某燃气轮机涡轮叶片维修周期方案设计

Maintenance Schemes Design of Gas Turbine Blades

以某型燃气轮机机组为例,对其涡轮叶片维修周期制定方法进行研究。基于准三维方法获得涡轮叶片运行各时刻温度场分布,通过有限元分析获得涡轮叶片应力/应变场分布,并计算6只叶片的低循环疲劳和蠕变寿命,根据线性累积损伤法则获得6只叶片的疲劳/蠕变交互曲线。结合该机组的实际运行工况以及涡轮叶片的疲劳/蠕变交互曲线,并采用西门子等效运行小时方法,对比了4种不同的维修周期方案对机组运行可靠性和维修经济性的影响,结果表明,每隔24000EOH或750Cycles进行涡轮叶片维修的方案为最佳。

Taking a gas turbine unit as an example,the method of determining the maintenance cycle of turbine blades is studied.Based on the quasi three-dimensional method,the temperature field distribution of the turbine blade at each time of operation is obtained,and the stress/strain field distribution of the turbine blade is obtained through the finite element analysis.The low cycle fatigue and creep life of six blades are calculated,and the fatigue-creep interaction curve of six blades is obtained according to the linear cumulative damage law.Combined with the actual operation mode of the unit and the fatigue-creep interaction curve of turbine blades,and using the Siemens equivalent operation hour method,the influence of four different maintenance schemes on the operation reliability and maintenance economy of the unit is compared.The results show that the maintenance scheme 24000EOH or 750Cycles is the best.