基于金属氢化物固态氢源的氢燃料电池动力系统特性的研究

The hydrogen fuel cell technology has been increasingly developed in recent years due to its advantages of clean utilization, high efficiency and free-pollution. Thus, hydrogen fuel cell technology is regarded as one of the most promising power generation systems in the future. In the practical applications of hydrogen fuel cell technology, an efficient, safe and economical hydrogen storage method is remarkably crucial for promoting large-scale utilization of hydrogen fuel cell technology. Among all the hydrogen storage methods, the solid-state hydrogen storage method has been extensively reported to be the promising candidate for hydrogen storage due to its advantages of high hydrogen storage capacity, good hydrogen absorption/desorption reversibility, moderate hydrogen absorption/desorption plateau pressure, low price and good safety. Metal hydride, as the well-known hydrogen storage material, has been successfully applied in the fields of heat pump, hydrogen compression and polygeneration. In this work, the solid-state hydrogen storage reactor based on metal hydride was designed and integrated with the proton exchange membrane fuel cell (PEMFC) to form a highly efficient and high volumetric density power generation system. Specifically, an experimental platform of the fuel cell power system with a nominal output power of 20 W was developed and used to investigate the effects of various key operating parameters including hydrogen absorption pressure, dehydriding temperature and the hydrogen flow rate after dehydriding on the hydrogen fuel cell system’s output. The results showed that a stable hydrogen flow rate after dehydriding could be maintained for up to 4500 s when the hydrogen absorption pressure was at least 0.60 MPa. Moreover, a higher hydrogen flow rate resulted in higher power generation from the fuel cell power generation system. When the dehydriding temperature was more than 60℃, the metal hydride hydrogen storage reactor enabled a complete release of the stored hydrogen. However, further increased in the dehydriding temperature had little contributions to facilitating the dehydriding reaction. In addition, lower hydrogen flow rates which were still over the required flow input into the PEMFC resulted in longer working time of the fuel cell power generation system.