Low-pollution combustion chamber and aero-engine

Abstract

Mixing holes are correspondingly formed in a flame tube outer ring and a flame tube inner ring of the low-pollution combustion chamber, and a quenching mixing area is formed in the space, corresponding to the mixing holes, of a combustion cavity in the axial direction of the combustion cavity. The combustion chamber forms an oil-rich combustion zone on one side, close to the flame tube head, of the quenching mixing zone, and forms a lean oil combustion zone on one side, far away from the flame tube head, of the quenching mixing zone; and the flame tube outer ring and the flame tube inner ring are bent towards the interior of the combustion cavity in the positions, close to the quenching mixing area, of the rich oil combustion area, so that the combustion cavity forms a shrinkage cavity in the quenching mixing area and the lean oil combustion area. According to the invention, the structure of the flame tube adopts a rapid shrinkage profile design, so that the radial distance between the mixing holes of the flame tube outer ring and the flame tube inner ring is shortened, the mixing jet efficiency is improved, fuel gas in a rich oil combustion area is rapidly switched to a lean oil combustion area, and low-pollution emission of the combustion chamber is realized; and meanwhile, the high-quality temperature distribution requirement of the combustion cavity outlet is met.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft engines, and in particular to a low-pollution combustion chamber and an aircraft engine using the low-pollution combustion chamber. Background Art

[0002] The combustion chamber is one of the core components of aircraft engines / gas turbines. Its function is to burn fuel, convert the chemical energy in the fuel into heat energy, increase the total enthalpy of the air entering the combustion chamber, and drive the gas turbine to do work. Its design directly affects the efficiency and emissions of aircraft engines or gas turbines. One of the main development directions of modern civil aircraft engine combustion chambers is low-pollution combustion to meet the increasingly stringent aircraft engine pollution emission standards.

[0003] The RQL (Rich burn-Quench-Lean burn) combustion technology currently used is one of the key technical routes for low pollution emissions. Its main principle is air staged combustion: the main combustion zone is the oil-rich combustion zone, the middle zone is the quenching and mixing zone, and the rear end is the oil-lean combustion zone. The RQL combustion technology is to reduce the NOx content and achieve low pollution emissions in the combustion chamber by lowering the temperature of the combustion zone and making the temperature field of the combustion zone uniform, that is, overall and local equivalence ratio control. On the basis of not increasing the complexity of the combustion chamber, the RQL combustion chamber can better avoid the problem of abnormal complexity of the flame tube and the oil supply system, and can reduce the pollution emission level to a certain extent.

[0004] RQL combustion chambers usually use air film cooling or divergent cooling to reduce the temperature of the flame tube wall, but the flame tube cooling air in the oil-rich combustion zone usually participates in the combustion, forming a series of chemically appropriate combustion areas, which limits the potential for reducing pollution emissions. In the quenching mixing zone, a single row of large mixing holes or double rows of mixing holes are usually set, and cooling air is introduced into the mixing holes to jet into the flame tube to reduce the temperature gradient of the gas and improve the uniformity of the gas, thereby realizing the conversion from oil-rich combustion to oil-lean combustion. However, the use of a single row of mixing holes cannot adjust the temperature gradient of the gas, and there is a problem of difficulty in regulating the outlet temperature distribution. The use of double rows of mixing holes will lead to a large volume of the quenching area, and there are problems such as long residence time and conversion time of the gas in the quenching area, thus forming a contradiction between low NOx emissions and high-quality outlet temperature distribution of the combustion chamber. Moreover, the flame tube of the existing RQL combustion chamber is usually large in volume and has a large radial height difference between the inner and outer rings, resulting in a large jet depth of the mixing holes in the quenching mixing zone, difficulty in cutting off high-temperature gas, and long gas conversion time. Summary of the invention

[0005] The present invention provides a low-pollution combustion chamber to solve the technical problem of the contradiction between low NOx emission and high quality outlet temperature distribution of the combustion chamber in the RQL combustion chamber in the prior art.

