A Parametric Study on Exergy and Exergoeconomic Analysis of a Diesel Engine based Combined Heat and Power System

This paper presents exergy and exergoeconomic analysis and parametric study of a Diesel engine based Combined Heat and Power (CHP) system that produces 277 kW of electricity and 282 kW of heat. For this purpose, the CHP system is first thermodynamically analyzed through energy and exergy. Then cost balances and auxiliary equations are applied to subsystems. The exergoeconomic analysis is based on specific exergy costing (SPECO) method. Finally a parametric study is used to show effect of ambient temperature on important energy, exergy and exergoeconomic parameters of the CHP system. Also effects of change in compressor pressure ratio and turbine inlet temperature on these parameters are investigated in different environment temperatures. The results show that increasing ambient temperature increases the work output, heating power and exergoeconomic factor and decreases the exergetic efficiency and cost of exergy destruction. Increasing compressor pressure ratio leads to increase in the work output, heating power, exergetic efficiency, and exergy destruction cost and exergoeconomic factor of the CHP system in all environment temperatures. Also increasing turbine inlet temperature decreases the work output, exergetic efficiency and exergoeconomic factor while increases the heating power as well as exergy destruction cost in all environment temperatures.