类单侧加热条件下有内置纽带的竖直上升圆形通道内过冷水的传热特性

Heat Transfer Characteristics of Subcooled Water in Circular Tubes With Twist Tapes Insert Under One-side Heating Conditions

为了研究国际热核聚变实验堆中偏滤器靶板的水冷换热结构的传热特性,用偏心电加热的方法来模拟工程实际中的单侧辐射加热。在系统压力P=3~5MPa、质量流速G=3000~8000kg/（m^2·s）、冷却通道壁面的平均热流密度q=2~5MW/m^2的参数范围内,对类单侧加热条件下,有内置纽带的竖直上升圆形通道内的水进行传热试验。分析了P、G、q以及内置纽带对传热特性的影响,在单相及过冷沸腾区将实验数据与典型的传热关联式进行对比,并提出了新的传热关联式。结果表明：在单相强制对流区,试验段的换热系数h主要受G和内置纽带的影响;在过渡沸腾区,h受到P、G、q和内置纽带的综合影响;而在充分发展过冷沸腾区,h主要受到q的影响。

In order to investigate the water cooling structure of the divertor target in the international thermonuclear experimental reactor（ITER）, the off-center electrically heating method was used to simulate the one-side heating condition in the engineering application. Tests on heat transfer characteristics of subcooled water were carried out in a circular channel with twisted-tape inserts under one-side heating conditions. The effects of parameters, including system pressure（P = 3~5 MPa）, mass flux（G = 3000~8000 kg/（m^2·s））, and heat flux（q = 2~5 MW/m^2） were discussed. The experimental data were compared with the typical correlations in single-phrase region and subcooled boiling region, respectively. New correlations in subcooled boiling region were proposed. The results show that the h is significantly affected by G and twisted tapes in the single phase region; the h is synthetically influenced by P, G, q and twisted tapes in the partially boiling region; the h is only affected by q in the fully developed boiling region.