Experimental Investigation of the Local Heat Transfer in a Vertical Gas-Liquid Slug Unit
Heat transfer mechanism in two-phase flows and particularly in vertical slug flow is of high interest both for basic hydrodynamic research and for industrial applications. Two-phase slug flow is highly complicated and only a limited number of heat transfer studies have been carried out. The flow field around a single Taylor bubble propagating in a vertical pipe can be subdivided into three distinct hydrodynamic regions: the gas bubble surrounded by a thin liquid film, a highly turbulent liquid wake in the vicinity of the bubble bottom, and the far wake region. Experimental and theoretical works were presented during the last decades investigating the hydrodynamic parameters in each region. Due to the complexity and intermittent nature of slug flow the existing data on the heat transfer in slug flow is limited to a narrow range of operational conditions. To improve the understanding of the heat transfer mechanism in slug flow a new experimental setup was constructed. A part of the vertical pipe wall was replaced by a thin metal foil heated by electrical current. An IR video camera was used to determine the temporal variation of the instantaneous temperature field along the foil at two locations: at the thermal entrance region and at the upper part of the foil where thermal boundary is thicker. The video camera was synchronized with a sensor that determined the instantaneous location of the Taylor bubble. The results of the instantaneous heat transfer measurements along the liquid film and in the wake of the Taylor bubble can be correlated with the detailed velocity measurements carried out in the same facility (Shemer et al. 2007)1. The effect of the local hydrodynamic parameters on the heat transfer coefficient in each region is examined.
Two-Phase Flow Slug Flow Convcctive Heat Transfer Taylor Bubble IR Thermography
Valery Babin Lev Shemer Dvora Barnea
Tel Aviv University, Faculty of Engineering, Tel Aviv, 69978, Israel
国际会议
The 7th International Symposium on Measurement Techniques for Multiphase Flows(第七届国际多相流测试技术会议)
天津
英文
43-50
2011-09-17（万方平台首次上网日期，不代表论文的发表时间）