An annular fluid oscillator nozzle combustion chamber

Abstract

The present invention provides an annular fluid oscillator nozzle combustion chamber, comprising an outer casing of a combustion chamber, a flame tube installed inside the outer casing of the combustion chamber, an annular oscillation generating device installed on the side of the flame tube, an inner casing of the combustion chamber installed inside the flame tube, an oil delivery device connected to the annular oscillation generating device, and a diffuser fixedly installed on the outer casing of the combustion chamber. The fuel of the present invention is accelerated through the cross-section of the inlet contraction section, flows through the cavity and the fluid separation device, and through the Coanda effect, the fuel in the cavity periodically flows into the reflux channel located around the cavity, and generates annular periodic disturbances on the fuel flowing into the cavity from the inlet convergence section of the annular fluid oscillation device, thereby causing the fuel to deviate axially and be ejected along the fluid deflection section to the outlet expansion section, realizing a large range of periodic directional changes. The speed direction of the periodic change of the fuel enables the fuel to be more fully mixed with the air, thereby improving the uniformity of the fuel atomization and making the fuel burn better.

Description

Technical Field

[0001] The present invention relates to the technical field of aviation engines and gas turbines, and in particular to an annular fluid oscillator nozzle combustion chamber. Background Art

[0002] The combustion chamber plays a vital role in aircraft engines and gas turbines and is known as the "heart of the engine." In the combustion chamber, fuel and air are fully mixed and then burned. The high-temperature and high-pressure combustion gas generated drives the turbine to work, becoming the main energy source for the engine to generate thrust.

[0003] With the continuous advancement of aircraft engine and gas turbine technology, the requirements for combustion chamber combustion efficiency are also increasing. For high-power equipment, a small increase in efficiency can often bring huge economic benefits. Therefore, the research and development of high-performance combustors faces a series of technical challenges: the stability of fuel combustion must be achieved within a diverse stable operating range in the combustor to ensure engine reliability and safety; reducing the polluting exhaust gas generated during the combustion process is an important goal for achieving sustainable development; on the premise of meeting combustion requirements, it becomes particularly critical to improve the atomization effect of the fuel and the degree of mixing of the fuel and air to further improve combustion efficiency.

[0004] At present, centrifugal nozzles are commonly used in aircraft engine combustion chambers. This design can spray fuel into the flame tube cavity in a conical manner, promoting the breakup and atomization of the fuel liquid film. However, it also has disadvantages. Fuel atomization mainly relies on centrifugal force. At low flow rates, the rotation speed is insufficient, resulting in increased droplet size and uneven atomization, which affects combustion efficiency. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a ring fluid oscillator nozzle combustion chamber to replace the flame structure of the traditional centrifugal nozzle. The ring oscillation generating device utilizes the Coanda effect to spontaneously generate periodic oscillations. By changing the upstream pressure, it can achieve self-regulation of the atomization frequency, and utilize the oscillating shearing effect to atomize the fuel. The fluid is sprayed in the outlet expansion section to form a periodically changing fluid, so that fuel droplets of more uniform size can perfectly cover most areas of the flame tube head, further improving the overall performance of the combustion chamber.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A ring fluid oscillator nozzle combustion chamber includes an outer casing of the combustion chamber, a flame tube installed inside the outer casing of the combustion chamber, a ring oscillation generating device installed on the side of the flame tube, an inner casing of the combustion chamber installed inside the flame tube, an oil delivery device connected to the ring oscillation generating device, and a diffuser fixedly installed on the outer casing of the combustion chamber.

[0008] Preferably, the flame tube includes a flame tube outer shell fixedly mounted on the inner wall of the outer casing of the combustion chamber and a flame tube inner shell fixedly mounted inside the flame tube outer shell. At least one first jet hole is provided at one end of the flame tube outer shell, and the front sections of the flame tube outer shell and the flame tube inner shell are each provided with at least one second jet hole. The rear sections of the flame tube outer shell and the flame tube inner shell are provided with at least one group of cooling holes along the axial direction of the flame tube. The flame tube also includes a flame tube support plate fixedly mounted on the flame tube inner shell, and the combustion chamber casing is fixedly mounted on the flame tube support plate.

[0009] Furthermore, the ratio of the distance from the center of the second jet hole to one end of the flame tube outer shell to the total length of the flame tube is 0.2 to 0.25, the ratio of the arrangement range of the cooling holes to the total length of the flame tube is 0.6 to 0.7, and the aspect ratio of the flame tube is 1.2 to 1.5.

[0010] Furthermore, the number of the annular oscillation generating device is at least one, the position of at least one of the annular oscillation generating devices corresponds one-to-one to the position of at least one first jet hole, and two adjacent annular oscillation generating devices form a certain angle with each other.

