An oil-gas separation integrated flame stabilizer system and a variable cycle engine

Abstract

The present invention provides an integrated flame stabilizer system with oil-gas separation, which includes: a pilot injection rod, a filling injection rod, and a flame stabilizer. In the non-afterburning state, the inside of the stabilizer outer casing is filled with cooling gas; in the afterburning state, the inside of the stabilizer inner casing is filled with pilot fuel, and the other areas of the stabilizer outer casing are filled with cooling gas, thereby solving the problems of ablation and coking of the injection rod and the flame stabilizer. The pilot fuel is injected reversely at the leading edge of the stabilizer inner casing, and the uniformity of the pilot fuel in the radial direction is improved by means of splash-proof atomization. Subsequently, it leaves the flame stabilizer from the pilot fuel circuit and is evenly distributed near the recirculation zone, thereby ensuring the stable combustion of the flame stabilizer. The filling fuel is injected laterally and evenly distributed in the non-blocked area of the afterburner combustion chamber, thereby ensuring the efficient combustion of the flame stabilizer. The present invention also provides a variable cycle engine having the flame stabilizer system.

Description

Technical Field

[0001] The present invention belongs to the field of aeroengines, relates to a variable cycle engine, and particularly relates to an integrated fuel-gas separation type flame stabilizer system. Background Art

[0002] A variable cycle engine (VCE) is a main development direction of future military aeroengines. Through the mutual cooperation among multiple ducts, it realizes the mutual switching of different working modes, thereby effectively expanding the flight envelope of a fighter and improving the working performance of the engine at different altitudes and speed points within the flight envelope.

[0003] With the continuous increase in the flight altitude and speed of a fighter, the inlet temperature and speed of the afterburner increase significantly, which introduces new technical difficulties: First, the inlet temperature of the inner duct in the afterburner is extremely high, exceeding the tolerance temperature of nickel-based single crystal alloys, which will cause ablation and coking problems of the fuel injection rod and the flame stabilizer, affecting the engine performance and safety; Second, to avoid premature auto-ignition of aviation kerosene, the fuel injection rod needs to be installed inside the flame stabilizer, but this will result in too short a distance between the fuel nozzle and the recirculation zone at the trailing edge of the flame stabilizer, reducing the fuel evaporation and mixing time, making it difficult for the flame stabilizer to stabilize the flame and resulting in low combustion efficiency. Summary of the Invention

[0004] In view of this, the present invention provides an integrated fuel-gas separation type flame stabilizer system, which can integrally achieve fuel injection, flame stabilization and cooling, thereby effectively solving the problems of difficult flame stabilization and low combustion efficiency of the flame stabilizer in the afterburner of a variable cycle engine, as well as the ablation and coking problems of the fuel injection rod and the flame stabilizer.

[0005] In one aspect of the present invention, there is provided an integrated fuel-gas separation type flame stabilizer system, characterized by comprising:

[0006] A flame stabilizer, which includes a stabilizer outer shell, a stabilizer inner shell disposed inside the stabilizer outer shell, and a duty oil passage that communicates the outside of the stabilizer outer shell with the inside of the stabilizer inner shell;

[0007] A duty fuel injection rod, installed inside the stabilizer inner shell, and injecting duty fuel to the outside of the flame stabilizer through the duty oil passage;

[0008] A filling fuel injection rod, installed inside the stabilizer outer shell and behind the stabilizer inner shell, and injecting filling fuel to the outside of the flame stabilizer through filling drain holes provided on the side wall of the stabilizer outer shell; and

[0009] The cooling air inlet pipe is capable of introducing cooling air into the interior of the stabilizer outer casing, wherein a first portion of the cooling air passes through the filling injection rod and is discharged from the filling oil drain hole out of the stabilizer outer casing, and a second portion of the cooling air enters the interior of the stabilizer inner casing through the air holes at the trailing edge of the stabilizer inner casing to cool the duty injection rod.

[0010] Preferably, the flame stabilizer further includes a solid partition. The stabilizer inner casing is disposed in the front region inside the stabilizer outer casing. The cooling air inlet pipe communicates with the rear region of the stabilizer outer casing. The solid partition is disposed in the middle region inside the stabilizer outer casing and behind the filling injection rod.

