【作者】 苏文涛；

【导师】 李凤臣；

【作者基本信息】 哈尔滨工业大学 ， 流体机械及工程， 2009， 硕士

【摘要】 添加剂减阻技术是指在液体湍流流动中加入微量的添加剂,从而使流动所受摩擦阻力显著降低的流体输送技术。该技术可以用来减小系统的能耗、增加流速并减小系统中的管径等。通过对不同种类减阻剂的特性进行综合分析比较,最终选定两性离子表面活性剂十八烷基二甲基氧化胺(C₂₀H₄₃NO)水溶液进行湍流减阻特性实验研究。首先对C₂₀H₄₃NO水溶液在循环系统中的减阻特性进行了实验研究。主要从C₂₀H₄₃NO水溶液减阻的最佳浓度、温度效应及抗剪切特性等方面进行实验研究。为了深入研究C₂₀H₄₃NO水溶液在实际供暖系统中的特性,在实验室模拟了C₂₀H₄₃NO水溶液在实际管路不同管径情况下的减阻实验。分别测试了这种溶液在DN50、DN100和DN150三种管径下的减阻特性;并且研究温度60℃时2500ppm C₂₀H₄₃NO水溶液在水泵连续运行工况下的减阻率随时间变化特性。最后,对添加剂减阻效应在集中供暖系统应用中进行了整体分析,提出了在实际应用过程中出现的一些问题,如:表面活性剂减阻时效性差、减阻不稳定,减阻剂本身存在一定程度腐蚀性等。针对以上存在的问题,通过浸泡的方式对C₂₀H₄₃NO水溶液的腐蚀性进行了实验研究。结果表明:与水和CTAC水溶液相比,C₂₀H₄₃NO是一种对铁基金属管道腐蚀性很小的表面活性剂。更多还原

【Abstract】 Additive drag-reduction is a technique in liquid transportation area that adding a minute amount of additives in turbulent flow of liquid can result in a significant reduction of frictional resistance encountered in the flow. Its application can decrease the energy consumption of flow systems, increase the flow velocity and reduce the diameter of tubes in the system. By a comprehensive characteristic comparison of different types of drag-reducing additives, the aqueous solution of zwitterionic surfactants (C₂₀H₄₃NO) is choosed to investigate the experimental properties of turbulent drag reduction.Firstly, an experimental study of drag-reducing characteristics of C₂₀H₄₃NO aqueous solution in a circulation system is conducted, including the optimal concentration of surfactant, temperature effect and anti-shear properties. In order to study the drag-reducing characteristics of C₂₀H₄₃NO aqueous solution in the practical heating system, the experiments with C₂₀H₄₃NO aqueous solution flow in different-inner-diameter pipelines are presented. Drag-reducing properties of this solution were investigated in the DN50, DN100 and DN150 pipelines, respectively. Meanwhile, the relationship of drag-reducing vs. time at temperature 60℃and concentration 2500ppm were researched, with the pump working all the time.Finally, the technique of additive drag-reduction applying in the district heating system is analyzed overall, meanwhile, some problems in the practical application are brought forward, such as: the poor time bound of surfactant, instabilities of drag-reducing effect and the inherent corrosion of additive itself. According to these problems, the corrosivity research of C₂₀H₄₃NO aqueous solution is also conducted using immersion method. The results show that: comparing with CTAC solution and water, C₂₀H₄₃NO is weakly corrosive for iron-based metallic pipe.更多还原