Study On Key Technologies Of PEMFC

Proton exchange membrane fuel cell (PEMFC)as a new type of electrochemical power generation device, breaks the traditional power generation mode.Fuel cell directly transfers chemical energy stored in the fuel and oxidizer into electricity through electrochemical reaction efficiently and environment-friendly.due to PEMFC’s advantages of low operating temperature, high power density, quick response speed, good stability it has a very broad application prospects in the field of distributed power station, portable mobile power andnew energy vehicles.This paper mainly focuses on differences on the influences of humidity of cathod and anode on the performance of PEMFC for air-cooled PEMFC, the coupling management of fuel cell and metal hydrogen storage,shut-down strategy of fuel cell and The main results of research are as follows:(1) The relative humidity of cathode and anode gas affects the conduction of the water and the transmission rate of proton exchange membrane. A appropriate humidity of cathode and anode gas helps to improve and enhance the performance of the fuel cell. In this paper, a numerical simulation model of a proton exchange membrane fuel cell with single straight channel was established in order to study on the influence of reactants humidity on the performance of PEMFC, laying foundation for searching the best humidityof the cathode and anode gas.(2) Based on air-cooling PEMFC test system, studies on thermally coupled management about metal hydrogen and fuel cell are conducted. Research on two different coupling modes between fuel cell and mental hydrogen storage(respectively putting mental hydrogen storage in the front and rear) verify a new thermally coupled structure for fuel cell and metal hydrogen storage. This coupling structure consideres the influence of environmental temperature on the fuel cell system. Therefore, most suitable structure can be selected according to environment temperature and allows the fuel cell system to operate in the high-efficiency region all the time.(3) The unbalanced consumption of residual gas could easily lead to reverse polarization of single cell during the process of shuting down using constant auxiliary load. To avoid this phenomenon, this paper presents two different shutdown strategies which taking consideration of the voltage balance.These two strategies shorten the duration time of monocel in high potential significantly and simultaneously avoid the forementioned phenomenon of unbalanced consumption of residual gas and also the subsequent consequnces, improving the voltage balance of the single battery.