[0011] Wherein, one of the two side walls in the radial direction of the stabilizer outer casing is spaced from the solid partition to form a first air flow channel, and the other side wall is attached to the solid partition and communicates with the cooling air inlet pipe.

[0012] Preferably, a plurality of the duty oil passages are spaced along the radial direction of the stabilizer outer casing, so as to enclose a second air flow channel between two adjacent ones of the duty oil passages, the stabilizer inner casing and the stabilizer outer casing.

[0013] Wherein, the flame stabilizer further includes a front impact partition disposed on the front side of the stabilizer inner casing. The front impact partition is provided with a plurality of impact air holes. A third portion of the cooling air passes through the first air flow channel, the second air flow channel and the impact air holes on the front impact partition, and impacts the inner side of the leading edge of the stabilizer outer casing for cooling.

[0014] Preferably, the flame stabilizer further includes a rear impact partition disposed behind the cooling air inlet pipe. The rear impact partition is provided with a plurality of impact air holes. A fourth portion of the cooling air passes through the impact air holes on the rear impact partition and impacts the inner side of the trailing edge of the stabilizer outer casing for cooling.

[0015] Preferably, air film holes are respectively provided at the leading edge and the trailing edge positions of the stabilizer outer casing, so that the third portion and the fourth portion of the cooling air respectively pass through the air film holes to form air film cooling at the leading edge and the trailing edge of the stabilizer outer casing.

[0016] And, air film holes are also provided at the position of the side wall of the stabilizer outer casing close to the filling oil drain hole, so as to at least partially divert the first portion of the cooling air to form air film cooling on the side wall of the stabilizer outer casing.

[0017] Preferably, the pilot injection rod is provided with a plurality of direct injection nozzles configured to inject fuel from the rear to the front, so that the fuel impacts the leading edge of the inner housing of the stabilizer and then is discharged from the flame stabilizer through the inner housing of the stabilizer, the pilot oil passage and the outer housing of the stabilizer.

[0018] Preferably, the total passage area of the plurality of pilot oil passages is larger than the total area of the plurality of direct injection nozzles.

[0019] Preferably, the filling injection rod is provided with a plurality of direct injection or fan-shaped filling fuel nozzles, and the positions of the plurality of filling fuel nozzles are matched with the positions of the plurality of filling drain holes, so as to ensure that the filling fuel is discharged from the flame stabilizer.

[0020] In another aspect of the present invention, there is provided a variable cycle engine, characterized in that it includes the oil-gas separation integrated flame stabilizer system as described in any one of the previous embodiments.

[0021] Preferably, the flame stabilizer is arranged inside the trailing edge of the splitter ring or outside the center cone of the afterburner of the variable cycle engine, and the cooling air inlet pipe is configured to introduce cooling air from the outer bypass duct or the core fan.

[0022] Based on this, each embodiment of the present invention has at least one of the following beneficial technical effects:

[0023] The present invention constructs the flame stabilizer into a double-layer structure composed of an outer housing of the stabilizer and an inner housing of the stabilizer, accommodates the pilot injection rod inside the inner housing of the stabilizer, and accommodates the filling injection rod between the outer housing of the stabilizer and the inner housing of the stabilizer. Thus, by introducing cooling air into the inside of the outer housing of the stabilizer and designing corresponding cooling flow paths, the pilot injection rod and the filling injection rod can be fully cooled.

[0024] The present invention improves the fuel atomization and mixing effect by making the pilot injection rod inject reversely and impact the inner leading edge of the inner housing of the stabilizer, and simultaneously achieves two technical effects of higher flame stability and better flame combustion efficiency by precisely controlling the respective injection paths of the pilot fuel and the filling fuel.

[0025] The present invention constructs the cooling flow paths inside the flame stabilizer by using structures such as the front impact partition, the rear impact partition, and the solid partition, so that the cooling air is divided into strands to cool different important parts, and uses the film holes distributed in the leading edge, middle and trailing edge regions of the flame stabilizer to make the cooling air inside the flame stabilizer flow out and form a corresponding film cooling structure on the outer surface of the flame stabilizer. Description of the Drawings

[0026] The accompanying drawings are used to provide a further understanding of the technical solution of the present application, and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application, but do not constitute a limitation to the technical solution of the present application.

