Investigation of a combined molten carbonate fuel cell, gas turbine and Stirling engine combined cooling heating and power (CCHP) process by exergy cost sensitivity analysis

An integrated combined cooling, heating and power process is investigated and analyzed by advanced exergy cost analysis method. In this process molten carbonate fuel cell, gas turbine and Stirling engine are used for providing the required power (6482 kW). A double effect H2O-Li/Br absorption refrigeration cycle supplies 980 kW cooling. Fuel cell exhaust heat is used to drive Stirling engine and absorption chiller. Also, gas turbine exhaust heat is used to produce steam for heating (2136.6 kW). The main result extracted from the endogenous and exogenous parts shows that cost interactions between the equipment in this hybrid system is not strong. Heat exchangers investment cost and exergy destruction cost are avoidable and unavoidable respectively, while opposite behavior is exhibited by the compressors. From avoidable exergy destruction cost point of view, compressor C-1 and from avoidable investment cost point of view, heat exchangers have high improvement potential. Also effects of key parameters on the exergoeconomic factor and exergy destruction cost rate are studied through the sensitivity analysis. Finally, three strategies are recommended for removing the inefficient costs and improving the system performance.