摘要
针对机组日常运行时仅通过监测固定点的温度来预防热应力的破坏,无法准确监测不同部位的温升,更无法确定热应力分布来判断因应力导致的破坏情况。以南方电网广州抽水蓄能电站的一台已投运机组为例,通过温度场分析和热-结构耦合场分析计算了其电机全域温升及转子结构的应力。研究结果确定了定子和转子的温度分布情况,以及实际运行时应重点监测温升的部位;评估了转子结构整体热应力分布,并确定了峰值应力位置,为检修计划的制定提供理论依据。
The pumped storage generator/motor often switches between multiple operating conditions frequently and unpredictably under daily operation,leading to acute temperature rise.The repetitive thermal stress could cause serious structural damage.Because the temperature monitoring system is only able to measure the temperature at some point,not only the temperature distribution of different components,but also the damage caused by thermal stress is not able to measure.In case study,the temperature distribution of a generator-motor under realistic operating conditions in Guangzhou pumped storage power plant is calculated by the temperature field analysis.And the temperature-structure coupled field analysis is used to calculate the thermal stress.The temperature distributions of different components are used to confirm the key point of temperature rise.And the location of maximum thermal stress is found at the slot-dovetail.Thus,well-founded maintenance strategies can be proposed for improving the detection of incipient failures in early stages.
引文
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