[1G08-12] Multiphase Flow

[1G08] Study on the Effect of Air Flowrate and Subcooled Degree on Boiling Entrainment Rate from a Liquid Film Flowing Downwards on a Vertically Heated Surface

*Raka Firman Baskara Permana¹, Tomio Okawa¹, Nade Kaito¹, Yuki Narushima², Kenichi Katono², Hajime Furuichi² (1. The University of Electro-Communications Tokyo, 2. Hitachi, Ltd.)

Keywords:Annular Two-Phase Flow, Boiling Entrainment Rate, BWR

Boiling entrainment in annular two-phase flow is associated with the occurrence of the liquid film dryout in the annular two-phase flow. There are some probable parameters that may affect the boiling entrainment rate. Therefore, experiments to measure the effect of air flow rate and subcooled degree on boiling entrainment rate were carried out from a liquid film flowing downwards on a vertical heated surface. Water and air were used as the test fluid and all the experiments were performed under the atmospheric pressure condition. In the experiments, collector cup located in the exit end of the test section was used to collect and measure the exit film flow rate and then the boiling entrainment rate was calculated. It was found that the boiling entrainment rate increased as the subcooled degree decreased. It was also found that the airflow influenced on suppressing the amount of boiling entrainment.