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过程工程学报 ›› 2019, Vol. 19 ›› Issue (1): 83-90.DOI: 10.12034/j.issn.1009-606X.218158

• 流动与传递 • 上一篇    下一篇

90°圆截面弯管内稠油流动特性分析

顾效源,潘福奎,汪文杰,张黎明*   

  1. 中国石油大学(华东)石油工程学院,山东 青岛 266580
  • 收稿日期:2018-03-22 修回日期:2018-05-29 出版日期:2019-02-22 发布日期:2019-02-12
  • 通讯作者: 张黎明

Numerical simulation on flow characteristics of heavy oil through circular-sectioned 90° bends

Xiaoyuan GU, Fukui PAN, Wenjie WANG, Liming ZHANG*   

  1. School of Petroleum Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, China
  • Received:2018-03-22 Revised:2018-05-29 Online:2019-02-22 Published:2019-02-12
  • Contact: Ming LiZHANG

摘要: 采用计算流体力学三维层流模型模拟,研究了温度50~75℃、雷诺数Re=300~800、弯管内径D=50.7~131.7 mm、弯径比B=0.75~3.0条件下稠油在90°弯管内的阻力特性,分析了弯管局域阻力系数波动的机理。结果表明,随温度升高、入口雷诺数下降、弯管直径增加,局域阻力系数提高;在弯管0~15°范围内阻力下降,原因是弯管内形成双纵向涡,75°到弯管后0.5D范围内阻力下降,原因是弯管内形成4个纵向涡;弯管的弯径比对局域流动阻力影响很大,B=0.75时相邻截面最大落差达B=3.0时的28.35倍,但管道进出口阻力仅为1.68倍,原因是弯径比B≤1.0时,弯管后1.0D范围内侧形成了局域低压区,对应位置出现流向涡旋,同时弯管后0.5D截面稠油剪切速率达到峰值。

关键词: 90°圆截面弯管, 稠油, 流体力学性能, 涡旋

Abstract: The flow of heavy oil in circular-sectioned 90° bends was investigated. The local hydrodynamic performance was affected by heavy oil flow parameters and structure parameters of bend. Computational fluid dynamics (CFD) was used to numerical calculate the three-dimensional laminar flow for circular-sectioned 90° bends, and heavy oil was used as the research medium. The resistance of heavy oil was exported at temperature 50~70℃, Reynolds number 300~800, the inner diameter of pipe D=50.7~131.7 mm, bending ratio B=0.75~3.0. The mechanism of the local drag coefficient in bend was analyzed. The results showed that the local drag coefficient increased with the increase of temperature, the inlet Reynolds number decreased and D increased. The resistance decreased in the range of 0~15° in the bend because of the formation of double longitudinal vortices, and the scope of resistance decreased from 75° in the bend to 0.5D behind the bend because of the formation of four longitudinal vortex bend. The effect of local flow resistance was greater by bending ratio than the other. The maximum value of the local drag coefficient when B=0.75 was 28.35 times of that of B=3.0, however, the pipeline resistance between inlet and outlet was only 1.68 times. The reason was that there was a local low pressure region at 1.0D behind the bend when the bending ratio B≤1.0. Meanwhile, there was a flow vortex, and the peak of shear rate located 0.5D behind the bend. The conclusions can provide technical support, and the theoretical study about the secondary flow characteristics of heavy oil in the pipe can provide reference data for the design of heavy oil pipeline. The initial state parameters of heavy oil can be predicted in the engineering practice.

Key words: circular-sectioned 90°, bend, heavy oil, flow characteristics, vortex