A turbomachine and method for operating a turbomachine comprising a first rotatable component and a second rotatable component each defining a rotatable speed mechanically independent of one another, and an electric machine electrically coupled to the first rotatable component and the second rotatable component such that a load level relative to the first rotatable component and the second rotatable component is adjustable is generally provided. The method includes adjusting a first load at a first rotor assembly of the electric machine electrically coupled to the first rotatable component such that a first speed of the first rotatable component is increased or decreased based on an engine condition and the first load; adjusting a second load at a second rotor assembly of the electric machine electrically coupled to the second rotatable component such that a second speed of the second rotatable component is decreased or increased based on the engine condition and the second load; and transferring electrical energy generated from at least one of the first rotatable component or the second rotatable component.

A fuel system including a fuel tank, a first pump fluidly coupled to the fuel tank configured for distributing fuel from the fuel tank throughout the fuel system, and a second pump fluidly coupled to the first pump by a pressure regulating valve and configured for driving fuel to an engine.

A combustion chamber system has pilot and main fuel manifolds, and pilot and main fuel nozzles. Each pilot nozzle is connected to the pilot manifold. Each main nozzle is connected to the main manifold. A greater total amount of fuel is supplied to the pilot nozzles than to the main nozzles. A greater amount of fuel is supplied to pilot nozzles at, or in, a first region of the combustion chamber than to pilot fuel nozzles at, or in, a second region. A greater amount of fuel is supplied to the main nozzles at, or in, the first region than to the main nozzles at, or in, the second to improve combustion efficiency, weak extinction and relight of the combustion chamber in a first mode of operation. A greater total amount of fuel is supplied to the main nozzles than to the pilot nozzles in a second mode of operation.

A combustion chamber system has pilot and main fuel manifolds, and pilot and main fuel nozzles. Each pilot nozzle is connected to the pilot manifold. Each main nozzle is connected to the main manifold. A greater total amount of fuel is supplied to the pilot nozzles than to the main nozzles. A greater amount of fuel is supplied to pilot nozzles at, or in, a first region of the combustion chamber than to pilot fuel nozzles at, or in, a second region. A greater amount of fuel is supplied to the main nozzles at, or in, the first region than to the main nozzles at, or in, the second to improve combustion efficiency, weak extinction and relight of the combustion chamber in a first mode of operation. A greater total amount of fuel is supplied to the main nozzles than to the pilot nozzles in a second mode of operation.

A fuel metering system for a combustion section of a turbo machine is provided. The turbo machine includes a main fuel line configured to provide a flow of fuel and a zone fuel line split from the main fuel line through which at least a portion of the flow of fuel is provided. A fuel valve is disposed at the zone fuel line and is configured to obtain and receive a present fuel valve area value and a present valve position value. A first pressure sensor is disposed upstream of the fuel valve, in which the first pressure sensor is configured to obtain a first pressure value. A second pressure sensor is disposed downstream of the fuel valve, in which the second pressure sensor is configured to obtain a second pressure value. A flow meter is disposed downstream of the fuel valve. A controller is configured to perform operations, in which the operations include determining a demanded fuel valve actuator position based at least on an estimated fuel valve actuator position and a demanded fuel flow; comparing the demanded fuel flow and a present fuel flow; determining an actual fuel valve actuator position based at least on the demanded fuel valve actuator position and the compared demanded fuel flow and present fuel flow; and generating an valve effective area at the fuel valve based at least on the actual fuel valve actuator position.

A fuel metering system for a combustion section of a turbo machine is provided. The turbo machine includes a main fuel line configured to provide a flow of fuel and a zone fuel line split from the main fuel line through which at least a portion of the flow of fuel is provided. A fuel valve is disposed at the zone fuel line and is configured to obtain and receive a present fuel valve area value and a present valve position value. A first pressure sensor is disposed upstream of the fuel valve, in which the first pressure sensor is configured to obtain a first pressure value. A second pressure sensor is disposed downstream of the fuel valve, in which the second pressure sensor is configured to obtain a second pressure value. A flow meter is disposed downstream of the fuel valve. A controller is configured to perform operations, in which the operations include determining a demanded fuel valve actuator position based at least on an estimated fuel valve actuator position and a demanded fuel flow; comparing the demanded fuel flow and a present fuel flow; determining an actual fuel valve actuator position based at least on the demanded fuel valve actuator position and the compared demanded fuel flow and present fuel flow; and generating an valve effective area at the fuel valve based at least on the actual fuel valve actuator position.

A method and system for cleaning a fuel nozzle during engine operation is provided. Operations include operating the compressor section to provide the flow of oxidizer at a first oxidizer flow condition to the combustion chamber, wherein the first oxidizer flow condition comprises an environmental parameter; operating the fuel system at a first fuel flow condition to produce a fuel-oxidizer ratio at the combustion chamber; comparing the environmental parameter to a first environmental parameter threshold; and transitioning the fuel system to a second fuel flow condition corresponding to a cleaning condition at the fuel nozzle if the environmental parameter is equal to or greater than the first environmental threshold.

A method and system for cleaning a fuel nozzle during engine operation is provided. Operations include operating the compressor section to provide the flow of oxidizer at a first oxidizer flow condition to the combustion chamber, wherein the first oxidizer flow condition comprises an environmental parameter; operating the fuel system at a first fuel flow condition to produce a fuel-oxidizer ratio at the combustion chamber; comparing the environmental parameter to a first environmental parameter threshold; and transitioning the fuel system to a second fuel flow condition corresponding to a cleaning condition at the fuel nozzle if the environmental parameter is equal to or greater than the first environmental threshold.

The method can include, in sequence: varying the flow rate of fuel from the first flow rate to a second flow rate, thereby varying the rotor speed from a first speed to a second speed, varying the flow rate of fuel back to the first flow rate, and rotating the rotor at the first speed for a given period of time.

The method can include, in sequence: varying the flow rate of fuel from the first flow rate to a second flow rate, thereby varying the rotor speed from a first speed to a second speed, varying the flow rate of fuel back to the first flow rate, and rotating the rotor at the first speed for a given period of time.