Abstract:

Electrolysis for hydrogen production is a key driver for the future of green energy. The filter-press water electrolyzer is a widely-used industrial hydrogen production device, where the uniform distribution of electrolytes is crucial for extending electrode lifespan and enhancing electrolysis efficiency. However, the flow field distribution uniformity in traditional mastoid plates is poor, resulting in low electrolysis efficiency and even local overtemperature, which leads to safety problems such as electrode ablation. To overcome this problem and enhance the flow distribution within the electrode plates, a “dense in center, sparse in sides” convex-concave unit distribution strategy for mastoid plates is proposed. First, a visual experimental platform for the mastoid plates was constructed to study the distribution of alkaline solution residence time and validate the simulations. Subsequently, the single-phase flow characteristics of four different dimpled plate structures were simulated, and the flow dead zones were quantitatively characterized using a coupled particle tracking algorithm. The results show that the new convex-concave unit distribution strategy can make the electrolyte flow field inside the electrolytic cell more uniform, minimizing electrolyte backflow and reducing the formation of dead zones. Furthermore, this strategy enhances system flexibility to accommodate a broader range of flow conditions.

Key words: water electrolysis, filter-press water electrolyzer, convex-concave structure, flow uniformity, structural optimization, flow dead zone, residence time distribution

摘要：

电解水制氢是引领未来绿色能源发展的重要途径。压滤式水电解槽是常用的工业制氢装置，其中电解液分布的均匀性对提高电解效率和延长电极寿命至关重要。然而，传统的乳突板内流场分布均匀性差，导致电解效率变低，甚至出现局部温度过高，从而引发电极烧蚀等安全问题。为改善这一现象，提出“中心密，两侧疏”的凹凸单元分布策略，以改善极板内部的碱液流场分布。首先，搭建乳突板可视化实验平台，研究碱液停留时间分布，并用于数学模型验证。进而模拟了四组不同结构乳突板的单相流特性，并耦合颗粒追踪算法定量表征流动死区。结果表明，新的凹凸单元分布策略能使电解液在电解槽内的流场更加均匀，减少碱液的返混现象，降低流动死区的产生。此外，该方法还提高了系统的操作弹性，使其能够适应更广泛的流量条件。

关键词: 电解水制氢, 压滤式电解槽, 凹凸结构, 流动均匀性, 结构改进, 流动死区, 停留时间分布