[0006] According to one aspect of the present invention, a low-pollution combustion chamber is provided, comprising a combustion chamber casing and a flame tube arranged in the combustion chamber casing, the flame tube comprising a flame tube head arranged at the inlet end of the combustion chamber, a flame tube outer ring connected to the outer wall of the flame tube head, and a flame tube inner ring connected to the inner wall of the flame tube head, a flow channel between the flame tube outer ring and the flame tube inner ring constitutes a combustion chamber,

[0007] Mixing holes are correspondingly arranged on the outer ring of the flame tube and the inner ring of the flame tube, and a quenching mixing zone is formed in the space corresponding to the mixing holes along the axial direction of the combustion chamber, and the combustion chamber forms an oil-rich combustion zone on the side of the quenching mixing zone close to the flame tube head, and forms an oil-lean combustion zone on the side of the quenching mixing zone away from the flame tube head;

[0008] The outer ring and the inner ring of the flame tube are bent toward the combustion chamber at a position near the quenching and mixing zone in the oil-rich combustion zone, so that the combustion chamber forms a contraction cavity in the quenching and mixing zone and the oil-lean combustion zone.

[0009] Furthermore, the mixing holes include a main mixing hole and a secondary mixing hole which are arranged at intervals along the axial direction of the combustion chamber, the main mixing hole and the secondary mixing hole are arranged correspondingly on the outer ring of the flame tube and the inner ring of the flame tube, and the main mixing hole is arranged on the side of the quenching mixing zone close to the oil-rich combustion zone;

[0010] A plurality of main mixing holes and auxiliary mixing holes are arranged on the outer ring of the flame tube and the inner ring of the flame tube, and the number of the main mixing holes is less than the number of the auxiliary mixing holes.

[0011] Furthermore, the aperture of the main mixing hole is larger than the aperture of the secondary mixing hole.

[0012] Furthermore, the axial distance between the main mixing hole and the auxiliary mixing hole is less than 1.5 times the sum of the diameters of the main mixing hole and the auxiliary mixing hole.

[0013] Furthermore, the outer ring of the flame tube and the inner ring of the flame tube both include a front straight section connected to the flame tube head and a contraction section connected to the front straight section in the oil-rich combustion zone, the contraction section is contracted in the direction toward the quenching and mixing zone, the front straight section is provided with air film cooling holes and impingement cooling holes, and the contraction section is provided with divergent cooling holes;

[0014] An air film tongue is fixed on the inner wall of the front straight section. The air film tongue extends from the front straight section to the contraction section and has a gap relative to the contraction section. The impact cooling hole is used to pass cooling air flow toward the surface of the air film tongue. The air film cooling hole is used to pass cooling air flow along the extension direction of the air film tongue. The air film tongue is used to guide the cooling air flow passed through the air film cooling holes and the impact cooling holes to form a wall-attached air film that fits the flow of the contraction section.

[0015] Furthermore, the outer ring of the flame tube and the inner ring of the flame tube both include a first middle straight section connected to the contraction section in the quenching and mixing zone, and the main mixing holes and the auxiliary mixing holes are opened in the first middle straight section.

[0016] Furthermore, the outer ring of the flame tube and the inner ring of the flame tube both include a second middle straight section connected to an end of the first middle straight section away from the flame tube head and a rear straight section connected to an end of the combustion chamber casing away from the flame tube head in the lean combustion zone, and the second middle straight section and the rear straight section are connected by a bending section to form a Z-shaped structure;

[0017] The second straight section is provided with a divergent cooling hole, and the bent section is provided with a Z-shaped ring cooling hole.

[0018] Furthermore, the combustion chamber casing comprises an outer combustion chamber casing connected to an outer ring of the flame tube and an inner combustion chamber casing connected to an inner ring of the flame tube, and the contraction cavity of the outer combustion chamber casing corresponding to the combustion chamber is set to a corresponding concave structure.

