Fuel lance for burner of gas turbine engine

Abstract

A fuel lance includes a main body including a body wall extending from a fuel lance upstream end to a fuel lance downstream end, the main body defining a lance central axis, a conical surface connected to the body wall at the fuel lance downstream end, a tip section surrounded by the conical surface, the tip section including a tip surface having a curved shape, a plurality of fuel injection nozzles, each fuel injection nozzle extending from a fuel inlet end to a fuel outlet end that is circumferentially offset to the fuel inlet end around the lance central axis, and a central fuel channel surrounded by the body wall, the central fuel channel connected to a portion of the plurality of fuel injection nozzles to provide fluid communication between the central fuel channel and each fuel injection nozzle of the portion of the plurality of fuel injection nozzles.

Description

FUEL LANCE FOR BURNER OF GAS TURBINE ENGINEBACKGROUND

[0001] A gas turbine engine typically includes a compressor section, a turbine section, and a combustion section disposed therebetween. The compressor section includes multiple stages of rotating compressor blades and stationary compressor vanes. The combustion section typically includes a plurality of combustors. The turbine section includes multiple stages of rotating turbine blades and stationary turbine vanes. Turbine blades and vanes often operate in a high temperature environment and are internally cooled.

[0002] The combustor may include a burner in which fuel is provided to a combustion zone. Compressed air from the compressor section is also provided to the combustion zone to mix with the fuel. The mixture of fuel and air is ignited by an ignitor to form hot exhaust gas for the turbine section. The combustor may include a fuel lance to provide fuel to the burner.BRIEF SUMMARY

[0003] In one aspect, a fuel lance is provided. The fuel lance includes a main body including a body wall extending from a fuel lance upstream end to a fuel lance downstream end, the main body defining a lance central axis, a conical surface connected to the body wall at the fuel lance downstream end, a tip section surrounded by the conical surface, the tip section including a tip surface having a curved shape, a plurality of fuel injection nozzles, each fuel injection nozzle extending from a fuel inlet end to a fuel outlet end that is circumferentially offset to the fuel inlet end around the lance central axis, and a central fuel channel surrounded by the body wall, the central fuel channel connected to a portion of theplurality of fuel injection nozzles to provide fluid communication between the central fuel channel and each fuel injection nozzle of the portion of the plurality of fuel injection nozzles.

[0004] In one aspect, a method for manufacturing a fuel lance is provided. The method includes positioning a base member to place a base surface in a preferred orientation, the base member defining a lance central axis, adding a plurality of layers to the base surface to define a tube region, a first layer applied directly to the base surface, and each subsequent layer applied to a prior subsequent layer, the plurality of layers cooperating to define a plurality of fuel injection nozzles, each fuel injection nozzle extending from a fuel inlet end to a fuel outlet end that is circumferentially offset to the fuel inlet end around the lance central axis, and forming a central fuel channel in the base member, the central fuel channel connected to a portion of the plurality of fuel injection nozzles to provide fluid communication between the central fuel channel and each fuel injection nozzle of the portion of the plurality of fuel injection nozzles.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0006] FIG. l is a longitudinal cross-sectional view of a gas turbine engine taken along a plane that contains a longitudinal axis or central axis.

[0007] FIG. 2 is a perspective view of a burner suitable for use in the gas turbine engine of FIG. 1.

[0008] FIG. 3 is a cross section view of the burner of FIG. 2.

[0009] FIG. 4 is a perspective view of a fuel lance suitable for use in the burner of FIG. 2.

[0010] FIG. 5 is a transparent perspective view of the fuel lance of FIG. 4.

[0011] FIG. 6 is a front view of the fuel lance of FIG. 4.

[0012] FIG. 7 is a cross section view of the fuel lance of FIG. 4.

[0013] FIG. 8 is a flowchart of a method for manufacturing the fuel lance of FIG. 4.DETAILED DESCRIPTION

[0014] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in this description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0015] Various technologies that pertain to systems and methods will now be described with reference to the drawings, where like reference numerals represent like elements throughout. The drawings discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged apparatus. It is to be understood that functionality that is described as being carried out by certain system elements may be performed by multiple elements. Similarly, for instance, an element may be configured to perform functionality that is described as being carried out by multiple elements. The numerous innovative teachings of the present application will be described with reference to exemplary non-limiting embodiments.

