面向电主轴定子冷却的热管流动与传热数值模拟

High-speed motorized spindle is the main heat source of CNC machine tools, which seriously affects machining accuracy. Compared with the traditional stator water jacket, applying the heat pipe to the stator of the electric spindle to dissipate heat has the advantages of higher efficiency and no pump power consumption. The loop thermosyphon with special structure is proposed for high-speed motorized spindle stator cooling in this paper. A numerical calculation method for the vapor-liquid two-phase flow and phase change heat transfer in the heat pipe tube is established, the proposed method is verified through experimental results, and this method is used to study the influence of different working fluids (n-pentane, ethanol, water) and heating power on flow and heat transfer performance of heat pipe. The results show that the numerical simulation method can accurately capture the gas-liquid two-phase flow pattern and phase change thermal process in the tube, which is in good agreement with the experimental data. A condensate film is formed in the condensation section when the working fluid is n-pentane and ethanol, and the liquid film thickness of ethanol is about 20 μm smaller than that of n-pentane under the same working conditions. Droplets are formed in the condensation section when the working fluid is water, which leads to higher heat transfer coefficient. The thermal resistance of the heat pipe with water as the working fluid under the heating power of 90 W is about 35.2% and 11% lower than that of n-pentane and ethanol, respectively.