[0027] Figure 1 FIG. 4 is a schematic three-dimensional structure view of the oil-gas separation integrated flame stabilizer system provided by the present invention along a circumferential section perpendicular to the vertical direction;

[0028] Figure 2 FIG. 5 is a schematic three-dimensional structure view of the oil-gas separation integrated flame stabilizer system provided by the present invention along a radial section perpendicular to the vertical direction;

[0029] Reference numerals:

[0030] 1 - Flame stabilizer, 11 - Stabilizer outer housing, 12 - Cooling air inlet pipe, 13 - Solid partition, 14 - Front impact partition, 15 - Rear impact partition, 16 - Stabilizer inner housing, 17 - Pilot oil circuit, 18 - Filling and draining hole, 19 - Air film hole;

[0031] 2 - Pilot injection rod, 21 - Direct injection nozzle;

[0032] 3 - Filling injection rod, 31 - Filling fuel nozzle;

[0033] a - First air flow channel, b - Second air flow channel. Detailed implementation manners

[0034] Hereinafter, various exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and does not impose any limitation on the present invention and its application or use. The present utility model can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present invention clear and complete, and to fully convey the scope of the present invention to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangement of the components and steps set forth in these embodiments should be construed as merely exemplary and not as a limitation.

[0035] As Figure 1-2 shown, in one aspect of the present invention, there is provided an oil-gas separation integrated flame stabilizer system, which includes a flame stabilizer 1, a pilot injection rod 2, a filling injection rod 3 and a cooling air inlet pipe 12. Among them, the flame stabilizer 1 includes a stabilizer outer housing 11, a stabilizer inner housing 16 disposed inside the stabilizer outer housing 11, and a pilot oil circuit 17 that communicates the outside of the stabilizer outer housing 11 with the inside of the stabilizer inner housing 16.

[0036] Based on the structure of the flame stabilizer 1, the pilot injection rod 2 is installed inside the inner housing 16 of the stabilizer and sprays pilot fuel to the outside of the flame stabilizer 1 through the pilot oil passage 17; the filling injection rod 3 is installed inside the outer housing 1 of the stabilizer and is located at the rear side of the inner housing 16 of the stabilizer, and sprays filling fuel to the outside of the flame stabilizer 1 through the filling drain holes 18 provided on the side wall of the outer housing 11 of the stabilizer; and the cooling air inlet pipe 12 can introduce cooling air into the inside of the outer housing 11 of the stabilizer, wherein the first part of the cooling air flows through the filling injection rod 3 and discharges from the filling drain holes 18 out of the outer housing 1 of the stabilizer, and the second part of the cooling air enters the inside of the inner housing 16 of the stabilizer through the air holes at the trailing edge of the inner housing 16 of the stabilizer to cool the pilot injection rod 2.

[0037] Thus, in the non-afterburning state, the inside of the outer housing 11 of the stabilizer is filled with cooling air, and in the afterburning state, the inside of the inner housing 16 of the stabilizer is filled with pilot fuel, and the other areas of the outer housing 11 of the stabilizer are filled with cooling air, so as to solve the problems of ablation and coking of the injection rod and the flame stabilizer while ensuring a stable ignition source provided by the flame stabilizer.

[0038] Preferably, the flame stabilizer 1 further includes a solid partition 13, the inner housing 16 of the stabilizer is arranged in the front area inside the outer housing 11 of the stabilizer, the cooling air inlet pipe 12 communicates with the rear area of the outer housing 11 of the stabilizer, and the solid partition 13 is arranged in the middle area inside the outer housing 11 of the stabilizer and is located at the rear side of the filling injection rod 3; wherein, one of the two side walls in the radial direction of the outer housing 11 of the stabilizer is arranged at an interval from the solid partition 13 to form a first air flow channel a, and the other side wall is attached to the solid partition 13 and communicates with the cooling air inlet pipe 12.

[0039] In the present invention, the inner housing 16 of the stabilizer, the solid partition 13 and the cooling air inlet pipe 12 are respectively arranged in the front, middle and rear areas of the outer housing 11 of the stabilizer, and the first air flow channel a is used to form a tortuous flow path of the cooling air from the rear to the front inside the flame stabilizer, so that the cooling air can flow more fully to each part of the flame stabilizer and flow against the temperature gradient of the flame stabilizer from the rear to the front to ensure the cooling effects of both the front and rear parts of the flame stabilizer.

