Verification of Geometric Models of the LPC Rotor of the K-1000-60/3000 Turbine Unit Based on Natural and Critical Frequencies in the Ansys Software Complex

Abstract

One of the priority tasks of the energy industry is to ensure the reliable and safe operation of steam turbine units of thermal power plants and nuclear power plants. Given the difficult situation in the country, it is impossible to replace outdated equipment that has exhausted its design resource with new ones. As is known, the safety factor of the material taken into account during the design of steam turbine equipment was very approximate. At that time, there were no data on the operation of power equipment, which would have already worked for 200-220 thousand hours. in difficult operating conditions. The situation has changed now. There are power installations that have exhausted or are close to exhausting their design resource. By conducting experimental studies with metal samples of this equipment, it is possible to significantly clarify the physical and mechanical properties of steels and their damage due to operation. Therefore, the problem of extending the resource is becoming increasingly important. Computer modeling has greatly simplified the task of calculating the resource of the equipment. However, such a complex object as a steam turbine requires significant computing resources, and the calculation of equations in all finite element nodes is quite time-consuming. It is necessary to look for ways to rationalize calculation mathematical models. At the same time, the accuracy of the calculation should remain at a satisfactory level. In this work, were created simplified geometric models of the rotor of the LPC turbine unit К-1000-60/3000. The option is considered of replacing the working blades with equivalent distributed masses and toroidal rings. Verification of the obtained models based on critical rotation frequencies confirmed the possibility of replacing the working blades with distributed masses. On the other hand, the presence of toroidal rings of large radii leads to a significant reduction of critical frequencies in comparison with normalized values.