American Journal of Energy Research
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American Journal of Energy Research. 2014, 2(2), 35-41
DOI: 10.12691/ajer-2-2-3
Open AccessArticle

A Thermal Analysis and Optimization of a Combined Cycle by Several Technologies

KILANI Nihed1, , KHIR Tahar1 and BEN BRAHIM Ammar1

1National School of Engineers of Gabes, University of Gabes Omar Ibn El Khattab St, 6029 Gabes, Tunisia,

Pub. Date: April 21, 2014

Cite this paper:
KILANI Nihed, KHIR Tahar and BEN BRAHIM Ammar. A Thermal Analysis and Optimization of a Combined Cycle by Several Technologies. American Journal of Energy Research. 2014; 2(2):35-41. doi: 10.12691/ajer-2-2-3


Thermodynamic optimization of four power plant installations with different technology is presented and discussed in this paper. Numerical optimization of the different cycles is performed in aim to obtain higher efficiency. Thermal analysis performance for the fourth cycles is performed for a define range of operating parameters using a calculation code established according to EES software. The first studied cycle is a simple combined cycle containing gas turbine cycle with a steam injection system, one pressure heat recovery steam generator HRSG and a steam turbine cycle. The overall efficiency of this cycle in inlet ambient conditions is about 46%. The second cycle is a combined one with steam injection system for which the steam injected is generated outside the HRSG using heat recovery system at the air compressor outlet. The performance of this cycle in the same initial conditions is higher of about 1%. The third plant is a combined cycle with steam injection and two steam extractions from steam turbine and two open feedwater heaters. The performance of this cycle is higher of about 1% compared to the first one. The last considered power plant technology is a combined cycle with heat recovery at air compressor outlet and steam extraction. Obtained results show that the optimum operating parameters leading to the best performances are not the same for different cycles.

combined cycle steam extraction heat recovery optimization thermal efficiency

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