A can combustor flame tube assembly cooling structure and a gas turbine engine

Abstract

The application discloses a kind of backflow combustion chamber flame tube combination cooling structure and gas turbine engine, backflow combustion chamber flame tube combination cooling structure includes head ring and first Z type gas film ring, two ends of head ring are respectively equipped with flame tube inner ring and flame tube outer ring, the end of flame tube outer ring away from head ring is provided with big elbow pipe, the end of flame tube inner ring away from head ring is provided with small elbow pipe, first Z type gas film ring includes first part, second part and third part connected in Z type in order, first part is connected with flame tube outer ring, third part is connected with big elbow pipe, first cooling hole is provided along the thickness direction of second part in second part, the projection of first cooling hole along the axial direction of first cooling hole falls on the inside of big elbow pipe.The application improves the overall strength and rigidity of the flame tube on the basis of improving the cooling effect of the part of the big elbow pipe directly opposite the main combustion zone to meet the wall temperature control requirements.

Description

Technical Field

[0001] This invention relates to the field of flame tube cooling technology, specifically to a combined cooling structure for a recirculating combustion chamber flame tube and a gas turbine engine. Background Technology

[0002] Recirculating combustors are widely used in small and medium-sized aero gas turbine engines due to their potential to shorten the axial length of engine rotors. Generally, a recirculating combustor mainly consists of a diffuser, casing, flame tube, fuel nozzle, and igniter. The flame tube is the key component of the recirculating combustor, where fuel burns to produce high-temperature, high-pressure gas that drives the turbine. As the thermodynamic cycle parameters of small and medium-sized aero gas turbine engines gradually increase, the average temperature of the gas in the main combustion zone near the flame tube head reaches as high as (2000-2500) K. To meet the requirements of the flame tube, a full-diffusion cooling technology is typically used, employing a uniform wall thickness design with a relatively small thickness (generally less than 2 mm). Multiple diverging holes with a certain angle are arranged on the flame tube wall according to a certain pattern. The cool air in the cavity between the combustor casing and the flame tube enters the high-temperature gas side inside the flame tube through the diverging holes, flowing along the high-temperature wall surface of the flame tube (i.e., the inner wall surface of the flame tube), thus achieving cooling and protection of the flame tube.

[0003] Existing flame tubes used in recirculating combustion chambers typically include a head ring, with an outer flame tube ring and an inner flame tube ring at each end. A large bend and a small bend are respectively installed at the ends of the outer and inner flame tube rings away from the head ring. The connection between the head ring and the outer flame tube ring is located near the main combustion zone, and the large bend is directly opposite the inner side of the main combustion zone. This results in high heat load intensity in these localized areas. The aforementioned fully diffused cooling structure cannot meet the wall temperature control requirements, easily leading to poor cooling in localized areas of the flame tube (the portion of the outer flame tube ring near the main combustion zone and the portion of the large bend directly opposite the main combustion zone), causing localized wall deformation or cracks. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the existing fully divergent cooling structure applied to the flame tube of the recirculation combustion chamber, which cannot meet the wall temperature control requirements and is prone to local wall deformation or cracks due to poor local cooling of the flame tube. Thus, a combined cooling structure for the flame tube of the recirculation combustion chamber and a gas turbine engine are provided.

[0005] In a first aspect, the present invention provides a combined cooling structure for a recirculating combustion chamber flame tube, comprising a head ring, an outer ring, an inner ring, a large bend, and a small bend. The inner ring and outer ring are respectively disposed at both ends of the head ring. The large bend is disposed at the end of the outer ring facing away from the head ring, and the small bend is disposed at the end of the inner ring facing away from the head ring. The structure further includes:

[0006] A first Z-shaped air film ring is disposed between the outer ring of the flame tube and the large bend. The first Z-shaped air film ring includes a first part, a second part and a third part connected in sequence. The first part is connected to the outer ring of the flame tube, the third part is connected to the large bend, and the second part is provided with a first cooling hole along the thickness direction of the second part. The projection of the first cooling hole along the axial direction of the first cooling hole falls on the inner side of the large bend.

[0007] The first mechanical gas film ring includes a first connecting portion disposed between the outer ring of the flame tube and the head ring, and a second connecting portion disposed inside the first connecting portion. A first gap is formed between the first connecting portion and the second connecting portion. A second cooling hole is provided through the first connecting portion along the thickness direction of the first connecting portion at the position corresponding to the first gap.

[0008] According to the combined cooling structure of the recirculating combustion chamber and flame tube of the present invention, at least the following technical effects are achieved:

[0009] By setting a first Z-shaped gas film ring between the outer ring of the flame tube and the large bend, and providing a first cooling hole through the second part of the first Z-shaped gas film ring, cold air can pass through the first cooling hole and flow closely along the inner side of the large bend from the end facing the outer ring of the flame tube to the end facing away from the outer ring of the flame tube. Combined with the original divergence holes of the large bend, this further promotes the wall-adhering effect of the divergent cooling gas film in the downstream region of the large bend facing away from the outer ring of the flame tube (i.e., the part of the large bend facing the main combustion zone), thus further enhancing the divergent cooling effect in this area and reducing the wall temperature gradient of the large bend. Furthermore, by setting a first mechanical gas film ring between the outer ring of the flame tube and the head ring, and providing a second cooling hole through the first connecting part of the first mechanical gas film ring, cold air can pass through the second cooling hole and contact the second connecting part. After the connection, the flow direction changes and flows along the first gap, closely adhering to the inner side of the outer ring of the flame tube. It flows from the end facing the head ring to the end away from the head ring. Combined with the original divergence holes of the outer ring of the flame tube, it further promotes the wall-adhering effect of the divergent cooling film in the area near the main combustion zone on the inner side of the outer ring of the flame tube, thereby further enhancing the divergent cooling effect in this area and reducing the wall temperature gradient of the outer ring of the flame tube. At the same time, the first Z-shaped gas film ring and the first mechanical gas film ring make the wall thickness at the connection between the outer ring of the flame tube and the large bend tube, and at the connection between the outer ring of the flame tube and the head ring, respectively. This improves the cooling effect in the local area with high heat load intensity of the flame tube and meets the wall temperature control requirements, thereby improving the overall strength and rigidity of the flame tube. It is particularly suitable for recirculation combustion chambers with relatively large size and aerodynamic force.

