Study and Optimization of existing design of LP turbine’s Component

Abstract

The work presented has been carried out in organization involved with design and manufacturing of steam turbine ranging from 200MW to 800MW. The turbine of certain range are manufactured as per the same design, i.e. the design of turbine for 600MW & 800MW is identical with all aspects. The design calculations are performed based on 800MW & they are use for 600MW plant, may be a conservative approach. The presented work is concern with modification in the design of steam deflector, steam chamber, LP Turbine, inner casing and LP Turbine outer casing for 660MW capacity based on available design of this components for 800MW capacity. Geometric modelling of all components are prepared using NX9.0 and solidedge software using standard design used for 800MW Turbine. FEA analysis of all the components has been carried out using Ansys15.0 software by applying working boundary condition. Maximum induced stress results are compared with the allowable stress of the material, and factor of safety is calculated to compare the result with certain standards. Optimization of components is performed, if factor of safety is higher compared to allowable standards. Thickness of components are reduced without disturbing the flow path, and analysis is carried out for all modified design. Resultant stress is compared with allowable stress to find factor of safety which is compared with standards. The optimized model is selected which is having factor of safety near by the allowable standards. The Optimization of steam deflector, steam chamber, Inner casing and outer casing is carried out in the work presented. It is noted that percentage material saving is 10.26% for steam deflector, 4.16% for steam chamber, 3.73% for inner casing upper half and 3.63% for inner casing lower half.