Dual-vortex flow field reverse-flow combustor

Abstract

The application discloses a double-vortex flow field backflow combustion chamber, which comprises a combustion chamber case, a diffuser connected to the combustion chamber case, a plurality of fuel nozzles, a flame tube connected to the combustion chamber case, and a vortex generator connected between each fuel nozzle and the head of the flame tube. A plurality of outer ring main combustion holes and a plurality of inner ring main combustion holes are respectively arranged on the outer wall surface and the inner wall surface of the flame tube. The outer ring main combustion holes and the inner ring main combustion holes are arranged on both sides of a center ring surface surrounded by the center lines of the plurality of fuel nozzles and are arranged one by one in a one-to-one correspondence, so that the outer ring main jet and the inner ring main jet interact, and then an outer ring backflow vortex and an inner ring backflow vortex distributed on both sides of the center ring surface are formed in the flame tube. The combustion chamber can construct a double-vortex flow field in the main combustion area of the flame tube without increasing the number of combustion chamber nozzles, the number of main combustion holes of the flame tube and the flow of inlet air, improve the uniformity of the oil mist field in the main combustion area, and obtain a uniform temperature field.

Description

Technical Field

[0001] This invention relates to the field of aero-engine combustion chamber technology, and in particular, to a dual-vortex flow field recirculation combustion chamber. Background Technology

[0002] With advancements in aero-engine technology, the requirements for engine combustor performance, such as temperature rise, outlet temperature, and lifespan reliability, are becoming increasingly stringent, and will likely remain so in the future. This necessitates a reduction in the proportion of air intake from the main combustion port and mixing port while simultaneously improving the quality of the temperature field within the combustor. To meet these requirements, the uniformity of the oil mist field within the combustor's flame tube needs to be enhanced. Since the flame tube of an aero-gas turbine recirculation combustor features counter-current air intake, it typically forms a single-vortex flow field structure in the main combustion zone, which is detrimental to improving the uniformity of the oil mist field within the flame tube. This disadvantage is even more pronounced in high-temperature recirculation combustors.

[0003] There are two main technical directions for improving the temperature field quality of high-temperature reflux combustion chambers: one is to increase the number of combustion chamber nozzles, and the other is to increase the number of main combustion holes and the air flow rate into the main combustion holes.

[0004] In the existing technology, increasing the number of combustion chamber nozzles increases the cost of the combustion chamber. As the number of nozzles increases, the starting and ignition performance of the combustion chamber is generally reduced. Increasing the number of main combustion holes and the air flow into the main combustion holes will indirectly reduce the cooling air flow of the flame tube, which is detrimental to the life of the flame tube and indirectly increases the cost of the combustion chamber. At the same time, it is not conducive to further improving the temperature rise level of the combustion chamber, thus limiting the improvement of the overall performance of the combustion chamber. Summary of the Invention

[0005] This invention provides a dual-vortex flow field recirculation combustor to solve the technical problem of designing a high-quality temperature field, which is difficult to design in the main combustion zone flow field and uniform oil mist field under counter-current intake conditions in the recirculation combustor flame tube of an aero-gas turbine.

[0006] The technical solution adopted in this invention is as follows:

[0007] A dual-vortex flow field recirculation combustion chamber includes: a combustion chamber casing, a diffuser connected to the combustion chamber casing and multiple fuel nozzles, a flame tube connected to the combustion chamber casing, and a vortex generator connected between each fuel nozzle and the flame tube head; the diffuser and multiple fuel nozzles extend into the combustion chamber casing, and the multiple fuel nozzles are arranged sequentially at intervals along the circumference of the flame tube head end face; multiple outer ring main combustion holes and multiple inner ring main combustion holes are respectively provided on the outer and inner walls of the flame tube, so that the outlet airflow entering from the diffuser enters the flame tube through the vortex generator, the outer ring main combustion holes and the inner ring main combustion holes respectively; the outer ring main combustion holes and the inner ring main combustion holes are respectively located on both sides of a central ring surface formed by the center lines of multiple fuel nozzles and are arranged one-to-one, so that the outer ring main jet entering from the outer ring main combustion holes and the inner ring main jet entering from the inner ring main combustion holes interact, thereby forming an outer ring recirculation vortex and an inner ring recirculation vortex distributed on both sides of the central ring surface in the flame tube.