[0010] In an optional embodiment, a second mechanical gas film ring is further included. The second mechanical gas film ring includes a third connecting portion disposed between the inner ring of the flame tube and the head ring, and a fourth connecting portion disposed inside the third connecting portion. The third connecting portion and the fourth connecting portion form a second gap. The third connecting portion has a third cooling hole disposed through it along the thickness direction of the third connecting portion at a position corresponding to the second gap.

[0011] In one optional embodiment, a third mechanical gas film ring is provided between the inner ring of the flame tube and the small bend. The third mechanical gas film ring includes a fifth connecting portion and a sixth connecting portion. The sixth connecting portion is spaced apart on the inward side of the fifth connecting portion. The projection of the fifth connecting portion along the thickness direction of the fifth connecting portion at least partially overlaps with the sixth connecting portion. One end of the fifth connecting portion is connected to the small bend, and the other end is connected to the sixth connecting portion through a first mounting portion. The first mounting portion is provided with a fourth cooling hole through the first mounting portion along the thickness direction of the first mounting portion. The sixth connecting portion is connected to the inner ring of the flame tube.

[0012] In one optional embodiment, a fourth mechanical gas film ring is provided between the inner ring of the flame tube and the small curved tube. The fourth mechanical gas film ring includes a seventh connecting portion and an eighth connecting portion. The eighth connecting portion is spaced apart on the inward side of the seventh connecting portion. The eighth connecting portion and the seventh connecting portion are connected by a second mounting portion. A third gap is formed between the seventh connecting portion, the second mounting portion, and the eighth connecting portion. The small curved tube is disposed within the third gap and abuts against the side of the seventh connecting portion facing the eighth connecting portion. A fifth cooling hole is provided through the second mounting portion along the thickness direction of the second mounting portion. The eighth connecting portion is connected to the inner ring of the flame tube.

[0013] In one optional embodiment, a second Z-shaped gas film ring is provided between the inner ring of the flame tube and the small bend. The second Z-shaped gas film ring includes a fourth part, a fifth part, and a sixth part connected in sequence. The fourth part is located on the inward side of the sixth part. The fourth part is connected to the inner ring of the flame tube, the sixth part is connected to the small bend, and the fifth part is provided with a sixth cooling hole through the sixth part along its length.

[0014] In one optional embodiment, a turbine is disposed between the end of the small bend tube away from the inner ring of the flame tube and the end of the large bend tube away from the outer ring of the flame tube. A fifth mechanical film ring is disposed between the small bend tube and the turbine. The fifth mechanical film ring includes a ninth connecting part and a tenth connecting part. The tenth connecting part is located on the inward side of the ninth connecting part. The projection of the ninth connecting part along the thickness direction of the ninth connecting part at least partially overlaps with the tenth connecting part. One end of the ninth connecting part is connected to the turbine, and the other end is connected to the tenth connecting part through a third mounting part. The ninth connecting part, the third mounting part, and the tenth connecting part form a fourth gap. The projection of the fourth gap along the length direction of the fourth gap falls on the turbine. A seventh cooling hole is disposed through the ninth connecting part corresponding to the position of the fourth gap. The tenth connecting part is connected to the small bend tube.

[0015] Alternatively, a turbine may be provided between the end of the small curved tube away from the inner ring of the flame tube and the end of the large curved tube away from the outer ring of the flame tube. A third Z-shaped gas film ring may be provided between the inner ring of the flame tube and the turbine. The third Z-shaped gas film ring may include a seventh part, an eighth part, and a ninth part connected in sequence. The ninth part may be located on the inward side of the seventh part. The seventh part may be connected to the turbine, and the ninth part may be connected to the small curved tube. The eighth part may have an eighth cooling hole that extends through the seventh part along its length.

[0016] In one alternative embodiment, a transition pipe is provided between the large bend and the turbine, and the radius of curvature of the transition pipe is smaller than that of the large bend.

[0017] In one optional embodiment, a fourth Z-shaped air film ring is provided between the large bend and the transition pipe. The fourth Z-shaped air film ring includes a tenth part, an eleventh part, and a twelfth part connected in sequence. The twelfth part is located on the inward side of the tenth part. The tenth part is connected to the transition pipe, the twelfth part is connected to the large bend, and the eleventh part is provided with a ninth cooling hole through it along the length direction of the tenth part.

[0018] In one optional embodiment, a sixth mechanical air film ring is provided between the large bend and the transition pipe. The sixth mechanical air film ring includes an eleventh connecting portion and a twelfth connecting portion. The twelfth connecting portion is located on the inward side of the eleventh connecting portion. The projection of the eleventh connecting portion along its thickness direction at least partially overlaps with the twelfth connecting portion. One end of the eleventh connecting portion is connected to the transition pipe, and the other end is connected to the twelfth connecting portion through a fourth mounting portion. The fourth mounting portion is provided with a tenth cooling hole. The projection of the tenth cooling hole along its axial direction falls on the inner side of the transition pipe. The twelfth connecting portion is connected to the large bend.

[0019] In a second aspect, the present invention also provides a gas turbine engine, including the recirculation combustion chamber and flame tube combined cooling structure provided in the first aspect above.

