DOCSLIB.ORG

Thermodynamic Study of Coupled Steam-Gas Turbine Plant With

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Thermodynamic Study of Coupled Steam-Gas Turbine Plant With E AMEICA SOCIEY O MECAICA EGIEES 35 E 7 S ew Yr, .Y. 00 S The Society shall not be responsible for statements or opinions advanced in papers or discussion at meetings of the Sociey o o is iisios o Secios o ie i is uicaios iscussio is ie oy i e ae is uise G 0 0 0 i a ASME oua Auoiaio o oocoy maeia o iea o esoa use ue cicumsace o aig wii e ai use oisios o e Coyig Ac is gae y ASME o iaies a oe uses egisee wi e Coyig Ceaace Cee (CCC asacioa eoig Seice oie a e ase ee o $3 e age is ai iecy o e CCC 7 Cogess See Saem MA 197 equess o secia emissio o uk eoucio sou e aesse o e ASME ecica uisig eame Coyig © 1995 y ASME A igs esee ie i USA Downloaded from http://asmedigitalcollection.asme.org/GT/proceedings-pdf/GT1995/78811/V004T10A005/2406586/v004t10a005-95-gt-170.pdf by guest on 29 September 2021 EMOYAMIC SUY O COUE SEAMGAS UIE A WI SEAM EACIO A IECIO hn Qn, Shnln , nd Yn Yn eame o owe Egieeig ai Siuiig Egieeig Isiiue ai 151 eoes euic o Cia ABSTRACT Subscripts m mixed working fluids A type of coupled steam—gas turbine plant is pro- a air posed here. It is composed of a regenerative extraction g gas steam turbine and a steam injected gas turbine. Extracted s steam steam of the regenerative extraction steam cycle is not used t turbine to heat water through the regenerative feed—water heater c compressor as in conventional plant, but injected into a gas turbine to b extraction point or burner augment the output of the gas turbine, while the exhaust f fuel gas of the gas turbine now displaces the extracted steam to GT. ST refers to gas turbine and steam turline heat the feed water of the steam turbine plant. The pro- 1,2,3••• positions as shown in figure 1. posed repowering turbine plant has two merits: the further utilization of extraction steam and the elimination of the Superscripts complicated waste heat recovery boiler of a conventional T3 temperature of gas turbine inlet steam injected gas turbine plant, in favor of a gas—to—wat- Tr fuel inlet temperature er heat exchanger. after refitted into coupled plant NOMENCLATURE INTRODUCTION C average specific heat capacity kJ / (kg • K) To increase the energy utilization ratio in a gas turbine f fuel—to—air ratio Brayton cycle , "Cheng cycle heat engine", or "Dual fluids G flowrate kg / s parallel compound cycle gas turbine", or "Steam injected h enthalpy kJ/kg gas turbine" was patented in reference'. In the patents, a p pressure Pa heat recovery boiler, which is used to generate steam, is T temperature K added to the exhaust duct of the gas turbine. The steam w specific work kw / kg generated by the boiler is injected into the combustion x injected steam—to—air ratio — chamber or turbine to augment the power output and a extraction steam fraction — thermal efficiency of the gas turbine plant. Many Steam In- 0 low heating value of fuel kJ / kg jected Gas turbine or STIG plants as called by Gereral rf efficiency — Electric have been applied around the world. Presented at the International Gas Turbine and Aeroengine Congress and Exposition Houston, Texas - June 5-8,1995 To increase the thermal efficiency of a steam turbine minimum temperature difference in the heat recovery boil- Rankine cycle, steam is extracted through the extraction er restricts the steam injection amount, or x m , the ratio of openings of the steam turbine to preheat the feed water of injected steam to intake air of the gas turbine. For the giv- the steam turbine plant. en pinch point temperature difference OTPP and the hot That is to say, for STIG gas turbine plant, a heat re- end temperature difference ATh of the heat recovery covery boiler is necessary to generate steam. While for boiler, there is a critical injected steam—to—air ratio the regenerative extraction steam turbine plant, steam, which connertroral xT. When x m >xcr, the performance of the still has the ability to generate power, must be extracted to conventional steam injected gas turbine plant begins to de- Downloaded from http://asmedigitalcollection.asme.org/GT/proceedings-pdf/GT1995/78811/V004T10A005/2406586/v004t10a005-95-gt-170.pdf by guest on 29 September 2021 preheat the feed water. teriorate. Therefore, a coupled steam—gas turbine plant is pro- If the injection steam for gas turbine does not come posed here. The idea of the proposed coupled plant is just from its heat recovery boiler, there is no restriction