Improved APU flame tube inner and outer ring cooling device

Abstract

The application provides an improved APU flame tube inner and outer ring cooling device and relates to the technical field of aero-engines. The improved APU flame tube inner and outer ring cooling device comprises a combustion chamber case and a cylinder. According to the application, cooling air flows through the annular discharge port to form an annular cooling air film, which forms a complete protection structure for the inner side wall of the inner cylinder, effectively avoids the formation of a relatively obvious temperature difference area on the inner side wall of the cylinder, thereby avoiding the excessive thermal stress of the cylinder and the resulting cracks, chipping, deformation and other faults, and a wind collector is arranged on the outer ring sleeve. By arranging the wind collector, the flow of the cooling air flowing into the first gas hole can be accurately controlled. By arranging a transition arc on the inner side wall of the second guide ring and setting the inclination angles of the first conical surface section and the second conical surface section, the cooling air flowing out of the annular discharge port can be made to be as close as possible to the inner side wall of the cylinder located behind the annular discharge port, thereby avoiding being blown away by the high-temperature combustion gas and forming an effective annular cooling air film.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of an aero-engine, in particular to an improved APU flame tube inner and outer ring cooling device. BACKGROUND

[0002] With the increase of the thrust-to-weight ratio of an aero gas turbine engine, the combustion chamber design develops towards high temperature rise and high heat capacity, the combustion temperature in a modern aero-engine combustion chamber is as high as 2000 degrees Celsius or above, and the pressure is as high as 30 atmospheres. As a place for organizing combustion, the flame tube body works in a high-temperature and high-pressure environment for a long time, and has to bear a large thermal stress, creep stress and fatigue stress, so the service life and reliability of the flame tube become one of the key components that determine the service life and reliability of the engine. The flame tube body is generally made of high-temperature resistant alloy, but the current metal material temperature resistance is below 1000 degrees Celsius, which is far lower than the gas temperature; and according to the temperature resistance level of the metal material in recent decades, the temperature resistance level is far lower than the increase speed of the gas temperature, so it is necessary to effectively cool the flame tube by simply relying on the material for heat protection.

[0003] At present, the commonly used cooling technology for the wall surface of the flame tube mainly includes convection cooling (including impact cooling) and gas film cooling. However, in a high thrust-to-weight ratio engine, the intensified cooling of the wall surface of the high temperature rise and high heat capacity combustion chamber faces a very prominent contradiction: on the one hand, the increase of the combustion chamber temperature rise causes the amount of air participating in combustion to increase, thereby reducing the amount of air used for cooling; on the other hand, the increase of the outlet temperature of the compressor causes the temperature of the air used for cooling the wall surface of the flame tube to rise, thereby reducing the cooling potential, so that higher requirements are put forward for the cooling technology of the wall surface of the flame tube, and it is particularly important and urgent to improve the cooling efficiency of the cooling air, which must be solved by adopting an innovative technology.

[0004] In addition, the main factor affecting the service life of the flame tube is the thermal stress. Therefore, when the cooling technology is implemented, not only the temperature of the wall surface of the flame tube should be reduced, but also the temperature gradient of the wall surface of the flame tube should be reduced to prevent the wall surface of the flame tube from cracking, chipping, deforming and other faults caused by excessive thermal stress due to excessive temperature gradient. In order to further improve the wall surface cooling effect of the combustion chamber flame tube, researchers at home and abroad have developed various cooling methods, which undoubtedly improve the cooling effect. However, a common problem of these cooling structures is that the consumption of cooling air is too large, and the temperature distribution of the flame tube is not uniform enough, thereby causing a large thermal stress. Therefore, how to carefully tap the cooling capacity of the cooling air and reduce the thermal stress of the flame tube plate has become a challenge for the existing technology.