[0019] Furthermore, the flame tube also includes a vortex finder connected to the flame tube head, the vortex finder is connected to a guide plate, the guide plate is arranged in the combustion chamber and extends toward the inner wall of the flame tube, and is used to form a reflow zone at the flame tube head with the vortex finder.

[0020] According to another aspect of the present invention, an aircraft engine using the low-pollution combustion chamber is also provided.

[0021] The present invention has the following beneficial effects:

[0022] The low-pollution combustion chamber of the present invention forms a quenching mixing zone in the combustion chamber by arranging mixing holes on the outer ring of the flame tube and the inner ring of the flame tube, and forms an oil-rich combustion zone and an oil-lean combustion zone on both sides of the quenching mixing zone in the combustion chamber respectively, so that the RQL combustion technology can be used to perform air-staged combustion of the fuel gas in the combustion chamber, and the temperature of the combustion zone is reduced and the temperature field of the combustion zone is made uniform at the same time to reduce the NOx content, thereby achieving low-pollution emissions in the combustion chamber and avoiding the problem of abnormal complexity of the flame tube and the fuel supply system. The outer ring of the flame tube in the oil-rich combustion zone and one end of the inner ring of the flame tube close to the quenching and mixing zone are bent toward the inside of the combustion chamber, so that the flame tube as a whole forms an inward concave structure, and the aperture of the combustion chamber from the oil-rich combustion zone to the quenching and mixing zone is rapidly contracted, so that the radial height difference between the mixing holes on the outer ring of the flame tube and the inner ring of the flame tube in the quenching and mixing zone is reduced, thereby shortening the time for cutting off the jet through the mixing hole, and the smaller jet depth can make the mixed air flow fully mixed with the high-temperature combustion gas in a very short time to burn completely, with high combustion efficiency, effectively shortening the residence time of the combustion gas in the quenching and mixing zone, so that the combustion gas in the oil-rich combustion zone can be quickly switched to the lean combustion zone, and the combustion equivalence ratio is strictly controlled within a certain range, which can greatly reduce the NOx pollution emission of the combustion chamber; at the same time, the outlet temperature distribution of the lean combustion zone can also be regulated through the mixing hole, so that the outlet gas temperature distribution meets the turbine work requirements, ensures the stability of the combustion chamber of the aircraft engine, and enables the combustion chamber to simultaneously achieve low NOx emissions and high-quality distribution of outlet temperature. Preferably, the low-pollution combustion chamber is provided with a structure for guiding the cooling airflow to adhere to the wall when the flame is in the oil-rich combustion zone, so as to avoid the cooling air from entering the oil-rich combustion zone to participate in the combustion, and to prevent the formation of a large number of local chemically appropriate combustion areas in the oil-rich combustion zone, thereby further improving the low pollution of the combustion chamber.

[0023] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 It is a schematic structural diagram of a low-pollution combustion chamber according to a preferred embodiment of the present invention.

[0026] Legend:

