CN117869935A

CN117869935A - Backflow combustion device

Info

Publication number: CN117869935A
Application number: CN202410014523.5A
Authority: CN
Inventors: 康尧; 张荣幸; 戴金鑫; 江立军; 郎旭东
Original assignee: Hunan Aviation Powerplant Research Institute AECC
Current assignee: Hunan Aviation Powerplant Research Institute AECC
Priority date: 2024-01-03
Filing date: 2024-01-03
Publication date: 2024-04-12

Abstract

The application discloses backward flow burner, the device includes: a housing; the vortex device is arranged on the shell; the air atomizing nozzle is mounted on the swirler. The device adopts the design of a direct injection nozzle, an inner cyclone, an atomization venturi tube and a nozzle shell, has wide range of fuel regulation ratio, is insensitive to fuel pollution and can adapt to various liquid fuels; the pressure requirement on the fuel system is low, the fuel and air are uniformly mixed, the spatial distribution of oil mist is wide, the atomization effect is good in a wide working range, and the exhaust smoke in a high-power state can be effectively reduced; the direct injection nozzle has simple fuel flow passage, high-speed airflow is wrapped around the fuel flow passage, and coking and carbon deposition are not easy to occur.

Description

Backflow combustion device

Technical Field

The application relates to the technical field of aero-engines, and relates to a backflow combustion device.

Background

The current aeroengine backflow combustion chamber mainly adopts a single-oil-way or double-oil-way centrifugal nozzle to atomize fuel, the centrifugal nozzle has a complex structure, has very high requirements on processing precision and high price, and has the advantages of low fuel regulation ratio, high fuel pressure, centralized oil mist distribution, large influence of fuel pollution and easy coking and carbon deposition. The air atomizing nozzle has the advantages of simple structure, low processing requirement, low price, low requirement on fuel pressure and insensitivity to fuel pollution, but poor atomizing quality under low working conditions and adverse on the on-off performance of the combustion chamber.

The single-oil-way or double-oil-way centrifugal nozzle can have good atomization performance under low working conditions such as starting, slow running and the like, such as the single-oil-way or double-oil-way centrifugal nozzle adopted by a return combustion chamber of a PT6 series engine. In addition, centrifugal nozzles have also found a number of applications in dc combustors, such as CFM56 series engines and F110 engines. However, the centrifugal nozzle has the problems of small fuel regulation ratio, high fuel pressure requirement, complex structure, difficult processing, easy exhaust and smoke emission, and the like. The backflow combustion chamber is generally suitable for medium and small aeroengines, the fuel flow is small, the influence of cost is large, and the problems of difficult processing and high price are caused by adopting a complex centrifugal nozzle; and because the size of the backflow combustion chamber of the medium and small aero-engine is generally smaller, a very complex pneumatic atomizing nozzle cannot be adopted.

Disclosure of Invention

The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview, and is intended to neither identify key/critical elements nor delineate the scope of such embodiments, but is intended as a prelude to the more detailed description that follows.

Embodiments of the present disclosure provide a reflow combustion apparatus, the apparatus comprising:

a housing;

a swirler mounted on the housing;

an air atomizing nozzle mounted on the swirler.

Further, the swirler includes:

the primary swirler is provided with a fuel nozzle mounting hole for mounting the air atomizing nozzle;

a venturi mounted on the primary swirler;

a secondary swirler mounted on the venturi.

Further, a plurality of vortex grooves are formed in the primary vortex device; the secondary swirler is provided with a plurality of swirl channels.

Further, the air atomizing nozzle includes:

the nozzle shell is provided with an inner cyclone air inlet and an outer cyclone air inlet;

an atomization venturi tube welded on the inner wall of the nozzle shell;

an inner cyclone welded on the inner wall of the atomization venturi tube and provided with a plurality of vortex grooves;

the direct injection nozzle is inserted into the pore canal of the inner cyclone.

Further, the direct injection nozzle is provided with a plurality of round holes with the diameter of 0.2mm-0.4 mm.

Further, the aperture range of the inner rotator air inlet hole is 3mm-6mm, and the number range is 1-3.

Further, the aperture range of the external swirl air inlet hole is 1mm-3mm, and the number range is 6-12.

Further, the outer diameter of the direct injection nozzle is D1, the throat diameter of the atomizing venturi is D2, and D2 is 1.5-3 times of D1.

Further, the distance between the end face of the direct injection nozzle and the throat of the atomizing venturi is L1, and the value range of L1 is 0.5mm-2mm.

Further, the angle of the section line of the convergence section of the atomizing venturi is alpha, the value range of alpha is 40-80 degrees, the angle of the section line of the expansion section of the atomizing venturi is beta, and the value range of beta is 20-40 degrees.

