Speaker
Description
Liquid helium is widely used as a cooling agent for superconducting magnets. In case of an incident such as a magnet quench, the pressure in liquid helium cryostats increases rapidly. Hence, the cryostat has to be protected against overpressure by relieving the helium through a safety device, e.g. a safety valve. The discharge mass flow rate is limited by the so-called chocked flow in the narrowest cross-section, where the flow velocity reaches the fluid’s speed of sound.
Due to its fluid properties, helium typically expands into the two-phase region in the safety valve, where the speed of sound is undefined. Idealized models for sound propagation in two-phase flow are found in the literature, but not experimentally validated for helium.
This talk gives an overview of existing models for the calculation of discharge coefficients in case of two-phase flow. Finally, the talk outlines planned activities to validate a method for helium in spring-loaded safety valves.
