Research On Net Vapor Generation In Subcooling Under Rolling Condition In Vertical Channel

The determining of vapor bubble departure is important for the heat transfer and flow resistance calculation of heat exchanger, and also affect downriver characteristics of fluxion and heat transfer. It's an important link. The rolling motion is chosen as the ocean condition in this experimental study, we study on Natural Circulation subcooling vapor bubble departure in vertical channel. Water was used as the working medium, A visualized experiment is chosen to observe the phenomena under different conditions. Observe how vapor bubble departure changes with system pressure, inlet subcooling, heat power, rolling period, analysis on causation of the phenomena.Additional inertial force lead to the fluid flow rate fluctuation, the flow rate fluctuation affects the heat transfer. The position of vapor bubble departure is moving along the heating wall, and there are two stable positions, the highest one and the lowest one, the period of fluctuation and the rolling are uniform. The longer the rolling period is, the smaller the amplitude of vapor bubble departure fluctuation. According to the force effect on loop liquid under rolling condition, set up a model between flow rate and the rolling angle, find out the relationship between the rolling and the vapor bubble departure. We connect flow rate fluctuations with vapor bubble departure through the rolling. The conclusion is that the rolling lead to the flow rate fluctuation and the flow rate fluctuation affects the position of the vapor bubble departure.