Performance Calculation Analysis And Structural Optimization Design Of Adjustable Fuel Cell Ejector

In recent years,with the continuous consumption of traditional energy sources and the increasingly serious pollution problems,the world has begun to explore and research clean energy.The diverse sources of hydrogen,clean,low-carbon,and wide range of application scenarios make it an effective alternative to traditional energy sources.Proton Exchange Membrane Fuel Cell(PEMFC),which uses hydrogen as an energy source,has received a lot of research,and how to give full play to the efficiency of hydrogen in PEMFC has also become a research focus.In this paper,a flow-adjustable ejector is proposed to realize hydrogen recirculation.Combined with numerical simulation methods and experimental tests,the influence of different structural parameters and operating conditions on the ejector is analyzed.Firstly,This paper introduces the structure and modeling process of the adjustable ejector in detail.Based on the theoretical equation of the ejector,three-dimensional computational fluid dynamics(CFD)simulation software is used to model and model the adjustable ejector.The calculation conditions are set;the adjustable ejector is made by 3D printing technology,the test bench of the ejector is built,and the validity of the adjustable ejector model is verified through experimental data.Secondly,determine the key structural parameters that affect the performance of the adjustable ejector,including the diameter of the equal volume mixing chamber dt,the length of the equal volume mixing chamber It,the nozzle and the entrance distance of the equal volume mixing chamber lnxp,and the equal pressure mixing chamber length li,the angle of the equal pressure mixing chamber αi,the angle of the diffusion chamber ad,the diameter of the diffusion chamber ld etc.,the mass flow rate of the secondary fluid and the ejection coefficient are used as indicators to evaluate the ejector performance,and the influence law of different structural parameters is analyzed.The key structural parameters are optimized according to a certain optimization sequence,and the final optimization plan is determined.Finally,based on the optimization scheme of the adjustable ejector model,the simulation analysis of different operating conditions is carried out,and the operation conditions such as primary fluid mass flow,primary fluid temperature,secondary fluid humidity,secondary fluid temperature and secondary fluid pressure are studied for ejection.The influence law of the performance of the ejector;based on the experimental bench built to compare the performance of the front and rear ejectors,the results show that compared with the fixed ejector,the optimized adjustable ejector has better ejection performance.The research results can provide theoretical guidance for the design and application of adjustable ejectors.