Finite Element Simulation Research On Structural Strength Of Lightweight High Pressure Hydrogen Solenoid Combined Valve For Vehicles

As a low-carbon,clean and environmentally friendly energy source,hydrogen energy is included in the "14th Five-Year Plan" and its 2035 long-term goals,promoting the development of China's hydrogen energy industry and realizing the vision of "carbon peak" and "carbon neutrality".High-pressure gaseous hydrogen storage is relatively low in cost and convenient to store and release hydrogen.It is the preferred method of hydrogen storage in the world,but its safety factor is low,which is an urgent problem to be solved.As an important component in the hydrogen transmission and storage system,the high pressure hydrogen solenoid valve for vehicle is still in its infancy in China,and there is a lack of in-depth research on the design methods of structural strength and reliability in the high pressure hydrogen environment.In order to reduce weight,6061-T6 aluminum alloy is mainly used as valve body material in the world.C ompared with high-strength stainless steel,6061-T6 aluminum alloy has limited strength.It is necessary to use autofrettage to improve structural strength under high pres sure.There is no research on the optimal autofrettage pressure of the high-pressure hydrogen cylinder valve and the structural strength of the high-pressure hydrogen cylinder valve of a car on the road under external excitation load.In response to the survey,in order to ensure the structural strength and reliability of the high-pressure hydrogen solenoid valve,the following studies were carried out:(1)Researched the materials suitable for high-pressure hydrogen solenoid combination valves at home and abroad,and concluded that 6061-T6 aluminum alloy is an ideal material for light-weight automotive high-pressure hydrogen valves.The structural strength of the valve body under the maximum working pressure is analyzed by the finite element method,A theoretical study on the threaded part of the connecting pipe where the structural strength of the hydrogen valve is weak is carried out,and the finite element analysis is used to analyze the structural strength of the main and auxiliary valve bodies under different material combinations The load-bearing law of the roots of the threaded joints of the valve body is studied,and the analytical solution is verified by comparison.(2)Aiming at the necessity of autofrettage treatment for 6061-T6 aluminum alloy high-pressure combination valve,the theoretical calculation of the maximum autofrettage pressure of the simplified high-pressure hydrogen solenoid valve body is carried out.Sample points are obtained through experimental design,and the maximum stress value corresponding to the sample point is obtained by Isight software integrated with ANSYS Workbench finite element analysis software.An approximate model corresponding to the design variable autofrettage pressure and the maximum stress value of the target value is established,and the multi-island genetic optimization algorithm is used to determine the optimal autofrettage pressure of the valve body.The finite element comparative analysis of the structural strength of the self-reinforced and untreated valve body and pipe thread is carried out,and the improvement of the structural strength after the autofrettage treatment is summarized.(3)In view of the structural strength of the high-pressure hydrogen combination valve of a car on the road under external excitation load,The finite element method is used to study the structural strength of the valve body of the high-pressure hydrogen solenoid valve body subjected to inertial impact loads on bumpy roads and shar p turns;The fatigue strength of the valve body structure of the high-pressure hydrogen solenoid valve under the random vibration load of the road surface is studied.The results show that the stress of the valve body under inertial impact load during road driving meets the structural strength requirements,and the fatigue strength of the valve body meets the design requirements under the random vibration excitation load on the road surface,and the strength and reliability of the high-pressure hydrogen combined valve can be ensured when it is subjected to an external excitation load during road driving.