[0016] Also, it should be understood that the words or phrases used herein should be construed broadly, unless expressly limited in some examples. For example, the terms “including”, “having”, and “comprising”, as well as derivatives thereof, mean inclusionwithout limitation. The singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Further, the term “and / or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. The term “or” is inclusive, meaning and / or, unless the context clearly indicates otherwise. The phrases “associated with” and “associated therewith” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like. Furthermore, while multiple embodiments or constructions may be described herein, any features, methods, steps, components, etc. described with regard to one embodiment are equally applicable to other embodiments absent a specific statement to the contrary.

[0017] Also, although the terms “first”, “second”, “third” and so forth may be used herein to refer to various elements, information, functions, or acts, these elements, information, functions, or acts should not be limited by these terms. Rather these numeral adjectives are used to distinguish different elements, information, functions or acts from each other. For example, a first element, information, function, or act could be termed a second element, information, function, or act, and, similarly, a second element, information, function, or act could be termed a first element, information, function, or act, without departing from the scope of the present disclosure.

[0018] Also, in the description, the terms “axial” or “axially” refer to a direction along a longitudinal axis of a gas turbine engine. The terms “radial” or “radially” refer to a direction perpendicular to the longitudinal axis of the gas turbine engine. The terms “downstream” or “aft” refer to a direction along a working flow direction. The terms “upstream” or “forward” refer to a direction against the working flow direction.

[0019] In addition, the term “adjacent to" may mean that an element is relatively near to but not in contact with a further element or that the element is in contact with the further portion, unless the context clearly indicates otherwise. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Terms“about” or “substantially” or like terms are intended to cover variations in a value that are within normal industry manufacturing tolerances for that dimension. If no industry standard is available, a variation of twenty percent would fall within the meaning of these terms unless otherwise stated.

[0020] FIG. 1 illustrates an example of a gas turbine engine 100 including a compressor section 102, a combustion section 104, and a turbine section 106 arranged along a central axis 112. The compressor section 102 includes a plurality of compressor stages 114 with each compressor stage 114 including a set of stationary compressor vanes 116 or adjustable guide vanes and a set of rotating compressor blades 118. A rotor 134 supports the rotating compressor blades 118 for rotation about the central axis 112 during operation. In some constructions, a single one-piece rotor 134 extends the length of the gas turbine engine 100 and is supported for rotation by a bearing at either end. In other constructions, the rotor 134 is assembled from several separate spools that are attached to one another or may include multiple disk sections that are attached via a bolt or plurality of bolts.

[0021] The compressor section 102 is in fluid communication with an inlet section 108 to allow the gas turbine engine 100 to draw atmospheric air into the compressor section 102. During operation of the gas turbine engine 100, the compressor section 102 draws in atmospheric air and compresses that air for delivery to the combustion section 104. The illustrated compressor section 102 is an example of one compressor section 102 with other arrangements and designs being possible.

[0022] In the illustrated construction, the combustion section 104 is an annular combustor 120 including a plurality of separate burners that each operate to mix a flow of fuel with the compressed air from the compressor section 102 and to combust that fuel-air mixture to produce a flow of high temperature, high pressure combustion gases or exhaust gas 122. Of course, many other arrangements of the combustion section 104 are possible.

[0023] The turbine section 106 includes a plurality of turbine stages 124 with each turbine stage 124 including a number of stationary turbine vanes 126 and a number of rotating turbine blades 128. The turbine stages 124 are arranged to receive the exhaust gas 122 from the combustion section 104 at a turbine inlet 130 and expand that gas to convert thermal andpressure energy into rotating or mechanical work. The turbine section 106 is connected to the compressor section 102 to drive the compressor section 102. For gas turbine engines 100 used for power generation or as prime movers, the turbine section 106 is also connected to a generator, pump, or other device to be driven. As with the compressor section 102, other designs and arrangements of the turbine section 106 are possible.

