凝汽器换热管断裂损伤分析与综合防治
|
摘要
凝汽器是电站汽轮机组中重要的换热设备,换热管断裂损伤是其主要故障模式,严重影响机组可靠运行。本文针对某电站凝汽器故障问题,通过分析换热管调试阶段和商业运行阶段的断裂损伤情况,逐一排查可能的致伤原因,最后确定此次事故为流体弹性激振诱发的疲劳断裂,而厂家对凝汽器设计的安全裕度考虑不足,理论设计与现场实际产生了偏差,是导致换热管发生非预期断裂损坏的根本原因。针对换热管断裂损伤时的运行工况和损伤区域,提出加装防振条、局部区域预防性堵管、仿真计算与应变测量等一系列综合防治措施,可有效降低换热管断裂损伤的风险,提高凝汽器设备的可靠性。
Condenser is an important heat exchanger device in power plant steam turbines, and fracture damage of heat exchanger tube is its main failure mode, which seriously affects the reliable operation of the unit. Aiming at solving the problem of condenser failure in a power station, by analyzing the fracture damage of the heat exchanger tube during commissioning and commercial operation stages, the possible causes of the damage are investigated one by one. Finally, the fatigue fracture induced by hydro elastic excitation is considered as the major reason. In fact, the safety margin of the condenser design is insufficiently considered by the manufacturer, and the deviation between theoretical design and field practice results is the primary cause for the unexpected fracture damage. Against the operation condition and damage area of the heat exchanger tube when it is damaged by fracture, a series of comprehensive prevention measures are put forward, such as installing the anti-vibration strip and preventive blockage in local area, and carrying out simulation calculation and strain measurement, which can effectively reduce the risk of the heat exchanger tube fracture damage and improve the reliability of condenser equipment.
Condenser is an important heat exchanger device in power plant steam turbines, and fracture damage of heat exchanger tube is its main failure mode, which seriously affects the reliable operation of the unit. Aiming at solving the problem of condenser failure in a power station, by analyzing the fracture damage of the heat exchanger tube during commissioning and commercial operation stages, the possible causes of the damage are investigated one by one. Finally, the fatigue fracture induced by hydro elastic excitation is considered as the major reason. In fact, the safety margin of the condenser design is insufficiently considered by the manufacturer, and the deviation between theoretical design and field practice results is the primary cause for the unexpected fracture damage. Against the operation condition and damage area of the heat exchanger tube when it is damaged by fracture, a series of comprehensive prevention measures are put forward, such as installing the anti-vibration strip and preventive blockage in local area, and carrying out simulation calculation and strain measurement, which can effectively reduce the risk of the heat exchanger tube fracture damage and improve the reliability of condenser equipment.
引文
[1]张卓澄.大型电站凝汽器[M].北京:机械工业出版社,1993:260-268.ZHANG Zhuocheng.Large power plant condenser[M].Beijing:China Machine Press,1993:260-268.
[2]汪国山.电站凝汽器热力性能数值仿真及其应用[M].北京:中国电力出版社,2009:25-29.WANG Guoshan.Numerical simulation of thermo-dynamic performance of power station condenser and its application[M].Beijing:China Electric Power Press,2009:25-29.
[3]穆尔·西弗丁.低压汽轮机和凝汽器的气动热力学[M].翁泽民,译.西安:西安交通大学出版社,1992:11-17.MOORE M J,SIEVERDING C H.Aerodynamic thermodynamics of low pressure steam turbines and condensers[M].WENG Zemin,translated.Xi’an:Xi’an Jiaotong University Press,1992:11-17.
[4]吴文龙,张小霓,张春雷,等.凝汽器腐蚀与结垢控制技术[M].北京:中国电力出版,2012:88-91.WU Wenlong,ZHANG Xiaoni,ZHANG Chunlei,et al.Condenser corrosion and structure control technology[M].Beijing:China Electric Power Press,2012:88-91.
