A major component of a high-T C superconductor current lead designed to provide current to Iow-T C superconductor magnets is the heat intercept connection, which is a cylindrical structure consisting of an inner Cu disk, a thin-walled G-10CR composite tube, and an outer Cu ring, assembled by a thermal-interference fit. It was determined in a previous study that the thermal contact resistance (R C) between the composite tube and the two Cu pieces contributed a substantial portion of the total thermal resistance between the inner and outer Cu pieces. The present report emphasizes the analysis of the data for the third and final design of the heat intercept connection. In particular, it is found that R C decreases dramatically with increasing heat flux, a result consistent with earlier studies of composite cylinders. However, for the present data, the thermal contact conductance (= 1/R C) varies with the calculated contact pressure with a power-law exponent of approximately 10, as compared to a theoretical value near 1. In addition, the presence of He or N 2 gas substantially reduces R C, even though the contacting surfaces are coated with a thermal grease.
|Original language||English (US)|
|Title of host publication||American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD|
|Number of pages||7|
|State||Published - 1996|
ASJC Scopus subject areas
- Fluid Flow and Transfer Processes
- Mechanical Engineering