A new type of multi-ring fuel support plate injector

Abstract

The present invention discloses a novel multi-ring fuel support plate injector, which comprises: at least two layers of annular support plates, which are coaxially arranged in the combustion chamber of a rocket engine, and the diameter of each annular support plate decreases along the air flow direction of the combustion chamber; each annular support plate has: an annular fuel channel, which is arranged inside the annular support plate; two circles of injection hole arrays, which are arranged on both sides of the annular support plate in an inner and outer circle, each circle of injection hole array contains a plurality of injection holes arranged evenly, and each injection hole is connected to the annular fuel channel; four equal straight support plates, each equal straight support plate is connected and arranged between each annular support plate, and a fuel supply channel is arranged inside each equal straight support plate along its direction. It solves the problems of uneven injection area and uncontrollable injection density of existing injectors.

Description

Technical Field

[0001] The invention belongs to the technical field of scramjet engines or combined power engines, and in particular relates to a novel multi-ring fuel support plate injector. Background Art

[0002] The rocket-based ramjet combined cycle (RBCC) engine is a new type of combined power form that combines a rocket engine and a ramjet engine. Therefore, the RBCC engine integrates the high thrust-to-weight ratio of a rocket engine and the high specific impulse of a ramjet engine, thereby enabling the aircraft to achieve a wide range of speed adjustment from zero-speed takeoff to high Mach number flight, greatly improving mission adaptability and having huge development potential in future near-Earth aerospace transportation.

[0003] RBCC engines are divided into four modes: ejection mode, subsonic ramjet mode, scramjet mode and rocket mode. In the first three modes, the ramjet engine needs to be ignited and combustion is organized in the engine combustion chamber. The fuel required for combustion is injected by multiple support plates installed in the ramjet engine. Most of the fuel support plates currently used are straight support plates. The support plates are evenly arranged in front of the engine combustion chamber, and holes are punched on the side walls or back walls of the support plates to connect the oil supply pipeline to achieve fuel injection. However, when this type of support plate application method is used for injection in a large-sized circular combustion chamber, due to the limited penetration depth of the fuel injection, the fuel injection area will overlap in the center area of ​​the flow field and the fuel injection area will be empty in the near-wall area of ​​the flow field, which will affect the mixing efficiency of the fuel and the incoming flow and the combustion stability. In addition, the controllable injection of support plate fuel is also an important research topic in the combined power ramjet engine.

[0004] In RBCC engines, the design of the support plate has an important influence on the mixing of fuel and incoming flow and subsequent combustion. With the development of RBCC, the engine size will inevitably increase gradually, and in the large-scale circular flow field structure, the layout of the fuel support plate will further increase the influence on the injection uniformity and mixing efficiency. Summary of the invention

[0005] The purpose of the present invention is to provide a novel multi-ring fuel support plate injector to solve the problems of uneven injection area and uncontrollable injection density of the existing injectors.

[0006] The present invention adopts the following technical solution: a novel multi-ring fuel support plate injector, located in a combustion chamber, comprising:

[0007] At least two layers of annular support plates are coaxially arranged in a combustion chamber of a rocket engine at intervals, and the diameter of each annular support plate decreases along the air flow direction of the combustion chamber;

[0008] Each annular support plate has:

[0009] an annular fuel channel arranged inside the annular support plate;

[0010] Two circles of injection hole arrays, inner and outer, are arranged on both sides of the annular support plate, each circle of the injection hole array includes a plurality of injection holes arranged evenly, and each injection hole is connected to the annular fuel channel;

[0011] Four equal straight support plates, each of which is connected and arranged between the annular support plates, and a fuel supply channel is arranged inside each equal straight support plate along its direction;

[0012] Each fuel supply channel is connected to the annular fuel channel intersecting therewith, and each fuel supply channel is used to transport fuel to each annular fuel channel and inject fuel outward through each injection hole.

[0013] Furthermore, the annular fuel channel in each annular support plate is symmetrically divided into four sections of arc-shaped fuel channels that are not connected to each other, and the center of symmetry is the center of the circle of the annular support plate; the arc-shaped fuel channels on the same side of each layer of annular support plate are connected through an equal straight support plate to form an independent fuel channel unit.

[0014] Furthermore, in a fuel channel unit, the density of the injection holes in each circle of the injection hole array on each layer of the arc-shaped fuel channel gradually decreases in the direction from the center of the flow field to the outside.

[0015] Furthermore, each straight support plate is fixed to the inner wall surface of the combustion chamber, and one end of each straight support plate is connected to a fuel supply inlet.

