Forced convection heat transfer to supercritical fluids

Shiotsu, Masahiro*; Tatsumoto, Hideki; Shirai, Yasuyuki*

In designing a superconducting coil wound with Cable in Conduit Conductor cooled by supercritical helium, accurate knowledge of heat transfer in forced flow of He I under supercritical pressure is necessary. The authors performed experiments on heat transfer from a test plate in a horizontal duct cooled by supercritical helium. On the other hand, there have been many experimental data and correlations for non-cryogenic fluids such as water and CO at supercritical pressures. Most of these data are on far longer tubes compared with our data for helium, and ratios of wall temperature increase to the critical temperature are far lower than that for helium. In this work, our data for supercritical helium above mentioned are compared with the correlations for the non-cryogenic fluids. The data are not predicted well by the correlations. The reasons of the discrepancies are considered and a new generalized correlation is presented.