[0020] Since the gas turbine engine includes a recirculation combustion chamber-flame tube combined cooling structure, which has the same beneficial effects as the recirculation combustion chamber-flame tube combined cooling structure, it will not be elaborated here. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a combined cooling structure for a recirculating combustion chamber flame tube according to this embodiment;

[0023] Figure 2 for Figure 1 A schematic diagram of the exploded structure of the middle part;

[0024] Figure 3 for Figure 2 Schematic diagram of the structure of the first Z-shaped air-film ring;

[0025] Figure 4 for Figure 2 A schematic diagram of the structure of the first mechanical air film ring in China;

[0026] Figure 5 for Figure 2 Schematic diagram of the structure of the second mechanical air film ring;

[0027] Figure 6 for Figure 2 Schematic diagram of the structure of the third mechanical air film ring;

[0028] Figure 7 for Figure 2 Schematic diagram of the fourth Z-type air film ring in the middle

[0029] Figure 8 This is a schematic diagram of the fifth mechanical film ring in a recirculating combustion chamber flame tube combined cooling structure according to this embodiment;

[0030] Figure 9 This is a schematic diagram of a recirculating combustion chamber flame tube combined cooling structure in this embodiment, in which a third mechanical gas film ring is provided between the inner ring of the flame tube and the small bend.

[0031] Figure 10 This is a schematic diagram of a recirculating combustion chamber flame tube combined cooling structure in this embodiment, in which a fourth mechanical gas film ring is provided between the inner ring of the flame tube and the small bend.

[0032] Figure 11 This is a schematic diagram of a recirculating combustion chamber flame tube combined cooling structure in this embodiment, in which a second Z-shaped gas film ring is provided between the inner ring of the flame tube and the small bend.

[0033] Figure 12 This is a cross-sectional view of the head ring in a recirculating combustion chamber flame tube combined cooling structure according to this embodiment.

[0034] Figure 13 This is a cross-sectional schematic diagram of the large bend in a recirculating combustion chamber flame tube combined cooling structure according to this embodiment.

[0035] Explanation of reference numerals in the attached figures:

[0036] 100 - Head ring, 110 - First cavity;

[0037] 200 - outer ring of the flame tube;

[0038] 300 - Inner ring of the flame tube;

[0039] 400 - Large bend, 410 - Second cavity;

[0040] 500-Small bend;

[0041] 610-First Z-type air film ring, 611-First part, 612-Second part, 613-Third part, 620-First mechanical air film ring, 621-First connecting part, 622-Second connecting part, 623-First gap, 630-Second mechanical air film ring, 631-Third connecting part, 632-Fourth connecting part, 633-Second gap, 640-Third mechanical air film ring, 641-Fifth connecting part, 642-Sixth connecting part, 643-First mounting part, 650-Fourth mechanical air film ring, 660-Second Z-type air film ring, 670-Fifth mechanical air film ring, 671-Ninth connecting part, 672-Tenth connecting part, 673-Third mounting part, 674-Fourth gap, 675-Seventh cooling hole, 680-Fourth Z-type air film ring, 681-Tenth part, 682-Eleventh part, 683-Twelfth part;

[0042] 700-Turbo;

[0043] 800-Transition tube;

[0044] 910 - Main combustion zone, 920 - Combustion channel cavity. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] In the description of this embodiment, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this embodiment. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] In the description of this embodiment, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment according to the specific circumstances.

[0048] In related technologies, the flame tube used in the recirculation combustion chamber typically includes a head ring, with an outer flame tube ring and an inner flame tube ring at each end of the head ring. A large bend and a small bend are respectively installed at the ends of the outer and inner flame tube rings away from the head ring. As the thermodynamic cycle parameters of small and medium-sized aero-gas turbine engines gradually increase, the average temperature of the main combustion zone near the flame tube head reaches as high as (2000-2500) K. To meet the requirements of the flame tube, a fully diffused cooling technology is typically used, employing a uniform wall thickness design with a relatively small thickness (generally less than 2 mm). Multiple diffused holes with a certain angle are arranged on the flame tube wall according to a certain pattern. The cold air in the cavity between the combustion chamber shell and the flame tube enters the high-temperature combustion gas side inside the flame tube through the diffused holes, flowing along the high-temperature wall surface of the flame tube (i.e., the inner wall surface of the flame tube), thereby achieving cooling and protection of the flame tube. However, the connection between the head ring and the outer ring of the flame tube is located near the main combustion zone, and the large bend section faces the inner side of the main combustion zone, resulting in high heat load intensity in these localized areas. The aforementioned fully diffused cooling structure cannot meet the wall temperature control requirements, easily leading to poor cooling in localized areas of the flame tube (the part of the outer ring of the flame tube near the main combustion zone and the part of the large bend section facing the main combustion zone), causing localized wall deformation or cracks. Related technologies increase the number of local diffusers to increase the amount of cooling air, or design the diffusers with smaller inclination angles or tangential compound angles to improve the cooling effect. However, this results in relatively poor overall rigidity and strength of the flame tube. When applied to recirculating combustion chambers with relatively large dimensions and aerodynamic forces, problems such as flame tube deformation under stress or difficulty in ensuring dimensions can easily occur, affecting the reliability of the combustion chamber structure and performance. To address the above-mentioned technical deficiencies, this invention provides a combined cooling structure for a recirculating combustion chamber flame tube and a gas turbine engine.

[0049] The following is combined with Figures 1 to 13 The following describes embodiments of the present invention.

[0050] According to a first aspect of the present invention, a recirculating combustion chamber flame tube combined cooling structure is provided, including a head ring 100, a flame tube outer ring 200, a flame tube inner ring 300, a large bend 400, and a small bend 500. The head ring 100 has the flame tube inner ring 300 and the flame tube outer ring 200 respectively disposed at its two ends. The large bend 400 is disposed at the end of the flame tube outer ring 200 opposite to the head ring 100, and the small bend 500 is disposed at the end of the flame tube inner ring 300 opposite to the head ring 100. The recirculating combustion chamber flame tube combined cooling structure further includes a first Z-shaped gas film ring 610 and a first mechanical gas film ring 620. The first Z-shaped gas film ring 610 is disposed between the flame tube outer ring 200 and the large bend 400. The first Z-shaped gas film ring 610 includes a first part 611, a second part 612, and a third part 613 connected in a Z-shape in sequence. 3. The first part 611 is connected to the outer ring 200 of the flame tube, and the third part 613 is connected to the large bend 400. The second part 612 is provided with a first cooling hole along the thickness direction of the second part 612. The projection of the first cooling hole along the axial direction of the first cooling hole falls on the inner side of the large bend 400. The first mechanical gas film ring 620 includes a first connecting part 621 disposed between the outer ring 200 of the flame tube and the head ring 100, and a second connecting part 622 disposed inside the first connecting part 621. A first gap 623 is formed between the first connecting part 621 and the second connecting part 622. The first connecting part 621 is provided with a second cooling hole through the first connecting part 621 along the thickness direction of the first connecting part 621 at the position corresponding to the first gap 623. The projection of the first gap 623 along the length direction of the first gap 623 falls on the inner wall of the inner ring 300 of the flame tube.

