A fuel injector for a gas turbine engine includes a feed arm defining a conduit extending between an inlet end and an outlet end and a plunger. The plunger is disposed within the conduit and is movable between a plunger first position and a plunger second position. A flow area defined between the plunger and the feed arm is smaller in the plunger first position than in the plunger second position to bias fuel flow through the fuel injector. Fuel systems, gas turbine engines, and methods of controlling fuel flow in gas turbine engine fuel systems are also described.

A liquid fuel portable heater (100) comprises: a combustion chamber (101) having a fuel inlet with a nebuliser (13); an electric pump (10) having an inlet (11) for suctioning said liquid fuel from a tank (6), and an outlet (12) connected to said nebuliser (13); a control unit (20) configured so that, when the heater (100) is turned on, said control unit (20) supplies the electric pump with a sequence of pulses (115, 115) with a non-zero voltage, and pause intervals (116) with a substantially zero voltage alternating with said pulses, wherein the average duration of the pulses (115, 115) is less than the average duration of the pause intervals (116). In addition, a method for controlling an electric power supply of a fuel electric pump (10) of a liquid fuel portable heater by means of an electric control unit (20) configured to control said electric power supply, comprising a step of electrically supplying said pump, once the heater is turned on, with a sequence of pulses (115, 115) with a non-zero voltage, and pause intervals (116) with a substantially zero voltage alternating with said pulses, wherein the average duration of the pulses (115, 115) is less than the average duration of the pause intervals (116).

A liquid fuel portable heater (100) comprises: a combustion chamber (101) having a fuel inlet with a nebuliser (13); an electric pump (10) having an inlet (11) for suctioning said liquid fuel from a tank (6), and an outlet (12) connected to said nebuliser (13); a control unit (20) configured so that, when the heater (100) is turned on, said control unit (20) supplies the electric pump with a sequence of pulses (115, 115) with a non-zero voltage, and pause intervals (116) with a substantially zero voltage alternating with said pulses, wherein the average duration of the pulses (115, 115) is less than the average duration of the pause intervals (116). In addition, a method for controlling an electric power supply of a fuel electric pump (10) of a liquid fuel portable heater by means of an electric control unit (20) configured to control said electric power supply, comprising a step of electrically supplying said pump, once the heater is turned on, with a sequence of pulses (115, 115) with a non-zero voltage, and pause intervals (116) with a substantially zero voltage alternating with said pulses, wherein the average duration of the pulses (115, 115) is less than the average duration of the pause intervals (116).

A system includes an injector including a scheduling valve assembly and a nozzle in fluid communication with the scheduling valve assembly. The injector includes two fluid circuits, a primary circuit and a secondary circuit, between the inlet of the injector and two respective outlets for staged flow output. A cooling circuit is in fluid communication with the inlet of the injector. The cooling circuit is in thermal communication with the secondary circuit for selectively cooling the secondary circuit at low flow and no flow conditions of the secondary circuit. A separate valve is connected in fluid communication in the cooling circuit for controlling flow through the cooling circuit. The separate valve is configured for active control regardless of pressure at the inlet of the injector. The scheduling valve assembly is configured for passive control of the primary and secondary circuits based on pressure at the inlet of the injector.

A combustion chamber assembly of a gas turbine, for combusting a fuel in the presence of combustion air, is configured as a dual-fuel combustion chamber assembly. In a gas fuel operating mode a mixture of a gaseous fuel and combustion air is supplied to the combustion chamber via a swirl body. In a liquid fuel operating mode liquid fuel is fed to the combustion chamber via a fuel lance and combustion air is fed to the combustion chamber via the swirl body. The fuel lance is surrounded by an adjoining lance cap to form a radial clearance therebetween such that the combustion chamber is feedable with combustion air via the radial clearance, bypassing the swirl body.

The subject matter of this specification can be embodied in, among other things, a fluid flow trim apparatus includes an outer housing defining a cavity having an interior surface and an end wall having an orifice therethrough, a valve body comprising a first valve portion disposed at least partly within the cavity, the first valve portion and the interior surface defining a first fluid flow path, a second valve portion in contact with the interior surface and defining a second fluid flow path. A third valve portion is disposed at least partly within the cavity between the first and second valve portions. The second fluid flow path fluidically connects the third valve portion to a trim cavity. A filter media extends from the first valve portion to the second valve portion and divides a third fluid flow path fluidically connecting the first and seconds fluid flow paths.

The subject matter of this specification can be embodied in, among other things, a fluid flow trim apparatus includes an outer housing defining a cavity having an interior surface and an end wall having an orifice therethrough, a valve body comprising a first valve portion disposed at least partly within the cavity, the first valve portion and the interior surface defining a first fluid flow path, a second valve portion in contact with the interior surface and defining a second fluid flow path. A third valve portion is disposed at least partly within the cavity between the first and second valve portions. The second fluid flow path fluidically connects the third valve portion to a trim cavity. A filter media extends from the first valve portion to the second valve portion and divides a third fluid flow path fluidically connecting the first and seconds fluid flow paths.

The subject matter of this specification can be embodied in, among other things, a fluid flow trim apparatus includes an outer housing defining a cavity having an interior surface and an end wall having an orifice therethrough, a valve body comprising a first valve portion disposed at least partly within the cavity, the first valve portion and the interior surface defining a first fluid flow path, a second valve portion in contact with the interior surface and defining a second fluid flow path. A third valve portion is disposed at least partly within the cavity between the first and second valve portions. The second fluid flow path fluidically connects the third valve portion to a trim cavity. A filter media extends from the first valve portion to the second valve portion and divides a third fluid flow path fluidically connecting the first and seconds fluid flow paths.

The subject matter of this specification can be embodied in, among other things, a fluid flow trim apparatus includes an outer housing defining a cavity having an interior surface and an end wall having an orifice therethrough, a valve body comprising a first valve portion disposed at least partly within the cavity, the first valve portion and the interior surface defining a first fluid flow path, a second valve portion in contact with the interior surface and defining a second fluid flow path. A third valve portion is disposed at least partly within the cavity between the first and second valve portions. The second fluid flow path fluidically connects the third valve portion to a trim cavity. A filter media extends from the first valve portion to the second valve portion and divides a third fluid flow path fluidically connecting the first and seconds fluid flow paths.

A fuel injector having a body with a bore, which defines a fuel manifold. The injector also has a variable-area injector arrangement having a pintle with a conical head and a pintle spring connected to the body. The pintle spring urges a tip of the pintle to seal against an exit orifice of the body, such that application of pressurized fuel within the body causes the pintle to move. Above some threshold pressure, the pressurized fuel causes the conical head to move out of contact with the exit orifice of the body. This, in turn, provides a corresponding variable area for passage of the pressurized fuel through the exit orifice about the conical head of the pintle. The injector further includes a swirler configured to create a swirling action in the flow of pressurized fuel through the fuel manifold, wherein the manifold is upstream of the exit orifice.