Co-design and aerodynamic study on a two-step high pressure reducing system for hydrogen decompression: From hydrogen refueling station to hydrogen fuel cell vehicle

Abstract

Fuel for hydrogen fuel cell vehicles comes from hydrogen refueling stations. During the hydrogen filling process, a high-pressure gradient from 35 MPa (hydrogen storage pressure) to 0.16 MPa (fuel cell pressure) is generated. Such a large pressure gradient posed a challenge to the design of the pressure reducing system. Traditional system is difficult to reduce hydrogen pressure from 35 MPa to 0.16 MPa without accompanying large noise and energy consumption. This work is exploring a new concept to combine the multi-stage continuous resistance perforated components and the Tesla valve to design a two-step high pressure reducing system for hydrogen decompression. To validate the superiority of the developed system, a detailed aerodynamic study on the new system is performed, since aerodynamic performance directly affects the operating flexibility and stability. Finally, the optimized co-design of the system is achieved. Results show that the new system is well-designed for hydrogen decompression with the function of control noise and energy consumption. Larger orifice radius (r1/r0) and orifice ratio (k) contribute the better aerodynamic performance. Angle α = 45° is considered the best for better aerodynamic performance. The descending order of the effects on better aerodynamic performance is angle (α), row (m), sleeve stage (N), orifice radius (r1/r0) and width (t1/t0). This study provides basic support for experts to achieve throttling design of related pressure control systems in hydrogen industry.