煤热解中移动床床层阻力的试验研究

Experimental study on bed resistance of moving bed in pyrolysis of coal

为进一步提高计算移动床床层压降的准确性,文章通过分别测试原煤的视密度和堆积密度,计算出固定床的空隙率,在固定床试验的基础上结合Ergun方程确定物料球形度,并在此基础上进一步利用移动床试验测试移动床中床层颗粒表观速度及表观气速与空隙率的关系,最后对其结果进行非线性拟合。结果表明:煤料球形度约为0. 709 7,床层颗粒表观速度与表观气速对空隙率有一定的影响,但表观气速对空隙率影响很小,忽略其影响,对床层颗粒表观速度与空隙率进行拟合,得到拟合公式为ε=0. 019 3 ln u+0. 392 6。利用该拟合公式并结合Ergun方程计算的压降与工业实际运行数据相比,数据误差约为10%。

In order to further improve the accuracy of calculating the pressure drop of the moving bed,the void fraction of the fixed bed was calculated by measuring the apparent density and bulk density of the raw coal separately.Based on the fixed bed test,the sphericity of the material was determined by Ergun equation.On this basis,the relationship between apparent particle velocity and superficial gas velocity and void fraction in moving bed was further tested by moving bed test.Finally,the results were nonlinearly fitted.The results show that the sphericity of coal is about 0.709 7.The apparent velocity and superficial velocity have a certain influence on the porosity.However,the superficial gas velocity has little effect on the porosity.Ignoring the influence of the apparent velocity,apparent velocity and porosity were fitted,the fitting formula wasε=0.019 3 ln u+0.392 6.The pressure drop calculated by using the fitting formula and the Ergun equation is about 10%compared with the actual industrial operation data.