3-4号磨煤机12C-E.doc

印度腾达电站#3、4炉磨煤机目前存在的主要问题The existing problems of coal mills for boiler#3 and boiler#4 #3、4炉磨煤机自投运以来，频繁发生磨煤机振动、变加载不能正常调压、出力不足、堵塞、漏粉等问题，对机组的安全运行带来极大隐患。 Since the coal mills (for boiler#3and boiler#4) were put in service, there are many problems, such as: abnormal vibration, difficult adjustment with variable load, insufficient output, blockage, and leakage and so on, which cause serious incipient faults for safe operation of the unit. 1、动、静环间隙调整问题 1. About the adjustment of clearance between moving and fixed nozzles 根据现场检查情况发现，在前期解决动环与静环之间无间隙问题时，贵公司检修人员直接将磨煤机的动环单边切割35mm。 It is found on site during check that the maintenance personnel adopted the measurement, directly side cutting the moving nozzle up to 35mm, to solve the problem that there is no clearance between moving and fixed nozzles in the early. 动环与静环之间无间隙是由于安装找正有误造成的，即由于磨煤机的动静之间的平衡中心没有找好，从而引起磨煤机的动环与静环之间的间隙一边大一边小，旋转部分与静止部分的间隙应是8±1.25 mm。 The above problem was resulted from the incorrect alignment during installation, that is, the balance center between moving and fixed parts was not found, which result in the different clearances in the circle direction of moving or fixed rings. The clearance between moving and fixed parts should be 8±1.25 mm. 由于目前磨煤机的动环单边被切割35mm ，会对磨煤机级机组造成以下影响： At present, side cutting up to 35mm on moving part can cause the following problems: 1）、造成煤粉均匀性和煤粉细度无法保证，降低磨煤机的出力。由于磨煤机的煤粉细度不均，整个锅炉的燃烧提前或延后，严重时锅炉的主汽温及再热汽温是难以保证，影响机组的效率，严重时机组的负荷及安全性无法得到有效的保证。 1). The uniformity and fineness of pulverized coal can not be guaranteed and the output of coal mill is reduced. The non-uniformity of the pulverized coal pre-acts or delays the combustion in the furnace; if serious, the main steam temperature and reheated steam temperature can not be guaranteed which badly reduces the efficiency of the unit, and even the load and safety of the unit can not be guaranteed effectively. 2）、由于动环与静环之间的间隙成为一边大一边小，一次风的均匀性受到挑战，致使进入煤粉分离器的风粉混合物不均匀，磨煤机内形成了涡流区，磨煤机的出口处各个燃烧器的煤粉浓度不一致，其各个粉管道一次风速不一致，造成锅炉燃烧的局部恶化，严重时有可能造成锅炉灭火。 2). Th