[0024] An exhaust portion 110 is positioned downstream of the turbine section 106 and is arranged to receive the expanded flow of exhaust gas 122 from the final turbine stage 124 in the turbine section 106. The exhaust portion 110 is arranged to efficiently direct the exhaust gas 122 away from the turbine section 106 to assure efficient operation of the turbine section 106. Many variations and design differences are possible in the exhaust portion 110. As such, the illustrated exhaust portion 110 is but one example of those variations.

[0025] A control system 132 is coupled to the gas turbine engine 100 and operates to monitor various operating parameters and to control various operations of the gas turbine engine 100. In preferred constructions the control system 132 is typically micro-processor based and includes memory devices and data storage devices for collecting, analyzing, and storing data. In addition, the control system 132 provides output data to various devices including monitors, printers, indicators, and the like that allow users to interface with the control system 132 to provide inputs or adjustments. In the example of a power generation system, a user may input a power output set point and the control system 132 may adjust the various control inputs to achieve that power output in an efficient manner.

[0026] The control system 132 can control various operating parameters including, but not limited to variable inlet guide vane positions, fuel flow rates and pressures, engine speed, valve positions, generator load, and generator excitation. Of course, other applications may have fewer or more controllable devices. The control system 132 also monitors various parameters to assure that the gas turbine engine 100 is operating properly. Some parameters that are monitored may include inlet air temperature, compressor outlet temperature and pressure, combustor outlet temperature, fuel flow rate, generator power output, bearing temperature, and the like. Many of these measurements are displayed for the user and are logged for later review should such a review be necessary.

[0027] FIG. 2 illustrates a perspective view of a burner 200 suitable for use in the gas turbine engine 100 of FIG. 1. The burner 200 is a part of the combustor 120 that produces the exhaust gas 122. A plurality of burners 200 are arranged circumferentially around the central axis 108 of the gas turbine engine 100 and are spaced apart from each other to define an annular combustor 120, with other arrangements being possible. The burner 200 may be operated with different kinds of fuel, for example, gaseous fuel, or liquid fuel, or dual fuel including both gaseous fuel and liquid fuel.

[0028] The burner 200 includes an entry zone 202, a swirl zone 204 downstream of the entry zone 202, a mixing zone 206 downstream of the swirl zone 204, and an exit zone 208 downstream of the mixing zone 206. Upstream and downstream are defined with respect to a working flow direction 224. The entry zone 202 has a general cylindrical shape, with other geometries possible.

[0029] The swirl zone 204 includes a plurality of swirlers 212 that extend between the entry zone 202 and the mixing zone 206. The plurality of swirlers 212 are circumferentially arranged around a burner central axis 214 and are spaced apart from each other. Each swirler 212 has a curved surface, with other geometries possible.

[0030] The mixing zone 206 includes an outer wall 210 that extends between the swirl zone 204 and the exit zone 208. The outer wall 210 defines a mixing zone interior 216 that receives the mixture of fuel and air from the swirl zone 204 for further mixing. A plurality of air exit holes 222 are defined on the outer wall 210. The plurality of air exit holes 222 are circumferentially arranged around the outer wall 210 and are spaced apart from each other. The mixing zone 206 has a general cylindrical shape, with other geometries possible.

[0031] The exit zone 208 includes an exit surface 218. A plurality of pilot fuel exit holes 220 are defined on the exit surface 218. The plurality of pilot fuel exit holes 220 are circumferentially arranged around the exit surface 218 and are spaced apart from each other. The exit zone 208 has a general truncated conic shape, with other geometries possible.

[0032] FIG. 3 illustrates a cross section view of the burner 200. The entry zone 202 includes a main fuel supply channel 302, and a pilot fuel supply channel 304. The main fuelsupply channel 302 receives main fuel and guides the main fuel to the swirlers 212. Each swirler 212 includes a plurality of main fuel nozzles 306 to inject the main fuel into the swirl zone 204. The swirlers 212 swirl compressed air provided from the compressor section 102. The compressed air is mixed with the main fuel injected by the swirlers 212 to produce a mixture of fuel and air. The pilot fuel supply channel 304 receives pilot fuel and guides the pilot fuel to the swirler 212. A fuel lance 400 is also disposed in the entry zone 202 to receive the main fuel from a fuel lance channel 324 and inject the main fuel into the swirl zone 204 to be mixed with the compressed air.