[0051] The recirculation combustion chamber flame tube combined cooling structure of this embodiment features a first Z-shaped gas film ring 610 between the outer ring 200 of the flame tube and the large bend 400. A first cooling hole is provided through the second part 612 of the first Z-shaped gas film ring 610, allowing cold air to pass through the first cooling hole and flow along the inner side of the large bend 400 from one end towards the outer ring 200 to the other end away from the outer ring 200. This, combined with the existing divergence holes in the large bend 400, further promotes... The wall-adhering effect of the divergent cooling gas film in the downstream region of the inner side of the large bend 400 away from the outer ring 200 of the flame tube (i.e., the part of the large bend 400 facing the main combustion zone 910) is enhanced, thereby reducing the wall temperature gradient of the large bend 400. Furthermore, a first mechanical gas film ring 620 is provided between the outer ring 200 of the flame tube and the head ring 100, and a second cooling hole is provided through the first connecting portion 621 of the first mechanical gas film ring 620, allowing the cool air... After passing through the second cooling hole and contacting the second connecting part 622, the flow direction changes and flows along the first gap 623. It also flows closely against the inner side of the outer ring 200 of the flame tube, from the end facing the head ring 100 to the end away from the head ring 100. In conjunction with the original divergence holes of the outer ring 200 of the flame tube, it further promotes the wall-adhering effect of the divergent cooling film in the area near the main combustion zone 910 on the inner side of the outer ring 200 of the flame tube, thereby further enhancing the divergent cooling effect in this area and reducing the wall temperature gradient of the outer ring 200 of the flame tube. At the same time, the first Z-shaped gas film ring 610 and the first mechanical gas film ring 620 make the wall thickness at the connection between the outer ring 200 of the flame tube and the large bend 400 and the connection between the outer ring 200 of the flame tube and the head ring 100 thicker, respectively. This improves the cooling effect in the local area with high heat load intensity of the flame tube and meets the wall temperature control requirements, thereby improving the overall strength and rigidity of the flame tube. It is particularly suitable for recirculation combustion chambers with relatively large size and aerodynamic force.

[0052] It should be noted that, Figure 1 , Figure 9 , Figure 10 , Figure 11 , Figure 12 and Figure 13 The direction indicated by the thin arrow is the direction of the cold air flow. Figure 1 The direction indicated by the medium-thick arrow is the direction of gas flow.

[0053] It should be noted that in this embodiment, the head ring 100, the outer ring 200 of the flame tube, the inner ring 300 of the flame tube, the large bend 400 and the small bend 500 form a combustion channel cavity 920. In this embodiment, the side of the component in the reflux combustion chamber flame tube combined cooling structure facing the combustion channel cavity 920 is the inner side.

[0054] It should be noted that multiple diverging holes with a certain angle are arranged on the side walls of the head ring 100, the outer ring 200 of the flame tube, the inner ring 300 of the flame tube, the large bend 400, and the small bend 500 according to a certain pattern. In conjunction with the first Z-shaped gas film ring 610 set between the outer ring 200 of the flame tube and the large bend 400, and the first mechanical gas film ring 620 set between the outer ring 200 of the flame tube and the head ring 100, the overall strength and rigidity of the flame tube are improved while meeting the need for good cooling in the entire range of the flame tube in the high-temperature rise recirculation combustion chamber. This is particularly suitable for recirculation combustion chambers with relatively large size and aerodynamic force. It is especially beneficial to improve the thermodynamic cycle parameters of gas turbine engines equipped with the recirculation combustion chamber flame tube combined cooling structure of this embodiment.

[0055] It should be noted that, in this embodiment, the outer side of the combined cooling structure of the recirculation combustion chamber and the recirculation combustion chamber shell is provided with a cavity. This cavity is provided with an air inlet for conveying cold air. The cold air enters the combustion channel cavity 920 through the divergence hole and various cooling holes, and flows on the high-temperature inner wall of the flame tube to form a divergent cooling gas film to achieve cooling and protection of the flame tube.

[0056] Considering that the connection between the inner ring 300 of the flame tube and the head ring 100 is located near the main combustion zone 910, the heat load intensity at the connection between the inner ring 300 of the flame tube and the head ring 100, as well as in the area of ​​the inner ring 300 of the flame tube near the main combustion zone 910, is high. Simply supplying cold air through the radiating holes cannot meet the wall temperature control requirements. To solve the above problems, such as... Figure 1 , Figure 2 and Figure 5As shown, in some embodiments, the recirculating combustion chamber flame tube combined cooling structure further includes a second mechanical film ring 630. The second mechanical film ring 630 includes a third connecting portion 631 disposed between the inner ring 300 of the flame tube and the head ring 100, and a fourth connecting portion 632 disposed inside the third connecting portion 631. The third connecting portion 631 and the fourth connecting portion 632 form a second gap 633. The third connecting portion 631 is provided with a third cooling hole through its thickness direction at a position corresponding to the second gap 633. This allows the cold air to pass through the third cooling hole and contact the fourth connecting portion 632, after which its flow direction changes and it flows along the second gap 633. Furthermore, the gas flows along the inner wall of the inner ring 300 of the flame tube from one end toward the head ring 100 to the other end away from the head ring 100. This, combined with the original divergence holes of the inner ring 300, further promotes the wall-adhering effect of the divergent cooling film in the area near the main combustion zone 910 on the inner side of the inner ring 300 of the flame tube, thereby further enhancing the divergent cooling effect in this area and reducing the wall temperature gradient of the inner ring 300 of the flame tube. At the same time, the second mechanical gas film ring 630 makes the wall thickness at the connection between the inner ring 300 of the flame tube and the head ring 100 thicker, thereby improving the cooling effect in the local area with high heat load intensity of the flame tube and meeting the wall temperature control requirements, while improving the overall strength and rigidity of the flame tube. This is particularly suitable for recirculation combustion chambers with relatively large size and aerodynamic forces.

