空冷型质子交换膜燃料电池阴极供气模式研究

Study on cathode air feeding modes of air-cooledproton exchange membrane fuel cell

基于自制的空冷型质子交换膜燃料电池建立了阴极风机系统仿真模型,验证了该模型的准确性。利用该模型研究了风机系统工作在吹气、吸气和导流3种供气模式对电堆阴极气流及温度的分布影响。研究结果表明:在吹气模式下燃料电池电堆阴极气流分布均匀性较差,原因在于风机出口气流存在边界层分离,分离的低速气流在轮毂形成回流,影响了下游气流的分布均匀性;吸气模式和导流模式可有效提升电堆阴极气流分布均匀性,改善电堆局部换热性能。当风机转速为25 000 r/min时,吹气模式、吸气模式和导流模式下工作的电堆最大温差分别为7.9、5.4、6.5℃,说明吸气模式下工作的电堆温度分布更均匀。

In this article,based on the self-made air-cooled proton exchange membrane fuel cell,a simulation model of the cathode fan system is presented,and then it is validated for the accuracy of the model by experiments.With the model built,the influence on the air flow and temperature distribution with three air feeding modes,like blowing mode,suction mode and diversion mode,for fan system is studied.As a result,it shows that the air flow distribution uniformity of cathode outlet is poor when it works in the blowing mode,the reason for this is the boundary layer separation at the outlet of the fan,and the separated low-speed gas flow forms a backflow in the hub,which affects the distribution uniformity of the downstream gas flow;both suction mode and diversion mode can effectively improve the uniformity of the cathode air flow distribution of the stack and enhance the local heat transfer performance of the stack.At the fan speed of 25000 r/min,the maximum temperature difference of the stack operating in the blowing mode,suction mode and diversion mode is 7.9℃,5.4℃and 6.5℃,respectively,it illustrates that the temperature distribution of the stack operating in the suction mode is more uniform.