600MW机组配置旋转分离器的中速磨煤机煤粉细度调整试验

锅炉燃用煤粉越细，对煤的着火和燃尽越有利，煤粉细度直接影响飞灰和炉渣可燃物的含量。针对山西兴能电厂运行中存在的干渣机落红渣、渣温高、碎渣机常被卡停运等问题，进行了磨煤机煤粉细度调整试验，通过调整磨煤机分离器转速改变煤粉细度；保持炉膛出口氧量稳定，考察煤粉细度对飞灰和渣块可燃物含量及锅炉热效率的影响；为中速磨煤机旋转分离器提供调整依据。试验结果表明，将煤粉细度控制在17%左右，煤粉均匀性指数达到120，煤粉中粗颗粒大量减小，有利于煤粉燃尽。煤粉细度调整后该电厂锅炉渣温、渣量下降，提高了机组的安全性和经济性。

Adjustment Tests of Pulverized Coal Fineness for Medium Speed Mill with Rotary Separator in 600 MW Unit

The smaller pulverized coal fineness is better for the ignition and burnout of coal. And the fineness of pulverized coal directly influences the content of combustible in fly ash and slag. In order to solve the operation problems in Shanxi Xingneng Power Plant, such as slag dropping form dry slag machine, high slag temperature, the outage of slag crusher, and so on, adjustment tests of pulverized coal fineness were carried out for the mill. For example, by adjusting the separator speed of mill to change the fineness of pulverized coal; through keeping the oxygen steady at the furnace outlet to study the influence of pulverized coal fineness on the content of combustible in fly ash and slag, as well as the thermal efficiency of boiler. All these tests could provide a basis for the adjustment of rotary separator in medium speed mill. The results show that when the coal finess controlled within 17% and the evenness index of pulverized coal reaches 1.20, the coarse particles in pulverized coal significantly decrease which is beneficial to coal burnout. After the adjustment of pulverized coal fineness, the amount and temperature of slag decrease, which has improved the safety and economy of units.