Energy, exergy and economic analysis of an improved Kalina cycle integrated with a proton exchange membrane fuel cell

Integrating a PEM fuel cell with an improved Kalina cycle to gain more electrical power is presented in this study. The Kalina cycle consists of two turbines and two separators. The waste heat of the PEM fuel cell is the major energy source for the Kalina cycle and industrial waste heat is supplied to the cycle to generate more electrical energy. Thermodynamic and exergoeconomic analysis is carried out on the system components to evaluate the system performance. The results indicate that the proposed system can produce 14.51 % more power in comparison with the standalone PEM fuel cell, while the total cost rates of the system increase by 19.3 %. Moreover, the energy and exergy efficiencies of the proposed hybrid system is 5.01% and 14 % higher than the energy and exergy efficiencies of the standalone PEM fuel cell. The exergoeconomic analysis shows that the fuel cell, the turbines, the compressor and the condenser have the highest cost rates compared to other components of the system. Furthermore, a parametric study is performed on the system to investigate the effect of variations of some key parameters, including PEM fuel cell operating temperature and pressure, current density, ammonia mass fraction and maximum pressure of the Kalina cycle on system performance.