摘要
山地长输气管道常穿越河流,河床冲刷下切会导致穿河管道裸露、悬空,管道的受力状态及载荷分布也相应改变,为了分析这种情况,以某一因河床冲刷下切而裸露出来的穿河输气管道为例,采用Fluent软件分别模拟在进水口来流洪水水面高程与管道等高、超出管道1 m、2 m时洪水在管道上游16 m、下游15m的流动,计算了输气管道外表面的压强分布,并对整个管道进行受力分析。研究结果表明:穿河管道弯矩最大的部位为管道与岸坡接触的部位;弯矩垂直分量约为水平分量的2倍,竖向水荷载是威胁管道安全的主要因素;管壁上的最大最小应力均大于钢管的屈服强度;采用试算法确定工程中采用的L485型管道抵抗洪水荷载所需的最小壁厚为24 mm。这些成果可为山地穿河管道的设计和维护提供参考。
Long mountain gas pipelines often cross rivers,and the riverbed is scoured and cut down,which lead to the pipeline across the river exposed and suspended,and the stress state and load distribution of the pipeline are also changed accordingly. In order to analyze this situation,taking a river-crossing gas pipeline exposed due to riverbed scouring and cutting as an example,Fluent software is used to simulate the flow of flood water in the upstream 16 m and downstream 15 m when the flood water surface elevation at the water inlet is equal to the height of the pipeline and exceeds 1 m and 2 m of the pipeline, the pressure distribution on the outer surface of the gas pipeline is calculated, and the stress analysis on the whole pipeline is carried out. The results show that the blending moment of the rivercrossing pipeline is greatest in the part where the pipeline and the bank come into contact. The vertical component of the bending moment is about twice that of the horizontal component, and the vertical water load is the main factor that threatens the pipeline safety. The maximum stress and minimum stress on the wall are both greater than the yield strength of the steel tube. The trial algorithm is used to determine that the minimum wall thickness required for the flood load resistance of L485 pipeline used in the project is 24 mm. These results can provide a reference for the design and maintenance of the pipeline crossing river in mountainous areas.
作者
王磊
赵志超
蔡强
WANG Lei;ZHAO Zhichao;CAI Qiang(Chongqing Natural Gas Pipeline Co.,Ltd.)
出处
《油气田地面工程》
2020年第5期47-52,72,共7页
Oil-Gas Field Surface Engineering
关键词
穿河管道
Fluent软件
洪水荷载
数值模拟
管道应力
pipeline crossing river
Fluent software
flood load
numerical simulation
pipeline stress
