Patent ID: 6393822
Filing Date: 2002-05-28
Classification: F01K,F02C,F05D,Y02E

Abstract:
A cooling steam supply method of a combined cycle power generation plant, comprising a gas turbine plant, a steam turbine plant, a first superheater, an evaporator unit and an exhaust gas heat recovery boiler having a drum, which are operatively connected, in which a cooling steam is supplied from the drum of the exhaust gas heat recovery boiler to the gas turbine plant, said method comprising the steps of:supplying a steam remaining in the exhaust gas heat recovery boiler to the gas turbine plant during a hot start-up operation thereof; joining an exhaust steam generated from the steam turbine plant and a steam generated from the exhaust gas heat recovery boiler together after the steam turbine plant starts a ventilating operation; and supplying the joined steam to the gas turbine plant as a cooling steam; wherein said evaporator unit is divided into two evaporators and said drum is a high pressure drum; and wherein a steam remaining in the high pressure drum is supplied to the first superheater disposed at an intermediate portion between the divided two evaporators and a steam generated from the first superheater is supplied to the gas turbine plant as a cooling steam.