Exhaust cooling igniter outlet flame afterburning device

Abstract

The invention discloses a discharge cooling igniter outlet flame afterburning device, the upper end of the device is a cone with an injection hole, center high-temperature fuel gas ejected by a discharge cooling igniter is forcibly guided by the cone to flow to the periphery, and after being preliminarily mixed with cooling fuel on the outer layer, the center high-temperature fuel gas and the cooling fuel jointly flow downstream through the injection hole in the cone; the injection holes are symmetrically distributed, and mixed gas flowing out of the injection holes strikes and is mixed in the conical cavity, so that sufficient afterburning is realized; the reducing concave cavity is formed in the middle end of the device, mixed gas flows out of the conical cavity and then enters the reducing concave cavity, vortex is generated in the concave cavity, and the flow speed of the mixed gas is fully reduced; the lower end of the device is a flow outlet, and after being throttled, the gas flows out of the igniter. According to the afterburning device designed by the invention, high-temperature fuel gas and cooling fuel in the center of the igniter can be fully afterburnt, the energy of flame at the outlet of the igniter is improved, and the stability of the flame at the outlet of the igniter is enhanced, so that the reliability of igniting a rocket engine by the igniter is improved.

Description

Technical Field

[0001] The invention relates to the field of rocket engines, in particular to a flame afterburning device at the outlet of an exhaust cooling igniter. Background Art

[0002] The torch igniter for rocket engine can be divided into the emission cooling scheme and the film cooling scheme according to the thermal protection scheme. The emission cooling igniter fuel is divided into two paths. One path enters the igniter combustion chamber and mixes with the oxidizer to burn to form the central high-temperature combustion gas. The other path of fuel enters the cooling channel, cools the igniter matrix and then directly discharges out of the igniter. Only a small part of this part of fuel can be further mixed with the central high-temperature combustion gas under natural flow, and most of it is not fully utilized and directly flows to the downstream combustion device, which leads to low flame energy at the igniter outlet. On the other hand, since the cooling fuel and the central high-temperature combustion gas are not fully supplemented, the low-temperature cooling fuel will wrap the central high-temperature combustion gas, the igniter outlet flame temperature is extremely uneven, and the gas flow rate is high. Both aspects will have an adverse effect on the ignition of the downstream combustion device by the igniter. Summary of the invention

[0003] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and provide a device for supplementary combustion of the flame at the outlet of an exhaust cooling igniter, so that the high-temperature combustion gas in the center of the igniter and the cooling fuel can be fully supplementary burned, the energy of the flame at the outlet of the igniter can be increased, the stability of the flame at the outlet of the igniter can be enhanced, and thus the reliability of the igniter in igniting the rocket engine can be improved.

[0004] The technical solution of the present invention is: to provide a flame re-combustion device at the outlet of the emission cooling igniter, which is installed at the outlet of the emission cooling igniter. The upper end of the re-combustion device is a cone structure, the middle is a different-diameter cavity, and the lower end is an outlet. A plurality of axially symmetrically distributed injection holes are arranged on the cone according to the gas flow rate, and a vortex recirculation zone is formed in the different-diameter cavity; the top of the cone is directly opposite to the central high-temperature gas ejected from the emission cooling igniter, and the central high-temperature gas is guided by the conical surface and flows to the surroundings, and is preliminarily mixed with the cooling fuel flowing out of the cooling interlayer of the emission cooling igniter, and enters the cone cavity of the cone through the symmetrically distributed injection holes to impact and mix with each other, fully re-combust, and flow downstream into the different-diameter cavity, generating vortices in the vortex recirculation zone, reducing the velocity of the mixed gas, and flowing out from the outlet.

[0005] Furthermore, the sum of the cross-sectional areas of the injection holes is smaller than the cross-sectional area of ​​the outlet of the exhaust cooling igniter, thereby increasing the velocity of the mixed gas flow at the outlet of the injection holes and enhancing the mixing and afterburning capability.

[0006] Furthermore, the outlet diameter of the different-diameter cavity is smaller than the inlet diameter, and a trapped vortex recirculation zone is formed between the outlet and the inlet, thereby increasing the recirculation area and enhancing flame stability.

[0007] Furthermore, the cross-sectional area of ​​the outlet is smaller than the sum of the cross-sectional areas of the injection holes, ensuring that the minimum throttling area of ​​the discharge cooling igniter is at the outlet, and the mixing and supplementary combustion of the central high-temperature combustion gas and the cooling fuel occurs before the minimum throttling surface.

