均匀加热窄通道内环状流液膜厚度和换热系数的预测模型

A Prediction Model for Liquid Film Thickness and Heat Transfer Coefficient of Annular Flow in a Narrow Channel with Uniform Heating

为探究窄矩形通道内环状流的流动传热特性,根据液膜的质量、动量和能量方程以及汽芯的动量方程建立了环状流的预测模型。对该模型进行数值求解,得出了窄矩形通道内环状流区域的沸腾换热系数,并分析了热流密度、质量流速和矩形通道尺寸对液膜厚度的影响。结果表明:该模型能很好地预测沸腾换热系数,其误差在±30%以内,且热流密度和矩形通道的尺寸对液膜厚度的影响效果比较大。

In order to research the heat transfer characteristics of annular flow in the rectangular narrow channel, a mathematical model of annular flow in rectangular narrow channel is developed based on the mass, momentum and energy conversation equations of liquid film, as well the momentum conversation equation of vapor core. Through numerically solving the closure equations, the boiling heat transfer coefficients of annular flow in the rectangular narrow channel is obtained, and the effects of heat flux, mass flow rate and rectangular channel size on the liquid film thickness are analyzed. The results show that the present model can well predict the two-phase heat transfer coefficient, and the deviation is within 4-30%. The heat flux and rectangular channel size have a big effect on the liquid film thickness.