[0040] Preferably, a plurality of pilot oil passages 17 are arranged at intervals in the radial direction of the outer housing 11 of the stabilizer, so as to enclose a second air flow channel b between two adjacent pilot oil passages 17, the inner housing 16 of the stabilizer and the outer housing 11 of the stabilizer; wherein, the flame stabilizer 1 further includes a front impact partition 14 arranged on the front side of the inner housing 16 of the stabilizer, and a plurality of impact air holes are provided on the front impact partition 14, and the third part of the cooling air impacts the inner side of the leading edge of the outer housing 11 of the stabilizer for cooling through the first air flow channel a, the second air flow channel b and the impact air holes on the front impact partition 14.

[0041] The duty oil circuit 17 is a pipeline structure, which is connected between the inner housing 16 of the stabilizer and the outer housing 11 of the stabilizer, so that the fuel ejected by the duty fuel injection rod 2 can reach the outside of the outer housing 11 of the stabilizer from the inside of the inner housing 16 of the stabilizer through the duty oil circuit 17. Moreover, a plurality of duty oil circuits 17 are arranged at intervals, so as not to completely block the gap between the inner housing 16 of the stabilizer and the outer housing 11 of the stabilizer, and a second air flow channel b is enclosed between two adjacent duty oil circuits 17, the inner housing 16 of the stabilizer and the outer housing 11 of the stabilizer.

[0042] Through this second air flow channel b, the third part of the cooling air can reach the front area inside the outer housing 11 of the stabilizer, and form an impact cooling air flow that impacts the inner side of the leading edge of the outer housing 11 of the stabilizer through the impact air holes on the front impact partition 14. Moreover, a plurality of film holes 19 are provided at the leading edge of the outer housing 11 of the stabilizer. Therefore, after the third part of the cooling air impacts the leading edge of the outer housing 11 of the stabilizer, it will further flow out of the flame stabilizer 1 along the plurality of film holes 19 and form film cooling outside the leading edge of the outer housing 11 of the stabilizer. Thus, the cooling of the leading edge of the outer housing 11 of the stabilizer in direct contact with the high-temperature oncoming flow is realized by the internal impact cooling and the external film cooling together.

[0043] Preferably, the flame stabilizer 1 further includes a rear impact partition 15 arranged at the rear side of the cooling air inlet pipe 12. A plurality of impact air holes are provided on the rear impact partition 15, and the fourth part of the cooling air impacts the inner side of the trailing edge of the outer housing 11 of the stabilizer through the impact air holes on the rear impact partition 15 for cooling. Correspondingly, a plurality of film holes 19 are also provided at the trailing edge of the outer housing 11 of the stabilizer. Therefore, after the fourth part of the cooling air impacts the trailing edge of the outer housing 11 of the stabilizer, it will further flow out of the flame stabilizer 1 along the plurality of film holes 19 and form film cooling outside the trailing edge of the outer housing 11 of the stabilizer. Thus, the cooling of the trailing edge of the outer housing 11 of the stabilizer is realized by the internal impact cooling and the external film cooling together.

[0044] Preferably, the outer housing 11 of the stabilizer is provided with film holes 19 at a position on the side wall close to the filling and draining hole, so as to at least partially divert the first part of the cooling air and form film cooling on the side wall of the outer housing 11 of the stabilizer.

[0045] Preferably, the duty fuel injection rod 2 is provided with a plurality of direct injection nozzles 21 configured to inject fuel from the rear to the front, so that the fuel impacts the leading edge of the inner housing 16 of the stabilizer and then is discharged from the flame stabilizer 1 through the inner housing 16 of the stabilizer, the duty oil circuit 17 and the outer housing 11 of the stabilizer.

[0046] The above-mentioned pilot fuel is evenly distributed radially (in the same direction as the fuel injection rod), and then leaves the flame stabilizer 1 from the pilot fuel passage 17. The pilot fuel is injected reversely at the leading edge of the inner shell of the stabilizer, and the uniformity of the pilot fuel in the radial direction is improved by means of splash-proof atomization. Then, the pilot fuel leaves the flame stabilizer from the pilot fuel passage and is evenly distributed near the recirculation zone, thus ensuring the stable combustion of the flame stabilizer.

