On Upward Flow of Gas-Liquid Mixtures in Vertical Tubes : 3rd Report, Heat Transfer Results and Analysis

抄録

Experimental results of the average heat transfer coefficient are presented for two-component two-phase upward flow in a vertical tube, over a range of values of the liquid flow rate, void fraction and liquid Prandtl number. An empirical equation describing these results is developed. This relation expresses the average Nusselt number as a function of the Prandtl number of the liquid phase and a Reynolds number based on the equivalent mean velocity of the liquid phase (defined in the 2nd report). A theoretical prediction of the heat transfer coefficient is also presented. This is based on assuming the eddy diffusivity for momentum in the liquid film to be equal to that for heat. The results are in good agreement with the experimental data. A discussion of the liquid film resistance to heat transfer is also included for annular flow of single-component two-phase flow.