Thermodynamic and exergoeconomic analyses of a proton exchange membrane fuel cell (PEMFC) system and the feasibility evaluation of integrating with a proton exchange membrane electrolyzer (PEME)

Abstract

Fuel cells offer one of the most eco-friendly and efficient ways of energy production. In this study a thermodynamic and exergoeconomic assessment of a proton exchange membrane fuel cell (PEMFC) system at steady-state operation condition are carried out. Thereafter, the feasibility of integrating a proton exchange membrane Electrolyzer (PEME) to supply required fuel for a PEMFC, operating in the same outlet power range is investigated. The results demonstrate that increasing the current density rises the following parameters in the system: the power and power density rates of the PEMFC and PEME, the exergy destruction rate of each component, the hydrogen production and consumption rates in the cycles, the PEME output voltage, cost rate of power generation and the power cost of the PEMFC. By increasing the PEMFC output voltage, the energy and exergy efficiencies reduce. Moreover, rising the outlet temperature of the PEMFC increases the power and power density rates of the PEMFC and also the energy and exergy efficiencies of the system. While increasing the outlet and operating temperature of the PEME increases the power consumption rate and reduces the energy and exergy efficiencies. The highest energy efficiency of the PEMFC is 36.7% and corresponding maximum exergy efficiency is found 54%, while the lowest values are found 31% and 45.3%, respectively. The cost rate of the power generation by PEMFC is varied between 7.96 × 10−4 and 1.33 × 10−3 $/s and the corresponding rate of the exergy unit cost range is 115.6–132.2 $/GJ.