600 MW亚临界机组中压调节阀阀碟套筒与阀盖连接螺栓断裂的原因分析及处理措施

Cause Analysis and Treatment of Breakage of Connecting Bolt of Disk Sleeve and Bonnet of Medium Pressure Regulating Valve in 600 MW Subcritical Unit

陕西府谷电厂是开发建设陕北煤电基地向华北地区送电的重要项目,也是“西电东送”北线方案的重要组成部分。府谷电厂工程对于缓解东部地区能源资源、交通运输、节能环保等压力,提高能源安全保障能力,具有十分重要的作用,符合建设“煤电一体化”的能源政策,符合国家“西电东送”、“西部大开发”的发展战略。同时建设本工程可充分发挥当地资源优势,带动地方经济的发展,创造良好的经济效益。因此,本电厂在设备的选择和平时的作业上要求也甚是严格。而东方汽轮机厂生产的NZK600-16.7/538/538型汽轮机运行中发生中压调节阀阀碟套筒与阀盖连接螺栓断裂的设备事故,对电厂的安全稳定和经济运行造成影响,文章主要介绍该型号汽轮机中压调节阀(图号D600B-265000A)在运行中阀碟套筒与阀盖连接螺栓断裂的原因分析,处理改造方案及改造后的效果对比,通过提高螺栓材质,延长了设备的使用寿命,提高重要主机设备可靠性。

Shaanxi Fugu Power Plant is an important project for the development and construction of coal-electric power bases in northern Shaanxi to send power to North China,and it is also an important part of the North-line project of“West-to-East Power Transmission”.Fugu Power Plant Project has played a very important role in alleviating the pressures on energy resources,transportation,energy conservation and environmental protection in the eastern region,and improving energy security support capabilities.It is in line with the construction of a“coal-electricity integration”energy policy and is in line with the national“West-East Power Transmission.”“Development Strategy for Western Development”.At the same time,the construction of this project can give full play to the advantages of local resources,drive the development of the local economy,and create good economic returns.Therefore,the requirements for equipment selection and peacetime operations at the power plant are also very strict.In the operation of the NZK600-16.7/538/538 steam turbine produced by the Dongfang Steam Turbine Works,equipment accidents involving the fracture of the disk sleeve and the bonnet connecting bolts of the medium pressure regulator valve discrepancies affect the safety,stability and economic operation of the power plant.The analysis of the reasons for the rupture of the valve disc sleeve and valve cap connecting bolt during the operation of this type of turbine medium pressure regulating valve(drawing number D600B-265000A),the treatment transformation program and the comparison of the effect after the transformation,and the extension of the equipment by improving the bolt material Service life,improve the reliability of important host equipment.