Numerical investigation on the dispersion characteristics of cryogenic helium vapor cloud in confined space

Abstract Helium cryogenic systems have been widely used in large-scale scientific engineering fields utilizing superconducting technology. Once suffering from vacuum insulation failure, magnet quenching, material defect, mechanical fatigue, external impact, electrical joint failure, etc., the protective devices and key components of helium cryogenic system could rupture and fail. The cryogenic helium will then leak into surrounding environment, posing severe threat to the safety of personnel, equipment, and building. Previous studies mainly evaluated the potential hazards of extremely low temperature, hypoxia, and overpressure induced by the accidental leakage of cryogenic helium into confined space from macroscopic perspective, while rarely focused on the dispersion characteristics of cryogenic helium vapor cloud. In the present work, CFD model predicting the leakage and dispersion of liquid helium in confined space is developed firstly. Then, the dispersion characteristics of cryogenic helium vapor cloud in confined space, including evolution stage, concentration distribution, relation between cloud temperature and concentration, etc., are numerically investigated from microscopic perspective. The work provides guidance for the prediction and safe protection of the leakage and dispersion of cryogenic helium in confined space, which helps to improve the safety of helium cryogenic system further.