Experimental Study On Icing Characteristics And Local Heating Method Of PEMFC Cold-start

Proton exchange membrane fuel cells,as an important vehicle power source in the future,have been initially commercialized in Japan.However,it still has the problem of starting in a cold environment,and it is urgent to develop a low-cost cold start method that is simple,fast,effective,energy-saving,and adaptable.That membrane electrode,the core component of fuel cell,has rapid rise of temperature is important to the success of cold-start.Based on the research on the icing characteristics of fuel cell membrane electrodes,a local heating cold starting scheme is proposed.The main content of this paper has three parts: the first part introduces the fuel cell experiment systems,carries out the reproducibility experiment of normal temperature performance and cold start performance of fuel cell,and studied the effects of various factors on the normal temperature performance of fuel cells;the second part studies the effects of starting temperature,current density,fuel cell assembly pressure,microporous layer hydrophobicity,flow channel width and other factors on the icing and cell performance of the membrane electrode during cold start;the third part mainly studies the local heating cold start experiment of fuel cell under different environmental temperature,current density,number of heating wire and cell insulation degree,and tests the corresponding changes of voltage,impedance and gas diffusion layer temperature.First,in the current cold start study,there are few studies on the icing characteristics of fuel cells.In addition,most of the research focuses on heating the cooling medium to increase the fuel cell temperature,which not only causes waste of thermal energy but also prolongs the cold start time.The additional heat source device adopts a large volume and can not reduce the use cost.Therefore,this paper first studies the icing characteristics of the fuel cell during cold start in the direction of the reaction area.It is found that icing during cold starting when the fuel cell temperature was higher than-10 ? mainly occured at the interface between the catalytic layer and the microporous layer,the ice between the interfaces was mainly distributed in the corresponding area under the flow channel;the greater the assembly pressure,the less the ice content at the two interfaces,the better the cold start performance;the narrower the width of the flow path,the longer the fuel cell began to freeze;the fuel cell using the microporous layer of weak hydrophobicity was once frozen at-5 ?,and the fuel cell using the microporous layer of strong hydrophobicity wasconcentrated twice at-5 ?.Then,for the icing characteristics of the above fuel cell during cold start,a local heating cold start scheme in which the heating wire is placed under the ridge is proposed.The experimental results show that the local heating method could effectively increased the temperature rise rate and formed a local high temperature zone in the fuel cell to achieve a successful cold-start.In addition,when the average heating power density was the same,the fuel cell useing one heating wire had better cold starting effect than ones using three heating wires.