Integrated Kalina cycle in a combined polymer membrane fuel cell and evacuated heat pipe collector for a new power generation system

This paper presents the integration of the Kalina cycle process in a combined polymer membrane fuel cell and evacuated heat pipe collector for improvement of power generation efficiency. The proposed system is evaluated from thermodynamic, environmental, and exergoeconomic perspectives, and the effect of key system parameters are investigated. The energy and exergy efficiencies of the proposed system in the given conditions are improved by 13.12% and 10.35%, respectively compared to an independent fuel cell. The system's product unit cost of the system and output power in this condition are 136.1 $/GJ and 145.1 kW. The system also prevents the production of 116.1 kg/hr of carbon dioxide under these conditions. The analysis of system parameters shows a direct relationship between increased current density, temperature, and operating pressure of the fuel cell and decreased energy and exergy efficiencies. On the other hand, the total product unit cost increases as these parameters increase. The system assessment shows there is a suitable turbine inlet pressure to achieve optimal efficiency, the lowest unit price for the product, and maximum CO2 emission reduction. Although solar collectors reduce the system's energy efficiency, they increase the exergy efficiency and reduce the cost per unit of the total product.