Wide-range composite dual-oil-path nozzle

Abstract

The application belongs to the field of aero gas turbine engine combustion chamber design, and particularly relates to a wide-range adjustable composite double-oil-path nozzle. The internal flow of the nozzle is mainly divided into four parts, including a center injection area, a head light blowing area, an outer ring injection area and an outer ring coaxial air area. The center injection area mainly works under low fuel supply pressure to ensure the oil mist distribution in the center of the combustion chamber. The center oil path adopts a centrifugal atomizer, and the fuel is distributed in a hollow cone shape in the center area. The head light blowing area has a small air area and is distributed in a circumferential rotation manner. The light blowing air is mainly used to blow off the carbon deposited on the nozzle head in the high-temperature environment of the combustion chamber. The outer ring area is distributed in a straight injection annular manner. The fuel is injected into the combustion chamber after being injected by high pressure. Since the center concentration of the straight injection nozzle is high and the fuel momentum is large, the fuel can reach the design injection point in the combustion area, thereby ensuring the atomization effect and fuel concentration distribution.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of aero gas turbine engine combustion chamber design, in particular to a wide adjustment range composite double oil path nozzle. BACKGROUND

[0002] The present application belongs to the field of aero gas turbine engine combustion chamber design, in particular to the field of combustion chamber fuel injection design.

[0003] Modern aero gas turbine engine combustion chamber fuel injection generally adopts a structure of double oil path centrifugal nozzle or composite air atomization nozzle matched with double swirl or multi-swirl atomization device design, with the increasing temperature rise potential demand of aero engine main combustion chamber, under high oil gas ratio working conditions, the commonly used double oil path centrifugal nozzle type cannot consider high fuel adjustment range, due to the increase of combustion chamber environmental pressure, the back pressure under design working condition can reach dozens of atmospheres, the atomization distribution downstream of the head is greatly affected under high back pressure environment, the atomization cone angle of such nozzle changes greatly under main combustion chamber design state working, the atomization quality deteriorates, and the atomization distribution range is compressed sharply. While the composite air atomization nozzle has a large space size, and the limitation of combustion chamber air distribution needs to be considered. In order to solve the problems of combustion efficiency, exhaust smoke, flameout performance and outlet temperature field deterioration of the combustion chamber under high oil gas ratio working condition, the design of fuel injection device is a main key factor.

[0004] The prior art double oil path nozzle includes two technical approaches, one is double oil path centrifugal nozzle, that is, the center stage and the outer ring adopt centrifugal nozzles, the center centrifugal nozzle mainly ensures combustion stability, the flow number is small, the nozzle cone angle is small, and the outer ring centrifugal nozzle has large flow number and wide spray cone angle. The other is a composite air atomization nozzle, the center adopts a centrifugal nozzle or a pre-mode air atomization, and the main combustion stage adopts a pre-mode or a jet type air atomization.

[0005] The prior art has the following problems:

[0006] 1. Although the double oil path centrifugal nozzle has a wide flow range, due to the limitation of the outer diameter structure of the centrifugal nozzle, the flow number of the outer ring centrifugal nozzle continues to increase;

[0007] 2. The double oil path centrifugal nozzle adopts swirl centrifugal atomization technology, and domestic and foreign research shows that under the high back pressure working environment of the combustion chamber, the atomization cone angle is greatly reduced, and the spray quality and injection position cannot be guaranteed.

[0008] When the composite air atomization nozzle adopts air atomization structure, the radial distance between the main combustion stage and the pre-combustion stage is far, the heat protection problem of the main combustion stage needs to be realized by engineering, and due to the need to design the position of the air swirler, the head diameter is large, and the head of the flame tube needs to be greatly improved when designing and modifying. SUMMARY

[0009] To solve the above problems, the application provides a wide adjustment range composite double oil path nozzle, comprising:

[0010] The straight jet nozzle group and the centrifugal atomizer assembly;

[0011] The straight jet nozzle group has an outer wall surface and an inner wall surface, and an outer annular surface passage is formed between the outer wall surface and the inner wall surface, and the outer annular surface passage is communicated with a plurality of light blowing air holes at the end surface of the straight jet nozzle group; the centrifugal atomizer assembly is inserted into the central hole formed by the inner wall surface, and the outer wall surface and the inner wall surface of the centrifugal atomizer assembly form an annular fuel area, the annular fuel area is connected with the first oil path, the inner wall surface extends to the outer wall surface direction to form a plurality of circumferentially distributed cylindrical nozzles, the cylindrical nozzles pass through the outer annular surface passage and the outer wall surface and form a passage for spraying fuel outward from the annular fuel area; the cylindrical nozzles and the outer wall surface have an annular air gap for air flow;

[0012] The end of the centrifugal atomizer assembly is fixedly connected with the inner wall surface, the centrifugal atomizer assembly has a central passage, the central passage is connected with the second oil path, and the central passage sprays fuel out through the central hole at the end surface of the straight jet nozzle group.