[0005] For this purpose, the market has disclosed a kind of cooling structure of aero-engine combustion chamber flame tube, comprising flame tube wallboard, the flame tube wallboard includes outer wallboard and inner wallboard, and a plurality of divergent holes are provided on the inner wallboard, and a plurality of impact holes are provided on the outer wallboard, each divergent hole, impact hole is distributed in the form of staggered, and the inner wallboard and the outer wallboard are connected by a plurality of spoiler columns;The flame tube wallboard is divided into two parts along the axial direction, which are the front section flame tube wallboard close to the high temperature area of the combustion chamber and the rear section flame tube wallboard away from the high temperature area of the combustion chamber;The diameter of the front section impact hole on the front section flame tube wallboard is greater than the diameter of the rear section impact hole on the rear section flame tube wallboard, and the diameter of the front section divergent hole on the front section flame tube wallboard is greater than the diameter of the rear section divergent hole on the rear section flame tube wallboard.Therefore, the present application improves the traditional flame tube wall cooling structure, fully explores the cooling potential under the premise of not increasing the cold gas amount, improves the cooling efficiency, and avoids the excessive thermal stress caused by the high temperature of the flame tube wall surface and the uneven distribution;

[0006] The above-mentioned disclosed technology divides the flame tube cooling part into front and rear sections, changes the cooling effect by different impact hole diameters of the front and rear sections to solve the problem of uneven temperature distribution of the flame tube wall, in fact, the gas flow entering the inside of the flame tube through the impact hole is difficult to form a uniform cooling gas film on the inside wall of the flame tube when it is carried by the high-temperature gas, that is, it cannot completely cover the inside wall of the flame tube, which results in that the inside wall of the flame tube forms a relatively obvious temperature difference area after long-term use, causes excessive thermal stress of the flame tube, and thus causes cracks, chipping, deformation and other faults of the flame tube, therefore, it is necessary to optimize and improve the structure of the flame tube cooling device. SUMMARY

[0007] (I) Technical problems to be solved

[0008] In view of the deficiencies of the prior art, the present application provides an improved APU flame tube inner and outer ring cooling device, which solves the problem that the cooling gas film on the inside wall of the flame tube is difficult to completely cover the inside wall of the flame tube in the prior art, which results in that the inside wall of the flame tube forms a relatively obvious temperature difference area after long-term use, causes excessive thermal stress of the flame tube, and thus causes cracks, chipping, deformation and other faults of the flame tube.

[0009] (II) Technical solutions

[0010] In order to achieve the above object, the present application is realized by the following technical scheme: An improved APU flame tube inner and outer ring cooling device, comprising a combustion chamber case, a cylinder body, the combustion chamber case is provided with an air inlet and an air outlet at the front and rear ends respectively, the cylinder body is arranged inside the combustion chamber case, the cylinder body and the combustion chamber case are fixedly connected through a plurality of front and rear distributed support rings, an annular channel is formed between the cylinder body and the combustion chamber case, the plurality of support rings are each composed of a concentrically arranged inner ring plate, an outer ring plate and a plurality of support plates arranged between the inner ring plate and the outer ring plate, the outer wall of the outer ring plate of the support ring is fixedly connected with the inner side wall of the combustion chamber case, the outer wall of the cylinder body is fixedly connected with the inner side wall of the inner ring plate of the support ring, the plurality of support plates are circumferentially divided around the support ring axis, the cylinder body is composed of a concentrically arranged outer ring sleeve and an inner ring sleeve, the outer ring sleeve and the inner ring sleeve are fixedly connected through a plurality of support columns, an impact cavity is formed between the outer ring sleeve and the inner ring sleeve, the outer wall of the outer ring sleeve is provided with a plurality of first gas holes penetrating in and out, the outer wall of the inner ring sleeve is provided with a plurality of second gas holes penetrating in and out, the outer wall of the outer ring sleeve is provided with a wind collector for introducing part of the gas in the annular channel into the first gas hole and the impact cavity, and the inner side wall of the inner ring sleeve is provided with a gas guide structure for guiding the gas towards the inner side wall of the inner ring sleeve when the gas in the impact cavity enters the inner side wall from the second gas hole.

[0011] Preferably, the outer wall of the outer ring sleeve is provided with a first ring groove, the first gas hole is arranged in the inner side wall of the first ring groove, the first ring groove is penetrated through the first gas hole and the impact cavity, and the wind collector is arranged in the inner side wall of the first ring groove and located at the rear side of the first gas hole.

