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用高速摄像等方法研究了有压模化介质在单一垂直矩形窄缝流道内的气泡形态和传热情况 ,发现窄缝流动沸腾换热强化的原因在于流道尺寸较小 ,气泡的形状发生变化 ,增加了界面体积浓度 ,并强化了对加热面附近的扰动 ,使换热有所强化。通过与实际测量的壁温数据进行比较 ,发现用于计算大流道和池过冷沸腾换热的 Rohsenow关系式预测窄流道内高热流密度下的过冷流动沸腾换热的误差不大 ,但对于较低热流密度下的过冷流动沸腾时误差较大 ;通过最小二乘法对 Rohsenow关系式进行修正后 ,误差低于± 2 5 %。
The bubble shape and heat transfer in a single vertical narrow rectangular channel with a die-casting medium were studied by high-speed imaging. The reason for the enhanced boiling heat transfer in a narrow slot was that the size of the flow channel was small and the shape of the bubble changed , Increasing the volume concentration of the interface and intensifying the perturbation near the heating surface so that the heat exchange is strengthened. By comparing with the measured wall temperature data, it is found that the Rohsenow equation for calculating the subcooled boiling heat transfer in the runoff and in the pond is less error-predictive than the subcooled flow boiling heat transfer in the narrow flowpath The error is larger when the subcooled flow boils at a lower heat flux density, and the error is less than ± 25% after the Rohsenow relation is corrected by the least square method.