[0013] Preferably, the centrifugal atomizer assembly comprises an adapter oil pipe, a nozzle sleeve connected with the adapter oil pipe, and a swirler in the nozzle.

[0014] Preferably, the end surface of the adapter oil pipe is sleeved in the nozzle, the front end of the nozzle gradually narrows to form a conical surface, and the end surface of the adapter oil pipe abuts against the swirler inside the nozzle.

[0015] Preferably, the outer wall surface and the inner wall surface of the straight jet nozzle group form a conical surface at the front end, and the outer annular surface passage forms a conical annular cavity at the conical surface.

[0016] Preferably, the composite double oil path nozzle is connected with a shell, the shell has a central second oil path and an annular first oil path formed by the wall surface of the second oil path and the shell shell; the wall surface of the second oil path is connected with the adapter oil pipe through an oil pipe; and the end surface of the inner wall surface is connected with the shell shell.

[0017] Preferably, a plurality of support ribs are arranged between the outer wall surface and the inner wall surface, the support ribs have a fan-shaped cross section, are circumferentially distributed along the outer annular surface passage, the length of the support rib plate is less than the length of the straight section of the outer annular surface passage, and the support rib plate is located upstream of the cylindrical nozzle.

[0018] Preferably, the radial height of the cylindrical nozzle is higher than the outer surface of the outer wall surface.

[0019] Preferably, the number of support rib plates is 1-2 times the number of cylindrical nozzles, and the fan-shaped cross section of the support rib plate is concentrically arranged with the outer wall surface of the nozzle.

[0020] Preferably, the number of air blowing holes is 12-20, and the airflow rotation angle is 25-40 degrees.

[0021] Preferably, the front end of the nozzle is gradually expanded in a trumpet shape.

[0022] The advantages of the present application include: 1. The technology can be applied to the head structure of a multi-stage cyclone device. Since the flow number of the direct jet sprayer is small and can be controlled according to the number and aperture, the adjustment range is large. When the combustion chamber works in a high oil-gas ratio state, the fuel flow ratio between the outer stage and the center stage can be very high.

[0023] 2. In a high back pressure working environment of the combustion chamber, the fuel injection structure and method described in the patent have little influence on the quality and injection position of the outer ring spray, which is affected by environmental pressure and other parameters.

[0024] 3. When matched with a multi-stage cyclone atomization device, it can achieve good atomization quality and distribution in various flow states, small radial size, and compact overall structure. The adjacent design of the center stage and the outer ring fuel passage can provide thermal protection for the outer ring passage. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a cross-sectional view of a preferred embodiment of a composite direct injection double oil path nozzle head structure of the present application;

[0026] Figure 2 is a side view of a direct jet nozzle group of a preferred embodiment of the present application;

[0027] Figure 3 is a cross-sectional view of a direct jet nozzle group of a preferred embodiment of the present application;

[0028] Figure 4 is a side view of a direct jet nozzle group of a preferred embodiment of the present application;

[0029] Figure 5 is a side view of a direct jet nozzle group of a preferred embodiment of the present application;

[0030] Figure 6 is a side view of a direct jet nozzle group of a preferred embodiment of the present application; DETAILED DESCRIPTION

[0031] For the purpose of the present application, the technical solutions and advantages will be clearer, the following will be combined with the drawings in the embodiments of the present application, the technical solutions in the embodiments of the present application will be described in more detail. In the drawings, the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The described embodiments are part of the embodiments of the present application, rather than all the embodiments. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application. The embodiments of the present application are described in detail below in combination with the drawings.

[0032] A wide adjustment range of composite direct injection structure of double oil path nozzle, including direct injection nozzle group 1, centrifugal sprayer assembly, shell 3, oil pipe 4, adapter pipe 5, coaxial air ring 30, support rib plate, cold blow hole plate 40, annular air gap 50.