on the the combination of the steam injection of STIG gas turbine ratio of injected steam—to—air. This can be seen from the and the steam extraction of the steam turbine. The coupled following analgses. plant is composed of a regenerative extraction steam tur- bine and one or several gas turbines. As shown in figure 1, the steam which is extracted from the steam turbine is in- jected into the gas turbines and the exhaust gas of the gas turbines is used to preheat the feed water of the steam tur- bine plant to make best use of energy. The high grade ener- gy o the extracted steam of the steam turbine cycle is util- ized further in the steam injection gas turbine. For example, the temperature of the extracted steam of steam turbine S in this paper is 330 C (No.5 regenerator). The extracted steam can be injected into a gas turbine to gener- ate more power. And then, the exhaust gas replaces the ex- tracted steam to heat feed water of the steam turbine. The Fig. I diagram of coupled steam—gas turbine plant exhaust temperature of the two gas turbines of the pro- posed two schemes are respectively 346t , 396t . The exhaust gas can replace steam to heat feed water. A Snecific work gas—to—water heat exchanger takes the place of one or sev- The specific work of a steam injected gas turbine is: eral steam—to—water regenerators. The entropy production w=(1 ++ m (3 ——( —a in a gas—to—water heat exchanger is slightly more than a hm enthalpy of mixed working fluid. heat recovery boiler or a steam—to—water regenerator. Here, the injected steam comes from the extraction opening There were some gas—to—water heat exchengers which of regenerative extraction steam turbine of the coupled have been used in other kinds of combined turbine plants. plant. For convenience sake, suppose the steam is injected Because of the utilization of the extracted steam of the into the combustion chamber only. steam turbine and the exhaust gas of the gas turbine of the w =[(1 + fc a3 +C](3 — coupled plant, the output and efficiency of the plant are —C pa 1( T 2 — imoe. here, T ; —isentropic temperature at position i, C C g C S —average specific heat of air, gas and steam. THEORETICAL CONSIDERATIONS OF Therefore, STEAM AND GAS TURBINES WITH STEAM Ow _ o 7/ 4 ) EXTRACTION AND INJECTION O — t C S3 o + s3 3 — The ratio of fuel—to—air after steam injection can be For the coupled plant, the main connection of steam determined by the heat balance in the combustion and gas turbines is the extraction or injection steam. the ef- chamber: fect of steam extraction and injection on the performance — 2 O b =C J T — of steam and gas turbines, the appropriate amount of ex- (3 +( hp) + m C31 traction and injection steam should take preconsiderations. ( 3 — T 4 ) here, T b —steam temperature at extraction point. Hence, 1. Gas Turbine Performance with Steam Injection 3 —+ — 4 Ca3( C ,, , (3 ) For the conventional steam injected gas turbine, the f= n48+h11—h13 injected steam is generated by the heat recovery boiler. The 2 hence, fST> fGT in any case. T 3 — — b ) Therefore, the specific work and efficiency of the = C a3 ( 2 ) + C S3 T 3 steam injected gas turbine of the coupled plant will increase n b B+hff —hf ^nb0+hf —hf' as the increase of steam—to—air ratio. = + m f0 , f,--fuel—to—air ratio used for the heating of air and 2. Steam Turbine Performance after Steam Extraction seam eseciey. As shown in figure 2, suppose the original steam tur- bine has three extaction points a, b, and c, corresponding Downloaded from http://asmedigitalcollection.asme.org/GT/proceedings-pdf/GT1995/78811/V004T10A005/2406586/v004t10a005-95-gt-170.pdf by guest on 29 September 2021 o = , we have, x extraction steam fractions are aa, a b , and a,. The ex- aw traction point for steam injection of the gas turbine is de- am =17(C a3 +CS3a(3 — termined by the requirement of steam injection of the gas The inequality indicates that the specific work of 'a turbine. The parameters of the selected extraction point are seam iece gas uie iceases as e aio o Tb , Pb' extraction steam fraction steam—to—air increases. is a'b, a'b x.G,, / G. Assume the other factors are ucage. See ig.2. Efficiency The injection steam has an effect on the efficiency of T •6 the gas turbine plant. For the conventional steam injected gas turbine, when x m <x,, the efficiency n increases as N a the x m increases, when x m >x cr, the efficiency will de- crease as xm increases. However, when the injected steam is not generated by a heat recovery boiler, the relationships are not the same.
