WO2016057557A1

WO2016057557A1 - Structures and techniques to form repeatable gas mixtures at specific locations within a prechamber for ignition

Info

Publication number: WO2016057557A1
Application number: PCT/US2015/054298
Authority: WO
Inventors: Chunyi XIA; Robert GLIEGE
Original assignee: Advanced Green Innovations, LLC
Priority date: 2014-10-06
Filing date: 2015-10-06
Publication date: 2016-04-14
Also published as: WO2016057556A1

Abstract

Some embodiments of the invention include an igniter. The igniter may include an igniter shell defining a chamber having a prechamber; a center electrode and fuel valve assembly disposed within the chamber; one or more orifices disposed within the igniter shell; and a vortex structure disposed within the prechamber between the one or more orifices and the center electrode and fuel valve assembly.

Description

STRUCTURES AND TECHNIQUES TO FORM REPEATABLE GAS MIXTURES AT SPECIFIC LOCATIONS WITHIN A PRECHAMBER FOR IGNITION

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 62/060,348 filed October 6, 2014, entitled "STRUCTURES TO INSULATE IGNITION SYSTEM HIGH-VOLTAGE WITHIN A DIRECT INJECTION GASEOUS DIFFUSION BURN PRECHAMBER," the entirety of which is incorporated into this document for all purposes.

This application claims priority to U.S. Provisional Application No. 62/060,256 filed October 6, 2014, entitled "STRUCTURES AND TECHNIQUES TO FORM REPEATABLE GAS MIXTURES AT SPECIFIC LOCATIONS WITHIN A PRECHAMBER FOR IGNITION AND SUBSEQUENT DIFFUSION FLAME BURN," the entirety of which is incorporated into this document for all purposes.

FIELD

This disclosure relates generally to structures and techniques to form repeatable gas mixtures at specific locations within a prechamber for ignition.

BACKGROUND

The use of alternative fuels in converted heavy-duty diesel engines with high compression ratios (e.g., greater than 13: 1) require lean fueling strategies to avoid engine knock and reduced emissions. But lean fueling can be difficult to ignite. Indeed, the ignition energy required to achieve performance requirements can be large. A prechamber with a rich fuel mixture can be used to thrust ignited species from the prechamber into the main combustion chamber where it then ignites a pre -mixed lean fuel mixture. In addition, a diffusion flame fed by a direct fuel injector can be used to ignite a pre -mixed lean fuel mixture in the main combustion chamber.

SUMMARY

Some embodiments of the invention include an igniter, for example, for converted heavy-duty diesel engines. The igniter may include an igniter shell defining a chamber having a prechamber; a center electrode and fuel valve assembly disposed within the chamber; one or more orifices disposed within the igniter shell; and a vortex structure disposed within the prechamber between the one or more orifices and the center electrode and fuel valve assembly. In some embodiments, the vortex structure may create one or more fluid vortexes within the prechamber as air and/or fuel flows into the prechamber through the one or more orifices. In some embodiments, the vortex structure may be coupled with the igniter shell. In some embodiments, the vortex structure may be disposed near the distal end of the center electrode and fuel valve assembly. In some embodiments, the vortex structure may comprise a disc. In some embodiments, the vortex structure may have a ring shape with a central hole in a portion of the vortex structure that is configured to allow air and/or fuel to pass through the central hole. In some embodiments, the vortex structure may be formed as part of the igniter shell. In some embodiments, the vortex structure may include a disc with an angled bottom surface. In some embodiments, the vortex structure may include a disc with a fiat top surface. In some embodiments, the vortex structure may include a structure formed near the one or more orifices.

In some embodiments an igniter may include an igniter shell defining a prechamber; a fuel valve configured to inject fuel into the prechamber; an electrode disposed within the prechamber; one or more fluid intake orifices disposed within the igniter shell and configured to allow air and/or fuel to enter (or be forced) into the prechamber; and means for creating a fluid vortex within the prechamber when air and/or fuel enters the prechamber through the one or more fluid intake orifices.

In some embodiments, the means for creating a fluid vortex may include a fin structure disposed within the prechamber. In some embodiments, the means for creating a fluid vortex may include means for creating a fluid vortex comprises a vortex structure disposed within the prechamber.

