CN113048513B

CN113048513B - Multistage oil spout hole center cone integration afterburner

Info

Publication number: CN113048513B
Application number: CN202110422656.2A
Authority: CN
Inventors: 张群; 王紫欣; 高耀红; 马晓曦; 王晓燕
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2021-04-14
Filing date: 2021-04-14
Publication date: 2022-07-01
Anticipated expiration: 2041-04-14
Also published as: CN113048513A

Abstract

The invention provides an integrated afterburner with a multi-stage oil injection hole and a central cone, wherein the central cone is provided with a multi-stage oil injection hole, the central cone is hollow and is in a step shape, the step-shaped central cone structure increases the surface area of heat exchange between high-temperature fuel gas and fuel oil in a fuel oil channel, impact heat exchange is formed at the step position, the heat exchange is enhanced, and because of the multi-stage central cone structure, the high-temperature fuel gas can form an angular vortex between each two stages of sudden expansion when flowing through, and a more obvious backflow area is generated at the downstream. The nozzle opening blowout of arranging on the fuel oil that is preheated in the center cone fuel oil passageway passes through multistage center cone, at the low reaches burn, inclined plane between every two-stage makes the fuel oil form the pre-filming above that, when the nozzle opening blowout fuel oil of next-level, this liquid film can be by the breakage, form secondary atomization, further improve atomization effect and oil-gas mixture homogeneity degree, and then improved combustion efficiency, multistage center cone structure also helps forming the stable burning in the recirculation zone at afterburner center.

Description

Multistage oil spout hole center cone integration afterburner

Technical Field

The invention belongs to the field of gas turbine engines, and particularly relates to a multistage oil spray hole and central cone integrated afterburner.

Background

A particular aircraft engine cannot provide excellent performance over the entire thrust range. For example, an aircraft needs much more thrust during takeoff than during cruising, if the engine is designed according to the takeoff thrust, the mass of the engine is too large, and the performance of the engine is poor due to the fact that the engine is in a non-design point state during cruising; if the engine is designed to cruise thrust, the aircraft may not take off properly. One of the measures for solving the problems is to increase an afterburner between a gas turbine and a nozzle of the engine so as to greatly improve the thrust of the engine in a short time. Although the mass of the afterburner is only about 1/5 of the engine, the thrust can be increased by more than 60%. At present, the new generation military engines of all countries in the world basically adopt a structure with an afterburner.

Afterburners are important components of aircraft engines. Although the mass of the engine is only about 20% of the total mass of the engine, the thrust of the engine can be greatly increased. The afterburner is arranged between the turbine and the tail nozzle, and fuel oil is re-injected and then combusted by using the residual oxygen in the exhaust gas of the combustor, so that the possibility of increasing the thrust of the aircraft engine is provided. However, the afterburner utilizes the fuel gas from the main combustor to perform oil injection and re-combustion, and the oxygen content in the fuel gas flow is only about 2/3-3/4 of normal air, so the combustion efficiency is low. In addition, because the afterburner mostly adopts a direct injection type nozzle, fuel is directly injected into airflow, the fuel atomization effect is poor, the fuel is not uniformly mixed with the airflow, and the combustion efficiency is further reduced.

The afterburner has poor working environment, and the gas discharged from the outlet of the turbine has high temperature, low pressure and high speed, so that the gas is not beneficial to ignition and tissue combustion in the afterburner. In general, a bluff body structure is adopted as a flame stabilizer in a traditional afterburner, and a stable low-speed backflow zone behind the bluff body is utilized to ignite mixed gas and organize combustion. Along with the continuous improvement of the total inlet temperature of an afterburner of an engine, the working environment in the afterburner is worse, and the problems of fuel spontaneous combustion, high temperature resistance, structural reliability and the like of parts such as an oil injection rod, a blunt body flame stabilizer and the like are more obvious.

Disclosure of Invention

The invention aims to solve the technical problem of providing a multi-stage oil spray hole and center cone integrated afterburner, compared with the prior art, the multi-stage afterburner has the advantages that a diffuser-center cone-oil spray hole integrated design is adopted, a multi-stage direct injection type nozzle is arranged on the center cone, the center cone is hollow and stepped, when fuel enters a fuel channel in the center cone, the fuel can be preheated through high-temperature fuel gas combusted at the upstream, the stepped center cone structure increases the surface area of heat exchange between the high-temperature fuel gas and the fuel in the fuel channel, impact heat exchange is formed at the step, heat exchange is enhanced, the fuel channel in the multi-stage oil spray hole and center cone is in a contraction shape, the cross section area of the fuel channel is gradually reduced, the pressure is gradually increased, the particle size of sprayed liquid drops is reduced, and fuel atomization is facilitated. The nozzle opening blowout of arranging on the fuel that is preheated passes through multistage center awl, downstream burns, because multistage center awl structure, high temperature gas can form the angle vortex between every two-stage suddenly expanding when flowing through, produce the more obvious recirculation zone of more and the region that torrent intensity is bigger at downstream, inclined plane between every two-stage makes the fuel form the pre-filming on it, when the nozzle opening blowout fuel of next stage, this liquid film can be broken, form the secondary atomization, further improve atomization effect and oil-gas mixture homogeneous degree, and then improved combustion efficiency, multistage center awl structure also helps forming recirculation zone stable combustion at afterburning chamber center.

