Posted: May 4th, 2014

Technical and economic analysis of a combined cycle power

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MCE341 – Thermodynamics II
Spring 2014
Individual Project
Technical and economic analysis of a combined cycle power
generation technology
You have been appointed by an investor in order to provide recommendations concerning
the best investment option for erecting and operating a combined cycle power plant. Based
on the investor’s preliminary analysis the most promising configuration is a combined gassteam
power plant that has a net power output of 450MW. The pressure ratio of the gasturbine
cycle is 14. Air enters the compressor at 300K and the turbine at 1400K. The
combustion gases leaving the gas turbine are used to heat the steam at 8MPa to 400°C in a
heat exchanger. The combustion gases leave the heat exchanger at 460K. An open
feedwater heater incorporated with the steam cycle operates at a pressure of 0.6MPa. The
condenser pressure is 20kPa. Assuming all the compression and expansion processes to be
isentropic. Use EES (or other) software to:

(a) Plot the T-s digram for this cycle
(b) Determine the mass flow rate ratio of air to steam
(c) Determine the required rate of heat input in the combustion chamber
(d) Determine the thermal efficiency of the combined cycle
(e) Study the effects of the gas cycle pressure ratio as it is varied from 10 to 20 on
I. the ratio of gas flow rate to steam flow rate
II. the cycle thermal efficiency
Plot your results as functions of gas cycle pressure ratio and discuss the results.
(f) Comment on the related economics from combined cycle power plants (see
recommended start-up literature resources in the attachment).
By the end of your investigation you are required to submit a report (maximum 10 pages
excluding any appendices), which need to include at least the following:
• Executive summary
• Table of contents
• Introduction (scope of work and content of the report)
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• Description of the combined cycle
• Mathematical formulation (e.g., EES software code)
• Discussion of the results (including a discussion on the effect of pressure ratio on the
ratio of gas flowrate to steam flowrate and on the cycle thermal efficiency as well as a
general discussion concerning the combined cycle economics)
• Conclusions
• References
• Appendices (include any detail work you may wish to report).
Submission due date for the project report is 30 Apr 2014.
The best 4 project reports will be presented in class.
The assignment cover sheet (as posted on iLearn) must be attached to your submission.
Dr. Andreas Poullikkas

Visiting Associate Professor
Mechanical Engineering Department
College of Engineering
22 Mar 2014
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MCE341 – Thermodynamics II
Spring 2014
Recommended Start-Up Literature Resources
1. Xiaotao Zhang, Hideaki Sugishita, Weidou Ni, Zheng Li, Economics and Performance
Forecast of Gas Turbine Combined Cycle, Tsinghua Science & Technology, Volume 10,
Issue 5, October 2005, Pages 633-636, ISSN 1007-0214, http://dx.doi.org/10.1016/S1007-
0214(05)70131-0. (http://www.sciencedirect.com/science/article/pii/S1007021405701310)
2. Ulrika Claeson Colpier, Deborah Cornland, The economics of the combined cycle gas
turbine—an experience curve analysis, Energy Policy, Volume 30, Issue 4, March 2002,
Pages 309-316, ISSN 0301-4215, http://dx.doi.org/10.1016/S0301-4215(01)00097-0.
(http://www.sciencedirect.com/science/article/pii/S0301421501000970)
3. Andreas Poullikkas, Parametric study for the penetration of combined cycle technologies
into Cyprus power system, Applied Thermal Engineering, Volume 24, Issues 11–12,
August 2004, Pages 1697-1707, ISSN 1359-4311,
http://dx.doi.org/10.1016/j.applthermaleng.2003.10.033.
(http://www.sciencedirect.com/science/article/pii/S135943110300379X)
4. James Spelling, Daniel Favrat, Andrew Martin, Germain Augsburger, Thermoeconomic
optimization of a combined-cycle solar tower power plant, Energy, Volume 41, Issue 1,
May 2012, Pages 113-120, ISSN 0360-5442,
http://dx.doi.org/10.1016/j.energy.2011.03.073.
(http://www.sciencedirect.com/science/article/pii/S0360544211002416)
5. Cheng Yang,
Zeliang Yang, Ruixian Cai, Analytical method for evaluation of gas turbine
inlet air cooling in combined cycle power plant, Applied Energy, Volume 86, Issue 6, June
2009, Pages 848-856, ISSN 0306-2619, http://dx.doi.org/10.1016/j.apenergy.2008.08.019.
(http://www.sciencedirect.com/science/article/pii/S0306261908002122)