Energy and exergy analysis of steam cooled reheat gas-steam combined cycle
Abstract
This paper deals with parametric energy and exergy analysis of reheat gas-steam combined cycle using closed-loop-steam-cooling. Of the blade cooling techniques, closed-loop-steam-cooling has been found to be superior to air-film cooling. The reheat gas-steam combined cycle plant with closed-loop-steam-cooling exhibits enhanced thermal efficiency (around 62%) and plant specific work as compared to basic steam-gas combined cycle with air-film cooling as well as closed-loop-steam cooling. Further, with closed-loop-steam-cooling, the plant efficiency, reaches an optimum value in higher range of compressor pressure ratio as compared to that in film air-cooling. It has also been concluded that reheat pressure is an important design parameter and its optimum value gives maximum plant efficiency.
Component-wise inefficiencies of steam cooled-reheat gas-steam combined cycle based on the second-law-model (exergy analysis) have been found to be the maximum in combustion-chamber (≈30%), followed by that in gas turbine (≈4%).- Publication:
-
Applied Thermal Engineering
- Pub Date:
- 2007
- DOI:
- 10.1016/j.applthermaleng.2007.03.011
- Bibcode:
- 2007AppTE..27.2779S
- Keywords:
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- Reheat gas turbine;
- Closed-loop-steam-cooling;
- Energy and exergy analysis