Energy, exergy and sensitivity analyses of a hybrid combined cooling, heating and power (CCHP) plant with molten carbonate fuel cell (MCFC) and Stirling engine

Abstract

A hybrid combined cooling, heating and power (CCHP) system which consists of molten carbonate fuel cell (MCFC), Stirling engine and double effect LiBr/H2O absorption chiller is introduced and analyzed. Molten carbonate fuel cell is the main power production source which its exhausted heat is used as heat source of the Stirling engine. Exhausted heat from the Stirling engine is used as heat source of the absorption chiller’s generator. The produced power of the process is 6482 kW, also it provides 2137 kW heat duty and 1372 kW cold duty. Performance of the process is evaluated by energy and exergy analysis methods. Also sensitivity of the overall and electrical efficiencies to the fuel utilization factor, air flow rate to the burner, burner outlet temperature and oxidant flow rate are analyzed. Results of the energy analysis show that overall and electrical efficiencies are 71.71% and 42.28% respectively. Exergy analysis shows that molten carbonate fuel cell, Stirling engine and gas turbine have considerable efficiencies. Highest exergy destruction rate is related to the CH4 and H2 burners that mostly is because of the irreversible nature of the combustion.