System and method for heat recovery in a combined cycle power plant

In a combined cycle power plant having a gas turbine, a steam turbine, and a heat recovery steam generator, a method of recovering heat from the exhaust gas of said gas turbine in said heat recovery steam generator comprising the steps of:

• (a) supplying water, splitting said water supplied into first and second streams, directing said first stream to a vessel, directing said second stream to a feedwater heater, transferring heat from said exhaust gas to said second stream in said feedwater heater, directing said second stream after said heating in said feedwater heater to said vessel, said heated water providing a first source of heat input to said vessel, mixing said first and second streams in said vessel, thereby producing heated feedwater;
• (b) regulating the relative quantities of said first and second streams of said water supplied so as to maintain a predetermined pressure in said vessel;
• and
• (c) venting from said vessel gases released from said heated feedwater mixture.