空冷PEMFC空气流向实验研究

Study of air flow direction of air-cooling PEMFC

空冷型质子交换膜燃料电池利用外部风扇来提供反应所需空气,并为电堆散热。由于电堆内部流道以及外部风扇罩的影响,空气的流向不同会对电堆内部空气在各单电池间的流动造成影响,从而影响电堆内的冷却和电化学反应效果。开展了空气的流向对电堆性能影响的实验研究,在环境温度、风扇转速等外界条件不变的情况下,测量了散热风扇"吸风"与"吹风"两种空气流动方式对电堆和各单电池输出特性的影响。结果表明,采用"吸风"方式供应空气(即正向流动)时,虽然电堆总体性能略低于"吹风"(即反向流动),但电堆均匀性和稳定性要更好,因此在空冷型质子交换膜燃料电池的使用过程中,采用空气正向流动方式更有利。

Extemal fans are used in air-cooling PEMFC to provide the needed air for reactions and dissipate heat for the stack.Because of the effect of the intemal flow passage of stack and extemal fans,air flow through the single cells will be different for different flow directions,affecting the cooling effect and the electrochemical reaction in the stack.The performance of the fuel cell stack under different air flow directions was studied by experiments with unchanged extemal conditions such as ambient temperature and the fan speed.The output performance of each single cell under two air flow ways including ＂absorbing wind＂ and ＂blowing wind＂ was measured.The experimental results show that the uniformity and stability of the stack under positive air flow are much better than the reverse flow,although the stack overall performance is a little bit lower.Therefore,the forward air flow direction is recommended during using air-cooling PEMFC.