US Patent 11629618 Combined cycle power plant having serial heat exchangers

A gas turbine system includes a compressor section, a turbine section, a combustor section. The combustor section is in fluid communication with a fuel supply via a fuel supply line. The water circuit includes a first water line extending between a first feed water supply line and a return water line. The gas turbine system further includes an extraction-air line that extends between an inlet port on the compressor section and an outlet port on the turbine section. A first heat exchanger thermally couples the first water line to the extraction-air line for transferring heat from a flow of extraction-air within the extraction-air line to a flow of water within the water circuit. A second heat exchanger thermally couples the first water line to the fuel supply line for transferring heat from the flow of water within the water circuit to a flow of fuel within the fuel supply line.