[0047] Preferably, the total passage area of the multiple pilot fuel passages 17 is larger than the total area of the multiple direct-injection nozzles 21. Since the passage area of the pilot fuel passage is much larger than the area of the direct-injection nozzle, it can be known that the velocity of the pilot fuel leaving the flame stabilizer is smaller and the fuel penetration depth is lower. Therefore, it is evenly distributed in the circumferential direction near the trailing-edge recirculation zone of the flame stabilizer, thus ensuring that this integrated system has excellent flame stabilization performance.

[0048] Preferably, the filling fuel injection rod 3 is provided with multiple direct-injection or fan-shaped filling fuel nozzles 31, and the positions of the multiple filling fuel nozzles 31 match the positions of the multiple filling drain holes 18, so as to ensure that the filling fuel is discharged from the flame stabilizer 1.

[0049] The filling fuel is transversely injected from the direct-injection or fan-shaped nozzles 31 on the filling fuel injection rod 3, and the filling fuel is discharged from the flame stabilizer 1 through the filling drain holes 18. Since the transverse injection has the characteristics of large penetration depth and wide coverage, the filling fuel can be more fully and evenly distributed in the non-blocked area outside the flame stabilizer, thus ensuring that this integrated system has excellent combustion efficiency.

[0050] In summary, the cooling air enters the inside of the flame stabilizer 1 from the cooling air inlet pipe 12 and is divided into four parts. The first part of the cooling air reaches the middle and front area of the flame stabilizer through the first air flow passage a and leaves the flame stabilizer from the air film holes 19 and the filling drain holes 18 on both sides of the flame stabilizer. The cooling air leaving from the air film holes forms a cooling air film on the outer surface of the flame stabilizer to protect the flame stabilizer. The second part of the cooling air enters the inner shell 16 of the stabilizer through the first air flow passage a and the air holes at the trailing edge of the inner shell 16 of the stabilizer to prevent the high-temperature gas in the afterburner from flowing back under non-afterburning conditions, thus solving the problem of coking of the fuel injection rod. The third part of the cooling air reaches the leading edge of the flame stabilizer 1 through the first air flow passage a, the second air flow passage b and the front impact baffle 14 and leaves the flame stabilizer from the air film holes at the leading edge. The fourth part of the cooling air leaves the flame stabilizer from the air film holes at the trailing edge of the flame stabilizer 1 through the rear impact baffle 15; the above-mentioned third part and fourth part of the cooling air also form a cooling air film on the outer surface of the flame stabilizer. In addition, the front impact baffle 14 and the rear impact baffle 15 adopt the scheme of impingement cooling to further cool the leading edge and the trailing edge of the flame stabilizer.

[0051] In another aspect of the present invention, there is provided a variable cycle engine, characterized by comprising an oil-gas separation integrated flame stabilizer system according to any one of claims 1-8.

[0052] Preferably, the flame stabilizer 1 is disposed inside the trailing edge of the splitter ring or outside the center cone of the afterburner of the variable cycle engine, and the cooling air inlet pipe 12 is configured to introduce cooling air from the outer bypass duct or the core fan.

Claims

1. An integrated oil-gas separation type flame stabilizer system, characterized in that, it includes: A flame stabilizer (1), which includes a stabilizer outer casing (11), a stabilizer inner casing (16) arranged inside the stabilizer outer casing (11), and a duty oil passage (17) that communicates the outside of the stabilizer outer casing (11) with the inside of the stabilizer inner casing (16); A duty injection rod (2), installed inside the stabilizer inner casing (16), and injecting duty fuel to the outside of the flame stabilizer (1) through the duty oil passage (17); A filling injection rod (3), installed inside the stabilizer outer casing (11) and located at the rear side of the stabilizer inner casing (16), and injecting filling fuel to the outside of the flame stabilizer (1) through a filling drain hole (18) provided on the side wall of the stabilizer outer casing (11); and A cooling air inlet pipe (12), capable of introducing cooling air into the inside of the stabilizer outer casing (11), wherein a first part of the cooling air passes through the filling injection rod (3) and discharges from the filling drain hole (18) out of the stabilizer outer casing (11), and a second part of the cooling air enters the inside of the stabilizer inner casing (16) through the air holes at the trailing edge of the stabilizer inner casing (16) to cool the duty injection rod (2).