[0027] 10. Combustion chamber outer casing; 20. Combustion chamber casing; 30. Flame tube head; 40. Flame tube outer ring; 50. Flame tube inner ring; 60. Swirler; 70. Diffuser; 80. Oil-rich combustion zone; 81. First front straight section; 82. Connecting section; 821. Film cooling hole; 83. Second front straight section; 831. Impingement cooling hole; 84. Contraction section; 841. Divergent cooling hole; 85. Film tongue; 90. Quenching mixing zone; 91. First middle straight section; 911. Main mixing hole; 912. Secondary mixing hole; 100. Oil-lean combustion zone; 101. Second middle straight section; 102. Rear straight section; 103. Bending section; 1031. Z-ring cooling hole; 110. Guide plate; 120. Rotating shaft. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0029] like Figure 1 As shown, the low-pollution combustion chamber of this embodiment is an annular combustion chamber arranged between the compressor and the turbine, and the annular combustion chamber rotates around the rotation axis 120. The low-pollution combustion chamber includes a combustion chamber casing and a flame tube arranged in the combustion chamber casing, the flame tube includes a flame tube head 30, a flame tube outer ring 40 connected to the outer wall of the flame tube head 30, and a flame tube inner ring 50 connected to the inner wall of the flame tube head 30, and the flow channel between the flame tube outer ring 40 and the flame tube inner ring 50 constitutes a combustion chamber for fuel to burn. The combustion chamber casing is connected to the diffuser 70, and the diffuser 70 is connected to the compressor to pass the high-pressure air compressed by the compressor into the combustion chamber. The flame tube head 30 is arranged at the inlet end of the combustion chamber to connect with the fuel nozzle to pass fuel into the combustion chamber, and a vortex finder 60 connected to the flame tube head 30 is used to form a reflow zone at the flame tube head to mix the fuel and high-pressure air and promote the atomization of the fuel, so that the fuel-gas mixture burns stably in the combustion chamber, and the heat energy generated by the combustion is output toward the turbine at the outlet end of the combustion chamber to provide power for the rotation of the turbine. Specifically, the diffuser 70 passes the high-pressure air compressed by the compressor into the area between the combustion chamber casing and the flame tube through the diffuser 70 flow channel, and then the high-pressure air enters the combustion chamber through the openings on the flame tube outer ring 40, the flame tube inner ring 50 and the flame tube head 30, and the fuel enters the combustion chamber through the fuel nozzle. The vortex generator 60 allows the incoming airflow to form a recirculation zone at the flame tube head 30 to promote the airflow and the incoming fuel to be fully mixed at the inlet end of the combustion chamber. When the combustion chamber is ignited and started, the ignition nozzle arranged at the inlet end of the combustion chamber ignites the mixed fuel-gas mixture, so that the ignited fuel-gas mixture forms a stable fire source in the combustion chamber for combustion and flows from the inlet end to the outlet end, and then the turbine at the outlet end of the combustion chamber converts the heat energy generated by the combustion of the fuel in the combustion chamber into kinetic energy to do work for the turbine.

[0030] Mixing holes are correspondingly arranged on the flame tube outer ring 40 and the flame tube inner ring 50, and the space corresponding to the mixing holes along the axial direction of the combustion chamber forms a quenching mixing zone 90, and the combustion chamber forms an oil-rich combustion zone 80 on the side of the quenching mixing zone 90 close to the flame tube head 30, and forms an oil-lean combustion zone 100 on the side of the quenching mixing zone 90 away from the flame tube head. Therefore, the oil-rich combustion zone 80 at the inlet end of the combustion chamber constitutes a main combustion zone because it is in a high-temperature, high-oxygen, and high-fuel environment. The quenching mixing zone 90 injects a high-speed cooling airflow into the mixing holes to jet the fuel mixture flowing into the oil-rich combustion zone 80, so as to cut off the high-temperature fuel gas and further mix the airflow, and at the same time reduce the temperature gradient of the fuel gas, so that the fuel gas that meets the temperature field enters the oil-lean combustion zone 100 for combustion, so that low pollution emissions can be achieved by performing staged combustion of the fuel gas using the RQL combustion technology. The outer ring 40 of the flame tube and the inner ring 50 of the flame tube are bent toward the combustion chamber at the position of the rich combustion zone 80 near the quenching and mixing zone 90, so that the combustion chamber forms a contraction cavity in the quenching and mixing zone 90 and the lean combustion zone 100, so that the flame tube adopts a rapid contraction profile design, so that the aperture of the combustion chamber from the rich combustion zone 80 to the quenching and mixing zone 90 is rapidly contracted, so that the radial height difference between the mixing holes at the position of the quenching and mixing zone 90 on the outer ring 40 of the flame tube and the inner ring 50 of the flame tube is reduced, so that the time for the cooling airflow to enter the quenching and mixing zone 90 through the mixing holes to cut off the jet is shortened, and the smaller jet depth can make the mixed airflow in a very short time time to fully mix with the high-temperature combustion gas for complete combustion, with high combustion efficiency, effectively shortening the residence time of the combustion gas in the quenching and mixing zone 90, so that the fuel-gas mixture in the oil-rich combustion zone 80 can be quickly switched to the lean combustion zone 100, and the cooling airflow introduced into the quenching and mixing zone 90 meets the optimal range of the combustion equivalence ratio, which can greatly reduce the NOx pollution emission of the combustion chamber; at the same time, through the design of the mixing holes, the temperature distribution of the outlet of the lean combustion zone 100 can also be regulated, so that the gas temperature distribution at the outlet meets the turbine work requirements, ensuring the stability of the aircraft engine combustion chamber, and enabling the combustion chamber to achieve low NOx emissions and high-quality distribution of outlet temperature at the same time.

