. Project Overview
As shown in Fig. 2, Sumitomo Corporation formed a consortium with the Indonesian leading engineering Courtesy of PT. SEML fi rm PT*1. Rekayasa Industri (REKIND), and the con- sortium undertook an engineering, procurement and Fig.4 Panoramic view of the power plant construction (EPC) contract with independent power producer PT. Supreme Energy Muara Laboh (PT. SEML) in March 2017. PPA*1 PT. SEML concluded a power purchase agreement PT. PLN PT. SEML Jacobs*3 (PPA) with Indonesia’s state-owned power company Technical consultant EPC PT. PLN. Fuji Electric participated in the project as CONTRACT*2 the technical leader under Sumitomo Corporation and
Sumitomo Corporation PT. Rekayasa Industri undertook the engineering of the entire plant, design and supply of power generation equipment. Consortium ○Steam gathering system, leader transmission lines, switching Figure 3 shows the construction site of the geother- stations esign and procurement for mal power plant. It is located in western Sumatra. the auxiliary equipment of the power plant Figure 4 shows a panoramic view of the power plant. SUB-CONTRACT ○Civil engineering and construction ○Installation work 4. Overview of the Power Generation Equipment
Technical leader Fuji Electric ○ esign and supply of separator Figure 5 shows the confi guration of a typical geo- ○ esign and supply of power thermal power plant. generation equipment ○ ispatch of technical advisors A geothermal power plant is connected with pro- (construction and commissioning) duction wells, which extract hot water and steam from *1 PPA: Purchase power agreement *2 EPC contract: Engineering, procurement and construction contract the ground, and reinjection wells, which return the hot *3 Jacobs: Jacobs Engineering Group, Inc. water to the ground, through transport pipes. Produc- tion wells produce two-phase geothermal resources Fig.2 Project structure consisting of steam and hot water. The two-phase fl uid is delivered to the separators and they separate *1 PT is an acronym for Perseroan Terbatas, which repre- the two-phase fl ow into steam and hot water. Muara sents a limited liability company in Indonesia. Laboh Geothermal Power Plant utilizes a double fl ash
148 FUJI ELECTRIC REVIEW vol.66 no.3 2020 High-pressure High-pressure separator scrubber Two-phase Production flow High-pressure steam well Turbine and generator Gas extraction system
Low-pressure Low-pressure Steam ejector Outside air Hot water separator scrubber Low-pressure Non- steam condensable Vacuum pump gas
Reinjection hot water rain rain Cooling tower Cooling water
Condenser
Warm water
Reinjection well Hot well pump
Fig.5 Main system equipment for the geothermal power plant system*2, in which high-pressure steam and hot water cold end. are separated by the high-pressure separators, and the The cooling system mainly consists of a condenser, hot water is then flashed*3 for vapor-liquid separation hotwell pumps and cooling towers. It is a circulation by the low-pressure separator to extract low-pressure system in which hot water from the condenser, which steam. In the steam pipe leading from the separators condenses the steam used for power generation, is to the turbine, if liquid and moisture are not properly sent to the cooling towers by the hotwell pumps, to discharged from the steam, water hammer*4 can occur, be cooled. The cooled water is returned to the con- Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s causing damage to the pipe and connected equipment. denser to be used to condense the steam. The gas Therefore, drain pods are installed at regular intervals extraction system has the ability to remove non-con- to remove the liquid. The high-pressure steam and densable gases (CO2, H2S, air, etc.) contained in the low-pressure steam are controlled at a constant pres- steam from the condenser using steam ejectors and sure. After further removing moisture using scrub- vacuum pumps, and then discharge them outside the bers, it is sent to the steam turbine to generate elec- system. Geothermal steam contains a large amount tricity. At the same time, the separated hot water is of non-condensable gas, and geothermal power plant returned to the ground through reinjection wells. requires a larger capacity gas extraction system than Geothermal power generation capacity depends conventional thermal power plants. The gas extrac- on the steam characteristics (pressure, temperature, tion system is important, since if such system does not flow rate) obtained from the production wells and is work properly, it leads reduction of the vacuum in the therefore determined by natural conditions. In order condenser, which in turn will reduce the turbine out- to optimize the performance of the entire plant under put and negatively impact the overall performance (ef- the natural conditions, it is important to keep the pres- ficiency) of the plant. sure in the condenser as low as possible to maximize In addition to the main equipment mentioned the energy drop between the inlet and outlet of the above, Fuji Electric also supplied the equipment for turbine using cooling and gas extraction systems called power generation process, such as auxiliary cooling wa- ter equipment and chemical injection equipment. *2 Double-flash system: High-pressure steam and low-pres- sure steam are extracted by separators in two stages to 5. Basic Specifications of Main Equipment utilize geothermal resources without waste. *3 Flash: Re-evaporation of high-temperature high-pressure Table 1 shows the basic specifications of the main water in a low pressure environment. equipment. The steam turbine, generator, motors, *4 Water hammer: A phenomenon in which shock is quickly and (TGR: turbine governor regulators) system were transmitted through a fluid contained in a piping system manufactured by Fuji Electric. Some of the other com- due to pressure surge in the piping. ponents, such as cooling tower, separators, and FRP
Muara Laboh Geothermal Power Plant in Indonesia 149 Table 1 Basic specifications of main equipment Steam turbine Generator Gas extraction system Cooling tower
Single cylinder double flow ◦ Totally enclosed air-cooled Hybrid steam ejector and Forced draft counter flow Reactive turbine ◦ ◦ ◦ ◦ turbo generator vacuum pump type Type ◦ Downward exhaust
◦ Capacity: 105 MVA ◦ Gross output: 85.26 kW ◦ Configuration: ◦ Excitation: Brushless ◦ Cells: 8 ◦ Inlet steam pressure: ◦ 2 × 50% Two-stage ejector + ◦ Voltage: 11 kV ◦ Frame: Concrete High pressure of 0.84 MPa abs vacuum pump ◦ Frequency: 50 Hz ◦ Design wet-bulb tempera- Low pressure of 0.39 MPa abs ◦ 1 × 50% Three-stage ejector ◦ Rated power factor: 0.85 ture: 18.3 °C Rotational speed: 3,000 min−1 (backup) ◦ (lag) Basic specifications piping, were procured from within Indonesia in order to increase the ratio of domestically sourced products to meet the local content requirement.
6. Project Features
6.1 Inconvenient transport conditions and harsh weather Muara Laboh geothermal power plant is located about 10 km away from Mount Kerinci (elevation: 3,805 m), which is the highest peak in the Barisan Mountains Range in western Sumatra. It takes about five hours by car from the nearest airport in Padang to Muara Laboh site which is located in an isolated area with only small villages. It is located in the moun- tains at an altitude of 1,400 m and has a lot of rainfall Fig.6 Transportation of the generator stator throughout the year. Another challenge was that the communication network in the area was not robust. Most of the roads for the transportation are in moun- 6.2 High-level requirements from independent power tainous area, with steep gradients and narrow widths. producer, PT. SEML Therefore, we had to carefully investigate the routes in This was a project finance*5 project, so the profit- preparation of the transportation. This was challeng- ability of the project was more rigorously assessed ing because of the large size of the equipment, but we than the projects for national utilities. Since PT. successfully delivered all equipment without any prob- SEML had to demonstrate to investors that the project lems. was worthy of financing, our consortium was requested In particular, it was difficult to transport large to explain how it could meet all the requirements generator stator, since this item was the largest mass in terms of technology, quality, delivery, and safety (approximately 100 t) of all items procured by Fuji throughout the project period. In this regard, we re- Electric. Although transportation on the steep moun- sponded to inquiries as promptly as possible by updat- tain roads was a big risk, by identifying the challenges ing technical specifications, drawings, quality records, in advance and taking precautions, we actually trans- process progress reports so that the latest project sta- ported it without any problems (see Fig. 6). Since tus could be ascertained clearly by stakeholders. it was difficult environment to receive support from Fuji Electric gained the trust of PT. SEML by be- Japan, we actively recruited local technical advisors ing sincere in our efforts and responding to some is- to work in collaboration with Fuji Electric personnel. sues raised by PT. SEML and consultants who had This team carried out the installation and commission- good understanding of the requirements of geothermal ing work and successfully installed, commissioned and power plants. As a result, we have successfully com- delivered all the equipment to PT. SEML. pleted the project on schedule.
*5 Project finance: A way for a company to procure funds based upon the projected cash flows of the project.
150 FUJI ELECTRIC REVIEW vol.66 no.3 2020 2014 Update Report”, https://www.geothermal-energy. 7. Postscript org/pdf/IGAstandard/WGC/2015/01001.pdf, (accessed 2020-07-14). Indonesia has a national policy to expand the use (2) “2016 Annual U.S. & Global Geothermal Power Pro- of geothermal energy through the utilization of geo- duction Report”, https://www.eesi.org/files/2016_An- thermal power plants. Fuji Electric plans to continue nual_US_Global_Geothermal_Power_Production.pdf, to cooperate with Indonesia to achieve its SDGs. In re- https://www.thinkgeoenergy.com/the-top-10-most- cent years, Fuji Electric has also been getting into new read-geothermal-news-of-2019-on-thinkgeoenergy/, markets such as Kenya and Mexico while also under- (accessed 2020-07-14). taking geothermal power generation projects in Japan. (3) THINK GEONERGY. https://www.thinkgeoenergy.com/ We remain dedicated to helping achieve a low-carbon the-top-10-most-read-geothermal-news-of-2019-on- society throughout the world by utilizing our geother- thinkgeoenergy/, (accessed 2020-07-14). mal power generation technology.
References (1) “Geothermal Power Generation in the World 2010- issue: Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s
Muara Laboh Geothermal Power Plant in Indonesia 151 Japan’s Largest Class Storage-Battery Equipped Mega Solar Power Plant SHIIBASHI, Tetsuya * NAZUKA, Takehiro * SATO, Tomoki⁑
ABSTRACT
The Suzuran Kushiro-cho Solar Power Plant was completed and came online in February 2020. Fuji Electric undertook an engineering, procurement and construction (EPC) contract for the power plant with GPD Suzuran Solar K.K., which was jointly established by Tokyu Land Corporation, Mitsubishi UFJ Lease & Finance Company Limited, and the Green Power Development Corporation of Japan. Solar power generation, which is a fluctuating natural power source, produces large output fluctuations due to variations in solar radiation. As a result, there is concern that this will impact the frequency and voltage fluctuations of power grids. Fuji Electric used its unique output fluctuation mitigation technology along with storage battery equipment to meet the requirements of the output fluctuation mitiga- tion measures established by the power company.
1. Introduction
The Suzuran Kushiro-cho Solar Power Plant was completed and came online in February 2020. The power plant is Japan’s largest class storage-battery equipped mega solar power plant with a total output of 59.4 MW AC, consisting of 92.2 MW of solar cells (302,500 solar panels) and 25.3 MWh of lithium-ion batteries on approximately 163 ha of land in Kushiro- cho, Kushiro-gun, Hokkaido, Japan. By using Fuji Electric’s output fluctuation mitigation technology and storage battery system, the power plant satisfies the requirements of the output fluctuation mitigation mea- Fig.1 Panoramic view of the Suzuran Kushiro-cho Solar Power sures (1% or less per minute) set by Hokkaido Electric Plant Power Co., Inc. Fuji Electric undertook the project as an EPC contract concluded with GPD Suzuran Solar K.K., jointly established by Tokyu Land Corporation, Mitsubishi UFJ Lease & Finance Company Limited, and the Green Power Development Corporation of Japan. The construction work started in July 2017 Monitoring Substation Transmission Power system equipment line tower substation and was delivered to the customer in February 2020. 66 kV 66 kV Interconnec- In this paper, we will describe the construction of AC AC tion point Output control the Suzuran Kushiro-cho Solar Power Plant and its (1%/min. fluctuation power generation and storage-battery systems. mitigation control)
22 kV 22 kV 2. Overview of the Suzuran Kushiro-cho Solar AC AC Power Plant PCS for solar cells, boost PCS for storage batteries, boost The power plant consists of solar cell modules, sub- transformer, and ring-main unit transformer, and ring-main unit substations, storage batteries, and substation facilities. 1,000 V 600 V It was constructed and installed on unused land in C C Charge Kushiro-cho. ischarge Figure 1 shows a panoramic view of the Suzuran Solar cells Storage battery Kushiro-cho Solar Power Plant. The 92.2 MW of DC Fig.2 Overall system configuration * Power Generation Business Group, Fuji Electric Co., Ltd. ⁑ Corporate R&D Headquarters, Fuji Electric Co., Ltd.
152 output from the solar cells is converted to 59.4 MW of Table 1 Solar cell specifications AC output using 60 of Fuji Electric’s 1,000-kW power Item Details conditioning systems (PCSs). The plant boostd the Cell type Monocrystalline silicon output to 66 kV using the substation facilities and No. of cells used 60 transmit it to Hokkaido Electric Power Co., Inc. via its Basic Module dimensions 1,650 × 992 × 40 (mm) power lines while mitigating output fluctuation using specifica- 5,400 Pa (positive load) Max. load resistance the accompanying storage battery system. tions 2,400 Pa (negative load) The power plant is expected to generate approxi- Mass 19 kg mately 105,518 MWh per year, which is equivalent Module delivery qty. 302,500 to the annual power consumption of approximately Max. output P max 305 W 21,300 ordinary households. Module efficiency 18.63% Figure 2 shows the overall system configuration. Max. output operating 32.80 V voltage V pm 3. Main Equipment Specifications for Solar Max. output operating 9.30 A Power Generation System current I pm Open-circuit voltage 40.30 V A solar power generation system is a facility that V oc collects the DC power generated by solar cell modules Electrical Short-circuit current I sc 9.83 A charac- P temperature coef- into the PCSs, where the power is then converted into teristics max 0.39%/°C ficient − AC and then transmitted. V temperature coef- oc 0.29%/°C ficient − 3.1 Solar cell modules I temperature coef- sc 0.05%/°C The plant uses monocrystalline silicon modules, ficient each rated at 305 W, that is capable of providing stable Max. system voltage 1,000 V power generation performance even in cold regions. As Cell temperature 25 °C, Testing conditions shown in Fig. 3, 20 solar cell modules are arranged in AM1.5, irradiation amount (STC) 2 4 rows and 5 columns on the solar panel mounting and 1,000 W/m connected in series to form an array. The output volt- age per array is 656 V DC with an output capacity of A spiral-bladed pile is used in areas where the ground 6.1 kW. The outputs generated by the arrays are ag- strength is weak (N-value less than 4) (see Fig. 4). gregated at the junction boxes and sent to the input In order to withstand wind loads, piles were driven terminals of the PCSs located in the sub-substation. to a maximum depth of 12.5 m to ensure the bearing Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s Table 1 shows the specifications of the solar cells. capacity. A total of 60,500 piles are driven into the ground, with each array utilizing four piles. The solar 3.2 Solar panel mountings and foundations All foundations supporting the solar panel mount- ings consist of pile foundations. Most of this power plant is located on soft ground, a characteristic that is peculiar to the Kushiro region. The foundation there- fore uses piles with a blade at the tip of the shaft. A single-bladed pile is used in areas where the ground strength is relatively strong (where an N-value*1 of 4 or higher is confirmed by the standard penetration test).