[0012] Preferably, the inner side wall of the inner ring sleeve is provided with a second ring groove, the second gas hole is arranged inside the second ring groove, the second ring groove is penetrated through the second gas hole and the impact cavity, and the gas guide structure is arranged in the inner side wall of the second ring groove.

[0013] Preferably, when the cylinder body is unfolded, a plurality of the first gas holes are partially coincident with one of a plurality of the second gas holes respectively, the first gas hole and the second gas hole are both inclined holes, the axes of the corresponding first gas hole and second gas hole are opposite, the angle between the axis extension line of the first gas hole and the second gas hole and the cylinder body axis is thirty-five degrees, the diameters of the first gas hole and the second gas hole are equal, the diameter of the first gas hole is three-fifths of the width of the first ring groove, and the diameter of the second gas hole is three-fifths of the width of the second ring groove.

[0014] Preferably, when the cylinder body is unfolded, a plurality of the first gas holes and the second gas holes are rectangularly arranged and have equal spacing, the spacing between any two adjacent groups of the first gas holes is four times the diameter of the first gas hole, and the spacing between any two adjacent groups of the second gas holes is four times the diameter of the second gas hole.

[0015] Preferably, the wind cover is composed of a straight section and a circular arc cover arranged at the front end of the straight section, the straight section is fixedly connected to the inner side wall of the first ring groove and located at the rear side of the first air hole, the inner circular arc of the circular arc cover faces the first air hole, and the maximum outer diameter of the circular arc cover is greater than the outer diameter of the outer ring sleeve.

[0016] Preferably, the gas guide structure comprises a first guide ring and a second guide ring, the first guide ring and the second guide ring are arranged in sequence on the inner side wall of the second ring groove in front and back distribution, an annular emission port is formed between the first guide ring and the second guide ring, the annular emission port is communicated with the second air hole, the inner diameter of the first guide ring and the inner diameter of the second guide ring are consistent with the inner diameter of the inner ring sleeve, the first guide ring and the second guide ring are both formed by splicing three semicircular rings, and the material of the first guide ring and the second guide ring is silicon nitride ceramic.

[0017] Preferably, the outer wall of the first guide ring is sequentially provided with a first plane section and a first conical section in front and back distribution, the inner side wall of the second guide ring is sequentially provided with a second conical section and a second plane section in front and back distribution, a transition circular arc is arranged between the second conical section and the second plane section, and the end of the second conical section away from the second plane section is aligned with the rear edge of the end of the second air hole inside the second ring groove.

[0018] Preferably, the included angle between the outer wall of the first conical section and the axis of the cylinder in the side view cross section and the inner side wall of the second conical section and the axis of the cylinder is between four degrees and six degrees.

[0019] Preferably, the annular emission port is arranged between the opposite sides of the first conical section and the second conical section, and the vertical distance between the opposite sides of the first conical section and the second conical section is one fifth to one tenth of the diameter of the second air hole.

[0020] (Three) beneficial effects

[0021] The application provides an improved APU flame tube inner and outer ring cooling device.

[0022] 1. Compared with the prior art, the improved APU flame tube inner and outer ring cooling device is provided with first air holes and second air holes opposite to each other on the outer ring sleeve and the inner ring sleeve, and an annular emission port formed by a first conical section and a second conical section is arranged between the second air hole and the inner side wall of the inner ring sleeve. After the cold air enters the annular channel from the air inlet, part of the cold air flows along the annular channel to the air outlet, part of the cold air enters the first air hole into the impact chamber, and then enters the second air hole from the impact chamber. The cold air is sent into the annular emission port from the second air hole. The cold air flow forms an annular cooling gas film through the annular emission port, and forms a complete protection structure for the inner side wall of the inner cylinder. The temperature difference area of the inner side wall of the cylinder is effectively avoided, so that the thermal stress of the cylinder is not too large, and the cracks, block falling and deformation caused by the thermal stress are avoided.

[0023] 2、Compared with the prior art, the improved APU flame tube inner and outer ring cooling device sets a first ring groove on the outer ring sleeve, and sets a wind collecting cover for intercepting cooling airflow in the first ring groove. A plurality of wind collecting covers can be prepared according to different heights of the wind collecting cover protruding from the surface of the outer ring sleeve, so as to adapt to the needs of different cooling airflow shunt flow. By setting the wind collecting cover, the cooling airflow flow entering the first gas hole can be more accurately controlled, so that the best shunt state is adjusted under the premise of not increasing the cooling airflow flow, that is, the combustion efficiency is not affected, and the best cooling effect is obtained.

