Transient boiling in two-phase helium natural circulation loops

摘要: Two-phase helium natural circulation loops are used for cooling large superconducting magnets, as CMS LHC. During normal operation or in the case of incidents, transients exerted on system. Here a system this type is studied experimentally. Sudden power changes operated vertical-heated-section convection loop, simulating fast increase heat deposition magnet pipes. Mass flow rate, heated section wall temperature and pressure drop variations measured function time, to assess time behavior concerning boiling regime according values injected section. The curves critical flux (CHF) have been obtained steady state. Temperature evolution has observed order explore operating ranges where transfer deteriorated. Premature film during some ranges, even at appreciably lower than the...