Load more

Recommended publications
  • Evaporative Gas Turbine Cycles. a Thermodynamic Evaluation of Their
    Department of Heat and Power Engineering Evaporative gas turbine cycles- A thermodynamic evaluation of their potential by Per Rosin MASTER ismm#N if ms bocmmt is wmnts FWBH SALES PltlUfTEI Dokumentutgivere HJ/LTH Dokumentnamn Ookumentbeteckning Inst f6r Varme- och kraftteknik Rapport ISRN LUTMDN/TMVK-7010-SE Hendliggare Utgivnlngsdatum Arendebetecknlng Mars 1993 FOriettere Rosdn, Per M. Dokumenxtitel och undertitol Evaporative gas turbine cycles- A thermodynamic evaluation of their potetial Relerat (semmandrag) The report presents a systematic method of thermodynamically evaluating different gas turbine cycles, treating the working fluids as ideal gases (cp = cp (T)). All models used to simulate different components in the cycles are presented in the report in detail and then connected in a computer program fully developed by the author. The report focuses on the theme of evaporative gas turbine cycles, in which low level heat is used to evaporate water into the compressed air stream between the compressor and recuperator. This leads to efficiency levels close to a comparable combined cycle but without the steam bottoming cycle! A parametric analysis has been conducted with the aim of deciding the best configuration of an evaporative cycle both for an uncooled expander and for a cooled expander. The model proposed to simulate the cooled expander is a combination between two existing models. Relerat ekrivet av Rosdn Per M. Foreleg till ytterligare nyekelord evaporation, humidification, gas turbine, intercooler, aftercooler, recuperator, economiser, air-cooled expander, humid air turbine cycle, HAT, steam injection Klattitiketionnystem och -klau(er) Indextermer (enge kella) 12 10 Omflng Ovriga bibliogretiske uppgiftei 6 2 67 sidor SIS Sprlk engelska en lig t Sekretessuppgifter ISSN ISBN ; .• e ..
    [Show full text]
  • Advanced Power Cycles with Mixtures As the Working Fluid
    Advanced Power Cycles with Mixtures as the Working Fluid Maria Jonsson Doctoral Thesis Department of Chemical Engineering and Technology, Energy Processes Royal Institute of Technology Stockholm, Sweden, 2003 Advanced Power Cycles with Mixtures as the Working Fluid Maria Jonsson Doctoral Thesis Department of Chemical Engineering and Technology, Energy Processes Royal Institute of Technology Stockholm, Sweden, 2003 TRITA-KET R173 ISSN 1104-3466 ISRN KTH/KET/R--173--SE ISBN 91-7283-443-9 Contact information: Royal Institute of Technology Department of Chemical Engineering and Technology, Division of Energy Processes SE-100 44 Stockholm Sweden Copyright © Maria Jonsson, 2003 All rights reserved Printed in Sweden Universitetsservice US AB Stockholm, 2003 Advanced Power Cycles with Mixtures as the Working Fluid Maria Jonsson Department of Chemical Engineering and Technology, Energy Processes Royal Institute of Technology, Stockholm, Sweden Abstract The world demand for electrical power increases continuously, requiring efficient and low-cost methods for power generation. This thesis investigates two advanced power cycles with mixtures as the working fluid: the Kalina cycle, alternatively called the ammonia-water cycle, and the evaporative gas turbine cycle. These cycles have the potential of improved performance regarding electrical efficiency, specific power output, specific investment cost and cost of electricity compared with the conventional technology, since the mixture working fluids enable efficient energy recovery. This thesis shows that the ammonia-water cycle has a better thermodynamic performance than the steam Rankine cycle as a bottoming process for natural gas- fired gas and gas-diesel engines, since the majority of the ammonia-water cycle configurations investigated generated more power than steam cycles.
