H2 power plant with o2 integration

A method of generating power with a combined cycle power plant, the method comprising:

• operating a gas turbine engine to combust a fuel to produce exhaust gas;
• rotating a turbine with the exhaust gas to rotate a shaft;
• generating electricity with a generator driven by the shaft;
• transferring heat from the exhaust gas to produce heated fluid in a heat recovery steam generator to rotate a steam turbine;
• generating electricity with a generator driven by the steam turbine;
• generating hydrogen gas and oxygen gas with an electrolyzer from a water input and an electrical input;
• routing the hydrogen gas to the gas turbine engine for combustion;
• routing the oxygen gas and the heated fluid through a heat exchanger;
• heating the oxygen gas in the heat exchanger;
• and
• routing the heated oxygen gas to the gas turbine engine for blending with combustion air.

A turbine cooling air system comprising:

• a combined turbine cooling air cooler comprising:
• a first flow path for receiving bleed air from a compressor of a gas turbine engine;
• a second flow path in thermal communication with the first flow path, the second flow path configured for receiving oxygen gas from an oxygen source to cool the bleed air;
• and
• a third flow path in thermal communication with the first flow path, the third flow path configured for receiving feedwater from a heat recovery steam generator to cool the bleed air;
• a bypass line configured to route oxygen gas from the oxygen source directly to the gas turbine engine;
• and
• a first bleed air output of the combined turbine cooling air cooler configured to route at least a portion of the bleed air to a turbine of the gas turbine engine.