Cooling device for improving inner ring and outer ring of APU flame tube

Abstract

The invention provides a cooling device for improving inner and outer rings of an APU flame tube, and relates to the technical field of aero-engines. The improved cooling device for the inner ring and the outer ring of the APU flame tube comprises a combustion chamber casing and a tube body. Cooling airflow forms an annular cooling air film through an annular emission opening, a complete protection structure is formed on the inner side wall of the inner cylinder, and an obvious temperature difference area is effectively prevented from being formed on the inner side wall of the cylinder body, so that faults such as cracks, chipping and deformation caused by overlarge thermal stress of the cylinder body are avoided; by arranging a transition arc on the inner side wall of a second guide ring and arranging inclined angles of a first conical surface section and a second conical surface section, the cooling air flow can be close to the inner side wall of the cylinder body behind an annular emission opening as much as possible when being discharged from the annular emission opening, and the cooling air flow can be more accurately controlled. And blowing away by high-temperature fuel gas is avoided, and an effective annular cooling gas film is formed.

Description

Technical Field

[0001] The present invention relates to the technical field of aviation engines, and in particular to a device for improving the cooling of inner and outer rings of an APU flame tube. Background Art

[0002] With the improvement of the thrust-to-weight ratio of aviation gas turbine engines, combustion chamber design is developing towards high temperature rise and high heat capacity. The combustion temperature in the combustion chamber of modern aircraft engines can reach over 2000 degrees Celsius and the pressure can reach up to 30 atmospheres. As the place where combustion is organized, the flame tube works in a high temperature and high pressure environment for a long time, and is subject to great thermal stress, creep stress and fatigue stress. Therefore, the life and reliability of the flame tube become one of the key components that determine the life and reliability of the engine. The flame tube is generally made of high-temperature resistant alloys, but the current temperature resistance of metal materials is below 1000 degrees Celsius, which is far lower than the gas temperature. Moreover, the temperature resistance of metal materials has increased much slower than the gas temperature in recent decades. Therefore, relying solely on materials for thermal protection is far from meeting the requirements, and effective cooling of the flame tube is imperative.

[0003] Currently, the commonly used cooling technologies for the flame tube wall are mainly convection cooling (including impingement cooling) and film cooling. However, in high thrust-to-weight ratio engines, the enhanced cooling of the high temperature rise and high heat capacity combustion chamber wall faces a very prominent contradiction: on the one hand, the increase in the combustion chamber temperature increases the amount of air involved in combustion, resulting in a decrease in the amount of air used for cooling; on the other hand, the increase in compressor outlet temperature increases the temperature of the air used to cool the flame tube wall, resulting in a decrease in cooling potential, thus placing higher requirements on the flame tube wall cooling technology. Improving the cooling efficiency of the cooling air is particularly important and urgently needs to be solved. This problem must be solved by adopting innovative technologies.

[0004] In addition, the factors that have a greater impact on the life of the flame tube mainly come from the size of the thermal stress. Therefore, when implementing cooling technology, it is necessary not only to consider reducing the temperature of the flame tube wall, but also to reduce the temperature gradient of the flame tube wall to prevent excessive thermal stress in the flame tube due to excessive temperature gradient, thereby causing cracks, falling blocks, deformation and other faults in the flame tube. In order to further improve the wall cooling effect of the combustion chamber flame tube, researchers at home and abroad have developed a variety of cooling methods. These cooling technologies have undoubtedly brought about improvements in the cooling effect, but a common problem of these cooling structures is that the consumption of cold air is too large, and the overall temperature distribution of the flame tube is not uniform, resulting in large thermal stress. Therefore, how to carefully tap the cooling capacity of the cold air and reduce the thermal stress of the flame tube plate has become a challenge facing existing technologies;

