Study On The On-line Monitoring Of Thermal Stress For Large Capacity Steam Turbine Rotor

Improving the unit's safety is becoming the hot issue with the large capacity steam turbine taking part in load peak operation. The turbine rotor bears the highest thermal stress because of its mal-condition during the steam turbine's start-up and shutdown or load changing, and it has become the weakest spot. So enhancing the on-line monitoring of the thermal stress is fairly important.The one-dimensional and two-dimensional finite difference model of temperature field is built, and the thermal stress model is also built in this paper. The important factors of influencing the accuracy of the thermal stress are studied in detail. Such as heat transfer coefficient, material physical properties, stress concentration factor and steam measuring point. The thermal stress model is developed based on the integrated modular modeling software. Using the two-dimensional finite difference thermal stress model and the object C300/273-16.7/0.4/537/537 type made from the east stream turbine factory, the thermal stress of the situation of the rated load, changing load, shutdown, start-up are calculated on-line. The results are proper, which can meet the engineering requirement, and it has gained some practical value for large capacity steam turbine rotor on-line monitoring.