[0008] Furthermore, the flame tube has an annular cavity structure, including an inner ring and an outer ring located on the inner and outer sides, and a head heat shield located at the head of the flame tube; multiple outer ring main combustion holes are evenly spaced on the outer ring wall of the flame tube, and multiple inner ring main combustion holes are evenly spaced on the inner ring wall of the flame tube; the head heat shield is annular and connects the air intake side of the inner ring of the flame tube and the air intake side of the outer ring of the flame tube, and multiple fuel nozzles are evenly spaced on the circumference of the head heat shield.

[0009] Furthermore, the distance H / 2 between the outer ring of the flame tube and the central ring surface is equal to the distance between the inner ring of the flame tube and the central ring surface, and multiple outer ring main combustion holes and multiple inner ring main combustion holes are symmetrically arranged about the central ring surface to form symmetrically arranged outer ring reflux vortices and inner ring reflux vortices on both sides of the central ring surface.

[0010] Furthermore, the number of fuel nozzles is equal to the number of outer ring main combustion holes or inner ring main combustion holes, and the center lines of the outer ring main jet, the inner ring main jet, and the fuel nozzles are all located in the same plane.

[0011] Furthermore, the outer ring main combustion orifice and the inner ring main combustion orifice have an axial distance D along the centerline of the fuel nozzle, and the inner ring main combustion orifice is closer to the fuel nozzle.

[0012] Furthermore, the centerline of the inner ring main combustion orifice and the centerline of the inner ring main jet have an included angle α, where 0°≤α≤15°.

[0013] Furthermore, the head heat shield is provided with spray holes corresponding to the injection ends of each fuel nozzle, or with annular injection ports corresponding to the injection ends of multiple fuel nozzles arranged in a ring, so as to allow fuel to be injected into the flame tube.

[0014] Furthermore, the outer boundary of the fuel cone that the fuel nozzle injects atomized fuel through the nozzle orifice or injection ring forms the atomized fuel cone angle B, and 80°≤B≤140°.

[0015] Furthermore, the head heat shield includes a head heat shield ring plate, an upper guide ring plate, and a lower guide ring plate. The head heat shield ring plate is annular and connects the inner ring air intake side of the flame tube and the outer ring air intake side of the flame tube, with the nozzle or injection ring opening on the head heat shield ring plate. The upper guide ring plate and the lower guide ring plate are symmetrically arranged on the upper and lower sides of the nozzle or injection ring opening, with one side of each fixed to the inner side of the head heat shield ring plate, and the opposite side extending obliquely towards the outer ring and inner ring of the flame tube, respectively, to guide the fuel injected by the fuel nozzle and control the fuel atomization cone angle.

[0016] Furthermore, the outflow side of the inner ring of the flame tube and the outflow side of the outer ring of the flame tube are respectively fixedly connected to the combustion chamber casing to form a whole.

[0017] The present invention has the following beneficial effects:

[0018] In the dual-vortex flow field recirculation combustion chamber of this invention, the outlet airflow entering from the diffuser enters the flame tube through the outer ring main combustion orifice, the inner ring main combustion orifice, and the vortex generator. Since the outer ring main combustion orifice and the inner ring main combustion orifice are respectively located on both sides of the central annular surface formed by the centerlines of multiple fuel nozzles and are arranged in a one-to-one correspondence, the outer ring main jet entering from the outer ring main combustion orifice and the inner ring main jet entering from the inner ring main combustion orifice can interact, thereby forming an outer ring recirculation vortex and an inner ring recirculation vortex distributed on both sides of the central annular surface within the flame tube. This allows for the combustion chamber to achieve this without increasing the number of nozzles, the number of main combustion orifices in the flame tube, or the intake airflow. A double-vortex flow field is constructed in the main combustion zone within the flame tube to improve the uniformity of the fuel mist field in the main combustion zone, thereby obtaining a uniform temperature field, improving the quality of the combustion chamber temperature field, and solving the design problem of a high-quality temperature field in a high-temperature rise-back combustion chamber. Through numerical simulation analysis and engine whole-machine test verification, the test results show that the temperature rise of the double-vortex flow field recirculation combustion chamber exceeds K, the number of flame tube heads and fuel nozzles in the combustion chamber can be reduced to a few, the combustion chamber cost is low and the economy is good, and the intake volume of the main combustion hole is small and the fuel-air ratio in the main combustion zone is high, thus solving the design problem of a high-quality temperature field in a high-temperature rise-back combustion chamber and further improving the performance level of the combustion chamber.

