煤浆浓度对油煤浆流变特性和表观黏度的影响

煤浆质量分数是影响油煤浆流变特性的主要因素之一。文中研究了煤浆质量分数对内蒙古胜利褐煤与液化起始溶剂和循环溶剂配制成的油煤浆的流变特性和表观黏度的影响。采用NXS-11A型旋转黏度计测量煤浆体系在30～70℃时在不同剪切速率下的剪切应力和表观黏度,绘制煤浆体系流变曲线和黏度曲线,分析了流变和黏度特性。结果表明:在实验条件下胜利褐煤起始溶剂油煤浆和循环溶剂油煤浆都符合宾汉流体的特征;油煤浆体系的塑性黏度、屈服应力和表观黏度都随煤浆质量分数的增大而增大,煤浆的表观黏度与煤浆质量分数之间呈指数增长型关系,当煤浆质量分数超过一定数值范围后,煤浆体系的表观黏度会急剧上升。

Influence of concentration on rheological properties and apparent viscosity of coal-oil mixtures

The concentration of coal-oil mixtures(COM) is one of the main factors affecting its rheological properties.This paper seeks to investigate the rheological and viscosity properties of Shengli lignite COM confected by initial and recycled solvent.The investigation consists of measuring the shear stress and apparent viscosity of COM systems at different shear rate and 30-70 ℃ by using rotational viscosimeter of NXS-11A,plotting rheological curves and riscosity curves respectively,and analyzing its rheological and apparent properties.The results indicate that the systems of Shengli lignite COM prepared by initial and recycled solvent consist with the characteristics of non-Newtonian Bingham fluid.The plastic viscosity,yield stress,and apparent viscosity increase with increasing coal concentration.The apparent viscosity correlates to the coal concentration exponentially and increases rapidly beyond a certain scale at high concentration.