Performance improvement of biomass-fueled closed cycle gas turbine via compressor inlet cooling using absorption refrigeration; thermoeconomic analysis and multi-objective optimization

Abstract

Compressor inlet air cooling is a practical and applied methodology to enhance the conventional open cycle gas turbine power plants. This methodology in this paper, is proposed to be applied on an innovative biomass-fueled Closed Cycle Gas Turbine (CCGT), in which the exhaust gas waste heat is utilized to run an ammonia-water absorption refrigeration cycle for compressor inlet cooling. Thermoeconomic analysis is presented to investigate the two systems (with and without inlet cooling) and multi-objective optimization is conducted to compare their performances at optimal operating conditions. Levelized Cost of Electricity (LCOE) and exergy efficiency are selected as the two rational objectives. The results indicated that, for all the practical range of operating conditions, compressor inlet cooling significantly improves the system performance in terms of both thermodynamics and economics, despite the additional costs imposed on the overall system by adding the absorption refrigeration cycle. It is found that, under the optimal operating conditions, incorporation of compressor inlet cooling results in an improvement of net power and exergy efficiency by 30.1%, meanwhile the LCOE would be reduced by 22.5% when inlet cooling is employed.