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

对蒸氨在水平螺旋槽管内的流动和换热进行了实验研究。使用的测试流体是HCFC123和氨水，这两种液体的物理性质差别很大。对实验获得的流型信息和换热系数的特性进行了研究。首先，通过讨论指出了现有模型和方法的局限性。对光滑管和槽管的流型过渡品质进行了测量，并与现有的一些关联式进行了比较。对于HCFC123和氨气，提出了分离流区和环状流区之间的过渡质量、环状/分离流区和雾状流区之间的过渡质量以及环状流区的换热系数的新关联式。提出了处理物性差异较大的流体的物理模型。

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.