洗涤冷却室气液分离空间内液滴重力分离数值研究

Numerical study of gravity separation of droplets in gas-liquid separation space of scrubbing-cooling chamber

在Euler-Lagrange三维坐标系下,建立了液滴重力分离模型.利用该模型模拟了气化炉洗涤冷却室气液分离空间内的气液两相流动.揭示了液滴的运动规律,分析了气液分离空间高度、气流速度以及液滴初始速度对液滴分离效率的影响.研究结果表明:液滴在飞溅进入气液分离空间后作减速运动,越小尺寸液滴的减速越为明显;液滴的分离效率随着气液分离空间高度的增加而提高并趋于稳定;在相同液滴初速度以及相同气液分离空间高度下,随着气流速度的降低,液滴的分离效率反而增大;随着液滴初始速度的提高,获得最大液滴分离效率所需的气液分离空间高度增加.在考虑液滴碰撞效应后,计算得到的液滴分离效率有所提高.

The droplets were separated from syngas by gravity in the gas-liquid separation space of scrubbing-cooling chamber in the coal-water-slurry gasifier.The gravity separation model of droplet is established based on the Euler-Lagrange approach.The gas-liquid flow in the gas-liquid separation space was simulated.The effects of separation space height,gas velocity and initial velocity of droplets on the separation efficiency are discussed in detail.The results show that the droplets decelerate after entering the gas-liquid separation space.The smaller the diameter of droplets,the more obvious the deceleration.With increase of the separation space height,the separation efficiency of droplets rapidly rises and then gradually tends to be stable.For the same height of gas-liquid separation space and same initial velocity of droplets,the separation efficiency increases with decreasing of gas velocity.The higher height of gas-liquid separation space is needed to get the maximum efficiency with the increase of the initial velocity of droplets.The separation efficiency increases when the collision of droplets is taken into account.