[0057] Considering the large curvature of the small bend tube 500, the airflow entering the combustion channel cavity 920 through the divergence hole of the small bend tube 500 and adhering to the inner side of the small bend tube 500 is prone to separation from the inner side of the small bend tube 500, failing to achieve a good cooling effect; in order to solve the above problem, such as Figure 1 , Figure 2 , Figure 6 and Figure 9As shown, in some embodiments, a third mechanical gas film ring 640 is provided between the inner ring 300 of the flame tube and the small bend 500. The third mechanical gas film ring 640 includes a fifth connecting portion 641 and a sixth connecting portion 642. The sixth connecting portion 642 is spaced apart on the inward side of the fifth connecting portion 641. The projection of the fifth connecting portion 641 along its thickness direction partially overlaps with the sixth connecting portion 642. One end of the fifth connecting portion 641 is connected to the small bend 500, and the other end is connected to the sixth connecting portion 642 through a first mounting portion 643. The first mounting portion 643 has a fourth cooling hole penetrating along its thickness direction. The sixth connecting portion 642 is connected to the inner ring 300 of the flame tube. Cooling gas can pass through the fourth cooling hole. The cooling holes enter the space enclosed by the fifth connecting part 641 and the sixth connecting part 642, and under the guidance of the space enclosed by the fifth connecting part 641 and the sixth connecting part 642, the cooling gas flows closely to the inner side of the small bend 500 along the end facing the inner ring 300 of the flame tube and towards the end away from the inner ring 300 of the flame tube, increasing the wall adhesion effect of the divergent cooling gas film, thereby suppressing the separation of the divergent cooling gas film from the inner side of the small bend 500; further enhancing the divergent cooling effect in this part and reducing the wall temperature gradient of the small bend 500; at the same time, the third mechanical gas film ring 640 makes the wall thickness at the connection between the inner ring 300 of the flame tube and the small bend 500 thicker, thereby improving the overall strength and rigidity of the flame tube while meeting the wall temperature control requirements, which is particularly suitable for recirculation combustion chambers with relatively large size and aerodynamic force.

[0058] As another alternative implementation of the above technical solution, such as Figure 10As shown, a fourth mechanical gas film ring 650 is provided between the inner ring 300 of the flame tube and the small curved tube 500. The fourth mechanical gas film ring 650 includes a seventh connecting part and an eighth connecting part. The eighth connecting part is spaced apart on the inward side of the seventh connecting part. The eighth connecting part and the seventh connecting part are connected by a second mounting part. A third gap is formed between the seventh connecting part, the second mounting part, and the eighth connecting part. One end of the small curved tube 500 facing the inner ring 300 of the flame tube is disposed in the third gap and abuts against the side of the seventh connecting part facing the eighth connecting part. The small curved tube 500 does not contact the eighth connecting part. A fifth cooling hole is provided through the second mounting part along the thickness direction of the second mounting part. The eighth connecting part and the flame tube 650 are connected by a fifth cooling hole. The inner ring 300 is connected; cold air can enter the space enclosed by the small bend 500 and the eighth connecting part through the fifth cooling hole, and flow closely along the inner side of the small bend 500 from the end facing the inner ring 300 of the flame tube to the end away from the inner ring 300 of the flame tube, increasing the wall adhesion effect of the divergent cooling gas film on the inner side of the small bend 500, thereby suppressing the separation of the divergent cooling gas film from the inner side of the small bend 500; further enhancing the divergent cooling effect in this part and reducing the wall temperature gradient of the small bend 500; at the same time, the fourth mechanical gas film ring 650 makes the wall thickness at the connection between the inner ring 300 of the flame tube and the small bend 500 thicker, thereby improving the overall strength and rigidity of the flame tube while meeting the wall temperature control requirements, which is particularly suitable for recirculation combustion chambers with relatively large size and aerodynamic forces. Specifically, the projection of the fifth cooling hole along the axial direction of the fifth cooling hole is offset from the small bend 500.

[0059] As another alternative implementation of the above technical solution, such as Figure 11As shown, a second Z-shaped gas film ring 660 is provided between the inner ring 300 of the flame tube and the small curved tube 500. The second Z-shaped gas film ring 660 includes a fourth part, a fifth part, and a sixth part connected in a Z-shape. The fourth part is located on the inward side of the sixth part. The fourth part is connected to the inner ring 300 of the flame tube, and the sixth part is connected to the small curved tube 500. A sixth cooling hole is provided through the fifth part along the length direction of the sixth part. Cold air can pass through the sixth cooling hole and, along the length direction of the fourth part, closely adhere to the inner side of the small curved tube 500, moving away from the inner ring 300 of the flame tube. The flow at one end of the ring 300 increases the adhesion of the divergent cooling film to the inner surface of the small bend 500, thereby suppressing the separation of the divergent cooling film from the inner surface of the small bend 500. This further enhances the divergent cooling effect in this area and reduces the wall temperature gradient of the small bend 500. At the same time, the second Z-shaped film ring 660 makes the wall thickness at the connection between the inner ring 300 and the small bend 500 of the flame tube thicker. This improves the overall strength and rigidity of the flame tube while meeting the need for good cooling throughout the entire range of the flame tube in the high-temperature recirculation combustion chamber. It is particularly suitable for recirculation combustion chambers with relatively large size and aerodynamic forces.