Technical scheme

The invention aims to provide an integrated afterburner with a multi-stage oil injection hole and a central cone.

The technical scheme of the invention is as follows:

the utility model provides a multistage nozzle opening center awl integration afterburner which characterized in that: the multi-stage oil injection hole and center cone integrated afterburner comprises an inner casing, an outer casing, a rectifying support plate structure, a multi-stage center cone, a multi-stage oil injection hole in the center cone, a graded tapered fuel oil channel in the center cone, a sudden expansion structure between each stage of the center cone and an inclined plane between each two stages; the inner casing and the outer casing of the structure are of a casing structure of a conventional afterburner, the rectifying support plates are positioned between and connected with the inner casing and the central cone and are distributed circumferentially, the number of the rectifying support plates is 10-20, and fuel channels are arranged in the rectifying support plates and connected with fuel entering the combustor; the multistage central cones connected with the rectifying support plate are in a step shape, the number of the steps is 3-5, the multistage central cones are positioned at the circumferential center of the whole afterburner, the axial direction is at the upstream position of the combustor, a sudden expansion structure can be formed between every two stages of the central cones due to different heights, an inclined plane is arranged between every two stages of the central cones, the length of the inclined plane is 30-80 mm, the included angle between the inclined plane and the axial direction is 30-60 degrees, a graded tapered fuel channel is arranged in the central cones, fuel injection holes are arranged on the surface of each stage of the central cones, so that the surface of each central cone forms a multistage fuel injection hole structure, and the diameter of each fuel injection hole is 1-4 mm; the fuel enters the center cone from the fuel channel inside the rectifying support plate, under the action of the graded tapered fuel channel inside the center cone, the particle size of the fuel sprayed from each stage of fuel spray holes is reduced, a film is pre-formed on the inclined plane between each two stages, the liquid film is further broken under the action of the fuel sprayed from the next stage to form secondary atomization, and the sudden expansion structure between each stage is beneficial to forming angular vortex to realize flame stabilization.

The integrated afterburner with the multi-stage oil injection hole and the central cone is characterized in that: the central cones are in a stepped form at the downstream part, the number of the central cones is 3-5, and a sudden expansion type structure is formed between the central cones of each stage due to different heights. The integrated afterburner with the multi-stage oil injection hole and the central cone is characterized in that: establish multistage nozzle opening on multistage center awl, this multistage nozzle opening center awl structure nozzle opening diameter is 1 ~ 4mm, and the length on inclined plane is 30 ~ 80mm between every two-stage, and inclination and axial direction contained angle are 30 ~ 60. The oil injection holes are uniformly distributed on each stage along the circumferential direction, the oil injection holes are distributed in a staggered manner from stage to stage, and a single row or multiple rows of injection holes can be arranged on each stage. And the fuel oil channel inside the center cone of the multi-stage fuel spray hole is in a contraction shape, and the cross-sectional area of the fuel oil channel flowing through is gradually reduced.

The invention has the following beneficial effects:

the integrated afterburner designed by the scheme has the advantages that the front side of the traditional central cone is provided with a plurality of stages of oil spray holes to form a hollow and step-shaped multi-stage central cone, so that fuel oil can be contacted with more high-temperature fuel gas to obtain better atomization effect, meanwhile, the multi-stage central cone structure is beneficial to the formation of a central reflux area, a sudden expansion structure is arranged between every two stages, the high-temperature fuel gas is beneficial to speed reduction and pressurization, oil injection holes are uniformly distributed on each stage of central cone, the disturbance of the central air flow can be enhanced, so that the retention time of the fuel oil mixed gas in the area is longer, the mixing is more uniform, the inclined surface between every two stages enables the fuel oil to form a pre-film on the inclined surface, when the fuel oil is sprayed out from the next stage of fuel spray hole, this liquid film can be broken, forms the secondary atomization, further improves atomization effect and oil-gas mixture homogeneous degree, and then has improved combustion efficiency.