2. The integrated oil-gas separation type flame stabilizer system according to claim 1, characterized in that, The flame stabilizer (1) further includes a solid partition (13), the stabilizer inner casing (16) is arranged in the front area inside the stabilizer outer casing (11), the cooling air inlet pipe (12) communicates with the rear area of the stabilizer outer casing (11), and the solid partition (13) is arranged in the middle area inside the stabilizer outer casing (11) and located at the rear side of the filling injection rod (3); wherein, one of the two side walls in the radial direction of the stabilizer outer casing (11) is spaced from the solid partition (13) to form a first air flow channel (a), and the other side wall is attached to the solid partition (13) and communicates with the cooling air inlet pipe (12).

3. The integrated oil-gas separation type flame stabilizer system according to claim 2, characterized in that, A plurality of the duty oil passages (17) are arranged at intervals in the radial direction of the stabilizer outer casing (11), so as to enclose a second air flow channel (b) between two adjacent duty oil passages (17), the stabilizer inner casing (16) and the stabilizer outer casing (11); wherein, the flame stabilizer (1) further includes a front impact partition (14) arranged at the front side of the stabilizer inner casing (16), the front impact partition (14) is provided with a plurality of impact air holes, and a third part of the cooling air passes through the first air flow channel (a), the second air flow channel (b) and the impact air holes on the front impact partition (14), and impacts the inside of the leading edge of the stabilizer outer casing (11) for cooling.

4. The integrated oil-gas separation type flame stabilizer system according to claim 3, characterized in that, The flame stabilizer (1) further includes a rear impact partition plate (15) disposed at the rear side of the cooling air inlet pipe (12). A plurality of impact air holes are provided on the rear impact partition plate (15). The cooling air in the fourth part impacts the inner side of the trailing edge of the stabilizer outer casing (11) through the impact air holes on the rear impact partition plate (15) for cooling.

5. The oil-gas separation integrated flame stabilizer system according to claim 4, wherein, gas film holes (19) are respectively provided at the leading edge and the trailing edge of the stabilizer outer casing (11), so that the cooling air in the third part and the fourth part respectively passes through the gas film holes (19) to form gas film cooling at the leading edge and the trailing edge of the stabilizer outer casing (11); and, gas film holes (19) are provided at the position of the side wall of the stabilizer outer casing (11) close to the filling and oil draining holes (18) to at least partially divert the cooling air in the first part to form gas film cooling on the side wall of the stabilizer outer casing (11).

6. The oil-gas separation integrated flame stabilizer system according to claim 1, wherein, the pilot injection rod (2) is provided with a plurality of direct injection nozzles (21) configured to inject fuel from the rear to the front, so that the fuel impacts the leading edge of the stabilizer inner casing (16) and then is discharged from the flame stabilizer (1) through the stabilizer inner casing (16), the pilot oil passage (17) and the stabilizer outer casing (11).

7. The oil-gas separation integrated flame stabilizer system according to claim 6, wherein, the total passage area of the plurality of pilot oil passages (17) is larger than the total area of the plurality of direct injection nozzles (21).

8. The oil-gas separation integrated flame stabilizer system according to claim 1, wherein, the filling injection rod (3) is provided with a plurality of direct injection or fan-shaped filling fuel nozzles (31). The positions of the plurality of filling fuel nozzles (31) match the positions of the plurality of filling and oil draining holes (18), so as to ensure that the filling fuel is discharged from the flame stabilizer (1).

9. A variable cycle engine, wherein, it includes the oil-gas separation integrated flame stabilizer system according to any one of claims 1-8.

10. The variable cycle engine according to claim 9, wherein, the flame stabilizer (1) is disposed inside the trailing edge of the splitter ring or outside the center cone of the afterburner of the variable cycle engine, and the cooling air inlet pipe (12) is configured to introduce cooling air from the outer bypass duct or the core fan.

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