常压低温条件下油煤浆黏度变化的研究

STUDY ON VISCOSITY OF OIL-COAL SLURRY AT LOW-TEMPERATURE AND ATMOSPHERE

在煤直接液化过程中,油煤浆的黏度变化是工艺设计的重要参数之一.进行了常压低温条件下影响油煤浆黏度变化的实验研究,分析了溶剂、煤粒度、煤油比以及外力因素如剪切速率、温度和溶胀等条件对煤浆黏度的影响规律.实验结果表明:煤浆的黏度随溶剂黏度的增大而增大,随煤颗粒粒度增大而减小,随煤油比增大而升高.煤浆的表观黏度随剪切速率的增大而逐渐降低,表现出一定的剪切稀化性,煤颗粒在溶剂中发生溶胀,煤浆体系的黏度由于溶胀而增大.温度对浆体的黏度影响较大,黏度随温度升高而降低,通过对实验数据的数学回归,建立了一定温度范围内黏度随温度变化的定量关系式.

Viscosity of coal slurry is an important technological parameters during coal direct liquefaction. In this paper, some influencing factors for viscosity change of oil-coal slurry were studied at low-temperature and atmosphere,whlch includes solvent properties, granularity, and the ratio of coal to solvent, temperature, solvent swelling, and shear rate. The results show that viscosity of coal slurry increases with coal granularity decreasing and with solvent viscosity and the ratio of coal to solvent increasing, and coal swelling is one of the major （actors causing viscosity change during direct coal liquefaction. The results indicate that viscosity of coal slurry increases with coal swelling and decreases with shear rate increasing, and coal slurry represents shear thinning behavior. Apparent viscosity decreases with temperature increasing, and the relation equation of viscosity-temperature was established by analysis and regression.