Research on dynamic characteristics of a high-pressure and high-precision hydrogen pressure reducing valve for small mobile vehicles

High-pressure hydrogen pressure reducing valve (HPRV), as a key component of hydrogen fuel cell vehicles (HFCVs), directly affects the performance of the entire vehicle system. In this paper, a two-stage high-pressure and high-precision reducing valve for small mo bile vehicles is designed, and an equivalent fitting method for the stiffnesses of metal diaphragms is proposed. Finite element simulation analysis reveals that scale factors can be used to characterize the effects of changes in material and structural parameters of the metal diaphragms on their equivalent stiffnesses. The mathematical model of the HPRV was established. Through simulation analysis, it is concluded that the equivalent stiffness of the secondary diaphragm, the half-cone angle of the secondary spool, and the volume of the secondary feedback chamber significantly affect the dynamic characteristics of the HPRV. Based on the simulation results, the structural parameters of the valve were opti mized, and the developed prototype was experimentally studied. The experimental results show that the HPRV has good dynamic characteristics and meets the design requirements. The research in this paper can lay a foundation for the development of high-precision HPRVs with small flow rates.