Drawings

FIG. 1: integral structure schematic diagram of multistage oil spray hole center cone integrated afterburner

FIG. 2: structure schematic diagram of multi-stage fuel spray hole center cone and rectifying support plate

FIG. 3: enlarged view of part A of multi-stage oil spray hole central cone in figure 2

FIG. 4: left view of multi-stage oil spray hole center cone and rectification support plate structure

FIG. 5: right view of integral structure of multistage oil spray hole and central cone integrated afterburner

FIG. 6: right view of multi-stage oil spray hole center cone and rectifying support plate structure

FIG. 7: enlarged view of part B in FIG. 6

In the figure: 1-rectifying support plate, 2-multi-stage central cone, 3-oil spray hole, 4-sudden expansion structure and 5-inclined plane

Detailed Description

The invention will now be further described with reference to the accompanying drawings in which:

fig. 1 is a schematic view of an overall structure of a multi-stage fuel injection hole center cone integrated afterburner, fig. 2 is a schematic view of a multi-stage fuel injection hole center cone and a rectifying support plate, fig. 3 and fig. 4 are respectively an enlarged view of a part a of the multi-stage fuel injection hole center cone in fig. 2 and a left side view of the multi-stage fuel injection hole center cone and the rectifying support plate, so that it can be seen that a layout mode of the center cone structure is used for determining the size, distribution mode and relative position of fuel injection holes, fig. 5 is a right side view of the overall structure of the multi-stage fuel injection hole center cone integrated afterburner, fig. 6 and fig. 7 are respectively a right side view of the multi-stage fuel injection hole center cone and the rectifying support plate and an enlarged view of a part B in fig. 6.

The air current that comes by interior outer duct mixes between rectification extension board flame stabilizer blade to through the sudden expansion structure 4 that expands between every two-stage of the central awl of fig. 2 to carry out speed reduction and pressure boost to high temperature gas, the fuel nozzle 3 has evenly been arranged on every grade of this multistage central awl, and the fuel that preheats through high temperature gas passes through fuel nozzle 3 blowout and forms the precoat on inclined plane 5 of below, and the fuel liquid film can be broken under the fuel effect of next stage fuel nozzle blowout and form the secondary atomizing. Due to the hierarchical structure of the central cone, the mixed gas of the inner duct part and the outer duct part can be sucked to the central area by entrainment after flowing through the rectification support plate, a powerful backflow area is formed, the disturbance of the air flow can be further increased due to the existence of the oil spray holes, the oil-gas atomization effect is good, and the combustion efficiency and the combustion stability are improved.

Claims

1. The utility model provides a multistage nozzle opening center awl integration afterburner which characterized in that: the multistage oil spray hole and center cone integrated afterburner comprises an inner casing, an outer casing, a rectifying support plate structure and a multistage center cone, wherein the multistage center cone is provided with a multistage oil spray hole, a graded tapered fuel oil channel inside the multistage center cone, a sudden expansion structure between each stage of the multistage center cone and an inclined plane between each two stages; the inner casing and the outer casing of the structure are of a casing structure of a conventional afterburner, the rectifying support plates are positioned between and connected with the inner casing and the multi-stage central cone and are circumferentially distributed, the number of the rectifying support plates is 10-20, and fuel oil channels are arranged in the rectifying support plates and connected with fuel oil entering the combustor; the multistage central cone connected with the rectifying support plate is in a step shape, the number of stages is 3-5, the multistage central cone is located at the circumferential center of the whole afterburner, the axial direction is at the upstream position of the combustor, a sudden expansion structure can be formed between each two stages of the multistage central cone due to different heights, an inclined plane is arranged between each two stages of the multistage central cone, the length of the inclined plane is 30-80 mm, the included angle between the inclined plane and the axial direction is 30-60 degrees, a graded tapered fuel oil channel is arranged in the multistage central cone, each stage surface of the multistage central cone is provided with an oil injection hole, so that a multistage oil injection hole structure is formed on the surface of the multistage central cone, and the diameter of the oil injection hole is 1-4 mm; the fuel oil enters the multi-stage central cone from the fuel oil channel in the rectifying support plate, under the action of the graded tapered fuel oil channel in the multi-stage central cone, the particle size of the fuel oil sprayed from each stage of fuel oil spray holes is reduced, a film is pre-formed on the inclined surface between each two stages, the film is further broken under the action of the fuel oil sprayed from the next stage to form secondary atomization, and the sudden expansion structure between each stage is beneficial to forming angular vortex to realize flame stabilization.

2. The integrated afterburner with the multi-stage oil injection hole and the central cone is characterized in that: the oil spout hole is evenly arranged along circumference on every level, and crisscross distribution between the level sets up single row or multirow jet orifice on every level.

3. The integrated afterburner with the multi-stage oil injection hole and the central cone is characterized in that: the fuel oil channel inside the center cone of the multi-stage fuel spray hole is in a contraction shape, and the cross-sectional area through which the fuel oil channel flows is gradually reduced.