Further, the tangential angle of the outer swirling air inlet hole is an included angle gamma between the central line and the horizontal, and the included angle gamma ranges from 20 degrees to 50 degrees.

The embodiment of the disclosure provides a reflux combustion device, which can realize the following technical effects:

(1) The direct injection nozzle, the inner cyclone, the atomization venturi tube and the nozzle shell are adopted, the range of the fuel oil regulation ratio is wide, the fuel oil pollution is insensitive, and the device can be suitable for various liquid fuels;

(2) The pressure requirement on the fuel system is low, the fuel and air are uniformly mixed, the spatial distribution of oil mist is wide, the atomization effect is good in a wide working range, and the exhaust smoke in a high-power state can be effectively reduced;

(3) The direct injection nozzle has simple fuel flow passage, and the periphery is wrapped with high-speed air flow, so that coking and carbon deposition are not easy to occur;

(4) The air atomizing nozzle has the advantages of simple structure, convenient processing and low cost.

Drawings

One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which like reference numerals refer to similar elements, and in which:

FIG. 1 is a cross-sectional view of a reverse flow combustion device provided by an embodiment of the present disclosure;

FIG. 2 is a cross-sectional view of a swirler and an air atomizing nozzle provided by an embodiment of the present disclosure;

FIG. 3 is a cross-sectional view of a swirler provided by an embodiment of the present disclosure;

FIG. 4 is a cross-sectional view of an air atomizing nozzle provided by an embodiment of the present disclosure;

FIG. 5 is a cross-sectional view of an outer swirl air intake aperture provided by an embodiment of the present disclosure;

fig. 6 is a schematic structural view of an inner cyclone provided in an embodiment of the present disclosure.

In the figure: 1. the burner comprises a diffuser, 2, a combustion chamber outer casing, 3, a combustion chamber inner casing, 4, a flame tube outer ring, 5, a flame tube inner ring, 6, a flame tube head ring, 7, a vortex device, 8, an air atomizing nozzle, 9, a large bent pipe, 10, a small bent pipe, 11, a guide plate, 12, a fuel nozzle mounting hole, 13, a primary vortex device, 14, a venturi, 15, a secondary vortex device, 16, a direct injection nozzle, 17, an inner cyclone device, 18, an atomizing venturi, 19, a nozzle housing, 20, an inner cyclone air inlet hole, 21, an outer cyclone air inlet hole, 22 and a cyclone groove.

Detailed Description

So that the manner in which the features and techniques of the disclosed embodiments can be understood in more detail, a more particular description of the embodiments of the disclosure, briefly summarized below, may be had by reference to the appended drawings, which are not intended to be limiting of the embodiments of the disclosure. In the following description of the technology, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the disclosed embodiments. However, one or more embodiments may still be practiced without these details. In other instances, well-known structures and devices may be shown simplified in order to simplify the drawing.

Referring to fig. 1-6, embodiments of the present disclosure provide a reflow combustion apparatus including:

a housing;

a swirler 7 mounted on the housing;

an air atomizing nozzle 8 is mounted on the swirler 7.

In some embodiments of the invention, the swirler 7 comprises:

a primary swirler 13 provided with a fuel nozzle mounting hole 12 for mounting the air atomizing nozzle 8;

a venturi 14 mounted on the primary swirler 13;

a secondary swirler 15 mounted on said venturi 14.

In some embodiments of the present invention, the primary swirler 13 is provided with a plurality of swirl channels; the secondary swirler 15 is provided with a plurality of swirl channels.

In some embodiments of the invention, the air atomizing nozzle 8 comprises:

a nozzle housing 19 on which an inner cyclone air intake 20 and an outer cyclone air intake 21 are mounted;

an atomizing venturi 18 welded to the inner wall of the nozzle housing 19;

an inner cyclone 17 welded on the inner wall of the atomization venturi 18 and provided with a plurality of vortex grooves 22;

the direct injection nozzle 16 is inserted in the pore canal of the inner rotator 17.

In some embodiments of the present invention, the direct injection nozzle 16 is provided with a plurality of circular holes having diameters of 0.2mm to 0.4 mm.

In some embodiments of the present invention, the inner swirler inlet 20 has a diameter ranging from 3mm to 6mm and a number ranging from 1 to 3.

In some embodiments of the present invention, the aperture of the outer swirling air intake holes 21 ranges from 1mm to 3mm, and the number ranges from 6 to 12.

In some embodiments of the present invention, the direct injection nozzle 16 has an outer diameter D1, the throat of the atomizing venturi 18 has a diameter D2, and D2 is 1.5-3 times D1.

