燕尾形轴向槽道热管的蒸发冷凝传热特性

建立了燕尾形轴向槽道热管蒸发和冷凝薄液膜传热特性理论模型,并对模型进行了数值求解.对蒸发薄液膜区液膜厚度、接触面温度和热流密度分布进行了分析,给出了汽液接触面蒸发/冷凝传热系数沿轴向的变化.研究表明:在蒸发薄液膜区域,薄液膜厚度沿槽壁方向呈线性增加；汽液接触面的温度在起点几乎和壁面温度相同,随着薄液膜厚度的增加而迅速降低；在薄液膜的起始段,热流密度快速达到最大值,随即迅速减小.蒸发段的蒸发传热系数大于冷凝段的冷凝传热系数,蒸发/冷凝传热系数在整个绝热段并不都为零.同时,通过实验验证了模型的正确性.

Evaporation and condensation heat transfer characteristics of heat pipe with axially swallow-tailed microgrooves

A theoretical model with a focus on the thin liquid film of the evaporator and condenser section is developed to predict the evaporation and condensation heat transfer characteristics of heat pipes with axially swallow-tailed microgrooves,which is then solved numerically.The thin film thickness,temperature of vapor-liquid interface and heat flux variations in the evaporating thin film region are analyzed.Meanwhile,the heat transfer coefficient of evaporation/condensation along the axial direction in the liquid-vapor interface is presented.The results indicate that the film thickness increases along the wall of microgroove in a linear fashion in the evaporating thin film region;the temperature of the vapor-liquid interface is equal to the wall temperature at the start point and decreases drastically with the increase of the film thickness;in the initial section of thin film,heat flux quickly gets to the maximum value and then rapidly decreases along the wall of microgroove.The evaporating heat transfer coefficient in the evaporator section is higher than the condensing heat transfer coefficient in the condenser section.In the adiabatic section,the heat transfer coefficient of evaporation/condensation is not all of zero.In addition,the accuracy of the numerical results is verified by the experimental data.