[0033] The mixing zone 206 includes an inner wall 308 and an intermediate wall 310 that is disposed between the outer wall 210 and the inner wall 308. A pilot fuel passage 312 is defined between the outer wall 210 and the intermediate wall 310. The pilot fuel passage 312 extends along a length of the mixing zone 206. The pilot fuel passage 312 receives the pilot fuel from the pilot fuel supply channel 304 via the swirlers 212 and injects the pilot fuel to the exit zone 208 through the pilot fuel exit holes 220.

[0034] A cooling flow passage 314 is defined between the intermediate wall 310 and the inner wall 308. The cooling flow passage 314 extends along the length of the mixing zone 206. The cooling flow passage 314 receives cooling air and guides a portion of the cooling air flowing along the inner wall 308 before exiting the burner 200 through the air exit holes 222. The cooling air may be provided from the compressor section 102 or other sources exterior of the burner 200.

[0035] A plurality of film cooling holes 316 are arranged on the inner wall 308. The film cooling holes 316 are arranged in a plurality of rows 318. The rows 318 extend between a mixing zone upstream end 320 and a mixing zone downstream end 322. The mixing zone upstream end 320 is where the fuel starts to interact with the inner wall 308. The mixing zone downstream end 322 is as close to an exit of the burner 200.

[0036] The rows 318 are spaced apart from and parallel to each other along the burner central axis 214. The rows 318 are evenly distributed between the mixing zone upstream end 320 and the mixing zone downstream end 322 with the same distance between adjacent rows 318. Each row 318 includes more than one film cooling holes 316 that are arrangedcircumferentially around the inner wall 308 and are spaced apart from each other. The film cooling holes 316 in adjacent rows 318 are arranged staggered in the circumferential direction, that means the film cooling holes 316 in two directly adjacent rows 318 are positioned offset in the circumferential direction. The film cooling holes 316 are manufactured by additive manufacturing, or other suitable manufacturing methods.

[0037] In the arrangement shown in FIG. 3, the plurality of film cooling holes 316 have the same configuration and geometry. Each row 318 includes the same number of film cooling holes 316. In other arrangements, the film cooling holes 316 may have different configurations, such as different geometries, different orientations, different numbers of film cooling holes 316 in each row 318, rows 318 are not evenly distributed between the mixing zone upstream end 320 and the mixing zone downstream end 322 along the burner central axis 214, and / or film cooling holes 316 in adjacent rows 318 may be arranged aligned to each other in the circumferential direction, etc.

[0038] FIG. 4 illustrates a perspective view of the fuel lance 400. The fuel lance 400 includes a main body 402 having a body wall 404. The main body 402 defines a lance central axis 410. The body wall 404 extends from a fuel lance upstream end 406 to a fuel lance downstream end 408 along the lance central axis 410. The main body 402 has a cylindrical shape.

[0039] A conical surface 414 is coupled to the body wall 404 at the fuel lance downstream end 408. A plurality of fuel exit holes 412 are arranged on the conical surface 414 and are circumferentially spaced apart from each other with respect to the lance central axis 410. In the embodiment illustrated in FIG. 4, eight fuel exit holes 412 are evenly distributed on the conical surface 414 in the circumferential direction around the lance central axis 410. In other embodiments, different numbers and arrangements of the fuel exit holes 412 are possible, for example, more or few than eight fuel exit holes 412 may be arranged on the conical surface 414, and the fuel exit holes 412 may be unevenly distributed on the conical surface 414 in the circumferential direction, etc.

[0040] A tip section 416 is surrounded by the conical surface 414 and extends out downstream from the conical surface 414. The tip section 416 includes a tip surface 418that has a curved shape. The curved shaped tip surface 418 defines a streamline shaped tip section 416. The tip section 416 is a portion of a ellipsoid. In other embodiment, the tip section 416 may be a portion of a sphere, such as hemisphere.