In some embodiments an igniter may include an igniter shell defining a prechamber. The prechamber may include a main chamber, a first sub prechamber in fluid communication with the main chamber and coupled with a first end of the main chamber, and a second sub prechamber in fluid communication with the main chamber and coupled with the first end of the main chamber. The igniter may further include at least one fuel valve configured to inject fuel into the prechamber; a first electrode disposed within the first sub prechamber; a second electrode disposed within the second sub prechamber; and one or more fluid intake orifices disposed within the igniter shell on a second end of the main chamber.

In some embodiments, the first sub prechamber and the second sub prechamber may be coupled with the first end of the main chamber at an acute angle relative to one another. In some embodiments, the first sub prechamber and the second sub prechamber may be coupled with the first end of the main chamber at obtuse angles relative to the main chamber.

In some embodiments an igniter may include an igniter shell defining a prechamber; a fuel valve configured to inject fuel into the prechamber; an electrode disposed within the prechamber; and one or more fluid intake orifices disposed within the igniter shell offset relative to an axis of the inner chamber cavity of the igniter shell and configured to allow air and/or fuel to enter the prechamber.

In some embodiments, at least two of the plurality of fluid intake orifices are offset from the same axis in opposite directions. In some embodiments, at least two of the plurality of fluid intake orifices are offset from different orthogonal axis. In some embodiments, the one or more intake orifices are angularly offset relative to a horizontal axis.

These illustrative embodiments are mentioned not to limit or define the disclosure, but to provide examples to aid understanding thereof. Additional embodiments are discussed in the Detailed Description, and further description is provided there. Advantages offered by one or more of the various embodiments may be further understood by examining this specification or by practicing one or more embodiments presented.

BRIEF DESCRIPTION OF THE FIGURES

These and other features, aspects, and advantages of the present disclosure are better understood when the following Detailed Description is read with reference to the accompanying drawings.

Figure 1 is a side view of an injector/igniter disposed within an engine block.

Figures 2A, 2B, and 2C illustrate the use of a vortex structure within a prechamber according to some embodiments.

Figure 3A illustrates an example igniter with a vortex structure disposed within the prechamber according to some embodiments.

Figure 3B illustrates an example igniter with a vortex structure disposed within the prechamber according to some embodiments.

Figure 4 illustrates an example igniter with a vortex structure disposed within the prechamber according to some embodiments.

Figure 5 illustrates an example igniter with a vortex structure disposed within the prechamber according to some embodiments.

Figure 6 illustrates an example igniter with a vortex structure disposed within the prechamber according to some embodiments.

Figure 7 illustrates an example igniter with a vortex structure disposed within the prechamber according to some embodiments.

Figure 8 illustrates an example igniter with a vortex structure disposed within the prechamber according to some embodiments.

Figure 9 illustrates an example igniter with one or more vortex structures disposed within the prechamber near orifices according to some embodiments.

Figures 10A, 10B and IOC illustrate tumble mixing within a prechamber according to some embodiments.

Figures 11A and 11B illustrate an example of swirl mixing of fuel and air in a prechamber according to some embodiments.

Figure 11C illustrates non-offset fluid intake orifices according to some embodiments.

Figure 1 ID illustrates offset fluid intake orifices according to some embodiments.

Figure 1 IE illustrates offset fluid intake orifices according to some embodiments.

Figure 1 IF illustrates offset fluid intake orifices according to some embodiments.

Figure 12 illustrates a portion of a prechamber with a plurality of fluid intake orifices and a fin structure having a plurality of angled fins.

Figure 13 is a side view of a prechamber with fluid intake orifices being angled downward by an angle relative to the vertical.

DETAILED DESCRIPTION

Embodiments of the invention include a number of structures, methods, and/or techniques for forming ignitable mixtures at one or more ignition sites within a direct injection prechamber igniter (e.g., injection/igniter) for heavy-duty diesel engines converted to run on alternative fuels such as, for example, natural gas. Some embodiments include an igniter that forms a vortex structure disposed within an igniter prechamber that may create one or more ignition sites of fuel-air mixtures. Some embodiments include tumble mixing of fuel and air in a prechamber. And some embodiments include swirl mixing within a prechamber.

