Dynamic Characteristics of Flow Limiting Valve for Hydrogen Fuel Cell Vehicles

In the hydrogen supply system of hydrogen fuel cell vehicles, flow limiting valves play a crucial role in preventing significant hydrogen leakage in the event of accidents, greatly enhancing safety. This study established a mathematical model that considers changes in port opening, to analyze the dynamic characteristics of the flow limiting valve. A slope signal is used to simulate pressure changes in the valve when pipe ruptures occur, and the initial pressure value is obtained from Computational Fluid Dynamics (CFD) simulation results. It is found that the structural parameters are closely related to its design indexes. Specifically, when the downstream pressure remains the same, an increase in the cone angle of the spool, valve body diameter, and damping orifice diameter enhances the valve's flow capacity, leading to a larger closure flow rate, but results in a decreased response speed. Changes in the conical valve structure have a more pronounced impact on the operational characteristics of the flow limiting valve.