文档介绍：强化管外降膜蒸发的机理分析
程彬李敏霞马一太
(天津大学热能研究所,天津,300072)
摘要在水平管降膜蒸发器中,利用强化管来替代一般换热管已经成为一种趋势。本文着重对强化管外
降膜蒸发过程的机理进行了研究,主要从强化管外降液膜的流动形式和强化管外换热模型两个方面入手,
研究表明:强化管外液膜流动的波动性与扰动性强于光滑管,进而液膜过热度与液膜内温度的一致性优于
光滑管;通过分析可知,分段模型更能揭示降膜蒸发过程换热的本质;强化管较光管不仅能够较大幅度的
提高换热系数,还能较早的进入沸腾蒸发阶段。
关键词强化管液膜流动换热模型
THE MECHANISM ANALYSIS OF THE FALLING FILM OUT OF THE
EVAPORATION ENHANCED TUBES
Cheng Bin Li Minxia Ma Yitai
(Thermal energy research institute,Tianjin University,Tianjin 300072)
Abstract In the falling film horizontal tube evaporator, it has e a trend to using the enhanced tubes to
replace general heat exchange tube . This paper focuses on analysis on evaporation mechanism of falling film
horizontal tube ecaporator, studying mainly fromb the liquid membrane flow mode out of the enhanced tubes and
heat transfer model out of the enhanced tubes. The research showed that the enhanced tubes were stronger for the
wave properties and the disturbance of the liquid membrane flow than the plain tubes, then, the consistency
between the degree of superheat of the liquid membrane and the temperature in the liquid membrane were better
than the plain tubes. The analysis revealed that subsection model could reveal the character of the falling film
evaporation more clearly; the enhanced tubes not only could improve the heat transfer coefficient relatively
substantially, bu