The embodiments described in this document may be used to form ignitable mixtures in a globally lean volume of air/fuel mixtures. This can be helpful, for example, to enable prechamber direct injection/ignition technology in the conversion of heavy-duty diesel engines to alternative gaseous fuels (e.g., compressed natural gas). Heavy-duty diesel engines may operate with excess air (e.g., lean), which is necessary for diesel fuel combustion efficiency. Alternative fuel sources, such as compressed natural gas, on the other hand, may need relatively narrow air (e.g., a greater fuel ratio) for ignition to occur. For ignition to occur in a globally lean fuel mixture, a control pocket of ignitable air-fuel mixtures can be created within a prechamber. These ignitable air-fuel mixtures can be near-stoichiometric. When ignited, either the main fuel charge is dispensed into the ignited pockets and jetted into the main chamber and combusted via diffusion-flame or the ignited mixture pocket expels into the main chamber and ignites a lean air/fuel mixture present in the main chamber.

Thus, it can be beneficial to create or form a rich mixture of air and fuel near the ignition source to enhance the performance of a prechamber designed igniter to accurately and repeatedly control an ignitable air-fuel ratio mixture. Some embodiments may include structures, methods, and/or techniques that may be used to create a fluid vortex that produces an ignitable mixture site within the prechamber that has the minimum, proper, or ideal air- fuel ratio to achieve ignition.

Generally speaking, a prechamber may comprise a partially enclosed volume that allows for the manipulation of fluid mixtures at specific locations where ignition sources can then ignite an ignitable mixture (near stoichiometric) of air/fuel mixture in an otherwise lean or ultra-lean global volume of fluid. Once ignited in the prechamber, the combustion can then ignite the primary fuel charge in the main combustion chamber that includes a lean air/fuel mixture or in a diffusion-flame manner.

Figure 1 is a side view of an injector/igniter 100 disposed within an engine head 120. The injector/igniter 100 includes a prechamber 110. Generally speaking, the prechamber 110 may be a volume within the injector/igniter 100 that allows for idealized mixture of air and fuel (e.g., a near stoichiometric mixture) for ignition within the prechamber 110, which may then cause ignition in the main chamber 115 that may, in some embodiments, have a lean fuel-air mixture (e.g., excess air versus fuel). The use of a prechamber, in such embodiments, therefore, may be useful to initiate ignition of a lean fuel-air mixture in the main chamber when initiation of such a lean fuel-air mixture may not be possible otherwise.

The main chamber 115 may be a volume defined by the engine head 120, the engine head 120, and the piston 125. Intake valve 145 and exhaust valve 135 may also be disposed within the engine head 120 and may provide intake and/or exhaust channels to and/or from the main chamber 115. During a cycle, a quantity of fuel is introduced into the prechamber 110 through a fuel intake valve. Air is then driven into the prechamber via upward movement of the piston 125 and/or the pressure differential created by prechamber orifices. Some embodiments may create near-stoichiometric air/fuel mixtures at specific ignition sites within the prechamber 110 while the main chamber 115 includes a lean environment.

Figure 2A illustrates an igniter 200 with a vortex structure 205 disposed within the prechamber 110. The vortex structure may be disposed near an electrode and valve body 230 with an ignition gap 220 disposed in between the electrode and valve body 230 and the ignition gap 220. As shown in the figure, fuel may be introduced into the prechamber 110 though the electrode and valve body 230. In Figure 2B, air and/or fuel is introduced into the prechamber 110 fluid intake orifices 240. The vortex structure 205 may force or constrain the air and/or fuel between the vortex structure 205 and the walls of the igniter 200. The vortex structure 205 may be designed and/or formed to create a vortex within the prechamber 110 near the ignition gap 220 as shown in Figure 2C. The vortex may create a mixture of fuel and air near the ignition gap 220 that includes a near-stoichiometric air and/or fuel/fuel mixture for ignition.

Figure 3 A illustrates an example igniter 300 with a vortex structure 305 disposed within the prechamber 110 according to some embodiments. The igniter 300 may be disposed within the engine head 120 so that the distal end of the igniter 300 extends into the main chamber 115. The igniter 300 includes an igniter body 315 (e.g., igniter shell), an electrode and valve body 330 (e.g., center electrode and fuel valve assembly), and a valve 340. Fuel may be introduced into the prechamber 110 through fuel inlet 332 when the valve 340, has been actuated opening a channel between the fuel inlet 332 and the prechamber 110. In some embodiments, the valve 340 may be an inward opening valve or an outward opening valve. Ignition may occur within the prechamber 110 when a spark or electrical arc occurs at the ignition gap 320.