[0060] like Figure 1 , Figure 2 and Figure 8As shown, in some embodiments, a turbine 700 is disposed between the end of the small bend 500 away from the inner ring 300 of the flame tube and the end of the large bend 400 away from the outer ring 200 of the flame tube. A fifth mechanical film ring 670 is disposed between the small bend 500 and the turbine 700. The fifth mechanical film ring 670 includes a ninth connecting portion 671 and a tenth connecting portion 672. The tenth connecting portion 672 is located on the side of the ninth connecting portion 671 facing inward. The projection of the ninth connecting portion 671 along the thickness direction of the ninth connecting portion 671 and the tenth connecting portion 672 are intersected by the projection of the tenth connecting portion 671. The 72 parts overlap. One end of the ninth connecting part 671 is connected to the turbine 700, and the other end is connected to the tenth connecting part 672 through the third mounting part 673. The ninth connecting part 671, the third mounting part 673 and the tenth connecting part 672 form a fourth gap 674. The projection of the fourth gap 674 along its length direction falls on the turbine 700. The ninth connecting part 671 is provided with a seventh cooling hole 675 through the fourth gap 674. The tenth connecting part 672 is connected to the small bend pipe 500. Because additional cooling is required for the blade roots and tips of the turbine 700 to meet the turbine 700 lifespan requirements, this embodiment provides a fifth mechanical film ring 670 between the inner ring 300 of the flame tube and the turbine 700. A seventh cooling hole 675 is provided at the ninth connecting part 671 of the fifth mechanical film ring 670. This allows the cool air to pass through the seventh cooling hole 675 and contact the tenth connecting part 672, after which its flow direction changes and it flows along the fourth gap 674. It also flows close to the inner side of the ninth connecting part 671 and blows onto the turbine 700, providing additional cooling for the blade roots and tips of the turbine 700, enhancing the cooling effect on the blade roots and tips, and meeting the turbine 700 lifespan requirements.

[0061] As an alternative implementation of the above technical solution, a turbine 700 is disposed between the end of the small bend 500 away from the inner ring 300 of the flame tube and the end of the large bend 400 away from the outer ring 200 of the flame tube. A third Z-shaped gas film ring is disposed between the inner ring 300 of the flame tube and the turbine 700. The third Z-shaped gas film ring includes a seventh part, an eighth part, and a ninth part connected in a Z-shape in sequence. The ninth part is located on the inward side of the seventh part. The seventh part is connected to the turbine 700, and the ninth part is connected to the small bend 500. The eighth part is provided with an eighth cooling hole through the length of the seventh part, and the projection of the eighth cooling hole along the length of the ninth part falls on the turbine 700; by providing a third Z-shaped air film ring between the inner ring 300 of the flame tube and the turbine 700, and providing an eighth cooling hole at the eighth part of the third Z-shaped air film ring, the cold air can pass through the eighth cooling hole and flow close to the inner side of the ninth connecting part 671 and blow onto the turbine 700, providing additional cooling to the blade root and blade tip of the turbine 700, enhancing the cooling effect on the blade root and blade tip of the turbine 700, and meeting the life requirements of the turbine 700.

[0062] like Figure 1 , Figure 2 As shown, specifically, a transition pipe 800 is provided between the large bend 400 and the turbine 700. The radius of curvature of the transition pipe 800 is smaller than that of the large bend 400. Through the transition connection of the transition pipe 800, and since the radius of curvature of the transition pipe 800 is closer to that of the small bend 500, the turbine 700 and the rocket launcher can be integrated into a whole while shortening the size of the large bend 400. Furthermore, the size of this whole is more compact, which is more advantageous for application in small and medium-sized aero gas turbine engines.

[0063] like Figure 1 , Figure 2 and Figure 7As shown, specifically, a fourth Z-shaped air film ring 680 is provided between the large bend 400 and the transition pipe 800. The fourth Z-shaped air film ring 680 includes a tenth part 681, an eleventh part 682, and a twelfth part 683 connected in a Z-shape in sequence. The twelfth part 683 is located on the inward side of the tenth part 681. The tenth part 681 is connected to the transition pipe 800, the twelfth part 683 is connected to the large bend 400, and the eleventh part 682 is provided with a first Z-shaped air film ring 683 through it along the length direction of the tenth part 681. Nine cooling holes are provided, with the projection of the ninth cooling hole along the length of the tenth part 681 falling on the turbine 700. By setting a fourth Z-shaped air film ring 680 between the large bend pipe 400 and the transition pipe 800, and setting a ninth cooling hole at the eleventh part 682 of the fourth Z-shaped air film ring 680, cold air can pass through the ninth cooling hole and flow close to the inner side of the transition pipe 800 and blow onto the turbine 700, providing additional cooling to the turbine 700 blade root and blade tip, enhancing the cooling effect on the turbine 700 blade root and blade tip, and meeting the turbine 700 life requirements.

[0064] As an alternative implementation of the above technical solution, a sixth mechanical air film ring is provided between the large bend 400 and the transition pipe 800. The sixth mechanical air film ring includes an eleventh connecting part and a twelfth connecting part. The twelfth connecting part is located on the inward side of the eleventh connecting part. The projection of the eleventh connecting part along the thickness direction of the eleventh connecting part partially overlaps with the twelfth connecting part. One end of the eleventh connecting part is connected to the transition pipe 800, and the other end is connected to the twelfth connecting part through a fourth mounting part. The fourth mounting part is provided with a tenth cooling hole. The projection of the tenth cooling hole along the axial direction of the tenth cooling hole falls on the inner side of the transition pipe 800. The twelfth connecting part is connected to the large bend 400. By setting a sixth mechanical film ring between the large bend 400 and the transition pipe 800, and setting a tenth cooling hole at the fourth mounting part of the sixth mechanical film ring, cold air can enter the space enclosed by the eleventh and twelfth connecting parts through the tenth cooling hole. Under the guidance of the space enclosed by the eleventh and twelfth connecting parts, the air flows close to the inner side of the transition pipe 800 and blows towards the turbine 700, providing additional cooling for the blade roots and tips of the turbine 700, enhancing the cooling effect on the blade roots and tips of the turbine 700, and meeting the life requirements of the turbine 700.

