Experimental investigation on the effects of water flow rates and wind speeds on the temperature and performance of PEM electrolyzer stacks

The performance degradation of the proton exchange membrane (PEM) electrolyzer stack can possibly be induced by the regulation of water flow rates and the loading of the wind environment. The effects of water flow rates and wind speeds on the performance evolution of the PEM electrolyzer stack were experimentally investigated using the constant current method. The runaway mechanism of electrolyzer stacks in the case of water starvation was explored. Moreover, optimization strategies for the wind environment and water starvation were proposed. The results indicate that the dual function of heating and cooling can be found by varying the water flow rate. When water flow is utilized for heat supply to the stack, the electrical performance is enhanced. In a wind environment, the heat dissipation of electrolyzer stacks can be improved by increasing the inlet water temperature, current density, or wind speed. At a wind speed of 10.1 m/s, the maximum rate of performance degradation reaches 5.11 %. It is found that increasing the water flow rate can improve the voltage uniformity of the stack in the wind environment. Furthermore, the voltage runaway is induced by the water starvation, resulting in a single electrolysis cell voltage reaching 18.06 V. The implementation of a voltage limit is an effective strategy for mitigating the severity of voltage runaway. The findings contribute to understanding the effect of water flow rate on thermal management and providing data support for the application of stacks in the wind environment.