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为了弄清在窄缝环形流道中气泡的形成、聚合和变形的特性 ,以及气泡在聚合变形之后对传热特性的影响 ,在常压下用蒸馏水对窄缝间隙为 0 75mm的垂直环形流道 ,进行了可视化的流动沸腾传热实验研究 ;实验段的有效加热长度为 90 0mm ,其加热方式为单面内侧加热 ,实验的流量变化范围为 1 667× 1 0 - 5m3/s至 5 833× 1 0 - 5m3/s。实验得到了在不同质量流密度和热流密度下窄缝流道中的沸腾传热系数随干度变化的分布。通过与常规流道中的沸腾传热系数的比较 ,得到了在窄缝环形流道中沸腾传热系数比常规流道中的沸腾传热系数约高 1 5 %的结论。另外通过用高速摄像机对可视化的垂直环形流道中的流型进行的拍摄研究 ,分清了存在在窄缝环形流道中的四种流型
In order to clarify the formation of air bubbles in the narrow annular channel, the characteristics of polymerization and deformation, as well as the bubble after polymerization deformation on the heat transfer characteristics of the atmospheric pressure with distilled water on the slit gap of 75mm vertical annular flow channel , The experimental study on the flow boiling heat transfer was carried out. The effective heating length of the experimental section was 90 0 mm, and the heating method was single-side inner heating. The experimental flow ranged from 1 667 × 10 -5 m 3 / s to 5 833 × 1 0 - 5m3 / s. The distributions of the boiling heat transfer coefficients with the variation of dryness in the narrow channel were obtained under different mass flow and heat flux. By comparing with the boiling heat transfer coefficient of the conventional flow channel, the conclusion that the heat transfer coefficient of boiling in the narrow annular flow channel is about 15% higher than that of the conventional flow channel is obtained. In addition, by using the high-speed camera to visualize the flow pattern in the vertical annular flow channel, four kinds of flow patterns existing in the narrow annular flow channel are distinguished