[0041] FIG. 5 illustrates a transparent perspective view of the fuel lance 400. FIG. 6 illustrates a front view of the fuel lance 400. With reference of FIG. 5 and FIG. 6, the main body 402 defines a central fuel channels 502 and an outer fuel channel 504 surrounded by the body wall 404. The central fuel channel 502 is disposed at the center of the main body 402 and extends along the lance central axis 410. The central fuel channel 502 is a circular tube. The outer fuel channel 504 is disposed between the body wall 404 and the central fuel channel 502 and surrounds the central fuel channel 502. The outer fuel channel 504 has an annular tube shape having an outer circular tube 602 and an inner circular tube 604. The outer circular tube 602, the inner circular tube 604, and the central fuel channel 502 are concentric. In other embodiments, the fuel lance 400 may have more or fewer than two layers of fuel channels, for example, the fuel lance 400 may have one single fuel channel, or additional fuel channels disposed between the central fuel channel 502 and the outer fuel channel 504 or between the outer fuel channel 504 and the body wall 404, etc.

[0042] The fuel lance 400 includes a plurality of fuel injection nozzles 506. Each fuel injection nozzle 506 extends from a fuel inlet end 508 to a fuel outlet end 510 that is circumferentially offset to the fuel inlet end 508 around the lance central axis 410. A portion of the plurality of fuel injection nozzles 506 are connected to the central fuel channel 502 at the fuel inlet ends 508 to provide fluid communication between the central fuel channel 502 and the portion of the plurality of fuel injection nozzles 506. The remaining portion of the plurality of fuel injection nozzles 506 are connected to the outer fuel channel 504 at the fuel inlet ends 508 to provide fluid communication between the outer fuel channel 504 and the remaining portion of the plurality of fuel injection nozzles 506. In the embodiment illustrated in FIG. 5, four fuel injection nozzles 506 are in fluid communication with the central fuel channel 502 through four fuel inlet ends 508, respectively, and four fuel injection nozzles 506 are in fluid communication with the outer fuel channel 504 through four fuel inlet ends 508, respectively.

[0043] The fuel injection nozzle 506 includes a first portion 512 and a second portion 514. The first portion 512 has a tube shape and extends from the fuel inlet end 508 to an intermediate point 516. The second portion 514 has a tube shape and extends from the intermediate point 516 to the fuel outlet end 510. A diameter of the first portion 512 is larger than a diameter of the second portion 514. The first portion 512 extends along a curved path. The second portion 514 extends along a straight path. The plurality of fuel injection nozzles 506 follow the same curved path with each other. In other embodiments, the plurality of fuel injection nozzles 506 may follow different curved path from each other, or the portion of the fuel injection nozzles 506 connected to the central fuel channel 502 may follow the same first curved path, the remaining portion of the fuel injection nozzles 506 connected to the outer fuel channel 504 may follow the same second curved path that is different from the first curved path, etc.

[0044] The fuel outlet end 510 extends through the conical surface 414 defining the fuel exit hole 412. The plurality of conical surfaces 414 are evenly distributed along a circle on the conical surface 414 with respect to the lance central axis 410. A diameter of the circle is larger than a diameter of the central fuel channel 502 and a diameter of the outer circular tube 602 of the outer fuel channel 504.

[0045] The fuel lance 400 is manufactured by additive manufacturing, or other suitable manufacturing methods. In one construction, a selective laser melting process is used to manufacture the fuel lance 400 in a layer-by-layer process. The second portion 514 of the fuel injection nozzles 506 including the fuel exit holes 412 is manufactured by a material removing process, such as electrical discharge machining, or other suitable manufacturing methods.

[0046] FIG. 7 illustrates a cross section view of the fuel lance 400. The conical surface 414 is arranged at an acute angle 702 with respect to a plane that is perpendicular to the lance central axis 410. The fuel is injected through the fuel exit holes 412 in a fuel injection direction 704 that is perpendicular to the conical surface 414. The fuel injection direction 704 has an angle with respect to the lance central axis 410 that equals the acute angle 702. The acute angle 702 is a sharp angle between o degree to 30 degree.

[0047] In the embodiment illustrated in FIG. 7 , the fuel lance 400 is symmetric about the lance central axis 410. In other embodiments, the fuel lance 400 may be asymmetric about the lance central axis 410.