The vortex structure 305 may be disposed within the prechamber 110 near the distal end of the electrode and valve body 330. The vortex structure 305 may be shaped and/or designed to create one or more ignitable mixture sites 370 shown in Figure 3B within the prechamber 110 using fluid dynamic principles. In this example, the vortex structure 305 has an inverted T-shaped cross-section as shown in Figures 3A and 3B. As air and/or fuel is pushed through one or more main chamber orifices 360 from a low pressure area in the main chamber 115 into the prechamber 110 when the piston 125 moves into the main chamber 115, the fluid 345 (e.g. , air and/or fuel) is forced or directed between the igniter body 315 and the vortex structure 305. As the fluid 345 passes the base of the T-shaped vortex structure 305, a vortex 310 of air and fuel may be formed between the base and the stem of the T-shaped vortex structure 305. For example, the pressure differential between the main chamber 105 and the prechamber 110 may re-direct (or force) the fluid 345 around the vortex structure 305 where the fluid 345 may separate from the structure creating one or more vortices 365 or low- pressure zones as shown in Figure 3A. The fuel may be segregated, for example, from boundary layer separation of the fluid 345 moving past the vortex structure 305, and one or more ignitable mixture sites 370 (see Figure 3B) may be created. At the one or more ignitable mixture sites 370 the fuel may be mixed into a distinct/localized ignitable mixture of air and fuel that may be surrounded by un-ignitable mixtures that may be too lean or rich.

The vortex structure 305 may be disposed between the distal end of the electrode and valve body 330 and the main chamber orifices 360. The vortex structure 305 may have a three- dimensional shape that includes a disc-shaped base with a cylindrical stem. In some embodiments, the vortex structure 305 may be disposed within the prechamber 110 with the disc-shaped base disposed toward the main chamber orifices 360 and the stem may be disposed within the prechamber 110 near the electrode and valve body 330.

The angle of the top surface, φ, of the base of the vortex structure 305 relative to vertical may be 70° or greater.

Figure 4 illustrates an example igniter 400 with a vortex structure 405 disposed within the prechamber 110 according to some embodiments. The vortex structure 405 has a donut shape (or ring shape) with a central hole 406 that is part of the volume of the prechamber 110 and through which fluid may flow and create a turbulent flow within the prechamber 110 that may result in one or more ignitable mixture sites 470. The ignitable mixture sites 470 may be created in one or more regions at least partially bounded by an upper surface 407 of the vortex structure 405, the igniter body 315, and the insulator 130.

In some embodiments, the vortex structure 405 may be coupled with the igniter body 315. In some embodiments, the vortex structure 405 may be formed from the igniter body 315. In some embodiments, the vortex structure 405 may extend from the igniter body 315. In some embodiments, the vortex structure 405 may be formed as part of the igniter body 315. The vortex structure 405 may aid in the creation of one or more ignitable mixture sites 470 that may include an ignitable mixture of fuel and air.

In some embodiments, the vortex structure 405 may have an upper surface 407 and a lower surface 408. The upper surface 407, for example, may extend from the igniter body 315 with an angle β relative to the igniter body 315. The angle β may include any angle within the following ranges 60° < β < 150°, 80° < β < 110°, 70° < β < 120°, 60° < β < 130°, and 85° < β < 95°. In some embodiments, the angle β may be approximately 90°.

The lower surface 408, for example, may extend from the igniter body 315 with an angle a relative to the igniter body 315. The angle a may include any angle within the following ranges 80° < a < 110°, 70° < a < 120°, 60° < a < 135°, 50° < a < 90°, 45° < a < 70°, and 85° < a < 95°. In some embodiments, the angle a may include an angle in the range be 0° < a < 90°. Figure 5 illustrates an example igniter 500 with a vortex structure 505 disposed within the prechamber 110 according to some embodiments. In this embodiment the vortex structure 505 comprises a single body that extends from the igniter body 315. The vortex structure 505 may have the shape of a hyperectangle (or rectangular cuboid). The vortex structure 505 may have some rounded edges and/or surfaces, acute angles between edges and/or surfaces, and/or obtuse angles edges and/or surfaces.

The vortex structure 505 may aid in the creation of turbulent fluid flow such that a vortex may be created near the vortex structure 505 within the prechamber 110. The turbulent fluid flow may create an ignitable mixture site 570. The ignitable mixture site 570 may be created in a region at least partially bounded by an upper surface of the vortex structure 505, the igniter body 315 , and the insulator 130.

