Restarch On Performance Of Air-Cooled Pemfc Under Different Environmental Conditions

Proton exchange membrane fuel cell (PEMFC) is a novel electrochemical power generation device, which breaks the traditional modes of generation. The energy in the fuel and the oxidant can be directly transferred into electricity through the stacks in an efficient and environmental manner. It has a wide range of applications, and the air-cooled PEMFC is mainly used in low-power occasions, which has a pursuit of most simplified system. However, the simple system making it very sensitive to changes of the external environment. The changes of the environmental temperature and humidity have a significant impact on the PEMFC’s output performance and optimal operating temperature points.The control strategy of the PEMFC under different environmental conditions is researched in this paper, and the main achievements are summarized as follows:(1) Build an air-cooled PEMFC test system. The proper air flow direction was obtained after comparing the stack’s output voltage and the output of each single cell. The simulation was used to verify the conclusion above. PEMFC can benefit a lot when operating under correct air flow direction, such as extend its life and improve the uniformity of single cells.(2) Using environmental chamber to simulate environmental conditions. Firstly, set different stack currents, and select a number of different temperature and humidity points: secondly, mapping the output voltage with the stack temperature curve; thirdly, search the optimum operating temperature points from the figures above. The results show that changes in environmental temperature and humidity affected both the output voltage and the best operating temperature points.(3) According to the best operating temperature points under different environmental conditions, with environment humidity, environment temperature and output current as independent variables, and with the optimal operating temperature as the dependent variable, fitting out an empirical formula. The regularity which the stack optimum operating temperature points with the variation of environmental change was investigated according to the empirical formula. And the validity of the formula was verified through the experiments at last. It is also laid a good foundation for the next control work.The results of this paper have a certain sense for extend the life of air-cooled PEMFC. And the empirical formula provides us a convenient mode to get the best output voltage we want, and it also provides a strong reference for the next optimal control work.