[0031] like Figure 1As shown, the mixing holes include a main mixing hole 911 and a secondary mixing hole 912 which are arranged at intervals along the axial direction of the combustion chamber. The main mixing hole 911 and the secondary mixing hole 912 are both circumferentially arranged on the outer ring 40 of the flame tube and the inner ring 50 of the flame tube, and the main mixing hole 911 is arranged on the side of the quenching mixing zone 90 close to the oil-rich combustion zone 80. The combustion chamber between the main mixing hole 911 and the secondary mixing hole 912 forms a quenching mixing zone 90, so as to cut off the high-temperature combustion gas flowing to the quenching mixing zone 90 by introducing a mixing cooling airflow into the main mixing hole 911 and the secondary mixing hole 912, and fully mix the mixing airflow with the high-temperature combustion gas to reduce its temperature gradient, thereby adjusting the temperature distribution at the combustion chamber outlet. Preferably, multiple main mixing holes 911 and secondary mixing holes 912 are arranged at circumferential intervals along the flame tube outer ring 40 and the flame tube inner ring 50, and the multiple main mixing holes 911 and the multiple secondary mixing holes 912 are equidistantly arranged, the number of main mixing holes 911 is less than the number of secondary mixing holes 912, and the aperture of the main mixing holes 911 is larger than the aperture of the secondary mixing holes 912, so that the main mixing holes 911 are designed with a large aperture and a small number of holes to efficiently cut off the high-temperature combustion gas flowing in from the oil-rich combustion zone 80, and the secondary mixing holes 912 are designed with a small aperture and a large number of holes, which can better adjust the temperature gradient, so that the temperature distribution coefficient at the outlet end of the combustion chamber meets the requirements, so that the combustion chamber can achieve low NOx emissions and high-quality distribution of outlet temperature.

[0032] like Figure 1 As shown, the axial spacing between the main mixing hole 911 and the auxiliary mixing hole 912 is less than 1.5 times the sum of the apertures of the main mixing hole 911 and the auxiliary mixing hole 912. Thus, by adopting an ultra-short distance symmetrical jet quenching design between the main mixing hole 911 and the auxiliary mixing hole 912, the mixed cooling airflow introduced into the main mixing hole 911 can perform efficient jet interception on the high-temperature combustion gas flowing into the quenching mixing zone 90, and then quickly adjust the temperature gradient of the combustion gas through the auxiliary mixing hole 912 to meet the temperature field requirement of the lean combustion zone 100, greatly shortening the residence time of the high-temperature combustion gas in the quenching mixing zone 90, realizing a rapid conversion from the fuel-gas mixture of the rich combustion zone 80 to the lean combustion zone 100, greatly improving the combustion efficiency, and realizing low pollution emissions of the combustion chamber.

