低温流体在竖直通道中降膜蒸发研究进展

发布时间：2019-03-07 20:07

【摘要】：降膜蒸发作为一种高效传热传质技术,已经在空分领域得到了应用。本文介绍了空分膜式主冷凝蒸发器的原理和特点,从波状特性和破断特性方面阐述了下降液膜的动态特性,总结了入口流量、壁面结构、工质组分和热流密度因素对传热传质的影响,重点介绍了低温液氮在大空间平板上降膜过程的临界热流密度规律和过热壁面再湿润动态特性,并对现有竖直通道内降膜蒸发过程换热关联式进行了归纳。由于低温工质物性和通道结构的特殊性,已有的常温工质换热关联式应用于空分膜式主冷凝蒸发器的传热设计还存在较大差距。最后指出小传热温差条件下,复杂狭窄通道内低温流体降膜蒸发过程需要进一步研究。
[Abstract]:Falling film evaporation, as an efficient heat and mass transfer technology, has been applied in the field of air separation. In this paper, the principle and characteristics of the main condensing evaporator with air separation film are introduced. The dynamic characteristics of the falling liquid film are expounded from the aspects of wave characteristics and breaking characteristics, and the inlet flow rate and wall structure are summarized. The effects of working fluid composition and heat flux on heat and mass transfer are discussed. The critical heat flux and the dynamic characteristics of superheated wall rewetting are introduced in detail in the falling film process of low temperature liquid nitrogen on a large space plate. The heat transfer correlation of the falling film evaporation process in the vertical channel is summarized. Due to the particularity of low temperature working fluid physical properties and channel structure, there is still a big gap in the heat transfer design of the existing normal temperature working fluid heat transfer correlation used in the main condensing evaporator with air separation film. Finally, it is pointed out that the process of falling film evaporation of low temperature fluid in complex narrow channel needs to be further studied under the condition of small heat transfer temperature difference.
【作者单位】：江苏建筑职业技术学院建筑设备与市政工程学院;西安交通大学能源与动力工程学院;
【基金】：江苏建筑职业技术学院校级课题(JYA315-13)项目资助~~
【分类号】：TQ051.6

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