储能用汽轮发电机护环通风孔对其疲劳寿命影响的研究

Impact Study of Vent Hole Design on Fatigue Life in Guard Rings of Frequently Starting-stopping Steam Turbine Generators

通过在汽轮发电机转子护环上设置通风孔,可以显著改善转子端部的冷却条件,特别是发电机转子端部使用外部冷却型式,其线圈温度最高点处于转子端部的护环下。然而,在护环钻孔会导致护环在通风孔附近产生应力集中,尤其是在发电机需要频繁启动和停止的工况下(如空气储能发电应用中),可能会导致护环出现疲劳损伤的风险,故研究护环开孔对其疲劳寿命的影响至关重要。本研究遵循ASME设计规范的疲劳校核流程,运用有限元方法进行应力分析,并根据ASME设计规范的应力线性化、疲劳筛分程序及疲劳损伤计算理论对有限元计算结果进行处理和疲劳损伤计算,从而得到了护环开孔对其疲劳寿命的影响结果,通过优化设计,提出了改进护环疲劳寿命的方法。

Implementing ventilation holes in the rotor guard ring of steam turbine generators significantly enhances the cooling conditions at the rotor end,especially for generators where the rotor end employs an external cooling style,and the highest temperature of the coil is located beneath the guard ring at the rotor end.However,drilling holes in the guard ring leads to stress concentration near these ventilation holes.This is particularly concerning for generators that require frequent starting and stopping,such as in peak shaving operations or in air energy storage power generation applications,as it may pose a risk of fatigue damage to the guard ring.Therefore,investigating the impact of these holes on the fatigue life of the guard ring is of paramount importance.This study follows the fatigue verification process outlined in the ASME design standards,employing finite element methods for stress analysis.It further applies ASME’s standards for stress linearization,fatigue screening procedures,and fatigue damage calculation theory to process the finite element analysis results.This approach yields insights into the impact of the drilled holes on the guard ring’s fatigue life.Through optimized design,the study proposes methods to improve the fatigue life of the guard ring.