Analysis of the Effect of Different Internal Flow Path Geometries of a Triple Seal Check Valve for Hydrogen Refueling on Compressible Turbulent Flow Characteristics and Exergy Losses

In this study, RANS-based numerical analyses were performed for four flow paths located at the top of the operating section with groove (R) and diameter (D) geometry modifications to analyze the compressible turbulent flow characteristics and the effect on the check valve efficiency for hydrogen refueling. The results showed that the turbulent kinetic energy and turbulent dissipation rate increased in the flow path and the section leading to the outlet section under all geometry modification conditions, and the flow was biased toward the outlet section as the size of D increased with respect to the base condition. In addition, as the size of D decreased in the presence or absence of R, the flow path velocity in the outlet section decreased due to the bottleneck, and the turbulent kinetic energy and turbulent dissipation rate decreased accordingly. The generated entropy inside the flow path tends to decrease as the diameter increases with D = 2.5 mm, and the exergy analysis shows that (R = 0.5 mm, D = 3.5 mm) = (−) 10.26% and (R = 0.5 mm, D = 3.0 mm) = (−) 7.44% compared to the base condition.