    [Show full text]
  • Gas Turbine Cycle Incorporating Simultaneous, Parallel, Dual-Mode Heat Recovery
    Europaisches Patentamt J European Patent Office 00 Publication number: 0 275 121 Office europeen des brevets A2 EUROPEAN PATENT APPLICATION Application number: 88100532.6 IntCI.*: F 01 K 21/04 F 02 C 3/30 Date of filing: 15.01.88 Priority: 15.01.87 US 3548 ® Applicant: El-Masrl, Maher A. 9 Clubhouse Lane Date of publication of application: Wayland, MA 01778 (US) 20.07.88 Bulletin 88/29 @ Inventor: El-Masrl, Maher A. Designated Contracting States: 9 Clubhouse Lane CH DE FR QB IT LI Wayland, MA 01778 (US) @ Representative: Heidrlch, Udo, Dr. jur., Dipl.-Phys. Franziskanerstrasse 30 D-8000 Miinchen 80 (DE) @ Gas turbine cycle incorporating simultaneous, parallel, dual-mode heat recovery. (g?) The cycle includes water-injection, steam-injection, re- cuperation (or regeneration) and waste-heat boiler heat recovery in an arrangement that provides high thermal efficiency, flexible operation in a cogeneration plant and favorable capital cost in relation to thermodynamic performance when compared to currently practiced cycles. In the present cycle, the sensible enthalpy of the exhaust gases between turbine exit and stack is used to simultaneously and in-parallel heat both air and water/steam. A smaller amount of water is boiled than in the known Cheng cycle, in which the exhaust heat is used only to heat water/steam. Thus, the latent heat exhausted at the stack in the present cycle is lower than that for the Cheng cycle resulting in higher efficiency. CM S CM Si Bundesdruckerei Berlin 1 0 275 121 Description GAS TURBINE CYCLE INCORPORATING SIMULTANEOUS, PARALLEL, DUAL-MODE HEAT RECOVERY bine combustor pressure.
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 6,644,011 B2 Cheng (45) Date of Patent: Nov
    USOO6644O11B2 (12) United States Patent (10) Patent No.: US 6,644,011 B2 Cheng (45) Date of Patent: Nov. 11, 2003 (54) ADVANCED CHENG COMBINED CYCLE 5,370,772 A * 12/1994 Arpalahti et al. ........ 60/39.182 5,613,356 A * 3/1997 Frutschi................... 60/39.182 (75) Inventor: Dah Yu Cheng, Los Altos Hills, CA 6.256,978 B1 7/2001 Gericke et al. .......... 60/39.182 (US) * cited by examiner (73) ASSignee: She's yet Systems, Inc., Mountain Primary Examiner Michael Koczo 1eW, (US) (74) Attorney, Agent, or Firm-Cooper & Dunham LLP (*) Notice: Subject to any disclaimer, the term of this (57) ABSTRACT patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days. An Advanced Cheng Combined Cycle engine is a combi nation of the Cheng Cycle or the Advanced Cheng Cycle and (21) Appl. No.: 09/816,588 a combined cycle, and Serves to further enhance the power 9 generation capability of either the Cheng Cycle, the (22) Filed: Mar 23, 2001 Advanced Cheng Cycle, or the combined cycle alone. Agas O O turbine is provided, having a turbine generating power, a (65) Prior Publication Data compressor receiving power from the turbine, and a com US 2001/0039797 A1 Nov. 15, 2001 bustion chamber to which is input compressed air from the compressor along with fuel and combustion products for Related U.S. Application Data producing energy to drive the turbine, the gas turbine (60) Provisional application No. 60/191,599, filed on Mar. 24, producing a hot stream gas. Aheat recovery Steam generator 2000.