[0033] like Figure 1As shown, the flame tube outer ring 40 and the flame tube inner ring 50 both include a front straight section and a contraction section 84 connected to the front straight section in the oil-rich combustion zone 80. Specifically, the front straight section includes a first front straight section 81, a second front straight section 83, and a connecting section 82 arranged between the first front straight section 81 and the second front straight section 83. The first front straight section 81 is connected to the flame tube head 30, and the connecting section 82 is arranged along the radial direction of the combustion chamber toward the direction away from the combustion chamber and is respectively fixed to the first front straight section 81 and the second front straight section 83. The contraction section 84 is connected to the end of the second front straight section 83 away from the flame tube head 30, and the contraction section 84 is contracted in the direction toward the quenching mixing zone 90.

[0034] An air film cooling hole 821 is opened on the wall surface of the connecting section 82, and an impingement cooling hole 831 is opened on the wall surface of the second front straight section 83, so that the second front straight section 83 passes a cooling air flow into the combustion chamber through the impingement cooling hole 831, and the connecting section 82 passes a cooling air flow into the combustion chamber through the air film cooling hole 821, so as to cool the wall surface of the flame tube. An air film tongue 85 is fixed on the inner wall of the front straight section. The air film tongue 85 is fixed on the inner wall of the connection between the first front straight section 81 and the connecting section 82 and extends from the second front straight section 83 to the contraction section 84. The air film tongue 85 has a gap relative to the contraction section 84, so that the cooling airflow entering the air film cooling hole 821 of the connecting section 82 and the impact cooling hole 831 of the second front straight section 83 can be guided by the air film tongue 85 to form a wall-adhering air film that fits the flow of the contraction section 84. The wall-adhering effect generated by the contraction profile of the contraction section 84 is utilized to not only enhance the cooling effect on the wall of the flame tube, but also avoid the cooling air in the entire oil-rich combustion zone 80 from participating in the combustion, thereby ensuring efficient cooling while reducing NOx emissions. A divergent cooling hole 841 is opened on the wall of the contraction section 84, so that the flame tube is cooled in the oil-rich combustion zone 80 by combining air film cooling, impact cooling and divergent cooling, further enhancing the cooling effect.

[0035] like Figure 1As shown, the flame tube outer ring 40 and the flame tube inner ring 50 both include a first straight section 91 in the quenching mixing zone 90 . The first straight section 91 is connected to the end of the contraction section 84 away from the flame tube head 30 . The main mixing hole 911 and the auxiliary mixing hole 912 are opened on the first straight section 91 . As a result, the quenching and mixing zone 90 is located at the contraction surface position of the flame tube outer ring 40 and the flame tube inner ring 50, so that the radial distance between the main mixing hole 911 and the auxiliary mixing hole 912 between the flame tube outer ring 40 and the flame tube inner ring 50 is greatly shortened, so that the jet depth of the mixed gas is reduced, and the high-temperature combustion gas can be quickly cut off, so that the low-temperature mixing air entering the mixing hole can be quickly and evenly mixed with the combustion products of the oil-rich combustion zone 80, which greatly shortens the residence time of the high-temperature combustion gas in the quenching and mixing zone 90, improves the combustion efficiency, realizes the rapid conversion of the combustion gas from the oil-rich combustion zone 80 to the oil-lean combustion zone 100, reduces the temperature of the combustion products, and greatly reduces the generation of NOx.

