GAS TURBINE, COMBINED CYCLE PLANT, AND METHOD OF STARTING GAS TURBINE

摘要

PROBLEM TO BE SOLVED: To secure safety and improve performance in a gas turbine, a combined cycle plant and a method of starting the gas turbine, by making a clearance between a turbine casing side and rotor blades a proper amount.SOLUTION: A gas turbine is provided with: an air cooler 31 supplying compressed air, that is cooled by heat-exchanging compressed air bled from a compressor 21, to a cooling system of a rotor system in a turbine 23; an air cooler bypass line 34 bypassing the compressed air introduced into the air cooler 31; a motor-operated valve 35 provided in the air cooler bypass line 34; and a control part 101 controlling open and close of the motor-operated valve 35 to set a valve opening of the motor-operated valve 35 equal to or smaller than a low level opening during starting of the gas turbine 20 and to set the valve opening of the motor-operated valve 35 larger than the low level opening after a load on the gas turbine 20 increases.SELECTED DRAWING: Figure 2