[0016] The beneficial effects of the present invention are as follows: by performing double-sided injection on the annular support plate and setting up an arc-shaped fuel channel, the present invention can achieve full coverage of the injection of the flow field cross-sectional area and control of the fuel injection density gradient from the center area of ​​the flow field to the near-wall area of ​​the flow field by individually changing the fuel flow rate in the fuel supply channel of each straight support plate, or individually changing the flow area of ​​each section of the arc-shaped fuel channel, or individually changing the injection hole density in each circle of the injection hole array. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional structural schematic diagram of a novel multi-ring fuel support plate injector of the present invention;

[0018] Figure 2 It is a schematic diagram of an axial section of a novel multi-ring fuel support plate injector of the present invention along an equal straight support plate;

[0019] Figure 3 It is a structural schematic diagram of a novel multi-ring fuel support plate injector according to the present invention projected along the air flow direction;

[0020] Figure 4 yes Figure 3 The enlarged schematic diagram of the center C;

[0021] Figure 5 It is a partial schematic cross-sectional view of the connection between the annular support plate and the straight support plate of a novel multi-ring fuel support plate injector of the present invention.

[0022] Among them, 1. annular support plate; 2. straight support plate; 3. injection hole; 4. fuel supply inlet; 5. fuel supply channel; 6. annular fuel channel; 7. combustion chamber inner wall; 8. connecting flange. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] The present invention provides a novel multi-ring fuel support plate injector, such as Figure 1 As shown, located in the combustion chamber of the rocket engine, connecting flanges 8 are arranged at both ends of the combustion chamber, which include at least two layers of annular support plates 1 and four equal straight support plates 2.

[0025] The annular support plates 1 of each layer are coaxially arranged at intervals, and the diameter of the annular support plates 1 of each layer decreases along the air flow direction of the combustion chamber. Figure 3 As shown, each of the annular support plates 1 has the same structure, such as Figure 5 As shown, the annular support plate 1 includes an annular fuel channel 6 and two circles of injection hole arrays. An annular fuel channel 6 is arranged inside each layer of the annular support plate 1, and a circle of injection hole arrays are respectively arranged on the inner circle wall surface and the outer circle wall surface of each layer of the annular support plate 1, and each circle of the injection hole array includes a plurality of injection holes 3 arranged evenly, and each injection hole 3 is connected to the annular fuel channel 6.

[0026] The multiple annular support plates 1 used in the present invention all adopt double-sided fuel injection, so that the fuel can be spread into the incoming flow field at multiple angles, which not only reduces the fuel injection overlap in the center area of ​​the flow field, but also increases the fuel injection coverage range in the edge area of ​​the flow field, so that the circumferential uniformity of the fuel injection in the flow field is improved, and the total injection coverage of the incoming flow cross-sectional area is increased. For engines of different sizes, the number of annular fuel injection support plates 1 can be increased or decreased to ensure that the fuel injection coverage area and fuel injection uniformity are increased at the same time.

[0027] Multiple annular support plates 1 are arranged between each straight support plate, which improves the uniformity of injection and reduces the projected area of ​​the straight support plate in the incoming flow, thereby reducing the blocking ratio between the support plate and the incoming flow field and the total surface area of ​​the support plate in the flow field, thereby reducing the burden of structural thermal protection. In addition, the total mass of the support plate structure is reduced, which is conducive to reducing the dry weight of the engine.

[0028] like Figure 1and Figure 2 As shown, four straight support plates 2 are connected and arranged between the annular support plates 1, and a fuel supply channel 5 is arranged inside each straight support plate 2 along its direction, and each straight support plate 2 is evenly and spaced. Each fuel supply channel 5 is connected to the annular fuel channel 6 intersecting with it, and each fuel supply channel 5 is used to transport fuel to each annular fuel channel 6 and inject fuel outward through each injection hole 3. After the fuel is injected, it moves in the direction of the flow field airflow.

[0029] In some embodiments, Figure 3 As shown, the annular fuel channel 6 in each annular support plate 1 is symmetrically divided into four sections of arc-shaped fuel channels that are not connected to each other, and the symmetry center is the center of the circle of the annular support plate 1. The fuel flow in the four sections of the arc-shaped fuel channels can be controlled separately. The arc-shaped fuel channels on the same side of each layer of the annular support plate 1 are connected through an equal straight support plate 2 to form an independent fuel channel unit.

[0030] like Figure 3 As shown, a fuel channel unit includes an equal straight support plate 2 and a plurality of arc-shaped fuel channels connected to the equal straight support plates 2. Each annular support plate 1 is divided into four independent arc-shaped fuel channels, so that each injection area is separated, each section is controllable and adjustable, and the flow between the fuel inlets of two adjacent arc-shaped fuel channels is prevented from affecting each other. For example, the four independent arc-shaped fuel channels are respectively located at the upper left, lower left, upper right, and lower right positions of the annular support plate 1. The arc-shaped fuel channels in the same fuel channel unit are all located on the same side of the annular support plate 1. For example, the arc-shaped fuel channels located at the upper left position of each annular support plate 1 are connected through an equal straight support plate 2 to form a fuel channel unit.

