Analysis of Techniques to Improve Sustainable Performance of Gas-Turbine Based Combined Cycle System

In the present paper the environmental impact of a gas-steam combined cycle, in terms of CO₂ emissions has been supplemented with the energetic analysis of the cycle. The gas turbine based triple-pressure reheat combined cycle incorporates, vapor compression inlet air cooling and air-film turbine blade cooling, to study the improvement in plant performance and sustainability. A parametric study of the effect of compressor pressure ratio (r_p,c), compressor inlet temperature (CIT), turbine inlet temperature (TIT), inlet temperature ratio (r_IT), ambient relative humidity and ambient temperature on performance and sustainability has been carried out. The integration of inlet air cooling and gas turbine blade cooling results in a significant reduction in CO₂ emission per unit plant output. The integration of vapor compression inlet air cooling to gas turbine based combined cycle, has been observed to improve the specific work by more than 10 %. The plant efficiency increases significantly with increase in TIT. For all values of TIT, there exists an optimum r_p,c at which the plant efficiency is maximum. The cost of environmental impact due to CO₂ emission reduces with increase in TIT and decrease in CIT.