Performance Improvement of a Regenerative Gas Turbine Cycle Through Integrated Inlet Air Evaporative Cooling and Steam Injection

Like many developed countries, energy efficiency and environment impact are the most important process in the development of power generation policy in India. A high ambient temperature reduces the air density and makes inlet air cooling (IAC) and steam injection gas turbine (STIG) attractive power augmentation method for existing regenerative gas turbine. With a high back work ratio and a high exhaust temperature, the regenerative cycle gas turbine generation system usually has low generation efficiency particularly in hot ambient weather conditions. From available retrofitting technologies to improve the power generation capacity and efficiency of regenerative cycle gas turbine, IAC through fog cooling and STIG are considered most effective ways to modify an existing simple cycle unit without major description to its original integrity. To evaluate and stimulate the performance of power generation system, a computer program has been developed. The results from computer simulation indicated that the retrofitting of regenerative cycle with IAC and STIG can boost the power output from 30MW to 49.05MW while the generation efficiency can be increased from about 36.99% to 45.21%. The effect of retrofitting techniques on exergy destruction in various system components has also been determined. The exergy destruction rate per MW of power output for different system components (combustion chamber and compressor) reduces while for gas turbine increases for retrofitted cycles. KeywordsRegenerative gas turbine; Retrofitting, Inlet air cooling, STIG, Exergy destruction