    [Show full text]
  • Thermodynamic Modelling and Optimization of a Dual Pressure Reheat Combined Power Cycle
    Sadhan¯ a¯ Vol. 35, Part 5, October 2010, pp. 597–608. © Indian Academy of Sciences Thermodynamic modelling and optimization of a dual pressure reheat combined power cycle T SRINIVAS School of Mechanical and Building Sciences, Vellore Institute of Technology University, Vellore 632 014 e-mail: [email protected] MS received 11 September 2008; revised 18 February 2010; accepted 19 July 2010 Abstract. Heat recovery steam generator (HRSG) plays a key role on performance of combined cycle (CC). In this work, attention was focused on a dual pressure reheat (DPRH) HRSG to maximize the heat recovery and hence performance of CC. Deaerator, an essential open feed water heater in steam bottoming cycle was located to enhance the efficiency and remove the dissolved gasses in feedwater. Each of the heating section in HRSG is solved from the local flue gas condition with an aim of getting minimum possible temperature difference. For high performance, better conditions for compressor, HRSG sections, steam reheater and deaerator are developed. The CC system is optimized at a gas turbine inlet temperature of 1400◦C due to the present available technology of modern gas turbine blade cooling systems. The exergetic losses in CC system are compared with each other. The present DPRH HRSG model has been compared and validated with the plant and published data. Keywords. Combined cycle; dual pressure; deaerator; exergy analysis; heat recovery steam generator. 1. Introduction Combined cycle (CC) power plants are gaining wider acceptance due to more and more avail- ability of natural gas, now a days, because of their higher overall thermal efficiencies, peaking and two-shifting capabilities, fast start-up capabilities and lesser cooling water requirements.
    [Show full text]
  • Offshore Rankine Cycles
    Offshore Rankine Cycles Jo Brandsar Master of Energy and Environmental Engineering Submission date: June 2012 Supervisor: Trygve Magne Eikevik, EPT Co-supervisor: Armin Hafner, SINTEF Energy Research Norwegian University of Science and Technology Department of Energy and Process Engineering Abstract This paper summarizes my master thesis during the spring semester 2012 at the Institute of Energy and Process Engineering, NTNU, Norway. The project was given to me as a collaboration with an ongoing project at SINTEF Energy Re- search. The focus represent electricity production offshore by applying a Rankine cycle with surplus heat as the energy source. Investigations concern foremost a comparison between steam and organic cycles and the effect the waste heat recov- ery unit (WHRU) has on the cycle as a whole. I would like to thank; my supervisors, Prof. Trygve M. Eikevik, Department of Energy and Process Engineering, NTNU, Armin Hafner and Daniel Rohde, SIN- TEF Energy, for technical guidance; my fellow inmates at room B432 for moral support and Atle Brandsar for final proofreading. I Sammendrag Tittelen p˚adenne oppgaven - "Offshore Rankine Cycles" - er svært generell og dekker et stort spekter av tekniske felt, f.eks. termodynamiske sykluser (Rankine, ORC, Bray- ton, Kalina, etc.), mekanisk utstyr (gass-/dampturbin, varmevekslere og ekstra utstyr) og sikkerhetsaspekter (brennbar og/eller giftig væske, høye temperaturer og trykk) for ˚anevne de viktigste. Avhandlingen forsøker ˚agi en kortfattet oversikt over alle kri- tiske punkter og alternativer, og over implementering av en varmegjenvinningsprosess p˚a offshore-anlegg, selv om fokus har vært p˚ato mer spesifiserte tilfeller, nemlig: Sammenligning av en dampsyklus vs.
    [Show full text]
  • Assessment and Modelling of the Waste Heat Availability from Gas Turbine Based CHP Systems for ORC Systems
    European Association for the International Conference on Renewable Energies and Power Quality Development of Renewable Energies, Environment (ICREPQ’12) and Power Quality (EA4EPQ) Santiago de Compostela (Spain), 28th to 30th March, 2012 Assessment and modelling of the waste heat availability from gas turbine based CHP systems for ORC systems E. Firdaus1, K.Saaed1, D.Bryant2, M.Jones1, S.Biggs3 and B.Bahawodin1 1 Computing Engineering and Mathematics University of Brighton BN2 4GJ (United Kingdom) Phone/Fax number: +0044 203 0060166/65, e-mail: [email protected], [email protected], [email protected], [email protected] 2 Heatcatcher Ltd. The Roller Mill Mill Lane Uckfield TN22 5AA (United Kingdom) Phone/Fax number: +0044 203 0060166/65, e-mail: [email protected] 3 Efficient Air Ltd. The Roller Mill Mill Lane Uckfield TN22 5AA (United Kingdom) Phone/Fax number: +0044 182 5748150/51, e-mail: [email protected] Abstract. This paper presents the findings of modelling of Interest in capturing low-grade (low temperature) heat waste heat availability from a Combined Heat and Power (CHP) has grown dramatically in past decades [1]. Important system with a rated electrical output of 4.35 MW and steam alternatives have been proposed to generate electricity production of 8,165 kg/hr at 16 barg. The model has been from low temperature heat sources such as solar thermal developed using HYSYS DynamicsTM. The amount of waste heat power, industrial waste heat, engine exhaust gases and available from the CHP system is dependent on the ambient air, domestic boilers [1]-[2].
