射流式泡沫发生器气液两相流流动规律研究及结构优化

发布时间：2018-06-25 10:59

本文选题：射流式泡沫发生器 + 气液两相流　；参考：《东北石油大学》2017年硕士论文

【摘要】：本文以射流式泡沫发生器为模型,其结构简单,安装维护方便,产泡能力强,且能根据现场实际情况产出不同倍数的泡沫。根据某油田矿场水平井冲砂作业的射流式泡沫发生器外形尺寸,运用Solid Works建立射流式泡沫发生器结构模型,采用商业计算流体软件FLUENT模拟其内部气液两相流流场运动规律,并分析不同气液比对其内部气相体积分布影响;结合挡板式泡沫发生器的挡板结构,在喉管前端设置一圆形凸台挡板,研究不同挡板出口直径对泡沫发生器内部气液两相流流动规律及气相分布影响。通过数值计算表明,基液流经喷头时,由于过流断面逐渐减小,基液流速增大,静压降低;喷头出口附近的气体被高速射流卷走,在吸入室形成负压,并逐渐形成上下对称涡旋方向相反的涡流;气液两相经过喉管时,有管壁剪切作用,气液两相互相渗入,作用力变大;泡沫发生器的扩散管横截面面积逐渐增大,均匀的气液两相流在扩散管内流速降低,压力逐渐升高。随着含气量的增大,泡沫发生器内气相体积分数逐渐提高,且相同气相体积分数所占的区域大小也随含气量的增大而增大;另外,随着含气量的增大,泡沫发生器出口处气相体积分数逐渐升高,泡沫发生器的发泡效率有所改善。挡板可减小涡流影响范围,抑制了喉管内气相在压差作用下回流至吸入室的现象,使吸入室内的气相体积分数降低;而进入喉管内的气相与液相之间的动压差减小,在喉管壁面剪切作用下,气相与液相相互掺混区域缩小,可降低因相间扰动作用而迫使界面张力较高的气泡破裂,使得喉管和扩散管内的气相体积分数增大,泡沫发生器的发泡效率得到提升。
[Abstract]:In this paper, a jet foam generator is used as a model, which has the advantages of simple structure, convenient installation and maintenance, strong foaming ability and the ability to produce foam with different multiples according to the actual situation in the field. According to the shape size of jet foam generator in horizontal well of a certain oilfield, the structure model of jet foam generator is established by using solid works, and the movement law of gas-liquid two-phase flow field is simulated by commercial computational fluid software fluent. The influence of different ratio of gas to liquid on the volume distribution of gas phase is analyzed, and a circular bulkhead baffle is arranged at the front of the throat pipe in combination with the baffle structure of the baffle type foam generator. The effects of different baffle outlet diameters on gas-liquid two-phase flow and gas phase distribution in foam generator were studied. The numerical calculation shows that when the base liquid flows through the nozzle, the velocity of the base liquid increases and the static pressure decreases because the cross section decreases gradually, and the gas near the nozzle outlet is swept away by a high speed jet and forms a negative pressure in the suction chamber. The vortex with opposite direction of the upper and lower symmetric vortex is gradually formed. When the gas-liquid two-phase passes through the throat pipe, there is shear effect on the pipe wall, the gas-liquid two-phase infiltrates into each other, and the interaction force becomes larger, and the cross-section area of the diffusive tube of the foam generator increases gradually. The uniform gas-liquid two-phase flow velocity decreases and the pressure increases gradually in the diffusion tube. With the increase of gas content, the gas volume fraction in foam generator increases gradually, and the region occupied by the same gas volume fraction also increases with the increase of gas content, in addition, with the increase of gas content, The volume fraction of the gas phase at the exit of the foam generator increases gradually, and the foaming efficiency of the foam generator is improved. The baffle can reduce the influence range of eddy current, restrain the phenomenon that the gas phase reflux to the suction chamber under pressure difference, and decrease the volume fraction of the gas phase in the suction chamber, while the dynamic pressure difference between the gas phase and the liquid phase entering the pipe decreases. Under the shear of throat wall, the mixing region between gas phase and liquid phase is reduced, and the bubble with high interfacial tension is forced to break down due to phase disturbance, which increases the volume fraction of gas phase in the pipe and diffusion pipe. Foaming efficiency of foam generator is improved.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE358.1

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