摘要
为了进行零下温度时区域供冷系统的界面活性剂减阻设计，测量了-5℃时以质量分数为20％的甘醇不冻液为溶剂的界面活性剂溶液油醇基二羟乙基甲基氯化铵在二维通道内的减阻特性，同时用粒子成像测速仪对减阻流动的湍流特性进行了测量．实验发现：质量分数为5×10^-5～5×10^-4的低浓度油醇基二羟乙基甲基氯化铵界面活性剂溶液在一定的雷诺数范围内均呈现减阻特性，且其减阻特性与质量分数和温度呈复杂关系，最大减阻值可高达70％以上；在湍流液体中只需加入少量该界面活性剂即可大幅度减少液体输送的动力消耗．与单独的质量分数为20％的甘醇不冻液湍流流动相比，添加界面活性剂抑制了湍流速度脉动，使雷诺应力完全消失．
To design an efficient district cooling system with surfactant drag reduction at subzero temperature, the drag-reducing characteristics of Ethoquad O12/NaSal surfactant solution were measured with a 20% mass-fraction ethylene glycol aqueous solution （EG/W） as solvent in a 2-D channel at -5 ℃, and the turbulence features of the surfactant drag-reducing flow were also measured via particle image velocimetry （PIV） technique. It is found that the Ethoquad O12/ NaSal surfactant flowing with low mass fraction ranging from 5 × 10^- 5 to 5 × 10^-4 demonstrates the maximum drag reduction above 70%, and a complicated relationship of the drag-reducing characteristics with mass fraction and temperature. Added only small amount of this surfactant into the liquid turbulent flow, the pumping energy is reduced greatly during the liquid transportation. Compared with EG/W turbulent flow, the added surfactant suppresses the turbulent velocity and vortex fluctuations to eliminate Reynolds stress.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2006年第1期79-83,共5页
Journal of Xi'an Jiaotong University
基金
日本新能源产业技术综合研究与开发机构(NEDO)资助项目(2002EF001)
关键词
区域供冷
界面活性剂
减阻
湍流特性
district cooling system
surfactant
drag reduction
turbulence features
