商發(fā)四期航空發(fā)動機帶熱防護結(jié)構(gòu)的燃油噴嘴5-專利全文us2013341430a1

1、US 20130341430A1(i9) United States(12)Patent Application PublicationHall et al.oo) Pub. No.: US 2013/0341430 AlDec. 26,2013(43) Pub. Date:(54)ACTIVE PURGE MECHANISM WITH BACKLOW PREVENTER FOR GAS TURBINE FUEL INJECTORS(52)U.S. Cl.USPC239/533.2(75)Inventors:Troy Hall, Prole, IA (US); Mark Alan Caples

2、, Ankeny, IA (US)Delavan Inc., West Des Moines, IA (US) 13/530,731Jun. 22, 2012(57)ABSTRACTA fuel injector for a gas turbine engine includes an injector body having a feed arm with a nozzle body mounted thereto. A fuel conduit fluidly connects a fuel inlet portion of the feed arm to a fuel circuit i

3、n the nozzle body to form a fuel path through the injector body and an insulative gap is defined between the fuel conduit and an inside of the feed arm wall to thermally insulate the fuel path of the injector body. An aper ture through the feed arm wall provides fluid communication between the insul

4、ative gap and ambient conditions existing on an outside of the feed arm wall.(73)(21)Assignee:Appl.No.:(22)Filed:Publication ClassificationInt.Cl.F02M 63/00(51)(2006.01)Patent Application PublicationDec. 26, 2013Sheet 1 of 10US 2013/0341430 A1Fig.1Patent Application PublicationDec. 26, 2013Sheet 2 o

5、f 10US 2013/0341430 A1HOFig. 2Patent ApplicationPublicationDec. 26, 2013Sheet 3 of 10US 2013/0341430 A1140Fig. 3Patent Application PublicationDec. 26, 2013Sheet 4 of 10US 2013/0341430 A1Fig. 4AmPurge Fluid InFig. 4CPatent Application PublicationDec. 26, 2013Sheet 5 of 10US 2013/0341430 A1Fig.SBPaten

6、t Application PublicationDec. 26, 2013 Sheet 6 of 10US 2013/0341430 A1Patent Application PublicationDec. 26, 2013 Sheet 7 of 10Patent Application PublicationDec. 26, 2013 Sheet 8 of 10US 2013/0341430 A1Patent Application PublicationDec. 26, 2013 Sheet 9 of 10US 2013/0341430 A1Fig. 8BPatent Applicati

7、on PublicationDec. 26, 2013Sheet 10 of 10US 2013/0341430 A1Fig. 8CUS 2013/0341430 A1Dec. 26, 20131ACTIVE PURGE MECHANISM WITH BACKLOW PREVENTER FOR GAS TURBINE FUEL INJECTORSSUMMARY OF THE INVENTION0008 The purpose and advantages ofthe present invention will be set forth in and become apparent from

8、the description that follows. Additional advantages of the invention will be realized and attained by the methods and systems particularly pointed out in the written description and claims hereof, as well as from the appended drawings.0009 To achieve these and other advantages and in accor dance wit

9、h the purpose of the invention, as embodied herein, the invention includes a fuel injector for a gas turbine engine. The fuel injector has an injector body including a feed arm having a feed arm wall, and a nozzle body connected thereto. A fuel conduit fluidly connects a fuel inlet portion of the fe

10、ed arm to a fuel circuit in the nozzle body to form a fuel path through the injector body. An insulative gap is defined between an inside ofthe feed arm wall and the fuel conduit to thermally insulate the fuel path of the injector body. An aper ture is formed through the feed arm wall. The aperture

11、pro vides fluid communication between the insulative gap and ambient conditions existing outside of the feed armwall.0010 In certain embodiments, a valve is disposed in the aperture to allow fluid flow (e.g., ambient air) in one direction and inhibit fluid (e.g., fuel) flow in a second direction. Mo

12、re over, the valve can include, for example: a ball check valve, a reed check valve, a Tesla valve, or any other suitable type of valves. In addition, the aperture can be defined at various suitable locations in the feed arm wall. For example, the feed arm wall can have a downstream side facing a di

