基于两相流型的立式热虹吸式再沸器结果分析

Result analysis of vertical thermosyphon reboiler based on two-phase flow pattern

关键词:  再沸器  气化流型  扭带  强化传热

Key words:  reboiler  flow pattern  twisted tape  heat transfer enhancement

摘要:

立式热虹吸式再沸器是乙二醇再生与回收系统中的核心设备,针对再沸器气化率低、管程出口管线因气化流型发生振动等问题,采用软件Aspen EDR对管程出口管内径分别为200 mm和300 mm进行了设计对比,通过在换热管内插入扭带对再沸器进行了强化传热。研究了管程出口管内径大小、扭带扭率及扭带厚度变化对气化率和气化流型的影响规律。结果 表明:不同出口管径下,管内气化流型转换趋势基本一致；再沸器管程出口管内径为200 mm时,其总体运行效率更高；通过插入扭带,提高了再沸器的总传热系数和气化率,优化了管内的气化流型,提高了再沸器的换热性能；扭带扭率越低,再沸器的传热效率越优；当扭带扭率为4.76、扭带厚度为1 mm时,再沸器的综合强化效果最佳。

Abstract:

The vertical thermosiphon reboiler is the core equipment in the ethylene glycol regeneration and recovery system. Aiming at the problems of low vaporization fraction of the reboiler and vibration of the flow pattern for the outlet tube,the design of the outlet tube diameters of 200 mm and 300 mm is compared by using the software Aspen EDR. The heat transfer enhancement of the reboiler has done by inserting twisted tape into the heat exchange tube. The influences of the outlet tube diameter, the twist rate of twisted tape and the thickness of twisted tape on the reboiler vaporization fraction and the flow pattern in the tube are studied The results show that the flow pattern range line is basically the same under different outlet tube diameters; when the outlet tube diameter of the reboiler tube side is 200 mm, the overall operating efficiency is higher than that of the tube diameter of 300mm; by inserting twisted tape, the total heat transfer coefficient and vaporization fraction of the reboiler are improved, the flow pattern in the tube is optimized, and the heat exchange performance of the reboiler is improved; the lower twist rate of the twisted tape, the better the heat transfer efficiency of the reboiler; the comprehensive strengthening effect of the reboiler is the best when the thickness of the twisted tape is 1 mm and its twist rate is 4.76.