[0005] To this end, there is a publicly available technology on the market that proposes a cooling structure for the flame tube of an aircraft engine combustion chamber, including a flame tube wall panel, wherein the flame tube wall panel includes an outer wall panel and an inner wall panel, and a plurality of diverging holes are provided on the inner wall panel, while a plurality of impact holes are provided on the outer wall panel, and each diverging hole and impact hole are distributed in a cross-row manner, and the inner wall panel and the outer wall panel are connected by a plurality of interference flow columns; the flame tube wall panel is axially divided into two parts, namely, a front section flame tube wall panel close to the high-temperature area of the combustion chamber, and a rear section flame tube wall panel away from the high-temperature area of the combustion chamber; the aperture of the front section impact hole on the front section flame tube wall panel is larger than the aperture of the rear section impact hole on the rear section flame tube wall panel, and the aperture of the front section diverging hole on the front section flame tube wall panel is larger than the aperture of the rear section diverging hole on the rear section flame tube wall panel. Therefore, the present invention improves the traditional flame tube wall cooling structure, fully taps its cooling potential without increasing the amount of cold air, improves cooling efficiency, and avoids excessive thermal stress caused by excessively high flame tube wall temperature and uneven distribution;

[0006] The above-mentioned disclosed technology divides the flame tube cooling part into front and rear sections, and changes the cooling effect through different impact hole diameters in the front and rear sections to solve the problem of uneven temperature distribution on the flame tube wall. In fact, when the airflow enters the flame tube through the impact hole and is carried by the high-temperature combustion gas, it is difficult to form a uniform cooling air film on the inner wall of the flame tube, that is, it is impossible to completely cover the inner wall of the flame tube. As a result, a more obvious temperature difference area is formed on the inner wall of the flame tube under long-term use, resulting in excessive thermal stress in the flame tube, thereby causing cracks, falling blocks, deformation and other faults in the flame tube. Therefore, it is necessary to optimize and improve the structure of the flame tube cooling device. Summary of the Invention

[0007] (1) Technical problems solved

[0008] In response to the shortcomings of the existing technology, the present invention provides an improved cooling device for the inner and outer rings of the APU flame tube, which solves the problem in the existing technology that the cooling air film on the inner wall of the flame tube cannot completely cover the inner wall of the flame tube. As a result, a relatively obvious temperature difference area is formed on the inner wall of the flame tube after long-term use, resulting in excessive thermal stress in the flame tube, which may cause cracks, falling pieces, deformation and other faults in the flame tube.

[0009] (2) Technical solution

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions: an improved APU flame tube inner and outer ring cooling device, comprising a combustion chamber casing and a cylinder, wherein the front and rear ends of the combustion chamber casing are respectively provided with an air inlet and an air outlet, the cylinder is arranged inside the combustion chamber casing, the cylinder and the combustion chamber casing are fixedly connected by multiple groups of support rings distributed front and back, an annular channel is formed between the cylinder and the combustion chamber casing, the multiple groups of support rings are composed of concentrically arranged inner ring plates, outer ring plates and multiple groups of support plates arranged between the inner ring plates and the outer ring plates, the outer wall of the outer ring plate of the support ring is fixedly connected to the inner side wall of the combustion chamber casing, the outer wall of the cylinder is connected to the inner wall of the inner ring plate of the support ring The support plates are fixedly connected, and the multiple groups of support plates are equally distributed in a circle with the axis of the support ring as the center. The cylinder is composed of an outer ring sleeve and an inner ring sleeve which are concentrically arranged. The outer ring sleeve and the inner ring sleeve are fixedly connected by multiple groups 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 multiple groups of first air holes which are through-connected inside and outside, and the outer wall of the inner ring sleeve is provided with multiple groups of second air holes which are through-connected inside and outside. The outer wall of the outer ring sleeve is provided with a wind collecting hood for introducing part of the gas in the annular channel into the first air holes and the inside of the impact cavity, and the inner side wall of the inner ring sleeve is provided with an air guide structure for guiding the gas in the impact cavity toward the inner side wall of the inner ring sleeve when the gas enters the inner side wall of the inner ring sleeve from the second air holes.

[0011] Preferably, the outer wall of the outer ring sleeve is provided with a first annular groove, the first air hole is provided on the inner wall of the first annular groove, the first annular groove is connected with the inside of the impact cavity through the first air hole, and the wind collecting cover is provided on the inner wall of the first annular groove and is located behind the first air hole.

