节能型立式热虹吸再沸器的模拟

为了提高再沸器的用能效率，特将固体颗粒引入立式热虹吸再沸器的管程形成气－液－固多相流系统，以强化传热，并提出了该节能型立式热虹吸再沸器的数学模型。模拟计算表明，流态化技术的引入能够强化再沸器的传热，减小换热面积或系统的有效能损失。颗粒的密度对传热的影响较大，其增加可使管内传热系数增大；随着固含率的增加，管内传热系数增大；随着粒径的增加，管内传热 数先增加后减小，有一极大值，颗粒密度的增加可使该极值增大并出现得更早。

Simulation of the Novel Vertical Thermosiphon Reboiler for Energy Saving

In order to increase the efficiency of reboilers, solid particles were introduced into the tube-side of the reboiler forming gas-liquid-solid multi-phase flow system to enhance heat transfer. A mathematical model of the reboiler was presented. The simulation results showed that the heat transfer coefficient of tube side in the reboiler was greatly enhanced and the system exergie could be reduced by adding solid particles. The influence of particle density, diameter and conductivity was investigated. The particle density offers significant effect on heat transfer, while particle heat conductivity has little effect. The heat transfer coefficient of tube-side is increased with increasing the particle density and diameter. However, there is a maximum value in the variation of heat transfer coefficient of tube-side with particle diameter when adding heavier particles. The greater the particle density, the greater the maximum, and the earlier it emerges. Furthermore, the heat transfer coefficient of tube-side also is increased with the increase of solid phase holdup.