CN114738795B - Support plate stabilizer with gas mixing function and integrated afterburner - Google Patents

Abstract

In order to solve the problems of insufficient combustion and increased difficulties in ignition and flame stabilization due to the forward movement of the recirculation zone and the combustion zone in the existing afterburner integration design scheme, the present invention proposes a support plate stabilizer with gas mixing function and integrated afterburner. The middle part of the support plate stabilizer of the present invention is provided with two symmetrical open concave cavities, the open concave cavities have gas mixing effect, can replace the mixer in the traditional afterburner, simplify the structure of the afterburner and because The outer air flow flows into the inner channel through the hole on the front wall of the open concave cavity and mixes with the inner air flow, which shortens the mixing distance of the inner and outer air flow, strengthens the mixing effect of the inner air flow and the outer air flow, and is beneficial to the fuel and air mixture at the rear In addition, because the oxygen content of the outer airflow is higher than that of the inner airflow, the oxygen content of the mixed air is increased after the two are mixed, and the outer airflow and the inner airflow are mixed while burning, making the combustion more efficient. Fully, improved flame stability and combustion efficiency.

Description

Support plate stabilizer with gas mixing function and integrated afterburner

technical field

The invention relates to the technical field of engines, in particular to a support plate stabilizer with an air mixing function and an integrated afterburner.

Background technique

The afterburner has been developed for about 80 years. Although the mass of the afterburner accounts for about 20% of the engine, it can greatly increase the thrust. Generally speaking, the thrust of the turbojet engine can be increased by 40% to 50% after the afterburner is turned on, and the thrust of the turbofan engine can even be increased by more than 70%. The increase in thrust leads to the improvement of flight maneuverability and the expansion of the flight envelope, so the development of the afterburner is very important for military fighters. The flame stabilizer in the traditional afterburner is directly installed in the main flow, and the airflow flows through the flame stabilizer, forming a recirculation zone behind it, which is used to organize combustion and improve the stability of the flame. But traditional flame holders can cause flow blockages, causing unavoidable flow losses.

In the 1990s, an integrated design scheme of the afterburner and the rear frame of the turbine was proposed internationally, and the rectifying strut and the flame stabilizer in the afterburner were integrated to form a strut stabilizer. This solution cancels the traditional flame stabilizer, which can effectively reduce flow blockage and flow loss. The fuel adopts the close fit technology, the fuel is sprayed laterally from both sides of the rectifying strut, and the flame is stabilized by using the recirculation area formed behind the rectifying strut. In this scheme, the recirculation area of the afterburner moves forward as a whole, and the combustion area also moves forward, but this forward movement is unfavorable for the afterburner. On the one hand, the oxygen content in the airflow is reduced, and the outer airflow with more oxygen in the afterburner and the inner airflow with less oxygen are mixed behind the mixer, and the combustion zone is moved forward so that the fuel starts to burn before the mixer , at this time, only the airflow with less oxygen content participates in the combustion, which is very unfavorable to the full combustion of the fuel; The uneven distribution of fuel mass in the recirculation zone behind the plate greatly increases the difficulty of ignition and flame stabilization. In addition, the outer side of the rectifying struts in this scheme is exposed to high-temperature internal airflow, and the temperature of the outer wall of the struts is high, and the thermal stress it bears is relatively large.