[0036] like Figure 1 As shown, the outer ring 40 of the flame tube and the inner ring 50 of the flame tube in the lean combustion zone 100 both include a second straight section 101 connected to the first straight section 91, a rear straight section 102 arranged at the outlet end of the combustion chamber, and a bent section 103 arranged between the second straight section 101 and the rear straight section 102. The bent section 103 extends along the radial direction of the combustion chamber toward the outside of the combustion chamber and connects the second straight section 101 and the rear straight section 102 respectively, so that the second straight section 101 and the rear straight section 102 are connected to form a Z-shaped structure through the bent section 103. The second straight section 101 is provided with a divergent cooling hole 841, and the bent section 103 is provided with a Z-shaped ring cooling hole. The divergent cooling hole 841 and the Z-shaped ring cooling hole are both arranged toward the outlet end of the combustion chamber, so that the wall surface of the outer ring 40 of the flame tube and the inner ring 50 of the flame tube can be cooled by combining divergent cooling and Z-shaped ring cooling in the lean combustion zone 100. The Z-shaped structure can form a certain flow velocity and pressure distribution when the cooling airflow passes through the Z-shaped ring cooling hole, so as to form a stable cooling air film on the wall of the flame tube. The cooling air film can not only isolate the direct contact between the fuel gas in the lean combustion zone 100 and the flame tube wall, thereby reducing the wall temperature, but also can take away part of the heat through the flow of the airflow, so as to adjust the temperature distribution at the outlet of the combustion chamber to meet the requirements of the engine. Preferably, the flow rate and flow velocity of the cooling airflow can be controlled by changing the parameters such as the diameter, number and distribution of the Z-shaped ring cooling holes, so as to optimize the temperature distribution at the outlet of the combustion chamber, so as to meet the requirements for the cooling of the flame tube under different working conditions.

[0037] like Figure 1As shown, the combustion chamber casing includes an outer combustion chamber casing 10 connected to the outer ring 40 of the flame tube and an inner combustion chamber casing 20 connected to the inner ring 50 of the flame tube. The contraction cavity of the combustion chamber corresponding to the outer combustion chamber casing 10 is set to a corresponding concave structure, which can reduce the overall volume of the combustion chamber, reduce the weight of the combustion chamber to a large extent, improve the thrust-to-weight ratio of the aircraft engine, and reduce energy consumption and emissions.

[0038] like Figure 1 As shown, the vortex finder 60 is connected to a guide plate 110, which is arranged in the combustion chamber and extends toward the wall of the flame tube outer ring 40 and the flame tube inner ring 50, and its end away from the vortex finder 60 extends toward the direction of the combustion chamber outlet end, so that the setting of the guide plate 110 can, on the one hand, isolate the high-temperature radiation of the oil-rich combustion zone 80 and protect the wall of the flame tube head 30 from direct impact and ablation of the high-temperature combustion gas; on the other hand, it can form a reflow zone with the vortex finder 60 at the flame tube head 30, optimize the flow field characteristics in the combustion chamber, promote the atomization and mixing of the fuel in the oil-rich combustion zone 80, so as to form a stable flame in the oil-rich combustion zone 80 and improve the combustion efficiency and combustion stability.

[0039] In addition, the present invention also discloses an aero-engine, which comprises the above-mentioned low-pollution combustion chamber.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-pollution combustion chamber, comprising a combustion chamber casing and a flame tube arranged in the combustion chamber casing, wherein the flame tube comprises a flame tube head (30), a flame tube outer ring (40) connected to the outer wall of the flame tube head (30), and a flame tube inner ring (50) connected to the inner wall of the flame tube head (30), wherein a flow channel between the flame tube outer ring (40) and the flame tube inner ring (50) constitutes a combustion chamber, and wherein: Mixing holes are correspondingly arranged on the flame tube outer ring (40) and the flame tube inner ring (50); a quenching mixing zone (90) is formed in the combustion chamber along the axial direction of the space corresponding to the mixing holes; and the combustion chamber forms an oil-rich combustion zone (80) on the side of the quenching mixing zone (90) close to the flame tube head (30), and forms an oil-lean combustion zone (100) on the side of the quenching mixing zone (90) away from the flame tube head (30); The flame tube outer ring (40) and the flame tube inner ring (50) are both bent toward the combustion chamber at a position close to the quenching and mixing zone (90) in the oil-rich combustion zone (80), so that the combustion chamber forms a contraction cavity in the quenching and mixing zone (90) and the oil-lean combustion zone (100).