[0024] 3、Compared with the prior art, the improved APU flame tube inner and outer ring cooling device sets a transition arc on the inner side wall of the second guide ring, and sets the inclination angles of the first conical section and the second conical section, so that the cooling airflow can be discharged as close as possible to the inner side wall of the cylinder located behind the annular discharge port when the cooling airflow is discharged from the annular discharge port, thereby avoiding being blown away by high-temperature gas and forming an effective annular cooling gas film. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the application;

[0026] Figure 2 It is a partial sectional view of the internal structure of the combustion chamber casing and cylinder;

[0027] Figure 3 It is a partial enlarged view of A in the application; Figure 2

[0028] Figure 4 It is a partial sectional view of the internal structure of the inner ring sleeve;

[0029] Figure 5 It is a schematic diagram of the wind collecting cover structure;

[0030] Figure 6 It is a schematic diagram of the first guide ring structure;

[0031] Figure 7 It is a partial sectional view of the internal structure of the second guide ring;

[0032] ​Wherein, 1, combustion chamber case; 2, air inlet; 3, air outlet; 4, barrel; 401, outer ring cover; 402, support column; 403, inner ring cover; 5, annular channel; 6, support ring; 7, support plate; 8, impact cavity; 9, first ring groove; 10, first air hole; 11, wind collecting cover; 1101, straight section; 1102, circular arc cover; 12, second air hole; 13, first guide ring; 1301, first plane section; 1302, first conical surface section; 14, second guide ring; 1401, second conical surface section; 1402, transition circular arc; 1403, second plane section; 15, annular emission port; 16, second ring groove. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0034] Embodiment one:

[0035] As Figures 1 to 7As shown, the embodiment of the present application provides an improved APU flame tube inner and outer ring cooling device, comprising a combustion chamber case 1, a cylinder body 4, the combustion chamber case 1 is provided with an air inlet 2 and an air outlet 3 at the front and rear ends respectively, the cylinder body 4 is arranged inside the combustion chamber case 1, the cylinder body 4 and the combustion chamber case 1 are fixedly connected through a plurality of front and rear distributed support rings 6, an annular channel 5 is formed between the cylinder body 4 and the combustion chamber case 1, the plurality of support rings 6 are each composed of an inner ring plate, an outer ring plate and a plurality of support plates 7 arranged between the inner ring plate and the outer ring plate, the outer wall of the outer ring plate of the support ring 6 is fixedly connected with the inner side wall of the combustion chamber case 1, the outer wall of the cylinder body 4 is fixedly connected with the inner side wall of the inner ring plate of the support ring 6, the plurality of support plates 7 are circumferentially divided and distributed with the axis of the support ring 6 as the center, the cylinder body 4 is composed of an outer ring sleeve 401 and an inner ring sleeve 403 arranged concentrically, the outer ring sleeve 401 and the inner ring sleeve 403 are fixedly connected through a plurality of support columns 402, an impact cavity 8 is formed between the outer ring sleeve 401 and the inner ring sleeve 403, a plurality of first gas holes 10 penetrating in and out are arranged on the outer wall of the outer ring sleeve 401, a plurality of second gas holes 12 penetrating in and out are arranged on the outer wall of the inner ring sleeve 403, a wind collector 11 for guiding part of the gas in the annular channel 5 into the first gas holes 10 and the impact cavity 8 is arranged on the outer wall of the outer ring sleeve 401, a gas guiding structure for guiding the gas towards the inner side wall of the inner ring sleeve 403 when the gas in the impact cavity 8 enters the inner side wall of the inner ring sleeve 403 from the second gas holes 12 is arranged on the inner side wall of the inner ring sleeve 403, the support ring 6 is used for supporting and fixing the combustion chamber case 1 and the cylinder body 4, after the inner ring plate and the outer ring plate of the support ring 6 are supported by the plurality of support plates 7, a larger flow space is formed, and the flow resistance caused by the fixing structure of the combustion chamber case 1 and the cylinder body 4 to the cooling gas flow is minimized;