[0019] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 This is a cross-sectional view of the dual-vortex flow field recirculation combustion chamber structure according to a preferred embodiment of the present invention;

[0022] Figure 2 This is a cross-sectional view of the flow field structure of the double vortex flow field recirculation combustion chamber according to a preferred embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram showing the relative positions of the main combustion holes in the flame tube of the double vortex flow field recirculation combustion chamber according to a preferred embodiment of the present invention.

[0024] Legend:

[0025] 10. Combustion chamber casing; 20. Diffuser; 30. Fuel nozzle; 40. Flame tube; 401. Outer ring main combustion orifice; 402. Inner ring main combustion orifice; 41. Inner ring of flame tube; 42. Outer ring of flame tube; 43. Head heat shield; 431. Nozzle; 432. Head heat shield ring plate; 433. Upper guide ring plate; 434. Lower guide ring plate; 50. Swirl generator; 601. Outlet airflow; 602. Central annular surface; 603. Outer ring reflux vortex; 604. Outer ring main jet; 605. Outer ring main jet centerline; 606. Outer ring main combustion orifice centerline; 607. Inner ring reflux vortex; 608. Inner ring main jet; 609. Inner ring main jet centerline; 610. Inner ring main combustion orifice centerline. Detailed Implementation

[0026] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0027] Reference Figure 1-2A preferred embodiment of the present invention provides a dual-vortex flow field recirculation combustion chamber, comprising: a combustion chamber casing 10, a diffuser 20 and a plurality of fuel nozzles 30 connected to the combustion chamber casing 10, a flame tube 40 connected within the combustion chamber casing 10, and a vortex generator 50 connecting each fuel nozzle 30 and the flame tube head. The diffuser 20 and the plurality of fuel nozzles 30 extend into the combustion chamber casing 10, and the plurality of fuel nozzles 30 are arranged sequentially at intervals along the circumferential direction of the flame tube head end face. The outer wall and inner wall of the flame tube 40 are respectively provided with a plurality of outer ring main combustion holes 401 and a plurality of inner ring main combustion holes 402 penetrating the wall, so that the outlet airflow 601 entering from the diffuser 20 enters the flame tube 40 through the vortex generator 50, the outer ring main combustion holes 401 and the inner ring main combustion holes 402 respectively. The outer ring main combustion port 401 and the inner ring main combustion port 402 are respectively located on both sides of the central ring surface 602 formed by the center lines of multiple fuel nozzles 30 and are arranged in a one-to-one correspondence, so that the outer ring main jet 604 entering from the outer ring main combustion port 401 and the inner ring main jet 608 entering from the inner ring main combustion port 402 interact, thereby forming an outer ring reflux vortex 603 and an inner ring reflux vortex 607 distributed on both sides of the central ring surface 602 in the flame tube 40.