[0011] Furthermore, each of the annular oscillation generating devices includes an outer shell, a fluid deflection section is fixedly installed on one end of the outer shell, an outlet expansion section is fixedly installed on the end of the fluid deflection section away from the outer shell, the outlet expansion section passes through the corresponding first jet hole and extends into the flame tube, an inlet contraction section is fixedly installed on the other end of the outer shell, a threaded section is fixedly installed on the end of the inlet contraction section away from the outer shell, a cavity is opened inside the outer shell, a support column is fixedly installed on the inner wall of the outer shell, a fluid separation device is provided inside the cavity, the fluid separation device is fixedly connected to the support column, and a reflux channel is formed between the fluid separation device and the inner wall of the outer shell.

[0012] Furthermore, the oil delivery device includes an annular oil pipe, a main oil pipe fixedly installed on the annular oil pipe, and an inlet mounting hole opened on the annular oil pipe.

[0013] Furthermore, the inlet mounting hole is a threaded hole, and the number of inlet mounting holes is at least one, at least one threaded segment is threadedly installed in a one-to-one correspondence with at least one of the inlet mounting holes, the annular oil pipe is connected to the annular oscillation generating device and the main oil pipe, and the installation angle between the main oil pipe and the annular oscillation generating device is 90° to 150°.

[0014] Furthermore, at least one main oil pipe is provided, and at least one main oil pipe is evenly distributed circumferentially installed on the annular oil pipe.

[0015] Furthermore, the angle of the inlet contraction section is 50° to 70°, the angle of the outlet expansion section is 70° to 80°, and the ratio of the outlet cross-sectional diameter of the outlet expansion section to the radius of the flame tube cross-sectional area perpendicular to the axis is 0.03 to 0.1.

[0016] Furthermore, at least one main oil pipe mounting hole is provided on the outer casing of the combustion chamber, and the position of at least one main oil pipe mounting hole corresponds one-to-one to the position of at least one main oil pipe. One end of at least one main oil pipe away from the annular oil pipe passes through the main oil pipe mounting hole at the corresponding position and extends to the outside of the outer casing of the combustion chamber.

[0017] Beneficial effects of the present invention:

[0018] Compared with ordinary centrifugal nozzles, the fuel of the present invention is accelerated through the cross-section of the inlet contraction section, flows through the cavity and the fluid separation device, and through the Coanda effect, the fuel in the cavity periodically flows into the reflux channel located around the cavity, and generates annular periodic disturbances on the fuel flowing into the cavity from the inlet convergence section of the annular fluid oscillation device, thereby causing the fuel to deviate axially and be ejected along the fluid deflection section to the outlet expansion section, realizing large-scale periodic direction changes. The speed direction of the periodic change of the fuel enables the fuel to be more fully mixed with the air, improves the uniformity of the fuel atomization, and enables the fuel to burn better; a certain angle is formed between the two adjacent annular oscillation generating devices, so that the jet ranges of the two adjacent devices partially overlap with each other, playing a role of cross-flame, making the fuel combustion range wider and improving the gas combustion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a three-dimensional cross-sectional structural schematic diagram of the present invention.

[0021] Figure 2 It is a three-dimensional schematic diagram of the ring oscillation generating device of the present invention.

[0022] Figure 3 Schematic diagram of the structure of the ring oscillation generating device of the present invention, wherein the left side is a main view of the ring oscillation generating device and the right side is a cross-sectional view.

[0023] Figure 4 It is a three-dimensional schematic diagram of the oil delivery device of the present invention.

[0024] Figure 5 It is a three-dimensional cross-sectional schematic diagram of the flame tube of the present invention.

[0025] Explanation of the symbols in the figure: 1. Annular oscillation generating device; 2. Oil delivery device; 3. Flame tube; 4. Combustion chamber outer casing; 5. Combustion chamber inner casing; 6. Diffuser; 7. Main oil pipe mounting hole; 101. Threaded section; 102. Inlet contraction section; 103. Cavity; 104. Fluid deflection section; 105. Outlet expansion section; 106. Return channel; 107. Outer casing; 108. Support column; 109. Fluid separation device; 201. Main oil pipe; 202. Annular oil pipe; 203. Inlet mounting hole; 301. First jet hole; 302. Second jet hole; 303. Cooling hole; 304. Flame tube outer casing; 305. Flame tube inner casing; 306. Flame tube support plate. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0028] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the present invention. As used in the specification and appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0029] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0030] Example

