车用质子交换膜燃料电池交变温度条件下的膜电极受力分析

Stress Analysis of Membrane Electrode Assembly of Automotive Proton Exchange Membrane Fuel Cell under Alternating Temperature Conditions

为了研究车用质子交换膜燃料电池实际工作过程中膜电极所受温度应力及其对膜电极物理耐久性的影响,首先通过整车动力系统模型仿真研究了外负载变化条件下蓄电池容量对电堆输出功率波动的影响,利用燃料电池热力学模型仿真得到电堆功率波动条件下燃料电池工作温度的波动情况,并导入有限元仿真模型,分析膜电极内部温度应力变化情况。由仿真结果可知,膜上微裂纹端部在温度作用下会出现集中应力,且裂纹在膜电极中的延展是逐渐加速的过程。在环境箱中对膜电极样件进行了温度循环加载试验,验证了温度应力仿真所得结论的正确性。

In order to study the thermal stress of Membrane Electrode Assembly(MEA)in the actual working process of automotive Proton Exchange Membrane Fuel Cell(PEMFC)and its influence on physical durability of MEA,firstly a vehicle power system model is established to simulate and study the influences of storage battery capacity on cell stack output power fluctuation under the condition of external load changes,fuel cell dynamical model simulation is conducted to obtain the fluctuation of fuel cell working temperature under the function of cell stack power,and then fuel cell dynamical simulation data is imported FE simulation model to analyze the fluctuation of internal temperature and stress of MEA.The simulation results show that the microcrack end on the MEA will produce concentrated stress under the temperature effect,and the crack extending on the MEA shows a gradually accelerating process.Temperature cycling loading test is carried out for the MEA samples in the environment cabinet,verifying accuracy of the conclusion of the temperature stress simulation.