Performance analysis of PEMEC with non-uniform deformation based on a comprehensive numerical framework coupling image recognition and CFD

Abstract

Proton exchange membrane electrolysis cell (PEMEC) is widely regarded as an efficient device for producing green hydrogen. Proper clamping pressure during cell assembly can reduce contact resistance while ensuring sealing and safety. Meanwhile, the clamping pressure will cause deformation of the cell components, resulting in increasing mass transfer resistance. However, the evolution law of multi-physical parameters under different clamping pressures has not been fully studied. In this study, a comprehensive numerical framework is proposed for non-uniform deformation and performance analysis of PEMEC. The framework includes three parts: non-uniform deformation model, data transmission based on image recognition, and three-dimensional (3D) multi-phase and multi-physical model. The effects of cell component non-uniform deformation on heat and mass transfer, and electrochemical characteristics are studied. The purity of hydrogen production is also fully taken into consideration. Results show that high clamping pressure causes severe deformation of liquid and gas diffusion layers under the land and a significant decrease in porosity and permeability. In addition, the accumulation of oxygen in the flow channel will weaken the liquid water supply rate and form a high oxygen covered region on the membrane. The current density inhomogeneity in this region will increase significantly with clamping pressure. Although high clamping pressure can obtain low contact resistance and high output hydrogen molar fraction, it also increases mass transfer resistance. An appropriate clamping pressure of 3 MPa is recommended with a lower cell voltage of 2.12 V at 2A/cm2 after considering the physical and chemical properties. The present study can provide helpful guidelines on the design of large-scale electrolyzers.