空气冷却式膜蒸馏构型的传热分析

在膜蒸馏的不同构型中，直接采用环境空气作为冷却媒介的空气冷却式构型很大程度上简化了系统配置。在强化传热的条件下，其跨膜通量与水冷构型接近。对空气冷却式膜蒸馏构型的传热过程进行理论分析，并通过量化分析各参数对膜蒸馏传热性能的影响，构建综合的传热模型。引入关联热阻系数这一概念，用以量化空气冷却的参数对膜蒸馏过程总传热系数的抑制作用。通过模拟计算研究了冷凝板导热系数、空气流速、冷凝板肋化系数、料液温度等参数对膜蒸馏传热性能的影响，并分析和量化多参数对关联热阻系数的综合影响。结果表明冷凝板导热系数、空气流速、冷凝板肋化系数是影响关联热阻系数的重要因素，各参数对膜蒸馏传热性能的综合影响得以量化。以上研究为后续传质模型的研究提供了指导。

Investigation of the heat transfer analysis of air-cooled membrane distillation configuration

Among the various configurations of membrane distillation, air-cooled configuration that directly uses ambient air as the cooling medium greatly simplifies the system design. Under the condition of enhanced heat transfer, the transmembrane permeate flux is comparable with that of the water-cooled configuration. In this study, the theoretical analysis of heat transfer of air-cooled membrane distillation configuration was conducted. Besides, a fundamental heat transfer model was coupled by analyzing the influence of parame-ters on the heat transfer performance of membrane distillation. More importantly, we introduce the con-cept of relative thermal resistance coefficient to characterize the inhibitory effect of air-cooled condition on the overall heat transfer coefficient of the membrane distillation process. Additionally, the effects of thermal conductivity, rib effect coefficient of condensing plate, air flow rate, and feed temperature on the membrane distillation performance were investigated by simulated calculation. The influence of parameter coupling on the relative thermal resistance coefficient was analyzed. The results show that the thermal conductivity, rib effect coefficient of condensing plate and air flow rate have major impacts on the relative thermal resistance coefficient. The influence of various parameters on the heat transfer performance of membrane distillation can be quantified. The above research provides guidance for the following study of mass transfer model.