One of the worst accidents that may occur in a high-vacuum-multilayer-insulation (HVMLI) cryogenic tank is a sudden, catastrophic loss of insulation vacuum (SCLIV). it is obvious that the different gas leaking into the insulation jacket have some influence on the heat transfer process. However, this problem has not been studied systematically so far. In this paper, a test rig was built up and experiments were conducted on a SCLIV cryogenic tank by using the nitrogen, helium, oxygen, carbon dioxide and air as the leaking medium, respectively. Some important phenomena and heat transfer characteristics in a vacuum-lost HVMLI cryogenic tank have been obtained. The effects of the insulation layer numbers and the type of gases on venting rate and heat flux into the cryogenic liquid have been measured, analyzed and discussed. It indicates that the heat transfer performance of the HVMLI cryogenic tank after SCLIV is strong related to the type of gases leaking into the insulation jacket.
