Fuel cell vehicles have been paid more and more attention, while the low temperature cold start capability has become the main reason that hinders their large-scale commercialization, especially for the fuel cell bus. Generally, liquid heating (positive temperature coefficient thermistor (PTC) as the heat source) and fuel cell self-starting heating are the common cold start methods. However, these methods can bring about low start speed and high energy consumption. Therefore, a new cold start method combined with liquid heating and fuel cell self-starting is proposed to solve the problems. Besides, phase change material (PCM) is introduced to reduce energy consumption further. The PCM can absorb the waste heat of the fuel cell stack. Then the heat can be used for stack cold start by circulating liquid. In this study, a fuel cell bus cold start system simulating model is built. Based on this model, the fuel cell temperature and energy consumption during the cold start are analyzed. The results show that the method combined with liquid heating and fuel cell self-starting is superior to the liquid heating method. The cold start time and PTC consumption of the PTC-PCM-self-starting heating mode are 19.0 % and 19.2 % less than that of PTC-PCM heating mode. As for the combined heating method, dropping the self-starting temperature can not only increase the cold start speed but also reduce the proportion of electric heating. For every 1 °C decrease, the start-up time is shortened by 1 % on average, and the waste heat utilization rate is increased by 0.5 %. Although increasing the self-starting current can increase energy consumption, it will save more cold start time and reduce the proportion of electric heating. For every 1 A increase, the start-up time is shortened by 0.3 % on average, and the waste heat utilization rate is increased by 0.1 %. The PTC-PCM-self-starting heating method provides a way for fuel cell stack to start quickly and energy-efficiently in low temperature environment.

中文翻译：

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燃料电池堆冷启动结合液体加热及燃料电池自启动研究


燃料电池汽车越来越受到重视，而低温冷启动能力成为阻碍其大规模商业化的主要原因，尤其是燃料电池客车。一般来说，液体加热（正温度系数热敏电阻（PTC）作为热源）和燃料电池自启动加热是常见的冷启动方式。但这些方法都会带来启动速度慢、能耗高等问题。因此，提出一种液体加热与燃料电池自启动相结合的新型冷启动方法来解决该问题。此外，引入相变材料（PCM）进一步降低能耗。 PCM可以吸收燃料电池堆的废热。然后热量可以通过循环液体用于堆冷启动。本研究建立了燃料电池客车冷启动系统仿真模型。基于该模型，分析了燃料电池冷启动时的温度和能耗。结果表明，液体加热与燃料电池自启动相结合的方法优于液体加热方法。 PTC-PCM自启动加热模式的冷启动时间和PTC消耗量分别比PTC-PCM加热模式减少19.0%和19.2%。对于组合加热方式，降低自启动温度不仅可以提高冷启动速度，还可以减少电加热的比例。每降低1℃，启动时间平均缩短1%，余热利用率提高0.5%。增大自启动电流虽然会增加能耗，但会节省更多的冷启动时间，减少电加热的比例。每增加 1 A，启动时间缩短 0。平均提高3%，余热利用率提高0.1%。 PTC-PCM自启动加热方式为燃料电池堆在低温环境下快速节能启动提供了途径。