    [Show full text]
  • Topcycle: a Novel High Performance and Fuel Flexible Gas Turbine Cycle
    sustainability Concept Paper TopCycle: A Novel High Performance and Fuel Flexible Gas Turbine Cycle Simeon Dybe 1,*, Michael Bartlett 2, Jens Pålsson 2 and Panagiotis Stathopoulos 3 1 Fluid Dynamics, Technische Universität Berlin, 10623 Berlin, Germany 2 Phoenix BioPower AB, Drottning Kristinas väg 18, 114 24 Stockholm, Sweden; [email protected] (M.B.); [email protected] (J.P.) 3 Unsteady Thermodynamics in Gas Turbine Processes, Technische Universität Berlin, 10623 Berlin, Germany; [email protected] * Correspondence: [email protected] Abstract: High pressure humidified cycles can combine high operational flexibility and high thermal efficiency. The current work introduces such a cycle, namely TopCycle, which provides the necessary combustion infrastructure to operate on a wide fuel variety in a steam-rich atmosphere. The cycle configuration is presented in detail, and its operation is exemplified on the basis of simulation results. Operation at design condition results in electric efficiencies higher than 50% (lower heating value (LHV)) and power densities higher than 2100 kW/kgair (referred to intake air flow). A sensitivity analysis identifies the cycle performance as a function of representative parameters, which provide the basis for future operation and design improvements. As for any gas turbine cycle, TopCycle’s electric efficiency can be effectively improved by increasing the turbine inlet temperature, optimizing the economizer heat recovery, as well as elevating the working pressure. Finally, TopCycle’s performance is compared to a state-of-the-art combined cycle (CC) at equivalent operation parameters. The TopCycle operates at an elevated electric efficiency and considerably higher power density, which can be transferred into smaller plant footprint and dimensions and thus lower investment costs at equal power output in comparison to a CC.
    [Show full text]
  • Dynamic Modelling of a Cheng Cycle
    Dynamic modelling of a Cheng Cycle Citation for published version (APA): Doelman, R. B. (1995). Dynamic modelling of a Cheng Cycle. Technische Universiteit Eindhoven. Document status and date: Published: 01/01/1995 Document Version: Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license above, please follow below link for the End User Agreement: www.tue.nl/taverne Take down policy If you believe that this document breaches copyright please contact us at: [email protected] providing details and we will investigate your claim.
    [Show full text]
  • Power Enhancement of the Brayton Cycle by Steam Utilization
    archives of thermodynamics Vol. 33(2012), No. 3, 39–50 DOI: 10.2478/v10173-012-0016-x Power enhancement of the Brayton cycle by steam utilization KRZYSZTOF JESIONEK1 ANDRZEJ CHRZCZONOWSKI1 PAWEŁ ZIÓŁKOWSKI 2 ∗ JANUSZ BADUR2 1 Wrocław University of Technology, Faculty of Mechanical and Power Engineering, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland 2 The Szewalski Institute of Fluid-Flow Machinery of Polish Academy of Sciences, Fiszera 14, 80-231 Gdansk, Poland Abstract The paper presents thermodynamic analysis of the gas-steam unit of the 65 MWe combined heat and power station. Numerical analyses of the station was performed for the nominal operation conditions determining the Brayton and combined cycle. Furthermore, steam utilization for the gas turbine propulsion in the Cheng cycle was analysed. In the considered modernization, steam generated in the heat recovery steam generator unit is directed into the gas turbine combustion chamber, resulting in the Brayton cycle power increase. Computational flow mechanics codes were used in the analysis of the thermodynamic and operational parameters of the unit. Keywords: Brayton cycle; Gas-steam unit; Cheng cycle; Numerical analysis; CHP Nomenclature h –specificenthalpy,kJ/kg k – relative steam flux coefficient lt –specificwork,kJ/kg N –power,kW ∗Corresponding author. E-mail address: [email protected] Authenticated | 195.187.97.1 Download Date | 12/12/12 9:52 AM 40 K. Jesionek, A. Chrzczonowski, P. Ziółkowski and J. Badur m˙ – mass flux, kg/s P – pressure, Pa ˙ QC – heat flux, kWt ˙ Qchem – chemical energy flux, kW t – temperature, oC T – temperature, K Wd – fuel calorific value, kJ/kg Greek symbols η –efficiency,% Π – compression Subscripts a –air el – electrical EC –CHPstation ex –exhaust f –fuel GT – at the gas turbine outlet i –internal m – mechanical s –steam TIT – turbine inlet temperature (average temperature in combustion chamber) 1s, 2s,..
