Abstract:

Numerical simulation of cooling heat transfer to supercritical methane was investigated with Lam-Bremhorst low Reynolds turbulence model in a vertical circular tube，and the influences of flow direction，mass flow rate，heat flux and buoyancy were studied.The results showed that heat transfer coefficient of supercritical methane increased with mass flow rate increasing;heat transfer coefficient increased as heat flux increased in the gas-like region，while it was irrespective of heat flux in the liquid-like region;heat transfer coefficient was free of flow direction in the gas-like region，while heat transfer coefficient in upward flow was high than that in downward flow;density variations made heat transfer coefficient increase in gas-like region，while in the liquid-like region，heat transfer coefficient was increased in upward flow and decreased in downward flow.

Key words:

超临界甲烷, 冷却换热, 竖直圆管, 数值模拟

摘要：

应用Lam-Bremhorst低雷诺数湍流模型对超临界甲烷在竖直管内的冷却传热进行了数值模拟，研究了质量流量、热通量、流动方向及密度变化对传热系数的影响。结果表明，竖直圆管内超临界甲烷冷却传热系数随质量流量的增加而增加;在似气体区传热系数随热通量的增大而增加，而在似液体区热通量对传热系数几乎没有影响;流动方向在似气体区对传热系数几乎没有影响，而在似液体区上升流的传热系数大于下降流的传热系数;密度变化在似气体区使传热系数增加，而在似液体区使上升流的传热系数增加，使下降流的传热系数减小。

关键词:

超临界甲烷, 冷却换热, 竖直圆管, 数值模拟