质子交换膜燃料电池建模及水热传输特性分析

针对质子交换膜燃料电池(PEMFC)水管理开展了研究,建立了一维非等温两相流解析模型,研究了不同电流密度、微孔层接触角和不同加湿方案对电池内部水分布和温度分布的影响,提出了更好的进气加湿方案。结果表明:电流密度增大会导致阳极拖干、阴极水淹加剧,导致电池各部分温度上升。因各层材料亲水性不同,在交界面处能观察到液态水阶跃现象。增大微孔层接触角促进阴极液态水反扩散到阳极,一定程度上缓解阳极变干,但过大的接触角可能导致阴极水淹加剧。通过采取"阳极充分加湿、阴极低加湿"的进气加湿方案可以有效提高电池性能,并且能在一定程度改善电池内部受热,提高电池使用寿命。

Modeling and analysis of water and heat transfer characteristics of proton exchange membrane fuel cell

Water management of proton exchange membrane fuel cell (PEMFC) was studied, and a one-dimensional non-isothermal and two-phase flow model was built analytically. The effects on water and temperature profile inside the fuel cell were studied under conditions of different current density, contact angle of microporous layer (MPL) and humidification schemes. The results indicate that the increase of current density will exacerbate dehydration in anode and water flooding in cathode, which leads to temperature rise in each part of the fuel cell. Water saturation jump is observed at the interface of adjacent layers with different wettability. Larger contact angle of microporous layers (MPL) facilitates liquid water to transport from cathode to anode through back diffusion process, relieving the dehydration of anode to some extent. However, excessive increase of MPL contact angle may worsen the flooding of cathode on the other hand. With fully humidified anode and low-humidified cath-ode, the fuel cell performance is comparatively improved due to the alleviated flooding of cathode. In addition, this inlet humidification scheme turns out to improve the internal heat condition, which may increase the lifetime of the fuel cell.