[0033] The specific structure is a double oil path injection device, the injection end is a concentric annular device, the direct injection nozzle group 1 is located at the outer ring position of the nozzle, and is connected with the shell 3 through welding or screw thread connection, and is connected with the inner ring centrifugal sprayer assembly through axial end face cooperation connection, the direct injection nozzle head is provided with a constricted circular hole channel, the centrifugal sprayer assembly is arranged inside the channel, the centrifugal sprayer assembly includes an adapter pipe 5, a cyclone 2 and a nozzle 6, the cyclone is arranged on the inner surface of the nozzle 6 and is connected through end face sealing, the front end face of the adapter pipe 5 is tightly connected with the cyclone 2, an oil inlet channel is arranged in the adapter pipe 5, the outer surface of the adapter pipe 5 is connected with the nozzle 6 through welding, the other end of the adapter pipe 5 is connected with the oil pipe stop and is welded, and the oil pipe 4 is connected with the nozzle shell inner channel ring positioning. The outer ring surface of the centrifugal sprayer nozzle 6 forms a second fuel passage with the inner ring of the direct injection nozzle group 1, and the front end of the direct injection nozzle group 1 is positioned and welded with the outer channel ring of the nozzle shell.

[0034] The double oil path device is a cylindrical annular channel, the channel includes two fuel inlets and an external air ring gap. Fuel medium enters the inner ring channel of the nozzle head through the oil inlet of the nozzle shell, the center channel 10 fuel enters the centrifugal atomizer in the center, flows out through the center large hole of the direct injection nozzle end face, and the annular fuel area 20 is sprayed out through the cylindrical direct injection nozzle on the conical end face of the direct injection nozzle group; an air inlet gap is arranged at the axial front end of the direct injection nozzle group 1, external air enters the outer ring channel 30 of the direct injection nozzle group through the air inlet gap, a plurality of support rib plates are arranged inside the front section of the direct injection inner ring and outer ring, the cross section of the support rib plate is fan-shaped, the circumferential direction is connected with the end faces of the inner ring and the outer ring, and the length of the support rib plate is less than the length of the straight section of the inner cavity. The downstream of the support rib plate is provided with a plurality of cylindrical nozzles.

[0035] The main structural features of the direct injection nozzle group 1 are that the outer surface of the channel has an annular conical surface, the conical surface has a plurality of circular air outlet holes, the front end surface is a radial plane, and the end surface has a plurality of light blowing air holes 40; the inlet of the inner ring outer surface is a round corner contraction section, followed by a flat section, the flat section is connected with the inner surface of the outer ring through a support rib plate, the rear section of the inner ring is a contraction channel, a plurality of integrated cylindrical nozzles are arranged on the contraction channel, the cylindrical nozzles are perpendicular to the surface of the contraction channel, the cylindrical nozzles are coaxial with the air outlet holes of the outer ring and form an annular air gap 50, the cylindrical nozzles should be higher than the outer annular conical surface by 0.3-0.8 mm. The outer surface of the inlet is connected in the direction of the gas flow, the gas flow flows along the space between the support rib plates after entering the outer ring channel, and then flows out along the air gap 50 on the outer ring surface conical surface, and another part of the air flows out along the plurality of small holes 40 on the end surface; the fuel of the nozzle group outer ring enters the inner hole of the cylindrical nozzle from the inner ring of the direct injection nozzle group 1, and is sprayed out at high speed.

[0036] The main flow path of the centrifugal spray device is that the fuel of the nozzle group outer ring enters the spray atomizer swirler from the fuel pipeline, and is sprayed out at high speed through the internal high-speed rotation of the nozzle.

[0037] The number of cylindrical nozzles of the direct injection nozzle group is 6-12, and the included angle between the cylindrical body and the end surface is 80-100;

[0038] The number of support rib plates in the direct injection nozzle group is 1-2 times the number of cylindrical nozzles, and the fan-shaped part is concentrically arranged with the nozzle outer ring;

[0039] The number of light blowing air holes (40) of the nozzle head is 12-20, and the gas flow rotation angle is 25-40;

[0040] The double-oil-path composite nozzle described in the present application is mainly used for the injection device of the high-swirl atomizing device of the main combustion chamber of an aero-engine. Generally, the combustion chamber head thereof has a plurality of swirler stages, most of the air entering the combustion chamber enters from the head swirler device, and the nozzle mainly realizes the fuel supply characteristics in a wide working range and ensures the distribution and position of the sprayed fuel under high temperature and high pressure working conditions. The nozzle adopts a concentrically distributed centrifugal and direct injection mixed double-oil-path nozzle structure, and the main working modes are as follows: the central stage mainly works under low state, the central stage and the direct injection stage work together under high working state of the engine, and the flow ratio of the direct injection stage to the central stage can reach about 8-13 under high state.

