Test stand for determination of the heat flux to the cold elements of cryogenic systems in case of the vacuum vessel failure

摘要

The design process of cryogenic equipment requires sizing of the safety accessories for all enclosures containing cryogenic gas or liquid. The size of the accessories depends on the heat load to the cryogen. Vacuum failure following the ventilation of the insulating vacuum with atmospheric air is often considered as a maximum credible incident. For such case the heat inputs to blank liquid nitrogen and to liquid helium vessels have been experimentally determined by other researchers. Nevertheless, for helium systems elements as an actively cooled thermal shield, with a MLI covered external side and bare internal side, experimental data does not exist. WUST has designed a test stand that allows the experimental determination of the heat flux to the helium vessel, nitrogen vessel and to the thermal shield in case of the accidental break of the vacuum. The paper describes the test stand design and test methodology.