Visualized investigation on flow regimes for vertical upward steam-water flow in a heated narrow rectangular channel
- 作者：Junfeng Wang ; Yanping Huang ; hypgroup@163.com ; Yanlin Wang ; Mingliang Song
- 关键词：Flow regime ; Narrow rectangular channel ; Low pressure ; Low mass flux ; Vertical upward flow
- 刊名：Annals of Nuclear Energy
- 出版年：2012
- 期刊代码：1_03064549
- 类别：pw
- 出版时间：July, 2012
- 卷：45
- 期：Complete
- 页码：115-123
- 文件大小：1809 K
摘要
Flow regimes are very important in understanding two-phase flow resistance and heat transfer characteristics. In present work, two-phase flow regimes for steam-water flows in a single-side heated narrow rectangular channel, having a width of 40 mm and a gap of 3 mm, were visually studied at relatively low pressure and low mass flux condition. The flow regimes observed in this experiment could be classified into bubbly, churn and annular flow. Slug flow was never observed at any of the conditions in our experiment. Flow regime maps at the pressure of 0.7 MPa and 1.0 MPa were developed, and then the pressure effect on flow regime transition was analyzed. Based on the experimental results, the comparisons with some existing flow regime maps and transition criteria were conducted. The comparison results show that the bubbly transition boundary and annular formation boundary of heated steam-water flow were consistent with that of adiabatic air-water flow. However, the intermediate flow pattern between bubbly and annular flow was different. Hibiki and Mishima criteria could predict the bubbly transition boundary and annular formation boundary satisfactorily, but it poorly predicted churn zone in present experimental data.