[0048] FIG. 8 illustrates a flowchart of a method 800 for manufacturing the fuel lance 400. The method 800 uses an additive manufacturing process such as or similar to a selective laser melting process. In step 802, the method 800 provides a base member having a base surface, the base member defining a lance central axis. In step 804, the method 800 adds a plurality of layers to the base surface to define a tube region, a first layer applied directly to the base surface, and each subsequent layer applied to a prior subsequent layer, the plurality of layers cooperating to define a plurality of fuel injection nozzles each fuel injection nozzle extending from a fuel inlet hole to a fuel exit hole that is circumferentially offset to the fuel inlet hole around the lance central axis. In step 806, the method 800 forms a central fuel channel in the base member, the central fuel channel extending from a central fuel upstream end to a central fuel downstream end, the central fuel upstream end connected to a portion of the plurality of fuel injection nozzles to provide fluid communication between the central fuel channel and each fuel injection nozzle of the portion of the plurality of fuel injection nozzles.

[0049] During operation, the main fuel enters the central fuel channel 502 of the fuel lance 400 from the fuel lance upstream end 406. The main fuel is guided by the central fuel channel 502 and flow into the fuel exit holes 412 and is injected into the swirl zone 204 through the fuel exit holes 412. A co-flow of air (not shown) may be provided to surround the fuel exit holes 412. The co-flow air may results in a re-circulation zone after the fuel exit holes 412 due to the sharp acute angle 702 The sharp acute angle 702 is designed for liquid fuel injection to function as desired. When operation on liquid fuel, the liquid fuel is injected at high pressure and travels away from the fuel exit holes 412. As such the liquid fuel is not sucked into the re-circulation zone. However, when operation on gaseous fuel, the gaseous fuel is injected close to the fuel lance 400. The gaseous fuel may be sucked into the re-circulation zone which may cause high levels of dynamics due to the unsteady flow. If the gaseous fuel is hydrogen, the introduction of the hydrogen into the re-circulation zone may result in flame holding. The streamline shaped tip section 416 streams the flow of theinjected fuel and reduces occurrence of the re-circulation zone after the fuel exit holes 412. The combination of the conical surface 414 and the streamline shaped tip section 416 provides the fuel lance 400 that can be operated on liquid fuel, gaseous fuel, and hydrogen.

[0050] Although an exemplary embodiment of the present disclosure has been described in detail, those skilled in the art will understand that various changes, substitutions, variations, and improvements disclosed herein may be made without departing from the spirit and scope of the disclosure in its broadest form.

[0051] None of the description in the present application should be read as implying that any particular element, step, act, or function is an essential element, which must be included in the claim scope: the scope of patented subject matter is defined only by the allowed claims. Moreover, none of these claims are intended to invoke a means plus function claim construction unless the exact words "means for" are followed by a participle.LISTING OF DRAWING ELEMENTS100 gas turbine engine102 compressor section104 combustion section106 turbine section108 inlet section110 exhaust portion112 central axis114 compressor stage116 stationary compressor vanerotating compressor blade combustor exhaust gas turbine stage stationary turbine vane rotating turbine blade turbine inlet control system rotor burner entry zone swirl zone mixing zone exit zone outer wall swirler burner central axis mixing zone interior exit surface pilot fuel exit holeair exit hole working flow direction main fuel supply channel pilot fuel supply channel main fuel nozzle inner wall intermediate wall pilot fuel passage cooling flow passage film cooling hole row mixing zone upstream end mixing zone downstream end fuel lance channel fuel lance main body body wall fuel lance upstream end fuel lance downstream end lance central axisfuel exit hole conical surface tip section tip surface central fuel channel outer fuel channel fuel injection nozzle fuel inlet end fuel outlet end first portion second portion intermediate point outer circular tube inner circular tube acute angle fuel injection direction method step step step

Claims

CLAIMSWhat is claimed is:

1. A fuel lance comprising: a main body including a body wall extending from a fuel lance upstream end to a fuel lance downstream end, the main body defining a lance central axis; a conical surface connected to the body wall at the fuel lance downstream end; a tip section surrounded by the conical surface, the tip section including a tip surface having a curved shape; a plurality of fuel injection nozzles, each fuel injection nozzle extending from a fuel inlet end to a fuel outlet end that is circumferentially offset to the fuel inlet end around the lance central axis; and a central fuel channel surrounded by the body wall, the central fuel channel connected to a portion of the plurality of fuel injection nozzles to provide fluid communication between the central fuel channel and each fuel injection nozzle of the portion of the plurality of fuel injection nozzles.

