Energy efficiency and exergetic analysis of combined cycle plant with inlet air cooling

Abstract

Combined cycle power plants (CCPP) are gaining increased acceptance due to their lower environmental impact over coal-fired power plants, better natural gas availability and renewable balancing capabilities. The objective of this study is to perform energy and exergy analysis of a CCPP with LNG re-gasification cold energy utilisation for inlet air cooling. Energy and exergy analysis comparison is presented including component-level breakdown of exergy destruction. The sensitivity of energy and exergetic performance indices to ambient temperature, compressor inlet temperature, inlet heat exchanger cold duty and steam turbine isentropic efficiency is discussed in detail. The results reveal that for ambient temperature range of 35–45°C, the relative increase in CCPP output power amounts to 14.01%–18.49% (for RH of 40%) and 10.62%–8.50% (for RH of 80%). In a range of RH 40%–80% and ambient temperature 35–45°C, exergy efficiency improvement is 0.20%–1.60%.