Gas turbine water injection for emissions reduction

A method for delivering water for injection into a combustor of a gas turbine engine, comprising:

• operating a centrifugal pump having an inlet connected to a water source and a discharge delivering pressurized water to a water supply line,
• wherein a metering valve is connected to the water supply line downstream of the discharge of the centrifugal pump,
• wherein the water supply line is connected to an injector nozzle downstream of the metering valve, and
• controlling the metering valve to regulate a flow rate of water in the water supply line, to thereby meter an amount of water supplied to the injector nozzle for injection into the combustor.

A computer-implemented method for controlling an amount of water injected into a combustor of a gas turbine engine for reducing emissions produced by the gas turbine engine, comprising:

• determining a change in engine operating state,
• adjusting a fuel demand of the combustor responsive to the change in engine operating state,
• dynamically determining a flow rate of water to be injected into the combustor responsive to the change in engine operating state and the adjustment of the fuel demand,
• generating a control signal to actuate a metering valve of a water delivery system to achieve the determined flow rate of water injected into the combustor,
• wherein the water delivery system comprises a centrifugal pump and said metering valve connected to a discharge of the centrifugal pump for delivering metered pressurized water to an injector nozzle.