Analysis of optimization operation for ultra-supercritical pressure generating units

Main parts of the unit bears great temperature variation when turbine starts up, shuts down or operates under shaving peaking, which generates alternating thermal stress in rotator. The turbine operation experience indicates that alternating thermal stress is the key fact influencing ability of turbine to adapt to load variation and span loss. To a considerable degree, low cycle thermal fatigue span of the turbine stands for span of the whole unit, thus thermal calculation and monitor of turbine rotator is of great importance. This paper analyzes features of 600MW usc turbine unit in Hanshan power plant, calculates thermal parameter and heat transfer coefficient under load varioation in each level, and adopts finite element method to simulates temperature field and stress field when shuts down, to find out dangerous moments and points, as reference to guide turbine operation when shuts down.