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Proton exchange membrane fuel cell (Proton Exchange Membrane Fuel Cell, PEMFC), also known as a solid polymer fuel cell (Solid Polymer Fuel Cell, SPFC), low noise, pollution-free, low temperature start-up and high energy conversion, etc., are widely used in aviation aerospace, transportation and medical fields. With the intensification of the energy crisis and environmental problems growing increasingly obvious importance of PEMFC. The main direction of development of PEMFC power supply, an important indicator of research output performance of the civil power, small power stations. The purpose and significance of this study is to identify the fuel cell to affect the relationship between the factors and output characteristics, improve the output performance of the PEMFC improve the basis for the optimal design of the fuel cell. First, by analyzing the the PEMFC output characteristics influencing factors, the impact of factors or parameters are divided into two categories: a class of control factors, including temperature, humidity, pressure and flow; another non-controlling factors, mainly including the model factors material factors, structural factors and mass transfer factors. Thesis under the guidance of instructors static PMEFC output performance evaluation: the current density range D (the smaller the better) and the output voltage static error rate of S (the bigger the better). At the same time, for example to verify the validity of the evaluation of the performance. Secondly, the use of the knowledge of the kinetics and thermodynamics of the electrode reaction, the establishment of the main influencing parameters, such as the area of the proton exchange membrane, the thickness of the proton exchange membrane, the temperature of the battery operation, hydrogen and oxygen pressure, etc., and the battery output performance between the mathematics model. And use MATLAB simulation research within the the PEMFC different current density region of the main factors. The research results show that the the major effects affect the magnitude of the output parameters of the battery performance is different, but all have one-way. Again, based on the mathematical model between the main factors and output performance, within a certain period of time in the the PEMFC operating environment under set by random changes in the main influencing parameters. Apply a fixed current, and changes in current are two ways for simulation and analysis of the output performance of the fuel cell to obtain a fixed current of the optimal combination of parameters: The water content was 18.17, and the operating temperature is 368.14K hydrogen pressure of 1.819atm, oxygen pressure change current optimal combinations of parameter values 1.279atm;: water content of 14.12, the operating temperature of 366.41K, hydrogen pressure 1.655atm, oxygen pressure 1.592atm. Finally, through a comprehensive three-dimensional geometric model of the reaction electrochemistry, fluid model, mass transfer and heat transfer principle, the establishment of a DC single channel numerical model. Different geometry on the performance of fuel cell output: the geometrical dimensions of the battery output performance, established different flow channel model: Shoulder geometric model and the depth of the flow channel geometry model. And optimal Shoulder geometric model of the flow channel, by changing the porosity of the catalytic layer to study the impact of porosity on the output performance of the PEMFC. Use FLUENT simulation study of the geometrical parameters, the derived geometric parameters of the optimal value: Shoulder 1:1, and a catalytic layer with a porosity of 50%, the depth of the flow path is 0.4mm.
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