COMBINED PLANT HAVING STEAM TURBINE AND GAS TURBINE CONNECTED BY SINGLE SHAFT

摘要

A combined plant including a gas turbine, a steam turbine and a waste heat recovery boiler using exhaust gases of the gas turbine as a heat source for producing steam serving as a drive source of the steam turbine further includes an ancillary steam source separate from and independent of the waste heat recovery boiler. At the time of startup of the plant, steam from the ancillary steam source is introduced into the steam turbine until the conditions for feeding air to the waste heat recovery boiler are set, to thereby avoid overheating of the steam turbine due to a windage loss.