(a) Spiral-bladed pile (b) Single-bladed pile
Fig.4 Pile structure
*1 N value: The strength of the ground obtained by stan- dard penetration testing (JIS A 1219). This is the num- ber of strikes required to drive the standard penetration test sampler mounted to the tip of a boring rod into the Fig.3 Solar panel mountings and solar cell modules ground at the specified penetration rate of 30 cm.
Japan’s Largest Class Storage-Battery Equipped Mega Solar Power Plant 153 panel mountings installed at the top of the piles are Table 3 Specifications of the PCS for solar power generation made of highly corrosion-resistant galvanized steel Item Basic specifications strip so that it can survive the next 20 years. The Type PVI1000BJ-3/1000 mounting angle for each module is configured to 20 Rated voltage 750 V DC, 380 V AC degrees in consideration of snow accumulation and in- Max. system voltage 1,000 V (DC) stallation efficiency. The total number of solar cell ar- 1,000 kW (operation limited to Capacity rays installed is 15,125. 990 kW) Table 2 shows the specifications of the solar panel Rated frequency 50/60 Hz mounts. Output power factor >0.99 (rated output) Output current distor- <5% (rated output) 3.3 Sub-substations tion factor (total) Sub-substations consist of PCSs that convert the Output current distor- <3% (rated output) power generated by the solar cells from DC to AC, a tion factor (each) Conversion efficiency transformer that boosts the power, and ring-main unit 98.8% (Max.) panels that branch the cables connected to the substa- Conversion efficiency 98.5% tion facilities. (Euro) It uses the new “PVI1000BJ” PCSs, which are Overload capacity 100% continuous equipped with Fuji Electric’s own outdoor-air forced Noise 80 dB (A) cooling system (see Fig. 5 and Table 3). This PCS System protection OV, UV, OF, UF is more compact and lighter than the previous Islanding detection (pas- Detection of voltage phase jump “PVI1000.” It reduces the required installation area sive) and facilitates on-site transport and installation work. Islanding detection (ac- Frequency feedback method with step The power converted into AC by the PCS is tive) injection stepped up to 22 kV by the booster transformer and Voltage rise suppression Reactive power output and effective function power suppression Table 2 Specifications of solar panel mountings FRT function Yes Item Basic specifications Cooling system Forced-air cooling Foundation struc- Dimensions W2,622 × D1,252 × H1,920 (mm) Pile foundation ture Mass Approx. 1,800 kg Carbon steel for general Material Qty. 60 Mounting structures foundation Length 4.5 to 12.5 m Qty. 60,500 then sent to the 22-kV switchboards in the substation Tip shape With blade facilities through the ring-main unit (RMU). Installation loca- Outdoor tion 3.4 Storage battery system Highly corrosion-resistant Material The storage battery system consists of lithium-ion galvanized steel strip Solar panel batteries, PCSs for storage batteries, booster trans- Array structure 4 rows and 5 columns mount formers and RMJ panels. It is used to control the Qty. 15,125 output fluctuations caused by sudden change in insola- Designed wind load 30m/s tion, which is a weakness of solar power plants. The Snow load 70 cm PCSs for storage batteries charge and discharge the storage batteries in response to commands from the substation facilities to suppress output fluctuations. The power output from the PCS is stepped up to 22 kV using a booster transformer and then sent to the 22-kV switchboards of the substation facilities via the RMU. The storage battery modules utilize lithium-ion batter- ies with good charge-discharge characteristics. The lithium-ion batteries have the output char- acteristics that are highly dependent on the ambient temperature, and they are thus stored in the container designed for storage batteries (see Fig. 6). The con- tainer uses an air conditioner to appropriately regulate its temperature. Table 4 shows the specifications of the PCS for storage batteries. Fig.5 New “PVI1000BJ” PCS for solar power generation
154 FUJI ELECTRIC REVIEW vol.66 no.3 2020 (a) 72-kV C-GIS and 66-kV booster transformer
Fig.6 Containers for storage batteries (back right) and for PCSs for storage batteries (front)
Table 4 Specifications of PCS for storage batteries Item Basic specifications Type PVI800-3/750 Rated voltage 550 V DC, 270 V AC Max. system voltage 800 V (DC) Capacity 750 kW
Rated frequency 50/60 Hz (b) 24-kV extra-high-voltage switchboard Output power factor >0.99 (at rated output) Output current distor- <5% (at rated output) Fig.7 Substation facilities tion factor (total) Output current distor- <3% (at rated output) tion factor (each) Table 5 shows the specifications of the storage bat- Conversion efficiency tery system, and Table 6 shows the specifications of the 98.1% (Max.) substation facilities. Conversion efficiency 97.8% (Euro) Table 5 Specifications of storage battery system Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s Installation location Indoor (installed inside container) Item Basic specifications Noise 75 dB (A) Storage Cell type Lithium-ion battery System protection OV, UV, OF, UF battery Qty. 5 racks × 64 banks Islanding detection (pas- Detection of voltage phase jump Capacity 79.1 kWh sive) Voltage 504.0 to 705.6 V Islanding detection (ac- Frequency feedback method with step tive) injection Max. discharge 158.3 kW (2C) power Voltage rise suppression Reactive power output and effective function power suppression Standard charging 64 A (0.5C) Rack current FRT function Yes Operating tem- Cooling system Forced-air cooling 23 °C ± 5 °C perature Dimensions W2,750 × D900 × H1,950 (mm) No. of storage 12 modules Mass Approx. 2,580 kg modules Qty. 64 Qty. 320 Capacity 128 Ah (6.6 kWh) Voltage 42.0 to 58.8 V 3.5 Substation facilities No. of storage cells 28 Module 14 series connected × The power output from the PCs for solar power Internal cell wiring generation and PCSs for storage batteries are sent to 2 parallel connected Total No. of mod- 24-kV extra-high-voltage switchboards [see Fig. 7(b)] 3,840 ules installed in the substation. The power is boosted to Capacity 64 Ah (235.5 Wh) 66 kV by the main transformer and then transmit- Cell Voltage 3.0 to 4.2 V ted to Hokkaido Electric Power Co., Inc. through gas- insulated switchgear (C-GIS) [see Fig. 7(a)]. The power plant is 2 km away from the interconnection point, and it constructed its own power line to the grid.
Japan’s Largest Class Storage-Battery Equipped Mega Solar Power Plant 155 Table 6 Substation facility specifications Power at interconnection point Item Basic specifications Composite output Pg+Pb Storage-battery output Pb Type SDDa608 Solar power Rated voltage 72 kV generation System controller Charge-discharge command value Po Rated current 1,200 A output Pg − Fluctuation + C-GIS Power receiving Overhead single-line power component removal type reception filter Stabilization Installation loca- PV-PCS HL*1 Storage Outdoor target value battery tion 1 Pa No. of units 1 1+sTf 2 Filter time constant Tf Oil-filled self-cooling PV LL* Type Variable time constant three-phase transformer control function 22 kV (primary) / 66 kV (sec- Rated voltage ondary) Variation of Tf based on magnitude of Po Main Rated capacity 60,000 kVA *1 HL: Upper limit of fluctuation component removal filter transformer *2 LL: Lower limit of fluctuation component removal filter Star (primary) / Wiring method Delta (secondary) Insulation type A type Fig.8 Overview of output fluctuation mitigation control Qty. 1 value obtained by removing the fluctuation component Enclosed outdoor self-stand- Type ing type from PV output P g using a fluctuation component - re 24-kV Rated voltage 24 kV moval filter (P g - P a = P o). According to the charge- extra-high- Rated bus current 1,600 A discharge command value P o, the P b, negative phase voltage switchboard Rated frequency 50 Hz output of fluctuation component, is output from the storage batteries. The PV output fluctuation is thus Total No. of 25 panels canceled out and the combined output (P g + P b) is smoothed at the interconnection point. The filter time constant T f of the fluctuation com- 4. Output Fluctuation Mitigation Control ponent removal filter is variable in the system control- ler as shown in Fig. 8. This approach is referred to as Solar power generation, a fluctuating natural variable time constant control. power source, greatly fluctuates in output mainly- de In this control method, the filter time constant of pending on the amount of solar radiation. As a result, the fluctuation component removal filter is optimally there are concerns that this will impact the power grid set according to the magnitude of the storage battery in terms of frequency and voltage fluctuations. charge-discharge command value P o. Specifically, The In order to maintain power quality despite the out- filter time constant is lengthened when the PV output put fluctuation of natural power sources, some power fluctuation is large and shortened when the PV output companies are requiring output fluctuation mitigation fluctuation is small. This variable time constant con- measures to be taken for newly interconnected large- trol can more effectively reduce unnecessary charging scale solar power and large-scale wind power facilities. and discharging than control methods that use a fixed In this respect, Hokkaido Electric Power Co., Inc., filter time constant while maintaining the output fluc- whose service area includes the plant site, also set tuation rate at the interconnection point to 1% or less forth requirements regarding output fluctuation miti- per minute. This can help reduce the total capacity of gation measures. Therefore, the rate of output fluc- the storage battery. tuation for solar power generation must be 1% or less Figure 9 shows the simulation results for out- per minute for the rated output. In order to satisfy put fluctuation mitigation. The storage batteries are this requirement, the plant is equipped with an output charged and discharged to cancel out the output fluc- fluctuation mitigation control function that is capable tuation in solar power generation. This method is used of smoothing the combined output at the interconnec- to smooth the power at the interconnection point. Dur- tion point at the solar power plant by charging and ing the smoothing, the output fluctuation rate of the discharging the storage batteries according to the solar power at the interconnection point is maintained at 1% power output. or less per minute (594 kW/min).
4.1 Overview of control 4.2 Evaluation of control performance Figure 8 shows the system configuration and -con Figure 10 shows the actual results on February 1, trol structure. The output fluctuation mitigation con- 2020, a day on which the PV output fluctuation was trol determines the charge-discharge command value considerably high during the continuous commission- P o by calculating the difference between PV output ing work. P g and the stabilization target value P a, which is the As shown in Fig. 10, the PV output fluctuated
156 FUJI ELECTRIC REVIEW vol.66 no.3 2020 80,000 80,000 Solar power Power at Solar power 11:30 14:00 generation output 60,000 generation output interconnection point 60,000 Power at interconnec- tion point 40,000 40,000
20,000 20,000
0 0 Output (kW) Output (kW)
−20,000 −20,000 Storage-battery Storage-battery output output −40,000 −40,000 07:00 07:30 08:00 08:30 09:00 09:30 10:00 06:00 09:00 12:00 15:00 18:00 Time Time (a) Each output waveform (a) Each output waveform
1,000 1,000
750 594 kW/min. (1%/min. of rated output) 750 594 kW/min. (1%/min. of rated output)
500 500
250 250
0 0
−250 −250 07:00 07:30 08:00 08:30 09:00 09:30 10:00 06:00 09:00 12:00 15:00 18:00 Output fluctuation rate (kW/min.) Time Output fluctuation rate (kW/min.) Time (b) Output power fluctuation rate at (b) Output fluctuation rate (absolute value) interconnection point (absolute value)
Fig.9 Simulation results Fig.10 Results of continuous operation test on February 1, 2020 greatly from around 11:30 am to 2:00 pm, but the power at the interconnection point was regulated to 5. Construction Work maintain an output fluctuation rate of 1% or less per minute due to the charging and discharging of the The construction of the Suzuran Kushiro-cho Solar storage batteries, thereby smoothing the power at the Power Plant took 2 years and 8 months from the start Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s interconnection point in a stable manner. Due to mea- of construction in July 2017 to the completion of com- surement errors, the value exceeded 594 kW/min at missioning and delivery to the customer in February a few points, but this was still within the acceptable 2020 as planned. The construction started by build- range of the control. ing the road to enter the site and by mowing the site. The construction started with civil work, followed by electrical work one after another from where solar cell
Table 7 Outline of power plant construction process 2017 2018 2019 2020 No. Year/month Construction work type 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3
I Civil engineering work ◀ (1) Design / preparation / clearing work (2) Creation of management and construction roads (3) Construction of pile foundations and mounting assemblies
(4) Panel installation Power receiving Start of operation ◀ (5) Fence construction (6) Equipment foundation work II Electrical work (1) Construction in vicinity of solar cell arrays (2) Solar power generation equipment installation work (3) 22-kV trunk line construction (4) Storage battery system installation work (5) Storage battery system wiring work (6) Interconnection substation facilities construction III 66-kV private power line construction IV Field test adjustment V Comprehensive test adjustment
Japan’s Largest Class Storage-Battery Equipped Mega Solar Power Plant 157 mountings has been installed. During the latter half of storage-battery equipped mega solar power plant. the construction period, we installed electrical equip- The storage battery technology that we refined ment, such as PCSs and storage batteries, and did the during this project will be used to eliminate the out- required electrical wiring work. After completing the put instability of solar power plants, considered as construction work, we carried out the commissioning their disadvantage. In addition to stabilizing output and then handed over the power plant to the customer. for power grids, this technology can also be applied to Table 7 shows the overall process we followed to stabilize the output of the distributed power sources construct the power plant. expected to be developed in the future. We plan to con- tinue contributing to the increased use of renewable 6. Postscript energy sources.