[0031] See also Figure 1-5As shown, a ring-shaped fluid oscillator nozzle combustion chamber includes an outer casing 4 of the combustion chamber, a flame tube 3 installed inside the outer casing 4 of the combustion chamber, a ring-shaped oscillation generating device 1 installed on the side of the flame tube 3, an inner casing 5 of the combustion chamber installed inside the flame tube 3, an oil delivery device 2 connected to the ring-shaped oscillation generating device 1, and a diffuser 6 fixedly installed on the outer casing 4 of the combustion chamber. The diffuser 6, the inner casing 5 of the combustion chamber, the outer casing 4 of the combustion chamber, the flame tube 3, the oil delivery device 2 and the ring-shaped oscillation generating device 1 together constitute an annular fluid oscillation nozzle combustion chamber, and the outer casing 4 of the combustion chamber and the inner casing 5 of the combustion chamber together constitute a combustion chamber shell.

[0032] The flame tube 3 includes a flame tube outer shell 304 fixedly mounted on the inner wall of the combustion chamber outer casing 4 and a flame tube inner shell 305 fixedly mounted inside the flame tube outer shell 304. One end of the flame tube outer shell 304 is provided with at least one first jet hole 301. The front sections of the flame tube outer shell 304 and the flame tube inner shell 305 are each provided with at least one second jet hole 302. The rear sections of the flame tube outer shell 304 and the flame tube inner shell 305 are provided with at least one group of cooling holes 303 along the axial direction of the flame tube 3. The flame tube 3 also includes a flame tube support plate 306 fixedly mounted on the flame tube inner shell 305. The combustion chamber inner casing 5 is fixedly mounted on the flame tube support plate 306.

[0033] The area enclosed by the liner outer shell 304 and the liner inner shell 305 is the combustion area.

[0034] In this embodiment, the number of the first jet holes 301 is preferably 8 to 16. The positions of the first jet holes 301 correspond one-to-one to the positions of the outlet expansion section 105 of the ring oscillation generating device 1. The first jet holes 301 are used for atomizing and injecting fuel.

[0035] In this embodiment, the number of the second jet holes 302 is preferably 16 to 32, and the second jet holes 302 are evenly distributed circumferentially on the flame tube outer shell 304 and the flame tube inner shell 305, and the positions of the second jet holes 302 opened on the flame tube outer shell 304 correspond to the positions of the second jet holes 302 opened on the flame tube inner shell 305, and the second jet holes 302 are used for air to enter the flame tube 3.

[0036] In this embodiment, the cooling holes 303 are preferably arranged in 8 to 10 groups along the axial direction of the flame tube 3, with a number of 32 to 48. The cooling holes 303 are evenly distributed circumferentially on the flame tube outer shell 304 and the flame tube inner shell 305, and the positions of the cooling holes 303 opened on the flame tube outer shell 304 correspond to the positions of the cooling holes 303 opened on the flame tube inner shell 305. The cooling holes 303 are used for air to enter the flame tube 3 and cool the flame tube 3.

[0037] The cooling holes are evenly distributed on the inner wall and outer wall of the flame tube in the circumferential direction. The ratio of the distance from the center of the second jet hole 302 to one end of the flame tube shell 304 to the total length of the flame tube 3 is 0.2-0.25. The ratio of the arrangement range of the cooling holes 303 to the total length of the flame tube 3 is 0.6-0.7. The aspect ratio of the flame tube 3 is 1.2-1.5.

[0038] There is at least one ring oscillation generating device 1 , and the position of at least one ring oscillation generating device 1 corresponds to the position of at least one first jet hole 301 . Two adjacent ring oscillation generating devices 1 form a certain angle with each other, and the ring oscillation generating device 1 is made of metal.

[0039] In this embodiment, the number of the annular oscillation generating devices 1 is preferably 8 to 16, and the annular oscillation generating devices 1 are evenly distributed on the annular oil pipe 202 .

[0040] Each ring oscillation generating device 1 includes a shell 107, a fluid deflection section 104 is fixedly mounted on one end of the shell 107, an outlet expansion section 105 is fixedly mounted on the end of the fluid deflection section 104 away from the shell 107, the outlet expansion section 105 passes through the corresponding first jet hole 301 and extends into the flame tube 3, an inlet contraction section 102 is fixedly mounted on the other end of the shell 107, a threaded section 101 is fixedly mounted on the end of the inlet contraction section 102 away from the shell 107, a cavity 103 is defined inside the shell 107, a support column 108 is fixedly mounted on the inner wall of the shell 107, a fluid separation device 109 is provided inside the cavity 103, the fluid separation device 109 is fixedly connected to the support column 108, and a reflux channel 106 is formed between the fluid separation device 109 and the inner wall of the shell 107;

[0041] The oil flow direction in the cavity 103 of the ring oscillation generating device 1 is axial, and the direction of the oil flow in the return channel 106 is opposite to that of the oil flow in the cavity 103 of the ring oscillation generating device 1 .

