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    一种特殊的胶束减阻剂的减阻及其流变特性

    Drag reduction of a special micellar drag reducer and its rheological characteristics

    • 摘要: 为开发更经济的管输水技术和深入探究胶束减阻剂的减阻机理,实验测试了油烯基二羟乙基甲基氯化铵(Ethoquad O/12)稀薄水溶液的管流减阻和流变特性,反离子助剂为水杨酸钠(NaSal)。减阻测试表明,最大减阻率可达70 %的量级;抗剪切能力和抗老化能力均随助剂对主剂摩尔比的增加而增强,这有别于其它阳离子胶束减阻剂的减阻特性。剪切粘度测试揭示,具有减阻效果的Ethoquad O/12稀薄水溶液都是非常复杂的非牛顿流体,且随摩尔比加大,胶束结构开始编网的剪切速率增加。剪切应力松弛实验证实,由0.1秒量级的松弛时间表征的胶束聚合结构对这种胶束减阻剂的减阻必不可少,小摩尔比使减阻液具有较强粘弹性,大摩尔比使粘弹性减弱。这个特殊的减阻特性的揭示为管路输水技术开发将提供有力的技术支持,相应的粘弹特性对添加剂减阻机理的探究提供新的参考判据。

       

      Abstract: To develop more economical technology for pipeline water transport and to delve deeper into the drag reduction mechanism of micellar drag reducers, experiments have been conducted to examine the pipe flow drag reduction and rheological properties of dilute aqueous solutions of oleyl dihydroxyethyl methyl ammonium chloride (Ethoquad O/12), with sodium salicylate (NaSal) as the counterion additive. Drag reduction tests indicate that the maximum drag reduction rate can reach an order of magnitude of 70%. The shear resistance and anti-aging capability all increase as the molar ratio of the counterion to the drag reducer, a characteristic distinct from that of other cationic micellar drag reducers. Shear viscosity measurements reveal that the dilute aqueous solutions of Ethoquad O/12, which exhibit drag reduction effects, are highly complex non-Newtonian fluids. Moreover, as the molar ratio increases, the shear rate at which the micellar structure begins to form networks also increases. Shear stress relaxation experiments confirm that the micellar aggregate structure, characterized by a relaxation time on the order of 0.1 seconds, is indispensable for the drag reduction effect of this micellar drag reducer. A low molar ratio imparts strong viscoelasticity to the drag-reducing fluid, whereas a high molar ratio weakens its viscoelasticity. The elucidation of this unique drag reduction characteristic provides valuable technical support for the development of pipeline water transport technology, and the corresponding viscoelastic properties offer a new reference criterion for exploring the drag reduction mechanism of additives.

       

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