无密封风机的双进双出磨煤机正压直吹式制粉系统设计

No sealing fan designing technique in the double-inlet and double-outlet tobe mill positive pressured direct-fired pulverizing system

国电聊城电厂二期2×600MW超临界机组工程,设计煤质、校核煤质均为低挥发分贫煤,制粉系统采用了双进双出钢球磨煤机正压直吹系统。在初步设计阶段,每台炉设置了两台100%容量的密封风机,之后的施工图设计中,经过充分调研,制粉系统中取消了密封风机,磨煤机的密封风取自冷一次风。经一系列的设计优化,最终使磨煤机的密封风压力高于制造厂家的要求。从试运行一直到满负荷发电,现已运行近一年的时间,磨煤机没有出现漏风、漏粉现象,现场制粉系统运行良好。电厂节能、降耗效果显著。

The designed and calibrated coal type of the 2×600MW supercritical unit of Liaocheng power plant phase Ⅱ of China Guodian Group,were both low fugitive constituent lean coal.According to this,double-inlet and double-outlet tobe mill positive pressured direct-fired pulverizing system was adopted.During the preliminary design,according to'Technical code for designing fossil fuel power plants DL5000-2000',two sealing fans of 100% volume were chosen for each unit.After sufficient research in detailed design,the sealing fans were cancelled and the sealing air was provided by cold primary air.The designed pressure of sealing air was above the desire of the mill manufacturer after a series of optimization.From the trial operation to full load operation in 3 # unit of plant,more than a year,there are no air leakage and coal leakage.There are clear effect on energy-saving and emission-reduction.