管路预冷的高速再淹没传热模型及数值研究

Numerical research on high velocity reflooding heat transference for pipeline cooling down

通过分析竖直管路高速再淹没传热过程的流型及沸腾曲线,研究了低温流体预冷竖直管路的高速再淹没传热特性,构建了一组涵盖主要传热工况的管壁与低温流体间的传热模型,耦合了管壁的释热方程和低温流体间的流动传热方程.修正了反环状流膜态沸腾的Bromley计算式,并针对竖直管路的液氮预冷实验工况进行数值模拟,计算结果较好反映了竖直管路的预冷降温过程.特别是在管壁温度突降点的预测上,其温度预测结果与实验数据相一致.

By analyzing the flow pattern and boiling curve of high velocity reflooding process in vertical pipeline, the flow and heat transfer characteristics of cooling down with cryogenic liquid were analyzed. Moreover, one set of heat transfer models between the pipeline wall and the cryogenic liquid were established, which coupled the heat release equation of the circulation loop and the flow and heat transfer equations of the cryogenic liquid. Adopted a modified Bromley correlation for predicting the inverted annular boiling, numerical simulation was performed on the cooling down experiments of vertical pipeline with liquid nitrogen from reference. The predicted results show a be approximation with the experimental data. Especially in the inflection point of wa prediction temperature agreed with the experimental value well.