13、rection com mon with an outlet of the nozzle body, and an upstream side facing an opposite direction of the downstream side. The aperture can be defined in the feed arm wall on the down stream side, the upstream side, or between (e.g., a lateral side) the downstream and upstream sides.0011 In accord

14、ance with certain other embodiments, a tortuous path or helical passages are formed relative to the inside of the feed arm wall to provide fluid communication from the aperture to the insulative gap. The tortuous path or helical passages can be configured and adapted to allow fluid flow such as a ga

15、s flowthrough the aperture into the insulative gap, yet also to inhibit fluid flow such as fuel flow from the insulative gap through the aperture by forming a blockage in the helical passage. For example, the fluid that flows from outside the feed arm wall into the insulative gap can be a gas such a

16、s ambient air and the fluid that is inhibited from flowing from the insulative gap to the outside of the feed arm wall can be fuel. Fuel can be inhibited by the tortuous path (e.g., slowed) and, thus, exposed to high temperatures for a period of time. At such temperatures, the fuel can “coke” (e.g.,

17、 form a solid carbonaceous material) and form a blockage in the tortuous path. In this fashion, the tortuous path prevents fuel from flowing from the insulative gap through the aperture.0012 These and other features ofthe systems and methods ofthe subject invention will become more readily apparent

18、to those skilled in the art from the following detailed description of the preferred embodiments taken in conjunction with the drawings.BACKGROUND OF THE INVENTION0001 1. Field of the Invention0002 The present invention relates to injectors and nozzles for gas turbine engines, and more particularly,

19、 to mechanisms for purging fuel within a fuel injectors for gas turbine engines.0003 2. Description of Related Art0004 A variety of devices and methods are known in the art for injecting fuel into gas turbine engines. Of such devices, many are directed to injecting fuel into combustors of gas turbin

20、e engines under high temperature conditions. For example, fuel injectors for gas turbine engines on an aircraft direct fuel from a manifold to a combustion chamber of a combustor. This fuel injector typically has an inlet fitting connected to the manifold for receiving the fuel, a fuel nozzle locate

21、d within the combustor for spraying fuel into the com bustion chamber, and a housing stem extending between and fluidly interconnecting the inlet fitting and the fuel nozzle. The housing stem typically has a mounting flange for attach ment to the casing of the combustor.0005 Fuel injectors are typic

22、ally heat-shielded because of high operating temperatures arising from high temperature gas turbine compressor discharge air flowing around the housing stem and nozzle. The heat shielding prevents the fuel passing through the injector from breaking down into its constituent components (i.e., “coking

23、”), which may occur when the wetted wall temperatures of a fuel passage exceed 400 F. Coking in the fuel passages of a fuel injector can build up to restrict fuel flow to the nozzle.0006 Typically, conventional injectors include annular stagnant air gaps as insulation between external walls, such as

24、 those in thermal contact with high temperature ambient con ditions, and internal walls in thermal contact with the fuel. In order to accommodate differential expansion of the internal and external walls while minimizing thermally induced stresses, the walls are anchored at one end and free at the o

25、ther end for relative movement. If the downstream tip ends of the walls are left free for relative movement, even a close fitting sliding interface between the downstream tip ends can allow fuel to pass into the air gap formed between the walls. For example, fuel can be drawn into these air gaps due

26、 to a capillary effect due to changing pressures when the engine is shut down. Ultimately, this can result in fuel being stored in the air gaps. When the fuel becomes sufficiently heated, the fuel can break down and form carbon in the air gap, which carbon is not as good of an insulator as air, or,

27、prior to breaking down, the fuel can even combust. Such combustion can ultimately damage the fuel injector and, in extreme cases, can damage the entire engine causing a failure. In addition, the carbon may build up to a point where it blocks venting of the air gap to the stem, which can lead to dimi

28、nished injector service life and may require frequent and costly cleaning of the fuel injector.0007 Such conventional methods and systems generally have been considered satisfactory for their intended purpose. However, there still remains a continued need in the art for nozzles and fuel injectors th

29、at properly insulate while reduc ing or preventing fuel entry (and thus carbon entry) in the insulation gaps. The present invention provides a solution for these problems.BRIEF DESCRIPTION OF THE DRAWINGS0013 So that those skilled in the art to which the subject invention appertains will readily und

