基于CFD的输气管道射流清管器喷嘴类型优选

Optimization of Jet Pig Nozzle Type for Gas Pipeline Based on CFD

天然气管输过程中粉尘等污垢易附着在管内壁,导致管输效率降低,影响生产运行。应用射流清管器射流吹扫作用可有效清除管内污垢,保障流动安全。为进一步评价射流清管器不同喷嘴类型的管内壁吹扫能力,以D273 mm×10 mm的天然气管道为例,基于计算流体力学基本原理,应用Fluent软件模拟不同类型喷嘴的射流流场。基于数值计算结果,分析了不同类型喷嘴射流流速及湍流动能在下游管道中的变化规律,分析结果表明:轴心喷嘴射流轴向速度较高,但管壁处吹扫速度很低,对管内壁几乎无吹扫作用;支状喷嘴可对管道内壁进行有效冲刷,但仅能形成局部的射流吹扫;环状喷嘴对管内壁均匀吹扫且吹扫范围最大,相较于支状喷嘴,其速度分布更均匀,对管内壁附着污垢的吹扫及粉尘携带效果最佳,并有利于药剂的均匀敷设。研究结果可为射流清管器的结构优化设计提供理论依据。

In the process of natural gas pipeline transportation,dust and other dirt are easy to adhere to the inner wall of the pipe,which reduces the efficiency of pipeline transmission and affects operation.The jet cleaning effect of the jet pig can effectively remove the dirt in the pipe and ensure the safety of flow.To further evaluate the cleaning ability of different nozzle types of jet pigs,a natural gas pipeline of D273 mm×10 mm is taken for study.Based on the basic principles of computational fluid dynamics,Fluent software is used to simulate the jet flow field of different types of nozzles.Based on the results of numerical calculations,the changes in jet flow velocity and turbulent energy of different types of nozzles in downstream pipelines are analyzed.The analysis results show that:the axial nozzle jet has a higher axial velocity,but the sweeping speed at the pipe wall is very low,which has almost no cleaning effect.The branch nozzle can effectively flush the inner wall of the pipe,but it can only form a partial jet cleaning.The annular nozzle sweeps the inner wall of the pipe uniformly and has the largest sweep range,which has a more uniform speed distribution compared with the branch nozzle.Therefore,the annular nozzle has the best cleaning effect for the dirt attached to the inner wall and dust carrying performance,and is conducive to the uniform laying of the agents.The research results can provide a theoretical basis for the structural optimization design of the jet pig.