Thermodynamic Analysis of a Novel Combined Hydrogen Fed Solid Oxide Fuel Cell - GAX Absorption Refrigeration Cycle

A new combined cogeneration cycle producing power and cooling is proposed and analyzed in detail. The cycle is a combination of hydrogen fed solid oxide fuel cell (SOFC) and an ammonia water generator- absorber- heat exchanger (GAX) absorption refrigeration system. Using the Engineering Equation Solver (EES), the solution to the electrochemical and thermodynamic equations simulates the cycle performance. The results show that for the same condition, the energy and exergy efficiencies of the proposed cycle is 68.2% and 5.88% higher than those of the stand-alone fuel cell, respectively. The net produced power and cooling as well as the input hydrogen mass flow rate increase with rising the current density, so that the energy efficiency increases and the exergy efficiency decreases. Optimization is also performed for the proposed cycle and it is observed that both the net produced power and exergy efficiency are maximized at some pressure ratio and fuel cell operating temperature. The results indicate that the air pre- heater contributes the most in the cycle irreversibility.