Hitachi, Ltd.

Norihisa Wada

Haruo Urushidani

Tsuguo Hashimoto

A system configuration and operating method for a single shaft combined cycle plant includes a gas turbine, an exhaust heat recovery boiler for generating steam using exhaust heat discharged from the gas turbine, and a steam turbine driven by steam generated from the exhaust heat recovery boiler. Rotors of the gas turbine and rotors of the steam turbine are coupled. The steam turbine includes a high pressure turbine being supplied with and driven by high pressure steam generated at a superheater of the exhaust heat recovery boiler and a reheating turbine supplied with and driven by steam that passes through the high pressure turbine and is reheated by a reheater of the exhaust heat recovery boiler. The gas turbine operates independently and a regulated amount of cooling steam is supplied to the steam turbine in order to prevent superheating due to windage loss of the steam turbine rotating in an unventilated state. A bypass path is provided in parallel with the exhaust heat recovery boiler as a path through which cooling steam flows in order to further raise the cooling effect, and each turbine and a condenser are made to communicate so as to make pressure within the turbines low.

Single shaft combined cycle plant and operating thereof

Single shaft combined cycle plant and method for operating the same

In a system configuration and operating method for a single shaft combined cycle plant comprising a gas turbine (,), an exhaust heat recovery boiler (,) for generating steam using exhaust heat discharged from the gas turbine; and a steam turbine (,) driven by steam generated from the exhaust heat recovery boiler (,), rotors of the gas turbine (,) and rotors of the steam turbine (,) being coupled, and the steam turbine comprising a high pressure turbine (,) being supplied with and driven by high pressure steam generated at a superheater of the exhaust heat recovery boiler (,) and a reheating turbine (,) supplied with and driven by steam that passes through the high pressure turbine (,) and is reheated by a reheater of the exhaust heat recovery boiler (,), the gas turbine (,) operates independently, a regulated amount of cooling steam is supplied to the steam turbine (,) in order to prevent superheating due to windage loss of the steam turbine (,) rotating in an unventilated state, a bypass path (,) is provided in parallel with the exhaust heat recovery boiler (,) as a path through which cooling steam flows in order to further raise the cooling effect, and each turbine and a condenser (,) are made to communicate so as to make pressure within the turbines low.

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Hitachi, Japan

Norihisa Wada