Contents of the invention

In order to solve the technical problems that the existing afterburner integrated design scheme makes the recirculation zone and the combustion zone move forward, which leads to insufficient combustion and greatly increases the difficulty of ignition and flame stability, the present invention proposes a support plate with gas mixing function Stabilizers and integrated afterburner. In the present invention, two open concave cavities are arranged in the middle of the support plate stabilizer, and the open concave cavities have the function of mixers, which can replace the mixers in the traditional afterburner; in addition, the open concave cavities On the one hand, the strut stabilizer can form front and rear channels to distribute the culvert airflow, and on the other hand, the culvert airflow can be introduced into the open cavity without increasing the blocking area of the strut plate, and at the same time, the open cavity is inclined The wall surface enables the outer culvert airflow to flow smoothly to the rear, and the outer culvert airflow is close to the outer wall surface of the support plate stabilizer, which can effectively cool the support plate stabilizer. Compared with the prior art, when the support plate stabilizer provided by the present invention is used to form the afterburner, the traditional flame stabilizer and the traditional mixer can be eliminated, reducing the number of components and the flow blocking loss of the airflow. In addition, the support plate stabilizer of the present invention enables the internal and external airflow to be mixed in advance at the open cavity, which increases the oxygen content of the combustion airflow in the recirculation area, and the turbulence of the airflow during the mixing process increases to improve the atomization of fuel The quality can effectively reduce the difficulty of ignition and flame stabilization, and improve flame stability and combustion efficiency.

Technical scheme of the present invention is:

The strut stabilizer with air mixing function is special in that it includes the front channel of the strut stabilizer, the connecting plate and the rear channel of the strut stabilizer connected in sequence along the airflow direction, and the rear channel of the front channel of the strut stabilizer The wall surface, the connecting plate, and the front wall of the rear channel of the support plate stabilizer jointly form two open concave cavities distributed symmetrically with respect to the connecting plate;

The front channel of the support plate stabilizer is provided with a partition for shunting, and the rear wall surface of the front channel of the support plate stabilizer is uniformly provided with a plurality of air holes for introducing the air flow into the open cavity along its length direction;

There are multiple uniformly distributed main fuel injection holes on the left and right side walls of the rear channel of the support plate stabilizer. In front of each main fuel injection hole, there is also a place for spraying air jets to slow down the main fuel injection holes. Jet holes for airflow velocity; multiple on-duty fuel injection holes for forming on-duty flames are evenly opened on the rear wall of the rear channel of the support plate stabilizer.

Further, a blunt body for rectification is provided on the upstream surface of the channel in front of the support plate stabilizer.

Further, the depth of a single open cavity is 1/3-2/5W, and the width is 3/5-1W; W is the width of the tail end of the support plate stabilizer.

Further, the air holes on the rear wall surface of the front channel of the support plate stabilizer are round holes; the diameter of the round holes is 3/20-1/4W, and the number is 8-12.

Further, the diameter of the main fuel injection hole is 0.5mm-2.0mm, and the number is 6-15; the diameter of the air injection hole is 1-2mm; the diameter of the duty fuel injection hole is 0.5mm-1.5mm , the number is 6-15.

Further, the blocking ratio of the support plate stabilizer is 0.25-0.30.

The present invention also provides an integrated afterburner, which includes an afterburner cylinder, a rear duct injector, a plurality of support plate stabilizers and a central cone arranged coaxially from outside to inside in sequence; The devices are radially distributed on the outer wall of the central cone along the circumference; the feature is that: the above-mentioned support plate stabilizer is adopted as the support plate stabilizer.

Further, the tail rear wall of the support plate stabilizer is provided with an inclination along the radial direction.

Further, the inclination angle is 60°-75°.

The beneficial effects of the present invention are:

1. Two symmetrical open concave cavities are arranged in the middle of the support plate stabilizer of the present invention. The open concave cavities have the effect of mixing gas and can replace the mixer in the traditional afterburner, thereby realizing the combination of the mixer and The integrated design of the strut stabilizer simplifies the structure of the afterburner and because the outer airflow flows into the inner channel through the holes on the front wall of the open concave cavity to mix with the inner airflow, compared with the existing afterburner, The mixing of internal and external airflows is advanced, shortening the mixing distance of internal and external airflows, and strengthening the mixing effect of internal and external airflows. At the same time, the heat and mass exchange between internal and external airflows during the mixing process increases the mixing efficiency The degree of turbulence is conducive to the mixing of fuel and mixed gas at the rear, and improves the uniformity of fuel distribution. In addition, because the oxygen content of the outer airflow is higher than that of the inner airflow, the oxygen content of the mixed air is increased after the two are mixed. The outer airflow and the inner airflow The internal airflow is mixed while burning, which makes the combustion more complete, thereby improving the flame stability and combustion efficiency.

