半焦与不同制粉系统的适应性分析

Adaptability analysis for semi-coke in different mill systems

为了充分掌握半焦与不同制粉系统的适应性及其研磨特性,对中速磨煤机、中储式钢球磨煤机和直吹式双进双出钢球磨煤机上掺烧半焦前后的制粉系统性能进行测试,并对实际研磨出力与理论计算研磨出力进行比对,分析了煤质参数、煤粉细度、煤粉水分等指标对半焦研磨出力计算的影响。试验结果表明:无论对于哪种类型磨煤机,掺烧半焦后均有制粉系统出力下降和煤粉变粗的趋势,这主要与半焦的哈氏可磨性系数HGI较低密切相关;半焦在中速磨煤机上的实际出力低于理论计算出力,而部分半焦水分高也是导致钢球磨煤机实际研磨出力降低的主要原因;低水分半焦在钢球磨煤机上的实际研磨出力和理论计算结果接近,建议半焦应尽量在原煤HGI较低或者磨煤机研磨出力裕量较大的电厂掺烧,以保证锅炉燃烧的经济性和安全性。

In order to fully grasp the adaptability and grinding characteristics of semi-coke on different mill systems, the blending test of semi-coke on medium-speed mill and ball mill was carried out, and the theoretical calculation results and the actual grinding capacity of the mill were compared. The effects of coal quality parameters, coal powder fineness and coal powder moisture on the theoretical calculation of semi-coke＇s grinding capacity were analyzed. The results show that, for any type of the mill, the grinding capacity decreases and the coal powder fineness becomes coarse after grinding the semi-coke, this is mainly related to the low HGI value of the semi-coke itself. The actual grinding capacity of the semi-coke is lower ＇than the calculated output of medium-speed mill,while the high moisture is also the main reason leading to the results on the ball mill. The semi-coke with low moisture has a different conclusion,and the actual grinding capacity is basically equals to the calculated output on ball mill. It suggests that, to improve the safety and economy of the boiler, the semi-coke be blended in the power plant which burning coals with low HGI value or with a larger grinding capacity mill.