两种不同结构质子交换膜燃料电池的性能分析

Performance Analysis of Two Proton Exchange Membrane Fuel Cells with Different Structures

双极板(bipolar plates)在燃料电池中起到传递电能和热能以及分配和分离反应气体的作用,是质子交换膜燃料电池的重要组成部件。通过CFD技术将平行流场和单蛇形流场燃料电池的性能进行仿真分析,比较两种不同流场的燃料电池的反应流体速度分布、反应物氢气分布和压力云图,分析流场分布对燃料电池性能的影响。分析得出:平行流场反应流体压降小,电化学反应更稳定,但反应流体分布不均,供气量不足,易造成水淹现象;蛇形流场流道长度长,压降大,反应流体流动速度快且分布均匀,能够避免水淹现象,但压力损失大,电流密度分布不均,不利于燃料电池性能发挥。

Bipolar plate is an important component of proton exchange membrane fuel cell(PEMFC),which can transfer electric energy and heat energy,distribute and separate reactive gas.The performance of fuel cells with parallel flow field and single serpentine flow field was simulated and analyzed by CFD technology.The velocity distribution of reaction fluid,hydrogen distribution of reactant and pressure nephogram of fuel cells with two different flow fields were compared to analyze the influence of flow field distribution on the performance of fuel cells.The results show that the pressure drop of reaction fluid in parallel flow field is small and the electrochemical reaction is more stable,but the distribution of reaction fluid is uneven and the gas supply is insufficient,which is easy to cause water flooding.The serpentine flow field has the advantages of long channel length,high pressure drop,fast flow speed and uniform distribution of reaction fluid,which can avoid water flooding.However,the large pressure loss and uneven distribution of current density are not conducive to the performance of fuel cells.