In some embodiments of the present invention, the end face of the direct injection nozzle 16 is spaced from the throat of the atomizing venturi 18 by a distance L1, L1 ranging from 0.5mm to 2mm.

In some embodiments of the present invention, the converging section line angle of the atomizing venturi 18 is in the range of 40 ° -80 °, α is in the range of 20 ° -40 °, and the diverging section line angle of the atomizing venturi 18 is β.

In some embodiments of the present invention, the tangential angle of the outer swirl air intake holes 21 is the angle γ between the centerline and the horizontal, and the angle γ ranges from 20 ° to 50 °.

The invention adopts the direct injection nozzle to match the simple air atomizing nozzle with the double-stage rotary air flow venturi structure, has simple structure, convenient processing, low cost, is insensitive to the fuel pressure and can have good atomizing effect in a wide working range. The air atomizing nozzle has the advantages of uniform oil-gas mixing, insensitivity to liquid fuel types, wide fuel regulation ratio, simple structure, convenient processing and low cost.

A simple air atomizing nozzle and a backflow combustion chamber mainly comprise a diffuser, a combustion chamber casing, an air atomizing nozzle, an inner ring and an outer ring of a flame tube and the like, and the structure is shown in figure 1.

Fig. 1 shows a cross-sectional view of a combustion chamber, wherein the combustion chamber adopts a single-ring cavity structure, and a combustion chamber outer casing 2 and a combustion chamber inner casing 3 form a combustion chamber outer profile and are connected with a front compressor and a rear compressor and a turbine. The incoming air of the compressor enters the combustion chamber after being subjected to speed reduction diffusion from the diffuser 1, and the combustion is completed in the space surrounded by the flame tube outer ring 4, the flame tube inner ring 5, the flame tube head ring 6, the large bent pipe 9, the small bent pipe 10 and the guide plate 11 and the fuel atomized by the air atomizing nozzle 8 and the swirler 7.

Fig. 2 shows a cross-sectional view of the combination of the swirler and the air atomizing nozzle, and fig. 3 shows a cross-sectional view of the swirler. The air atomizing nozzle 8 is inserted into the primary swirler 13 through the fuel nozzle mounting hole 12. The swirler 7 is composed of a primary swirler 13, a venturi tube 14 and a secondary swirler 15, wherein a plurality of swirl channels (positioned between the fuel nozzle mounting hole 12 and the venturi tube 14) are formed on the primary swirler 13 for forming a swirl flow, a plurality of swirl channels (positioned behind the venturi tube 14) are formed on the secondary swirler 15 for forming a swirl flow, and a fuel nozzle mounting hole 12 is designed on the primary swirler 13 for mounting the air atomizing nozzle 8.

Fig. 4 is a sectional view of the air atomizing nozzle, fig. 5 is a sectional view of the outer swirl air intake hole, and fig. 6 is a three-dimensional view of the inner swirler 17 of the air atomizing nozzle 8. The air atomizing nozzle 8 is composed of a straight nozzle 16, an internal rotator 17, an atomizing venturi 18, and a nozzle housing 19. Round holes with the diameter of (0.2-0.4) mm are processed on the direct injection nozzle 16, swirl grooves 22 are designed on the inner swirler 17, the number of the swirl grooves is 6-12, an inner swirler air inlet hole 20 and an outer swirler air inlet hole 21 are designed on the nozzle shell, the aperture of the inner swirler air inlet hole 20 is (3-6) mm, and the number of the inner swirler air inlet holes is (1-3); the aperture of the outer cyclone air inlet holes 21 is (1-3) mm, the number is (6-12), and the design achieves the advantages that the open area of the inner cyclone air inlet holes is large, and enough airflow is ensured to enter the inner cyclone. The number of the external swirl air inlet holes is large, the aperture is small, and the uniformity of swirl air is improved. The direct injection nozzle 16 passes through the inner swirler 17 and is fixed to the inner swirler 17 by welding, the inner swirler 17 is fixed to the atomizing venturi 18 by welding, and the atomizing venturi 18 is fixed to the nozzle housing 19. The external diameter of the direct injection nozzle 16 is D1, the throat diameter of the atomizing venturi 18 is D2, D2 is equal to (1.5-3) times D1, the value is that on one hand, internal rotation air can smoothly circulate in the atomizing venturi, on the other hand, sufficient airflow velocity is guaranteed in the atomizing venturi, sufficient air kinetic energy is provided for atomizing fuel, the distance between the end face of the direct injection nozzle 16 and the throat of the atomizing venturi 18 is L1, the value of L1 is (0.5-2) mm, the value is that the fuel can be well atomized before the atomizing venturi, the angle of the cross section line of the convergent section of the atomizing venturi 18 is alpha, the value of alpha is (40-80) ° (the value is that airflow acceleration is guaranteed under the condition of small flow loss), the kinetic energy of the atomizing air is improved, on the one hand, the angle of the expansion section line of the atomizing venturi 18 is beta, the value of beta is that the cone angle of the atomizing air is increased, the radial distribution uniformity of the fuel is improved, on the other hand, the angle of the air flow is well separated due to rapid airflow flow, the angle of the swirl flow is the air flow is the proper value of the outside the air flow is the angle of the air flow, and the angle is the angle between the swirl angle of the swirl flow and the swirl flow is 20-80) (the value is the air flow is the proper value of the outside of the air flow).

