전기화학 수소 압축기 성능 및 기계적 특성에 대한 셀 디자인 변수의 영향 조사

초록

An electrochemical hydrogen compressor (EHC) is considered as promising technology for hydrogen compression. In this study, the influence of cell design variables on performance and mechanical behavior was numerically investigated for efficient and reliable operations of EHC. The distributions of stress and water concentration were examined by coupling computational fluid dynamics (CFD) and finite element method (FEM) methodology. First, the EHC model is validated against the experimental data with different Nafion membranes of N115, N117, and NR212. In general, the gas diffusion layer (GDL) intrusion toward the low-pressure side (anode) is observed induced by cell assembly and pressure gradient between the anode and cathode. While the stress level tends to be decreased with increase of the membrane, GDL thickness. Regarding the cell performance, the dehydration which i s critical i ssue for EHC operation, i s mainly a ffected by ohmic potential due to the proton transport through the membrane. In previous studies, specific causes of the anode dehydration issue and structural problems in the cell due to pressure differences in the electrochemical hydrogen compressor (EHC) were not well elucidated. Through this research, using the computational science approach, we have identified and analyzed these underlying causes and conducted simulations to assess the performance and structural stability of the cell based on various cell design factors required for design optimization and solution. Particularly, the simulations also show that when common GDL materials such as carbon paper, carbon cloth, and carbon felt are employed, breaking of GDL could not be avoided with high hydrogen compression ratio (e.g., 100), which clearly indicates that the structure strength and resistance of GDL should be improved.

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