【作者】 秦明俊；

【导师】 于立军；

【作者基本信息】 上海交通大学 ， 热能工程， 2009， 硕士

【摘要】 质子交换膜燃料电池(PEMFC)应用前景广阔,市场潜力巨大,对产业结构升级、环境保护及经济的可持续发展均有重要意义。PEMFC工作过程涉及电化学反应、气体多组分传输、热传递、多孔介质渗流和气液两相流动等多种耦合在一起的复杂的物理化学现象,而且由于燃料电池的复杂结构和尺寸限制,实验数据不易测得。因此,数值模拟仿真技术作为实验技术的必要补充变得非常关键。本文采用一个全面完整的PEMFC三维、两相、稳态、非等温的数学模型进行了模拟分析。该模型综合考虑了电化学反应动力学以及反应气体在流道和多孔介质内的流动和传递过程、电流的传输、热量的传递、水在质子交换膜内的电渗和扩散以及两相流动。模拟的区域包括阴阳极集流板、阴阳极半个流道、阴阳极气体扩散层和催化层、以及质子交换膜。首先利用计算流体力学软件FLUENT和其UDF功能进行电池全场的数值模拟,通过与文献中所公布的实验数据进行对比来验证模型的准确性。该模型能够更全面地反映燃料电池内部的传输现象以及准确地描述电池工作性能。基于该模型通过数值模拟全面分析直流道PEMFC内不同工况下的相关传输现象,得到了电池内部详细的反应物的传输、水的传递、电流的传输以及速度和温度的分布。对PEMFC的一些性能影响因素进行详尽的模拟分析,包括扩散层孔隙率、工作温度、工作压力以及阴阳极的增湿温度。更多还原

【Abstract】 Proton exchange membrane fuel cell (PEMFC) has broad applications and great potential of market. It is of much significance for industrial upgrading, environmental protection, and sustainable economic development. PEMFC’s operation process includes electrochemical reactions, species transport, heat transfer, flow in porous media, and gas-liquid two-phase flow, etc. These complex physical and chemical phenomena are tightly coupled. Besides, the experiment data is hard to obtain due to the complexity of fuel cell structure and the limitation of the scale of fuel cell. Therefore, the numerical simulation technology as a necessary complement to experimental techniques becomes very critical.In this paper, a comprehensive and complete three-dimensional, two-phase, steady-state, non-isothermal fuel cell model was used for the simulation analysis. The model took into account the electrochemical reaction kinetics, the reactant transport process in the flow channel and porous media, current transfer, heat transfer, and two-phase flow, as well as water transport in the proton exchange membrane due to the electro-osmosis and diffusion. The simulation region included plates, half of flow channels, and gas diffusion layers and catalyst layers at anode and cathode, as well as the proton exchange membrane.First of all, the numerical simulation of the whole fuel cell was performed using computational fluid dynamics (CFD) software FLUENT and its UDF functions. The accuracy of the model was verified by comparing experimental data published in literature. The model can comprehensively reflect the transport phenomena within the fuel cell, and accurately predict the cell performance.Through the numerical simulation of the model, the comprehensive analysis of PEMFC with straight flow channel under different operation conditions was conducted and the relevant detailed transport phenomena have been obtained, including the reactant transport, water delivery, electron transmission, and the distribution of velocity and temperature. Some factors which can influence the PEMFC performance were studied through a detailed simulation analysis, including diffusion layer porosity, operation temperature, and operation pressure, as well as cathode and anode humidification temperature.更多还原