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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 (rp,c), compressor inlet temperature (CIT), turbine inlet temperature (TIT), inlet temperature ratio (rIT), 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 %.

A systematic and comprehensive first law analysis of a cooled gas turbine cycle subjected to vapor compressor inlet air cooling (VC-IAC) has been conducted in our study. Film air cooling technique has been implemented to cool the gas turbine (GT) buckets. The gas turbine is subjected to variation of various operating and ambient parameters and the corresponding effect is analyzed to find out the optimal one. The integration of VC-IAC has been reported to further enhance the plant specific work and plant efficiency of gas turbine cycle, the enhancement being higher in regions having a hot and dry climate. This increase in cycle performance due to VC-IAC has been found superior in case of bucket cooled GT cycle when compared to uncooled one. It has further been witnessed that the plant specific work increases by more than 0.35 % and the plant efficiency increases by little above 0.1 % for every 1o C drop in CIT.

The integration of inlet air cooling to gas turbine based power utilities is a well accepted practice as this modification to the utility delivers superior utility performance. However, application of inlet-air cooling to drive turbines and specifically to marine mobility sector is rare in literature. Marine vessels are generally propelled by diesel engines, however large marine vessels specifically cruise ships and high speed naval vessels may have requirements of higher speeds and on-board power requirements which can fulfilled by gas turbine driving the propellers while on-board power needs can be met by steam turbine power generated from gas turbine exhaust heat. Such gas-steam combined cycles have the potential to become popular for high capacity marine vessels. The choice of gas turbine based combined cycle power plant for marine vessels in comparison to diesel engine powered vessel is also superior due to lower emission from the former.