[0036] In order to cool and protect the inner wall of the cylinder 4, the first gas holes 10 and the second gas holes 12 partially overlap after the cylinder 4 is expanded. The first gas holes 10 and the second gas holes 12 are inclined holes, and the axes of the corresponding first gas holes 10 and second gas holes 12 are opposite. The angle between the axis extension line of the first gas holes 10 and the second gas holes 12 and the axis line of the cylinder 4 is 35 degrees. The diameters of the first gas holes 10 and the second gas holes 12 are equal. The diameter of the first gas hole 10 is 3 / 5 of the width of the first ring groove 9, and the diameter of the second gas hole 12 is 3 / 5 of the width of the second ring groove 16. When the cylinder 4 is expanded, the first gas holes 10 and the second gas holes 12 are arranged in a rectangular array with equal spacing. The spacing between any two adjacent groups of first gas holes 10 is four times the diameter of the first gas hole 10, and the spacing between any two adjacent groups of second gas holes 12 is four times the diameter of the second gas hole 12. The opposite first gas holes 10 and second gas holes 12 allow the cooling gas flow to flow smoothly. By controlling the spacing between the first gas holes 10 and the second gas holes 12 and the diameter of the first gas holes 10 and the second gas holes 12, it can be effectively guaranteed that the cooling gas flow blown out of the annular discharge port 15 can cover the spacing, achieving the purpose of full coverage protection.

[0037] In order to accurately distribute the cooling gas flow in the annular channel 5, the outer wall of the outer ring 401 is provided with a first ring groove 9, and the first gas hole 10 is arranged in the inner wall of the first ring groove 9. The first ring groove 9 is connected to the inside of the impact chamber 8 through the first gas hole 10. The wind collecting cover 11 is arranged on the inner wall of the first ring groove 9 and located behind the first gas hole 10. The wind collecting cover 11 is composed of a straight section 1101 and a circular arc cover 1102 arranged at the front end of the straight section 1101. The straight section 1101 is fixedly connected to the inner wall of the first ring groove 9 and located behind the first gas hole 10. The inner circular arc of the circular arc cover 1102 faces the first gas hole 10, and the maximum outer diameter of the circular arc cover 1102 is greater than the outer diameter of the outer ring 401. By arranging the first ring groove 9, the wind collecting cover 11 can be installed in the first ring groove 9, thereby reducing the height of the wind collecting cover 11 protruding from the surface of the outer ring 401, avoiding causing large resistance to the cooling gas flow in the annular channel 5, and controlling the flow of the cooling gas flow distributed to the first gas hole 10 by controlling the height of the circular arc cover 1102 of the wind collecting cover 11 protruding from the outer ring 401;

[0038] In order to form a complete annular cooling air flow on the inner side wall of the inner ring sleeve 403, the inner side wall of the inner ring sleeve 403 is provided with a second ring groove 16, the second gas hole 12 is arranged inside the second ring groove 16, the second ring groove 16 is communicated with the inside of the impingement chamber 8 through the second gas hole 12, and a gas guide structure is arranged on the inner side wall of the second ring groove 16. The gas guide structure includes a first guide ring 13 and a second guide ring 14, which are arranged in sequence on the inner side wall of the second ring groove 16 in front and back. The annular diffusion port 15 is formed between the first guide ring 13 and the second guide ring 14, and the annular diffusion port 15 is communicated with the second gas hole 12. The inner diameter of the first guide ring 13 and the inner diameter of the second guide ring 14 are consistent with the inner diameter of the inner ring sleeve 403. The first guide ring 13 and the second guide ring 14 are both composed of three semicircular rings. The material of the first guide ring 13 and the second guide ring 14 is silicon nitride ceramic. The outer wall of the first guide ring 13 is provided with a first flat section 1301 and a first tapered section 1302 in front and back. The inner side wall of the second guide ring 14 is provided with a second tapered section 1401 and a second flat section 1403 in front and back. The second tapered section 1401 and the second flat section 1403 are provided with a transition arc 1402. The end of the second tapered section 1401 away from the second flat section 1403 is aligned with the rear edge of the end of the second gas hole 12 inside the second ring groove 16. The angle between the outer wall of the first tapered section 1302 and the axis of the cylinder 4 and the inner side wall of the second tapered section 1401 and the axis of the cylinder 4 is four degrees. The annular diffusion port 15 is arranged between the opposite side of the first tapered section 1302 and the second tapered section 1401. The vertical distance between the opposite side of the first tapered section 1302 and the second tapered section 1401 is one tenth of the diameter of the second gas hole 12. The cooling air flow enters the annular diffusion port 15 from the impingement chamber 8 through the second gas hole 12, and forms an annular cooling air film through the annular diffusion port 15, which protects between the high-temperature gas and the inner side wall of the cylinder 4, thereby forming a better protection effect. The four-degree angle between the outer wall of the first tapered section 1302 and the axis of the cylinder 4 and the inner side wall of the second tapered section 1401 and the axis of the cylinder 4, combined with the vertical distance between the opposite side of the first tapered section 1302 and the second tapered section 1401 being one tenth of the diameter of the second gas hole 12, makes the blown cooling air film thin but with large air flow pressure, which is not easy to be blown away.

