喷雾降温对燃气轮机涡轮叶片损伤的影响

建立了燃气轮机高温涡轮叶片损伤评估模型,包括热力学性能计算模型、应力评估模型、热评估模型和交互损伤分析模型,无法测量参数由热力学性能计算模型计算,作为应力评估模型和热评估模型的输入。根据蠕变与疲劳损伤模型分析结果,对进气道内使用喷雾冷却降温的燃气轮机高温涡轮叶片进行损伤评估,比较了燃气轮机在不同转速以及负荷下,使用喷雾冷却系统前后,高温涡轮叶片损伤的变化,定量评估喷水量对高温叶片寿命的改善。结果表明:启用喷雾冷却系统可以大幅减小因蠕变造成的叶片损伤,在低负荷(30%)时损伤减小的幅度尤为明显,其预期寿命从40 000 h延长到50 000 h以上,可以大幅延长叶片的使用寿命;在夏季运行时(53%负荷),如果以减少蠕变损伤为目标,可以考虑增加喷水量,从40%～100%,叶片各级蠕变损伤最高可减小13.5%。

Effect of Spray Evaporative Cooling for the Damage of Gas Turbine Blades

Damage evaluation model of gas turbine blade was established,including thermodynamic performance calculation model,stress estimation model,thermal estimation model and interactive damage analysis model,to evaluate the effect of spray evaporative cooling on the creep and fatigue damage of high temperature blades.Unmeasured parameters are calculated by the thermodynamic performance calculation model,and used as the input of the stress estimation model and the thermal estimation model.According to the creep and fatigue analysis results,the damages of gas turbine blades before and after using the spray evaporative cooling system at different speeds and loads were compared,and the life of the gas turbine blades was quantitatively evaluated to guide the optimization and operation of the spray system.The result shows that the spray evaporative cooling system could greatly reduce the blade damage caused by creep,when the load was at 30%,the magnitude of damage reduction is particularly evident,and its life expectancy extends from 40 000 hours to more than 50 000 hours,which can significantly extend the service life of blades.In general operation in summer (53% load),in order to reduce the creep damage as the goal,one can consider increasing the amount of water from 40% to 100%,then the highest levels of blade creep damage can be reduced by 13.5%.