[5]杨善让.汽轮机凝器设备及运行管理[M].北京:水利电力出版社,1991:32-33.YANG Shanrang.Steam turbine condensing equipment and operation management[M].Beijing:Water Conservancy and Electricity Publishing House,1991:32-33.
[6]陈自强,杨璋.某型核电汽轮机凝汽器半侧运行分析[J].热力发电,2018,47(10):146-150.CHEN Ziqiang,YANG Zhang,Analysis of the half-side operation of a nuclear power steam turbine condenser[J].Thermal Power Generation,2018,47(10):146-150.
[7]姬鄂豫,朱小红,姚杰新.管材缺陷与微生物对凝汽器不锈钢管的腐蚀及其协同作用[J].热力发电,2011,40(12):38-42.JI Eyu,ZHU Xiaohong,YAO Jiexin.Exploring analysis of corrosion concerning stainless steel tubes in condenser due to tubing defects and microbe as well as their synergetic effect[J].Thermal Power Generation,2011,40(12):38-42.
[8]乐俊,菅从光,张辉.火电厂循环水系统优化运行研究[J].热力发电,2008,37(6):9-12.LE Jun,JIAN Congguang,ZHANG Hui.Study on optimal operation of circulating water system in thermal power plant[J].Thermal Power Generation,2008,37(6):9-12.
[9]午旭杰,肖波.秦山第三核电厂汽轮机高压导汽管疏水改进[J].热力发电,2009,38(7):72-75.WU Xujie,XIAO Bo.Modification of drain mode in high-pressure steam conducting pipe to steam turbines of Qinshan nuclear power plant No.3[J].Thermal Power Generation,2009,38(7):72-75.
[10]褚孝荣,单世超.核电厂汽轮机凝汽器钛管涡流探伤问题及分析[J].汽轮机技术,2015,57(3):234-236.CHU Xiaorong,SHAN Shichao.Analysis of eddy current test of titanium tubes for a turbine condenser in NPP[J].Turbine Technology,2015,57(3):234-236.
[11]张水桃,许晔,鲁前奎.核电汽轮机凝汽器冷却管避免振动碰摩的预防措施[J].东方汽轮机,2014(3):1-4.ZHANG Shuitao,XU Ye,LU Qiankui.Preventive measure of avoiding condenser tube’s vibration friction defect for nuclear turbine[J].Dongfang Turbine,2014(3):1-4.
[12]CHEN S S.Instability mechanisms and stability criteria of a group pf circular cylinder subjected to cross flow.Part I:theory[J].ASME Journal of Vibration,Acoustics,Stress,Reliability in Design,1983,105:51-58.
[13]CHEN S S.Instability mechanisms and stability criteria of a group pf circular cylinder subjected to cross flow.Part II:numerical results and discussions[J].ASMEJournal of Vibration,Acoustics,Stress,Reliability in Design,1983,105:253-260.
[14]PETTIGREW M J,GORMAN D J.Vibration and heat exchanger tube bundles in liquid and two-phase cross flow[J].Pressure Vessels and Piping Division,1980,52:59-110.
[15]黄美华,姜成仁,石建中.多壳体凝汽器局部单列运行下压差分析[J].汽轮机技术,2015,57(4):302-306.HUANG Meihua,JIANG Chengren,SHI Jianzhong.Pressure calculation in asymmetric heat-exchange for multi-shell condenser[J].Turbine Technology,2015,57(4):302-306.
[16]沈杏初,张卓澄.略论秦山核电厂凝汽器的研制[J].热能动力工程,1988,3(5):42-48.SHEN Xingchu,ZHANG Zhuocheng.A brief discussion on the development of the condenser of Qinshan nuclear power plant[J].Journal of Engineering for Thermal Energy and Power,1988,3(5):42-48.