Figure 6 illustrates an example igniter 600 with a vortex structure 605 disposed within the prechamber 110 according to some embodiments. In this embodiment, the vortex structure 605 may be disposed beneath the distal end of the electrode and valve body 330 such that the ignition gap 320 separates the distal end of the electrode and valve body 330 and the ignition gap 320. In some embodiments, the vortex structure 605 may be coupled or connected with the igniter body 315. In some embodiments, the vortex structure 605 may provide an electrical ground through which a spark may be generated between the electrode and valve body 330 and the vortex structure 605. The vortex structure 605 may aid in the creation of turbulent fluid flow such that a vortex may be created in the ignition gap 320 between the electrode and valve body 330 and the vortex structure 605. The vortex may create an ignitable mixture site 670 adjacent to the ignition gap 320.

In some embodiments, the vortex structure 605 may have an upper surface 607 with a v- shaped cross-section and/or a lower surface 608 with a v-shaped cross-section. In some embodiments, the vortex structure 605 may have a three dimensional disc shape with angularly concave upper surface 607 and/or an angularly convex lower surface 608. The upper surface 607, for example, may be angled upward from the center of the vortex structure at angle φ. The angle φ may include any angle within the following ranges 0° < φ < 45°, 5° < φ < 30, 10° < φ < 20°, 5° < φ < 10°, and 15° < φ < 25°. The lower surface 608, for example, may be angled upward from the center of the vortex structure 605 at angle Θ measured relative to the horizontal. The angle Θ may include any angle within the following ranges 0° < Θ < 70°, 0° < Θ < 45°, 5° < Θ < 30°, 10° < Θ < 20°, 5° < Θ < 10°, and 15° < Θ < 25°.

Figure 7 illustrates an example igniter 700 with a vortex structure 705 disposed within the prechamber 110 according to some embodiments. In this embodiment, the vortex structure 705 may be disposed beneath the distal end of the electrode and valve body 330 such that the ignition gap 320 separates the distal end of the electrode and valve body 330 and the ignition gap 320. In some embodiments, the vortex structure 705 may be coupled or connected with the igniter body 315. In some embodiments, the vortex structure 705 may provide an electrical ground through which a spark may be generated between the electrode and valve body 330 and the vortex structure 705. The vortex structure 705 may aid in the creation of turbulent fluid flow such that a vortex may be created in the ignition gap 320 between the electrode and valve body 330 and the vortex structure 705. The vortex may create an ignitable mixture site 770 adjacent to the ignition gap 320.

In some embodiments, the vortex structure 705 may have a flat or mostly flat upper surface 707 and/or a lower surface 708 with a v-shaped cross-section. In some embodiments, the vortex structure 705 may have a three dimensional disc shape and an angularly convex lower surface 708. The lower surface 708, for example, may be angled upward from the center of the vortex structure 705 at angle Θ measured relative to the horizontal. The angle Θ may include any angle within the following ranges 0° < Θ < 70°, 0° < Θ < 45°, 5° < Θ < 30°, 10° < Θ < 20°, 5° < Θ < 10°, and 15° < Θ < 25°.

Figure 8 illustrates an example igniter 800 with a vortex structure 805 disposed within the prechamber 110 according to some embodiments. In this embodiment, the vortex structure 805 may be disposed beneath the distal end of the electrode and valve body 330 such that the ignition gap 320 separates the distal end of the electrode and valve body 330 and the ignition gap 320. In some embodiments, the vortex structure 805 may be coupled or connected with the igniter body 315. In some embodiments, the vortex structure 805 may provide an electrical ground through which a spark may be generated between the electrode and valve body 330 and the vortex structure 805. The vortex structure 805 may aid in the creation of turbulent fluid flow such that a vortex may be created in the ignition gap 320 between the electrode and valve body 330 and the vortex structure 805. The vortex may create an ignitable mixture site 870 adjacent to the ignition gap 320.

In some embodiments, the vortex structure 805 may have a flat or mostly flat upper surface 807 and/or a lower surface 808 with a rounded convex cross-section. The lower surface 808, for example, may have a parabolic cross-section.

