Methods and systems of starting a gas turbine engine are provided. During startup, a fuel pressure associated with a primary fuel supply of the gas turbine engine is monitored. A low-pressure event for the primary fuel supply is detected when the fuel pressure falls below a predetermined threshold. Responsive to detecting the low pressure event, an electric backup boost pump is activated by an engine controller to provide fuel to the gas turbine engine.

A fuel system can include a total flow line configured to receive a total flow and a primary flow line connected to the total flow line. The primary flow line can be in fluid communication with one or more primary fuel nozzles of a nozzle assembly. The fuel system can include a secondary flow line connected to the total flow line in parallel with the primary flow line, the secondary flow line in fluid communication with a plurality of secondary flow nozzles of the nozzle assembly. The fuel system can include a flow split system configured to control a flow split between a primary flow of the primary flow line and a secondary flow of the secondary flow line.

A fuel system can include a total flow line configured to receive a total flow and a primary flow line connected to the total flow line. The primary flow line can be in fluid communication with one or more primary fuel nozzles of a nozzle assembly. The fuel system can include a secondary flow line connected to the total flow line in parallel with the primary flow line, the secondary flow line in fluid communication with a plurality of secondary flow nozzles of the nozzle assembly. The fuel system can include a flow split system configured to control a flow split between a primary flow of the primary flow line and a secondary flow of the secondary flow line.

A gas turbine engine includes a combustion section, the combustion section including a plurality of fuel nozzles. A fuel delivery system for the gas turbine engine includes a feed tube and a fuel manifold fluidly connected to the feed tube for receiving fuel from the feed tube. The fuel delivery system also includes a pigtail fuel line fluidly connected to the fuel manifold and configured to fluidly connect to a fuel nozzle of the plurality of fuel nozzles when the fuel delivery system is installed in the gas turbine engine. In order to reduce an amount of hydraulic instability of a fuel flow through the fuel delivery system, at least one of the fuel manifold or the pigtail fuel line includes a means for damping a hydraulic instability within the fuel delivery system.

A gas turbine engine includes a combustion section, the combustion section including a plurality of fuel nozzles. A fuel delivery system for the gas turbine engine includes a feed tube and a fuel manifold fluidly connected to the feed tube for receiving fuel from the feed tube. The fuel delivery system also includes a pigtail fuel line fluidly connected to the fuel manifold and configured to fluidly connect to a fuel nozzle of the plurality of fuel nozzles when the fuel delivery system is installed in the gas turbine engine. In order to reduce an amount of hydraulic instability of a fuel flow through the fuel delivery system, at least one of the fuel manifold or the pigtail fuel line includes a means for damping a hydraulic instability within the fuel delivery system.

A system includes a flow inlet conduit. A primary conduit branches from the flow inlet conduit for delivering flow to a set of primary nozzles. An equalization bypass valve (EBV) connects between the flow inlet conduit and a secondary conduit for delivering flow to a set of secondary nozzles. The EBV is connected to be controlled to apportion flow from the flow inlet conduit to the secondary conduit. A secondary equalization valve (SEV) connects between the flow inlet conduit and the secondary conduit. The SEV is connected to be controlled by drain pressure (PD) to apportion flow from the flow inlet conduit to the secondary conduit.

A loading/unloading method for a gas turbine system is disclosed. The gas turbine system includes a combustion section featuring a primary combustion stage with a first plurality of fuel nozzles and a downstream, secondary combustion stage with a second plurality of fuel nozzles. For loading, the method progresses through each of a plurality of progressive combustion modes that sequentially activate a higher number of at least one of the first or second plurality of fuel nozzles; and for unloading, the method progresses through each of a plurality of progressive combustion modes that sequentially activate a lower number of at least one of the first or second plurality of fuel nozzles. During each combustion mode, regardless of whether loading or unloading, a primary combustion stage exit temperature of a combustion gas flow is controlled to be within a predefined target range corresponding to the respective combustion mode.

A loading/unloading method for a gas turbine system is disclosed. The gas turbine system includes a combustion section featuring a primary combustion stage with a first plurality of fuel nozzles and a downstream, secondary combustion stage with a second plurality of fuel nozzles. For loading, the method progresses through each of a plurality of progressive combustion modes that sequentially activate a higher number of at least one of the first or second plurality of fuel nozzles; and for unloading, the method progresses through each of a plurality of progressive combustion modes that sequentially activate a lower number of at least one of the first or second plurality of fuel nozzles. During each combustion mode, regardless of whether loading or unloading, a primary combustion stage exit temperature of a combustion gas flow is controlled to be within a predefined target range corresponding to the respective combustion mode.

A fuel conditioning and control system provides dynamic control and steady state operations of a gas turbine provided fueled by supercritical liquefied petroleum gas (LPG). The fuel conditioning and control system comprises a storage for LPG fuel; a fuel delivery sub-system connecting the storage to turbomachinery; and a control system. The gas turbine includes a gas turbine core control that provides at least one operational data of the gas turbine to the control system. The fuel delivery sub-system includes at least one sensor for sensing at least one property of the LPG fuel in the fuel delivery sub-system, where the at least one sensor providing data on the at least one property of the LPG fuel to the control system. The control system analyzes the data on the at least one property of the LPG fuel and at least one operational data of the gas turbine for dynamic control of LPG fuel to the gas turbine under dynamic and steady state conditions.

The method allows to control a test apparatus for a gas turbine engine; WI values of one or more tentative fuel gas mixtures are predicted by calculations and the predicted WI values are used for setting the composition of a fuel gas mixture to be supplied to a combustor of a gas turbine engine under test. The test apparatus comprises: a first supply flow line for fuel gas; a second supply flow line for inert gas; a mixer with a first inlet for fuel gas and a second inlet for inert gas, and with an outlet for supplying the mixture of fuel gas and inert gas to the combustor; a set of meters; and a flow control device for the inert gas.