强制对流换热下竖直冰层融化特性研究

Simulation Investigation of Vertical Ice Layer Melting Characteristics under Forced Convection Heat Transfer

为研究热风加热下竖直冰层的融化特性,采用降膜流模型对竖直冰层融化过程中传热传质规律进行模拟研究。分析了冰层融化过程中内部温度变化,计算了不同工况下的融冰速率,研究了融冰水的流动和传热对冰层融化的影响特性,得到了冰层融化过程中固液相变层和融冰水Nu数随时间的变化规律。模拟结果和实验测量值、经典关联式结果吻合较好,验证了降膜流模型适应用于计算冰层融化过程。模拟结果表明融冰水的降膜流动换热在冰层融化过程中起到重要作用,在冰层融冰水为滴状流时冰层融化速率较低,而模拟工况下形成稳定膜状流后截面积0.16 m^2的冰层融化速率达到0.12 kg/min。

In order to investigate the melting characteristics of vertical ice layer using hot air as heat source,the falling film flow model was used to simulate the heat and mass transfer during vertical ice melting process. The internal temperature change during ice melting was analyzed,while the ice melting rates under different conditions were calculated. The influence of the flowing and heat transferring of ice melt water on ice layer melting characteristics were studied. The research results showed that the change of the Nu value of the solid-liquid phase change layer and the ice-melting water with time in the ice melting process were obtained. The simulation results were in good agreement with the experimental results and the classical correlation result. It verified that the falling film flow model was suitable for the calculation of ice melting process. The simulation results showed that the flow-through heat transfer of ice-melting water played an important role in the ice melting. The melting rate was low when the ice melt water was dripping flow. The melting rate of ice layer which cross-sectional area was 0. 16 m^2 reached 0. 12 kg/min when the ice melt water was falling film flow.