[0065] like Figure 12 As shown, specifically, a first cavity 110 is provided inside the head ring 100, so that the head ring 100 forms a double-wall structure to further optimize the cooling effect.

[0066] like Figure 13As shown, specifically, a second cavity 410 is provided inside the large bend 400, so that the large bend 400 forms a double-wall structure to further optimize the cooling effect.

[0067] Specifically, a third cavity is provided inside the outer ring 200 of the flame tube, so that the outer ring 200 of the flame tube forms a double-wall structure to further optimize the cooling effect.

[0068] Specifically, a fourth cavity is provided inside the inner ring 300 of the flame tube, so that the inner ring 300 of the flame tube forms a double-wall structure to further optimize the cooling effect.

[0069] It should be noted that, as Figure 2 As shown, in the combined cooling structure of the recirculating combustion chamber flame tube in this embodiment, the head ring 100, the outer ring 200 of the flame tube, the inner ring 300 of the flame tube, the large bend 400, the small bend 500, the transition tube 800, the first Z-shaped gas film ring 610, the fourth Z-shaped gas film ring 680, the first mechanical gas film ring 620, the second mechanical gas film ring 630, the third mechanical gas film ring 640, and the fifth mechanical gas film ring 670 are separately arranged to form independent parts. The head ring 100, the outer ring 200 of the flame tube, the inner ring 300 of the flame tube, the large bend 400, the small bend 500, and the transition tube 800 can be formed by sheet metal processing, and are combined with the first Z-shaped gas film ring 610, the fourth Z-shaped gas film ring 680, the first mechanical gas film ring 620, the second mechanical gas film ring 630, the third mechanical gas film ring 640, and the fifth mechanical gas film ring 670 to form an integral whole by a combined welding process, which can significantly reduce the processing cost of the flame tube.

[0070] According to a second aspect of the present invention, a gas turbine engine is also provided, including the recirculation combustion chamber-flame tube combined cooling structure provided in the first aspect of the present invention. The recirculation combustion chamber-flame tube combined cooling structure in this embodiment of the gas turbine engine provides a first Z-shaped gas film ring 610 between the outer ring 200 of the flame tube and the large bend 400, and a first cooling hole is provided through the second part 612 of the first Z-shaped gas film ring 610. This allows cold air to pass through the first cooling hole and flow close to the inner side of the large bend 400 from one end toward the outer ring 200 of the flame tube to the end away from the outer ring 200 of the flame tube, further promoting cooling in conjunction with the original divergence holes of the large bend 400. The wall-adhering effect of the divergent cooling gas film in the downstream region of the large bend 400, away from the outer ring 200 of the flame tube (i.e., the part of the large bend 400 directly opposite the main combustion zone 910), further enhances the divergent cooling effect in this area and reduces the wall temperature gradient of the large bend 400. Furthermore, a first mechanical gas film ring 620 is provided between the outer ring 200 of the flame tube and the head ring 100, and a second cooling hole is provided through the first connecting portion 621 of the first mechanical gas film ring 620, allowing the cold air to pass through the second cooling... After the orifice contacts the second connecting part 622, the flow direction changes and flows along the first gap 623. It also flows close to the inner side of the outer ring 200 of the flame tube along the end facing the head ring 100 to the end away from the head ring 100. In conjunction with the original diverging orifice of the outer ring 200 of the flame tube, it further promotes the wall-adhering effect of the diverging cooling film in the area near the main combustion zone 910 on the inner side of the outer ring 200 of the flame tube, which further enhances the diverging cooling effect in this part and reduces the wall temperature gradient of the outer ring 200 of the flame tube. At the same time, the first Z-shaped gas film ring 610 and the first mechanical gas film ring 620 make the wall thickness at the connection between the outer ring 200 of the flame tube and the large bend 400 and the connection between the outer ring 200 of the flame tube and the head ring 100 thicker, respectively. This improves the cooling effect in the local area with high heat load intensity of the flame tube and meets the wall temperature control requirements, thereby improving the overall strength and rigidity of the flame tube. It is particularly suitable for recirculation combustion chambers with relatively large size and aerodynamic force, which is beneficial to improving the thermodynamic cycle parameters of the gas turbine engine in this embodiment.

[0071] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A combined cooling structure for a recirculating combustion chamber flame tube, comprising a head ring (100), a flame tube outer ring (200), a flame tube inner ring (300), a large bend (400), and a small bend (500), wherein the head ring (100) has the flame tube inner ring (300) and the flame tube outer ring (200) respectively disposed at both ends, the large bend (400) is disposed at the end of the flame tube outer ring (200) opposite to the head ring (100), and the small bend (500) is disposed at the end of the flame tube inner ring (300) opposite to the head ring (100), characterized in that, Also includes: A first Z-shaped gas film ring (610) is disposed between the outer ring (200) of the flame tube and the large bend (400). The first Z-shaped gas film ring (610) includes a first part (611), a second part (612) and a third part (613) connected in sequence. The first part (611) is connected to the outer ring (200) of the flame tube, and the third part (613) is connected to the large bend (400). The second part (612) is provided with a first cooling hole along the thickness direction of the second part (612). The projection of the first cooling hole along the axial direction of the first cooling hole falls on the inner side of the large bend (400). The first mechanical gas film ring (620) includes a first connecting part (621) disposed between the outer ring (200) of the flame tube and the head ring (100) and a second connecting part (622) disposed inside the first connecting part (621). A first gap (623) is formed between the first connecting part (621) and the second connecting part (622). A second cooling hole is provided through the first connecting part (621) along the thickness direction of the first connecting part (621) at the position corresponding to the first gap (623). It also includes a second mechanical gas film ring (630), which includes a third connecting part (631) disposed between the inner ring (300) of the flame tube and the head ring (100) and a fourth connecting part (632) disposed inside the third connecting part (631). The third connecting part (631) and the fourth connecting part (632) form a second gap (633). The third connecting part (631) has a third cooling hole through it along the thickness direction of the third connecting part (631) at the position corresponding to the second gap (633).