[0012] Preferably, the inner side wall of the inner ring sleeve is provided with a second annular groove, the second air hole is provided inside the second annular groove, the second annular groove is connected with the inside of the impact cavity through the second air hole, and the air guide structure is provided on the inner side wall of the second annular groove.

[0013] Preferably, after the cylinder is unfolded, the multiple groups of first air holes partially overlap with one group of the multiple groups of second air holes respectively, the first air holes and the second air holes are both inclined holes, and the axes of the first air holes and the second air holes corresponding to the inside and outside are relative, the angle between the extension line of the axis of the first air hole and the second air hole and the axis of the cylinder is thirty-five degrees, the apertures of the first air hole and the second air hole are equal, the diameter of the first air hole is three-fifths of the width of the first annular groove, and the diameter of the second air hole is three-fifths of the width of the second annular groove.

[0014] Preferably, when the cylinder is expanded, the multiple groups of first air holes and second air holes are arranged in a rectangular shape with equal spacing. The spacing between any two adjacent groups in the multiple groups of first air holes is four times the diameter of the first air holes, and the spacing between any two adjacent groups in the multiple groups of second air holes is four times the diameter of the second air holes.

[0015] Preferably, the wind gathering hood consists of a straight section and an arc hood arranged at the front end of the straight section. The straight section is fixedly connected to the inner wall of the first ring groove and is located behind the first air hole. The inner arc of the arc hood faces the first air hole and the maximum outer diameter of the arc hood is larger than the outer diameter of the outer ring sleeve.

[0016] Preferably, the air guide structure includes a first guide ring and a second guide ring, and the first guide ring and the second guide ring are arranged in sequence on the inner side wall of the second ring groove in a front-to-back distribution. An annular emission port is formed between the first guide ring and the second guide ring, and the annular emission port is connected 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 made of three semicircular rings, and the first guide ring and the second guide ring are both made of silicon nitride ceramics.

[0017] Preferably, the outer wall of the first guide ring is provided with a first plane section and a first conical section in sequence in a front-to-back distribution, and the inner wall of the second guide ring is provided with a second conical section and a second plane section in sequence in a front-to-back distribution, a transition arc is provided 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 one end of the second air hole located inside the second ring groove.

[0018] Preferably, the angles between the outer wall of the first conical section and the axis of the cylinder, and between the inner wall of the second conical section and the axis of the cylinder in a side view section are between four and six degrees.

[0019] Preferably, the annular emission port is arranged between the first conical segment and the opposite side of the second conical segment, and the vertical distance between the first conical segment and the opposite side of the second conical segment is one fifth to one tenth of the aperture of the second pore.

[0020] (3) Beneficial effects

[0021] The present invention provides a device for improving the cooling of the inner and outer rings of the APU flame tube. It has the following beneficial effects:

[0022] 1. Compared with the existing technology, this improved APU flame tube inner and outer ring cooling device is provided with first and second air holes, which are opposite to each other, on the outer ring sleeve and the inner ring sleeve respectively. An annular dispensing port formed by a first conical surface segment and a second conical surface segment is provided 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 it flows along the annular channel toward the air outlet, and part of it enters the first air hole and enters the impact cavity, and then enters the second air hole from the impact cavity, and is sent to the annular dispensing port through the second air hole. The cooling airflow forms an annular cooling air film through the annular dispensing port, forming a complete protective structure for the inner side wall of the inner tube, effectively avoiding the formation of a relatively obvious temperature difference area on the inner side wall of the tube, thereby avoiding cracks, falling blocks, deformation and other failures caused by excessive thermal stress of the tube.

[0023] 2. Compared with the existing technology, this improved APU flame tube inner and outer ring cooling device provides a first annular groove on the outer ring sleeve, and a wind collecting hood for intercepting the cooling airflow is provided in the first annular groove. Multiple wind collecting hoods can be prepared according to the height of the wind collecting hood protruding from the surface of the outer ring sleeve to meet the requirements of different cooling airflow diversion flow rates. By providing the wind collecting hood, the cooling airflow flow entering the first air hole can be more accurately controlled, thereby adjusting to the optimal diversion state without increasing the cooling airflow flow rate, that is, it does not affect the combustion efficiency and can achieve the best cooling effect.