[0028] In the dual-vortex flow field recirculation combustion chamber of the present invention, the outlet airflow 601 entering through the diffuser 20 enters the flame tube 40 through the outer ring main combustion port 401, the inner ring main combustion port 402, and the vortex generator 50. Since the outer ring main combustion port 401 and the inner ring main combustion port 402 are respectively located on both sides of the central annular surface 602 formed by the centerlines of multiple fuel nozzles 30 and are arranged in a one-to-one correspondence, the outer ring main jet 604 entering through the outer ring main combustion port 401 and the inner ring main jet 608 entering through the inner ring main combustion port 402 can interact, thereby forming an outer ring recirculation vortex 603 and an inner ring recirculation vortex 607 distributed on both sides of the central annular surface 602 within the flame tube 40. This allows for combustion without increasing the number of combustion chamber nozzles. Under the conditions of the number of main combustion holes and intake air flow, a double vortex flow field is constructed in the main combustion zone within the flame tube 40 to improve the uniformity of the oil mist field in the main combustion zone, thereby obtaining a uniform temperature field, improving the quality of the combustion chamber temperature field, and solving the design problem of a high-quality temperature field in a high-temperature rise-back combustion chamber. Through numerical simulation analysis and engine whole-machine test verification, the test results show that the temperature rise of the double vortex flow field recirculation combustion chamber exceeds 1100K, the number of flame tube heads and fuel nozzles in the combustion chamber can be reduced to 12, the combustion chamber has low cost and good economy, and the intake air volume of the main combustion holes is small and the oil-air ratio in the main combustion zone is high, thus solving the design problem of a high-quality temperature field in a high-temperature rise-back combustion chamber and further improving the performance level of the combustion chamber.

[0029] Optionally, such as Figure 1As shown, the flame tube 40 has an annular cavity structure, including an inner ring 41 and an outer ring 42 located on the inner and outer sides, and a head heat shield 43 located at the head of the flame tube. Multiple outer ring main combustion holes 401 are evenly spaced circumferentially on the outer ring wall, and multiple inner ring main combustion holes 402 are evenly spaced circumferentially on the inner ring wall, thereby ensuring that the outer ring main jet 604 and inner ring main jet 608 are evenly injected circumferentially. The head heat shield 43 is annular and connects the air intake side of the inner ring 41 and the air intake side of the outer ring 42. Multiple fuel nozzles 30 are evenly spaced circumferentially on the head heat shield 43, so that fuel is evenly injected into the flame tube 40 along the circumferential direction at the head of the flame tube 40, thereby improving the uniformity of the fuel mist field in the main combustion zone and obtaining a uniform temperature field.

[0030] Optionally, such as Figure 3 As shown, the distance H / 2 between the outer ring 42 of the flame tube and the central ring surface 602 is equal to the distance between the inner ring 41 of the flame tube and the central ring surface 602, that is, the outer ring 42 and the inner ring 41 of the flame tube are symmetrically arranged about the central ring surface 602; and multiple outer ring main combustion holes 401 and multiple inner ring main combustion holes 402 are symmetrically arranged about the central ring surface 602, so as to form symmetrically arranged outer ring reflux vortex 603 and inner ring reflux vortex 607 on both sides of the central ring surface 602, thereby causing the outer ring main jet 604 and the inner ring main jet 608 to interact, constructing an approximately symmetrical double vortex flow field in the main combustion zone within the flame tube 40, so as to further improve the uniformity of the oil mist field in the main combustion zone, obtain a more uniform temperature field, further improve the quality of the combustion chamber temperature field, and solve the design problem of high-quality temperature field in high-temperature rise reflux combustion chamber.

[0031] Furthermore, such as Figure 2 As shown, the number of fuel nozzles 30 is equal to the number of outer ring main combustion holes 401 or inner ring main combustion holes 402, and the center lines of the outer ring main jet 604 (center line 605), the inner ring main jet 608 (center line 609), and the fuel nozzles 30 are all located in the same plane. During operation, the outer ring main jet 604 entering the outer ring main combustion hole 401 and the inner ring main jet 608 entering the inner ring main combustion hole 402 interact to form a more approximately symmetrically distributed outer ring reflux vortex 603 and inner ring reflux vortex 607 within the flame tube. Fuel enters the flame tube 40 through the fuel nozzles 30 to form atomized fuel. The atomized fuel is entrained and mixed by the outer ring reflux vortex 603 and inner ring reflux vortex 607 to form a more uniform fuel mist field, which participates in combustion and forms a higher quality uniform temperature field.

[0032] Preferably, such as Figure 3 As shown, the outer ring main combustion hole 401 and the inner ring main combustion hole 402 have an axial distance D along the centerline of the fuel nozzle 30, and the inner ring main combustion hole 402 is closer to the fuel nozzle 30.

