【摘要】 针对含砂天然气对长输管道弯头处的冲蚀现象,以90°弯管为例,运用单向耦合冲蚀模型及控制变量法分析颗粒质量流率、流体进口流速、颗粒粒径及重力场对弯管的冲蚀作用,结果表明:在非重力场中,弯管的冲蚀区域主要集中在拐角大弧面区,且呈椭圆形分布;随颗粒质量流率的增加,最大冲蚀速率拟合曲线呈线性正相关;随流体进口流速的增加,最大冲蚀速率拟合曲线呈非线性指数相关,指数系数为0.305 8;随颗粒粒径的增加,最大冲蚀速率呈先减小后增大再减小的变化趋势;相同条件下,在重力场中弯管的冲蚀集中区域与非重力场相同,但最大冲蚀速率明显增大,且冲蚀区域发生变化;当重力为沿出口法向正向时,冲蚀区域由椭圆形变为圆形,并伴有二次冲蚀集中现象,当重力为沿出口法向反向时,冲蚀区域由椭圆形变为三角锥形。更多还原

【Abstract】 The erosion at the elbow in a long-distance transportation pipeline for sand-containing natural gas has been investigated. Taking a 90° elbow as an example, the DPM one-way coupling erosion model and the controlled variable method were used to analyze the mass flow rate, fluid inlet flow rate, particle size and compare the erosion of the curved tube in gravity and non-gravity fields. The results show that in a non-gravity field, the erosion area of the elbow is mainly concentrated in the large arc area of the corner, and is elliptical. The maximum erosion rate fitting curve increases linearly with increasing mass flow rate, whilst it is nonlinearly exponentially correlated with increasing fluid inlet flow rate, with an exponential coefficient of 0.305 8. With increasing particle size, the maximum erosion rate initially decreases, then increases and finally decreases again. In a gravity field under the same conditions, the erosion area of the elbow is the same as in the non-gravity field, but the maximum erosion rate is significantly increased. When the gravity is positive along the exit normal, the erosion region changes from elliptical to circular with secondary erosion concentration, whereas when gravity is reversed along the exit normal, the erosion region changes from elliptical to trigonal pyramidal.更多还原