The Strain-Stress State of K-1000-60/3000 Turbine Rotor for Typical Operating Modes

Abstract

The extension of the exploitation-time of nuclear power plants over the park service life-time requires the verification of the main elements of power equipment that determine the resource characteristics. According to the regulatory documents, the extension of the service life-time of steam turbine equipment requires the calculation of the thermal and stress-strain state of its main elements, namely the high-pressure rotor. The numerical mathematical study of high-pressure rotor of the steam turbine K-1000-60/3000 is investigated in the paper. The boundary task of unsteady heat conduction for typical operating conditions of a steam turbine installation is considered. To solve differential heat conduction equations, a finite-element method of discretization of the computational domain was used. The strain-stress state of the high-pressure rotor is calculated with taking into account the combined effect of temperature stresses, irregularity of the temperature field, stresses from pressure and centrifugal forces. The calculation of the nominal mode of exploitation regime is performed in a quasi-stationary setting. The calculation of the variable modes of operation is performed in a non-stationary setting. It has been established that when operating at exploitation conditions that are close to the nominal regime, the zones of maximum stress intensity concentration are axial bore in the area of the fourth and fifth pressure stages. At exploitation in variable operating modes, frequent stress concentrators are discharge openings and fillet transitions of all stages. It has been established by calculation that for a high-pressure rotor of a K-1000-60/3000 steam turbine, the maximum of stress intensity is 158 MPa at nominal operating mode. At variable operating modes, the value of the intensity of the conditional elastic stresses does not exceed 226-263 MPa for all types of turbine launches