蒸发冷却汽轮发电机中两相流型的过渡准则

蒸发冷却汽轮发电机中的关键问题是线棒温度分布和两相压降的预测，而准确的流型判断准则是解决这些问题的前提。为了得到适用蒸发冷却汽轮发电机定子绕组内冷条件下的两相流型过渡准则，文中针对汽轮机定子空心导线的结构特点，搭建起冷却介质R113的水平两相流实验台，在110~140 kPa、1.72~19.78 g/s的条件下，对流型的过渡进行了实验研究。实验结果与常用的流型过渡计算方法比较后，发现Taitel & Dukler方法和Weisman方法不适用于定子空心导线，误差很大，Barnea方法与实验条件相似，误差比较小。最后，在Taitel & Dukle和Barnea方法的基础上，分析了不同流型转换时的受力情况，并结合汽轮发电机定子绕组内冷的特点，简化了导线尺寸与介质物性的影响，得到适于汽轮发电机定子绕组蒸发内冷条件下的流型过渡准则。

Research on Two-phase Flow Pattern Transition in the Evaporative Turbine Generator

The key problems of the evaporative turbine generator are the stator bar's temperature field and the refrigerant's two-phase flow pressure drop, and an accurate flow pattern transition correlation is essential to solve these. In order to get an applicable transition correlation, a horizontal two-phase flow experimental table was established according to the stator hollow conductor's structure, and the research was made at 110-140kPa with refrigerant R113's mass flux of 1.72-19.78g/s.The comparison between experimental data and results of common flow pattern transition correlations shows that the Taitel & Dukler correlation and the Weisman correlation have big errors and are not applicable for stator hollow conductors, while the Barnea correlation has small errors since it is got under a similar experimental condition. Finally, forces of each flow pattern were analyzed based on the Taitel & Dukle correlation and the Barnea correlation, and influences of the hollow conductor's dimension and the refrigerant's properties were simplified by considering the stator bar's evaporative inner-cooling characteristics, and then an applicable flow pattern transition correlation was got for the evaporative turbine generator.