2. The strut stabilizer of the present invention has the functions of rectification, gas mixing and flame stabilization, and can replace the turbine rectifying strut, mixer and flame stabilizer in the traditional afterburner, reducing the number of parts constituting the afterburner Quantity, reducing the complexity and additional mass of the system, increasing the compactness and shortening the length of the afterburner.

3. When using the support plate stabilizer of the present invention to form the afterburner, the traditional flame stabilizer can be eliminated, which reduces the flow blockage of the air flow and is beneficial to improve the total pressure recovery performance of the afterburner.

4. In the present invention, the fuel injection rod is arranged inside the rear channel of the support plate stabilizer, and the fuel injection rod is cooled by the culvert airflow entering the rear channel of the support plate stabilizer, which prevents fuel coking and component ablation, and improves the fuel injection rod. The service life and reliability; at the same time, the culvert airflow in the channel after entering the support plate stabilizer can reach the support plate, and the center cone is cooled, which improves the service life and reliability of the center cone.

5. The air jet flow of the injection hole can improve the penetration distance of fuel and the distribution of fuel quality; by reasonably controlling the opening and closing of the fuel injection hole of the support plate stabilizer, the switching from small afterburner to full afterburner is realized.

6. After the integrated afterburner of the present invention is assembled, the tail rear wall of the support plate stabilizer has a radial inclination relative to the horizontal surface, which promotes the flame to spread along the radial and axial directions on the basis of stable combustion of the flame, and realizes the intensification of the afterburner. The stable flame and joint flame of the combustion chamber form a good combustion organization, which is beneficial to the combustion and improves the combustion efficiency.

7. When the present invention is in operation, the external air flow flowing into the front channel of the support plate stabilizer is covered (or close to) on the outer surface of the support plate stabilizer after flowing out of the round hole, and it is isolated from the high-temperature incoming flow, which can effectively control the flow of the support plate stabilizer. plate stabilizer for cooling.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the afterburner integrated with the mixer and the support plate stabilizer.

Fig. 2 is a schematic structural view of the integrated afterburner central cone and support plate stabilizer.

Fig. 3 is an overall sectional view of the afterburner integrated with the mixer and the support plate stabilizer.

Fig. 4 is a structural schematic diagram of a support plate stabilizer.

Figure 5 is a schematic diagram of the air jet and fuel injection of the strut stabilizer.

Reference signs:

1- Afterburner cylinder, 2- Heat shield, 3- Rear duct ejector, 4- Support plate stabilizer, 5- Central cone, 6- Front blunt body, 7- Round hole, 8- Open concave Cavity, 9-jet small hole, 10-main fuel injection hole, 11-duty fuel injection hole, 12-branch plate stabilizer front channel, 13-branch plate stabilizer rear channel, 14-air jet, 15-main fuel oil, 16 - duty fuel.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing.

As shown in Figures 1-3, the afterburner integrated with the mixer and the support plate stabilizer provided by the present invention includes an afterburner cylinder 1 coaxially arranged in sequence from the outside to the inside, a rear duct ejector 3, Support plate stabilizer 4 and center cone 5. An external duct is formed between the booster cylinder 1 and the rear duct ejector 3 . An inner channel is formed between the rear duct ejector 3 and the central cone 5 . One end of the support plate stabilizer 4 is connected with the rear duct ejector 3 , and the other end is connected with the central cone 5 . A heat shield 2 is also arranged between the booster cylinder 1 and the support plate stabilizer 4, one end of the heat shield 2 is connected to the tail end of the rear duct ejector 3, and there is a Clearance for airflow through the bypass.