[17]袁小会,蔡逸飞.凝汽器钛管断裂失效分析[J].武汉工程大学学报,2014,36(3):53-57.YUAN Xiaohui,CAI Yifei.Failure analysis on titanium tubes in condenser[J].Journal of Wuhan Institute of Technology,2014,36(3):53-57.
[18]李勇,张卫会,张欣刚.300 MW核电汽轮机凝汽器动态过程的数值分析[J].核动力工程,2002,23(4):50-54.LI Yong,ZHANG Weihui,ZHANG Xingang.Numerical analysis of dynamic process of condenser for 300 MWnuclear steam turbine[J].Nuclear Power Engineering,2002,23(4):50-54.
[19]汪国山,毛新青,田子平,等.125 MW汽轮机凝汽器内流体流动和传热特性的数值分析[J].动力工程学报,2001,21(3):1263-1266.WANG Guoshan,MAO Xinqing,TIAN Ziping,et al.Nu(m)erical analysis of the fluid flow and heat transfer properties of the condenser of 125 MW steam turbine[J].Power Engineering,2001,21(3):1263-1266.
[20]汪国山,毛新青,胡国新,等.电站凝汽器内流场和传热的准三维数值计算程序PPOC3.0的开发研究[J].动力工程,2001,21(5):1450-1454.WANG Guoshan,MAO Xinqing,HU Guoxin,et al.Development and research of quasi-three-dimensional PPOC3.0 program for flow field and heat transfer in power plant condense[J].Power Engineering,2001,21(5):1450-1454.
[2]汪国山.电站凝汽器热力性能数值仿真及其应用[M].北京:中国电力出版社,2009:25-29.WANG Guoshan.Numerical simulation of thermo-dynamic performance of power station condenser and its application[M].Beijing:China Electric Power Press,2009:25-29.
[3]穆尔·西弗丁.低压汽轮机和凝汽器的气动热力学[M].翁泽民,译.西安:西安交通大学出版社,1992:11-17.MOORE M J,SIEVERDING C H.Aerodynamic thermodynamics of low pressure steam turbines and condensers[M].WENG Zemin,translated.Xi’an:Xi’an Jiaotong University Press,1992:11-17.
[4]吴文龙,张小霓,张春雷,等.凝汽器腐蚀与结垢控制技术[M].北京:中国电力出版,2012:88-91.WU Wenlong,ZHANG Xiaoni,ZHANG Chunlei,et al.Condenser corrosion and structure control technology[M].Beijing:China Electric Power Press,2012:88-91.
[5]杨善让.汽轮机凝器设备及运行管理[M].北京:水利电力出版社,1991:32-33.YANG Shanrang.Steam turbine condensing equipment and operation management[M].Beijing:Water Conservancy and Electricity Publishing House,1991:32-33.
[6]陈自强,杨璋.某型核电汽轮机凝汽器半侧运行分析[J].热力发电,2018,47(10):146-150.CHEN Ziqiang,YANG Zhang,Analysis of the half-side operation of a nuclear power steam turbine condenser[J].Thermal Power Generation,2018,47(10):146-150.
[7]姬鄂豫,朱小红,姚杰新.管材缺陷与微生物对凝汽器不锈钢管的腐蚀及其协同作用[J].热力发电,2011,40(12):38-42.JI Eyu,ZHU Xiaohong,YAO Jiexin.Exploring analysis of corrosion concerning stainless steel tubes in condenser due to tubing defects and microbe as well as their synergetic effect[J].Thermal Power Generation,2011,40(12):38-42.
[8]乐俊,菅从光,张辉.火电厂循环水系统优化运行研究[J].热力发电,2008,37(6):9-12.LE Jun,JIAN Congguang,ZHANG Hui.Study on optimal operation of circulating water system in thermal power plant[J].Thermal Power Generation,2008,37(6):9-12.