[0024] 3. Compared with the existing technology, this improved APU flame tube inner and outer ring cooling device, by setting a transition arc on the inner side wall of the second guide ring and setting the inclination angles of the first and second conical segments, allows the cooling airflow to be discharged from the annular emission port as close as possible to the inner side wall of the cylinder located behind the annular emission port, avoiding being blown away by the high-temperature combustion gas, and forming an effective annular cooling air film. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0027] Figure 3 For the present invention Figure 2 A partial enlarged view of point A in the middle;

[0028] Figure 4 A partial side cross-sectional view of the internal structure of the inner ring sleeve of the present invention;

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

[0030] Figure 6 This is a schematic structural diagram of the first guide ring of the present invention;

[0031] Figure 7 It is a partial sectional view of the side of the internal structure of the second guide ring of the present invention.

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

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] Example 1:

[0035] like Figures 1 to 7As shown, an embodiment of the present invention provides an improved inner and outer ring cooling device for an APU flame tube, comprising a combustion chamber casing 1 and a cylinder 4. An air inlet 2 and an air outlet 3 are respectively provided at the front and rear ends of the combustion chamber casing 1. The cylinder 4 is arranged inside the combustion chamber casing 1. The cylinder 4 and the combustion chamber casing 1 are fixedly connected by multiple groups of support rings 6 distributed front and back. An annular channel 5 is formed between the cylinder 4 and the combustion chamber casing 1. The multiple groups of support rings 6 are composed of concentrically arranged inner ring plates, outer ring plates and multiple groups of support plates 7 arranged between the inner ring plates and the outer ring plates. The outer wall of the outer ring plate of the support ring 6 is fixedly connected to the inner side wall of the combustion chamber casing 1. The outer wall of the cylinder 4 is fixedly connected to the inner side wall of the inner ring plate of the support ring 6. The multiple groups of support plates 7 are equally distributed on the circumference with the axis of the support ring 6 as the center. The cylinder 4 is composed of concentrically arranged outer ring sleeves 401 and inner ring sleeves 403. The two are fixedly connected by multiple groups of support columns 402, and an impact cavity 8 is formed between the outer ring sleeve 401 and the inner ring sleeve 403. The outer wall of the outer ring sleeve 401 is provided with multiple groups of first air holes 10 that are connected inside and outside, and the outer wall of the inner ring sleeve 403 is provided with multiple groups of second air holes 12 that are connected inside and outside. The outer wall of the outer ring sleeve 401 is provided with a wind collecting cover 11 for introducing part of the gas in the annular channel 5 into the first air holes 10 and the impact cavity 8. The inner side wall of the inner ring sleeve 403 is provided with an air guide structure for guiding the gas in the impact cavity 8 toward the inner side wall of the inner ring sleeve 403 when the gas enters the inner side wall of the inner ring sleeve 403 from the second air holes 12. The support ring 6 is used to support and fix 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 by multiple groups of support plates 7, a larger flow space is formed, which minimizes the flow resistance of the fixed structure of the combustion chamber casing 1 and the cylinder 4 to the cooling airflow;

[0036] In order to cool and protect the inner wall of the cylinder 4, after the cylinder 4 is unfolded, the multiple groups of first air holes 10 are respectively overlapped with one of the multiple groups of second air holes 12. The first air holes 10 and the second air holes 12 are both inclined holes and the axes of the first air holes 10 and the second air holes 12 corresponding to the inside and outside are relative. 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 thirty-five degrees. The apertures 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. When the cylinder 4 is unfolded, the multiple groups of first air holes 10 The second air holes 12 are all arranged in a rectangular shape and have equal spacing. The spacing between any two adjacent groups in the front and back of the multiple groups of first air holes 10 is four times the diameter of the first air holes 10. The spacing between any two adjacent groups in the front and back of the multiple groups of second air holes 12 is four times the diameter of the second air holes 12. The first air holes 10 and the second air holes 12 facing each other allow the cooling air flow to flow smoothly. By constraining the relationship between the spacing between the adjacent first air holes 10 and the second air holes 12 and the apertures of the first air holes 10 and the second air holes 12, it can be effectively ensured that the cooling air flow blown out from the annular emission port 15 can cover the spacing, thereby achieving the purpose of full coverage protection.

