Experimental and simulation research on hydrogen leakage of double ferrule joints

Abstract

Owing to the scope of large-scale use of hydrogen energy in future technology, addressing safety issues like leakage and diffusion in all steps of production, storage, transportation, etc., will become inevitable. This paper focuses on the volume change of the combustible area after double ferrule joint leaks. First, a calibrated computational fluid dynamics (CFD) model was built and calibrated for accuracy through a hydrogen horizontal jet process. Second, the schlieren method was used to observe the hydrogen leakage morphology when the pipe was scratched. The CFD model was used to investigate the morphology and combustible volume changes under different wind directions and speeds. Third, critical wind speed (CWS), representing the disturbance wind speed when the combustible volume generated by the hydrogen jet was reduced to 85% of the non-disturbed environment, was proposed. Fourth, the scratch leakage behavior with the double ferrule joint placed horizontally was simulated. This research found that forced convection in the hydrogen system reduced the combustible volume produced by the hydrogen jet, and the typical value of CWS here was 1.5 m/s.