Modeling gas flow in PEMFC channels: Part I – Flow pattern transitions and pressure drop in a simulated ex situ channel with uniform water injection through the GDL
Modeling gas flow in PEMFC channels: Part I – Flow pattern transitions and pressure drop in a simulated ex situ channel with uniform water injection through the GDL
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DOI：
10.1016/j.ijhydene.2012.06.001
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发表时间：
2012-09
影响因子：
7.2
通讯作者：
M. Grimm;Evan J. See;S. Kandlikar
中科院分区：
文献类型：
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作者：
M. Grimm;Evan J. See;S. Kandlikar
采用气体扩散层（GDL）作为质子交换膜燃料电池（PEMFC）气体通道侧壁的非原位装置，研究了气体通道内的两相流动。在通道入口歧管处供应空气，并且沿着通道的长度沿着通过GDL连续且均匀地供应水。这不同于以往两相流研究者所研究的在通道入口处同时引入空气和水。GDL在气体通道和水室之间被压缩以模拟PEMFC条件。空气和水的表观速度分别为0.25 ~ 34.5 m/s和1.54 × 10− 5 ~ 1.54 × 10− 4 m/s。用两个GDL在垂直和水平方向上运行非原位设置，-基线（Mitsubishi Rayon Co. MRC 105，具有5重量% PTFE并涂覆有通用汽车公司的内部MPL）和SGL 25 BC -以及三通道处理-疏水、亲水和未处理的Lexan，接触角分别为116°、11°和86°。由于取向、GDL类型或通道涂层，没有注意到明显的影响。在沿着通道的不同位置处观察流态，并将其表示为表观空气速度和水速度的函数。流态标准的开发和验证对非原位数据观测的范围。提出了一种新的变水流量压降模型，以考虑进入通道的水在沿流长沿着多个位置处的变化。压降模型开发的特定的流态和实验数据验证。该模型能够预测的实验压降数据的平均误差小于14%。
The two-phase flow in the gas channels of a proton exchange membrane fuel cell (PEMFC) is studied with an ex situ setup using a gas diffusion layer (GDL) as the sidewall of the channels. Air is supplied at the channel inlet manifold and water is supplied continuously and uniformly through the GDL along the length of the channel. This is different from the simultaneous air and water introduction at the inlet of the channel as studied by previous two-phase flow researchers. The GDL is compressed between the gas channels and the water chambers to simulate PEMFC conditions. The superficial velocity for air and water ranged from 0.25 to 34.5 m/s and 1.54 × 10−5to 1.54 × 10−4m/s, respectively. The ex situ setup was run in both vertical and horizontal orientations with two GDLs, – Baseline (Mitsubishi Rayon Co. MRC 105 with 5 wt.% PTFE and coated with an in-house MPL by General Motors) and SGL 25 BC – and three channel treatments – hydrophobic, hydrophilic, and untreated Lexan, with contact angles of 116°, 11° and 86°, respectively. No appreciable effect was noted because of the orientation, GDL type or channel coatings. The flow regime is observed at different locations along the channel and is expressed as a function of the superficial air and water velocities. Flow regime criteria are developed and validated against the range of ex situ data observations. A new variable water flow rate pressure drop model is developed in order to account for the variation of water entering the channel at multiple locations along the flow length. Pressure drop models are developed for specific flow regimes and validated against experimental data. The models are able to predict the experimental pressure drop data with a mean error of less than 14%.