Development of Unified Physical Model for Flow Boiling inside an Internally, Spirally, Grooved Tube, which is Applicable for Fluids with Much Different Thermophysical Properties

对水平波纹槽管内氨蒸发的流型和传热进行了实验研究。实验所用的工质为HCFC 123和氨水，它们的物理性质相差很大。本文研究了实验获得的流型信息和换热系数的特点，指出了现有模型和方法处理这一问题的局限性。对光滑管和槽管的流型转换特性进行了测量，并与现有的关联式进行了比较。 通过一个方程，提出了HCFC 123和NH3两种工质的分离流型与环状流型之间的过渡特性、环状流型/分离流型与雾状流型之间的过渡特性以及环状流型下的换热系数的新关联式。提出了处理不同物性流体的物理模型。

The flow pattern and heat transfer of evaporating ammonia inside a horizontal spirally grooved tube were experimentally investigated. Test fluids used were HCFC123 and ammonia, those physical properties are much different from each other. The characteristics of experimentally obtained flow pattern information and heat transfer coefficients were investigated.At first the limit of currently available model and method to treat this problem were shown through this discussion. The measured flow pattern transition qualities were compared with some available correlations both for a smooth tube and a grooved tube. The new correlations for the transition quality between separated and annular flow regimes, for the transition quality between annular/separated to mist flow regimes, and for the heat transfer coefficients in annular flow regime were proposed for both HCFC123 and ammonia by one equation. Also physical model to treat fluids with much different physical properties were proposed.