盲通管与直弯管的内壁液固双相流冲蚀数值模拟初探

A Preliminary Study on the Numerical Simulation of Liquid-Solid Two-Phase Erosion in Inner Wall of Blind Pipe and Straight-Bend Pipe

针对管道在流体流向急剧改变处受到的冲刷腐蚀问题,采用离散相DPM(Discrete Phase Model)模型,利用FLUENT软件对盲通管和直弯管进行分析仿真。通过改变入口速度、质量流量、固体颗粒大小、直弯管弯曲半径及盲通管的不同堵头长度和管径来探究每个因素对冲蚀速率的影响。结果表明:在其他条件相同情况下,盲通管和直弯管的最大冲蚀率随入口速度的增长呈现指数上升的趋势;随着固相颗粒直径增加,直弯管的最大冲蚀率呈线性增加,盲通管最大冲蚀率在颗粒直径为250~400μm呈平缓趋势,在小于250μm和大于400μm的范围内线性增长;随着直弯管弯曲半径的增大,直弯管的最大冲蚀率线性减小;通过改变盲通管的堵头长度发现盲通管堵头的长度变化不会对冲蚀率的大小产生明显影响,但盲通管的冲蚀速率会随着盲通管管径变大而减小,冲蚀区域随着管径的变大而减小且位置逐渐向管道上端移动。数值模拟的研究结果可为优化管道铺设提供相应的理论依据。

Aiming at the problem of erosion and corrosion of pipeline at the place where the flow direction of fluid changed sharply,DPM(Discrete Phase Model)was adopted and FLUENT software was used to analyze and simulate the impact of each factor on erosion rate by changing the inlet velocity,mass flow rate,particle diameter,bending curvature of elbow and different length and diameter of plug of blind-pass pipe.Results showed that under the same conditions,the maximum erosion rate of blind-pass pipe and straight-bend pipe increased exponentially with the increase of inlet velocity.With the increase of particle diameter,the maximum erosion rate of straight-bend pipe increased linearly,and the maximum erosion rate of blind-pass pipe showed a gentle trend in the range of particle diameter 250-400μm,and within the range of less than 250μm and more than 400μm the maximum erosion rate increased linearly.The maximum erosion rate of straight elbow decreased linearly with the increase of bending radius of straight elbow.By changing the length and diameter of blind-pass pipe plug,it was found that the change of the length of blind pipe plug did not have a significant impact on the erosion rate,but the erosion rate of blind pipe would decrease with the increase of blind pipe diameter,and the erosion area would decrease with the increase of pipe diameter.Moreover,the position moved gradually towards the upper end of the pipe.The research results provided a theoretical basis for optimizing pipeline laying.