Sundstrand Corporation

Michael W Sledd

Jack R Shekleton

Steven A Sachrison

Kent I Weber

Edward S Blain

Stuart Alexander Greenwood

Robert L Bracken

Tim Sullivan

Steven S Sachrison

Linn C Shorb

An engine is provided having a fuel supply system which includes apparatus of straightforward construction that is powered solely by a flow of fuel through a delivery line to the engine for increasing the flow of fuel through the delivery line to the engine during start-up of the engine. A small control volume of pressurized fuel is stored during a preceding operational period of the engine for use in augmenting the fuel flow to the engine during a subsequent start-up of the engine. A converter apparatus is also disclosed for converting a portion of the fuel flow from the control volume and/or from a main fuel pump into an increased flow rate or pressure of fuel to the engine during the subsequent start-up. The control volume of fuel is stored in such a manner that volume compensation for changes in ambient temperature is provided, and in such a manner that the fuel line is positively shut off during periods of inoperation such that the fuel cannot leak out or evaporate and thus not be available for rapid start-up of the engine during a subsequent start.

Fuel pump assist for engine starting

In order to achieve ignition at altitude, particularly in relatively small combustors (10) with low fuel flow rates, a fuel injection system (20) includes an air nozzle (26), a fuel nozzle (28), and an air assist tube (34). The fuel nozzle (28) is disposed in a manner so as to direct fuel through the air nozzle (26) and includes a fuel metering orifice (30) or capillary tube (32) to control fuel flow therethrough. The air assist tube (34) is integrally associated with the fuel nozzle (28) downstream of the fuel metering orifice (30) or capillary tube (32) to accelerate fuel flowing through the fuel nozzle (28). With this arrangement, the air nozzle (26) may comprise an opening in a combustor wall (14) defining a combustion chamber (12) of a turbine engine combustor (10) wherein a combustor case (16) surrounds the combustor wall (14) to define an air flow path 18 in communication with a compressed air source whereby compressed air flows through the opening (26) and into the combustor (10) along with fuel from the fuel nozzle (28) and air from the air assist tube (34).

Air assist fuel injection system

Difficulties in downsizing annular combustors (20) due to orienting fuel injectors with respect to oxidant blast tubes are avoided in a construction for a combustor (20) including radially spaced annular walls (22, 24) and an interconnecting radial wall (26) defining an annular combustion chamber (32). A plurality of circumferentially spaced tubes (28, 30) extend through the radially outermost annular wall (24) and are directed generally tangentially into the combustion space (32). A plurality of fuel injectors (42) are provided for directing fuel radially inwardly into the space (32) and are circumferentially spaced about the combustion space (32) and located between the tubes (28).

Tangentially directed air assisted fuel injection and small annular

In order to enhance fuel injection efficiency, and particularly to atomize low fuel flows at high velocity with low fuel pressure, a fuel injection system 24 for a combustor 22 of a turbine engine 20 has an air blast tube 48 and a fuel supply tube 76. The air blast tube 48 is mounted at an acute angle relative to a wall 26 of the combustor 22 and has a first end 50 in communication with the combustor 22 and a second, enlarged end 52 disposed at an acute angle to an axis 54 of the air blast tube 48 in communication with a source of compressed air externally of the wall 26 of the combustor 22. The air blast tube 48 is operable to deliver compressed air from the source into the combustor 22. The fuel supply tube 76 delivers fuel through a fuel supply orifice 58 to a point at or near the first end 50 of the air blast tube 48 and has a first end 60 in communication with the combustor 22 through the fuel supply orifice 58 and a second end 62 in communication with a source of fuel externally of the wall 26 of the combustor 22. With this arrangement, the fuel supply tube 76 extends to a point communicating internally with the air blast tube 48 but adjacent a discharge opening 64 of the air blast tube 48 to produce an enhanced atomized fuel/air mixture thereby.

Air blast fuel injecton system

The high cost of fuel injection nozzles for a gas turbine engine may be reduced by utilizing nozzles (60) formed of simple tubes (63) of capillary cross section having an integral flange (62) formed on one end (86) thereof.

Improved fuel injector for a gas turbine engine

Poor atomization of fuel at low fuel flows in a gas turbine engine may be overcome in an engine including a rotary compressor (14), a turbine wheel (22) coupled to the compressor (14) to drive the same and a nozzle of (26) for directing gases of combustion at the turbine wheel (22). An annular combustor (34) defines a combustion annulus about the turbine wheel (22) and has an outlet (30) connected to the nozzle (26). A plurality of air blast tubes (50) include exit openings (52) circumferentially spaced about the combustor (32) and each has an axis (54) that is generally circumferentially directed with respect to the combustion annulus. A fuel discharge orifice (64) is located within each air blast tube (50) and a flange (66) is aligned with each orifice (64) in the path of fuel being discharged therefrom and at a substantial acute angle (.theta.) to the axis (54).

Air blast tube impingement fuel injector for a gas turbine engine

Combustor fuel injection system

Improved fuel atomization for turbine engines operating at low fuel flows and at high altitudes is accomplished in an engine 10 having an annular combustor 12 by utilizing fuel injectors 18 provided with fuel supply tubes 24 disposed within air tubes 20 wherein the fuel supply tubes 24 each have an exit orifice 26 internally of the corresponding air tube 20 and upstream of an exit orifice 22 thereof with a fuel impingement surface 28 being provided within the air tube 20 in confronting relation to the exit orifice 26 of the fuel supply tube 24 to produce a conical fuel film 36 subjected to pressurized air to enhance fuel atomization.

Turbine engine with pin injector

Improved fuel atomization for turbine engines operating at low fuel flows and at high altitudes is accomplished in an engine having an annular combustor 26 by utilizing start fuel injectors 46 provided with discharge orifices 56 and planar impingement surfaces 60 within the path of fuel discharged from the orifices 56 to provide flat sprays 62 that are generally tangential to the annular combustor 26 so as to be intercepted by an igniter 70 in a radial wall 34 of the combustor 26.

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Vista, CA, United States of America

Michael W Sledd