[0037] In order to accurately divert the cooling airflow in the annular channel 5, a first annular groove 9 is provided on the outer wall of the outer ring sleeve 401, and a first air hole 10 is provided on the inner wall of the first annular groove 9. The first annular groove 9 is connected to the inside of the impact cavity 8 through the first air hole 10. A wind collecting cover 11 is provided on the inner wall of the first annular groove 9 and is located behind the first air hole 10. The wind collecting cover 11 is composed of a straight section 1101 and an arc cover 1102 provided at the front end of the straight section 1101. The straight section 1101 is fixedly connected to the inner wall of the first annular groove 9 and is located at the first air hole On the rear side of 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. By providing the first annular groove 9, the wind collecting cover 11 can be installed in the first annular groove 9, thereby reducing the height of the wind collecting cover 11 protruding from the surface of the outer ring sleeve 401, avoiding causing greater resistance to the cooling airflow in the annular channel 5. By controlling the height of the arc 1102 of the wind collecting cover 11 protruding from the outer ring sleeve 401, the flow rate of the cooling airflow diverted to the first air hole 10 can be controlled;

[0038] In order to form a complete annular cooling airflow on the inner wall of the inner ring sleeve 403, a second annular groove 16 is provided on the inner wall of the inner ring sleeve 403, and a second air hole 12 is provided inside the second annular groove 16. The second annular groove 16 is connected with the inside of the impact cavity 8 through the second air hole 12. The air guide structure is provided on the inner wall of the second annular groove 16. The air guide 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 in sequence on the inner wall of the second annular groove 16 in a front-to-back distribution. An annular dispensing port 15 is formed between the first guide ring 13 and the second guide ring 14. The annular dispensing port 15 is connected to the inner wall of the second annular groove 16. The second air hole 12 is through, 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 made of three semicircular rings, the first guide ring 13 and the second guide ring 14 are made of silicon nitride ceramics, the outer wall of the first guide ring 13 is sequentially provided with a first plane section 1301 and a first conical section 1302 in a front-to-back distribution, the inner wall of the second guide ring 14 is sequentially provided with a second conical section 1401 and a second plane section 1403 in a front-to-back distribution, and a The transition arc 1402, the end of the second conical section 1401 away from the second plane section 1403 is aligned with the rear edge of the end of the second air hole 12 located inside the second annular groove 16. The angle between the outer wall of the first conical section 1302 and the axis of the cylinder 4, and the angle between the inner wall of the second conical section 1401 and the axis of the cylinder 4 in the side view of the cylinder 4 is four degrees. The annular emission port 15 is arranged between the opposite sides of the first conical section 1302 and the second conical section 1401. The vertical distance between the opposite sides of the first conical section 1302 and the second conical section 1401 is one tenth of the aperture of the second air hole 12. The cooling air The air flow enters the annular dispensing port 15 from the impact chamber 8 through the second air hole 12, and forms an annular cooling air film through the annular dispensing port 15, which is protected between the high-temperature combustion gas and the inner wall of the cylinder 4, thereby forming a better protection effect. The four-degree angle between the outer wall of the first conical section 1302 and the axis of the cylinder 4, and the four-degree angle between the inner 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 thin but has a high airflow pressure and is not easily blown away.

