Analysis of a hybrid system combining solar-assisted methanol reforming and fuel cell power generation

The proton exchange membrane fuel cell (PEMFC) is an efficient and clean power unit that has become a research hotspot for scholars around the world, but the hydrothermal management of the PEMFC limits the cell performance and hinders its large-scale application. In the paper, a hybrid system combining solar-assisted reforming of methanol and fuel cell power generation is proposed, in which methanol is used as a coolant in the hydrothermal management of the PEMFC subsystem to take away the waste heat, and further reformed for hydrogen production with the assistance of the solar energy subsystem to improve the hybrid system efficiency. The study is carried out at both the single cell level and system level to investigate the effect of solar energy on the performance of the hybrid system by simulation results, which are obtained from the finite element software, such as the performance of the PEMFC. The results show that the novel hydrothermal management method using methanol and water in the single cell can control the temperature at 60–80 °C. The highest power density of the single cell reaches 0.595 W/cm² at a water-to-alcohol ratio of 1:1 and a coolant flow rate of 2.846 mol/s. In addition, the exergy of this hybrid system improves by 76.36% compared to the exergy of the solar thermochemical methanol reforming system at a reaction temperature of 200 °C when the methanol reforming reaction is more complete. The system efficiency can reach up to 59.15%, compared to the solar thermochemical methanol reforming system and the methanol reforming system heated by combustion of methanol, which can only reach 51.10% and 43.18%, respectively. This study provides a novel method for addressing the hydrothermal management issue of PEMFC and a new idea for the efficient utilization of solar energy.