Energy and exergy analyses of a novel hybrid system consisting of a phosphoric acid fuel cell and a triple-effect compression–absorption refrigerator with [mmim]DMP/CH3OH as working fluid

Abstract

Energy and exergy analyses were conducted on a proposed hybrid system consisting of a phosphoric acid fuel cell (PAFC) and a triple-effect compression–absorption refrigerator with [mmim]DMP/CH3OH as working fluid (HFCAR). The HFCAR system was modeled and simulated based on the current density model of PAFC, isentropic efficiency model of assisted compressor, and mass and energy conservation model of the compression–absorption refrigerator. For the basic design condition, the detailed operating parameters of each status point, energy conservation, temperature difference, and total thermal conductance of each component were simulated and discussed. For the variable conditions, the effects of electrical current density, PAFC temperature, and compression ratios on 16 key operating parameters were simulated and analyzed. A critical electrical current density was proposed. Under condition of critical current density, HFCAR system works as a cooling system with the largest cooling capacity. The variation characteristics of the critical electrical current density were studied. The exergy losses of each component were simulated and analyzed. The PAFC efficiency and heat transfer characteristic of certain components should be optimized to improve the thermal performance of the HFCAR system.