山区水平管流型数值模拟研究

Numerical Simulation of Flow Pattern in Horizontal Pipe in Mountainous Area

【目的】山区管道低洼处易积液形成腐蚀环境,而现场因高含硫无法打开管道,因此需要研究如何直观了解管道内部流型。【方法】利用计算流体动力学CFD,采用VOF模型耦合RNG k-ε模型研究不同速度、不同含液率下水平管道的流型分布、压力分布及含气率。【结果】结果发现:某气田流常见工况下管道内流型以层流为主,流速和含液率增加时,流型发生变化,混合速度Vmix=9.00 m/s时,体积分数Vol=0.3,出现分层流夹带(波浪、气泡),表现为过渡,当流速和含液率均增大时,分层流夹带(波浪、气泡)过渡为气泡流。【结论】研究发现,某山区常见工况下水平管含液率和流速存在主次竞争关系,流速增加会使气液界面扰动增大、携液能力增强,进而有助于避免积液腐蚀,研究成果可为山区水平管道流型研究提供参考。

[Purposes]Due to the corrosion environment caused by liquid accumulation in the low-lying area of the pipeline in mountainous areas,the pipeline cannot be opened due to high sulfur content.Therefore,it is necessary to study how to intuitively understand the internal flow pattern of the pipeline.[Methods]Therefore,this paper uses CFD(VOF and RNG k-ε)to explore the flow pattern distribution,pressure distribution,gas content and other processes of horizontal pipeline with variable speed and vari⁃able liquid content.[Findings]The results showed that:under common working conditions of a certain gas field flow,the flow pattern in the pipeline is mainly laminar flow.When the flow velocity and liquid content increase,the flow pattern changes.When Vmix=9.00 m/s,Vol=0.3,stratified flow entraining(wave and bubbles)appears,showing a transition state.When the flow rate and liquid content continue to in⁃crease,the certain(wave,bubble)of stratified flow becomes a bubble flow.[Conclusions]It is found that there is a primary and secondary competition between the liquid content and the flow rate of the horizon⁃tal pipe under common working conditions in a mountainous area.The increase of the flow rate will in⁃crease the disturbance of the gas-liquid interface and enhance the liquid carrying capacity,which will help to avoid the corrosion of the liquid accumulation.The research results can provide a reference for the study of the flow pattern of horizontal pipelines in mountainous areas.