Abstract: To improve the thermal efficiency when an exhaust heat recovery type combined cycle plant having a gas turbine and a steam turbine in combination is operated at a partial load, the gas turbine exhaust is recirculated and returned to the compressor, and the combustion temperature is prevented from being lowered at the partial load. Preferably, the temperature is maintained constant. In this way, the thermal efficiency during operation at partial load can be improved.

Abstract: To improve the thermal efficiency when an exhaust heat recovery type combined cycle plant having a gas turbine and a steam turbine in combination is operated at a partial load, the gas turbine exhaust is recirculated and returned to the compressor, and the combustion temperature is prevented from being lowered at the partial load. Preferably, the temperature is maintained constant. In this way, the thermal efficiency during operation at partial load can be improved.

Abstract: To improve the thermal efficiency when an exhaust heat recovery type combined cycle plant having a gas turbine and a steam turbine in combination is operated at a partial load, the gas turbine exhaust is recirculated and returned to the compressor, and the combustion temperature is prevented from being lowered at the partial load. Preferably, the temperature is maintained constant. In this way, the thermal efficiency during operation at partial load can be improved.

Abstract: To provide a combined-cycle power generation plant heat exchanged effectively in an exhaust heat, the recovery boiler is increased by suppressing on reducing the swirl present in the exhaust gas of a gas turbine. That is, a plurality of stationary blades 10 are arranged on the surface of a rear inner barrel in the circumferential direction of the rear inner barrel to partition an annular channel formed between a casing and the rear inner barrel. Thereby, it is possible to uniform the flow of exhaust gas with a low pressure drop.

Abstract: A fuel supply amount is controlled while the load of a gas turbine is changed so that the fuel supply amount is shifted to a fuel supply amount in accordance with the changed load. A fuel supply control valve is operated at high speed during an initial stage and operated at a lower speed as the fuel supply amount necessary for the changed load is reached. Therefore flameout of a combustor is prevented without increasing the number of revolutions of the gas turbine over a certain upper limit.

Abstract: A combustor includes a first premixture supply device provided in a central portion of a combustion chamber disposed generally concentric with a combustion cylinder, and a second premixture supply means provided adjacent to an outer periphery of the first premixture supply device. The first premixture supply device is operable when the combustor is under a high load, and the second premixture supply device is operable when the combustor is under a low load. A method of operating a combustor is also proposed wherein the combustor comprises a combustion cylinder having a combustion chamber therein and a premixture supply device provided on one side of the combustion cylinder for supplying a combustible mixture to the combustion chamber. The premixture supply device comprising at least two inner and outer premixture supply devices.

Abstract: A gas turbine includes a cooling air supply device for supplying compressed cooling air to moving blades, and a heat exchanger provided in the cooling air supply device for cooling the compressed cooling air. Compressed air withdrawn at an intermediate-stage portion of a compressor is used as a cooling medium for the heat exchanger. With this construction, the moving blades can be sufficiently cooled without the use of any special cooling medium.

Abstract: A gas turbine combustor and a method of operating the gas turbine combustor, with the gas turbine combustor comprising a combustion sleeve, a combustion sub-chamber disposed at an upstream side of the combustion sleeve and having an air and fuel supply system, and a combustion main chamber disposed on a downstream side of the sub-chamber and having an air and fuel supply system. The combustion sub-chamber and combustion main chamber are formed in such a manner that the start-up of the gas turbine is effected by the hot combustion gas generated in the sub-chamber. The combustion sub-chamber is provided with an inner sleeve protruding from a side wall of the sub-chamber such that a tip of the inner sleeve is located in the vicinity of a downstream end of the sub-chamber, and a fuel nozzle is provided in a tip of the inner sleeve for increasing the fuel-to-air ratio during an initiating period of an increase in the gas turbine rotation speed.

Abstract: A method for detecting combustion conditions in a plurality of combustors in a gas-turbine apparatus which includes the combustors and a gas turbine driven by combustion gas from the combustors, comprises a step for measuring concentration of unburnt component in the combustion gas by means of a plurality of sensors disposed on the downstream side of the gas turbine, a step for obtaining a distribution pattern of the measured concentration, and a step for investigating the distribution pattern to detect combustion conditions in the combustors.

Abstract: A gas turbine combustor comprising a head combustion chamber and a rear combustion chamber connected to a downstream side of the head combustion chamber, a first stage burner for premixing first stage fuel and air and supplying the resultant fuel and air premixture into the head combustion chamber to effect first stage premix combution, a second stage burner for premixing second stage fuel and air and the resultant fuel and air premixture into the rear combustion chamber to effect premix combustion in addition to the first stage premix combustion, and a device for regulating flow rates of combustion air to be premixed with first and second stage fuel. The combustor is further provided with a pilot burner in the head combustion chamber to form pilot flame and stabilize the first stage premix combustion.

Abstract: A device for detecting combustion conditions in a plurality of combustors in a gas-turbine apparatus which includes the combustors and a gas turbine driven by combustion gas from the combustors, comprises a plurality of sensors for measuring concentration of unburnt component in the combustion gas, which is disposed on the downstream side of the gas turbine, a unit for obtaining a distribution pattern of the measured concentration and for investigating the obtained distribution pattern to detect combustion conditions in the combustors.

Abstract: A fuel-air premixing device of a gas turbine has a double-cylinder structure composed of an inner cylinder and an outer cylinder defining therebetween flow passages such that a fuel is supplied into air flowing through the passages so that a pre-mixture of the fuel and air is formed and discharged. The premixing device further has a plurality of radially spaced fuel nozzles capable of supplying the fuel into the passages, and fuel supply rate regulator valves for independently controlling the rates of supply of the fuel from the radially spaced nozzles.

Abstract: A combined gas turbine plant comprises an air compressor, a combustor including a combustion chamber, a gas turbine, a steam turbine, and an exhaust heat recovery device having a denitration device and arranged at a location through which an exhaust gas passage for leading exhaust gas from the gas turbine to the atmosphere extends. An air extraction pipe equipped with a valve is provided for extracting a part of the air from the air compressor to prevent surging of the air compressor during starting of the plant, and another air extraction pipe equipped with a valve is provided for extracting a part of the air from an air passage extending from the compressor to the combustion chamber to improve stability of a flame and combustibility in the combustion chamber during the plant starting. The extraction pipes extend to and hence lead the extracted air into a portion of the exhaust gas passage located downstream of the denitration device.

Abstract: A combustor of two-stage combustion type in which fuel is supplied only from primary fuel nozzles for combustion only in primary combustion chamber under the operating condition where gas turbine load is low, and premixed mixture is supplied into a secondary combustion chamber provided on the downstream side of the primary combustion chamber for combustion in both the primary and secondary combustion chambers under the operating condition where the load is high. An air-bleed passageway opens on a downstream side of air holes for intaking secondary combustion air to be mixed with secondary fuel and communicates with the outside of the combustor. The air-bleed passageway is provided with a regulating valve and the secondary combustion air is bled at the minimum point of the load where the secondary fuel is supplied so that the fuel to air ratio of secondary premixed mixture may not be excessively lean, thereby reducing the production of non-burned components.