30、erstand how to make and use the devices and methods of the subject invention withoutUS 2013/0341430 A1Dec. 26, 20132undue experimentation, preferred embodiments thereof will be described in detail herein below with reference to certain figures, wherein:0014 FIG. l is a perspective view of a first re

31、presentative embodiment ofan injector constructed in accordance with the present invention, showing a fuel injector with a nozzle body mounted to a gas turbine engine combustor;0015 FIG. 2 is a perspective view of an upstream face of the fuel injector, showing a feed arm having an aperture formed th

32、ere-through;0016 FIG. 3 is a cross-sectional side elevation view of the fuel injector, showing a fuel conduit inside the feed arm and an insulative gap;0017 FIG. 4A is a an exploded perspective view of a ball check valve constructed in accordance with a second exem plary embodiment of the invention,

33、 showing a an inner hous ing, a ball, and an outer housing;0018 FIG. 4B is a cross-sectional perspective view of the ball check valve of FIG. 4A, shown in an open position; 0019 FIG. 4C is a cross-sectional perspective view of the ball check valve of FIG. 4A, shown in a closed position; 0020 FIG. 5A

34、 is a perspective view of a reed check valve assembly;0021 FIG. 5B is a perspective view of the fuel injector of FIG. 1, constructed in accordance with another exemplary embodiment of the invention, showing a reed check valve disposed therein;0022 FIG. 5C is a cross-sectional side elevation view of

35、the injector in FIG. 5B, taken at cut-line 5C-5C, showing a path of fluid flow through theaperture;0023 FIG. 5D is a cross-sectional plan view, taken at cut- line 5D-5D of FIG. C, showing the reed check valve in closed position;0024 FIG. 5E is the cross-sectional plan view of FIG. 5D, showing the re

36、ed check valve in an open position;0025 FIG. 6A is a cross-sectional perspective view of a portion of the fuel injector of FIG. 1, showing a Tesla valve disposed therein;0026 FIG. 6B is an sectional perspective view of a top portion ofthe Tesla valve of FIG. 6A, showing the Tesla valve defined in th

37、e feed arm wall;0027 FIG. 7A is a cross-sectional perspective view of the fuel injector of FIG. 1, showing the aperture with a Tesla valve in fluid communication there-with;0028 FIG. 7B is a perspective view of a top portion of the Tesla valve of FIG. 7A, showing the Tesla valve fluid path way;0029

38、FIG. 8A is a perspective view of an exemplary embodiment of a helical passage constructed in accordance with the present invention, showing the reed check valve disposed therein;0030 FIG. 8B is a perspective view of the fuel injector of FIG. 1, showing the helical passage of FIG. 8A and the reed che

39、ck valve, disposed therein; and0031 FIG. 8C is a cross-sectional elevation view, taken at cut-line 8C-8C of FIG. 8B, showing the helical passage with the reed check valve in closed position.of an exemplary embodiment of an injector in accordance with the invention is shown in FIG. 1 and is designate

40、d gen erally by reference character 100. Other embodiments of injectors and nozzles in accordance with the invention, or aspects thereof, are provided in FIGS. 2-8C, as will be described herein. The devices and methods of the invention can be used in gas turbine engines, or in any other suitable app

41、lication, for enhanced injector performance.0033 As shown in FIG. 1, a portion of a typical gas turbine engine system 100 is illustrated. In operation, compressed air from a compressor (not shown) is discharged into compressor discharge chamber 105. Fuel is introduced to the compressed air by a fuel

42、 injector 110. The fuel-air mixture is then com busted in a combustion chamber 115. Fuel injector 110 receives fuel from a fuel supply line 120, and is secured to an engine housing 125 via mount fitting 132. Fuel injector 110 also includes a feed arm 130, a nozzle body 135 and a nozzle body outlet 1

43、40, which issues the fuel-air mixture to the combustion chamber 115.0034 Referring now to FIG. 2, an upstream face of fuel injector 110 includes an aperture 205 formed through the wall of feed arm 130. As discussed below, aperture 205 allows ambient air to flow there-through and into an insulative g