[0008] Furthermore, the different-diameter cavity adopts a cylindrical structure, the cylindrical inlet is integrally connected with the cone outlet, and the cylindrical outlet is integrally connected with the outlet inlet.

[0009] Furthermore, the top of the cone is designed to be a smooth transition structure.

[0010] Furthermore, multiple rows of injection holes are distributed along the longitudinal direction of the cone, and each row of injection holes is distributed in an axisymmetric manner.

[0011] Furthermore, the outlet is designed as a through hole.

[0012] Furthermore, 3D printing technology is used for integrated molding.

[0013] The advantages of the present invention compared with the prior art are:

[0014] (1) A cone structure is arranged at the top of the supplementary combustion device of the present invention, so that the high-temperature combustion gas at the center of the outlet of the exhaust cooling igniter flows to the surrounding areas through the cone surface and is initially mixed with the cooling fuel flowing at the periphery.

[0015] (2) The cone structure of the present invention is provided with a plurality of injection holes, which are arranged in multiple rows and are symmetrically distributed, so that the mixed gas flowing out of the injection holes can be impacted and mixed in the cone cavity to achieve sufficient mixing and secondary combustion; by designing the sum of the cross-sectional areas of the injection holes to be smaller than the cross-sectional area of ​​the outlet of the discharge cooling igniter, that is, n×d0 2 <d3 2 , increase the mixed gas flow velocity at the injection hole outlet and enhance the mixing and supplementary combustion effect.

[0016] (3) In the present invention, a different-diameter concave cavity structure is arranged at the middle end, and the mixed gas forms a local low-speed vortex recirculation zone in the concave cavity, thereby reducing the gas flow rate; by designing the concave cavity outlet diameter to be smaller than the inlet diameter, that is, d1<d2, the recirculation area is effectively increased and the flame stability is enhanced.

[0017] (4) The lower end of the present invention is designed as an outlet, and the outlet is a through hole; by designing the cross-sectional area of ​​the outlet to be smaller than the sum of the cross-sectional areas of the injection holes on the cone, that is, n×d0 2 >d2 2 , ensuring that the mixture is fully mixed and the re-ignition occurs upstream of the minimum throttle surface of the igniter, so that the combustion state of the igniter can be judged by the chamber pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the supplementary combustion device of the present invention;

[0019] Figure 2 It is a schematic diagram of the external airflow direction during the working process of the supplementary combustion device of the present invention;

[0020] Figure 3 It is a schematic diagram of the injection hole mixing and supplementary combustion method of the present invention;

[0021] Figure 4 It is a schematic diagram of the flame stabilization method of the different-diameter cavity of the present invention. DETAILED DESCRIPTION

[0022] In order to better understand the technical solution of the present invention, the embodiments of the present invention are specifically described below in conjunction with the accompanying drawings. The following description of the preferred implementation will involve a combination of features, which may exist independently or in combination, and the present invention is not particularly limited to the preferred implementation.

[0023] The exhaust cooling igniter outlet flame supplementary combustion device provided in this embodiment is formed in an integrated manner by 3D printing, and the structural cross-section diagram is shown in FIG. Figure 1 The device has a cone 1 structure at the upper end, and n injection holes 2 are arranged on the cone 1 according to the gas flow rate, a cavity 3 of different diameters is in the middle, and an outlet 4 is at the lower end. Preferably, the top of the cone 1 is designed as a smooth transition structure; multiple rows of injection holes 2 are distributed longitudinally along the cone 1, and each row of injection holes 2 is axially symmetrically distributed.

[0024] like Figure 2 As shown, the top of the cone 1 faces the central high-temperature combustion gas 7 of the discharge cooling igniter 5. The central high-temperature combustion gas 7 is guided by the conical surface and flows around. After the cooling fuel 6 comes out of the cooling interlayer of the discharge cooling igniter 5, it is diffused and preliminarily mixed with the central high-temperature combustion gas 7 flowing around.

[0025] like Figure 3 As shown, the mixture 8 of the cooling fuel and the central high-temperature combustion gas flows out through the symmetrically distributed injection holes 2, and then impacts and mixes in the carrier cone cavity, fully supplementary combustion, and forms a high-speed combustion gas 9 after mixed supplementary combustion. Preferably, the sum of the cross-sectional areas of the injection holes 2 is smaller than the outlet cross-sectional area of ​​the upstream discharge cooling igniter 5, that is, n×d0 2 <d3 2 This size characteristic can increase the mixed gas flow velocity at the outlet of the injection hole 2 and enhance the mixing and supplementary combustion effect.

