THERMAL AND STRAIN-STRESS STATE OF HIGH-PRESSURE ROTOR OF K-1000-60/3000 TURBINE OF NPP UNIT

Abstract

The policy of extending the exploitation-time of nuclear power plants is acceptable at the current stage of Ukraine’s energy development. This requires the determination of the actual resource status and reliability of the main equipment of nuclear power plants. According to regulatory documents, the extension of the service life-time of energy equipment requires a wide range of numerical studies, including the calculation of the thermal and strain-stress state of its main elements. The rotor of the high-pressure cylinder 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, 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 centrifugal forces have the greatest influence on the level of stress intensity.