[0039] Example two

[0040] In order to form a complete annular cooling air flow on the inner side wall of the inner ring sleeve 403, the inner side wall of the inner ring sleeve 403 is provided with a second ring groove 16, the second gas hole 12 is arranged inside the second ring groove 16, the second ring groove 16 is communicated with the inside of the impingement cavity 8 through the second gas hole 12, and a gas guide structure is arranged on the inner side wall of the second ring groove 16. The gas guide structure includes a first guide ring 13 and a second guide ring 14, which are arranged in sequence on the inner side wall of the second ring groove 16 in front and back. The annular diffusion port 15 is formed between the first guide ring 13 and the second guide ring 14, and the annular diffusion port 15 is communicated with the second gas hole 12. The inner diameter of the first guide ring 13 and the inner diameter of the second guide ring 14 are consistent with the inner diameter of the inner ring sleeve 403. The first guide ring 13 and the second guide ring 14 are both composed of three semicircular rings. The material of the first guide ring 13 and the second guide ring 14 is silicon nitride ceramic. The outer wall of the first guide ring 13 is provided with a first flat section 1301 and a first tapered section 1302 in front and back. The inner side wall of the second guide ring 14 is provided with a second tapered section 1401 and a second flat section 1403 in front and back. The second tapered section 1401 and the second flat section 1403 are provided with a transition arc 1402. The end of the second tapered section 1401 away from the second flat section 1403 is aligned with the rear edge of the end of the second gas hole 12 inside the second ring groove 16. The angle between the outer wall of the first tapered section 1302 and the axis of the cylinder 4 and the inner side wall of the second tapered section 1401 and the axis of the cylinder 4 is six degrees. The annular diffusion port 15 is arranged between the opposite side of the first tapered section 1302 and the second tapered section 1401. The vertical distance between the opposite side of the first tapered section 1302 and the second tapered section 1401 is one fifth of the diameter of the second gas hole 12. The cooling air flow enters the annular diffusion port 15 from the impingement cavity 8 through the second gas hole 12, and forms an annular cooling air film through the annular diffusion port 15, which protects between the high-temperature gas and the inner side wall of the cylinder 4, thereby forming a better protection effect. The difference between this embodiment and the first embodiment is that there is a six-degree angle between the outer wall of the first tapered section 1302 and the axis of the cylinder 4 and the inner side wall of the second tapered section 1401 and the axis of the cylinder 4, and the vertical distance between the opposite side of the first tapered section 1302 and the second tapered section 1401 is one fifth of the diameter of the second gas hole 12, so that the blown cooling air film is thicker than the air flow generated in the first embodiment, and the cooling effect is better, but the amount of cooling air flow is larger than that in the first embodiment. The cooling requirement can be flexibly selected according to the cooling requirement.