[0039] Example 2

[0040] In order to form a complete annular cooling airflow on the inner wall of the inner ring sleeve 403, the inner wall of the inner ring sleeve 403 is provided with a second annular groove 16, and the second air hole 12 is arranged inside the second annular groove 16. The second annular groove 16 is connected with the inside of the impact cavity 8 through the second air hole 12. The air guide structure is arranged on the inner wall of the second annular groove 16. The air guide 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 in sequence on the inner wall of the second annular groove 16 in a front-to-back distribution. An annular dispensing port 15 is formed between the first guide ring 13 and the second guide ring 14. The annular dispensing port 15 is connected 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 consistent with 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 semicircular rings. The first guide ring 13 and the second guide ring 14 are made of silicon nitride ceramics. The outer wall of the first guide ring 13 is sequentially provided with a first plane section 1301 and a first conical section 1302 in a front-to-back distribution. The inner wall of the second guide ring 14 is sequentially provided with a second conical section 1401 and a second plane section 1403 in a front-to-back distribution. A transition arc 1402 is provided between the second conical section 1401 and the second plane section 1403. The second conical section 1401 is away from the first conical section 1301. One end of the second planar section 1403 is aligned with the rear edge of one end of the second air hole 12 located inside the second annular groove 16. The angles 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 of the cylinder 4 are six degrees. The annular dispersing port 15 is arranged between the opposite sides of the first conical section 1302 and the second conical section 1401. 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. The cooling airflow enters the annular dispersing port 15 from the impact chamber 8 through the second air hole 12, and passes through the annular dispersing port 15. The opening 15 forms an annular cooling air film, which protects the high-temperature combustion gas and the inner wall of the cylinder 4, thereby forming a better protection effect. The difference from the first embodiment is that there is an angle of six degrees between the outer wall of the first conical section 1302 and the axis of the cylinder 4, and between the inner wall of the second conical section 1401 and the axis of the cylinder 4. 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 the first embodiment and the cooling effect is better. However, the amount of cooling airflow used is larger than that in the first embodiment, and can be flexibly selected according to the cooling requirements.

[0041] Working principle: The support ring 6 is used to support and fix the combustion chamber casing 1 and the barrel 4. After the inner ring plate and the outer ring plate of the support ring 6 are supported by multiple groups of support plates 7, a larger circulation space is formed, which minimizes the flow resistance of the fixed structure of the combustion chamber casing 1 and the barrel 4 to the cooling airflow. The first air holes 10 and the second air holes 12 relative to each other inside and outside enable the cooling airflow to flow smoothly. By constraining the relationship between the distance between the front and rear adjacent first air holes 10 and the second air holes 12 and the aperture of the first air holes 10 and the second air holes 12, it can effectively ensure that the cooling airflow blown out from the annular emission port 15 can cover the distance, so as to achieve the purpose of full coverage protection. By setting the first annular groove 9, the wind collecting cover 11 can be installed in the first annular groove 9, thereby reducing the height of the wind collecting cover 11 protruding from the surface of the outer ring sleeve 401, avoiding causing greater resistance to the cooling airflow in the annular channel 5, and by controlling the arc of the wind collecting cover 11 to find 1102 protruding from the outer ring The height of the sleeve 401 can control the flow rate of the cooling air flow diverted to the first air hole 10. The four-degree 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, combined with the vertical distance between the opposite sides of the first conical section 1302 and the second conical section 1401 is one-tenth of the aperture of the second air hole 12, makes the blown cooling air film thinner but has a high airflow pressure and is not easily blown away. When there is a six-degree 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, 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 Example 1, and the cooling effect is better, but the amount of cooling airflow used is larger than that in Example 1, and can be flexibly selected according to cooling requirements.

