COMBINED PLANT AND CONTROL METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a combined plant capable of maintaining a stable output without reducing the efficiency upon a reduction or increase of a required output, and to provide a control method thereof.SOLUTION: The combined plant includes: a steam turbine 10 driven by steam generated using waste heat of a gas turbine 2; a steam drum 5 for generating steam using condensed water overheated by a waste heat recovery boiler 11 included in the gas turbine 2; a steam regulator valve 7 for adjusting supply of the steam generated by the steam drum 5 to the steam turbine 10; and a control device 30 for changing a combustion region of a combustor 9 included in the gas turbine 2 in response to the variation in the required output, and controlling the steam regulator valve 7 with a supply control signal for equalizing the total of a steam turbine output Sout and a gas turbine output Gout with the required output in response to the change of the combustion region. The control method of the plant is also provided.