Technology Development And Enhanced Heat Transfer Effect Evaluation Of Surface Modification In Gravity Heat Pipe

Along with energy shortage extended day by day and the development trend of energy efficient utilization, the study on enhanced heat transfer of heat pipe has attracted increasingly significant attention. So this paper relied on ordinary gravity heat pipe, mainly study on the high efficiency of surface modified heat pipe.A surface modified efficient heat pipe was self developed. The inner surface in the evaporator section was coated with sintered porous layer, and the inner surface in condenser section was coated with Ni-P electroless plating. The surface modified efficient heat pipe exhibited better performance in enhancing heat transfer. Experiment results demonstrated that the internal overall heat transfer coefficient of surface modified efficient heat pipe increased 44%-58% compared with that of ordinary gravity heat pipe. In addition, the effect of powder size on the heat transfer performance of the heat pipe was studied and compared:when the porous layer thickness was the same, the heat pipe exhibited better performance in enhancing boiling heat transfer, which of sintered porous layer of the inner surface in the evaporator section was coated by appropriate meal powder. The effect of filling ratio and inclination angle on the heat transfer performance of surface modified efficient heat pipe was studied experimentally. The results showed that the comprehensive performance was optimal, when the filling ratio was 20% and the inclination angle was at 30°～45°.