2. The low-pollution combustion chamber according to claim 1, characterized in that: The mixing holes include a main mixing hole (911) and a secondary mixing hole (912) which are arranged at intervals along the axial direction of the combustion chamber, the main mixing hole (911) and the secondary mixing hole (912) are arranged correspondingly on the flame tube outer ring (40) and the flame tube inner ring (50), and the main mixing hole (911) is arranged on a side of the quenching mixing zone (90) close to the oil-rich combustion zone (80); A plurality of the main mixing holes (911) and the secondary mixing holes (912) are arranged on the outer ring (40) of the flame tube and the inner ring (50) of the flame tube, and the number of the main mixing holes (911) is less than the number of the secondary mixing holes (912).

3. The low-pollution combustion chamber according to claim 2, characterized in that: The aperture of the main mixing hole (911) is larger than the aperture of the secondary mixing hole (912).

4. The low-pollution combustion chamber according to claim 2, characterized in that: The axial distance between the main mixing hole (911) and the auxiliary mixing hole (912) is less than 1.5 times the sum of the diameters of the main mixing hole (911) and the auxiliary mixing hole (912).

5. The low-pollution combustion chamber according to claim 2, characterized in that: The flame tube outer ring (40) and the flame tube inner ring (50) both comprise a front straight section connected to the flame tube head (30) and a contraction section (84) connected to the front straight section in the oil-rich combustion zone (80); the contraction section (84) is contracted in a direction toward the quenching and mixing zone (90); the front straight section is provided with air film cooling holes (821) and impingement cooling holes (831); and the contraction section (84) is provided with divergent cooling holes (841); An air film tongue (85) is fixed on the inner wall of the front straight section, and the air film tongue (85) extends from the front straight section to the contraction section (84) and has a gap relative to the contraction section (84). The impact cooling hole (831) is used to pass a cooling air flow toward the surface of the air film tongue (85), and the air film cooling hole (821) is used to pass a cooling air flow along the extension direction of the air film tongue (85). The air film tongue (85) is used to guide the cooling air flow passed through the air film cooling hole (821) and the impact cooling hole (831) to form a wall-attached air film that flows in close contact with the contraction section (84).

6. The low-pollution combustion chamber according to claim 5, characterized in that: The flame tube outer ring (40) and the flame tube inner ring (50) both include a first middle straight section (91) connected to the contraction section (84) in the quenching mixing zone (90), and the main mixing hole (911) and the secondary mixing hole (912) are opened on the first middle straight section (91).

7. The low-pollution combustion chamber according to claim 6, characterized in that: The flame tube outer ring (40) and the flame tube inner ring (50) both comprise, in the lean combustion zone (100), a second middle straight section (101) connected to an end of the first middle straight section (91) away from the flame tube head (30) and a rear straight section (102) connected to an end of the combustion chamber casing away from the flame tube head (30), wherein the second middle straight section (101) and the rear straight section (102) are connected via a bending section (103) to form a Z-shaped structure; The second middle straight section (101) is provided with a divergent cooling hole (841), and the bent section (103) is provided with a Z-shaped ring cooling hole.

8. The low-pollution combustion chamber according to claim 1, characterized in that: The combustion chamber casing comprises an outer combustion chamber casing (10) connected to the outer ring (40) of the flame tube and an inner combustion chamber casing (20) connected to the inner ring (50) of the flame tube. The outer combustion chamber casing (10) is configured as a corresponding concave structure corresponding to the contraction cavity of the combustion chamber.

9. The low-pollution combustion chamber according to claim 1, characterized in that: The flame tube also includes a vortex finder (60) connected to the flame tube head (30), and the vortex finder (60) is connected to a guide plate (110). The guide plate (110) is arranged in the combustion chamber and extends toward the inner wall of the flame tube, and is used to form a reflow zone with the vortex finder (60) at the flame tube head (30).

10. An aircraft engine, characterized in that: A low-pollution combustion chamber comprising the low-pollution combustion chamber according to any one of claims 1 to 9.

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