以扭带起旋的气固两相螺旋流流动与传热数值模拟

摘要

为了探讨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,利用ANSYS软件对天然气管道内的气固两相螺旋流动和传热进行了三维瞬态数值模拟.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、水合物颗粒沉降规律以及传热规律.模拟结果表明:螺旋流具有较强的携带能力,可以防止颗粒沉积,增强水合物颗粒之间的传热,避免形成水合物堵塞,保障管道安全;固体颗粒含量对携带能力有较大影响,当不含固体颗粒时,螺旋流流线稳定,衰减并不明显;当水合物颗粒体积分数达到8%左右,螺旋流的切向速度迅速衰减,衰减速率是无颗粒螺旋流的3倍.研究结果可为保障输气管道的安全输送提供理论指导.%To study the spiral suspension flow regime of natural gas hydrate particle transport system in gas pipeline, the three-dimensional transient simulation of gas-solid two-phase spiral flow and heat transfer in natural gas pipeline has been carried out using ANSYS software.The velocity field at different sections, the volume fraction distribution of hydrate particles, the hydrate particle sedimentation and the heat transfer in natural gas pipeline have been studied.The simulation results show that the spiral flow has a strong carrying capacity, which can prevent the sedimentation of particles, enhance the heat transfer between the hydrate particles, thus prevent the formation from hydrate block and ensure the safety of the pipeline.The content of solid particles has a great influence on the carrying capacity.Without the solid particles, the spiral flow line is stable and the attenuation is not obvious.Given the hydrate particle volume fraction of about 8%, the tangential velocity of the spiral flow is rapidly attenuated with the attenuated rate of three times than that of the spiral flow without particles.The study results could provide theoretical guidance for ensuring safe transportation by gas pipeline.