Experimental study on heat transfer performance of fin-tube cross-flow gravity heat pipe backplanes

In this paper, the working principle of the gravity heat pipe backplane system is presented, and the differences in heat transfer performance of the fin-tube cross-flow gravity heat pipe backplane with different pipe diameters are experimentally studied. The results show that under the comparative test conditions in this paper, the heat transfer performance of the improved 7 small tube-diameter heat exchanger can meet the heat transfer requirements of the existing 9.52 tube-diameter heat exchanger, and the material cost can be saved by 12.9%. In practical application, it is recommended that the temperature of the liquid supply subcooling and the gas outlet superheat of the backplane should be controlled between 0.5 ℃ and 1.5 ℃, and the temperature difference between liquid supply and gas outlet should be controlled between 1 ℃ and 2 ℃. When the heat transfer capacity of the gravity heat pipe backplane system does not reach the heat transfer limit, the heat transfer rate can be effectively improved by reducing the water supply temperature of the condensing unit and increasing the return air temperature of the backplane.