[0042] The oil delivery device 2 includes an annular oil pipe 202 , a main oil pipe 201 fixedly mounted on the annular oil pipe 202 , and an inlet mounting hole 203 opened on the annular oil pipe 202 ; the engine's oil supply system is connected to the main oil pipe 201 and delivers oil to the annular oil pipe 202 .

[0043] The inlet mounting hole 203 is a threaded hole, and there is at least one inlet mounting hole 203. At least one threaded segment 101 is threadedly mounted in a one-to-one correspondence with at least one inlet mounting hole 203. The annular oscillation generating device 1 is mounted on the annular oil pipe 202 through the threaded segment 101 and the inlet mounting hole 203. The annular oil pipe 202 is connected to both the annular oscillation generating device 1 and the main oil pipe 201. The installation angle between the main oil pipe 201 and the annular oscillation generating device 1 is 90° to 150°.

[0044] In this embodiment, the annular oil pipe 202 is a circular metal pipe, and the number of the annular oil pipe 202 is one.

[0045] At least one main oil pipe 201 is provided, and at least one main oil pipe 201 is evenly distributed circumferentially on the annular oil pipe 202 .

[0046] In this embodiment, the main oil pipe 201 is a bendable metal pipe, which is connected to the engine's fuel supply system to transport the fuel into the oil delivery device 2; the number of main oil pipes 201 is preferably 1 to 3, and the main oil pipes 201 are evenly distributed circumferentially on the annular oil pipe 202.

[0047] The included angle of the inlet contraction section 102 is 50° to 70°, the included angle of the outlet expansion section 105 is 70° to 80°, and the ratio of the outlet cross-sectional diameter of the outlet expansion section 105 to the radius of the cross-sectional area of ​​the flame tube 3 perpendicular to the axis is 0.03 to 0.1;

[0048] At least one main oil pipe mounting hole 7 is provided on the combustion chamber outer casing 4. The position of the at least one main oil pipe mounting hole 7 corresponds one-to-one to the position of the at least one main oil pipe 201. One end of the at least one main oil pipe 201 away from the annular oil pipe 202 passes through the main oil pipe mounting hole 7 at the corresponding position and extends to the outside of the combustion chamber outer casing 4.

[0049] Working principle: The fuel enters the annular oil pipe 202 through the main oil pipe 201, and flows into each annular oscillation generating device 1 from the annular oil pipe 202. The fuel enters the cavity 103 of the annular oscillation generating device 1 through the inlet contraction section 102, and the fuel is accelerated through the cross section of the inlet contraction section 102 during the process of passing through the inlet contraction section 102, and flows into the cavity 103. Under the action of the Coanda effect, part of the fuel flows into the return channel 106 along the fluid separation device 109 and flows out from the outlet of the return channel 106 at the inlet end, causing disturbance to the fuel entering the cavity 103, changing the flow direction of the fuel to a certain extent, causing the fuel to flow into the counter-reflux inlet, and then causing disturbance to the fuel flowing into the cavity 103 in the opposite direction to the previous one, so that the speed direction of the ejected fuel changes periodically within a certain range. The change can effectively improve the uniformity of fuel atomization and the degree of mixing of fuel and air, which is beneficial to the full combustion of fuel and the reduction of exhaust gas emissions; at the same time, since the two adjacent annular oscillation generating devices 1 form a certain angle with each other, the injection ranges of the annular oscillation generating devices 1 overlap, which plays a role in flame linkage, so that the flame propagates rapidly in the cavity of the flame tube 3, thereby improving the combustion efficiency of the gas; the positions of the second jet holes 302 arranged on the flame tube outer shell 304 and the flame tube inner shell 305 correspond one to one, so that the air entering the flame tube 3 cavity from the combustion chamber impacts each other, reducing the air flow velocity in the flame tube 3 cavity and generating a vortex structure, thereby improving the mixing efficiency of fuel and air; cooling holes 303 are provided on the flame tube outer shell 304 and the flame tube inner shell 305 for balancing the temperature distribution in the flame tube 3, thereby improving the combustion efficiency and reducing the emission of pollutants.

