破泡结构对洗涤室内气泡特性的影响研究

STUDY ON INFLUENCE OF BUBBLE-BREAKING STRUCTURE UPON THE GAS BUBBLE PROPERTIES IN THE SCRUBBING CHAMBER

为优化控制水煤浆气化工艺中洗涤冷却室内的气泡特性,强化洗涤传热、传质效果,采用流体体积模型(VOF)对冷却室内的冷态气液两相流动进行数值模拟,分析了破泡板对气液两相流动、气泡平均湿周和气含率的影响,比较了破泡板平行、交错2种开孔方案的破泡效果。结果表明,增加破泡板能减小液位波动、破碎和扩散气泡,有利于增大气泡湿周;破泡板上交错布孔比平行布孔更有助于均布纵截面平均气含率。

In order to optimize the control of gas bubble properties in the scrubbing-cooling chamber used for gasification of coal-water slurry,strengthening the effectiveness of heat and mass transfer in the scrubbing,a numerical simulation of cold-state gas-liquid two-phase flow in the cooling chamber has been carried out by using the volume of fluid model,the influence of bubble-breaking plate upon the gas-liquid two-phase flow,the average wetted perimeter of gas bubbles,and the void fraction being analysed,and the bubble-breaking effectiveness of two schemes of arranging holes on the bubble-breaking plate in parallel and in criss-cross being compared.Results show that the increase of bubble-breaking plates can decrease the fluctuation of liquid level,can break and spread the gas bubbles,and is helpful to increase the wetted perimeter of gas bubbles;the arrangement of holes on bubble-breaking plate in criss-cross is more beneficial to uniform distribution of the average void fraction on the longitudinal cross-section.