[0042] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An improved APU flame tube inner and outer ring cooling device, characterized by: The invention comprises a combustion chamber casing (1) and a cylinder (4), wherein the combustion chamber casing (1) is provided with an air inlet (2) and an air outlet (3) at the front and rear ends respectively, and the cylinder (4) is arranged inside the combustion chamber casing (1), and the cylinder (4) and the combustion chamber casing (1) are fixedly connected by a plurality of groups of support rings (6) distributed in a front-to-rear manner, and an annular channel (5) is formed between the cylinder (4) and the combustion chamber casing (1), and the plurality of groups of support rings (6) are composed of an inner ring plate and an outer ring plate arranged concentrically, and a plurality of groups 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 to the inner side wall of the combustion chamber casing (1), the outer wall of the cylinder (4) is fixedly connected to the inner side wall of the inner ring plate of the support ring (6), and the plurality of groups of support plates (7) are distributed in equal parts on the circumference with the axis of the support ring (6) as the center, and the cylinder (4) is composed of a plurality of support rings (6) arranged concentrically. The outer ring sleeve (401) and the inner ring sleeve (403) are fixedly connected by multiple groups of support columns (402), and an impact cavity (8) is formed between the outer ring sleeve (401) and the inner ring sleeve (403). The outer wall of the outer ring sleeve (401) is provided with multiple groups of first air holes (10) that are connected inside and outside, and the outer wall of the inner ring sleeve (403) is provided with multiple groups of second air holes (12) that are connected inside and outside. The outer wall of the outer ring sleeve (401) is provided with a wind collecting cover (11) for introducing part of the gas in the annular channel (5) into the first air holes (10) and the inside of the impact cavity (8), and the inner side wall of the inner ring sleeve (403) is provided with an air guide structure for guiding the gas in the impact cavity (8) toward the inner side wall of the inner ring sleeve (403) when the gas enters the inner side wall of the inner ring sleeve (403) from the second air holes (12).

2. The device for improving the inner and outer ring cooling of the APU flame tube according to claim 1, characterized in that: The outer wall of the outer ring sleeve (401) is provided with a first annular groove (9), the first air hole (10) is provided on the inner wall of the first annular groove (9), the first annular groove (9) is connected with the interior of the impact cavity (8) through the first air hole (10), and the wind collecting cover (11) is provided on the inner wall of the first annular groove (9) and is located behind the first air hole (10).

3. The device for improving the cooling of inner and outer rings of an APU flame tube according to claim 2, characterized in that: The inner side wall of the inner ring sleeve (403) is provided with a second annular groove (16), the second air hole (12) is provided inside the second annular groove (16), the second annular groove (16) is connected with the inside of the impact cavity (8) through the second air hole (12), and the air guide structure is provided on the inner side wall of the second annular groove (16).

4. The device for improving the inner and outer ring cooling of an APU flame tube according to claim 3, characterized in that: After the cylinder (4) is unfolded, the plurality of groups of the first air holes (10) partially overlap with one of the plurality of groups 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 first air holes (10) and the second air holes (12) corresponding to the inside and outside are relative to 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 thirty-five degrees. The apertures 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 device for improving the inner and outer ring cooling of the APU flame tube according to claim 4, characterized in that: When the cylinder (4) is unfolded, the plurality of groups of first air holes (10) and second air holes (12) are arranged in a rectangular shape with equal spacing, the spacing between any two adjacent groups in the plurality of first air holes (10) is four times the diameter of the first air holes (10), and the spacing between any two adjacent groups in the plurality of second air holes (12) is four times the diameter of the second air holes (12).

6. The device for improving the inner and outer ring cooling of the APU flame tube according to claim 5, characterized in that: 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 annular groove (9) and is located behind the first air hole (10); the inner arc of the circular arc cover (1102) faces the first air hole (10) and the maximum outer diameter of the circular arc cover (1102) is greater than the outer diameter of the outer ring sleeve (401).

7. The device for improving the inner and outer ring cooling of the APU flame tube according to claim 6, characterized in that: The air guide structure comprises a first guide ring (13) and a second guide ring (14), the first guide ring (13) and the second guide ring (14) being arranged in sequence on the inner side wall of the second ring groove (16) in a front-to-back distribution, an annular dispensing port (15) being formed between the first guide ring (13) and the second guide ring (14), the annular dispensing port (15) being connected to the second air hole (12), the inner diameters of the first guide ring (13) and the second guide ring (14) being consistent with the inner diameter of the inner ring sleeve (403), the first guide ring (13) and the second guide ring (14) being both formed by splicing three semicircular rings, and the first guide ring (13) and the second guide ring (14) being both made of silicon nitride ceramic.

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

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

10. The device for improving the inner and outer ring cooling of an APU flame tube according to claim 9, characterized in that: The annular emission port (15) is arranged between the first conical surface section (1302) and the opposite side of the second conical surface section (1401), and the vertical distance between the opposite side of the first conical surface section (1302) and the second conical surface section (1401) is one fifth to one tenth of the aperture of the second air hole (12).

Images