Mitsubishi Heavy Industries Limited

Naoki Hagi

Yasuoki Tomita

Kenichi Arase

Taku Ichiryu

Hiroki Fukuno

Ryotaro Magoshi

Koichi Akagi

Toshishige Ai

Tatsuji Takahashi

Provided is a gas turbine plant that enables active clearance control for ensuring tip clearance of first-stage turbine rotor blades required during start-up and for achieving the minimum tip clearance during load operation. In a gas turbine plant including a cooler in an air system used for cooling second-stage turbine stator blades, a first-stage segmented ring and a second-stage segmented ring that oppose tips of first-stage turbine rotor blades and second-stage turbine rotor blades are supported by the same blade ring member, and a cooling-air for the second-stage turbine stator blades forms a cooling air flow cooling the blade ring, to control thermal expansion of the blade ring and to control the clearance with respect to the tips.

Gas turbine plant

Gas turbine rotor blade tip loss is reduced and loss caused by leakage of working fluid through gap between members constituting an annular flow passage is reduced. Turbine (AT) of a gas turbine (GT) constituting a combined cycle plant (CC) is supported to a turbine casing ( ) to be expandable or contractible in turbine shaft ( ) radial direction. First blade ring ( ) corresponds to first stage turbine stator blades (TS ) and rotor blades (TR ) and comprises a first heating medium flow passage ( P) for steam circulation therein. Second blade ring ( ) corresponds to second stage turbine stator blades (TS ) and rotor blades (TR ) and comprises a second heating medium flow passage ( P) for steam circulation therein. Further provided is a communication member ( ) for connecting the first blade ring ( ) and second blade ring ( ) to each other and for communicating the first heating medium flow passage ( P) and second heating medium flow passage ( P) with each other.

Combined cycle plant with gas turbine rotor clearance control

A clearance control system for a turbine seal optimizes a clearance by controlling the change in the clearance during a run due to a thermal elongation by cooling the sealing air. The air from a compressor is cooled by a cooler 12 and is guided via an outer shroud 22 and a tube 28 in a stationary blade 21 into a cavity 26 in an inner shroud 23. The air flows through a space 34 from a seal portion 36 to the outside and through a seal ring 25 and a space 35 from a seal portion 37 to the outside to seal the inner side of the inner shroud 23 from a hot combustion gas. A clearance .delta.H between a stationary portion and a rotary portion changes due to a thermal elongation. A clearance measuring sensor 14 monitors the clearance .delta.H without intermission. When the clearance .delta.H is large, the control unit 10 opens the flow regulator valve 11 to cause the air to bypass the cooler 12. When the clearance .delta.H is small, the control unit 10 closes the valve 11 to control the thermal elongation so that the clearance .delta.H may be optimized at all times. As a result, the sealing performance can be improved to avoid the contact.

Seal active clearance control system for gas turbine stationary blade

Seal plates for gas turbine stationary blade inner shrouds are made in a double cross type seal structure with a view to enhance sealing ability. Seal plates 1, 2 are mutually lapped and disposed in a turbine axial direction between inner shrouds 12 of stationary blades 11. End portion seal plate 5 is lapped on an end portion of the seal plate 2 and end portion seal plate 6 is lapped under an end portion of the seal plate 1. All these seal plates are fitted with their side end portions being inserted into groove 9a provided in the inner shrouds 12. Seal plates 3, 4 and seal plates 7, 8 engaged with the seal plates 3, 4 are also fitted between flange portions of the inner shrouds 12 with their side end portions being inserted into grooves 10a, 10b and grooves 9b, 9c, respectively. All the seal plates 1 to 8 are fitted between mutually opposing inner shrouds in turbine circumferential direction so as to cover cavity 24 between mutually adjacent shrouds, so that gaps between engaged portions of each seal plate and between the seal plates and seal ring support ring 13 are eliminated, thereby seal air 20 is prevented from leaking from the cavity 24.

Gas turbine stationary blade double cross type seal device

In order to realize a seal device of a gas turbine interstage portion which is excellent in a sealing ability during regular operation of the gas turbine, a gas turbine interstage portion seal device is constructed comprising a honeycomb seal (2) of a ring shape provided to an inner side of a turbine stationary blade inner ring (1) and a plurality of seal fins (5) of a ring shape provided to an outer side of a turbine disc seal arm portion (4). Also, an inner side surface of the honeycomb seal and outer peripheries of the plurality of seal fins, comprise large diameters and small diameters, and convex and concave portions formed thereby respectively are mated with each other.

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Takasago, Japan

Naoki Hagi