Multiphysics Performance Analysis And Design Optimization Of Solid Oxide Fuel Cell/Electrolysis Cell Stack

Solid Oxide Fuel Cell(SOFC)and Solid Oxide Electrolysis Cell(SOEC)have great application prospects in clean energy development,the former as an efficient energy conversion device with high efficiency,low pollution and no noise,and has great application prospects in clean energy use;the latter as an energy conversion and storage technology with high theoretical efficiency by converting electrical and thermal energy into chemical energy stored in the product through electrolysis.SOFC and SOEC(SOC)reactors have the same structure and material system,and the electrode reactions are inverse to each other,so the development research between them can learn from each other.Due to the different electrochemical reactions of the two electrodes,there are obvious differences in structural design,performance changes and property distributions,so they need to be studied separately.Due to the complexity of SOC multiphysics field calculations,most of the current research has focused on single-cell and small-scale stack models.In order to study the performance variation of large-size stack and to optimize the design of the stack structure,this paper successfully constructs a numerical multiphysics model for large-size SOC stack using alternative mapping methods,the performance distribution of 50-layer SOFC stack with different anode channel height and co/counter-flow arrangements were studied,and the optimized design of the gas distribution structure of 150-layer stack towers was reserached and analyzed.In addition,this paper investigates the performance variation of the 50-layer SOEC stack under different operating conditions and different structures,which provides reference experience for the experimental operation and structure optimization of the SOEC stack.The study shows that for a 50-layer SOC stack,the improvement of flow uniformity has limited improvement on the stack performance,but the low gas flow channel will cause the stack resistance to rise sharply,and the stack resistance will exceed 3 KPa when the channel height drops to 0.2 mm;in addition,the SOFC stack output performance improvement is very small when the counter-flow,while the temperature gradient increases by 80%.For the 150-layer SOFC stack tower structure,the flow uniformity has a great influence on the internal temperature distribution,and when the channel height is 0.3mm and the stack Manifold cross-section length is increased by 16mm,the stack flow uniformity is improved by 33%and the maximum temperature difference is decreased by 20%.When SOEC is operating,excess air has very little effect on temperature distribution improvement,and increasing the inlet H2O-H2 ratio can reduce power loss.