竖直窄缝水工质常压过冷沸腾流动与传热分析

Investigation of Flow and Heat Transfer of Subcooled Boiling of Water in Vertical Narrow Channel at Atmosphere Pressure

以去离子水为工质,对常压下竖直窄缝通道内过冷沸腾流动与换热规律进行实验和数值模拟研究。对壁面气泡核化特点进行可视化实验分析,建立2 mm窄缝通道的壁面核化沸腾模型,包括:汽化核心密度、气泡脱离直径和气泡脱离频率关联式。以两流体模型为基础,结合壁面热量分配伦斯勒理工学院(RPI)模型以及壁面核化沸腾模型,建立竖直窄缝通道内过冷沸腾流动传热计算流体动力学(CFD)数值模型,对典型实验工况进行模拟分析,并与实验结果进行对比,两者吻合良好。

In the present paper, the flow and heat transfer characteristics of subcooled boiling of deionized water was investigated in a vertical rectangular narrow channel at atmospheric pressure. Flow visualization experiments were conducted to study the bubble nucleation on the heating wall. Based on the experimental observations, empirical models were proposed to correlate the active nucleation site density, bubble departure diameter and bubble departure frequency with given flow conditions for 2mm vertical narrow channel. Then, computational fluid dynamics （CFD） models were developed to simulate the subcooled flow boiling in the narrow channel by combining the two-fluid model, the Rensselaer Polytechnic Institute （RPI） wall heat flux partitioning model numerical results show excellent agreement with simulated. and the proposed bubble nucleation correlations. The the experimental data under the typical test conditions simulated.