In this paper, we described Japan’s largest class
158 FUJI ELECTRIC REVIEW vol.66 no.3 2020 ⁑ low CO capacities of100kWorless,reducedrunningcosts, small at even efficiently generation high fuels, of riety cells havemanyfeatures:capableofrunningonava eration systemswithinternalcombustionengines,fuel achieve low-carbonsocieties.Comparedwithcogen type of next-generation energy source that helps to gen. Theuseoffuelcellshasbeenincreasingasone electrochemical reaction between hydrogen and oxy March 2020. delivered atotalof100unitsinJapanandabroadas water withageneratingcapacityof100kW,wehave ing in cogeneration systems that use electricity and hot ties with relatively high energy costs and by specializ ability. Bytargetingsmall-andmedium-scalefacili includes peripheralequipmenttoimproveitsmarket started sellingtheall-in-one“FP-100i”package,which phoric acidfuelcell (PAFC) in1998,and2010 1. Introduction Korea. outlining ourhistoryofdeliveringfuelcellstoSouth Korean market.Wewill also providesomeexamples and requirementsofphosphoricacidfuelcellsinthe specifications the as well as Korea, South in cells fuel describe the background to the increasing adoption of has beenprogressingquickly.Inthispaper,wewill *
Power GenerationBusinessGroup, FujiElectricCo.,Ltd. Fuji ElectricKoreaCo.,Ltd. Phosphoric Acid FuelCellsfor theKorean Market Fuji Electriccommercializeda100-kW-classphos Fuel cellsgenerateelectricitydirectlyfromthe In recent years, the use of fuel cells in South Korea such assaunas,andareexpectedtobewidespread. longed operationinJapan.Withthesefeatures,thefuelcellshavebeenbeingintroducedintowarmbathfacilities, tions. Inaddition,weprovidestableoperationusingremotemonitoringandensurehighreliabilitybasedonourpro- cold tolerance.FujiElectrichasachievedthesespecificationsthroughourresearchanddevelopmentopera- cells includingcompatibilitywithKoreanfuelgases,installationareareduction,simplifiedon-siteconstruction,and power producersinSouthKorea,FujiElectric’stargetcustomers,definethespecificationsforphosphoricacidfuel Portfolio Standard(RPS),aregulationthatcoversnewenergysourcesincludingfuelcells.Small-andmedium-sized 2 emissions,andenvironmentallyfriendly. The introductionoffuelcellshasbeenexpandinginSouthKoreafollowingtheadoptionRenewable KAWAKAMI, Koji ABSTRACT * ------HORIUCHI, Yoshimi mandated supply must be achieved by supplying elec inthetargetyearof2022.The in2012to10% 2% mandated supplyratioisscheduledtoincreasefrom based on the Renewable Portfolio Standard (RPS). The renewable ornewenergysources,includingfuelcells produce a certain percentage of their electricity from a capacityof500MWormorehasbeenobligatedto sources. Since2012,large-scalepowerproducerswith to promotethespreadofrenewableenergypower for renewableenergyfrom2002to2011asameasure 2. ate electricityfromnewandrenewableenergysources As aresult,large-scalepowerproducersmustgener is (RECs) sued by new and renewable energy power producers. certificates energy renewable purchasing tricity fromnewandrenewableenergysourcesorby Fig.1 Fuelcellpowersellingscheme forsmall-andmedium- South Korea enacted a feed-in tariff (FIT) scheme Renewable EnergyandtheFuelCellMarket South Korea’sPoliciesforAdoptingNewand Power selling scale powerproducersinSouth Korea Korea ElectricPower Corporation revenue REC revenue Small- andmedium-scalepowerproducers (Power generatedbyfuelcell) Large-scale powerproducers Korea PowerExchange transmission Grid power ⁑
Korea EnergyAgency REC sales REC issuance
159 - - -
issue: Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society based on the RPS measures and small- and medium- scale power producers expect to earn profits through Exhaust heat treatment system (air-cooled radiator) the acquisition and sale of REC credits, in addition to the sales of electricity. The adoption of fuel cells has 2.5 3.4 m thus been expanding particularly in recent years. m Fuji Electric’s 100-kW phosphoric acid fuel cells are targeted at small- and medium-scale power produc- ers who are making use of the above-mentioned REC credits. Figure 1 shows an overview of the power sell- 2.2 m ing scheme for the fuel cell power generation described above. 5.5 m
3. Fuji Electric’s Fuel Cells Water treatment system Electric panel
3.1 Overview and main specifications Auxiliary equipment compartment Figure 2 shows the appearance of the FP-100i of Fuji Electric’s all-in-one phosphoric acid fuel cell pack- ages. Main equipment compartment Table 1 shows the main features of the FP-100i. Main fuel cell equipment Three types of fuel cells are available: city gas, for
Nitrogen Partition supply system wall
Fuel gas inlet Fuel cell unit (Stack)
Fig.3 Structure of the “FP-100i”
which infrastructure is already in place; biogas (sew- age digester gas), which is being used as a renewable energy source; and pure hydrogen, which is expected to be a next-generation fuel. In addition to cogeneration applications, the FP-100i offers some optional features, such as disaster-response functions capable of grid in- dependent power supply using LP gas as a backup, and fire-prevention functions that can supply clean, low- Fig.2 Appearance of the “FP-100i” phosphoric acid fuel cell oxygen air. Figure 3 shows the structure of the FP-100i. The Table 1 Main specifications of the “FP-100i” FP-100i comes with a package structure that facili- Item Specification tates on-site installation. It has a width of 2.2 m and Fuel City gas Biogas Pure hydrogen height of 2.5 m (3.4 m after installation) allows for easy Output 105 kW (Gross output) transport by truck. It incorporates a nitrogen supply system and water treatment system, which has been Output voltage/ 210 V/50 Hz or 60 Hz frequency conventionally separate facilities. Moreover, the air- Generating effi- cooled radiator for exhaust heat treatment is installed 42% 40% 48% ciency (LHV)* in the ceiling. Adopting this structure significantly Heat output 123 kW 116 kW 99 kW help reduce the wiring and piping work required for Overall effi- on-site installation and halve the required installation 91% 84% 93% ciency (LHV) area. NO : 5 ppm or less X NO , SO , Exhaust gas SO , dust: Below detection X X X dust: None limit 3.2 Delivery records and operation performance Dimensions W2.2 × D5.5 × H3.4 (m) Figure 4 shows our delivery records of the 100-kW fuel cells. Table 2 shows the country of delivery and Mass 14 t 13.5 t the type of gas used, and Table 3 shows the facilities of * LHV: A “heating value” that corresponds to the amount of heat dissi- pated when a unit amount of fuel under certain conditions is com- the delivery site. pletely combusted adiabatically (i.e., no heat loss) and the resulting Since 1998, we have delivered 100 units inside combustion gas is cooled to its original temperature. There are two types of heating values, namely, a higher heating value (HHV), which and outside Japan as of March 2020. Our fuel cells includes the latent heat of steam, and a lower heating value (LHV), are compatible with a variety of fuel gases, including which does not include it. city gas, natural gas, digester gas and pure hydrogen.
160 FUJI ELECTRIC REVIEW vol.66 no.3 2020 120 110 elivery qty. 100 Cumulative total 10,000 hrs. 100 90 or more 80 80 70 30,000 hrs. or more Japan 60 60 50 Abroad elivery qty. 40 40 60,000 hrs. 30 or more 20 20 elivery qty. and cumulative long-term operation time (qty.) 10 0 1999 to 2001 to 2006 to 2011 to 2016 to 0 2000 2005 2010 2015 2019 Mar. 2020 Fiscal year Fig.5 Historical change in the number of fuel cells in cumula- Fig.4 Deliveries of 100-kW phosphoric acid fuel cells (FP-100i tive long-term use after FY2010) reached 130,000 hours (about 15 years). Table 2 Number of units delivered and gas types by country Figure 5 shows the number of units delivered as of Gas type March 2020 and the number of units whose cumula- Country Qty. Natural Digester Pure tive operating time has exceeded 10,000, 30,000, and City gas gas gas hydrogen 60,000 hours. By leveraging the knowledge we have Japan 67 28 6 32 1 gained from past operation results and utilizing the United States 2 - 2 - - remote monitoring system described below, we have Germany 10 - 10 - - analyzed the causes of past operation failures and South Korea 19 1 18 - - have deliberated and implemented countermeasures to achieve stable operations. France 1 - 1 - - South Africa 1 1 - - - 4. Fuel Cells for South Korea Total 100 - In this section, we will describe the specifications Table 3 PAFC installation sites required for fuel cells for the Korean market. Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s Installation site Japan Abroad Sewage treatment 4.1 Compatibility with Korean Fuel Gases 31 0 plants Table 4 shows a comparison of typical fuel gases Office and commercial in Japan and South Korea. Typical South Korean gas 6 4 buildings includes a higher proportion of methane and provides Factories and gas com- 8 10 lower calories than Japanese city gas. Fuji Electric panies calculates the flow rate of steam and fuel gas tobe Saunas 0 8 supplied to a reformer based on past installation and Hospitals 7 0 operation records inside and outside Japan to deter- Universities 5 1 Warehouses 0 5 Table 4 Comparison of fuel gases between Japan and South Others 10 5 Korea City gas 13 A Natural gas Subtotal 67 33 Molecular Component (Tokyo Gas Co., (Daegu City, formula Total 100 Ltd.) South Korea)
Methane CH4 89.60% 93.10%
Ethane C2H6 5.62% 4.47% The main facilities of the delivery sites of the fuel cells Propane C H 3.43% 1.53% have been sewage treatment plants, office and com- 3 8 mercial buildings, factories, gas companies, saunas, Butane C4H10 1.35% 0.69% and hospitals. Fuel cells are primarily used for cogen- Pentane C5H12 - 0.02% eration systems. The reliability and durability of Fuji Nitrogen N2 - 0.20% Electric’s phosphoric acid fuel cells have been dem- Total - 100.00% 100.00% Heating onstrated at actual sites. Some of the delivered units Unit value 40.6 38.5 MJ/Nm3 overtook major renovations, or overhauls, including (LHV*) the replacement of main equipment, such as cell stacks * LHV: Lower heating value. See the footnote in Table 1. and reformers, and the cumulative operation time has
Phosphoric Acid Fuel Cells for the Korean Market 161 mine an optimum ratio of the flow rates according to The system stores operation data on a cloud server the composition and calorie of the fuel gas used at each and enables remote updating of fuel cell software from installation site. maintenance Pcs. By logging into the cloud server from a mobile device, users can view operation data 4.2 Simplification of on-site construction wherever and whenever they want. The FP-100i is an all-in-one package and suitable for small- and medium-scale power producers in South 5. Examples of Delivering Fuel Cells to South Korea. It can be installed in narrow areas such as city Korea centers where it is not possible to install large facili- ties. Furthermore, the FP-100i is designed to enable As we mentioned previously, we have been increas- speedy wiring and piping work, thereby facilitating its ingly delivered the FP-100i to South Korea since 2017 adoption in South Korea. in response to the Korean government’s incentives for introducing new and renewable energy sources. In this 4.3 Resistant to cold climates section, we will describe a few delivery examples. The high altitudes and elevations of Korean cities, Figure 7 shows the fuel cells delivered to Yuil such as Seoul, can result in extremely cold tempera- Industry. The customer initially ordered 5 fuel cells, tures, going down to -10 °C or colder in winter. and then made a follow-up order increasing the total In the past, indoor installation was required in amount of currently-operating fuel cells to 8. cold regions where temperatures drop to -5 °C. How- Figure 8 shows a fuel cell delivered to the rec- ever, as shown in Fig. 3, the FP-100i package comes reation center of KT Corporation (formerly Korean with an internal partition wall that isolates the aux- Telecom). Although the installation area was very nar- iliary equipment compartment area from freezing row, we successfully installed the fuel cell by taking temperatures. By optimally controlling the heat dis- advantage of the fuel cell’s small footprint. The rec- sipation and air supply and exhaust of the equipment reation center is located in a high-altitude area that in that area, the fuel cell makes sure that the tempera- experiences snowfall and very cold temperatures in the ture in that area never falls below 0 °C, even when the outside temperature is -20 °C. This enables the fuel cell to be installed outdoors even in cold regions. Since it is resistant to cold climates, the fuel cell can operate smoothly even in the very cold winter cli- mates of South Korea.
4.4 Stable operations with remote monitoring The phosphoric acid fuel cells being used in South Korea can also take advantage of Fuji Electric’s cloud- based remote monitoring system for fuel cells that en- ables our engineers in Japan to monitor the operating status and make software changes via the Internet. This allows us to respond quickly in the event of an abnormality, even if it occurs outside of Japan. Figure Fig.7 Delivery example of eight 100-kW fuel cells for Yuil 6 shows an overview of the remote monitoring system. Industry
Cloud server
Terminal Virtual dedicated line Internet authentication server
Check operation wherever and whenever Terminal Terminal Terminal
Smartphone PC, etc. Maintenance PC Fuel cell Fuel cell (Country A) (Country B) Fig.8 Delivery example of one 100-kW fuel cell for KT recre- Fig.6 Cloud-based fuel cell remote monitoring system ation center
162 FUJI ELECTRIC REVIEW vol.66 no.3 2020 winter. The fuel cell is used in a cogeneration system (power generation + exhaust heat utilization) that runs smoothly all year round. Figure 9 shows fuel cells delivered to a sauna in Cheonho. In order to make effective use of the park- ing lot next to the sauna’s building, the customer built a new two-story steel frame structure. We installed FP-100i fuel cells on top of the structure. Saunas are typically located in urban areas where installation space is limited. By inventing installation measures as this example, we met the customer’s requirements. Figure 10 shows fuel cells delivered to a sauna in Dongho. This sauna was also located in an urban area. We installed three units in the available space Fig.10 Delivery example of three 100-kW fuel cells for a sauna of the indoor golf driving range on the roof of the sauna in Dongho building. In addition to the above examples, there are an in- facilities where there is high demand for heat. The creasing number of examples where we have installed FP-100i has the advantage of efficiently utilizing the FP-100i fuel cells for small-scale power producers in waste heat created during power generation. sauna buildings, heated swimming pools, and other 6. Postscript
In this paper, we described our phosphoric acid fuel cells for South Korea. By taking advantage of the specifications and features of the FP-100i, we plan to continue marketing the fuel cell to mainly small- and medium-scale power producers who utilize cogenera- tion. We are also aiming to introduce the fuel cells to new markets in South Korea by capitalizing on the fuel cell’s ability to run on a variety of fuels such as biogas and hydrogen. Fuji Electric is committed to realizing a low-carbon, Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s sustainable society to mitigate global warming by le- veraging our proven fuel-cell technologies and develop- ing and expanding applications that take advantage Fig.9 Delivery example of two 100-kW fuel cells for a sauna in of the features of our fuel cells in Japan and abroad in Cheonho order.
Phosphoric Acid Fuel Cells for the Korean Market 163 First Inland GTCC Thermal Power Plant in Japan: Generator Onsite Manufacturing TANIFUJI, Satoshi * NAKAYAMA, Hiroki * MIZUMOTO, Takayuki *
ABSTRACT
Fuji Electric undertook an engineering, procurement and construction contract to deliver gas turbine combined cycle power generation facilities to the Moka Power Plant operated by Kobelco Power Moka Inc., the first large-scale inland gas thermal power plant in Japan. The facilities include two generators for the gas turbine and two generators for the steam turbine. Although the plant was constructed inland, we could not use inland transportation to deliver the main equipment especially the generators after completion due to the regulations such as the dimensions and the load capacity. Therefore, we adopted new structures, such as block stator structures, to use inland transporta- tion and established onsite manufacturing technology, making it possible to locally manufacture generators for inland installation.
1. Introduction and tsunami and was selected as a leading example in terms of building national land and energy resilience A combined cycle power generation system, which by the Cabinet Secretariat and the Ministry of Econ- consists of a gas turbine and steam turbine, is charac- omy, Trade and Industry (METI). terized by its high power generation efficiency and low The plant consists of the most advanced open-cycle environmental load. It has been widely used in recent single-shaft gas turbine and a steam turbine, each hav- years and becoming increasingly important(1). Large ing respective shafts. Indirect hydrogen-cooled genera- combined-cycle thermal power plants often utilize sea- tors are used for gas turbine power generation and in- water to cool the steam they use. This makes coastal direct air-cooled generators are used for steam turbine areas suitable for such plants. However, coastal ar- power generation. The inland plant uses a large air- eas come with the risk of earthquakes and tsunamis. cooled condenser that cools and circulates water. Therefore, these types of large-scale power plants often On the other hand, since the plant was constructed need to adopt countermeasures against natural disas- inland, it required on-site manufacturing of various ters in order to ensure a stable supply of electricity. large equipment. Specifically, we could not use inland This is especially true in Japan. In contrast, inland transportation to deliver completed generators due to areas are not susceptible to the tsunami damage that constraints such as the dimensions and the load capac- frequently accompanies earthquakes. This means that ity. To overcome this challenge, we developed a new the installation of large-scale thermal power gen- generator that had structures suitable for inland in- eration facilities inland can provide a more reliable stallation and on-site manufacturing. Table 1 shows means of ensuring a stable supply of electricity even the main specifications of the gas turbine generator in the event of an earthquake. They can serve as valu- and Fig. 1 shows the cross-sectional view. able decentralized backup power source for the entire In this paper, we will describe the features and Tokyo metropolitan area, which is highly dependent on electricity generated in coastal areas, to stably supply Table 1 Plant specifications electricity. Item Specification Fuji Electric undertook an engineering, procure- Output 470 MVA ment and construction (EPC) contract to deliver gas Voltage 22 kV turbine combined cycle (GTCC) power generation facil- Power factor 0.9 ities (2 624 MW) to the Moka Power Plant operated by × Frequency 50 Hz Kobelco Power Moka Inc., the first large-scale inland Stator: Indirect hydrogen Cooling system ◦ gas thermal power plant in Japan. We have recently ◦Rotor: Direct hydrogen delivered four generators, including two for the gas Hydrogen gas pressure 0.5 MPaG turbine and two for the steam turbine. This project is Rotational speed 3,000 min−1 recognized as a decentralized large-scale power source Excitation method Static with low risk of natural disasters such as earthquakes Overall length 13.9 m Mass 456 t * Power Generation Business Group, Fuji Electric Co., Ltd.
