聚长链α-烯烃减阻性能的影响因素研究

STUDY ON THE INFLUENCING FACTORS FOR DRAG-REDUCING PERFORMANCE OF POLY(LONG CHAIN α-OLEFIN)

利用室内环道评价装置考察聚长链α-烯烃减阻剂的溶解时间、雷诺数、加剂浓度、黏均相对分子质量和高聚物的抗剪切能力对减阻性能的影响。结果表明:聚合物的减阻率随溶解时间的延长而增大,达到一定值后趋于稳定;聚合物的凝聚状态以及颗粒的分散程度对减阻剂的溶解能力影响较大;加剂浓度在15mg/L时减阻率达到最大值,加剂浓度与减阻率的关系基本符合Virk经验公式;存在最佳雷诺数,雷诺数大于或小于最佳雷诺数时,减阻能力减弱,直至无效;在一定的相对分子质量范围内,黏均相对分子质量与减阻率呈线性关系,相对分子质量越大,减阻率越好;聚合物经过齿轮泵剪切后会使减阻率急剧下降,经过管壁的初次剪切也会使减阻率下降40%左右。

The drag reduction（DR） performance of poly（long chainα-olefin） was studied by an indoor loop evaluation device,including the effects of polymer dissolution time,Reynolds number,additive concentration,viscosity-average molecular weight and anti-shear behavior of polymer.Test results show that DR rate of polymer increases with the increase of polymer dissolution time till reach a stabilized value.The condensed state of polymer and the dispersion of particles have a significant effect on the dissolving capacity of polymer.Maximum DR rate is obtained at an additive concentration of 15 mg/L,and the relationship of additive concentration and DR rate is in accordance with Virk empirical equation basically.There is an optimal Reynolds number for obtaining maximum DR rate,below or beyond that value the DR performance will degrade till invalid.A linear relationship exists between the viscosity-average molecular weight and DR rate,the DR rate increases with the increase of molecular weight in a certain range.The DR rate of polymer sheared by gear pump drops significantly,and even an initial wall shear will cause a 40% reduction in DR rate.