[2E01-04] Boiling

[2E01] Experimental Study on Onset Condition of Boiling Entrainment from Falling Liquid Film with Gas Sheared Flow

*Raka Firman¹, Junpei Tabuchi¹, Tomio Okawa¹, Yuki Narushima², Hajime Furuichi², Kenichi Katono³ (1. The University of Electro-Communications, 2. Hitachi, Ltd., 3. Hitachi-GE Nuclear Energy, Ltd.)

Keywords:Annular Two-Phase Flow , Boiling Entrainment, Boiling System, Dryout, Experiment

Droplet entrainment from a liquid film is an important phenomenon to ensure safe operation in industrial boiling systems. Study on the entrainment in annular two-phase flow has been investigated by many researchers. However, the knowledge on the entrainment due to nucleate boiling is still insufficient. The authors categorized the boiling entrainment into two types and identified the dominant one called filament-type. The purpose of this study is to develop a model to identify the onset condition of the filament-type boiling entrainment. The visualization experiment has been conducted to clarify the boiling entrainment types and the influence of various parameters on the onset condition of the filament-type boiling entrainment. Then, we developed a model for the onset condition of boiling entrainment in a falling liquid film.