车用燃料电池效率测试及影响因素

Testing and influencing factor for efficiency of vehicular fuel cell

燃料电池具有效率高、运行时无污染的特点,成为新能源汽车的首选动力源。为了更好地利用其能量转换效率高的特点,需要考察燃料电池的效率随工作条件变化的特性。本文根据车用燃料电池的工作原理,以某国产500 W氢/空燃料电池为核心,构建测试平台,建立了燃料电池效率的测试计算方法。通过试验得到的结果表明:反应气压力对电池的效率影响较显著。电池效率在最大工作功率的30%以前随功率的增加而快速增大,达到最大效率点以后随着功率的继续增加效率缓慢下降,在达到最大工作功率的约70%～80%以后,下降梯度略有增大。在最大效率点之前,燃料电池效率随反应气体压力的增加而显著增大;在最大效率点之后随着电池输出功率的增加,反应气体压力对电池效率的影响逐渐减小。测试结果还表明,电池温度和反应气增湿温度对燃料电池效率影响较小。讨论了提高车用燃料电池系统能源效率的途径。

Because of high efficiency and no-pollution on working time,fuel cells became preferred new power in automobiles.For better use of the high energy conversion efficiency of fuel cells,characteristic of efficiency of fuel cells with working conditions had to be investigated.Based on working principle of vehicular fuel cells,a domestic 500 W hydrogen/air fuel cell was used to construct a testing platform and a formula of fuel cell efficiency was developed.Testing results indicate that the reactant gas pressure has remarkable impaction on fuel cell efficiency and efficiency increased markedly before reaching rating power of 30%.After that,efficiency decreased tardily until reaching rating power of 70% to 80%.Then,the descent gradient of efficiency increased a little.Before reaching peak value of fuel cell efficiency,fuel cell efficiency increased markedly along with increasing of reactant gas pressure.After that,effect of reactant gas pressure on fuel cell efficiency decreased gradually along with increasing of output power.Meanwhile,temperature and humidifying temperature of fuel cell had little impaction on fuel cell efficiency.Means to improve energy efficiency of fuel cell hybrid system were discussed.