| 摘要 |
PROBLEM TO BE SOLVED: To provide a steam turbine including a stress relaxation groove in a rotor. SOLUTION: The steam turbine 1 has the stress relaxation groove 8 disposed in the area of a balance piston 6 and extending in a circumferential direction of the rotor 2. The stress relaxation groove 8 is disposed upstream in an axial direction with respect to, particularly, an inlet flow passage 5 so that the stress relaxation groove 8 is disposed to the rotor 2 outside the area where a steam flow 11 flows from the inlet flow passage into a blade-row flow passage 1'. The stress relaxation groove is disposed in an area where the maximum thermal stress can be generated in the rotor 2, with respect to a first blade row 12. The stress relaxation groove 8 includes a cover reducing swirling currents and a device suppressing heating of the groove or a device actively cooling the groove. The steam turbine minimizes deterioration in turbine performance, and increases the number of times of starting and stopping operation of the stream turbine without risk. COPYRIGHT: (C)2011,JPO&INPIT |