[0031] In some embodiments, in a fuel channel unit, the density of the injection holes in each circle of the injection hole array on each layer of the arc-shaped fuel channel gradually decreases from the center of the flow field to the outside. Figure 3 As shown, taking the annular support plate 1 as two layers as an example, assuming that the density of the injection holes in the injection hole array on the inner and outer wall surfaces of the annular support plate 1 with a smaller diameter is ρ1 and ρ2 respectively, and the density of the injection holes in the injection hole array on the inner and outer wall surfaces of the annular support plate 1 with a larger diameter is ρ3 and ρ4 respectively, then along the direction from the center of the flow field to the outside, ρ1>ρ2>ρ3>ρ4. The density of the injection holes near the inner circle of the annular support plate 1 is higher than the density of the injection holes near the outer circle of the annular support plate 1. Such a setting can form a large amount of fuel injection in the central area and a small amount of injection near the inner wall surface 7 of the combustion chamber, so that the combustion reaction can be relatively concentrated in the central area of ​​the flow field, reducing the combustion near the inner wall surface 7 of the combustion chamber, and reducing the thermal protection pressure.

[0032] At the same time, in the four fuel channel units, the injection hole density of each arc-shaped fuel channel can be different, which is convenient for freely adjusting the injection density.

[0033] In some embodiments, each of the straight support plates 2 is fixed to the inner wall surface 7 of the combustion chamber, and one end of each of the straight support plates 2 is connected to a fuel supply inlet 4. The fuel supply inlet 4 is located on the outer wall of the combustion chamber.

[0034] like Figure 5 As shown, the cross-section of the connection between the annular fuel injection support plate 1 and the straight fuel supply support plate 2 is an integrally connected wedge and rectangle, the sharp corner of the wedge is rounded, the rounding radius is 1mm, and the fuel supply support plate is tilted backward at an angle of 30° along the flow field direction to reduce the resistance of the airflow in the flow field and reduce the thermal load on the leading edge of the support plate.

[0035] The method of using a novel multi-ring fuel support plate injector of the present invention is: the fuel is introduced into the fuel supply channel 5 in each straight support plate 2 through each fuel supply inlet 4, and then flows into each section of the annular fuel channel 6 of each annular support plate 1, and finally is ejected from the injection holes 3 of each circle of the injection hole array and burns in the combustion chamber.

[0036] The present invention performs double-sided injection on the annular support plate and sets up an arc-shaped fuel channel. It can achieve full coverage of the injection of the flow field cross-sectional area and control of the fuel injection density gradient from the center area of ​​the flow field to the near-wall area of ​​the flow field by individually changing the fuel flow rate in the fuel supply channel of each straight support plate, or individually changing the flow area of ​​each section of the arc-shaped fuel channel, or individually changing the injection hole density in each circle of the injection hole array.

Claims

1. A novel multi-ring fuel support plate injector, characterized in that: Located in the combustion chamber, it includes: At least two layers of annular support plates (1) are coaxially arranged in a combustion chamber of a rocket engine at intervals, and the diameter of each of the annular support plates (1) decreases along the air flow direction of the combustion chamber; Each of the annular support plates (1) has: an annular fuel channel (6) arranged inside the annular support plate (1); Two circles of injection hole arrays, the inner and outer circles being arranged on both sides of the annular support plate (1), each circle of the injection hole array comprising a plurality of injection holes (3) arranged evenly, each injection hole (3) being connected to the annular fuel channel (6); Four equal straight support plates (2), each of the equal straight support plates (2) being arranged in communication between the respective annular support plates (1), and a fuel supply channel (5) being arranged inside each of the equal straight support plates (2) along its direction; Each of the fuel supply channels (5) is connected to the annular fuel channel (6) intersecting therewith, and each of the fuel supply channels (5) is used to transport fuel to each of the annular fuel channels (6) and to inject fuel outward through each of the injection holes (3); The annular fuel channel (6) in each annular support plate (1) is symmetrically divided into four sections of arc-shaped fuel channels that are not connected to each other, and the center of symmetry is the center of the circle of the annular support plate (1); the arc-shaped fuel channels on each layer of the annular support plate (1) and located on the same side are connected through an equal straight support plate (2) to form an independent fuel channel unit; in a fuel channel unit, the density of the injection holes in each circle of the injection hole array on the arc-shaped fuel channels of each layer gradually decreases in the direction from the center of the flow field to the outside.

2. A novel multi-ring fuel support plate injector as claimed in claim 1, characterized in that: Each of the straight support plates (2) is fixed to the inner wall surface (7) of the combustion chamber, and one end of each of the straight support plates (2) is connected to a fuel supply inlet (4).

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