[0026] like Figure 4As shown, the different-diameter cavity 3 adopts a cylindrical structure, the cylinder inlet is integrally connected with the cone 1 outlet, and the cylinder outlet is integrally connected with the outlet 4 inlet. The high-speed combustion gas 9 after mixed supplementary combustion forms a local low-speed vortex recirculation zone 10 in the different-diameter cavity 3, thereby reducing the gas flow rate. Preferably, the outlet diameter of the different-diameter cavity 3 is smaller than the inlet diameter, and a vortex recirculation zone 10 is formed between the outlet and the inlet, that is, d1<d2. This size characteristic can increase the recirculation area, thereby more effectively reducing the gas flow rate and enhancing flame stability. The outlet 4 at the lower end of the device is designed as a through hole with a diameter of d2. Preferably, the cross-sectional area of ​​the outlet 4 is smaller than the sum of the cross-sectional areas of the injection holes 2, that is, n×d0 2 >d2 2 This size characteristic can ensure that the minimum throttling area of ​​the exhaust cooling igniter 5 is at the outlet 4, and the complete mixing and re-combustion of the central high-temperature combustion gas 7 and the cooling fuel 6 occurs before the minimum throttling surface, so that the combustion state of the igniter can be judged by the exhaust cooling igniter 5 chamber pressure.

[0027] It is to be understood that the present invention is described by way of embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and embodiments that can fall within the scope of the claims of this application all fall within the scope protected by the present invention.

[0028] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A flame afterburning device at the outlet of a discharge cooling igniter, installed at the outlet of the discharge cooling igniter, characterized in that: The upper end of the afterburning device is a cone (1), the middle is a cavity of different diameters (3), and the lower end is an outlet (4). A plurality of injection holes (2) distributed axially symmetrically are arranged on the cone (1) according to the size of the gas flow rate, and a vortex recirculation zone (10) is formed in the cavity of different diameters (3); the top of the cone (1) faces the central high-temperature gas (7) ejected from the discharge cooling igniter (5), and the central high-temperature gas (7) is guided by the cone surface and flows in all directions, and is initially mixed with the cooling fuel (6) flowing out of the cooling interlayer of the discharge cooling igniter (5), and enters the cone cavity of the cone (1) through the symmetrically distributed injection holes (2) to impact and mix, fully afterburn, and flows downstream into the cavity of different diameters (3), generating a vortex in the vortex recirculation zone (10), reducing the velocity of the mixed gas, and flowing out from the outlet (4).

2. The exhaust cooling igniter outlet flame afterburning device according to claim 1, characterized in that: The sum of the cross-sectional areas of the injection holes (2) is smaller than the outlet cross-sectional area of ​​the discharge cooling igniter (5), thereby increasing the mixed gas flow velocity at the outlet of the injection holes (2) and enhancing the mixing and afterburning capability.

3. The exhaust cooling igniter outlet flame afterburning device according to claim 1, characterized in that: The outlet diameter of the different-diameter cavity (3) is smaller than the inlet diameter, and a trapped vortex recirculation area (10) is formed between the outlet and the inlet, thereby increasing the recirculation area and enhancing flame stability.

4. The exhaust cooling igniter outlet flame afterburning device according to claim 1, characterized in that: The cross-sectional area of ​​the outlet (4) is smaller than the sum of the cross-sectional areas of the injection holes (2), thereby ensuring that the minimum throttling area of ​​the discharge cooling igniter (5) is at the outlet (4), and that the mixing and supplementary combustion of the central high-temperature combustion gas (7) and the cooling fuel (6) occurs before the minimum throttling surface.

5. The exhaust cooling igniter outlet flame afterburning device according to claim 4, characterized in that: The different-diameter concave cavity (3) adopts a cylindrical structure, the cylindrical inlet is integrally connected with the cone (1) outlet, and the cylindrical outlet is integrally connected with the outlet (4) inlet.

6. The exhaust cooling igniter outlet flame afterburning device according to claim 1, characterized in that: The top of the cone (1) is designed as a smooth transition structure.

7. The exhaust cooling igniter outlet flame afterburning device according to claim 1, characterized in that: Multiple rows of injection holes (2) are distributed longitudinally along the cone (1), and each row of injection holes (2) is distributed in an axisymmetric manner.

8. The exhaust cooling igniter outlet flame afterburning device according to claim 1, characterized in that: The outflow port (4) is designed as a through hole.

9. The exhaust cooling igniter outlet flame afterburning device according to claim 1, characterized in that: Integrated molding using 3D printing technology.

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