超超临界机组现场测量仪表及附属设备选型研究

Study on Type Selection for Field Measurement Instruments and Accessory Equipments of Ultra Supercritical Unit

超超临界机组高温高压参数测量所用热电偶、仪表导管和仪表阀门的选型目前尚无统一的标准或规定。针对超超临界参数的测量,分析和比较了热电偶保护管的设计、材质及与工艺管道的焊接方式;根据ASME标准确定了仪表导管的设计参数、相应的材质和管径规格;结合已投运超临界机组仪表阀门选用情况,提出了仪表一次阀和排污阀的型式。确保了应用在国电谏壁发电厂2×1 000 MW机组扩建工程上的热电偶、仪表导管和仪表阀门的使用安全性。

Currently,there are no unified standards or regulations for the type selection of the thermal couples,instrument tubes and valves for parameter measurements under high temperature and pressure in ultra-supercritical power plant units.For the measurement of the ultra supercritical parameters,the design,material and welding to the process pipeline of the thermal couple protection tube were analyzed and compared;the design parameter,corresponding material and specification of the diameter were determined according to the ASME standard;the type of the primary and blowdown valves for the instruments was proposed in combination with the valve selection practice in operating supercritical power plant units.Therefore,the safety of the thermal couples,instrument tubes and valves used in Jianbi 2×1 000 MW unit expansion project was guaranteed.