164 Table 2 On-site manufacturing Stator winding Rotor Stator core Seal ring Issue Challenge Hydrogen Pressure Stator frame Main terminal Transportation constraints Planning of measures to en- gas cooler plate ◦The stator frame exceeds able local transportation the transportation con-
3.1 Block stator structure The stator frame is a large component (approxi- mately 10 m long, 5 m wide, 5 m high, and 85 tons in mass) used to cover the core. Its complex internal structure is designed to hold the pressurized hydro- gen gas as a refrigerant and to form the cooling path. Hydrogen gas has excellent cooling performance, but Stator frame and core assembly is prone to explosion when mixed with oxygen. There- fore, the stator frame must be completely airtight and Fig. 2 Generator manufacturing process strong enough to contain a hydrogen gas explosion.
First Inland GTCC Thermal Power Plant in Japan: Generator Onsite Manufacturing 165 each block [see Fig. 4 (6)] in the laminating direction. By stacking them, the total length of the stator core reached approximately 6 m. These tens of thousands of laminated electrical steel sheets were then tightened using pressure plate placed at both ends of the core, clamping bolt and core fixing beams placed around the periphery. They were further secured by support rings from the outer peripheral side (see Fig. 4). Typically, when a stator core is manufactured in a factory, a global vacuum pressure impregnation insula- tion system is used to impregnate the laminated sta- tor core and stator winding with insulation resin as an integrated unit. Vacuum impregnation fills the space between the core, winding and the wedge with resin, Fig.3 Block stator frame which adheres strongly to prevent loosening. However, for this project, there was no global vac- The manufacture of the stator frame consists of uum pressurized impregnation equipment available at three processes: canning (welding), machining, and as- the work site. Therefore, we developed a donut-shaped sembly. To ensure quality, it is essential that the work block-fixing core in which several blocks at both ends on-site is performed at the same quality standards of the core are laminated at the factory and vacuum as that in the factory. However, during the product impregnated, as shown in Fig. 5. This structure pro- planning stage when there were still uncertainties re- vided the same effect of resin hardening as the global garding the on-site working environment, we expected vacuum pressure impregnation insulation system that major risks that involve schedule recovery in the event we normally employ. This created a structure that can of decreased quality and other on-site problems. In or- prevent loosening of the core over time and withstand der to ensure product quality, it was thus most impor- the electromagnetic force applied to the edge of the tant for us to design the products so that the amount core due to magnetic flux leakage. Moreover, by manu- of on-site work is minimized. Therefore, we developed facturing these donut-shaped block-fixing cores at the the block structure of the stator frame shown in Fig. 3. factory and then delivering them to the work site, we This structure integrated the four pieces of the stator shortened the construction period for on-site core stack frame divided longitudinally with bolts. It allowed us manufacturing and meet the delivery deadlines. to complete the stator frame on-site by simply assem- bling the frame and welding some of the parts inside 3.3 Technology for on-site manufacturing the frame, minimizing the amount of on-site work as In addition to quality, cost, and delivery, it was much as possible. important to create a working environment and safety conditions that were equal to or better than those of 3.2 Block stator core structure the factory. In order to shorten the construction period The stator core is made from 0.5-mm thick elec- for the on-site manufacture of the generator, we had to trical steel sheets, punched into a fan shape, coated simultaneously start preparing the stator frame and with insulating varnish and laminated into blocks of equipment for on-site manufacturing. After arrang- several tens of mm. The ventilation path for cooling ing the work area with the engineering contractor, we was formed by arranging duct pieces [see Fig. 4 (7)] in
Lifting fixture (1) Support ring
(2) Core fixing beam
(3) Pressure plate
(4) Clamping bolt
(5) Clamping finger
(6) Stator core
(7) uct piece Stator core
Fig.4 Stator core end structure Fig.5 Block stator core
166 FUJI ELECTRIC REVIEW vol.66 no.3 2020 brought in specialized equipment for the generator the progress and quality of the products via web con- stator. In preparation for this, we carefully identified ferencing. factors related to the working environment, such as temperature, humidity, and amount of dust to deter- 4. On-Site Generator Manufacturing mine control items. Of course, it was also important to consider safety. (1) Stator frame assembly (1) Installation and transport of specialized equip- Stator frame assembly at the factory is performed ment to the site with the frame lying on its side, but in this project, In order to install and transport the large special- we needed to stack parts vertically due to the limited ized equipment required for manufacturing the genera- work space. The position of each block stator frame tor stator, we first secured a work area for manufactur- needed to be aligned with high precision. In order to ing the generator by coordinating with the engineer- do this, it was necessary not only to control the level- ing contractor and adjusting the overall power plant ness of the building floor, but also to precisely adjust construction plan. Next, we calculated the maximum the vertical and horizontal positions of each block sta- load of each work area and requested the engineering tor frame and their respective circumferential posi- contractor to ensure that each work area can bear the tions. Therefore, we developed various adjustment load. jigs and built scaffolding on the inside and outside the (2) Measures for controlling dust on the work site frames with safety measures implemented to complete It was important to control the amount of dust at the work. After assembling the block stator frames, the work site to prevent foreign matter from enter- we laid the integrated stator frame on its side. Typi- ing the insulating material during generator stator cally, in a factory, two overhead cranes would be used manufacturing. Therefore, we set up a curing house to do this laying work, but the cranes available in the for respective assembly processes of core stacking and building at the work site lacked the capacity to do this stator winding (coil). In particular, the core stacking work. Therefore, we did the laying work outdoors. We work involved work at heights of up to 10 m, and we collaborated with a logistics company to lay the stator installed a large curing house to ensure the required frame using two hydraulic cranes. Figure 6 shows the seismic strength. The curing houses had top and side laying work. walls capable of being opened, making it easy to carry (2) Stator core stacking in and out the components. They also used an air- Figure 7 shows the core stacking work. We devel- conditioning system to prevent condensation by con- oped a micro-motion device so that we could adjust the trolling the daily temperature and humidity. In addi- levelness of the surface plates and the position of the tion, we regularly measured the amount of dust as a vertical surface plates. The device’s adjustments fully Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s pre-work inspection to maintain the factory-level envi- satisfied the factory control values and simplified the ronment and to control quality on-site. adjustment process. (3) Quality control (3) Stator winding assembly To eliminate on-site rework processes, it was im- Figure 8 shows the stator winding assembly pro- portant to reduce risks at the investigation stage and cess. Although the overhead crane in the building at establish on-site quality control. To reduce risks, we the site could not be used for this work because the prepared work procedure manual appropriate for the work fell outside of its range of motion, we developed on-site work environment, removed potential risks, mobile assembly jigs and part transfer jigs to complete and when necessary, revised the structure to suite the the work. We enhanced the safety of the work by uti- manufacturing on-site. We also tried to promote the lizing elevating scaffolds that matched the size of the manufacturing of the products to the extent possible in our factory in advance. Verifying the assembly process at the factory allowed us to identify problems in ad- vance and take measures to address them. In terms of quality control, we established a management system that was at least as good as that of our factory. We co- operated with personnel in charge of customer reviews and product audits to prepare a procedure manual, so that concerned personnel could review the work be- fore it began. Besides the witness inspection, a qual- ity verification system was prepared for customers to check product quality at each individual work step. In addition to these measures, the responsible personnel on-site and those in the factory used IT equipment to closely exchange information. They shared the infor- mation on the product state in real time and checked Fig.6 Laying the block stator frame on its side
First Inland GTCC Thermal Power Plant in Japan: Generator Onsite Manufacturing 167 Fig.7 Assembly of stator core Fig.9 Assembly of stator core and block stator frame
the cores circumferentially, the cores were turned cir- cumferentially by varying the amount of jacking on one side of the PJS. When inserting the stator frame into the stator core, we adjusted the parallelism of the core and stator frame by changing the speed in the di- rection of travel of one side of the PJS. We used the micro-motion adjustment jigs and PJS to perform pre- cise adjustments to complete the assembly work.
5. Postscript
In this paper, we described the technology used to perform on-site manufacturing of generators used in Japan’s first inland GTCC thermal power plant. Dur- Fig.8 Stator coil assembly ing the design and development stage, we developed a method of creating stator frame blocks to deal with plant, as well as sliding scaffolds with handrails. To transportation constraints. We also described an ex- ensure safety environment, we set up a simple house ample of how we enhanced technology for stacking for coating work inside the curing house, installed an core ends. With regard to technologies used for on-site exhaust system, and used airline respirators. manufacturing, we gave examples of the various types (4) Stator frame and core assembly of equipment used and the working environment. By We inserted the stator frame into the cylindrical establishing technology for installing generators in stator core to complete the generator stator. Normally, inland sites as mentioned above, Fuji Electric success- we would do this using an overhead crane, but the fully completed the delivery of the generators on sched- mass of the completed stator exceeded the capacity of ule. the crane in the building at the work site. Instead of We plan to continue contributing to society by de- the overhead crane, we used a power jacking system veloping technologies that enable us to provide prod- (PJS). A PJS was constructed with large jacks ar- ucts that meet the needs of our customers. ranged like a gate. It lifted a large object and moved it only in the direction of the rail. It could not move References it with fine precision transversely. To overcome this (1) Yamazaki, M. et al. Global VPI Insulated Indirectly weakness, we developed temporary placement jigs Hydrogen-Cooled Turbine Generator for Single-Shaft and a stator core micro-motion device to adjust the Type Combined Cycle Power Generation Facilities. positioning during assembly work. Figure 9 shows a FUJI ELECTRIC REVIEW. 2013, vol.59, no.2, p.113- photo of the PJS assembly. To adjust the position of 117.
168 FUJI ELECTRIC REVIEW vol.66 no.3 2020
machine, leadingtosuddenaccidentssuchasbreak and collidewithothermajorpartsinsidetherotating this way,centrifugalforcecancausethemtodislodge corrode andbreak.Whenmetalpartsaredamagedin can causethemetalpartsinsiderotatingmachinesto structure. We have conventionally identified malfunc identified conventionally have We structure. its stator winding as an instance of rotating machine (1) 2. system toquantitativelymeasureO or accidents.Thismethodusesasimplemeasurement plan to prevent customers facingthese types of failures insulation sothatwecanprovideoptimalmaintenance the degreeofsurfacedeteriorationstatorwinding We, however,haveestablishedamethodtoestimate to corrosivegasescausedbyinsulationdeterioration. tating machineaccidents,suchasbreakingdowndue down. emission ofcorrosivegasessuchasO discharges ontheinsulatingsurfacecanresultin ing surfaceofthestatorwindingdeteriorates,partial ated withoperation.Inparticular,whentheinsulat mechanical, thermalandenvironmentalfactorsassoci over timeduetothecompositestressofelectrical, chines, such as generators and motors, deteriorates 1. Introduction moisture in the air to produce HNO (nitrogen oxide).Inaddition,NO operation. *
Power GenerationBusinessGroup, FujiElectricCo.,Ltd. Online Gas Analysis for DeteriorationDiagnosisof The statorwindinginsulationofrotatingma Figure 1showsthecrosssectionof a generatorand There arenoknowninstancesofFujiElectric’sro Features andMeasurementMethod operators toquicklyandaccuratelyunderstandthestateofinsulationdeterioration. fline (duringstoppage)inspectionscanperformmoremultifacetedanddetailedassessmentsdiagnoses,allowing deterioration ofstatorwindinginsulation.Combiningthisonline(duringoperation)gasanalysiswithconventional- uses asimplemeasurementsystemtoquantitativelymeasurecorrosivegasesanddeterminethedegreeofsurface machines, potentially leading to a sudden accident. To solve this problem, Fuji Electric established a method that ted whentheinsulatingsurfaceofstatorwindingdeteriorates.Thiscandamagemetalpartsinsiderotating trical, mechanical,thermalandenvironmentalfactorsduringoperation.Inparticular,corrosivegaseswillbeemit- Features The statorwindinginsulationofrotatingmachinesdeterioratesovertimeduetothecompositestresselec- Rotating MachineryStator Winding NAKAYAMA, Akinobu X 3 cancombinewith (nitric acid). This 3 3 andNO (ozone)andNO X during ABSTRACT X ------
* advantages: of online(in-operation)gasanalysishasthefollowing tions decreasesduetopostponement. tween periodic inspections or if the frequency of inspec riod oftimeiftherehappenstobealonginterval However, malfunctionscangounnoticedforalongpe diagnosis andinspectionduringperiodicinspections. tions anddeteriorationinrotatingmachinesthrough Fig.1 Crosssectionofageneratorandstatorwinding ISHII, Yuichi (b) (a) (c) In contrast,deteriorationdiagnosisthatmakesuse Unlike theconventionalmethod, largeinstru Always measurableeveninoperation. riod oftime(halfaday). Measurements canbecompleted inashortpe to diagnoseinsulation. ments ornumerouspersonnel arenotrequired Stator winding (b) Statorwindingcross-section (a) Generatorcross-section *
Stator ironcore Conductor insulation Main iron core Stator Wedge 169 - - - - -
issue: Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society Table 1 shows several types of samples, including (a) enerator one with no deterioration and four with simulated de- terioration and damage at the rotating machine stator winding. We placed these sample bars in a metal case simu- Stator frame lating a rotating machine frame and then applied an Access cover electric field of approximately 3 kV/mm to measure the maximum discharge rate Qmax using a partial dis- charge meter. Using a gas detector tube, we measured the concentration of O3 and NOX in the case after one hour of continuously applying the electric field. Figures 3, 4 and 5 show the measurement results. A relatively high Qmax was obtained for sample bar (b), whose OCP in the iron core was partially lost, and as sample bar (c), whose OCP was entirely lost on the collection port whole circumference surface. For sample bars (b) and (b) Measurement (c), the concentration of O3 was as high as 37 ppm and example Table 1 Sample types Fig.2 Measurement example of using online gas analysis for a Model bar Remark generator a ◦No deterioration For comparison ◦Simulate OCP* erosion in the sta- (d) Quantitatively measuring O3 and NOX can eval- tor iron core b - uate the degree of deterioration in the insulat- ◦OCP is partially lost on the sur- face of the model bar. ing surface of the stator winding. ◦Simulate OCP* erosion in the sta- (e) By combining insulation diagnosis with precise tor iron core c - diagnosis at the time of shutdown and periodic ◦OCP is lost on the whole circum- inspections, it can perform more multifaceted ference surface of the model bar. and detailed evaluations and diagnoses. ◦Simulate OCP* erosion outside of the iron core (the outlet of the (2) Measurement method iron core) OCP partially re- d Figure 2 shows a measurement example of using ◦OCP is partially lost on the whole mains on the surface online gas analysis for a generator. During the opera- circumference surface of the model bar. tion of the rotating machine, a sample of gas from in- Compared with sur- Internal main insulating layer is side the machine is collected through a screw hole from e ◦ face discharge due to deteriorated (void, peeling). which the screw has been removed that fixes the -sta OCP deterioration tor frame access cover. The gas concentration is then OCP: Outer corona protection measured using an O3 or NOX gas detector tube. Mea- suring O3 and NOX gases is used to diagnose the dete- rioration for the insulation surface of the stator wind- Type of evaluation sample bar ing because the type and concentration of the gases (a) Undeteriorated sample (b) OCP in stator iron core (partially lost in multiple locations) will vary depending on the degree of deterioration. (c) OCP in stator iron core (lost on the whole circumference) (d) OCP outside stator iron core (partially lost on the whole circumference) 3. Development Overview (e) oids and peeling in the main insulation layer
