Design and Construction of Long Cryogenic Piping Lines

Abstract

It is generally complicate and delicate to determine a heat leak of a cryogenic piping line such as liquid helium transfer line and a cold helium transfer line. The heat leak is ordinary evaluated to measure liquid helium transfer coefficient, or mass flow rate and enthalpy difference through the piping line. However, it is almost impossible to determine the heat leak in the case that there aren't any sensors to measure the inlet and the outlet condition of transferring helium. This chapter helps in developing a unique heat-leak measurement method useful to determine the heat leak for a long-length cryogenic piping line. The method is only to measure the outer surface temperature of the cryogenic piping line when liquid helium flowing. The method has been verified that the measurement result by the method has a good agreement with the other measurement method such as a liquid helium transfer efficiency measuring method and a enthalpy mass flow rate measurement method. The method provides a simple verification method for cryogenic piping line performance.