    [Show full text]
  • Thermodynamic Modeling and Optimization of Multi-Pressure Heat Recovery Steam Generator in Combined Power Cycle
    Journal of Scientific & Industrial Research SRINIVAS et al: OPTIMUM PRESSURE HEAT RECOVERY STEAM GENERATOR IN COMBINED CYCLE Vol. 67, October 2008, pp.827-834 827 Thermodynamic modeling and optimization of multi-pressure heat recovery steam generator in combined power cycle T Srinivas1*, A V S S K S Gupta2 and B V Reddy3 1School of Mechanical and Building Sciences, VIT University, Vellore 632 014 2Department of Mechanical Engineering, J N T U College of Engineering, Kukatpally, Hyderabad 500 080 3Faculty of Engineering and Applied Sciences, University of Ontario Institute of Technology, Oshawa, ON, L1H 7K4, Canada Received 27 September 2007; revised 17 July 2008; accepted 21 July 2008 Optimum configuration for single pressure (SP), dual pressure (DP) and triple pressure (TP) heat recovery steam generator (HRSG) is presented to improve heat recovery and thereby exergy efficiency of combined cycle. Deaerator was added to enhance efficiency and remove dissolved gases in feed water. A new method was introduced to evaluate low pressure (LP) and intermediate pressure (IP) in HRSG from local flue gas temperature to get minimum possible temperature difference in heaters instead of a usual fixation of pressures. Optimum location for deaerator was found at 1, 3 and 5 bar respectively for SP, DP and TP in heat recovery at a high pressure (HP) of 200 bar. Results also showed optimum pressure for air compression and steam reheater by means of three categories of heat recovery. Key words: Combined cycle, Deaerator, Exergy analysis, Heat recovery, Multi pressure, Steam generator Introduction Ragland & Stenzel6 compared four plant designs using Combined cycle (CC) power plants are gaining wider natural gas with a view of cost benefits achieved through acceptance due to more and more availability of natural HRSG optimization.
    [Show full text]
  • Thermodynamic Properties of Humid Air and Their Application in Advanced Power Generation Cycles
    Thermodynamic properties of humid air and their application in advanced power generation cycles Xiaoyan Ji Doctoral Thesis in Chemical Engineering KTH-Royal Institute of Technology Department of Chemical Engineering and Technology Energy Processes SE-100 44 Stockholm, Sweden Contact information: Royal Institute of Technology School of Chemical Science and Engineering, Division of Energy Processes SE-100 44 Stockholm Sweden Copyright ©Xiaoyan Ji, 2006 All rights reserved Printed in Sweden Universitetsservice US AB Stockholm, 2006 TRITA-KET R229 ISSN 1104-3466 ISRN KTH/KET/R--229--SE ISBN 91-7178-437-3 2 Thermodynamic properties of humid air and their application in advanced power generation cycles Xiaoyan Ji School of Chemical Science and Engineering, Energy Processes KTH-Royal Institute of Technology, Stockholm, Sweden Abstract Water or steam is added into the working fluid (often air) in gas turbines to improve the performance of gas turbine cycles. A typical application is the humidified gas turbine that has the potential to give high efficiencies, high specific power output, low emissions and low specific investment. A heat recovery system is integrated in the cycle with a humidifier for moisturizing the high-pressure air from the compressor as a kernel. Based on today’s gas turbines, the operating temperature and pressure in the humidifier are up to about 523 K and 40 bar, respectively. The operating temperature of the heat exchanger after the humidifier is up to 1773 K. The technology of water or steam addition is also used in the process of compressed air energy storage (CAES), and the operating pressure is up to 150 bar.
    [Show full text]