Figure 9 illustrates an example igniter 900 with one or more vortex structures 940 disposed within the prechamber 110 near orifices 260 according to some embodiments. An extended electrode 930, for example, may be disposed within the prechamber 110 having a distal end extending toward the ignitable mixture site 970. In some embodiments, the vortex structure 940 may extend from the igniter body 315 into the prechamber 110. In some embodiments, the vortex structure 940 may provide an electrical ground through which a spark may be generated between the extended electrode 930 and valve body 330 and the vortex structure 940. The vortex structure 940 may aid in the creation of turbulent fluid flow such that a vortex may be created in the ignition gap 320 between the electrode and valve body 330 and the vortex structure 940. The vortex may create the ignitable mixture site 970 adjacent to the ignition gap 320.

While two orifices are shown in Figure 9, multiple orifices 260 may be disposed within the igniter body 315. In some embodiments, multiple vortex structures 940 may be disposed by each or some of the orifices 260. The ignitable mixture site 970 may be created in one or more regions at least partially bounded by the vortex structure 940 and the igniter body 315. In some embodiments, the vortex structure 940 may be radially continuous and coupled with or formed within the igniter body 315 at a position near the orifices 260. The vortex structure 940, for example, may have a ring shape.

In some embodiments, the vortex structure 940 may be angled inwardly toward the center of the igniter body 315 at an angle φ measured relative to a vertical line and/or a line parallel to the extended electrode 930. The angle φ may include any angle within the following ranges 0° < φ < 90°, 0° < φ < 45°, 5° < φ < 15°, 0° < φ < 10°, 5° < φ < 10°, and 5° < φ < 25°.

The preceding embodiments use vortex structures to create a fuel-air vortex at one or more ignitable mixture sites within the prechamber. Other embodiments include tumble mixing of fuel and air in a prechamber of an igniter to create a fuel-air vortex within the prechamber. Figure 1 OA illustrates igniter 1000 that includes a prechamber having a main prechamber 1002 and a sub prechamber 1005. The sub prechamber 1005 may be formed from the prechamber 1002 by having a cone 1006 disposed within the prechamber as shown in the figure. The sub prechamber 1005 extends at an acute angle from a longitudinal axis of the main prechamber 1002. The sub prechamber 1005 may include one or more fuel injectors, for example, fuel injector 1015A or fuel injector 1015B (the fuel injectors collectively or individually referred to as fuel injector 1015). Fuel may be introduced into the prechamber through the fuel injectors.

Air and/or fuel may be introduced into the prechamber through fluid intake orifice 1010A and/or fluid intake orifice 1010B (the orifices collectively or individually referred to as fluid intake orifice 1010) as shown in Figure 10B. In some embodiments, more than two fluid intake orifices 1010 may be included. As the air and/or fuel enters the prechamber through the fluid intake orifices 1010, for example, the air and/or fuel may be combined and/or collimated as it passes through the main prechamber 1002. The collimated air and/or fuel may then pass into the sub prechambers 1005 and interact with the walls of the sub prechambers 1005 and/or the cone 1006. As it does so, the air and/or fuel may create a vortex within the sub prechambers 1005 and it mixes with the fuel.

As shown in Figure IOC an ignitable mixture site 1020A and an ignitable mixture site 1020 within each sub prechamber 1005. The ignitable mixture site 1020 may include an idealized mixture of air and fuel (e.g., a near stoichiometric mixture) for ignition. An electrode may also be located within each sub prechamber 1005 that may be used to create a spark and ignite the fuel within the ignitable mixture site 1020. Thus, the shape and configuration of the main prechamber 1002 and the sub prechambers 1005 may be used to create an idealized mixture of fuel and air within each sub prechamber.

Other embodiments include swirl mixing of fuel and air in a prechamber of an igniter to create a fuel-air vortex within the prechamber. Swirl mixing may create a vortex within the prechamber using off axis pre-chamber fluid intake orifices or internal angular fins. Figures 1 1 A and 1 IB illustrate an example of swirl mixing of fuel and air in a prechamber according to some embodiments.

As shown in Figure 1 1A fuel may be introduced within the prechamber 1 120 through fuel intake port 1015. Air and/or fuel may be introduced into the prechamber 1 120 through offset fluid intake orifices 1 125 (Figures 1 1C and 1 ID illustrate the arrangement of the offset fluid intake orifices 1 125). Because the air and/or fuel enters the prechamber through offset fluid intake orifices 1 125 that are offset from the inner chamber cavity of the igniter, a vortex of fluid may be created within the prechamber. As shown in Figure 1 IB, the vortex may create an idealized mixture of fuel and air at an ignitable mixture site 1 150 near enough to the electrode 1 1 10 in order to achieve ignition from a spark from the electrode 1 1 10.