[0033] Preferably, such as Figure 3 As shown, there is an angle α between the centerline 610 of the inner ring main combustion orifice 402 and the centerline 609 of the inner ring main jet 608, where 0°≤α≤15°. Within this angle range, the outer ring reflux vortex 603 and the inner ring reflux vortex 607 have small differences in size, making it easier to achieve uniform fuel distribution and thus beneficial for obtaining a high-quality temperature field. Similarly, there is an angle α between the centerline 606 of the outer ring main combustion orifice 401 and the centerline 605 of the outer ring main jet 604, where 0°≤α≤15°.

[0034] Optionally, such as Figure 1 As shown, the head heat shield 43 is provided with spray holes 431 corresponding to the injection ends of each fuel nozzle 30, or with annular injection ports corresponding to the injection ends of multiple fuel nozzles 30 arranged in a ring, so as to allow fuel to be sprayed into the flame tube 40.

[0035] Preferably, such as Figure 2 As shown, the fuel nozzle 30 injects atomized fuel through the nozzle orifice 431 or the injection ring, and the outer boundary of the fuel cone forms the atomized fuel cone angle B, where 80°≤B≤140°. Within this angle range, the outer annular vortex 603 and the inner annular vortex 607 are relatively large, which is beneficial for fuel diffusion to form a uniform fuel distribution, thereby obtaining a high-quality temperature field. Generally, B does not need to be greater than 140°, as this may bring other problems that are not conducive to the combustion chamber.

[0036] Optionally, such as Figure 1 As shown, the head heat shield 43 includes a head heat shield ring plate 432, an upper guide ring plate 433, and a lower guide ring plate 434. The head heat shield ring plate 432 is annular and connects the air inlet side of the inner ring 41 of the flame tube and the air inlet side of the outer ring 42 of the flame tube, with the nozzle 431 or injection ring opening on the head heat shield ring plate 432. The upper guide ring plate 433 and the lower guide ring plate 434 are symmetrically arranged on the upper and lower sides of the nozzle 431 or injection ring opening, with one side of each fixed to the inner side of the head heat shield ring plate 432, and the opposite side extending obliquely towards the outer ring 42 and the inner ring 41 of the flame tube, respectively, to guide the fuel injected by the fuel nozzle 30 and control the fuel atomization cone angle.

[0037] Preferably, such as Figure 1 As shown, the outflow side of the inner ring 41 of the flame tube and the outflow side of the outer ring 42 of the flame tube are fixedly connected to the combustion chamber casing 10 to form a whole, so as to enhance the overall structural strength and working stability of the recirculation combustion chamber.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dual-vortex flow field recirculation combustion chamber, characterized in that, include: Combustion chamber casing (10), diffuser (20) connected to combustion chamber casing (10) and multiple fuel nozzles (30), flame tube (40) connected to combustion chamber casing (10), and vortex generator (50) connected between each fuel nozzle (30) and the flame tube head. The diffuser (20) and multiple fuel nozzles (30) extend into the combustion chamber casing (10) respectively, and the multiple fuel nozzles (30) are arranged sequentially at intervals along the circumference of the end face of the flame tube head; The outer and inner walls of the flame tube (40) are also provided with multiple outer ring main combustion holes (401) and multiple inner ring main combustion holes (402) that penetrate the wall, so that the outlet airflow (601) entering from the diffuser (20) can enter the flame tube (40) through the vortex generator (50), the outer ring main combustion holes (401) and the inner ring main combustion holes (402) respectively; The outer ring main combustion port (401) and the inner ring main combustion port (402) are respectively located on both sides of the central ring surface (602) formed by the center lines of multiple fuel nozzles (30) and are arranged in a corresponding manner, so that the outer ring main jet (604) entering from the outer ring main combustion port (401) and the inner ring main jet (608) entering from the inner ring main combustion port (402) interact with each other, thereby forming an outer ring reflux vortex (603) and an inner ring reflux vortex (607) distributed on both sides of the central ring surface (602) in the flame tube (40). The number of fuel nozzles (30) is equal to the number of outer ring main combustion holes (401) or inner ring main combustion holes (402), and the center line of the outer ring main jet (605) of the corresponding outer ring main jet (604), the center line of the inner ring main jet (609) of the inner ring main jet (608), and the center line of the fuel nozzle (30) are located in the same plane; The inner ring main combustion hole (402) centerline (610) and the inner ring main jet (608) centerline (609) have an angle α, and 0°≤α≤15°. Within this angle range, the outer ring reflux vortex (603) and inner ring reflux vortex (607) have a small size difference, which makes it easier to achieve uniform fuel distribution and is conducive to obtaining a high-quality temperature field. Similarly, the outer ring main combustion hole (401) centerline (606) and the outer ring main jet (604) centerline (605) have an angle α, and 0°≤α≤15°.

