输气管道水合物颗粒螺旋流动数值模拟

摘要

为了对输气管道中天然气水合物颗粒输送体系的螺旋悬浮流动规律做出进一步研究,利用ICEM软件对天然气管道内的气固两相螺旋流进行了三维瞬态数值模拟与仿真.研究了天然气管道内不同横截面的速度场、水合物颗粒体积分数分布规律以及水合物颗粒沉降规律.模拟结果表明:当水合物颗粒体积分数达到8%左右时,螺旋流的切向速度衰减迅速,对水合物颗粒的携带能力也急剧下降,衰减速率是无颗粒螺旋流的几倍;螺旋强度较大时,流体速度曲线表现出"双峰"特点,螺旋强度较小时,流体速度曲线表现出"抛物线"特点;流体速度是影响颗粒运动的主要因素,叶轮角度是次要因素,流体携带能力与颗粒体积分数及颗粒粒径成反比.所得结论可为输气管道的安全输送提供理论指导.%To further study the law of spiral suspension flow of the gas hydrate particle transport system in gas pipeline,the three-dimensional transient numerical simulation and simulation of the gas-solid two-phase spiral flow in the natural gas pipeline were carried out by ICEM.The velocity field,the distribution of gas hydrate particle volume fraction and the hydrate particle settling law at different cross sections of natural gas pipeline have been studied.The simulation results show that,when the volume fraction of gas hydrate particles reaches about 8%,the tangential velocity of the spiral flow declines rapidly and the carrying capacity of the gas hydrate particles also decreases sharply.The decay rate is several times of that of the spiral flow without particles.The fluid velocity curve shows a"double peak"and a"parabola"characteristicre spectively when the spiral strength is strong and weak.The velocity of the fluid is the main factor and the impeller angle is the secondary factor in affecting the particle motion.The fluid carrying capacity is inversely proportional to the particle volume fraction and particle size.The conclusions could provide theoretical guidance for the safe operation of gas pipeline.