多通道烘缸通道内气液两相流流型的数值模拟

Numerical Simulation of Gas-Liquid Two-Phase Flow Pattern in Channel of Multi-channel Cylinder Dryer

多通道烘缸矩形通道内的冷凝传热情况很难通过常规静态实验进行研究,为此,本研究采用FLUENT多相流模型中的VOF模型,对旋转状态下多通道烘缸内气液两相流流型和蒸汽冷凝过程进行了数值模拟。通过观察通道内流型、冷凝水体积分数和温度分布,得出了旋转通道内流体流动与传热的变化规律。结果表明,在通道旋转时,离心力与重力的相互作用对气液两相分布的均匀性有影响;通道表面从左到右的温度分布呈现从高到低的趋势;旋转通道中出现了规则分布的环丝状流,与实验结果相比,模拟结果更接近于烘缸的实际运行状态。

Condensation heat transfer in rectangular channel of multi-channel cylinder dryer is difficult to be studied by conventional static experiments.Therefore,the VOF model in Fluent multiphase flow model is used to simulate the gas-liquid two-phase flow pattern and steam condensation process in multi-channel cylinder dryer under rotating condition.By observing the flow pattern,condensate volume fraction and temperature distribution in the channel,the variation law of fluid flow and heat transfer in the rotating channel were obtained.The results show that the interaction between centrifugal force and gravity has an effect on the uniformity of gas-liquid two-phase distribution when the channel rotates.And the temperature distribution on the channel surface from left to right presents a trend from high to low.Furthermore the annular filamentary flow with regular distribution appears in the rotating channel,which is closer to the actual operation state of the dryer compared with the experiment.