Thermal stress analysis of the parting plane flange joint of an industrial steam turbine

Abstract

A typical 14 MW steam turbine casing is analysed using a range of flange parameters and heating conditions with three-dimensional and two-dimensional models, in order to find the contact pressures and thermal stresses during transient thermal operations. Thermal stresses are also calculated with simple analytical formulae which are available in literature. Two-dimensional and analytical results are compared with three-dimensional results, and some correction factors are suggested. These correction factors can be used in day to day design work to obtain quick and simple solutions. Contact behaviour of the parting plane flange under transient thermal loads is studied using ‘gap’ elements available in the application software ‘NISA’.