Abstract
As part of the energy transition from a fossil-based system to a system based on climate-friendly energy sources, a new energy carrier for mobile applications is needed, replacing conventional fossil-based fuels. With its high energy density, compressed hydrogen is a promising candidate for such an energy carrier. In recent times, there has been an increased industry and research interest in hydrogen technology.
Due to the inherent difficulty as well as dangers of working with inflammable and low-viscosity hydrogen, there is a need for the development of specialized components for the transport and storage of pressurized hydrogen. Due to hydrogen-specific damage on polymeric seals, metallic sealing is the preferable method to hinder the flow of hydrogen through closed valves or unwanted leakage between connecting components such as screw fittings. Until the writing of this paper, the sealing mechanism of seals formed by metals for gases has not been well understood. Existing theories describing liquid leakage through metallic seals cannot be applied without modification to describe gaseous systems.
This article was written to describe how gas leakage can be modeled. In it, a procedure based on the contact mechanics model developed by Persson is presented. It discusses possible solutions to modify the existing flow models utilizing this theory and presents possible adaptations of this theory to sealing relevant to the hydrogen industry.
To support the presented methods, the flow models developed for this paper were compared to measurements on a sample system. The leakage was described using a valve consisting of a steel ball lying on a steel seat, sealing off pressurized air. This experimental validation highlights the successes and shortcomings of the used methods and can be used for the development of a refined model in future works.
