大跨越管道油气混输压力波速及响应特性研究

Research of Pressure Wave Velocity and Response Time for Oil-Gas Mixing Transportation in Large Span Pipelines

基于双流体模型,利用小扰动理论,提出了油气混输大跨越管道压力波速模型.利用计算机编程对其求解,通过大跨越管道油气混输实例,得到了以下结论:压力波速的变化受气相影响较大,即使少量气体也能在较大程度上影响压力波速,随混输气量增大,压力波速减小,压力响应时间延长;混输低点气体所承受的压力较混输高点大,从而低点处气相压缩系数小,混输低点较混输高点压力波速增大,压力响应时间相应缩短;在输运管道低点处,气体受到极大压缩,压力波速的变化不明显,几乎收敛于恒定值,在混输管道高点处压力波速变化剧烈.

Based on the 2-fluid model and the theory of small perturbation,the pressure wave velocity model was put forward for the oil-gas mixing transportation in large span pipelines,and the computer program to solve this model was built.The conclusions based on a practical engineering example are as follow：in the process of multiphase mixing large span transportation,the change of pressure wave velocity is more influenced by the gas phase,even a small amount of mixed gas can affect the pressure wave velocity dramatically.With the increase of mixed gas,the pressure wave velocity decreases and the pressure response time extends.The pressure at the low point is higher than at the high point,so the gas compressibility factor at the low point is smaller than at the high point and the pressure wave velocity at the low point is bigger,meanwhile,the pressure response time at the low point is shorter.Moreover,at the low point of mixed transportation the mixed gas is compressed tremendously,so the pressure wave velocity there changes little and almost remains at a constant value;in contrast,the pressure wave velocity changes easily at the high point.