1350MW机组电除尘器选型及其钢支架热膨胀影响控制

Type Selection on 1350 MW Electrostatic Precipitator and Its Steel Frame Control on Thermal Expansion

燃煤火电机组的最新技术发展带动了相应辅机设备的选型及设计技术的发展。以安徽某1 350 MW高低位分轴布置超超临界二次再热机组配置的大型电除尘器为例,对比分析了不同电除尘器选型方案(每台炉配套2台四室五电场、3台三室五电场、4台双室五电场);基于有限元分析软件,针对有较好经济性的四室五电场大型电除尘器,分析了热膨胀量大引起的强度不足问题,并设计了立柱预偏心结构。结果表明:热膨胀对超大型电除尘器钢支架的强度影响较大,立柱预偏心结构可有效解决这一问题。

The recent technology development of coal-fired generation unit drives the progress of corresponding auxiliary equipments and their design techniques.Take the example of the electrostatic precipitator(ESP)installed in a 1350 MW double reheat ultra supercritical coal-fired unit in Anhui province with cross compound steam turbine arrangement featured by separated shafts with elevated and conventional layout.The schemes for ESP type selection are analyzed and different combinations are compared,i.e.,two sets with four-chamber and five-field,three sets with three-chamber and five-field,four sets with two-chamber and five-field of ESPs.Especially regarding the four-chamber ESP with better economic performance,the problem of insufficient strength caused by thermal expansion is analyzed by a finite element analysis software package and then the pre-eccentricity of pivots is developed.The result shows that the thermal expansion has significant impacts on the strength of the steel frame of large size ESPs and the pre-eccentricity of pivots can effectively reduce the internal force and deformation.