环形窄缝通道内弥散流换热的理论计算

在充分考虑干涸后弥散流区域液滴、过热蒸汽以及加热壁面间的各换热过程的基础上，提出了一个预测环形通道弥散流换热的理论模型，同时针对1．0、1．5和2．0mm间隙的环形实验段进行了干涸后换热实验研究．计算结果表明：在弥散流中，蒸汽与加热壁面间的强迫对流换热起主导作用，占总换热量的90％左右；液滴与壁面接触换热、液滴与蒸汽问的换热对总体换热有一定影响；在该研究工况范围内，可以忽略辐射换热的影响．理论模型的预测值与实验值符合较好，说明该理论模型可以用来预测环形窄缝通道内的干涸后换热。

Theoretical Prediction on Post-Dryout Heat Transfer in Annular Channels

A non-equilibrium analysis model was developed for predicting post-dryout heat transfer in bilaterally heated narrow annuli based on detailed analysis of heat exchange processes arising among droplets, superheated vapor and heated walls. Experiment study was also conducted using annular channels with gap sizes of 1.0 mm, 1.5 mm and 2.0 mm. Comparison of results indicates that the model prediction agrees well with the experimental data. Moreover, the forced convection between the heated wall and vapor leads to about 90% of the total heat transfer amount. Further, both heat transfers between droplets and wall and between droplets and superheated vapor have indispensable contribution. In addition the radiation heat transfer can be neglected because of its small contribution to the total heat transfer.