44、ap, which, prevents capillary intake of fuel during engine opera tion and purges trapped fuel that enters the injector, for example upon shut-down. Notably, as discussed herein, an upstream direction and a downstream direction are defined relative to nozzle body 135.0035 With reference now to FIG. 3

45、, airflow through aper ture 205 into insulative gap 305 is described. A fuel supply line 120 fluidly connects to a fuel conduit 310. In particular, fuel supply line 120 provides fuel to an inlet portion 303 of feed arm 130. Fuel conduit 310 fluidly connects fuel inlet portion 303 to a fuel circuit i

46、n nozzle body 135, which and forms a fuel path through injector body 110. An insulative gap 305 inside of feed arm 130 is defined between an inner wall of feed arm 130 and fuel conduit 310.0036 Insulative gap 305 thermally insulates the fuel path through fuel conduit 310 from ambient conditions. Ins

47、ulative gap 305 is important for reducing or preventing coking that can occur if the fuel reaches temperatures around 400 F. In operation, aperture 205 allows an effective amount of air to pass there-through and into insulative gap 305 to puige fuel from insulative gap 305, without compromising the

48、insulative properties of insulative gap 305. The air that passes through insulative gap 305 puiges fuel from insulative gap 305 from capillary intake ofthe fuel from nozzle body outlet 140 during engine shut-down. For example, capillary intake of fuel from nozzle body outlet 140 can occur during eng

49、ine shut-down from pressure changes that naturally occur when combustion ceases (e.g., a temporary pressure vacuum can occur at nozzle body outlet 140). Further, local pressure at aperture 205 dur ing normal engine operation (e.g., high pressure compressor discharge) is greater than local pressure c

50、onditions down stream at outlet 140 into to combustion. Therefore, a positive air flow exists through aperture 205 through insulative gap 305 and along fuel conduit 310 and out through nozzle body outlet 140. In this fashion, any fuel that enters the injector, during operation or shut-down condition

51、s is purged from insulative gap 305 by air flow through aperture 205, which follows a path of less resistance through the insulative gap 305 out through nozzle body outlet 140. Moreover, the air thatDETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS0032 Reference will now be made to the drawings wher

52、ein like reference numerals identify similar structural features or aspects of the subject invention. For purposes of explanation and illustration, and not limitation, a partial viewUS 2013/0341430 A1Dec. 26, 20133enters insulative gap 305 is sufficiently heated so as to remove any internal carbon d

53、eposits that can occur through a pyro lytic process.0037 Still referring to FIG. 3, nozzle body 135 includes additional insulative gaps 315, which further provide thermal insulation for fuel throughout the fuel circuit. These gaps may be separated from insulative gap 305 or, optionally, may be in fl

54、uid communication with insulative gap 305.0038 The particular location of aperture 205 disposed in feed arm 130 is exemplary only. Those skilled in the art will appreciate that aperture 205 can be disposed in feed arm 130 at any suitable location in feed arm 130 without departing form the spirit and

55、 scope of the invention. For example, the aperture can be disposed in a downstream side ofthe feed arm wall facing a direction common with nozzle body outlet 140, an upstream side of the feed arm wall facing an opposite direction of downstream, or in a lateral side of the feed arm wall between the u

56、pstream side and the downstream side. Preferably, the aperture is located on a downstream side and/ or a lateral side so that any debris in the ambient air (e.g., from the compressor discharge chamber) does not block the aper ture. Moreover, aperture 205 can be disposed in the feed arm wall in a loc

57、ation closer to mount fitting 132, or closer to nozzle body 135. Importantly, the pressure conditions at the position of aperture 205 should be greater than the pressure conditions of nozzle body outlet 140 such that there is posi tive fluid flow through insulative gap 305.0039 Referring now to FIGS

58、. 4A-4C, in another exem plary embodiment a check feature disposed within aperture 205, which, in turn, is disposed within feed arm 130. Specifi cally, FIG. 4A illustrates a local perspective exploded view of a ball check valve 405 spaced apart from an outboard opening of aperture 205. Ball check valve 405 includes an outer hous ing 410, a ball 415, and an inner housing 420. Ball 415 and inner housing 420 are disposed within outer housing 410, and outer housing 410 and inner housing 420 are annular. B