[0050] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. An annular fluid oscillator nozzle combustion chamber, characterized in that: The invention comprises a combustion chamber outer casing (4), a flame tube (3) installed inside the combustion chamber outer casing (4), a ring oscillation generating device (1) installed on the side of the flame tube (3), a combustion chamber inner casing (5) installed inside the flame tube (3), an oil delivery device (2) connected to the ring oscillation generating device (1), and a diffuser (6) fixedly installed on the combustion chamber outer casing (4); The flame tube (3) comprises a flame tube outer shell (304) fixedly mounted on the inner wall of the combustion chamber outer casing (4) and a flame tube inner shell (305) fixedly mounted inside the flame tube outer shell (304), one end of the flame tube outer shell (304) is provided with at least one first jet hole (301), the front sections of the flame tube outer shell (304) and the flame tube inner shell (305) are both provided with at least one second jet hole (302), the rear sections of the flame tube outer shell (304) and the flame tube inner shell (305) are provided with at least one group of cooling holes (303) along the axial direction of the flame tube (3), the flame tube (3) further comprises a flame tube support plate (306) fixedly mounted on the flame tube inner shell (305), and the combustion chamber inner casing (5) is fixedly mounted on the flame tube support plate (306); Each of the annular oscillation generating devices (1) comprises a housing (107), a fluid deflection section (104) is fixedly mounted on one end of the housing (107), an outlet expansion section (105) is fixedly mounted on the end of the fluid deflection section (104) away from the housing (107), the outlet expansion section (105) passes through the corresponding first jet hole (301) and extends into the flame tube (3), and an inlet contraction section (102) is fixedly mounted on the other end of the housing (107), the inlet contraction section (105) is fixedly mounted on the other end of the housing (107), and the outlet contraction section (105) is fixedly mounted on the other end of the housing (107). 02) A threaded section (101) is fixedly installed at one end away from the shell (107), a cavity (103) is provided inside the shell (107), a support column (108) is fixedly installed on the inner wall of the shell (107), a fluid separation device (109) is provided inside the cavity (103), the fluid separation device (109) is fixedly connected to the support column (108), and a reflux channel (106) is formed between the fluid separation device (109) and the inner wall of the shell (107).

2. The annular fluid oscillator nozzle combustion chamber according to claim 1, characterized in that: The ratio of the distance from the center of the second jet hole (302) to one end of the flame tube shell (304) to the total length of the flame tube (3) is 0.2 to 0.25, the ratio of the arrangement range of the cooling hole (303) to the total length of the flame tube (3) is 0.6 to 0.7, and the aspect ratio of the flame tube (3) is 1.2 to 1.

5.

3. The annular fluid oscillator nozzle combustion chamber according to claim 1, characterized in that: The number of the annular oscillation generating device (1) is at least one, the position of at least one of the annular oscillation generating devices (1) corresponds one-to-one to the position of at least one first jet hole (301), and two adjacent annular oscillation generating devices (1) form a certain angle with each other.

4. The annular fluid oscillator nozzle combustion chamber according to claim 1, characterized in that: The oil delivery device (2) comprises an annular oil pipe (202), a main oil pipe (201) fixedly mounted on the annular oil pipe (202), and an inlet mounting hole (203) opened on the annular oil pipe (202).

5. The annular fluid oscillator nozzle combustion chamber according to claim 4, characterized in that: The inlet mounting hole (203) is a threaded hole, and the number of the inlet mounting hole (203) is at least one. At least one threaded section (101) is threadedly mounted in a one-to-one correspondence with at least one of the inlet mounting holes (203). The annular oil pipe (202) is connected to the annular oscillation generating device (1) and the main oil pipe (201). The installation angle between the main oil pipe (201) and the annular oscillation generating device (1) is 90° to 150°.

6. The annular fluid oscillator nozzle combustion chamber according to claim 5, characterized in that: At least one main oil pipe (201) is provided, and at least one main oil pipe (201) is evenly distributed circumferentially and installed on the annular oil pipe (202).

7. The annular fluid oscillator nozzle combustion chamber according to claim 1, characterized in that: The included angle of the inlet contraction section (102) is 50° to 70°, the included angle of the outlet expansion section (105) is 70° to 80°, and the ratio of the outlet cross-sectional diameter of the outlet expansion section (105) to the radius of the cross-sectional area of ​​the flame tube (3) perpendicular to the axis is 0.03 to 0.

1.

8. The annular fluid oscillator nozzle combustion chamber according to claim 4, characterized in that: At least one main oil pipe mounting hole (7) is provided on the combustion chamber outer casing (4), the position of at least one main oil pipe mounting hole (7) corresponds to the position of at least one main oil pipe (201), and one end of at least one main oil pipe (201) away from the annular oil pipe (202) passes through the main oil pipe mounting hole (7) at the corresponding position and extends to the outside of the combustion chamber outer casing (4).

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