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本文对水平矩形槽道表面的池沸腾传热进行了实验研究。工质系水和乙醇,压力为大气压。结果表明,糟道表面是低温差下强化沸腾的良好加热面,传热系数比平表面池沸腾高数倍乃至上十倍。强化机理在于槽道壁面增大了泡底微层液膜的蒸发面积,延长了微层蒸发时间。本文以汽泡生长的物理模型为基础分析了上述机理,并综合大量的实验数据利用多元线性回归分析在计算机上整理出了槽道表面池沸腾的自然对流区和旺盛核沸腾区的两个传热准则方程式。此外,采用曲面拟合,求取极值等手段得到了实验范围内的最佳形状参数。
In this paper, the experimental study of pool boiling heat transfer on the surface of horizontal rectangular channel is carried out. Working fluid is water and ethanol, the pressure is at atmospheric pressure. The results show that the surface of the absurd is a good heating surface for enhanced boiling at low temperature and the heat transfer coefficient is several times or even ten times higher than that of a flat surface pool. The strengthening mechanism lies in that the wall of the channel increases the evaporation area of the bottom micro-layer liquid film and prolongs the micro-layer evaporation time. In this paper, based on the physical model of bubble growth, the above mechanism is analyzed. Based on a large number of experimental data, multiple linear regression analysis is used to sort out two convection areas of the basin surface pool boiling natural nucleation and vigorous nucleate boiling area Heat criteria equation. In addition, the best shape parameters in the experimental range are obtained by means of surface fitting and extreme value obtaining.