As shown in Figure 4, there are a plurality of strut stabilizers 4, which are distributed radially on the outer wall of the central cone 5 along the circumference; The front channel 12 of the support plate stabilizer, the connecting plate and the rear channel 13 of the support plate stabilizer connected in sequence in the airflow direction, and the rear wall surface of the front channel 12 of the support plate stabilizer, the connecting plate, and the front wall surface of the rear channel 13 of the support plate stabilizer are common An open concave cavity 8 is formed, and there are two open concave cavities 8, which are symmetrically distributed on the left and right sides of the connecting plate; the front channel 12 of the support plate stabilizer and the rear channel 13 of the support plate stabilizer are ejected from the rear duct The air flow channel that device 3 extends toward center cone 5 direction; Also be provided with the dividing plate that is used for shunting in the front channel 12 of strut plate stabilizer, make the air flow of outer culvert flow into two openings more evenly from the rear wall of front channel 12 of strut plate stabilizer In the concave cavity 8; On the rear wall surface of the front channel 12 of the support plate stabilizer (that is, the front wall surface of the open concave cavity 8), a plurality of circular holes 7 are evenly opened along its length direction (in other embodiments, it is also possible to Adopt other forms of holes, but the flow loss of the round hole is the smallest), the outer air flow in the front channel 12 of the strut plate stabilizer can enter the connotation through the round hole 7, to mix with the inner air flow and participate in subsequent combustion; the strut plate stabilizer The rear passage 13 is provided with an air passage and an oil passage. The air passage is an external air flow passage connected to the center cone 5. The oil passage includes the main fuel oil passage and the on-duty fuel oil passage; Both side walls are provided with a plurality of straight-type main fuel injection holes 10 uniformly distributed along the length direction, and an air injection hole 9 is also provided in front of each main fuel injection hole 10, and the air injection hole 9 is used to eject air jets. The direction of the air jet is perpendicular to the internal airflow, which can slow down the airflow velocity at the position of the main fuel injection hole 10, increase the penetration distance of the fuel, improve the distribution of the fuel, and make the fuel diffuse and burn on both sides of the support plate stabilizer, forming a main Flame; the rear wall surface of the rear channel 13 of the support plate stabilizer is evenly opened with a plurality of direct-type on-duty fuel injection holes 11 along the length direction, and the fuel injection holes 11 can inject fuel into the backflow area behind the support plate stabilizer to form an on-duty flame , improve flame stability.

The central cone 5 is a typical part in the afterburner, which is used for the deceleration and diffusion of the internal airflow, and is an existing unit.

In order to promote the radial and axial propagation of the flame, realize the afterburner, and form a good combustion structure, the present invention, when assembling the support plate stabilizer, installs the rear wall of the rear part (the rear wall where the direct-type duty fuel injection hole 11 is located) ) along the radial direction to set a certain inclination angle, because the inclination angle affects the flame propagation effect, after a large number of experiments, the inclination angle is preferably 60°-75°.

In order to rectify the high-speed incoming flow, the present invention also sets a blunt body 6 at the front end of the support plate stabilizer to change the flow direction of the high-speed incoming flow (contained airflow) to achieve the rectification effect.