[0041] Working principle: the support ring 6 is used for supporting and fixing the combustion chamber casing 1 and the cylinder 4, after the inner ring plate and the outer ring plate of the support ring 6 are supported through a plurality of support plates 7, a larger flow space is formed, the flow resistance caused by the fixing structure of the combustion chamber casing 1 and the cylinder 4 to the cooling airflow is reduced as much as possible, the first air hole 10 and the second air hole 12 opposite to each other enable the cooling airflow to flow smoothly, by restricting the relationship between the interval between the first air hole 10 and the second air hole 12 adjacent to each other and the aperture of the first air hole 10 and the second air hole 12, it can be effectively guaranteed that the cooling airflow blown out from the annular emission port 15 can cover the interval, so as to achieve the purpose of full coverage protection, by setting the first ring groove 9, the wind concentrator 11 can be installed in the first ring groove 9, so as to reduce the height of the wind concentrator 11 protruding from the surface of the outer ring sleeve 401, avoiding causing great resistance to the cooling airflow in the annular channel 5, by controlling the height of the circular arc finder 1102 of the wind concentrator 11 protruding from the outer ring sleeve 401, the cooling airflow flow rate shunted into the first air hole 10 can be controlled, the four-degree included angle between the outer wall of the first conical section 1302 and the axis of the cylinder 4 and the inner side wall of the second conical section 1401 and the axis of the cylinder 4, combined with the vertical distance between the opposite sides of the first conical section 1302 and the second conical section 1401 being one tenth of the aperture of the second air hole 12, makes the blown cooling air film have the effect of being thin but having large airflow pressure and not being easy to be blown away, when the included angle between the outer wall of the first conical section 1302 and the axis of the cylinder 4 and the inner side wall of the second conical section 1401 and the axis of the cylinder 4 is six degrees, the vertical distance between the opposite sides of the first conical section 1302 and the second conical section 1401 is one fifth of the aperture of the second air hole 12, so that the blown cooling air film is thicker than the airflow generated in embodiment one, and the cooling effect is better, but the cooling airflow consumption is larger than that in embodiment one, and the cooling requirement can be flexibly selected according to the cooling requirement.

[0042] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. An improved cooling device for the inner and outer rings of an APU flame tube, characterized in that: The combustion chamber housing includes a combustion chamber casing (1) and a cylindrical body (4). The combustion chamber casing (1) has an air inlet (2) and an air outlet (3) at its front and rear ends, respectively. The cylindrical body (4) is located inside the combustion chamber casing (1). The cylindrical body (4) and the combustion chamber casing (1) are fixedly connected by multiple sets of support rings (6) arranged in a front-to-back pattern. An annular channel (5) is formed between the cylindrical body (4) and the combustion chamber casing (1). Each set of support rings (6) consists of an inner ring plate, an outer ring plate, and multiple sets of support plates (7) arranged concentrically. The outer wall of the outer ring plate of the support ring (6) is fixedly connected to the inner wall of the combustion chamber casing (1). The outer wall of the cylindrical body (4) is fixedly connected to the inner wall of the inner ring plate of the support ring (6). Each set of support plates (7) is evenly distributed in a circle with the axis of the support ring (6) as the center. The cylindrical body (4) consists of multiple sets of support rings (6) arranged in a front-to-back pattern. The device consists of an outer ring (401) and an inner ring (403) with a central setting. The outer ring (401) and the inner ring (403) are fixedly connected by multiple sets of support columns (402). An impact chamber (8) is formed between the outer ring (401) and the inner ring (403). The outer wall of the outer ring (401) is provided with multiple sets of first air holes (10) that are connected inside and outside. The outer wall of the inner ring (403) is provided with multiple sets of second air holes (12) that are connected inside and outside. The outer wall of the outer ring (401) is provided with a wind-gathering hood (11) for introducing part of the gas in the annular channel (5) into the first air holes (10) and the impact chamber (8). The inner wall of the inner ring (403) is provided with a gas guiding structure for guiding the gas in the impact chamber (8) towards the inner wall of the inner ring (403) when the gas enters the inner wall of the inner ring (403) from the second air holes (12).

2. The improved APU flame tube inner and outer ring cooling device according to claim 1, characterized in that: The outer ring sleeve (401) has a first ring groove (9) on its outer wall, and the first air hole (10) is located on the inner side wall of the first ring groove (9). The first ring groove (9) communicates with the inside of the impact chamber (8) through the first air hole (10). The wind shroud (11) is located on the inner side wall of the first ring groove (9) and is located behind the first air hole (10).

