不凝縮ガスを含む蒸気泡の直接接触凝縮による気泡崩壊現象の可視化

抄録

Direct contact condensation (DCC) is a phenomenon that occurs when steam is injected into a subcooled water pool and is an integral part of many industrial devices. However, the actual phenomenon involves non-condensable gases in the steam, and there has been insufficient research on how non-condensable gases affect direct contact condensation. Therefore, the purpose of this study was to clarify the bubble collapse behavior of vapor bubbles containing non-condensable gas by DCC, and the bubble collapse behavior was confirmed using a high-speed video camera. The images show periodic bulging and necking, and the contraction speed at the point of necking was slower in the bubble plume with a higher air mass fraction. The number of microbubbles produced in the rising bubble plume was suppressed in the high air mass fraction plume. Thus, there is a negative correlation between the contraction rate of the bubble plume and the size of the generated bubbles.