Energy and exergy analysis of a proton exchange membrane water electrolysis system without additional internal cooling

Abstract

A new PEMEC system without integrated cooling channels inside the PEMEC stack is analyzed in this paper. An external energy source is integrated into the heat exchanger to control the stable operation of the system. Based on the balance of charge, mass and energy, the models of both the stack and the system are established. The influences of operating parameters, such as inlet water flow rate, inlet water temperature and current density, on the PEMEC stack performance are investigated, and the energy efficiency and exergy efficiency of the PEMEC system under both the heat dissipation condition and the adiabatic condition are discussed. The results show that the purpose of keeping the operating temperature of the stack can be achieved by regulating the inlet water temperature and flow rate. A relatively good operating mode is a low inlet temperature, an insulated stack and a current density in range of 1.0 and 2.0 A/cm2. The present work can provide some guidances for the optimum design of the PEMEC system.