Abstract: A gas turbine includes a compressor and a combustor having a first fuel supply system for supplying a first fuel and a second fuel supply system for supplying a second fuel lower in calorific value than the first fuel and burning compressed air and fuel supplied through switching the first fuel system and the second fuel system. A turbine is driven by combustion gas supplied from the combustor. An extraction system is provided for extracting part of the compressed air supplied from the compressor to the combustor. Control means are provided for controlling, so as to suppress a pressure change of the compressed air supplied to the combustor, by adjusting an opening of the control valve according to a calorific value of the second fuel when fuel supplied to the combustor is switched from the first fuel to the second fuel lower in calorific value than the first fuel.

Abstract: A gas turbine rotor warming structure comprises a tubular member having an axially extending central through hole and a plurality of fine holes formed in a side wall thereof. The tubular member is inserted in central holes of rotor disks each having blades so as to form an annular gap between the inner surfaces of the central holes and the outer surface of the tubular member. The plurality of fine holes of the tubular member are formed so as to face the inner peripheral surface of the central holse of the rotor disks, so that gas extracted from a compressor is injected into the annular gap through the fine holes and impinges on the inner peripheral surfaces of the rotor disks, whereby inner peripheral portions of the rotor disks are warmed at the time of starting of the gas turbine. The extracted compressor gas which has warmed the inner peripheral portions of the rotor disks passes between the disks and cools the turbine blades.

Abstract: A turbine rotor provided with a sealing member for preventing air leaks through a gap between the under side surface of a projection extending from one of discs of the rotor and the upper side surface of a outward end portion of the spacer interposed between the discs. The spacer is formed with an annular groove on the upper side surface of the outward end portion for receiving a sealing wire in its entirety. The sealing wire has its outer portion forced against the underside surface of the projection by centrifugal forces while its inner portion remains inside the groove during turbine operation, to thereby seal the gap to prevent leaks of air therethrough.