Enhancing energy efficiency through combined PEMFC and MH systems and advanced exhaust management strategies

Proton Exchange Membrane Fuel Cells (PEMFC) generate substantial heat during operation. This heat constitutes over 40% of the total energy produced from the cells' hydrogen fuel, making reusing this energy a focal point of research. An innovative system integrating PEMFC with Metal Hydrides (MH) was introduced. It utilizes the waste heat from the PEMFC to enhance hydrogen release from the MH, thereby improving overall energy efficiency. Two exhaust management strategies and experimental methods were designed to evaluate their impact on PEMFC operational efficiency and the hydrogen desorption rate from MH tanks. Temperature, pressure, and hydrogen flow rates were measured across various configurations. The results indicate that these strategies significantly stabilize operating temperatures and mitigate pressure drops. Additionally, under the new plan, the waste heat discharge rate increased from a baseline of 8.8%–10.4%, and then to 14.4%, demonstrating a marked improvement in thermal efficiency. The effective absorption rate of waste heat discharged by the FC into the MH tanks reached 8.3%, leading to a significant 13% increase in the hydrogen release rate. These improvements emphasize the effectiveness of the proposed strategies in alleviating temperature and pressure fluctuations while significantly enhancing the system's overall energy utilization.