Study On Flow Field And Strength Performance Of Pressure Regulator Of Hydrogen Fuel Cell Vehicle

With the increasingly severe environmental problems,countries around the world pay special attention to the production and utilization of new energy,and various industries are vigorously promoting the low-carbon transformation of equipment.For the automotive industry,hydrogen fuel cell vehicles have been focused on because of their advantages of zero pollution,high efficiency,short time for refilling hydrogen and long endurance mileage.High-pressure hydrogen regulator is key part in hydrogen supply system of hydrogen fuel cell vehicle.At present,the hydrogen bottle produced and commercialized in our country is 35 MPa.In order to improve the endurance mileage of hydrogen fuel cell vehicles,it is necessary to increase the hydrogen storage pressure to 70 MPa,and the operating pressure of regulator increases correspondingly.Long-term operation in high-pressure hydrogen environment easily leads to the deterioration of mechanical properties of materials,which poses a threat to the safety of regulator.In order to study the decompression performance,improve the stress distribution of structure and ensure the safe and reliable operation of hydrogen regulator,this paper studies the high-pressure hydrogen regulator based on the fluid-structure interaction analysis method.The varying law of various physical parameters of the internal flow field,the decompression performance and the influence of the flow field parameters on the regulator structure are explored.Accordingly,the structure is optimized to improve the stress distribution.The specific research contents are as follows:(1)A numerical model of global three-dimensional of high-pressure hydrogen regulator is established,and a pressure adjustment method suitable for high-pressure inlet boundary is proposed,which improves the convergence of numerical simulation and the accuracy of results.The numerical simulation of steady-state compressible flow is carried out with Fluent software,and the varying law of the physical parameters of flow field such as pressure,velocity and temperature under different valve opening,inlet and outlet pressure is studied.(2)The tensile test of the metal materials used in the main parts of high-pressure hydrogen regulator is carried out,and finally the mechanical properties such as elastic modulus,yield strength,tensile strength,elongation at break and area shrinkage are obtained.The stress-strain data are collected to provide more accurate material parameters for the design and analysis of the structure of regulator.(3)The unidirectional fluid-structure interaction model of high-pressure hydrogen regulator is constructed,the physical parameters of flow field are coupled to the structure,and the data of fluid-structure interface is applied to structure as a load to solve the stress and deformation.The stress distribution under different valve opening and inlet pressure is obtained,so as to determine the minimum working pressure leading to the yield failure and the weak links of the structure,and the corresponding structural optimization is carried out.In this paper,the fluid-structure interaction research of pressure regulator in 70 MPa high-pressure hydrogen environment is carried out,and the fluid and structure domain of regulator are comprehensively studied,which provides data support for the research and design of regulator used in hydrogen environment.