天然气水合物输送管道的压力损失规律

Pressure loss of conveying pipeline of natural gas hydrate

为了研究海底天然气水合物绞吸式开采水力输送系统中管径、流速、体积分数和颗粒粒径对输送系统压力损失的影响规律,确定各参数的合理选择范围;建立输送管道三维流场模型,采用控制变量的方法,运用计算流体力学理论和Fluent仿真软件对输送管道内固液两相流场进行仿真分析。研究结果表明:输送系统压力损失梯度随管径的增大而减小;当管径增大到0.4 m时,继续增大管径对压力损失梯度影响越来越小;压力损失梯度随浆体流速的增大先减小后增大,存在1个最优流速,在2.5～4.0 m/s之间,且颗粒粒径和体积分数越大,对应的最优流速就越大,压力损失梯度随体积分数的增大呈线性增大;压力损失梯度随着颗粒粒径增大而增大,但增大幅度很小。

To study the influence law between pressure loss of conveyor system and parameters of hydraulic transmission system for cutter-suction mining in submarine natural gas hydrate exploitation,such as diameter,velocity,volume fraction and particle size,and to determine the reasonable selection of the parameters,the three-dimensional flow field model of pipeline was established,and the method of controlling variables,the computational fluid dynamics theory and Fluent simulation software were used for numerical analysis in the solid liquid two-phase flow field of the pipeline.The results show that the pressure loss gradient of the conveying system decreases with the increase of the pipe diameter,and when the diameter of the pipe increases to 0.4 m,the effect of increasing the pipe diameter on pressure loss gradient is smaller and smaller.The pressure loss gradient decreases first and then increases with the increase of the flow velocity of the slurry,and there is an optimal velocity,which is between 2.5 m/s and 4.0 m/s,and the larger the particle size and volume fraction,the greater the corresponding optimal velocity.The pressure loss gradient increases linearly with the increase of volume fraction.The pressure loss gradient increases with the increase of particle size,but the increase is small.