Figure 1 1C is a top view of a prechamber 1 10 with non-offset fluid intake orifices 1 135. As shown by the vertical axis line 1 145 and the horizontal axis line 1 15 that are aligned with the center of the prechamber 1 10, the center axis of each non-offset fluid intake orifices 1 135 are aligned with either the vertical axis line 1 145 or the horizontal axis line 1 15.

Figure 1 ID is a top view of a prechamber 1 10 with offset fluid intake orifices 1 125. As shown by the vertical axis line 1 145 and the horizontal axis line 1 15 that are aligned with the center of the prechamber 1 10, the center axis of the offset fluid intake orifices 1 125 are not aligned with either the vertical axis line 1 145 or the horizontal axis line 1 15. Indeed, as shown in the figure, the axis of the offset fluid intake orifices 1 125 are disposed a distance, D, from either the vertical axis line 1 145 or the horizontal axis line 1 15. In this example, an interior surface of the orifices is aligned with the inner diameter or interior surface of the prechamber. In some embodiments, the distance D may be determined from D = R—r/2, where R is the inner radius of the prechamber and r is the inner radius of the fluid intake orifices 1 125. In some embodiments the distance D may be determined within the following range: 0 < D < R— r/2. The radius and/or angle of the fluid intake orifice 1 125 may vary. Figure 1 IE is a top view of a prechamber 110 with a single offset fluid intake orifice 1135. As shown by the vertical axis line 1145 aligned with the center of the prechamber 110, the center axis of the offset fluid intake orifice 1125 is not aligned with the vertical axis line 1145. Indeed, as shown in the figure, the axis of the offset fluid intake orifice 1125 is disposed a distance from either the vertical axis line 1145.

Figure 1 IF is a top view of a prechamber 110 with a single offset fluid intake orifice 1135. In this example, the prechamber 110 is not disposed centrally within the igniter body 1150. Rather, the prechamber 110 is offset relative to the igniter body 1150. As shown by the vertical axis line 1145 aligned with the center of the prechamber 110, the center axis of the offset fluid intake orifice 1125 is not aligned with the vertical axis line 1145. Indeed, as shown in the figure, the axis of the offset fluid intake orifice 1125 is disposed a distance from either the vertical axis line 1145. The center axis of the offset fluid intake orifice 1125, however, in some embodiments, may be aligned with an axis of the intake orifice 112.

In some embodiments, swirl mixing of fuel and air in a prechamber of an igniter may occur from internal angular fins. Figure 12 illustrates a portion of a prechamber with a plurality of fluid intake orifices 1225 and a fin structure 1230 having a plurality of angled fins 1235. In some embodiments, the fin structure 1230 may be disposed near the electrode 1240. The angled fins 1235 of the fin structure 1230 may direct the air and/or fuel (or fluid) introduced into the prechamber through the plurality of fluid intake orifices 1225 into a vortex by swirling the air and/or fuel around the interior of the prechamber. In some embodiments, the angled fins 1235 may be angled an angle Θ relative to the vertical where Θ, for example, is an acute angle within one of the following ranges: 0° < Θ < 70°, 5° < Θ < 15°, 0° < Θ < 10°, 5° < Θ < 10°, and 5° < Θ < 25°. The thickness, width, and/or height of the angled fins 1235 may also vary. In some embodiments, the fluid intake orifices may be angled upwardly. Figure 13, for example, is a side view of a prechamber 1310 with fluid intake orifices 1325 being angled downward by an angle β relative to the vertical. The angle β may be an obtuse angle within one of the following ranges: 90° < Θ < 155°, 90° < Θ < 180°, 95° < Θ < 145°, 100° < Θ < 120°, and 100° < Θ < 120°. In some embodiments the fluid intake orifices may be angled upwardly, for example, as shown in Figure 13 and/or offset, for example, as shown in Figure 1 ID. While various embodiments of an ignitor have been described with an electrode and valve body having an electrode and a valve, the electrode and valve are not required to be part of the same integrated assembly. For example, the electrode and valve may be separate components of the ignitor. The valve, for example, may introduce fuel into the prechamber at one location within the ignitor and the electrode may produce an ignition event at another location within the prechambers.

In addition, the term "fuel" as used in this document may refer to any type of combustible fuel. For example, fuel may include natural gas, propane, methanol, P-series fuels, diesel, gasoline, biodiesel, ethanol, kerosene, etc. The term "air" as used in this document may refer to any fluid. For example, air may include filtered air, air, air mixed with fuel, etc.