2. The combined cooling structure of the recirculating combustion chamber flame tube according to claim 1, characterized in that, A third mechanical gas film ring (640) is provided between the inner ring (300) of the flame tube and the small bend (500). The third mechanical gas film ring (640) includes a fifth connecting part (641) and a sixth connecting part (642). The sixth connecting part (642) is spaced apart on the side of the fifth connecting part (641) facing inward. The projection of the fifth connecting part (641) along the thickness direction of the fifth connecting part (641) overlaps with the sixth connecting part (642) at least partially. One end of the fifth connecting part (641) is connected to the small bend (500), and the other end is connected to the sixth connecting part (642) through a first mounting part (643). The first mounting part (643) is provided with a fourth cooling hole through the first mounting part (643) along the thickness direction of the first mounting part (643). The sixth connecting part (642) is connected to the inner ring (300) of the flame tube.

3. The combined cooling structure of the recirculating combustion chamber flame tube according to claim 1, characterized in that, A fourth mechanical gas film ring (650) is provided between the inner ring (300) of the flame tube and the small curved tube (500). The fourth mechanical gas film ring (650) includes a seventh connecting part and an eighth connecting part. The eighth connecting part is spaced apart on the side of the seventh connecting part facing inward. The eighth connecting part and the seventh connecting part are connected by a second mounting part. A third gap is formed between the seventh connecting part, the second mounting part and the eighth connecting part. The small curved tube (500) is disposed in the third gap and abuts against the side of the seventh connecting part facing the eighth connecting part. A fifth cooling hole is provided through the second mounting part along the thickness direction of the second mounting part. The eighth connecting part is connected to the inner ring (300) of the flame tube.

4. The combined cooling structure of the recirculating combustion chamber and flame tube according to claim 1, characterized in that, A second Z-shaped gas film ring (660) is provided between the inner ring (300) of the flame tube and the small bend (500). The second Z-shaped gas film ring (660) includes a fourth part, a fifth part and a sixth part connected in sequence. The fourth part is located on the inward side of the sixth part. The fourth part is connected to the inner ring (300) of the flame tube, and the sixth part is connected to the small bend (500). The fifth part is provided with a sixth cooling hole through the sixth part along its length.

5. A combined cooling structure for a recirculating combustion chamber and flame tube according to any one of claims 1 to 4, characterized in that, A turbine (700) is disposed between the end of the small bend (500) away from the inner ring (300) of the flame tube and the end of the large bend (400) away from the outer ring (200) of the flame tube. A fifth mechanical film ring (670) is disposed between the small bend (500) and the turbine (700). The fifth mechanical film ring (670) includes a ninth connecting part (671) and a tenth connecting part (672). The tenth connecting part (672) is located on the inward side of the ninth connecting part (671). The projection of the ninth connecting part (671) along the thickness direction of the ninth connecting part (671) overlaps at least partially with the tenth connecting part (672). The ninth connecting part (671) is connected to the turbine (700) at one end and connected to the tenth connecting part (672) through the third mounting part (673) at the other end. The ninth connecting part (671), the third mounting part (673) and the tenth connecting part (672) form a fourth gap (674). The projection of the fourth gap (674) along the length direction of the fourth gap (674) falls on the inner side of the turbine (700). The ninth connecting part (671) is provided with a seventh cooling hole (675) through the fourth gap (674) at the position. The tenth connecting part (672) is connected to the small bend pipe (500). Alternatively, a turbine (700) may be provided between the end of the small curved tube (500) away from the inner ring (300) of the flame tube and the end of the large curved tube (400) away from the outer ring (200) of the flame tube. A third Z-shaped gas film ring may be provided between the inner ring (300) of the flame tube and the turbine (700). The third Z-shaped gas film ring may include a seventh part, an eighth part and a ninth part connected in sequence. The ninth part is located on the inward side of the seventh part. The seventh part is connected to the turbine (700), the ninth part is connected to the small curved tube (500), and the eighth part has an eighth cooling hole that runs through the seventh part along its length.

6. The combined cooling structure of the recirculating combustion chamber and flame tube according to claim 5, characterized in that, A transition pipe (800) is provided between the large bend (400) and the turbine (700), and the radius of curvature of the transition pipe (800) is smaller than that of the large bend (400).

7. The combined cooling structure of the recirculating combustion chamber flame tube according to claim 6, characterized in that, A fourth Z-shaped air film ring (680) is provided between the large bend (400) and the transition pipe (800). The fourth Z-shaped air film ring (680) includes a tenth part (681), an eleventh part (682) and a twelfth part (683) connected in sequence. The twelfth part (683) is located on the side of the tenth part (681) facing inward. The tenth part (681) is connected to the transition pipe (800), and the twelfth part (683) is connected to the large bend (400). The eleventh part (682) is provided with a ninth cooling hole through the tenth part (681) along its length.

8. The combined cooling structure of the recirculating combustion chamber and flame tube according to claim 6, characterized in that, A sixth mechanical air film ring is provided between the large bend (400) and the transition pipe (800). The sixth mechanical air film ring includes an eleventh connecting part and a twelfth connecting part. The twelfth connecting part is located on the inward side of the eleventh connecting part. The projection of the eleventh connecting part along the thickness direction of the eleventh connecting part overlaps with the twelfth connecting part at least partially. One end of the eleventh connecting part is connected to the transition pipe (800), and the other end is connected to the twelfth connecting part through a fourth mounting part. The fourth mounting part is provided with a tenth cooling hole. The projection of the tenth cooling hole along the axial direction of the tenth cooling hole falls on the inner side of the transition pipe (800). The twelfth connecting part is connected to the large bend (400).

9. A gas turbine engine, characterized in that, The reflux combustion chamber and flame tube combined cooling structure includes any one of claims 1 to 8.

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