段塞流对弯管瞬态冲击的三维CFD数值模拟研究

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振动与冲击 ›› 2022, Vol. 41 ›› Issue (23) : 322-329.

论文

康竞澜1，刘昉1，侯庆志1，何军龄2，林磊3

作者信息 +

3-D CFD numerical simulation of transient impact of slug flow on elbow

KANG Jinglan1, LIU fang1, HOU Qingzhi1, HE Junling2, LIN Lei3

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文章历史 +

摘要

在核电站和火电站管路系统中，来自上游的高压蒸汽可使管道中的凝结水团（段塞）加速运动，并在弯管、三通、阀门等非连续部位产生剧烈的冲击力，从而对管道造成严重破坏，影响电站的安全运行。针对管道中段塞运动的高维动力学特性，文章运用CFD对单个段塞在含弯头空管中的运动与冲击过程进行了三维数值模拟研究，并将数值模拟结果与文献中的物理实验结果进行了比较。结果表明：CFD模拟的冲击压力时程曲线及压力峰值都与实验结果具有良好的一致性。同时，基于理论分析，提出并详细论述了冲击过程中压力随时间变化的三种趋势，并通过数值模拟验证了其正确性；通过分析段塞长度的时程变化，得到了段塞的质量脱落率曲线；基于数值模拟得到的段塞瞬时冲击速度，验证了简化的冲击压力理论计算方法，发现理论计算值与实验以及数值模拟结果基本吻合。这证明了CFD数值模拟的准确性以及冲击压力简化计算方法的合理性，二者在实际工程应用中具有指导意义。
关键词：段塞流；弯管冲击；三维CFD数值模拟；气液两相流；VOF

Abstract

In the piping system of power plants, the high upstream steam pressure accelerates the condensed water mass in the pipeline and exerts violent impact on the obstacles such as elbow, tee and valve. This could cause serious damage to the obstacles and the pipeline, and affect the safe operation of the plant. Considering the high-dimensional characteristics of the liquid slug motion, in this paper, 3D CFD model is developed and applied to simulate the motion and impact processes of the liquid slug, and the simulations are compared with the experimental results in the literature. It is shown that both the time history curves and the peaks of the impact pressure are in good agreement with physical experiments. At the same time, based on theoretical analysis, three pressure trends are proposed and discussed during the impact process and their results are verified by numerical simulations. By analyzing the time history of the slug length, a mass loss rate curve is obtained. Moreover, based on the obtained instantaneous slug impact velocity, a simplified method for calculation of the impact pressure is verified. It is found that the theoretical calculations are in good agreement with both the experimental and numerical solutions. These results indicate that the CFD model and the proposed calculation method for the peak pressure are reliable tools for predicting the motion of the liquid slug in the pipeline and its impact on the elbow, both of which have the prospect in practical applications.
Key words: Slug flow; Elbow impact; 3D CFD numerical simulation; Gas-liquid two phase flow; VOF

导出引用

康竞澜1，刘昉1，侯庆志1，何军龄2，林磊3. 段塞流对弯管瞬态冲击的三维CFD数值模拟研究[J]. 振动与冲击, 2022, 41(23): 322-329

KANG Jinglan1, LIU fang1, HOU Qingzhi1, HE Junling2, LIN Lei3. 3-D CFD numerical simulation of transient impact of slug flow on elbow[J]. Journal of Vibration and Shock, 2022, 41(23): 322-329

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