管道清管器旁通流场三维数值模拟分析

摘要

为探究清管器与管道内壁间存在旁通时流场分布情况, 进而为提升其清管效率和通过安全性提供依据, 利用ICEM CFD软件建立旁通流场三维模型, 采用FLUENT软件中的标准k-ε模型进行数值模拟分析.分析结果表明:在产生旁通状态下, 高速流体通过旁路, 对管道内壁产生强剪切作用, 流过清管器后, 在下游形成涡流区.压力场分为上游高压区、清管器中压区、头部低压区和下游稳定区;旁路上和轴线上最大流体速度随间隙量的增加而减小, 流场压降及所受的驱动力随间隙量的增加而急剧减小.对比可知:两种类型的清管器旁路上最大流体速度、驱动力大小随间隙量的变化大致相同;在相同间隙量下直板式清管器轴线上的流体速度更大, 且旁路上的流体对管道内壁产生的剪切作用也更强.研究结果可为清管器在发生旁通状态下的通过安全性提供参考.%To understand the flow field distribution between the pig and the inner wall of the pipeline with bypass, and to provide a basis for improving the efficiency and safety of the pigging, the three-dimensional model of the bypass flow field is established by using ICEM CFD software, and is numerical simulated using standard k-εmodel in the FLUENT software. The analysis results show that with the bypass, the high-velocity fluid passes through the bypass and produces strong shearing action on the inner wall of the pipeline. Fluid flow through the pig produces a downstream vortex zone. The pressure field is divided into an upstream high pressure zone, a middle pressure zone at pig, a low pressure zone at the pig head, and a downstream stable zone. The maximum fluid velocity on the bypass and on the axis decreases with the increase of the clearance. The flow field pressure drop and the driving force decrease sharply with the increase of the clearance. The comparison shows that the maximum fluid velocity and the driving force of the two types of pig bypass are almost the same under the variation of clearance. Given the same amount of clearance, the fluid velocity on the axis of the straight plate-type pig is larger, and the fluid on the bypass produces stronger shearing effect on the inner wall of the pipeline. The study can provide references for the passing safety of the pipeline pig in the bypass state.