When a rotating machine operates, the stator ≥ , winding will create a small amount of partial dis- , charge, which will increase as it ages and deteriorates. 22, 2 , We began its diagnosis by determining the concentra- tions of O3 and NOX that exist when calculating the , 7, amount of partial discharge. (pC) max Q
3.1 Relationship between partial discharge and generated , gas We used a stator bar coil (a bar-shaped sample coil ≤2 that simulates a stator winding) to investigate the re- lationship between the occurrence of partial discharges (a) (b) (c) (d) (e) due to deterioration and the gas concentrations of O3 and NOX. Fig.3 Sample type and Qmax
170 FUJI ELECTRIC REVIEW vol.66 no.3 2020 glass). The sample bars were subjected to accelerated 350 deterioration through use of a high-temperature, high-
300 280 frequency voltage-applied testing instrument. We measured the onset time of erosion in association with 250 OCP deterioration. We placed the sample bar with on- 200 going OCP erosion in a glass tube, applied a voltage of approximately 3 kV/mm, and then injected an air flow 150 of 100 ml/min from one side to measure the O3 concen- tration using a gas detector tube. concentration (ppm) 100 3
O Figure 6 shows the erosion onset time measure- 50 37 ment results for different OCP base materials. The N. . 1.5 N. . onset time of erosion for OCP materials was as follows: 0 (a) (b) (c) (d) (e) the polyester had the shortest time at approximately 100 hrs.; the aramid was next at approximately 520 Fig.4 Sample type and O3 concentration to 740 hrs.; and the glass had the longest time at ap- proximately 800 hrs. The experiment showed that the onset time of erosion for each material was not very 6 dependent on the electric field strength. In addition, 5 we discovered that the selection of insulation materials to be used played an important role in suppressing the 4 discharge deterioration of OCP on the stator winding surface and in ensuring durability. Figure 7 shows the results of investigating the re-
concentration (ppm) 2 X Polyester Aramid Glass NO 1.8 N. . N. . N. . N. . 0 (a) (b) (c) (d) (e) 1.6
1.4 Fig.5 Sample type and NOX concentration issue: Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s 1.2 280 ppm respectively, while NOX was below the detec- tion limit. 1.0 Absent
Sample bar (d), whose OCP was partially lost to Electric field strength ratio* simulate the outlet of the iron core, had the highest 0.8 10 100 1,000 10,000 Qmax of more than 100,000 pC. O3 was only 1.5 ppm, Erosion onset time (hrs.) which was less than that of sample bars (b) and (c). * Electric field strength ratio: The ratio of an appied electric field strength However, 5 ppm of NOX was detected. Sample bar value to the value for insulation design (e), simulating deterioration inside the main insula- tion layer, had a Qmax of 24,500 pC, which was almost Fig.6 Erosion onset time for different OCP base materials the same as the Qmax of 22,000 pC for sample bar (c), whose OCP in the iron core was entirely lost. For sam- 25 ple bar (e), both O3 and NOX were below the detection limit. 20 These results indicate that the existence of O3 and NOX is mainly due to the discharge on the surface of the stator bar, and their amount is related to the loca- 15 tion of the discharge and the magnitude of Qmax. 10
3.2 Relationship between the external OCP material and concentration (ppm) 3
O 5 generated gas Section 3.1 showed that the degree of OCP deterio- 0 ration influenced the maximum discharge amount due 0 3 6 9 12 to surface discharge as well as the amount of gener- OCP erosion area (cm2) ated gas. After this, we investigated the dependence of the Fig.7 Relationship between OCP erosion area and O3 concen- OCP on base materials (three types: polyester, aramid, tration
Online Gas Analysis for Deterioration Diagnosis of Rotating Machinery Stator Winding 171 lationship between the eroded area and the generated Table 3 Recommended measurement frequency gas concentration using a sample bar with ongoing Detection of Recom- OCP erosion. We discovered that the amount of gener- corrosive gas mended Remarks frequency ated O3 increased as the erosion of OCP progressed on O3 NOX Unde- Unde- About once a the stator winding surface. - We also found that the onset time of OCP erosion tected tected year Unde- About once a was strongly affected by the OCP material, and wider Detected - tected year erosion areas caused more O3 gas to be generated. Recommendations for About every precise diagnosis (open Detected Detected 4. Application Examples six months inspection) and insula- tion diagnosis 4.1 Measurements using actual equipment perform trend management to identify sudden changes This online gas analysis is mainly used for air- in deterioration. For generators where O and NO cooled turbine generators having a capacity of 3.3 kV 3 X are detected, we recommend online analysis every six or higher. In 2017, we began taking measurements months because of concerns regarding corrosion and during operation and have continued to diagnose gen- deterioration of metal parts due to the acidic atmo- erators of our own and other manufacturers, both in- sphere created by HNO . In order to understand the side and outside Japan. 3 magnitude of deterioration and to obtain evidence of Table 2 shows an overview of the measurement mechanical integrity, we also recommend combining results. The measurement targets include a range of online analysis with the insulation diagnosis and pre- generators from newly built ones to those that were 36 cise diagnosis that are performed during offline (during years old. Among 55% of measured generators includ- shutdown) inspections described in the next section. ing new ones, O3 and NOX were below the detection limit, and we determined that the insulation on the stator winding surface was in good condition. 4.2 Combination of online and offline inspections Inspections for rotating machines consist of simple Table 3 shows the recommended measurement inspections and full-scale inspections, which include frequency for online gas analysis. We have discovered precise diagnosis and electrical insulation diagnosis. that it is important to continue measurements and As shown in Fig. 8, A comprehensive evaluation that combines the conventional offline diagnostic services Table 2 Summary of measurement results with this online gas analysis offers even more multifac- Percentage of all measure- O detection NO detection 3 X ments (%) eted and detailed evaluations. Undetected Undetected 55 ≥0.1 ppm Undetected 27 ≥0.1 ppm ≥0.05 ppm 18
Causes of insulation ○Electricity ○Thermal deterioration ○Machinery ○Environment
○Surface of stator winding Typical stator winding ○Main insulation layer of stator winding deterioration location ○Insulating parts
Conventional diagnostic service (offline) New diagnostic service (online) Precise diagnosis and electrical Reliability evaluation eterioration diagnosis of rotating machine stator insulation diagnosis (remaining lifespan prediction) winding using online gas analysis ○Visual inspection ○ issipation factor Evaluation of the remaining lifespan of ○Insulation resistance test rotor windings by combining deterioration iagnosis of the degree of stator winding surface test ○Partial discharge diagnosis methods and multiple regression deterioration ○ C absorption test test methods Measurement of O3 and NOX concentrations inside ○AC test ○High-voltage test equipment during operation Physicochemical insulation and thermal deterioration diagnosis Comprehensive diagnosis of stator winding iagnosis of the deterioration of various deterioration through various tests insulating parts based on the results of thermal analysis of insulating materials collected from actual equipment
○Comprehensive evaluation of diagnosis ○Proposal of maintenance and upkeep plans
Fig.8 Comprehensive evaluation of stator winding using a combination of online gas analysis and conventional diagnostic services
172 FUJI ELECTRIC REVIEW vol.66 no.3 2020 used to determine health and the onset of deterioration 5. Postscript over time on the surface of windings. Observed dete- rioration transition will give an indicator of operation In this paper, we described deterioration diagnosis risks. of rotating machine stator windings using online gas In the future, we plan to continue promoting more analysis. effective and accurate evaluation of rotating machines Fuji Electric recommends periodic diagnosis with by combining online gas analysis measurement data online analysis. Even when there are no problems with actual states of deterioration and damage con- with machinery, continuous online analysis can be firmed through periodic inspections. issue: Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s
Online Gas Analysis for Deterioration Diagnosis of Rotating Machinery Stator Winding 173 Unloading and Handling Technology of the Fuel Assembly in Prototype Fast Breeder Reactor “Monju” KOGA, Kazuhiro *
ABSTRACT
The prototype fast breeder reactor Monju is currently in its first stage of decommissioning. The fuel han- dling facility system provided by Fuji Electric was used to unload and handle the fuel assembly as scheduled. Fuji Electric provided technical assistance, such as dispatching engineers to the JAEA, and overcame problems that had not arisen before to complete the project, thus proving our solid technology for the unloading and handling of the fuel assembly. We will continually acquire and evaluate actual operation data on the fuel handling facility system. Re- flecting the results into the design will contribute to the development of next-generation fast reactors, which are es- sential part of supporting a low-carbon society.
1. Introduction
Monju is a prototype reactor of fast breeder reac- tors (nuclear reactors designed for breeding nuclear fuel) (see Fig. 1). Light water reactors are common nu- clear reactors that use water as a coolant, whereas fast breeder reactors use sodium (liquid metal). In 2016, the decision was made to decommission Monju. As the first stage of decommissioning, the un- loading and handling of the fuel assembly*1, started in June 2017 and is scheduled to be completed in ap- proximately five and a half years, by December 2022 (see Fig. 2). The unloading and handling of the fuel as- sembly, including the two processing of fuel assembly Fig.1 Prototype fast breeder reactor Monju and the one unloading of the fuel assembly from the (Photo courtesy of the Japan Atomic Energy Agency)
1st stage 2nd stage Period for unloading and Preparation period 3rd stage 4th stage Stage handling of fuel assembly for dismantling ecommissioning period I ecommissioning period II Fiscal year 2018 to 2022 2023 to 2047
Unloading and handling of fuel assembly Preparations for dismantling sodium equipment ismantling and removal of sodium equipment Main implemen- Evaluation of the contamination distribution tation items ismantling and removal of power generation facilities such as water and steam systems ismantling and removal of buildings Processing and disposal of radioactive solid waste
Fig.2 Decommissioning schedule (Figure courtesy of the Japan Atomic Energy Agency) * 1: Unloading and handling of fuel assembly: A general term that corresponds to both the processing of the fuel assem- bly and unloading of the fuel assembly from the core. A fuel assembly is an assembly of nuclear fuel to be loaded * Power Generation Business Group, Fuji Electric Co., Ltd. into a nuclear reactor.
174 FY2018 FY FY2019 FY2020 FY2021 FY2022 (post-approval) Processing of fuel assembly Completion of unloading and handling of fuel assemblies Ex-vessel fuel storage tank → Spent fuel pool (530 assemblies) Unloading of fuel assembly from core Reactor vessel → Ex-vessel fuel storage tank (370 assemblies)
Facility inspection
Extraction of secondary Completion system sodium
Main 1st stage tasks and inspections Radiation survey and evaluation
Fig.3 First stage (period for unloading and handling of fuel assembly) schedule (Figure courtesy of the Japan Atomic Energy Agency) core, was performed by June 2020 on schedule using as quickly as possible as a top priority. the fuel handling facility system that Fuji Electric had It is planned that the processing of 530 fuel as- delivered (see Fig. 3). semblies and the unloading of 370 fuel assemblies from Fuji Electric collaborated with the reactor’s op- core will be completed in the first stage (until Decem- erator, Japan Atomic Energy Agency (JAEA), and ber 2022). As of June 2020, the processing of 260 fuel provided technical assistance such as dispatching en- assemblies and the unloading of 100 fuel assemblies gineers and overcame several problems that had not from core have been completed as scheduled. arisen before to complete the project. In this paper, we will provide an overview of the 3. Technology for Unloading and Handling of the operation and technologies required in the unloading Fuel Assembly and handling of the fuel assembly. Figure 4 shows the fuel handling and storage facili- 2. Monju situation ties for unloading and handling of the fuel assembly. Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s Figure 5 shows the transfer route for unloading and The decommissioning of Monju started with the handling the fuel assembly, and Table 1 shows the fuel assemblies remaining loaded in the shutdown re- operation process and respective facility. Several fa- actor. National and local governments demanded that cilities are rationally combined to share required func- the fuel assembly and sodium, which is a hazardous tions, such as fuel assembly grabbing and releasing, material that is highly reactive with water, be removed lifting and lowering, transferring, cooling, cleaning,
New fuel transfer machine Cask crane
Transport cask handling machine Ex-vessel fuel transfer system Spent fuel transfer machine
New fuel storage rack Fuel handling machine
Spent fuel storage rack In-vessel fuel transfer machine
Reactor vessel Spent fuel canning machine
Ex-vessel fuel storage tank Cask loading facility Under floor transfer car Under-water transfer car Spent fuel inspection system Spent fuel cleaning system
Fig.4 Fuel handling and storage facilities
Unloading and Handling Technology of the Fuel Assembly in Prototype Fast Breeder Reactor “Monju” 175 Spent fuel transfer Spent fuel canning Ex-vessel fuel machine machine storage tank
Ex-vessel fuel Fuel handling transfer system machine Rotating plug
Spent fuel pool
Under-water transfer car In-vessel fuel transfer machine Unloading of fuel assembly from core Reactor vessel Processing of fuel assembly Spent fuel water storage system Spent fuel cleaning system Sodium
Fig.5 Transfer route for unloading and handling of fuel assembly
Table 1 Process and facility used in the unloading and handling and then stored in the spent fuel storage rack in the of the fuel assembly spent fuel pool. Process Details Equipment used (1) Facility used Reactor fuel handling The following facilities of the fuel handling and Transfer of fuel as- machine system Unloading of sembly from the storage facilities (see Fig. 4) are used for the fuel as- Ex-vessel fuel transfer fuel assembly reactor vessel to the system sembly processing operation. from core ex-vessel fuel storage (a) Ex-vessel fuel transfer system (see Fig. 6) tank Ex-vessel fuel storage tank The ex-vessel fuel transfer system transfers the Ex-vessel fuel transfer fuel assembly between the reactor vessel and other system facilities, such as ex-vessel fuel storage tank. It is Ex-vessel fuel storage the main facility used in the fuel assembly process- The fuel assembly are tank temporarily stored Spent fuel cleaning ing operation. The ex-vessel fuel transfer system in the ex-vessel fuel system includes following two fuel handling machines: Ex- storage tank, trans- Spent fuel canning vessel fuel transfer machine A, which handles the Processing of ferred to the spent machine fuel assembly fuel cleaning system Under-water transfer sodium-adhered fuel assembly, and Ex-vessel fuel to clean (remove) the car, spent fuel transfer transfer machine B, which handles the sodium- adhered sodium, and machine and spent removed fuel assembly. then stored in the fuel storage rack spent fuel pool. Under floor transfer ◦Ex-vessel fuel transfer machine A car, new fuel transfer This machine handles fuel assembly in machine and new fuel sodium-filled environments or in sodium-mist storage rack
sealing, and shielding. Ex-vessel fuel transfer machine B Unloading and handling of the fuel assembly needs advanced technologies to remotely and safely handle Ex-vessel fuel transfer machine A fuel assembly stored in sodium or water. In particular, the fuel assembly soaked in sodium is invisible because Ex-vessel Gripper sodium is a liquid metal. fuel transfer Ex-vessel fuel transfer When sodium adheres to the fuel assembly, it re- machine car machine cooling system acts extremely easily with oxygen and water vapor in the air. Therefore, it is necessary to prevent contact with the air. Moreover, it has to be maintained above 100 °C to prevent solidification (coagulation). These challenges have made it difficult to handle the fuel as- sembly.
