Combined Cycle Plant

Abstract

A combined cycle plant including a gas turbine, a heat recovery boiler for generating steam using exhaust heat of the gas turbine, and a steam turbine for feeding the steam generated by the heat recovery boiler from the heat recovery boiler through a steam system, characterized in that, the steam system is disposed so as to branch to a first steam system for introducing the steam to a first stage entrance of the steam turbine and a second steam system for introducing the steam to a stage entrance on a downstream side of the first stage of the steam turbine, and a flow rate of the steam fed to the steam turbine via the first steam system and the second steam system is adjusted on the basis of a steam flow rate generated by the heat recovery boiler.

1 . A combined cycle plant including a gas turbine, a heat recovery boiler for generating steam using exhaust heat of the gas turbine, and a steam turbine for feeding the steam generated by the heat recovery boiler from the heat recovery boiler through a steam system,
 characterized in that,   the steam system is disposed so as to branch to a first steam system for introducing the steam to a first stage entrance of the steam turbine and a second steam system for introducing the steam to a stage entrance on a downstream side of the first stage of the steam turbine, and   a flow rate of she steam fed to the steam turbine via the first steam system and the second steam system is adjusted on the basis of a steam flow rate generated by the heat recovery boiler.   
     
     
         2 . The combined cycle plant according to  claim 1 , wherein:
 the steam turbine is comprising a high-pressure turbine with high-pressure steam fed and an intermediate-low pressure turbine with low-pressure steam fed;   the first steam system is disposed to feed a part of the steam generated by the heat recovery boiler to the first stage entrance of the high-pressure turbine of the steam turbine;   the second steam system is disposed to feed another part of the steam generated by the heat recovery boiler to the stage entrance on the downstream side of the first stage of the high-pressure turbine of the steam turbine;   a first steam valve for adjusting a feed amount of the steam fed to the first stage entrance of the high-pressure turbine is installed in the first steam system;   a second steam valve for adjusting a feed amount of the steam fed to the stage entrance on the downstream side of the first stage of the high-pressure turbine is installed in the second steam system; and   a control unit is installed to operate the first steam valve and the second steam valve on the basis of the steam flow rate generated by the heat recovery boiler so that the steam flow rate fed to the first stage entrance of the high-pressure turbine of the steam turbine and the stage entrance on the downstream side of the first stage is adjusted.   
     
     
         3 . The combined cycle plant according to  claim 2 , wherein:
 a pressure detector for measuring pressure of the steam generated by the heat recovery boiler, which is a detection means for detecting the steam flow rate generated by the heat recovery boiler, is installed in the steam system for feeding from the heat recovery boiler to the steam turbine, and   the control unit operates opening angles of the first steam valve and the second steam valve and adjusts the flow rate of the steam fed to the steam turbine via the first steam system and the second steam system on the basis of a measured pressure value of the steam generated by the heat recovery boiler, which is measured by the pressure detector.