| 摘要 |
PURPOSE:To reduce the thermal stress of the rotor of a steam turbine, by opening a temperature decrease control valve depending on the deviation of the temperature of auxiliary steam as sealing steam from a temperature set depending on of the steam detected at the start of the turbine, in performing the temperature decrease control of the auxiliary steam as sealing steam. CONSTITUTION:In a combined-cycle power plant including a compressor 1, a combustor 2, a gas turbine 3, an electricity generator 4, a steam turbine 5 and an exhaust gas boiler 6, the temperature of auxiliary steam 7 is decreased by a temperature reducer 8 with the use of a condensate 11 and supplied as sealing steam to the steam turbine 5 through a sealing steam stop valve 32. At that time, a temperature reducer stop valve 10 is opened according to a temperature decrease control start instruction. After a time set by a timer, a temperature decrease control valve 9 is opened by PID control depending on the deviation of the auxiliary steam from an optimal decrease temperature set depending on the temperature of the firststage inside wall metal of the steam turbine 5. |