3.1 Processing of the fuel assembly During the processing of the fuel assembly, the Fuel transfer pot or fuel assembly fuel assembly that has temporarily stored in the ex- Overall view vessel fuel storage tank is transferred to the spent fuel cleaning system to clean (remove) the adhered sodium Fig.6 Ex-vessel fuel transfer system
176 FUJI ELECTRIC REVIEW vol.66 no.3 2020 atmospheres in which sodium metal particles will remotely and automatically operate this facility. are dispersed in the argon gas. The inside of its (a) The ex-vessel fuel storage tank holds liquid so- machine is hermetically sealed and filled with dium at approximately 200 °C. The spent fuel argon gas. assembly is removed from this storage tank, ◦Ex-vessel fuel transfer machine B cleaned, water canned, and stored on spent fuel This machine handles fuel assembly in storage rack. water-filled environments or in humid - atmo (b) The dummy assembly is removed from the new spheres. The inside of its machine is hermeti- fuel storage rack and then stored at the same cally sealed and filled with air. location of the ex-vessel fuel storage tank where ◦Ex-vessel fuel transfer machine cooling system the removed fuel assembly was stored. Before This system, consists of equipment and pip- loading into the ex-vessel fuel storage tank, the ing that supplies and discharges (circulates) fuel assembly is preheated to reduce the tem- cooling gas, removes the heat generated from perature difference with sodium. the spent fuel assembly stored in the ex-vessel In order to shorten the total operating time while fuel transfer machine. Two types are available ensuring safety in handling each fuel assembly and designed for the machine A and machine B. dummy assembly, the operation program is designed to ◦Ex-vessel fuel transfer machine car subdivide processes (a) and (b) and combine sequential This car travels with the machine A, ma- and parallel operations appropriately. chine B and cooling system mounted so that (3) Results of fuel assembly processing they can be precisely positioned on the respec- (a) 1st: August 2018 to January 2019 tive piece of facility. The goal was to process 100 fuel assemblies. (b) Ex-vessel fuel storage tank However, due to several issues that we had not This facility is used for intermediate storage of undergone yet, described in Section 4, we only fuel assemblies and radioactive-decay-awaiting stor- processed 86 fuel assemblies and transferred 86 age of spent fuel assemblies in the sodium tank. dummy assemblies. (c) Spent fuel cleaning system (b) 2nd: February 2020 to June 2020 This system cleans (removes) sodium from spent The goal was to process 130 fuel assemblies. We fuel assembly with steam and water. This system effectively utilized the corresponding countermea- prevents rapid reaction of sodium and water by first sures based on the experience of our first attempt supplying steam and then allowing sodium and wa- to process 174 fuel assemblies and transfer 140 ter to gradually react. dummy assemblies. (d) Spent fuel canning machine Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s This machine performs water canning of fuel as- 3.2 Unloading of fuel assembly from core sembly after cleaning. Water canning refers to the The fuel assembly is unloaded from the reactor encapsulation of fuel assemblies with water in a can (core) and loaded (temporarily stored) in the ex-vessel using the spent fuel canning machine. fuel storage tank. Dummy assembly is then loaded at (e) Under-water transfer car, spent fuel transfer the core position where the fuel assembly was loaded. machine and spent fuel storage rack (1) Facility used They are used for receiving spent fuel assem- The following facilities of the fuel handling and bly, which is non-encapsulated or water-canned, storage facilities (see Fig. 4) are used during the pro- from ex-vessel fuel transfer system and storing cess of unloading the fuel assembly from the core. it in water in preparation for storage off- (a) Reactor fuel handling machine system premises. This system consists of the following facilities (f) Under floor transfer car, new fuel transfer- ma that transfer fuel assembly in sodium inside the re- chine and new fuel storage rack actor vessel. They are for receiving dummy assembly (dum- ◦Fuel handling machine mied external shape of fuel assembly) and the can This machine inserts and removes fuel as- that has been carried in the premise for temporary sembly in and out of the core. storage in indoor air before the processing of the fuel ◦In-vessel fuel transfer machine assembly. This machine delivers fuel assembly be- During the processing of fuel assembly, these tween the fuel handling machine and ex-vessel facilities are used to deliver the dummy assembly or fuel transfer machine A. can to the ex-vessel fuel transfer system. (b) Ex-vessel fuel transfer system (see Fig. 6) (2) Overview of fuel assembly processing During the process of unloading the fuel as- An overview of the operation of the fuel assembly sembly from the core, it transfers the fuel assembly process for water canning is as follows. In order to between the reactor vessel (in-vessel fuel transfer ensure safety and allow multiple facilities to be com- machine) and ex-vessel fuel storage tank. bined, just pressing a blinked push button on the panel (c) Ex-vessel fuel storage tank
Unloading and Handling Technology of the Fuel Assembly in Prototype Fast Breeder Reactor “Monju” 177 (2) Overview of unloading fuel assembly from core fuel assembly. The torque at the time of opening The unloading of the fuel assembly from the core is and closing the gripper fingers was higher than the operated remotely and automatically in the same man- designed value. ner as fuel assembly processing. (b) Estimation of cause The spent fuel assembly is pulled out from the When visually checking the gripper, we found reactor (core), transferred, and stored in an ex-vessel that many sodium compounds were adhering to the fuel storage tank. The dummy assembly is unloaded surface of the gripper (see Fig. 9) and that these ad- from the ex-vessel fuel storage tank and transferred herents interfered with the opening and closing of and inserted at the same position of the core where the the fingers. When handling fuel assembly, sodium fuel assembly had been loaded. One fuel assembly or adhered to the gripper and stainless steel tape. This dummy assembly is processed at a time. To shorten adhered sodium converted into compounds such as the total operating time and ensure safety, the opera- sodium hydroxide and sodium oxide and solidified, tion program is designed to subdivide processes and causing the sliding parts to stick and the torque to combine sequential and parallel operations appropri- increase. ately. During the cleaning process of the spent fuel (3) Results of unloading of fuel assembly: September cleaning system, the water in the fuel cleaning tank 2019 to October 2019 is drained after the cleaning is completed. After We successfully unloaded 100 fuel assemblies and this, the inside of the fuel cleaning tank is dried so transferred 100 dummy assemblies just as planned. that it can receive the sodium-adhered fuel assem- bly from ex-vessel fuel transfer machine A. We sup- 4. Overcoming Challenges That Have Not Been posed that, when the machine A and the fuel clean- Experienced
The initial fuel assembly processing was the first Tape substantial operation of its kind. This resulted in vari- ous new kinds of challenges. We will now describe the major challenges we faced and corresponding measures we took. (1) Torque increase due to adhesion of sodium com- rum pounds (a) Overview of phenomenon Casing Ex-vessel fuel transfer machine A (see Fig. 7) grabs and releases fuel assembly by opening and closing the fingers of the gripper (see Fig. 8). Stain- less steel tape is wound in and out from the gripper Actuator rod drive unit at the top to grab, release, lift, and lower Finger
Gripper drive unit Fig.8 Ex-vessel fuel transfer machine A gripper
Gripper Sodium compound (adherend) Coffin
Fuel transfer pot
Movable block
oor valve
Fig.7 Ex-vessel fuel transfer machine A (Machine B basically has the same configuration.) Fig.9 Appearance of lower part of gripper
178 FUJI ELECTRIC REVIEW vol.66 no.3 2020 ing tank were connected and the drying process and We supposed that the sodium that had dripped gas replacement were insufficient, the gripper was on the valve entered the gap between the door valve exposed to a high dew point atmosphere or moisture and the casing and solidified into a compound such penetrated into the machine A, which resulted in as sodium hydroxide or sodium oxide, preventing the torque increase. the valve element from moving and the valve seat Therefore, we measured the dew point tempera- from sealing. The cause of the formation of the com- ture in the fuel cleaning tank and found that the pound was due to insufficient removal of moisture, drying process after cleaning was insufficient. We similar to the case of the increased torque during also discovered that the residual moisture due to opening and closing of the gripper fingers described insufficient drying in the fuel cleaning tank caused in the previous section. the compounding of the sodium that was adhered to (c) Implementing countermeasures the gripper. Similar to the previous section, we improved the (c) Implementing countermeasures drying process in the fuel cleaning tank. In order to improve the drying function in the (d) Effect of countermeasures fuel cleaning tank, we added heaters and heat in- During the second fuel assembly processing op- sulators to the fuel cleaning tank and surrounding eration, there was no door valve incomplete closure piping. We also lengthened the drying process time unlike our first attempt. We confirmed that the to the extent that the total operation time was not opening and closing of the door valve had stabilized. prolonged and increased the number of gas replace- ments. After taking these measures, we proceeded 5. Postscript with the second fuel assembly processing work. (d) Effect of countermeasures In this paper, we described the unloading and During the second fuel assembly processing handling technology used for the fuel assembly in the work, we initially observed the same abnormal prototype fast breeder reactor “Monju.” Fuji Electric increase in torque that we saw during our first -at collaborated in the unloading and handling of the fuel tempt, but the phenomenon thereafter disappeared assembly with the Japan Atomic Energy Agency, and and the torque stabilized. provided technical assistance throughout the project, The dew point temperature in the fuel cleaning such as dispatching engineers. This contributed to the tank also stabilized, decreasing to -60 °C or lower. completion of the operation, which included overcom- This indicated a definite improvement. ing some issues that had not been experienced before. (2) Door valve incomplete closure due to adhesion of We have also demonstrated our fuel assembly re- sodium compound moval technology during the fuel assembly handling Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s (a) Overview of phenomenon operation. We have obtained the actual operation data After the fuel assembly are stored in the ma- on the fuel handling facility system. We will continue chine, the door valve at the bottom of the unit is to collect this data in the future. Fuji Electric will fully closed in normal operation. However, the door evaluate actual operation data and reflect the results valve was not closed completely, causing seal leak- into the design of next-generation fast reactor facility, age at the valve seat. positively contributing the development of fast reactors (b) Estimation of cause that will pave the way for a low-carbon society.
Unloading and Handling Technology of the Fuel Assembly in Prototype Fast Breeder Reactor “Monju” 179 Radioactive Waste Treatment Using the Advanced “SIAL®” Solidification Technology SEKINE, Nobuyuki * MIKAMI, Hisashi * ONOZAKI, Kimihiro *
ABSTRACT
Geopolymer has been attracting attention as a solidifying agent for radioactive waste treatment because it is physically and chemically more stable than cement and provides better confinement of radionuclides and heavy met- als. Fuji Electric conducted the first demonstration test in Japan using the filter sludge and spent ion exchange resin disposed by nuclear power plants to facilitate the application of the geopolymer-based advanced solidification tech- nology“ SIAL®”. We confirmed that solidified products filled with radioactive waste up to 40 wt% had higher compres- sive strength than required for geological disposal. In addition, we confirmed that the partition coefficients of repre- sentative radionuclides sufficiently satisfied the configuration values for geological disposal facilities.
1. Introduction 2. “SIAL®” Features Nuclear power plants stably supply large amounts of electricity. However, they produce radioactive waste Geopolymers are a condensate of inorganic materi- including liquid waste, such as concentrated liquid als formed from aluminosilicates powder and alumino- waste, and solid waste, such as spent ion exchange silicates solution. SIAL® is uses metakaolin (SIAL-B) resin, during operation. In Japan, these types of ra- as alumina-silica powder and water glass (SIAL-A) as dioactive waste are stabilized and solidified in drums alkali-silica solution. It solidifies at room temperature using cement, asphalt, plastic, and other solidify- just like cement. Optimizing the composition of SIAL- ing agents, and then disposed of as landfill waste at A, SIAL-B, and various additives will allow SIAL® to the Rokkasho Low-Level Radioactive Waste Disposal have more superior ability than cement. SIAL® can Center of Japan Nuclear Fuel Limited in Rokkasho-mura, improve fill rate and directly solidify waste without Aomori Prefecture. requiring a pretreatment when in stabilizing and so- Although cement is becoming the mainstream lidifying concentrated liquid waste that contains high solidifying agent for radioactive waste, geopolymers, concentrations of sulfate, borate, and other inorganic which are inorganic materials like cement, have been salts, ion exchange resins that contain organic matter, attracting attention in recent years as a new type of incinerator ash, and oils. solidifying agent. Geopolymers are physically and chemically more stable than cement and are character- 3. “SIAL®” Basic Performance Capabilities ized by their high ability to confine radionuclides and heavy metals. 3.1 Comparison with cement Outside Japan, AllDeco Ltd. (currently, Jacobs In order to understand the basic performance capa- Engineering Group Inc.) developed an advanced bilities of SIAL®, we used cold testing*2 to evaluate the ® 1 3 “SIAL * ” solidification technology using geopolymers. partition coefficients* Kd of cobalt (Co), strontium (Sr), This technology was licensed by the Nuclear Regulatory and cesium (Cs). We then compared its performance Authority of the Slovak Republic (UJD SR) in 2003 and with cement. Table 1 shows the comparison of parti- the State Office for Nuclear Safety (SUJB) of the Czech tion coefficients between cement and ® SIAL composed Republic in 2006 to be utilized for the first time in the of SIAL-A and SIAL-B. Compared with cement, con- world in radioactive waste treatment. Fuji Electric finement of Sr and Cs was higher. Although that of Co has been developing a technology to use Jacobs was lower, but it was proved to have sufficient confine- Engineering Group’s SIAL® for radioactive waste treat- ment in Japan. In this paper, we will describe the fea- *2 Cold testing: A preliminary or simulated test conducted tures of the technology and the demonstration tests. without radiation or radioactive materials. *3 The partition coefficient: An indicator of characteristics in *1 SIAL: A registered trademark of Jacobs Slovakia s.r.o. a partitioning equilibrium model. It represents the con- finement of elements such as radionuclides. The higher the value, the higher the confinement. * Power Generation Business Group, Fuji Electric Co., Ltd.