3. The improved APU flame tube inner and outer ring cooling device according to claim 2, characterized in that: The inner ring sleeve (403) has a second annular groove (16) on its inner sidewall. The second air hole (12) is located inside the second annular groove (16). The second annular groove (16) communicates with the inside of the impact chamber (8) through the second air hole (12). The air guiding structure is located on the inner sidewall of the second annular groove (16).

4. The improved APU flame tube inner and outer ring cooling device according to claim 3, characterized in that: After the cylinder (4) is unfolded, the first air holes (10) of the multiple sets of the first air holes (10) partially overlap with one of the second air holes (12) of the multiple sets of the second air holes (12). The first air holes (10) and the second air holes (12) are both oblique holes and the axes of the corresponding first air holes (10) and second air holes (12) are opposite each other. The angle between the extended lines of the axes of the first air holes (10) and the second air holes (12) and the axis of the cylinder (4) is 35 degrees. The diameters of the first air holes (10) and the second air holes (12) are equal. The diameter of the first air hole (10) is three-fifths of the width of the first annular groove (9), and the diameter of the second air hole (12) is three-fifths of the width of the second annular groove (16).

5. The improved APU flame tube inner and outer ring cooling device according to claim 4, characterized in that: When the cylinder (4) is unfolded, multiple sets of first air holes (10) and second air holes (12) are arranged in a rectangular array with equal spacing. The spacing between any two adjacent sets of the first air holes (10) is four times the diameter of the first air hole (10), and the spacing between any two adjacent sets of the second air holes (12) is four times the diameter of the second air hole (12).

6. The improved APU flame tube inner and outer ring cooling device according to claim 5, characterized in that: The wind-gathering cover (11) consists of a straight section (1101) and an arc cover (1102) located at the front end of the straight section (1101). The straight section (1101) is fixedly connected to the inner wall of the first ring groove (9) and located behind the first air hole (10). The inner arc of the arc cover (1102) faces the first air hole (10) and the maximum outer diameter of the arc cover (1102) is greater than the outer diameter of the outer ring sleeve (401).

7. The improved APU flame tube inner and outer ring cooling device according to claim 6, characterized in that: The air guiding structure includes a first guide ring (13) and a second guide ring (14). The first guide ring (13) and the second guide ring (14) are arranged sequentially in front and behind on the inner sidewall of the second ring groove (16). An annular vent (15) is formed between the first guide ring (13) and the second guide ring (14). The annular vent (15) communicates with the second air hole (12). The inner diameter of the first guide ring (13) and the inner diameter of the second guide ring (14) are the same as the inner diameter of the inner ring sleeve (403). The first guide ring (13) and the second guide ring (14) are both made of three semi-circular rings spliced ​​together. The first guide ring (13) and the second guide ring (14) are both made of silicon nitride ceramic.

8. The improved APU flame tube inner and outer ring cooling device according to claim 7, characterized in that: The outer wall of the first guide ring (13) is provided with a first planar section (1301) and a first conical section (1302) arranged in a front-to-back manner. The inner wall of the second guide ring (14) is provided with a second conical section (1401) and a second planar section (1403) arranged in a front-to-back manner. A transition arc (1402) is provided between the second conical section (1401) and the second planar section (1403). The end of the second conical section (1401) away from the second planar section (1403) is aligned with the rear edge of the end of the second air hole (12) located inside the second ring groove (16).

9. The improved APU flame tube inner and outer ring cooling device according to claim 8, characterized in that: The angle between the outer wall of the first conical section (1302) and the axis of the cylinder (4) and the inner wall of the second conical section (1401) and the axis of the cylinder (4) in the side view section is between four and six degrees.

10. The improved APU flame tube inner and outer ring cooling device according to claim 9, characterized in that: The annular vent (15) is located between the first conical section (1302) and the second conical section (1401) on opposite sides, and the vertical distance between the first conical section (1302) and the second conical section (1401) on opposite sides is one-fifth to one-tenth of the diameter of the second vent (12).

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