Abstract
The LP casing of DFSTW's Ultra-supercritical 1000MW steam turbine is such a structure: 1200mm end rotor blades, bearing seat is cantilever supported on end plate of casing, inner casing is supported on casing by cat's claw. It is very large (long,wide,high=8370×9360×7124mm). So it is very difficult to avoid resonating and impact-rubbing between movable and stationary parts of steam turbine. Based on FEA theory, a three dimensional finite element model of LP casing to analyze the deformation, stiffness, frequency and response has been developed. By using this method, Dong Fang Steam Turbine Works have designed a lot of LP casing, such as steam turbine exported to Middle DFSTW Market is 60Hz model, Ultra-supercritical 1000MW (1200mm end rotor blades) or 660MW generators of LIUHENG, JIAOZUO Power plant etc. in the operation, the bearing Vibration is small, and the stiffness and vibration performance of LP casing have reached the international leading level. Result of FEA calculate is conform with the fact. It shows the numerical analysis can provide usable data for LP casing designing and improving.
