Rahman Saifur, Khan Rehan, Niazi Usama Muhammad, Legutko Stanislaw, Khan Muhammad Ali, Ahmed Bilal Anjum, Petrů Jana, Hajnyš Jiří, Irfan Muhammad
Electrical Engineering Department, College of Engineering, Najran University, Najran 61441, Saudi Arabia.
Department of Mechanical Engineering, College of Electrical and Mechanical Engineering, National University of Sciences and Technology, Islamabad 44000, Pakistan.
Materials (Basel). 2022 Aug 12;15(16):5558. doi: 10.3390/ma15165558.
Erosion of the elbow due to non-Newtonian viscous slurry flows is often observed in hydrocarbon transportation pipelines. This paper intends to study the erosion behavior of double offset U-bends and 180° U-bends for two-phase (liquid-sand) flow. A numerical simulation was conducted using the Discrete Phase Model (DPM) on carbon steel pipe bends with a 40 mm diameter and an R/D ratio of 1.5. The validity of the erosion model has been established by comparing it with the results quantified in the literature by experiment. While the maximum erosive wear rates of all evaluated cases were found to be quite different, the maximum erosion locations have been identified between 150° and 180° downstream at the outer curvature. It was seen that with the increase in disperse phase diameter, the erosive wear rate and impact area increased. Moreover, with the change of configuration from a 180° U-bend to a double offset U-bend, the influence of turbulence on the transit of the disperse phase decreases as the flow approaches downstream and results in less erosive wear in a double offset U-bend. Furthermore, the simulation results manifest that the erosive wear increases with an increase in flow velocity, and the erosion rate of the double offset U-bend was nearly 8.58 times less than the 180° U-bend for a carrier fluid velocity of 2 m/s and 1.82 times less for 4 m/s carrier fluid velocity. The erosion rate of the double offset U-bend was reduced by 120% compared to the 180° U-bend for 6 m/s in liquid-solid flow.
在油气输送管道中，常可见到非牛顿粘性浆液流动导致的肘部侵蚀现象。本文旨在研究双偏置U型弯管和180°U型弯管在两相（液-砂）流中的侵蚀行为。采用离散相模型（DPM）对直径为40 mm、R/D比为1.5的碳钢弯管进行了数值模拟。通过与文献中实验量化结果对比，验证了侵蚀模型的有效性。虽然所有评估案例的最大侵蚀磨损率差异较大，但最大侵蚀位置均位于外曲率下游150°至180°之间。研究发现，随着分散相直径的增大，侵蚀磨损率和冲击面积均增大。此外，随着构型从180°U型弯管变为双偏置U型弯管，随着流体向下游流动，湍流对分散相传输的影响减小，导致双偏置U型弯管的侵蚀磨损更小。此外，模拟结果表明，侵蚀磨损随流速增加而增大，对于2 m/s的载液流速，双偏置U型弯管的侵蚀率比180°U型弯管低近8.58倍；对于4 m/s的载液流速，低1.82倍。在液固流中，当流速为6 m/s时，双偏置U型弯管的侵蚀率比180°U型弯管降低了120%。
