[3J01-04] Boiling & Condensation

[3J02] Experiments on the onset criteria of boiling entrainment from a falling liquid film

*Junpei Tabuchi¹, Raka Firman¹, Tomio Okawa¹, Yuki Narushima², Hajime Furuichi², Kenichi Katono² (1. UEC, 2. Hitachi)

Keywords:Boiling water reactor, Dryout, entrainment, experiment

The accurate prediction of droplet entrainment in BWR is of significant importance because it is closely involved in the occurrence of dryout. Especially, the accurate prediction of the boiling entrainment phenomenon is required to improve the accuracy of the boiling entrainment rate. In this experiment, as a first step for the model development, runs of a visualization experiment were conducted to clarify the mechanism of boiling entrainment and the influence of various parameters on the onset criteria for boiling entrainment. From the visualization experiment, we observed the droplet entrainment phenomena caused by nucleate boiling and found that there were two types of processes by which droplet entrainment occurs.