Preferably: the depth of a single open concave cavity 8 on each support plate stabilizer of the present invention is 1/3-2/5W, and the width is 3/5-1W; The diameter of the round hole 7 offered on the open concave cavity 8 (front wall) is 3/20-1/4W, and the number is 8-12; Width, as shown in Figure 5; 6-15 main fuel injection holes 10 with the same specifications and the same number of the same size and number as the diameter of 0.5mm-2.0mm are set on the left and right side walls of the rear channel 13 of the support plate stabilizer to ensure the support The combustion organization on both sides of the plate stabilizer is similar to ensure the combustion stability of afterburner; the aperture of the jet hole 9 offered in the front of the main fuel injection hole 10 is 1-2mm, the number is equal to the main fuel injection hole 10, and the position is the same as that of the main fuel injection hole 10. The main fuel injection holes 10 correspond one-to-one (the role of the small jet hole is to increase the penetration depth of the main fuel, and the longer fuel injection distance can improve the uniformity of fuel distribution, which is beneficial to the atomization and evaporation of fuel; but the small jet If the number of holes is too large, the effect on the fuel penetration distance is not obvious and will increase the total pressure loss); on the rear wall of the rear channel 13 of the support plate stabilizer, 6-15 on-duty fuel oil holes with a diameter of 0.5mm-1.5mm are provided. Injection hole 11; set the ratio of the area of the internal flow channel blocked by the support plate stabilizer as the blockage ratio of the support plate stabilizer. Under the condition of ensuring the recovery performance of the total pressure, the blockage ratio of the support plate stabilizer is designed to be 0.25-0.30. The blockage ratio of the range is more appropriate in terms of the benefit trade-off between the total pressure loss and the size of the recirculation zone.

Principle of the present invention is:

The external air flow flows into the afterburner chamber axially from the external duct formed by the afterburner cylinder 1 and the rear duct ejector 3, and the external air flow is used to participate in combustion, cool and provide the air ejected from the air injection hole 9 jet.

The culvert airflow flowing into the afterburner is divided into four paths: one culvert airflow flows into the strut stabilizer 4 through the front channel 12 of the strut stabilizer, and mainly participates in combustion; the second culvert airflow passes through the rear channel of the strut stabilizer 13 flows into the support plate, which is used to cool the central cone 5 and provide air jets for the jet holes 9; the third external air flow flows in from the channel between the afterburning cylinder 1 and the heat shield 2, and is used to cool the heat shield 2 ; The fourth channel external airflow flows into the combustion zone through the small hole on the heat shield 2, which is used to improve the ignition conditions.

The internal air flow flows into the afterburner from the internal channel formed by the rear duct ejector 3 and the central cone 5 , and is rectified under the action of the support plate stabilizer 4 .

After entering the front channel 12 of the support plate stabilizer, the outer culvert airflow that mainly participates in combustion is divided into two parts by the partition inside it, so as to ensure that the outer culvert airflow passes from the circle on the front wall surface of the open concave cavity 8 that is symmetrically distributed in Fig. 4 . The hole 7 flows out evenly, and the outer airflow flowing out from the round hole 7 is mixed with the inner airflow rectified by the front blunt body 6 at the open concave cavity 8 on the support plate stabilizer 4, which shortens the airflow mixing distance and the mixing process The heat and mass exchange between the two air streams increases the turbulence of the gas mixture and accelerates the subsequent mixing of oil and gas, thereby improving the uniformity of fuel oil distribution and improving combustion efficiency.

The outer culvert airflow used to cool the central cone 5 and provide the air jet flows in from the rear channel 13 of the support plate stabilizer, and a part of the outer culvert air flow flows into the center cone 5 at the bottom of the support plate stabilizer 4 along the rear channel 13 of the support plate stabilizer. To cool the center cone 5 walls, another part of the external air flow is ejected from the jet hole 9 in Fig. 4 to form the air jet 14 shown in Fig. 5; The jet flow direction of the jet hole 9 is perpendicular to the wall surface, and the air jet flow 14 interacts with the internal incoming flow, slowing down the air velocity at the main fuel injection hole 10, reducing the tangential velocity component of the main fuel oil 15, thereby increasing the penetration of the main fuel oil. Penetration depth and injection distance, longer injection distance will improve the uniformity of fuel distribution, which is conducive to fuel atomization and evaporation.

The evenly mixed mixed airflow and duty fuel oil 16 are burned in the low-velocity recirculation zone behind the support plate stabilizer 4 to form duty flames, which is conducive to flame stability. At the same time, the duty flames spread radially and axially along the rear wall of the support plate stabilizer 4 , Realize flame joint flames, form a good combustion organization, make the mixed gas fully combustible, and improve combustion efficiency.