180 Table 1 Comparison of partition coefficients Initial concentra- tion: 100 ppm 60
Partition coefficient (m3/kg) Fill rate 10 wt% Element Co Sr Cs Fill rate 40 wt% SIAL® solidified 0.28 0.95 0.55 40 Required compressive strength for body disposal: 1.5 MPa Cement solidified 37 0.004 0.0003 body
20 ment as basic properties. Compressive strength (MPa)
Kd = (V/Ws)・(C0 - Ci)/Ci 0 Carbonate Metaborate Sulfate 3 Kd : Partition coefficient (m /kg) C : Initial solution element concentration (ppm) 0 Fig.2 Comparison of compressive strength Ci : End-of-reaction solution element concentra- tion (ppm) the reference standard when unfilled, carbonate accel- V : Solution volume (m3) erated the curing process, whereas metaborate delayed W : Solidified body mass (kg) s it. Sulfate worked to slightly accelerate solidification. For sulfate, the data is shown only during the first two 3.2 Solidification of inorganic salts hours because the viscosity exceeded the upper limit of We conducted solidification tests with the basic measurement after the time. These results suggested compound composition of SIAL® to investigate how that the effect of inorganic salts on the solidification geopolymer solidification is affected by inorganic salts of geopolymer tended to be similar to that on conven- such as carbonate, borate, and sulfate, which can be tional cement. We also evaluated the compressive present in radioactive waste. strength of solidified bodies filled with inorganic salts. First, we checked the time variation of the viscos- They were solidified at a fill rate of up to 40 wt%. As ity after kneading geopolymer. Table 2 shows the ini- shown in Fig. 2, the compressive strength reached tial viscosity immediately after kneading geopolymer. 32 MPa when filled with carbonate, 9 MPa with metab- The initial viscosity increased as the inorganic salt orate, and 10 MPa with sulfate, all exceeding 1.5 MPa, fill rate increased. Figure 1 shows the time variation which is the required compressive strength for dis- of the magnification ratio of the viscosity rate based posal. We thus confirmed that the inorganic salts had Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s on the initial viscosity at an inorganic salt fill rate of sufficient strength. We plan to optimize the fill rate 10 wt%. Compared with viscosity increase variation as and compound composition when the commercial oper- ation starts for solidifying radioactive waste including Table 2 Comparison of initial viscosity those inorganic salts using SIAL®. Inorganic salt fill rate (wt%) 0 10 40 Carbonate 5 10 4. Radioactive Waste Treatment Demonstration Initial viscosity Metaborate 3 9 10 Test (Pa s) ・ Sulfate 21 23 SIAL® has been commercialized for radioactive waste treatment outside Japan, but since Japanese evaluation criteria are different, it was necessary to 10 perform demonstration tests using radioactive waste produced by a nuclear power plant in Japan. In coop- 8 eration with Japan Atomic Power Company, we con- Unfilled Carbonate ducted demonstration tests using radioactive waste 6 produced by the Tsuruga Nuclear Power Plant in ac- cordance with Japanese standards. 4 Sulfate Metaborate The radioactive waste used during the test in- cluded filter sludge (FS) and spent ion exchange resin 2 (SR). Filters precoated with filter aid are used in nu-
Viscosity rate of increase (factor) clear reactor purification systems. FS is a sludge-like 0 0 1 2 3 4 5 radioactive waste containing filter aid and iron rust Time (h) produced during filter cleaning. SR is the radioactive waste of ion exchange resin used to remove ionic im- Fig.1 Comparison of viscosity rate of increase purities from liquids. These types of radioactive waste (fill rate of 10 wt%) contain a variety of radionuclides.
Radioactive Waste Treatment Using the Advanced “SIAL®” Solidification Technology 181 cellulose contained in FS, has been reported to signifi- 4.1 Optimization of compound composition in cold testing cantly increase the solubility of alpha-nuclides*5 such In order to solidify radioactive waste, it is neces- as plutonium. We were concerned that this could re- sary to optimize the compound composition of the so- duce the partition coefficient, making radionuclides lidifying agent for each type of radioactive waste. We more soluble. Therefore, we investigated the effect of performed cold testing beforehand using simulated FS-containing ISA on the partition coefficient. We also radioactive waste samples. By optimizing the com- investigated SR because there was a concern that ISA pound composition of SIAL® for each simulated FS and eluted after landfill burying could affect SR. SR sample, we solidified samples at a fill rate up to 40 wt%, achieving the required compressive strength of 4.3 Demonstration testing method in hot testing 1.5 MPa or higher. (1) Radioactive waste solidification We solidified radioactive waste using ® SIAL with 4.2 Demonstration of SIAL® in hot testing the compound composition optimized by cold testing. For one of the demonstration tests, we performed We set the fill rate of radioactive waste to 40 wt%, hot testing*4 of geopolymers compounded with SIAL®. which was the same as that used during cold testing. The composition was determined during cold testing us- After kneading SIAL® with the radioactive waste, we ing the radioactive waste shown in Table 3 and Fig. 3. evaluated the solidified product after 28 days of curing. Isosaccharinic acid (ISA), a decomposition product of (2) Compressive strength We measured the unconfined compressive strength Table 3 Types of radioactive wastes used in hot testing of the solidified bodies. Surface dose equivalent Moisture content (3) Partition coefficient measurement testing rate (mSv/h) (%) We evaluated the partition coefficient for repre- FS 0.27 74 to 75 sentative radionuclides. Table 4 shows the partition SR 0.50 to 0.60 52 to 55 coefficient measurement conditions. We set the initial concentration of ISA to 10 mM (M = mol/L), which was excessive for the nuclide concentrations and the sorp- tion to the solidifying agent and waste, to secure safety margin.
4.4 Results and evaluation (1) Uniformity and compressive strength Figure 4 shows the cross-sectional photographs of the solidified radioactive waste. We confirmed that the solidified bodies for both FS and SR solidified uni- formly. As shown in Table 5, the compressive strength was 14 MPa for the FS solidified body and 7.7 MPa for the SR solidified body. Both of them had a sufficient
(a) Filter sludge (FS) compressive strength of more than 1.5 MPa, which is the required strength for landfill burying. (2) Partition coefficient results Figure 5 shows the partition coefficients for the FS and SR solidified bodies. The partition coefficients of representative radionuclides sufficiently satisfied the configuration values of the No. 3 Waste Disposal Facility at the Rokkasho Low-Level Radioactive Waste Disposal Center. As shown in Table 6, the effect on ISA partition coefficients showed that the partition
Table 4 Partition coefficient measurement conditions Item Condition (b) Spent ion exchange resin (SR) FS solidified body, SR solidified body Sample Shape: Granular (0.5 to 5 mm) Fig.3 Appearance of radioactive waste Test solution Equilibrium water Solid-liquid ratio Solid/liquid = 1/10 *4 Hot test: A test that uses radiation or radioactive materi- ISA initial concentration Without ISA, 10 mM als. Testing time 168 hours *5 Alpha nuclide: Radionuclide that emits alpha rays (He Testing environment Nitrogen atmosphere nuclei) during nuclear fission.
182 FUJI ELECTRIC REVIEW vol.66 no.3 2020 Without ISA With ISA Configuration value
10 /kg) 3 1
0.1
0.01 Partition coefficient (m (a) Filter sludge (FS) solidified body 0.001 60Co 63Ni 90Sr 137Cs All-alpha (a) FS solidified body
10 /kg) 3 1
0.1
0.01 Partition coefficient (m 0.001 60 63 90 137 (b) Spent ion exchange resin (SR) solidified body Co Ni Sr Cs All-alpha (b) SR solidified body Fig.4 Cross-sectional photographs of solidified body (dimen- sions φ50 × 100 mm) Fig.5 Partition coefficient of major nuclides
Table 5 Surface dose equivalent rate and compressive strength Table 6 ISA impact assessment results of solidified bodies Partition coefficient rate of increase (factor) issue: Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society issue: Fuji Electric’s Surface dose equivalent Compressive strength 60 63 90 137 rate (mSv/h) (MPa) Co Ni Sr Cs All-alpha FS solidified FS solidi- 0.12 14 1.0 1.0 1.3 1.0 1.0 body fied body SR solidified SR solidi- 0.08 7.7 0.9 1.2 0.6 1.0 0.5 body fied body
5. Postscript coefficients of 90Sr and all-alpha (all nuclides emit- ting alpha-rays) decreased slightly in the SR solidified In this paper, we described radioactive waste body, but all of the nuclides performed better than the treatment using the advanced “SIAL®” solidification partition coefficient configuration values at the No.3 technology. Geopolymers have a track record of use Waste Disposal Facility. We verified that there was no outside Japan. However, in Japan, it is necessary to significant impact for all-alpha, which was our greatest reasonably show that their use provides medium- to concern with respect to ISA. long-term stability. In the future, we intend to con- duct a full-scale demonstration test using real-life 200- liter drums and then evaluate long-term performance changes.
We conducted the demonstration test for radioac- tive waste treatment in cooperation with the Japan Atomic Power Company and Jacobs Engineering Group Inc. (Critical Mission Solutions International). We would like to conclude by expressing our apprecia- tion to all those involved in this project.
Radioactive Waste Treatment Using the Advanced “SIAL®” Solidification Technology 183 “Wiserot” LAN-Connected Diagnostic System for Rotating Machine Vibration SAISHO, Toshiharu *
When a motor, fan, pump, blower, or other piece (a) Supports large-volume data transmission, en- of machinery suddenly breaks down on a production abling data transmission up to 262,144 points line, it can take from several hours to several days to instead of the 4,096 points supported by con- recover, resulting in enormous fi nancial losses due to ventional types. This has greatly improved the production stoppages during the downtime. In order resolution of fast Fourier transformation (FFT) to prevent these types of sudden failures, measures frequency analysis from 6.25 Hz to 0.09 Hz, al- are increasingly being taken to perform preventive maintenance to monitor motors and other machinery for abnormal vibration. Furthermore, in recent years, companies have been increasingly adopting Internet of Things (IoT) technology into their maintenance opera- tions as a key policy. This has expanded the applica- tion of initiatives for measuring vibration. However, when companies endeavor to incorporate vibration measurement initiatives into their maintenance tasks, maintenance personnel often fi nd it very diffi cult to es- tablish threshold values to use as judgment standard values for caution and danger states. Therefore, many companies have been hesitant to adopt actual mea- sures. The “Wiserot” diagnostic system for rotating machine vibration utilizes the expertise cultivated by Fuji Electric as a manufacturer of rotating machinery to provide solutions that enable operators to effec- Fig.1 LAN-connected vibration sensor tively troubleshoot problems. Recently, Fuji Electric has launched a LAN-connected Wiserot system that can process large amounts of data to meet the need of On-site system Cloud-based system precise diagnosis at higher resolutions than ever. It PC PC can be used in conjunction with conventional wireless ata Wiserot systems. collection Customer office Cloud service Customer office 1. LAN-Connected Wiserot Analysis and Analysis and diagnosis software diagnosis software Simple diagnosis FFT analysis function and FFT functions and simple The conventional wireless Wiserot system is de- diagnosis functions signed to ease installation work and provided with a analysis function are provided as cloud services. battery and 314-MHz specifi c low power wireless con- nection to build complete wireless system. However, HUB they are not suitable for transmitting a suffi cient amount of data to accurately identify locations of fail- VPN router ure. Recently, we have released a LAN-connected vi- LAN-connected bration sensor that uses wired communications and vibration sensor FiTSAΣ continuous power feeding (an AC adapter) to transmit Sensors Sensors a large amount of data. It can be operated in conjunc- tion with wireless types depending on the installation site and other circumstances. Figure 1 shows the ex- ternal appearance of a LAN-connected vibration sensor Inverter Motor Equipment using and Fig. 2 shows a system confi guration. various types of bearings (fans, pumps, intermediate bearings, etc.)
* Power Electronics Systems Industry Business Group, Fuji Electric Co., Ltd. Fig.2 LAN-connected Wiserot system confi guration
184 2020-S04-1 FUJI ELECTRIC REVIEW vol.66 no.3 2020 lowing precise diagnosis and accurate identifica- sign. When the status changes to caution or danger, tion of locations of bearing failure. operators can check failure signs on the monitoring (b) Uses Ethernet*1 communication to eliminate the screen for each piece of equipment. need for conventional wireless repeaters (LAN (2) Trend monitoring adapters, transceivers). This makes it possible Trend graphs of machine vibration, bearing vibra- to build a simple system, while eliminating the tion and temperature is designed to monitor medium- need for specialized wireless environment sur- and long-term trends. This allows operators absolute veys during field installation work. and relative judgment by identifying the status (nor- mal, caution or danger) with threshold values. 2. Overview of “Wiserot” (3) Cause analysis with FFT frequency analysis FFT frequency analysis is used to drill down on The Wiserot monitors motors and mechanical causes of failure after finding out failure signs in trend equipment for signs of failure by measuring mechani- graphs. Frequency analysis of mechanical vibration cal vibration and bearing vibration of them while identifies mechanical failures such as imbalance and switching signal frequency bands. misalignment. Frequency analysis of bearing vibration
Our previously released wireless Wiserot system identifies bearing failures, such as grease depletion, in- New Products (see Fig. 3) has been introduced in various industrial ner ring damage and outer ring damage, as well as to fields, such as steel, chemical, automobile, food and determine locations of failure. beverage fields. To meet many needs from Japanese As shown in Fig. 2, the Wiserot systems are avail- companies abroad, it has obtained certifications for able in on-site and cloud-based systems. wireless network not only in Japan, but also in the EU, India, Southeast Asia, Taiwan and China. Our recently 3. Diagnostic judgment method released LAN-connected Wiserot has the following functions same as the wireless type. Mechanical vibration and bearing vibration are (1) Comprehensive monitoring of equipment measured using the bands shown in Table 1. The summary screen displays equipment status (1) Mechanical vibration judgment (low-frequency vi- (i.e., normal, caution or danger) for monitoring failure bration) For mechanical vibration caused by imbalance and misalignment, the system comes with absolute judg- ment standard data in accordance with JIS B0906, which is a general guideline for measuring and evalu- ating mechanical vibration. With the data, It deter- mines a status of normal, caution or danger depending on the rated capacity of the rotating machine. The sys- tem also enables operators to set a relative judgment standard value according to the inherent conditions of (a) Transceiver the customer’s equipment, such as the rigidity of the (c) LAN adapter installation location. This facilitates finely-tuned -op eration based on the equipment and installation envi- ronment. (b) Wireless vibration sensors (2) Bearing vibration judgment (high-frequency vibra- tion) Fig.3 Wireless "Wiserot" Conventionally, it has been difficult for company
Table 1 Diagnostic items and judgment standard Measurement Diagnostic item Vibration type Judgment item Judgment standard bandwidth Absolute judgment based on the vibration Velocity (mm/s) Root mean square evaluation standard (JIS B0906) Low frequency Mechanical vibration Overall, (10 to 250 Hz) Displacement Rotational speed component (n), Relative judgment (µm) electromagnetic component (2f) Root mean square Relative judgment High frequency Bearing vibration Acceleration (G) (1 to 10 kHz) Q value (bearing diagnosis judg- Absolute judgment of rolling bearings based ment value) on Fuji Electric’s own standards * The threshold value settings can be changed by users in accordance with the various site conditions.
*1 Ethernet is a trademark or registered trademark of Fuji Xerox Co., Ltd.
