Experimental studies on the heat transfer characteristics of helium-based cryogenic oscillating heat pipes

Purpose Copper is a cooling transfer material used in cryogenic superconducting systems. The effective thermal conductivity (ETC) of copper in the 4K region is only about 400 W/(m K). Its heat transfer performance is poor, there are some shortcomings such as large temperature difference, temperature fluctuation lag, cryogenic system layout limited. The ETC value of helium-based cryogenic oscillating heat pipes (COHP) in the 4K region is much higher than that of copper. However, the choice of heating power interval is very important, and the heating power will affect the oscillation characteristics of COHP.
Methods In this study, a helium-based COHP heat transfer performance test platform was built in the 4K region, and the effects of heating power and liquid filling rate on oscillation conditions and ETC were studied. The heating power ranges from 0.1 to 0.5 W, and the liquid filling rate ranges from 20% to 87%.
Results and conclusion The heating power interval suitable for oscillation behavior is given quantitatively. The intrinsic correlation between ETC and amplitude is further discussed. The results are of great significance for improving the performance of cryogenic superconducting systems.