Modeling and analysis of minor seal leakages in high-pressure hydrogen valves under extreme environmental temperatures

The damage to the sealing rings of high-pressure hydrogen valves caused by extreme environmental temperatures, leading to minor hydrogen leakage, is a significant issue in the field of hydrogen safety. However, current understanding is still limited regarding the initial leakage of hydrogen through damaged gaps in sealing rings. This paper aims to explore the distribution of hydrogen leakage in sealing rings with various-shaped damage gaps under extreme environmental temperatures. Firstly, the real damage gaps of the sealing rings are obtained on an extreme temperature experimental platform. Then, a coupled hydrogen leakage model is established, which calculates the viscosity of hydrogen in real-time as temperature changes. Based on these models, the concentration, temperature, and velocity distribution of hydrogen within the sealing ring gaps under extreme environmental temperatures are studied. The results indicate that the high-pressure hydrogen within the gaps, influenced by viscosity and wall adhesion effects, tends to diffuse along the wall surfaces. The high-temperature zone along the edge lines of the gaps lasts longer than that on the centerline. Under extreme high temperature conditions, the average velocity at the inlet and outlet of the gap is 21.6% higher than under extreme low temperatures.