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采用CFD数值模拟的方法,建立了错流式单根中空纤维减压膜蒸馏过程的三维计算模型,对纤维膜表面不同位置的局部热量和质量传递特征进行了研究。研究结果表明,纤维膜表面的速度分布、温度分布、对流传热系数分布以及蒸发速率均随着位置的改变而改变,且具有相似的规律,在相位角60°到90°之间有最大值,而在相位角0°和180°附近其值较小;料液流速显著影响纤维膜表面的热质传递参数的分布,蒸发速率和传热系数均随着流速的提高而增大;传热系数随着真空度的提高而迅速降低。本研究结果加深了对中空纤维减压膜蒸馏过程的认识,对膜过程强化具有指导意义。
The CFD numerical simulation method was used to establish the three-dimensional calculation model of cross-flow single-walled hollow fiber decompression membrane distillation process. The local heat and mass transfer characteristics at different positions on the fiber membrane surface were studied. The results show that the velocity distribution, temperature distribution, convective heat transfer coefficient distribution and evaporation rate of fiber membrane change with the change of position, and have a similar rule, with the maximum value between 60 ° and 90 ° , While its value is smaller near 0 ° and 180 ° of phase angle. The flow rate of feed liquid significantly affects the distribution of heat and mass transfer parameters on the surface of fiber membrane. The evaporation rate and heat transfer coefficient increase with the increase of flow rate. Coefficients decrease rapidly with increasing vacuum. The results of this study deepen the understanding of hollow fiber vacuum membrane distillation process and provide guidance for the enhancement of membrane process.