The term "substantially" means within 5% or 10% of the value referred to or within manufacturing tolerances .

Various embodiments are disclosed. The various embodiments maybe partially or completely combined to produce other embodiments.

Numerous specific details are set forth herein to provide a thorough understanding of the claimed subject matter. However, those skilled in the art will understand that the claimed subject matter may be practiced without these specific details. In other instances, methods, apparatuses, or systems that would be known by one of ordinary skill have not been described in detail so as not to obscure claimed subject matter.

The use of "adapted to" or "configured to" herein is meant as open and inclusive language that does not foreclose devices adapted to or configured to perform additional tasks or steps. Additionally, the use of "based on" is meant to be open and inclusive, in that a process, step, calculation, or other action "based on" one or more recited conditions or values may, in practice, be based on additional conditions or values beyond those recited. Headings, lists, and numbering included herein are for ease of explanation only and are not meant to be limiting.

While the present subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, it should be understood that the present disclosure has been presented for-purposes of example rather than limitation, and does not preclude inclusion of such modifications, variations, and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art.

Claims

CLAIMS That which is claimed:

1. An igniter comprising:

an igniter shell defining a chamber having a prechamber;

an electrode disposed within the chamber

a fuel valve assembly disposed within the chamber;

one or more orifices disposed within the igniter shell; and

a vortex structure disposed within the prechamber between the one or more orifices and the center electrode and fuel valve assembly, such that the vortex structure creates a vortex of fluid and gas within the prechamber.

2. The igniter according to claim 1, wherein the vortex structure is coupled with the igniter shell.

3. The igniter according to claim 1, wherein the vortex structure is disposed near a distal end of the electrode.

4. The igniter according to claim 1, wherein the vortex structure comprises a disc.

5. The igniter according to claim 1 , wherein the vortex structure has a ring shape with a central hole in a portion of the vortex structure that is configured to allow fluid to pass through the central hole.

6. The igniter according to claim 1, wherein the vortex structure formed as part of the igniter shell.

7. The igniter according to claim 1, wherein the vortex structure comprises a disc with an angled bottom surface.

8. The igniter according to claim 1, wherein the vortex structure comprises a disc with a fiat top surface.

9. The igniter according to claim 1, wherein the vortex structure comprises a structure formed near the one or more orifices.

10. The igniter according to claim 1, wherein the vortex structure creates one or more fiuid vortexes within the prechamber as fluid flows into the prechamber through the one or more orifices.

11. An igniter comprising: an igniter shell defining a prechamber;

a fuel valve configured to inject fuel into the prechamber;

an electrode disposed within the prechamber;

one or more fluid intake orifices disposed within the igniter shell and configured to allow fluid to enter into the prechamber; and

means for creating a fluid vortex within the prechamber when fluid enters into the prechamber through the one or more fluid intake orifices.

12. The igniter according to claim 11, wherein the means for creating a fluid vortex comprises a fin structure disposed within the prechamber.

13. The igniter according to claim 11, wherein the means for creating a fluid vortex comprises a vortex structure disposed within the prechamber.

14. An igniter comprising:

an igniter shell defining a prechamber comprising:

a lower chamber;

an upper chamber in fluid communication with the main chamber; and at least one fuel valve configured to inject fuel into the prechamber;

an electrode disposed within the upper chamber; and

one or more fluid intake orifices disposed within the igniter shell on a second end of the lower chamber, wherein the one or more fluid intake orifices are configured to inject fluid into the lower chamber and the upper chamber such that a vortex of fluid and fuel is created within the upper chamber.

15. The igniter according to claim 14, wherein the upper chamber is in fluid communication with a first end of the lower chamber at an acute angle.

16. An igniter comprising :

an igniter shell defining a prechamber;

a fuel valve configured to inject fuel into the prechamber;

an electrode disposed within the prechamber; and

a plurality of fluid intake orifices disposed within the igniter shell, offset relative to an axis of the prechamber, and configured to allow fluid to enter the prechamber, such that a vortex of fluid and fuel is formed within the prechamber.

17. The igniter according to claim 16, wherein at least two of the plurality of fluid intake orifices are offset from the axis in opposite directions.

18. The igniter according to claim 16, wherein the one or more intake orifices are angularly offset relative to a horizontal axis.