褐煤掺烧锅炉制粉系统出力的研究及改造

Research and Transformation of Pulverizing System Output of Lignite Mixedly Burning Boiler

以350 MW亚临界烟煤机组为例,进行制粉系统研磨出力和干燥出力计算,分析了烟煤锅炉褐煤掺烧对制粉系统出力的影响。根据结果,由于水分高、热值低,可磨性差,燃用混煤时研磨出力下降,干燥出力下降。针对制粉系统干燥出力不足的问题,提出了一次风再热系统。改造系统利用三抽蒸汽加热热一次风,提高始端干燥剂物理热。改造系统具有良好的经济效益,对机组能耗指标基本没有影响。

Taking the 350 MW bituminous coal unit as an example,the grind output and the dry output of the pulverizing system were calculated,and the influence of lignite mixedly burning at the pulverizing system was analyzed.According to the results,because of high moisture and low calorific value,the grinding ability is poor,the grind output and the dry output is decreased when burning lignite mixedly coal.In view of the shortage of dry output in the pulverizing system,the primary air reheat system is put forward.The reform system uses three steam to heat the primary air to increase the physical heat of the drying agent.The reform system has good economic benefit,and has no effect on the energy consumption index of the unit.