逆流式双螺旋叶片气液固多相旋流分离特性

Gas-Liquid-Solid Cyclone Separation Characteristics of Reverse Flow Duplex Spiral Blade

针对海洋平台空间的局限性和天然气水合物开采特殊工况,设计了一种结构紧凑、分离效率较高、维护成本低的逆流式双螺旋叶片气液固多相旋流分离器,以期实现海上平台天然气、泥质粉砂和海水多相混流的高效分离。综合高含气、高流量、小粒径等因素耦合作用,建立气液固多相分离湍流数学模型,采用SIMPLE压力-速度耦合算法进行求解,揭示螺距、螺旋叶片头数和螺旋圈数等叶片结构参数对气液固多相旋流分离性能的影响规律;并依据气液固多相旋流分离双螺旋叶片的单因素优化结果,量化分析入口流速、含气体积分数、泥质粉砂粒径等生产参数对气液固多相旋流分离性能的影响程度。研究结果表明:当螺旋叶片的螺距为70 mm、螺旋头数为2且螺旋圈数为3时,逆流式双螺旋叶片气液固多相旋流分离性能最佳;增大入口流速可有效提高分离效率,入口流速达到3.0 m/s时,气、固两相分离效率分别提高至98.6%和83.2%;而含气体积分数由30%增至45%时,气相分离效率由99.4%降至96.5%,且气相出口含气体积分数由81.1%增至91.9%;泥质粉砂的粒径尺寸会影响分离效率,粒径尺寸为70 um时,分离效率可达93.4%。所得结论可为适用于天然气水合物开采的气液固多相分离器的设计和优化提供参考。

Aiming at the spatial limitation of offshore platform and special working conditions of gas hydrate exploitation,a reverse flow duplex spiral blade gas-liquid-solid cyclone separator with compact structure,high separation efficiency and low maintenance cost was designed,in the hope of realizing efficient separation of mixed flow of natural gas,muddy silt and seawater on offshore platforms.After having comprehensively considered the coupling effect of factors such as high gas content,high flow rate and small particle size,a mathematical model for gas-liquid-solid separation turbulence was built,and the SIMPLE pressure-velocity coupling algorithm was used to carry out solution,revealing the influence of blade structure parameters such as pitch,number of spiral blade heads and spiral turn on the gas-liquid-solid cyclone separation performance;then,based on the single factor optimization results of the gas-liquid-solid cyclone separation duplex spiral blade,the influence of production parameters such as inlet flow rate,gas volume fraction and muddy silt size on the gas-liquid-solid cyclone separation performance was quantitatively analyzed.The research results show that when the pitch of the spiral blades is 70 mm,the number of spiral heads is 2 and the spiral turn is 3,the gas-liquid-solid cyclone separation performance of the reverse flow duplex spiral blade is the best;increasing the inlet flow rate can effectively improve the separation efficiency;when the inlet flow rate reaches 3.0 m/s,the gas and solid separation efficiency is increased to 98.6% and 83.2% respectively;when the gas volume fraction increases from^(3)0% to 45%,the gas phase separation efficiency is decreased from 99.4% to 96.5%,and the gas volume fraction at gas phase outlet is increased from 81.1% to 91.9%;the particle size of muddy silt can affect the separation efficiency;when the particle size is 70 μm,the separation efficiency can reach 93.4%.The conclusions provide reference for the design and optimization of gas-liquid-solid separators suitable for gas hydrate exploitation.