Abstract:
In order to deeply analyze the influence characteristics of boiling crisis induced by boiling two-phase flow oscillation, this paper takes deionized water as the working medium, a single rod channel with a cross section of 19 mm×19 mm and an outer diameter of 9.5 mm at the center as the research object. Through visual experimental research on boiling two-phase flow characteristics under different thermal parameters, combined with the behavior of bubbles and vapor-liquid interface characteristics, the influence characteristics of boiling crisis induced by flow oscillations are analyzed. The results show that flow oscillation is easy to occur at low pressure, low mass flow rate and low inlet subcooling, which leads to the early occurrence of boiling crisis, and the critical heat flux is significantly lower than that under stable conditions; With the increase of wall heat flux, the two-phase flow patterns in the channel appear bubble flow, slug flow, combined slug flow, stirred flow, violent stirred flow and unstable annular flow; When the flow oscillates violently, there is reflux in the channel; When the boiling crisis occurs, the pressure drop fluctuation in the channel is the largest, and the corresponding flow pattern is unstable annular flow. Therefore, the flow oscillation in the single rod channel may lead to the early occurrence of boiling crisis.
