Geothermal District Heating in China - Lessons learned Kolbeinn Björgvinsson Verkís Reykjavik, Iceland www.verkis.com 1 – 3 October 2014 - Warsaw, Poland Verkís | Ofanleiti 2 | 103 Reykjavík | Iceland | +354 422 8000 | www.verkis.com | [email protected] AGENDA • About Verkis Consluting Engineers • Geothermal District heating in China – Lessons learned, 2005 – ongoing About Verkis Verkís - Consulting Engineers Provides comprehensive services in all fields of engineering and related disciplines RT-Rafagnatækni Fjarhitun Fjölhönnun Founded 1961 Founded 1962 Founded 1970 1932 ´40 ´50 ´60 ´70 ´80 ´90 2000 ´10 ´20 VST Rafteikning Almenna Founded 1932 Founded 1965 Founded 1971 Organisation chart Total staff 350 Energy division 100 Turnover (2013) 33 MUSD Offices and operation location Headquarters: Ofanleiti 2, Reykjavík - Iceland 8 branch offices in Iceland Greenland Norway Polland Ukraine Bulgaria Chile Offices and affiliates abroad Projects worldwide Energy – Fields of expertise Geothermal power District heating Geothermal utilization Consulting services - at all project stages Distribution Hydropower Power transmission Other renewables We cover all aspects of geothermal utilization Generation of electricity • Steam turbines • Binary plants • District heating • More than 1.000 MWt since 1950 • Integrated utilization • Cogeneration of heat and power • Cascaded use of geothermal water Geothermal District Heating Reykjavík, Iceland – 1000 MWth Nesjavellir hot water main, Iceland – 1600 L/s , 85°C The pearl, Iceland Integrated or cascaded Supply mains Storage tanks arrangement Grafarholt pumping station, Iceland Xianyang, People Republic of China Reykjavík, Iceland Pump stations Distribution systems House connections GEOTHERMAL UTILIZATION Potential direct use applications • Characteristics of the resource: temperature, flow, chemistry and other parameters related to its sustainable utilization. Geothermal District heating in China Geothermal district heating - China Development of district heating systems for space heating (and domestic hot water). Geothermal water extracted and distributed in an efficient and modern way. Verkís´ involvement: Project Feasibility Conceptual Construction management study Design supervision Key figures: Heated indoor area 2008: ~ 880.000 m2 Project’s development period: Heated indoor area 2013: ~ 9.000.000 m2 2004 –ongoing Number of heat centrals 2013: ~ 90 360 [GWh] heat produced/hs Number of production wells: ~ 120 530 [MWth] Total capacity Number of Reinjection wells: ~ 94 Future plans and increasing (Reinjection mainly in Shandong and Hebei) very rapidly!!! DISTRICT HEATING - OVERVIEW Main parts of a geothermal district heating system Reinjection well 1 2 3 4 5 HC End users Production well 1: Production- & Re-injection wells 2: Gathering system, piping from wells to heat central 3: Heat central (HC) with or without peak load 4: Distribution system, supply & return pipes 5: End users / customers, radiators, floor heating Geothermal Heating - Guidelines • Sought outcome when utilizing geothermal energy: optimize energy extraction • Golden rules in geothermal space heating systems: • Utilize thermal energy as much as possible, or economically feasible before disposal or re-injection. • Keep the systems simple • Get as high T as possible in the first step. • Adapt design to geothermal resource- • Re-injection is almost always the future goal for sustainability. Re-injection well in XianYang General considerations • Preferred temperatures: production wells • supply: 70-80°C Geothermal fluid to Make-up and drainage system chemical treatment equipment • Return: 25-35°C District heating, Gas supply connection boiler(s) District heating, Circulation return connection pumps Radiatoor heating • Preferred ΔT (55/45°C) and/or floor heating (temperature difference): (45/35°C) Process heat • 40-45°C exchangers (PHE) Production well(s), To drainage • General criteria: ~100°C system ~40°C – Chemical composition of geothermal fluid – Availability, sustainable flow Typical heat central in Xianyang, with boiler rates etc and heat pump – Local conditions – Market: density, compatibility… – Local regulations, restrictions Distribution system - Design • Thermal losses 10% of max power (up to 30% in old systems): • 5 W/m2 • 45 kWh/m2 (Operating 12 months pr. year) • Peak load demand: up to 50W/m2 • With Improved insulation and floor heating: 40W/m2 • High quality pipes, pre-insulated bonded steel pipe • Reduced heat loss • High temperature difference between supply and return • Lower investment cost in the distribution system, (smaller pipes) • Reduced pumping cost, (lower operational cost) • Better use of extracted geothermal water Heat Central • Receives heat from various resources • Geothermal hot water • Ground source heat (GSHP) • Waste heat from industry • Heat from power plants • Boilers • Base load heat boilers • Heat pumps, base load or additional load • Peak load boilers • Supply temperature control • Pumping HC400 - Xianyang Room temperture control • In old constant flow systems • Supply water temperature control done at the heat central. • Fine tuning of indoor temperature by opening and closing windows or with manual on/off valves. • In modern radiator or floor heating systems – Room temperature controller on the radiator/floor heating supply pipe, controlling the room temperature. POWER AND ENERGY DEMAND • Typical load duration curve • Heating season in, China. 15 Nov. to 15 March the following year Total 120 days heating season 120 days Xianyang - China Provinces – Geothermal utilization 中国 Peoples Republic of China Shaanxi province Xianyang City Wugong • Other locations on planning stage • 3.4 Million m2 of heated area XianYang June 2013 • 40 heat centrals • Reinjection problems, sandstone Hebei Province 1. Xuanhua Project 2. Rongcheng Project 3. Xiong County 4. Baoding Municipality 5. Boye 6. Xinji City • 5 Million m2 of heated area Xiong County February 2014 • 32 heat centrals • Sucessful Re-injection Shandong Province 1. Qingyun 2. Laoling 3. Shanghe County 4. Heze City • 360.000 m2 of heated area • 7 Heat centrals (2013) OLD HEATING SYSTEMS • Poor insulation, high power demand and heating energy • Single pipe, old radiator systems in China • Design temperature drop: 90°C -70°C, Coal boiler plant • Old heating systems are not suitable for geothermal!!! House heating – Parallel system • Parallel system, improved efficiency and easier to manage • Offers better retrofit and combination possibilities, e.g. with floor heating Parallel pipe system I Parallel pipe system II Radiator Radiator Radiator Radiator Radiator Radiator Radiator Radiator Radiator Radiator Radiator Radiator Return pipe Return pipe Supply pipe Supply pipe SPACE HEATING SYSTEMS • Old radiator systems, China • Supply temperature 90°C • Supply temperature 70°C • Not applicable with Geo-DH • Modern radiator systems • Supply temperature 75°C • Return temperature 35°C • Floor heating – new residential bldg´s • In China • Supply temperature 45°C • Return temperature 35°C Max Power demand • Indoor temperature 18°C • Outdoor temperature -12°C • Old apartment buildings – 100 W/m2 (8 kW pr. apartment) • Modern apartment buildings – 40 W/m2 (4 kW pr. apartment) Distribution systems • Modern distribution systems are made of pre-insulated bonded steel pipes, with polyurethane (PUR) insulation and PEH protecting coating • EN253 • Smaller house connections are often pre-insulated PEX pipes Questions? Thank you!.