[9]午旭杰,肖波.秦山第三核电厂汽轮机高压导汽管疏水改进[J].热力发电,2009,38(7):72-75.WU Xujie,XIAO Bo.Modification of drain mode in high-pressure steam conducting pipe to steam turbines of Qinshan nuclear power plant No.3[J].Thermal Power Generation,2009,38(7):72-75.
[10]褚孝荣,单世超.核电厂汽轮机凝汽器钛管涡流探伤问题及分析[J].汽轮机技术,2015,57(3):234-236.CHU Xiaorong,SHAN Shichao.Analysis of eddy current test of titanium tubes for a turbine condenser in NPP[J].Turbine Technology,2015,57(3):234-236.
[11]张水桃,许晔,鲁前奎.核电汽轮机凝汽器冷却管避免振动碰摩的预防措施[J].东方汽轮机,2014(3):1-4.ZHANG Shuitao,XU Ye,LU Qiankui.Preventive measure of avoiding condenser tube’s vibration friction defect for nuclear turbine[J].Dongfang Turbine,2014(3):1-4.
[12]CHEN S S.Instability mechanisms and stability criteria of a group pf circular cylinder subjected to cross flow.Part I:theory[J].ASME Journal of Vibration,Acoustics,Stress,Reliability in Design,1983,105:51-58.
[13]CHEN S S.Instability mechanisms and stability criteria of a group pf circular cylinder subjected to cross flow.Part II:numerical results and discussions[J].ASMEJournal of Vibration,Acoustics,Stress,Reliability in Design,1983,105:253-260.
[14]PETTIGREW M J,GORMAN D J.Vibration and heat exchanger tube bundles in liquid and two-phase cross flow[J].Pressure Vessels and Piping Division,1980,52:59-110.
[15]黄美华,姜成仁,石建中.多壳体凝汽器局部单列运行下压差分析[J].汽轮机技术,2015,57(4):302-306.HUANG Meihua,JIANG Chengren,SHI Jianzhong.Pressure calculation in asymmetric heat-exchange for multi-shell condenser[J].Turbine Technology,2015,57(4):302-306.
[16]沈杏初,张卓澄.略论秦山核电厂凝汽器的研制[J].热能动力工程,1988,3(5):42-48.SHEN Xingchu,ZHANG Zhuocheng.A brief discussion on the development of the condenser of Qinshan nuclear power plant[J].Journal of Engineering for Thermal Energy and Power,1988,3(5):42-48.
[17]袁小会,蔡逸飞.凝汽器钛管断裂失效分析[J].武汉工程大学学报,2014,36(3):53-57.YUAN Xiaohui,CAI Yifei.Failure analysis on titanium tubes in condenser[J].Journal of Wuhan Institute of Technology,2014,36(3):53-57.
[18]李勇,张卫会,张欣刚.300 MW核电汽轮机凝汽器动态过程的数值分析[J].核动力工程,2002,23(4):50-54.LI Yong,ZHANG Weihui,ZHANG Xingang.Numerical analysis of dynamic process of condenser for 300 MWnuclear steam turbine[J].Nuclear Power Engineering,2002,23(4):50-54.
[19]汪国山,毛新青,田子平,等.125 MW汽轮机凝汽器内流体流动和传热特性的数值分析[J].动力工程学报,2001,21(3):1263-1266.WANG Guoshan,MAO Xinqing,TIAN Ziping,et al.Nu(m)erical analysis of the fluid flow and heat transfer properties of the condenser of 125 MW steam turbine[J].Power Engineering,2001,21(3):1263-1266.
[20]汪国山,毛新青,胡国新,等.电站凝汽器内流场和传热的准三维数值计算程序PPOC3.0的开发研究[J].动力工程,2001,21(5):1450-1454.WANG Guoshan,MAO Xinqing,HU Guoxin,et al.Development and research of quasi-three-dimensional PPOC3.0 program for flow field and heat transfer in power plant condense[J].Power Engineering,2001,21(5):1450-1454.