2. The dual-vortex flow field recirculation combustion chamber according to claim 1, characterized in that, The flame tube (40) is an annular cavity structure, including an inner ring (41) and an outer ring (42) of the flame tube located on the inner and outer sides, and a head heat shield (43) located at the head of the flame tube. Multiple outer ring main combustion holes (401) are evenly spaced along the circumference on the outer ring wall of the flame tube, and multiple inner ring main combustion holes (402) are evenly spaced along the circumference on the inner ring wall of the flame tube. The head heat shield (43) is ring-shaped and connected between the air intake side of the inner ring (41) of the flame tube and the air intake side of the outer ring (42) of the flame tube. Multiple fuel nozzles (30) are evenly spaced along the circumference of the head heat shield (43).

3. The dual-vortex flow field recirculation combustion chamber according to claim 2, characterized in that, The distance H / 2 between the outer ring (42) of the flame tube and the central ring surface (602) is equal to the distance between the inner ring (41) of the flame tube and the central ring surface (602). Multiple outer ring main combustion holes (401) and multiple inner ring main combustion holes (402) are symmetrically arranged about the central ring surface (602) to form symmetrically arranged outer ring reflux vortex (603) and inner ring reflux vortex (607) on both sides of the central ring surface (602).

4. The dual-vortex flow field recirculation combustion chamber according to claim 3, characterized in that, The outer ring main combustion hole (401) and the inner ring main combustion hole (402) have an axial distance D along the centerline direction of the fuel nozzle (30), and the inner ring main combustion hole (402) is closer to the fuel nozzle (30).

5. The dual-vortex flow field recirculation combustion chamber according to claim 3, characterized in that, The head heat shield (43) is provided with a nozzle (431) corresponding to the injection end of each fuel nozzle (30), or a ring-shaped injection port corresponding to the injection end of multiple fuel nozzles (30) arranged in a ring, so that fuel can be injected into the flame tube (40).

6. The dual-vortex flow field recirculation combustion chamber according to claim 5, characterized in that, The fuel nozzle (30) injects atomized fuel through the nozzle (431) or the injection ring to form the atomized fuel cone angle B, and 80°≤B≤140°.

7. The dual-vortex flow field recirculation combustion chamber according to claim 5, characterized in that, The head heat shield (43) includes a head heat shield ring (432), an upper guide ring (433) and a lower guide ring (434). The head heat insulation ring plate (432) is ring-shaped and is connected between the air intake side of the inner ring (41) of the flame tube and the air intake side of the outer ring (42) of the flame tube, and the nozzle (431) or spray ring opening is opened on the head heat insulation ring plate (432). The upper guide ring plate (433) and the lower guide ring plate (434) are symmetrically arranged on the upper and lower sides of the nozzle (431) or the injection ring. One side of each is fixed to the inner side of the head heat insulation ring plate (432), and the other side of each extends obliquely toward the outer ring (42) and the inner ring (41) of the flame tube, respectively, so as to guide the fuel injected by the fuel nozzle (30) and control the fuel cone angle of atomization.

8. The dual-vortex flow field recirculation combustion chamber according to claim 2, characterized in that, The outflow side of the inner ring (41) of the flame tube and the outflow side of the outer ring (42) of the flame tube are fixedly connected to the combustion chamber casing (10) as a whole.

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