Temperature distribution evolution in zero-gap alkaline water electrolyzer: Experimental and modeling

Alkaline water electrolysis technology is currently the most prospective commercial choice for producing green hydrogen, however, accurately modeling the temperature distribution evolution inside the alkaline water electrolyzer is still a challenge, since the existence of strong coupling multi-physical fields among gas–liquid flow, electrochemistry and heat transfer. In this article, 3D simulation models of the zero-gap alkaline water electrolyzer are established considering the mutual coupling relationship among two-phase flow, electrochemistry and heat transfer as well as the bypass current effect to study the heat transfer property and temperature profiles under different electrolysis conditions. The simulation study is conducted for the electrolyzer consisting of five electrolysis cells. The voltage, temperature difference and gas production rate were measured experimentally and simulated well using the established models. It indicates that the average relative error is respectively 0.45% for the estimated cell voltage, 13% for the estimated outlet-inlet temperature difference of the cathode flow channel, and 1.18% for the estimated hydrogen production rate. The characteristics of temperature distribution evolution in the zero-gap alkaline water electrolyzer have been disclosed, accordingly the suitable heat management strategy has been suggested for the stable operation. The results would provide a useful guide on the optimization and design of large-scale alkaline water electrolyzer to implement long-term stable operation with low cost.