By reasonably controlling the opening and closing of the fuel injection hole 11 on the support plate stabilizer 4, the working mode transition from small afterburner to full afterburner can be realized: when the light afterburner is turned on, the support plate stabilizer 4 in Fig. The on-duty fuel injection holes 11 on the rear wall are all opened, and the main fuel injection holes 10 on both side walls are all closed; The fuel injection holes 11 on duty on the injection hole 10 and the rear wall are all opened.

Claims (9)

1. Support plate stabilizer with mix gas function, its characterized in that: the support plate stabilizer comprises a support plate stabilizer front channel, a connecting plate and a support plate stabilizer rear channel which are sequentially connected along the air flow direction, wherein two open cavities which are symmetrically distributed relative to the connecting plate are formed by the rear wall surface of the support plate stabilizer front channel, the connecting plate and the front wall surface of the support plate stabilizer rear channel;

a baffle plate for shunting is arranged in the front channel of the support plate stabilizer, and a plurality of air holes for introducing air flow in the front channel of the support plate stabilizer into the open type concave cavity are uniformly formed in the rear wall surface of the front channel of the support plate stabilizer along the length direction of the front channel; the front channel of the support plate stabilizer is used for enabling one path of external air flow to flow into the support plate stabilizer from the front channel of the support plate stabilizer and flow into the two open cavities through the air holes formed in the rear wall surface of the front channel of the support plate stabilizer;

a plurality of uniformly distributed main fuel injection holes are formed in the left side wall and the right side wall of the back channel of the support plate stabilizer, and an air injection hole for injecting air jet flow to slow down the air flow speed at the position of the main fuel injection hole is formed in front of each main fuel injection hole; a plurality of duty fuel injection holes for forming duty flames are uniformly formed on the rear wall surface of the rear channel of the support plate stabilizer; the back channel of the support plate stabilizer is used for enabling one path of external air flow to flow into the support plate stabilizer so as to cool the center cone and provide air jet flow for the air jet holes.

2. The branching plate stabilizer with a gas mixing function as set forth in claim 1, wherein: and a blunt body for rectification is arranged on the flow facing surface of the front channel of the support plate stabilizer.

3. The branching plate stabilizer with a gas mixing function according to claim 1 or 2, characterized in that: the depth of each open concave cavity is 1/3-2/5W, and the width is 3/5-1W; w is the width of the tail end of the support plate stabilizer.

4. A strip stabilizer with air mixing function according to claim 3, characterized in that: the air holes on the back wall surface of the front channel of the support plate stabilizer are round holes; the diameter of the round holes is 3/20-1/4W, and the number of the round holes is 8-12.

5. The branching plate stabilizer with a gas mixing function as set forth in claim 4, wherein: the aperture of the main fuel injection hole is 0.5mm-2.0mm, and the number of the main fuel injection holes is 6-15; the aperture of the air injection hole is 1-2mm; the aperture of the fuel injection hole on duty is 0.5mm-1.5mm, and the number of the fuel injection holes is 6-15.

6. The branching plate stabilizer with a gas mixing function as set forth in claim 5, wherein: the blocking ratio of the support plate stabilizer is 0.25-0.30.

7. The integrated afterburner comprises an afterburner body, a rear duct ejector, a plurality of support plate stabilizers and a center cone which are coaxially arranged from outside to inside in sequence; the plurality of support plate stabilizers are distributed on the outer wall of the central cone in a radial manner along the circumference; the method is characterized in that: the strut stabilizer adopts the strut stabilizer of any one of claims 1 to 6.

8. The integrated afterburner of claim 7, wherein: the rear wall of the tail part of the support plate stabilizer is provided with an inclination angle along the radial direction.

9. The integrated afterburner of claim 8, wherein: the inclination angle is 60-75 degrees.

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