Methods and systems are provided for automatically tuning a combustor of a gas turbine engine during a transient period, such as when a state of the gas turbine engine is changing. Once it has been determined whether the state of the gas turbine engine is changing, it is then determined whether a lean blowout is imminent, which is based conditions being monitored. A stability bias is applied to the system if either the state is changing or if lean blowout is imminent until the lean blowout is no longer determined to be imminent. The stability bias monitors operating conditions of the gas turbine engine and determines when one of the operating conditions has overcome a threshold value. Once a threshold value is overcome, a fuel flow fraction is adjusted by a predefined increment. The application of the stability bias is gradually terminated once it is determined that the lean blowout is no longer imminent.

An auto-tune controller and tuning process implemented thereby for measuring and tuning the combustion dynamics and emissions of a GT engine, relative to predetermined upper limits, are provided. Initially, the tuning process includes monitoring the combustion dynamics of a plurality of combustors and emissions for a plurality of conditions. Upon determination that one or more of the conditions exceeds a predetermined upper limit, a fuel flow split to a fuel circuit on all of the combustors on the engine is adjusted by a predetermined amount. The control system continues to monitor the combustion dynamics and to recursively adjust the fuel flow split by the predetermined amount until the combustion dynamics and/or emissions are operating within a prescribed range of the GT engine. Additionally, a method of automated extended turndown of a GT engine to find a minimum load is provided.

A fuel manifold apparatus includes an annular array of fuel nozzles interconnected by a plurality of manifold tubes, wherein each manifold tube includes at least two fuel passages integrally formed therein, the fuel passages being configured for conduction heat transfer therebetween.

A fuel conditioning system includes a heater for selectively adjusting an operating temperature of the fuel and a controller communicatively coupled to the heater. The controller configured to determine a dew point temperature of the fuel and maintain the operating temperature of the fuel at least at the determined dew point temperature of the fuel.

A method of controlling a combustor of a gas turbine engine, the method comprising the steps supplying a total fuel quantity to the combustor dependent on a load of the gas turbine engine, the total fuel quantity is split into a pilot fuel quantity and a main fuel quantity via a scheduled pilot fuel split, the pilot fuel split is the percentage of the pilot fuel quantity of the total fuel quantity, monitoring combustion instability, applying a steady state active pilot split offset to the scheduled pilot fuel split when a predetermined temperature of the combustor is exceeded and/or a predetermined value of combustion instability is exceeded to create a steady state pilot fuel split, monitoring a condition of the gas turbine engine that influences an air/fuel ratio in the combustor, disabling the steady state active pilot split offset when the condition of the gas turbine engine is indicative of a transient condition and when a threshold value of combustion instability is exceeded, and applying a transient active pilot split offset to the steady state pilot fuel split while maintaining the total fuel quantity being supplied at any point in time, the transient active pilot split offset and the steady state active pilot split offset result in a total split offset, the total split offset being greater than the steady state active pilot split offset and the rate of change of the transient active pilot split offset is faster than the rate of change of the steady state active pilot split offset.

A fuel conditioning system includes a heater for selectively adjusting an operating temperature of the fuel and a controller communicatively coupled to the heater. The controller configured to determine a dew point temperature of the fuel and maintain the operating temperature of the fuel at least at the determined dew point temperature of the fuel.

A gas turbine engine includes a staged combustion system having pilot fuel injectors and main fuel injectors. A fuel delivery regulator controls delivery of fuel to the pilot and main fuel injectors, receives fuel from a first fuel source containing a first fuel having a first fuel characteristic and a second fuel source containing a second fuel having a second fuel characteristic. In a transition range of operation between the pilot-only and the pilot-and-main ranges of operation, fuel is delivered to both the pilot and main fuel injectors at a transition staging ratio different from the pilot-and-main staging ratio. The fuel delivery regulator delivers fuel to one or both the pilot and main fuel injectors during the transition range of operation having a different fuel characteristic from fuel delivered to one or both the pilot and main fuel injectors during at least part of the pilot-and-main range of operation.

A delay time calculation method includes: a step of calculating a plurality of segment movement delay times respectively indicating times required for the fuel gas to pass through a plurality of segments; a step of calculating a total movement delay time which is a time required for the fuel gas to move through the fuel line from the measurement point to the supply target device, by adding up the plurality of segment movement delay times; and a step of acquiring the delay time based on the total movement delay time. The step of calculating the plurality of segment movement delay times includes acquiring the segment movement delay time based on a correlation between the segment movement delay time acquired in advance and a fuel flow rate supplied to the supply target device, for each of the plurality of segments.

A combustor for a turbine engine includes a combustion chamber including an outer liner and an inner liner, and an annular dome. A plurality of first mixing assemblies includes a pilot mixer and a first main mixer, the first mixing assemblies disposed through the annular dome. The pilot mixer injects a pilot mixer fuel-air mixture axially into a first combustion zone, and the first main mixer injects a first main mixer fuel-air mixture radially into the first combustion zone. A plurality of second mixing assemblies includes a second main mixer, the second mixing assemblies being axially aft of the plurality of first mixing assemblies. The second main mixer injects a second main mixer fuel-air mixture radially into a second combustion zone that is axially aft of, and separate from, the first combustion zone.

A turbomachine injection manifold assembly including a main circuit for feeding fuel to sets of injectors, and an auxiliary circuit for feeding fuel to a set of injectors. The manifold assembly also includes a double coupling presenting a first endpiece receiving one end of a transfer tube of the main circuit, a second endpiece receiving one end of a transfer tube of the auxiliary circuit, and a mounting surface with a first orifice in fluid flow communication with the first endpiece and a second orifice in fluid flow communication with the second endpiece, the mounting surface of the double coupling being suitable for connecting the double coupling to an injector of said first set of injectors.