Analysis Of BFPT High Speed Rotor For 1000mw Steam Turbine

The rotor is one of the most important part of steam turbine. The reliability of unit mostly depend on it. In the design of general rotor of steam turbine, the axial thrust force and other dynamic character are usually within designer's concern. While designing BFPT, the changing speed brings great challenges.With the rapidly development of 1000MW extra supercritical pressure units in China, which have obvious advantages of high-efficiency, saving-energy and low-pollution, the demand of matched 22.5MW BFPT is becoming bigger and bigger. It is important to prepare a reliable and efficient 22.5MW BFPT for the market.However, due to the great output of the 22.5MW BFPT, huge axial thrust force of rotor can hardly be balanced. If the double-flow design is taken, the costs of turbine manufacture and plant construction will highly rise with no advantages in marketing competition. On the other hand, due to the large scale of rotor rated speed, it is difficult to make the critical speed far away from rated speed. The measure to adjust critical speed will change the axial thrust force of rotor at the same time. A delicate circumstance has to be faced while designing the rotor of 22.5MW BFPT.This research is made for 22.5MW BFPT for 1000MW extra supercritical pressure power plant. Considering the great output, huge axial thrust force and large scale of speed of the rotor, calculations and analysis are made to investigate the axial thrust force and the dynamic character of the high speed rotor. The conflict between the axial thrust force and the critical speed is well solved. It is proved that the design of single casing and single flow is still suitable to 22.5MW BFPT. The security, stability and high efficiency of this BFPT can be guaranteed.