“Wiserot” LAN-Connected Diagnostic System for Rotating Machine Vibration 185 personnel to establish threshold values that can be The Wiserot uses unique filtering technology to used as judgment standard for abnormal bearing vi- remove carrier vibration noise and measure only the bration due to bearing damage or grease depletion. inherent vibration of the bearings to ensure accurate However, the Wiserot comes with absolute judgment judgments. standard Q values that Fuji Electric, a rotating ma- chine manufacturer, has uniquely established. Using Start of order acceptance the judgment standard Q values makes it easy for op- Japan: April 2020 erators to establish threshold values, because thresh- Abroad: Scheduled from FY2022 old values are automatically adjusted by simply input- ting the bearing type and rotation speed of the equip- ment to be monitored. Product Inquiries (3) Removal of Inverter carrier vibration noise Fuji Electric Co., Ltd. In inverter-driven rotating machines, carrier vibra- Business Planning Department, Field Services Divi- tion noise is superimposed in regions of high-frequency sion, Power Electronics Systems Industry Business vibration. Therefore, when monitoring bearing condi- Group, Fuji Electric Co., Ltd. tion by measuring high-frequency vibration, the sys- Phone: +81-3-5435-7278 tem can make a misjudgment due to superimposed car- rier vibration noise on the inherent bearing vibration. This means that bearing vibration that is typically judged as normal may be misjudged as danger.
186 2020-S04-3 FUJI ELECTRIC REVIEW vol.66 no.3 2020 Muara Laboh Geothermal Power Plant
FE’s steam turbine/generator C S C S S
Indonesia boasts the world’s second largest reserve of geothermal Laboh (SEML), an independent power producer, reacted favorably resources. In the mountains of western Sumatra, located about fi ve to these past results of adoption, which led to our landing the order. hours by car from the nearest airport is Muara Laboh Geothermal This was SEML’s fi rst geothermal power generation project, and Power Plant (generation capacity: 85.26 MW), which began com- they were fi rmly committed to making it a success. For this reason, mercial operation in December 2019. The power it generates, equiv- there were higher demands for specifi cations, quality, and safety as alent to the power usage of about 420,000 Indonesian households, compared with our other past geothermal power generation projects is supplied to all of western Sumatra. The consortium of Sumitomo in Indonesia. After continuously meeting these demands, we earned Corporation and PT. Rekayasa Industri, a major local engineering recognition from SEML and were able to build a good relationship. company, undertook the power plant construction as a turnkey EPC This brought us together as a team in undertaking this project, and (engineering, procurement, and construction) project. FE was in we were able to successfully complete construction by the delivery charge of engineering for the entire plant and procurement of major date. equipment under Sumitomo Corporation. We delivered steam tur- “I am very happy to have been able to contribute to the develop- bines and generators manufactured by the Kawasaki Factory as well ment of Indonesia,” says salesperson Mei Hondo with delight and as motors and TGRs* manufactured by the Suzuka Factory. ambition. “We want to continue to contribute to creating a safe, se- In geothermal power generation, the power of steam from the cure, and sustainable society not just through geothermal power gen- ground is used to rotate the turbine and generator for power genera- eration but by expanding our renewable energy business as a whole.” tion. It does not use fossil fuel or emit CO2. For this reason, geother- Integrated digital control system for turbines and generators mal power plants are becoming popular around the world as envi- ronmental awareness increases amidst global warming. Indonesia has been recently showing rapid economic growth, and there are still some areas without access to electricity. The government aims to put a power infrastructure in place and is planning to increase the total capacity of geothermal power generation from approximately 2,000 MW in 2019 to 7,200 MW by 2025. Having already delivered many geothermal power systems, FE leads the market for steam turbines for geothermal power genera- tion with a global market share of 40% (deliveries between 2000 and 2019). In Indonesia specifi cally, we have delivered 19 steam turbines for geothermal power generation and boast a market share of 50% Project members from SEML and Sumitomo Corporation and FE’s persons in charge (as of January 2019). The end customer, PT. Supreme Energy Muara Fe-Products Found in Society A S S A
Kobe Hokuto Hospital
A mask vending machine in a hospital
Spiral rack-type storage shelves
With the spread of the new coronavirus, it’s becoming more We have already received inquiries from the public transportation common to see people wearing a mask while out and about. and retail industries. Shinichi Takeoka, an FE sales representative, Given the need to adapt and live with the coronavirus, FE has expresses his future hopes, saying, “The product’s strength lies in developed a special vending machine that can dispense sanitary its versatility, or the capability of holding a variety of items. We aim products such as masks. On June 22, we installed the fi rst unit in to popularize mask vending machines by leveraging their value to Kobe Hokuto Hospital. the customer: the ability to reduce interpersonal contact while “In the past, we sold masks at the reception desk. But we didn’t still providing items safely and securely.” have enough staff for that purpose during peak times, so we needed to rethink how we would do it,” says President Horikoshi of HG Corporation, which manages the hospital’s welfare supplies Example of SDGs and sales facilities. Our mask vending machine can sell not only masks but a variety of other items that inpatients may need, such ● Goal 11 as slippers and toothbrushes. It also meets the customer’s needs Sustainable cities and communities because it can mitigate labor shortages and function as a small By developing and popularizing mask vending unmanned store. machines, we aim to create an environment We are the leader of the domestic beverage vending machine where people can easily obtain sanitary goods industry, with a market share of over 50%. We have been contribut- to contribute to preventing the spread of infectious diseases and achieving safe and secure lives. ing to solving social issues such as labor shortages by, for example, proposing nighttime unmanned operations using vending machines in convenience stores. “Masks are essential for our daily lives, so they need to be available anytime and anywhere. We had to think of a new way to contribute to society in this age of living with the coro- navirus,” says Daisuke Sato, Product Planning Department. The mask vending machine is an improvement on an existing multipurpose vending machine. The buttons, return lever, and ar- ticle outlet have undergone antimicrobial treatment to improve hy- giene. The storage shelves feature a spiral rack system that allows users to adjust the pitch (spacing) to freely change the size and the number of items on display. To prevent product deterioration in a high-temperature environment, we also offer a model with temper- Two people are from Sales Department IV, Kansai Area Operation and ature settings that can maintain an internal temperature of 18°C so Product Planning Department, Sales Division, Food & Beverage Distri- that cooled masks can be sold in the summer. bution Business Group, Fuji Electric. 最終校正 Fuji Electric Korea Co., Ltd. Overseas Subsidiaries Sales of power distribution and control equipment, drive control equipment, rotators, high-voltage inverters, electronic control panels, medium- and large-sized Non-consolidated subsidiaries * UPS, and measurement equipment Tel +82-2-780-5011 America URL http://www.fujielectric.co.kr/ Fuji Electric Corp. of America Fuji Electric Co.,Ltd. (Middle East Branch Offi ce) Sales of electrical machinery and equipment, semiconductor devices, drive control Promotion of electrical products for the electrical utilities and the industrial plants equipment, and devices Tel +973-17 564 569 Tel +1-732-560-9410 URL https://americas.fujielectric.com/ Fuji Electric Co., Ltd. (Myanmar Branch Offi ce) Providing research, feasibility studies, Liaison services Reliable Turbine Services LLC Tel +95-1-382714 Repair and maintenance of steam turbines, generators, and peripheral equipment Tel +1-573-468-4045 Representative offi ce of Fujielectric Co., Ltd. (Cambodia) Providing research, feasibility studies, Liaison services Fuji SEMEC Inc. Tel +855-(0)23-964-070 2020 Manufacture and sales of door opening and closing systems Fuji Electric’s Power Generation Business to Realize Tel +1-450-641-4811 ■Equity-method Affi liates Vol.66 No. a Low-Carbon Society Fuji Furukawa E&C (Thailand) Co., Ltd. 3 Asia Design and installation contracting for electric facilities construction Tel +66-2-308-2703 Fuji Electric Asia Pacifi c Pte. Ltd. Since the enactment of the Paris Agreement, an international frame- Sales of electrical distribution and control equipment, drive control equipment, and Europe semiconductor devices work for mitigating climate change, countries around the world have Tel +65-6533-0014 Fuji Electric Europe GmbH been taking measures to accelerate decarbonization. As a result, the mar- URL http://www.sg.fujielectric.com/ Sales of electrical/electronic machinery and components Tel +49-69-6690290 Fuji SMBE Pte. Ltd. URL https://www.fujielectric-europe.com/ ket for renewable energy sources, which do not emit greenhouse gases, Manufacture, sales, and services relating to low-voltage power distribution has been expanding globally. In Japan, in addition to eff orts to achieve board(switchgear, control equipment) Fuji Electric France S.A.S Tel +65-6756-0988 Manufacture and sales of measurement and control devices the energy mix outlined in the Strategic Energy Plan, the government URL http://smbe.fujielectric.com/ Tel +33-4-73-98-26-98 URL https://www.fujielectric.fr/en established the Act of Establishing Energy Supply Resilience in June Fuji Electric (Thailand) Co., Ltd. Sales and engineering of electric substation equipment, control panels, and other Fuji N2telligence GmbH * 2 0 2 0 as an initiative to strengthen and improve the sustainability of electric equipment Sales and engineering of fuel cells and peripheral equipment Tel +66-2-210-0615 Tel +49 (0) 3841 758 4500 electricity supply systems. URL http://www.th.fujielectric.com/en/ China This special issue highlights Fuji Electric’s work toward establish- Fuji Electric Manufacturing (Thailand) Co., Ltd. Manufacture and sales of inverters (LV/MV), power systems (UPS, PCS, switching Fuji Electric (China) Co., Ltd. ing resilient and sustainable electricity supply systems and realizing a power supply systems), electric substation equipment (GIS) and vending machines Sales of locally manufactured or imported products in China, and export of locally Tel +66-2-5292178 low-carbon society by introducing the latest topics and technologies in manufactured products Fuji Tusco Co., Ltd. Tel +86-21-5496-1177 the fi eld of power generation. Manufacture and sales of Power Transformers, Distribution Transformers and Cast URL http://www.fujielectric.com.cn/ Resin Transformers Shanghai Electric Fuji Electric Power Technology Tel +66-2324-0100 (Wuxi) Co., Ltd. URL http://www.ftu.fujielectric.com/ Research and development for, design and manufacture of , and provision of Fuji Electric Vietnam Co.,Ltd. * consulting and services for electric drive products, equipment for industrial Sales of electrical distribution and control equipment and drive control equipment automation control systems, control facilities for wind power generation and Tel +84-24-3935-1593 photovoltaic power generation, uninterruptible power systems, and power electron- URL http://www.vn.fujielectric.com/en/ ics products Tel +86-510-8815-9229 Fuji Furukawa E&C (Vietnam) Co., Ltd. * Engineering and construction of mechanics and electrical works Wuxi Fuji Electric FA Co., Ltd. Tel +84-4-3755-5067 Manufacture and sales of low/high-voltage inverters, temperature controllers, gas analyzers, and UPS Fuji CAC Joint Stock Company Tel +86-510-8815-2088 Provide the Solution for Electrical and Process Control System Tel +84-28-3742-0959 Fuji Electric (Changshu) Co., Ltd. URL www.fujicac.com Manufacture and sales of electromagnetic contactors and thermal relays Tel +86-512-5284-5642 PT. Fuji Electric Indonesia URL http://www.csfe.com.cn/ Sales of inverters, servos, UPS, tools, and other component products Tel +62 21 574-4571 Fuji Electric (Zhuhai) Co., Ltd. URL http://www.id.fujielectric.com/ Manufacture and sales of industrial electric heating devices Tel +86-756-7267-861 P.T. Fuji Metec Semarang URL http://www.fujielectric.com.cn/fez/ Manufacture and sales of vending machines and their parts Tel +62-24-3520435 Fuji Electric (Shenzhen) Co., Ltd. URL http://www.fms.fujielectric.com/ Manufacture and sales of photoconductors, semiconductor devices and currency handling equipment Fuji Electric India Pvt. Ltd. Tel +86-755-2734-2910 Sales of drive control equipment and semiconductor devices URL http://www.szfujielectric.com.cn/ Tel +91-22-4010 4870 URL http://www.fujielectric.co.in Fuji Electric Dalian Co., Ltd. Manufacture of low-voltage circuit breakers Fuji Electric Consul Neowatt Private Limited Tel +86-411-8762-2000 Development, manufacuture, engineering, sales and servicing of UPS, Stabilizers, Active Harmonic Filters and other component products Fuji Electric Motor (Dalian) Co., Ltd. Tel +91-44-4000-4200 Manufacture of industrial motors URL https://www.india.fujielectric.com/ Tel +86-411-8763-6555 Fuji Gemco Private Limited Dailan Fuji Bingshan Vending Machine Co.,Ltd. Cover Photo: Design, manufacture, sales, and engineering for drive control systems Development, manufacture, sales, servicing, overhauling, and installation of Muara Laboh Geothermal Power Plant in Indonesia FUJI ELECTRIC REVIEW vol.66 no.3 2020 Tel +91-129-2274831 vending machines, and related consulting Tel +86-411-8754-5798 (Photo courtesy: PT, SEML) date of issue: September 30, 2020 Fuji Electric Philippines, Inc. Manufacture of semiconductor devices Dalian Fuji Bingshan Smart Control Systems Co., Ltd. Tel +63-2-844-6183 Energy management systems, distribution systems, and related system engineer- editor-in-chief and publisher KONDO Shiro ing Corporate R & D Headquarters Fuji Electric Sales Philippines Inc. Tel +86-411-8796-8340 Sales of energy management systems, process automation systems, factory Fuji Electric Co., Ltd. automation systems, power supply and facility systems, and power generation Fuji Electric (Hangzhou) Software Co., Ltd. Gate City Ohsaki, East Tower, Tel +63-2-541-8321 Development of vending machine-related control software and development of URL https://www.ph.fujielectric.com/ management software 11-2, Osaki 1-chome, Shinagawa-ku, Tel +86-571-8821-1661 Tokyo 141-0032, Japan Fuji Electric (Malaysia) Sdn. Bhd. URL http://www.fujielectric.com.cn/fhs/ Manufacture of magnetic disk and aluminum substrate for magnetic disk https://www.fujielectric.co.jp Tel +60- 4- 403-1111 Fuji Electric FA (Asia) Co., Ltd. URL http://www.fujielectric.com.my/ Sales of electrical distribution and control equipment Tel +852-2311-8282 editorial offi ce Fuji Electric Journal Editorial Offi ce Fuji Electric Sales Malaysia Sdn. Bhd. c/o Fuji Offi ce & Life Service Co., Ltd. Sales of energy management systems, process automation systems, factory Fuji Electric Hong Kong Co., Ltd. 1, Fujimachi, Hino-shi, Tokyo 191-8502, automation systems, power supply and facility systems, and vending machines Sales of semiconductor devices and photoconductors Tel +60 (0) 3 2780 9980 Tel +852-2664-8699 Japan URL https://www.my.fujielectric.com/ URL http://www.hk.fujielectric.com/en/ Fuji Electric Co., Ltd. reserves all rights concerning the republication and publication after translation Fuji Furukawa E&C (Malaysia) Sdn. Bhd. * Hoei Hong Kong Co., Ltd. Sales of electrical/electronic components into other languages of articles appearing herein. Engineering and construction of mechanics and electrical works Tel +60-3-4297-5322 Tel +852-2369-8186 All brand names and product names in this journal might be trademarks or registered trademarks of URL http://www.hoei.com.hk/ their respective companies. Fuji Electric Taiwan Co., Ltd. The original Japanese version of this journal is“FUJI ELECTRIC JOURNAL” vol.93 no.3. Sales of semiconductor devices, electrical distribution and control equipment, and drive control equipment Tel +886-2-2511-1820 Whole Number 270, ISSN 0429-8284 最終校正 FUJI ELECTRIC REVIEW
2020 Vol.66 No. 3 Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society
Fuji Electric’s Power Generation Business to Realize a Low-Carbon Society Vol.66 No.3 2020
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