输气管道中气油水和水合物的瞬态流动特性数值研究

对输气管道中气油水以及水合物的流动特性进行了四相四组分的数值计算研究。应用了相行为模型以及水合物相平衡模型对多组分的混合流动热力性质和水力特性进行研究。提出了相关的控制方程,并对流体与管壁之间的质量、动量以及热传递物理现象进行了描述。应用交错网格技术和有限差分法对控制方程进行求解,对边界条件和相的消失以及出现做出了很好地描述。用前人的调查结果对本文的模型进行了验证。应用此模型对管道中的流体流动特性进行了数值模拟,并通过分析所得结果对水合物的形成位置或潜在的形成位置进行了预测;通过对油气水以及水合物的水力流动特性进行分析,给出了输气过程中防止水合物的形成的方案。

Numerical Simulation on Transient Flow of Oil,Gas,Water and Natural Gas Hydrate in Gas Pipelines

Numerical simulation on flow characteristics of four-phase four-component of gas,oil,water and natural gas hydrate in a gas pipeline was carried out.The phase behavior model and hydrate phase equilibrium model were used to study thermodynamic and hydrodynamic properties of the multicomponent mixture.The related control equations were formulated for describing the physical phenomena of mass,momentum and heat transfers between the fluids and the wall.The equations were solved by utilizing the implicit finite difference method and the staggered-grid system,the boundary conditions and phase appearance or disappearance were properly described.The developed pipeline simulator was validated with the field data presented by previous investigation.The model was also applied to simulate a multi-component,four-phase flow system in order to examine the transient flow characteristics in pipeline.The location and potential location of hydrate formation in the pipeline were studied by analyzing the flow characteristics.As a result,it was found that a pipeline system flowing gas,oil water and hydrate could be optimized by systematically investigating the hydrodynamic variables for preventing hydrate formation.