提升1000MW机组磨煤机进出口温度的措施研究

在研究典型混煤及印尼煤热重-红外特性、中速磨煤机内温度分布、可燃性气体析出及爆燃问题的基础上,对某1 000 MW机组成功实施了提升磨煤机进、出口气流温度的试验,结果表明：存在于磨煤机及煤粉管道内的可燃性气体通常不会发生爆燃问题;一次热风在进入磨煤机研磨区域后迅速降低为接近磨煤机出口气流的温度;以热重着火温度与红外CO析出温度的平均值作为磨煤机进口热风的理论控制温度暂时较为妥当;磨煤机的出口气流温度从75℃提升到96℃（三仓优混煤）、65℃提升到76℃（二仓稍低热值印尼煤）、66℃提升到79℃（一仓稍高热值印尼煤）时,排烟温度可以下降约6.3℃;现场试验时的磨煤机出口气流温度虽然都突破了原有规程的限值,但仍过于谨慎,在理论与实践中其出口温度均可以更高。

Study on Increasing Inlet and Outlet Temperature of Pulverizer of 1000 MW Units

The result shows that flammable gasses existing in pulverizer and its outlet pipes were unable to defla- grate generally; once the primary hot air entered the milling area, its temperature approaches to pulverizer out- let airflow rapidly; taking the mean of coal ignition temperature tested by thermo-gravimetric analysis and CO exhalation temperature tested by infrared spectroscopic analysis as the theoretical controlling number of pulver- izer inlet hot air temperature was temporarily reasonable; when the pulverizer outlet airflow temperature in- creased from 75℃ to 96℃（three hoppers of bended coal）, 65℃ to 76℃（two hoppers of indonesia coal with low- er thermalvalue）, from 66℃ to 79℃ （one hopper of Indonesian coal with higher thermalvalue）, the unit exhaust gas temperature could be decreased by 6.3℃; the pulverizer outlet airflow temperature broke through the exist- ing regulation, however it＇s over-cautious and the outlet airflow＇s temperature can be higher theoretically or practically.