When the combustion chamber works, the direct injection nozzle 16 ejects fuel, a part of high-pressure air from the diffuser 1 enters an annular channel formed by the direct injection nozzle 16 and the nozzle shell 19 through the inner rotator air inlet hole 20, and forms inner rotator air through the inner rotator 17, and accelerates air flow through the atomization venturi 18, so that initial atomization is formed on the fuel. A portion of the high pressure air from the diffuser 1 passes through the outer swirl air inlet 21 in the nozzle housing 19 to form outer swirl air which interacts with the inner swirl air at the outlet of the atomizing venturi 18 to secondarily atomize the fuel. The oil-gas mixture atomized by the air atomizing nozzle 8 is atomized again by the swirler and enters the flame tube for combustion reaction.

Through the device, the following steps are achieved: the direct injection nozzle, the inner cyclone, the atomization venturi tube and the nozzle shell are adopted, the range of the fuel oil regulation ratio is wide, the fuel oil pollution is insensitive, and the device can be suitable for various liquid fuels; the pressure requirement on the fuel system is low, the fuel and air are uniformly mixed, the spatial distribution of oil mist is wide, the atomization effect is good in a wide working range, and the exhaust smoke in a high-power state can be effectively reduced; the direct injection nozzle has simple fuel flow passage, and the periphery is wrapped with high-speed air flow, so that coking and carbon deposition are not easy to occur; the air atomizing nozzle has the advantages of simple structure, convenient processing and low cost.

The above description and the drawings illustrate embodiments of the disclosure sufficiently to enable those skilled in the art to practice them. Other embodiments may include structural and other modifications. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in, or substituted for, those of others. The embodiments of the present disclosure are not limited to the structures that have been described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A reflow burning apparatus, comprising:

a housing;

a swirler (7) mounted on the housing;

an air atomizing nozzle (8) mounted on the swirler (7); the swirler (7) comprises:

a primary swirler (13) provided with a fuel nozzle mounting hole (12) for mounting the air atomizing nozzle (8);

a venturi (14) mounted on said primary swirler (13);

a secondary swirler (15) mounted on the venturi (14).

2. A return flow combustion device according to claim 1, characterized in that the primary swirler (13) is provided with a plurality of swirl channels; the secondary swirler (15) is provided with a plurality of swirl channels.

3. A return flow combustion device according to claim 1, characterized in that the air atomizing nozzle (8) comprises:

a nozzle housing (19) on which an inner cyclone air inlet (20) and an outer cyclone air inlet (21) are mounted;

an atomization venturi (18) welded to the inner wall of the nozzle housing (19);

an inner cyclone (17) welded on the inner wall of the atomization venturi (18), and provided with a plurality of vortex grooves (22);

and the direct injection nozzle (16) is inserted into the pore canal of the inner cyclone (17).

4. A return firing device according to claim 3, characterized in that said direct injection nozzle (16) is provided with a plurality of circular holes having a diameter of 0.2mm-0.4 mm.

5. A return firing device according to claim 3, characterized in that the inner swirler inlet holes (20) have a hole diameter in the range of 3mm-6mm and a number in the range of 1-3.

6. A reflow burning apparatus in accordance with claim 3, wherein the aperture of the outer swirl air intake holes (21) is in the range 1mm-3mm, and the number is in the range 6-12.

7. A return firing device according to claim 3, characterized in that the direct injection nozzle (16) has an outer diameter D1, the throat diameter of the atomizing venturi (18) being D2, D2 being 1.5-3 times D1.

8. A return firing device according to claim 3, characterized in that the end face of the direct injection nozzle (16) is at a distance L1 from the throat of the atomizing venturi (18), L1 being in the range 0.5mm-2mm.

9. A return flow combustion device according to claim 8, wherein the converging section of the atomizing venturi (18) has a section line angle α in the range of 40 ° to 80 °, and the diverging section of the atomizing venturi (18) has a section line angle β in the range of 20 ° to 40 °.

10. A return air burner according to claim 3, wherein the tangential angle of the outer swirl air inlet holes (21) is in the range of 20 ° -50 ° from the centre line to the horizontal.