Abstract: A means detecting the flow of the steam at the gateway of the steam cooling system is provided, and the timing of the finish of the warm-up process of the steam cooling system at start-up is decided by the difference of the flow of the steam at the gateway. In case of the difference between the flow of the steam at the inlet and the flow of the steam at the outlet is below a permitted value, it is considered that residual air and drainage have been purged, the warming-up is finished, and the step for starting the gas turbine can be performed.

Abstract: A gas turbine steam cooled system has a high temperature portion 8 outlet steam temperature maintained to a predetermined value without a cooling steam pressure becoming lower than the pressure in the gas turbine cylinder. Steam coming from an intermediate pressure superheater 10 of a waste heat recovery boiler 2 is led into the high temperature portion 8 of the gas turbine for cooling thereof. The temperature of the cooling steam at the outlet of the high temperature portion 8 is detected by a high temperature portion outlet steam temperature detector 15, and a signal thereof is sent a lower value selector 19 via a temperature controller 11. Pressure in the gas turbine cylinder is detected by a gas turbine cylinder pressure detector 17, and pressure of the cooling steam at the high temperature portion 8 outlet is detected by a high temperature portion outlet steam pressure detector 16. A differential signal thereof is sent to a pressure controller 18.

Abstract: A combined cycle power plant having a gas turbine plant and a steam turbine plant combined together is disclosed. Steam is used for cooling a high-temperature portion (5) to be cooled around the combustor (4) of the gas turbine (2). The power plant has an air duct (9), connected to a steam path (7) for supplying steam for cooling the high-temperature portion (5), for cooling this portion using air if the steam for cooling is insufficient, typically when the plant is activated or stopped, and the air duct includes a device for boosting the air to have a pressure higher than that inside a combustor (4) of the power plant. Accordingly, the combustor and attached piping arrangement can be protected from burning and the power plant can be safely and reliably operated for a long time.

Abstract: A means detecting the flow of the steam at the gateway of the steam cooling system is provided, and the timing of the finish of the warm-up process of the steam cooling system at start-up is decided by the difference of the flow of the steam at the gateway. In case of the difference between the flow of the steam at the inlet and the flow of the steam at the outlet, of the steam cooling system, is below a permitted value, it is considered that residual air and drainage are not remained between the inlet and the outlet and the warming-up is finished, and running to the step for starting the gas turbine can be performed.

Abstract: A combined cycle power plant having a gas turbine plant and a steam turbine plant combined together is disclosed. Steam is used for cooling a high-temperature portion (5) to be cooled around the combustor (4) of the gas turbine (2). The power plant has an air duct (9), connected to a steam path (7) for supplying steam for cooling the high-temperature portion (5), for cooling this portion using air if the steam for cooling is insufficient, typically when the plant is activated or stopped, and the air duct includes a device for boosting the air to have a pressure higher than that inside a combustor (4) of the power plant. Accordingly, the combustor and attached piping arrangement can be protected from burning and the power plant can be safely and reliably operated for a long time.

Abstract: The present invention provides a combined cycle electric power generating plant that effectively reduces the noise produced by the exhaust of steam in the warm-up process or the like. This plant has a duct which drives the steam used for warming a steam cooling system which cools the high temperature parts which are cooled of the gas turbine at the start of the operation to an exhaust duct of the gas turbine. The steam used for warming a steam cooling system is directed to the exhaust duct of the gas turbine, and the noise which is produced by the exhaust of the steam for warming is silenced by the exhaust duct of the gas turbine.