【作者】 马崇；

【导师】 荆洪阳；

【作者基本信息】 天津大学 ， 材料加工工程， 2005， 硕士

【摘要】 火力发电厂锅炉运行的可靠性是影响发电厂运行可靠性的首要因素,尤其是锅炉受热面管子的损坏泄漏对机组的安全运行影响最大,是火力发电厂的常见事故,一般占机组故障的60%-70%,因此,受热面管爆漏是影响机组安全发电的首要因素。锅炉受热面管由于设计、制造、安装、运行、检修、管理方面的问题以及长期在高温、高压、腐蚀、冲蚀恶劣条件下运行存在的老化等原因,爆漏损坏造成的停炉次数高于其它设备。只有掌握各种类型受热面管爆管的表面特征、组织特性、材质劣化的现象、内外壁结垢、腐蚀、疲劳的特点,才能有的放矢的进行监督检验工作,寻找有效的管理和技术防治对策,提高机组运行的可靠性,保障电网的稳定经济运行。本文对受热面管过热器、再热器、水冷壁、省煤器在不同条件下的爆漏进行了失效分析试验,采用宏观检查、壁厚测量、硬度试验、成分分析、室温拉伸试验、金相组织观察、扫描电镜等分析方法,对受热面管材料的成分、机械性能、微观组织进行了综合分析和研究。试验结果表明:受热面管的爆漏是材料、环境介质、温度、应力和运行工况多种因素综合作用的结果,本文总结了受热面管的损坏规律,按爆漏的原因,将受热面管的失效分为五类,为应力断裂、腐蚀、疲劳、磨损、质量控制失误,论述了各种失效类型现象、产生的原因和防止措施。更多还原

【Abstract】 The reliability of the boiler is primary factor of influencing the operation reliability of the thermal power plant , especially the failure of the boiler tube of heating surface is a serious influence on safe operation of the unit, it is a common accident of the thermal power plant, generally accounts for 60%-70% of unit’s troubles , the failure of the boiler tube of heating surface is a primary factor for safe operation of the power plant . Because of problems which produced in the design、manufacture、installation、operation、repairing、management of the boiler tube of heating surface and bad influences of high temperature、high pressure、corrosion、erodes in run for a long time , the times of the failure of the boiler tube of heating surface is higher than other equipments . When we grasp all kinds of features of surface feature、structural properties、the material degradation、scale、corrosion、fatigue of the tube of heating surface, we can have an object in view on the supervision and examination , find effective management and technology to prevention , improve the reliability of the unit operation , ensure the steady economical operation of the electric networks.This paper conclude the study on failure of superheater tube、reheater tube、water-wall tube、economizer tube in different conditions.The compositions、mechanical properties、microstructures of tube material of heating surface were systemically analyzed through visual examination、thickness measurement、hardness test、element analysis、tensile test、metallographic analysis and SEM , etc.The result shows that the failure of boiler tube of heating surface resulted from the comprehensive influences of material、environmental medium、temperature、pressure and operating mode . This paper has summarized the failure principles of boiler tube of heating surface, divided the failure into five kinds : stress fracture、corrosion、fatigue、erosion and failure of quality control according to the failure causes , described the causes and preventions of various failure types.更多还原