[0041] The main flow inside the nozzle is divided into four parts, including the center injection area, the head light blowing area, the outer ring injection area and the outer ring coaxial air area. The center injection area mainly works at low fuel supply pressure to ensure the oil mist distribution in the center of the combustion chamber. The centrifugal atomizer is used in the center oil way, and the fuel is distributed in a hollow cone in the center area. The head light blowing area has a small air area and is distributed in the circumferential direction. The light blowing air is mainly used to blow off the carbon deposit in the high temperature environment of the combustion chamber. The outer ring area is distributed in a straight injection ring. The fuel is injected into the combustion chamber after being pressurized. Since the center concentration of the straight injection nozzle is high and the fuel momentum is large, the fuel can reach the design injection point in the combustion area, ensuring the atomization effect and fuel concentration distribution. The outer ring air area is coaxial with the straight injection rod body. The air flows out from the interlayer of the support rib plate through the axial slot on the nozzle head. The outer ring air mainly cools the outer ring oil hole during work, blows off the deposited fuel at the straight injection port position, and prevents the nozzle surface from carbon depositing.

[0042] The above merely provides a specific implementation of the present application, but the protection scope of the present application is not limited to this. Any changes or replacements that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A wide adjustment range compound dual oil passage nozzle characterized by, include: Direct-fire nozzle assembly (1) and centrifugal sprayer assembly; The direct-fire nozzle assembly (1) has an outer wall surface and an inner wall surface. An outer annular channel (30) with an opening on the outer surface is formed between the outer wall surface and the inner wall surface. The outer annular channel (30) is connected to a plurality of light-blowing air holes (40) at the end face of the direct-fire nozzle assembly (1). The centrifugal sprayer assembly is inserted into the central hole formed by the inner wall surface. The outer wall surface and the inner wall surface of the centrifugal sprayer assembly form an annular fuel zone (20). The annular fuel zone (20) is connected to the first oil passage. The inner wall surface extends towards the outer wall surface to form a plurality of circumferentially distributed cylindrical nozzles. The cylindrical nozzles pass through the outer annular channel (30) and the outer wall surface and form a channel that connects the annular fuel zone (20) to spray fuel outward. There is an annular air gap (50) between the cylindrical nozzles and the outer wall surface to allow air to circulate. The centrifugal sprayer assembly is fixedly connected to the inner wall surface at its end. The centrifugal sprayer assembly has a central channel (10) which is connected to the second oil circuit. The central channel (10) sprays fuel through the central hole at the end face of the direct-fire nozzle assembly (1).

2. The wide adjustment range compound dual oil passage nozzle according to claim 1, wherein The centrifugal sprayer assembly includes a transfer oil pipe (5), a nozzle (6) connected to the transfer oil pipe (5), and a cyclone separator (2) inside the nozzle (6).

3. The wide adjustment range compound dual oil passage nozzle according to claim 2, wherein The end face of the transfer oil pipe (5) is fitted inside the nozzle (6), and the front end of the nozzle (6) gradually shrinks to form a conical surface. The end face of the transfer oil pipe (5) presses the cyclone separator (2) against the inside of the nozzle (6).

4. The wide adjustment range compound dual oil passage nozzle according to claim 1, wherein The outer and inner walls of the direct-fire nozzle assembly (1) form a conical surface at the front end, and the outer annular channel (30) forms a conical annular cavity at the conical surface.

5. The wide adjustment range compound dual oil passage nozzle according to claim 1, wherein The composite dual-oil-path nozzle is connected to the housing (3). The housing (3) has a central second oil path and an annular first oil path formed by the wall of the second oil path and the outer shell of the housing (3). The wall of the second oil path is connected to the transfer oil path (5) through the oil pipe (4). The outer shell of the housing (3) is connected to the end face of the inner wall.

6. The composite dual-oil-path nozzle with a wide adjustment range as described in claim 1, characterized in that, Multiple support ribs are provided between the outer wall and the inner wall. The cross-section of the support ribs is fan-shaped and distributed circumferentially along the outer ring channel (30). The length of the support ribs is less than the length of the straight section of the outer ring channel (30). The support ribs are located upstream of the cylindrical nozzle.

7. The composite dual-oil-path nozzle with a wide adjustment range as described in claim 1, characterized in that, The radial height of the cylindrical nozzle is higher than the outer surface of the outer wall.

8. The composite dual-oil-path nozzle with a wide adjustment range as described in claim 6, characterized in that, The number of support ribs is 1 to 2 times the number of cylindrical nozzles, and the fan-shaped cross-section of the support ribs is arranged concentrically with the outer wall of the nozzle.

9. The composite dual-oil-path nozzle with a wide adjustment range as described in claim 1, characterized in that, The number of air holes (40) is 12 to 20, and the airflow rotation angle is between 25 and 40 degrees.

10. The composite dual-path nozzle with a wide adjustment range as described in claim 1, characterized in that, The front end of the nozzle (6) is a gradually expanding trumpet shape.

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