制冷用水平降膜式蒸发器研究进展

降膜式蒸发器目前在牛奶、制药、化工、海水淡化等行业取得了较为广泛的商业应用,它从上世纪90年代以后开始应用于制冷空调系统。目前针对制冷用水平降膜式蒸发器的研究目的主要是明确各个参数对蒸发器传热性能的影响以及他们之间的联系,由于降膜式蒸发器的独特结构和内部传热传质的复杂性,这些研究尚处于初步阶段。在介绍其工作原理的基础上,针对水平降膜式蒸发器,着重讨论了布液器的结构与高度、管束(包括管径、管排数、管道表面形状)、制冷剂(流型、流量)等参数对其性能的影响。由于经验关联式在实际应用中的巨大优势,还总结了前人提出的关联式及其适用的范围,文章将为制冷用降膜式蒸发器的进一步研究和应用提供参考。

Research Progress of Horizontal Falling Film Evaporator in Refrigeration System

The widely applications have been achieved for falling film evaporators in the fields of pharmaceutical, chemical, ocean desalinization industries. However, the employment in the refrigeration and air condition was just after 1990. As so far, the researches for falling film evaporator were mainly focused on figuring out the influence of the parameters, as well as the coupling among them. Nevertheless, due to the special configuration and complexity of heat and mass transfer in the falling film evaporator, the researches were still on the preliminary level. On the basis of the illustration of the operation mechanism, this paper discussed about the influence of configuration and height of the liquid feeder, evaporation tube (including radius, the bundles, enhanced surface), working fluid (flow pattern, flow rate) on the performance of the horizontal falling film evaporator. Consideration the great advantages of the empirical correlation in the practices, the heat transfer correlations and applied ranges were also presented. This paper can be a reference of future researches.