2. The fuel lance of claim 1, further comprising an outer fuel channel disposed between the outer wall and the central fuel channel and surrounding the central fuel channel, wherein the outer fuel channel is connected to a remining portion of the plurality of fuel injection nozzles to provide fluid communication between the outer fuel channel and each fuel injection nozzle of the remining portion of the plurality of fuel injection nozzles.

3. The fuel lance of claim 2, wherein each fuel injection nozzle comprises a first portion extending from the fuel inlet end to an intermediate point and a second portion extending from the intermediate point to the fuel outlet end.

4. The fuel lance of claim 3, wherein the first portion extends along a curved shape path.

5. The fuel lance of claim 4, wherein the plurality of fuel injection nozzles follow the same curved path with each other.

6. The fuel lance of claim 3, wherein the second portion extends along a straight path.

7. The fuel lance of claim 2, wherein the fuel outlet end extends through the conical surface forming a fuel exit hole.

8. The fuel lance of claim 7, wherein the fuel exit hole is one of a plurality of fuel exit holes that are distributed along a circle on the conical surface with respect to the burner central axis.

9. The fuel lance of claim 8, wherein the central fuel channel has a circular tube shape and the outer fuel channel has an annular tube shape comprising an outer circular tube and an inner circular tube, and wherein a diameter of the circle is larger than a diameter of the central fuel channel and a diameter of the outer circular tube.

10. The fuel lance of claim 1, wherein the tip section is a portion of an ellipsoid.

11. A method for manufacturing a fuel lance, the method comprising: positioning a base member to place a base surface in a preferred orientation, the base member defining a lance central axis; adding a plurality of layers to the base surface to define a tube region, a first layer applied directly to the base surface, and each subsequent layer applied to a prior subsequent layer, the plurality of layers cooperating to define a plurality of fuel injection nozzles, each fuel injection nozzle extending from a fuel inlet end to a fuel outlet end that is circumferentially offset to the fuel inlet end around the lance central axis; and forming a central fuel channel in the base member, the central fuel channel connected to a portion of the plurality of fuel injection nozzles to provide fluid communication between the central fuel channel and each fuel injection nozzle of the portion of the plurality of fuel injection nozzles.

12. The method of claim 11, further comprising forming an outer fuel channel in the base member, the outer fuel channel connected to a remining portion of the plurality of fuel injection nozzles to provide fluid communication between the outer fuel channel and each fuel injection nozzle of the remining portion of the plurality of fuel injection nozzles.

13. The method of claim 12, further comprising forming the base member, the central fuel channel, and the outer fuel channel by adding a plurality of layers along the lance central axis.

14. The method of claim 12, further comprising forming a tip section by adding a plurality of layers on a conical surface of the tube region along the lance central axis, wherein the tip section is surrounded by the conical surface and has a curved shape.

15. The method of claim 14, further comprising forming each fuel injection nozzle in a first portion extending from the fuel inlet end to an intermediate point and a second portion extending from the intermediate point to the fuel outlet end, wherein the fuel outlet end extends through the conical surface forming a fuel exit hole.

16. The method of claim 15, further comprising forming the first portion along a curved path.

17. The method of claim 16, further comprising forming the plurality of fuel injection nozzles following the same curved path with each other.

18. The method of claim 15, further comprising forming the second portion along a straight path using a material removing process.

19. The method of claim 14, further comprising forming a plurality of fuel exit holes distributed along a circle on the conical surface with respect to the burner central axis, wherein the fuel exit hole is one of the plurality of fuel exit holes, wherein the central fuel channel has a circular tube shape and the outer fuel channel has an annular tube shape comprising an outer circular tube and an inner circular tube, and wherein a diameter of the circle is larger than a diameter of the central fuel channel and a diameter of the outer circular tube.

20. The method of claim 11, wherein the preferred orientation comprises a direction to place the base surface in a horizontal direction.

Images