Development of a combined system based on a PEMFC and hydrogen storage under different conditions equipped with an ejector cooling system

Abstract

In the current work, thermodynamic examination for cogeneration of electricity and cooling based on a polymer exchange membrane (PEM) fuel cell was carried out. To the waste energy in the fuel cell, an absorption refrigeration unit is employed in two modes with ejector and without ejector. This system includes a PEM-FC, an absorption refrigeration unit, a hydrogen storage tank, an ejector, and an air compressor. The produced thermal energy in the fuel cell is received entirely by a working fluid and is given to the absorption chiller generator. The system simulation was carried out from two perspectives of energy and fuel saving. Findings showed that the energy efficiency of the combined cooling and power (CCP) unit and the CCP system equipped with the ejector (CCP-E) was 63.72% and 78.33%, respectively. It indicated that adding the ejector to the system increases the energy efficiency of the system by 23%. The fuel economy percentages of the CCP system and CCP-E were 44.43% and 45.9%, respectively. The results also showed that adding the ejector in the refrigeration system increases the system performance by up to 44%. The presence of the ejector causes the working fluid flow in the evaporator to increase with the suction of the secondary flow, and the cooling capacity increases significantly. Moreover, with increasing generator and evaporator pressure, the suction ratio of the cooling system equipped with the ejector decreases and increases, respectively.