微重力水电解槽两相热流动与水量分配数值模拟

建立了固体聚合物电解槽单体的三维两相流动模型和电解槽系统供水过程模型,对电解槽的供水、两相流动和温度场特性进行模拟仿真,分析放置方式和微重力环境等因素对其工作性能的影响.电解槽单体的数值模拟结果表明,在微重力条件下或者水平放置时,其内部速度场和温度场都分布均匀.但是采用竖直放置且水平供水方式时,电解生成的氧气在电解槽上部聚集,出现局部缺水现象.对电解槽系统供水过程的数值模拟结果表明,无论在地面还是微重力条件下,电解槽系统的水量分配都是不均匀的.水平放置时,电解槽系统内的电解槽单体进出口水量从底部至顶部先减少后增加;在竖直放置或微重力条件下,水量从其底部至顶部持续增加.

Numerical Simulation of Two-phase Heat Flow and Water Distribution for Water Electrolyzer in Microgravity

Water electrolysis technology is a green-hydrogen process, and it is also a critical oxygen filling technology for medium- and long-term manned space missions. To study the effect of gravity on the performance of solid polymer water electrolyzer, the 3D two-phase model and the system model of electrolyzer were established. The water distribution, flow and temperature field were simulated and the effects of microgravity and normal-gravity on the electrolyzer were analyzed. When the electrolyzer placed in microgravity or horizontally, the numerical simulation of the electrolyzer with single-cell showed that the flow and the temperature fields in the electrolyzer are distributed uniformly. However, when the electrolyzer was placed vertically and water supplied horizontally, the water shortage appeared in the electrolyzer due to the oxygen gathered in the upper part. The numerical simulation of the system model indicated that the water distribution of the system is nonuniform in both normal-gravity and microgravity conditions. When the electrolyzer system was placed horizontally, the system flow rates firstly decrease then increase from the bottom cell to the top cell. While when the electrolyzer system was placed in microgravity or vertically, the system flow rates always increase from the bottom cell to the top cell.