固体颗粒水力输送中CTAB的减阻实验研究

发布时间：2018-04-03 21:30

本文选题：表面活性剂　切入点：减阻　出处：《湖南工业大学》2015年硕士论文

【摘要】：在流体中加入微量的高分子聚合物或表面活性剂可显著降低湍流流体的摩擦阻力,该流体被称为添加剂减阻流体。由于表面活性剂在抗机械降解性上优于高分子聚合物,因此更适用于闭式循环系统和长距离管道运输系统。相对于十六烷基三甲基溴化铵表面活性剂(cetyltrimetyl Ammonium bromide,CTAB)水溶液,至今国内对CTAB在固体颗粒水力输送中的减阻研究还从未有过。为探讨表面活性剂在固体颗粒水力输送中的减阻特性,通过敞开式半循环水流系统分析了固液两相流的水力坡度与固体质量浓度及颗粒粒径之间的关系,并使用直径为10mm的不锈钢圆管研究了不同CTAB浓度在水溶液和固体颗粒水力输送中的减阻特性。在敞开式半循环水流系统中测量了不同固体颗粒浓度和粒径下固液两相流的水力坡度的变化规律。实验结果发现:在相同的粒径下,固液两相流的水力坡度随着溶液中的固体质量浓度增加而增大。在相同的固体质量浓度下,固液两相流的水力坡度随着溶液中颗粒粒径增大而减小。CTAB减阻实验结果表明:固体质量浓度和粒径恒定的情况下,CTAB在固体颗粒水力输送中减阻的条件是CTAB浓度超过某个临界值。在相同的固体质量浓度和粒径下,固液两相流的水力坡度随着CTAB浓度的增大而减小;在CTAB浓度一定的情况下,固体颗粒水力输送中CTAB的减阻能力随着固体质量浓度的增加而显著降低,且随着粒径的减小而减弱。由固体质量浓度和粒径引起流场中剪切应力的变化可认为是造成CTAB减阻能力发生改变的主要原因。CTAB减阻技术应用于固体颗粒水力输送中可减少固液两相流系统中泵能的消耗。这对长距离固体颗粒水力输送具有重要的意义。
[Abstract]:The friction resistance of turbulent fluid can be significantly reduced by adding a small amount of polymer or surfactant to the fluid, which is called additive drag reducing fluid.Surfactant is more suitable for closed circulation system and long distance pipeline transportation system because of its better mechanical degradation resistance than polymer.Compared with cetyltrimethylammonium bromide (cetyltrimetyl Ammonium bromideCTAB) aqueous solution, the drag reduction of CTAB in hydraulic transport of solid particles has never been studied in China.In order to study the drag reduction characteristics of surfactants in hydraulic transport of solid particles, the relationship between hydraulic gradient of solid-liquid two-phase flow and solid mass concentration and particle size was analyzed by open-loop flow system.The drag reduction characteristics of stainless steel pipe with diameter of 10mm in aqueous solution and solid particle hydraulic transport were studied with different CTAB concentration.The variation of hydraulic gradient of solid-liquid two-phase flow with different particle concentration and particle size was measured in an open semi-circulating flow system.The experimental results show that the hydraulic gradient of solid-liquid two-phase flow increases with the increase of solid mass concentration at the same particle size.At the same solid mass concentration,The hydraulic gradient of solid-liquid two-phase flow decreases with the increase of particle size in the solution. The results of drag reduction experiment show that the condition of reducing drag of CTAB in hydraulic transport of solid particles is that the concentration of CTAB exceeds a critical value under the condition of constant solid mass concentration and particle size.Under the same solid mass concentration and particle size, the hydraulic gradient of solid-liquid two-phase flow decreases with the increase of CTAB concentration, and when the CTAB concentration is constant, the hydraulic gradient of solid-liquid two-phase flow decreases with the increase of CTAB concentration.The drag reduction ability of CTAB decreases with the increase of solid mass concentration and decreases with the decrease of particle size in hydraulic conveying of solid particles.The change of shear stress in flow field caused by solid mass concentration and particle size can be considered as the main reason for the change of drag reduction capacity of CTAB. The application of drag reduction technology in solid particle hydraulic transportation can reduce the consumption of pump energy in solid-liquid two-phase flow system.This is of great significance to the long distance hydraulic transport of solid particles.
【学位授予单位】：湖南工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ022.3

【共引文献】