Anti-carbon-deposition combined fuel oil atomization device

Abstract

The invention belongs to the technical field of aero-engines, and discloses an anti-carbon-deposition combined fuel oil atomization device which comprises a fuel oil nozzle, a swirler, a heat screen and a flame tube head. The fuel nozzle is fixedly connected with the combustion chamber outer casing, the flame tube head is fixedly arranged on the flame tube, the heat shield is connected with the flame tube head, the swirler is detachably connected with the heat shield, and the other end of the fuel nozzle is inserted into the swirler; the fuel nozzle comprises a nozzle body and an outer cover, the nozzle body comprises a main nozzle and an auxiliary nozzle, the main nozzle and the auxiliary nozzle are pressed and fixed on the nozzle body through the outer cover, a plurality of first air inlet holes are formed in the outer cover, and blowing carbon gas enters from the first air inlet holes. The fuel nozzle, the swirler, the flame tube head and the like are designed in a matched mode, atomization is enhanced, the distribution range of an oil mist field is expanded, the ignition and cross-flame capacity of the combustion chamber is improved, the temperature field of the combustion chamber is improved, the risk of carbon deposition of the nozzle and the flame tube head is reduced, the use stability is good, and the use envelope of an engine is widened.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine technology, and specifically relates to a combined fuel atomization device for preventing carbon buildup. Background Technology

[0002] Existing aero gas turbine engine combustion chamber structures, such as Figure 1 As shown, it mainly includes an outer combustion chamber casing 1, an inner combustion chamber casing 2, a flame tube 3, and a fuel nozzle 4. The fuel main pipe is responsible for supplying fuel, and the fuel nozzle 4 is responsible for atomizing the fuel and injecting it into the flame tube 3 for combustion. The atomization quality of the fuel directly affects the temperature field and ignition performance of the combustion chamber within the flame tube 3. Poor fuel atomization will lead to a deterioration in the quality of the temperature field. Therefore, ensuring the quality of fuel atomization is an important issue that needs to be addressed in the design process for the combustion chamber of an aero-gas turbine engine.

[0003] Current fuel nozzles mainly include dual-path centrifugal nozzles and pneumatic atomizing nozzles. They can generate fuel spray that meets usage requirements by utilizing the nozzle itself or matching it with a vortex generator. To ensure the quality of fuel atomization in the combustion chamber, existing technologies typically carry out technical improvements in two aspects: one is to ensure the design performance of the atomizing device, which must meet the fuel atomization performance requirements under design conditions; the other is to improve the stability of the atomizing device during use, avoiding deterioration of atomization performance due to carbon deposits or erosion during use. However, existing fuel nozzles cannot guarantee both aspects simultaneously.

[0004] For small and medium-sized aero gas turbine engines, the solutions for improving fuel atomization quality generally focus on the structural optimization of individual nozzle components. However, due to the limited design space and performance boundaries of individual components, this type of optimization method has obvious technical bottlenecks: on the one hand, it is difficult to broaden the effective operating condition boundary of fuel atomization and cannot adapt to complex and ever-changing flight conditions; on the other hand, its ability to prevent backfire and carbon buildup is limited and cannot meet the special needs under extreme conditions.

[0005] In summary, existing technologies can only alleviate the problem of carbon buildup in nozzles and flame tube heads to a certain extent through local structural improvements, but cannot fundamentally eliminate it. Furthermore, under extreme conditions such as high altitude, extreme cold, and high intake air temperature, carbon buildup poses a risk of worsening the temperature field and making ignition difficult, which seriously affects the operating envelope of aero gas turbine engines. Summary of the Invention

[0006] To address the above problems, the present invention provides a combined fuel atomizing device for preventing carbon buildup, comprising a fuel nozzle, a vortex generator, a heat shield, and a flame tube head; One end of the fuel nozzle is fixedly connected to the outer casing of the combustion chamber, the head of the flame tube is fixedly set at the end of the flame tube near the fuel nozzle, the heat shield is connected to the head of the flame tube, the vortex generator is detachably connected to the heat shield, and the other end of the fuel nozzle is inserted into the vortex generator. The fuel injector includes an injector body and an outer cover. One end of the injector body is fixedly connected to the outer casing of the combustion chamber. The other end of the injector body is provided with a main injector and an auxiliary injector. The main injector is fitted outside the auxiliary injector. The outer cover is fitted outside the main injector and is detachably connected to the outside of the injector body. The outer cover presses and fixes the main injector and auxiliary injector onto the injector body. A third channel is formed between the inner wall of the outer cover and the outer wall of the main injector. Multiple first air inlets are provided circumferentially inside the inner wall of the outer cover. The outlet of each first air inlet is connected to the third channel. Carbon deposit gas enters from the first air inlet.

[0007] Furthermore, the first air inlet extends radially along the wall of the outer cover, and the axis of the first air inlet forms an acute angle with the axial centerline of the outer cover.

[0008] Furthermore, the nozzle body is provided with a main oil passage and a secondary oil passage. The secondary nozzle has a first channel connected to the secondary oil passage along the axial direction. The inner wall of the main nozzle and the secondary nozzle have a second channel, which is connected to the main oil passage.

[0009] Furthermore, the third channel includes an annular section between the inner wall of the outer casing and the outer wall of the main nozzle, and a conical section near the outlet of the main nozzle.

[0010] Furthermore, the area ratio of the first air inlet to the conical section of the third channel is 1.4 to 1.5.

[0011] Furthermore, the vortex generator includes a primary vortex generator, a secondary vortex generator, and an annular cover plate; The secondary eddy current generator is detachably connected to the heat shield, and the annular cover plate is fixedly connected to the end face of the secondary eddy current generator away from the heat shield, forming a movable gap. The annular cover plate presses the primary eddy current generator onto the end face of the secondary eddy current generator away from the heat shield, and the primary eddy current generator can move radially in the movable gap. The first-stage vortex generator has a first receiving cavity arranged axially inside, and the outer cover is inserted into the first receiving cavity. The inner wall of the first receiving cavity is provided with a slope at the end near the fuel nozzle, and the outer wall of the outer cover is provided with a recessed platform at the inlet of each first air inlet.

[0012] Furthermore, the outer wall of the first-stage vortex generator is provided with a cylindrical section and a conical section in sequence along the direction close to the second-stage vortex generator. The conical section of the first-stage vortex generator is provided with multiple second air inlets in the circumferential direction. The second air inlets extend radially along the wall of the conical section of the first-stage vortex generator. Each second air inlet is connected to the first receiving cavity. The axis of the second air inlet is at an acute angle to the axial centerline of the first-stage vortex generator.

[0013] Furthermore, the area ratio of the annular section of the second air intake to that of the third channel is 4.8 to 4.9.

[0014] Furthermore, the second-stage vortex generator includes a venturi tube, a guide ring, and blades; The venturi tube has a flange at the end near the first-stage vortex generator. The flange is fixedly connected to the annular cover plate on the side facing the first-stage vortex generator. A guide ring is sleeved on the end of the venturi tube away from the first-stage vortex generator. There is a first gap between the end face of the guide ring near the first-stage vortex generator and the side of the flange facing away from the first-stage vortex generator. There is a second gap between the inner wall of the guide ring and the outer wall of the venturi tube. The first gap and the second gap are interconnected to form a fourth channel. Multiple blades are arranged in the first gap and are evenly distributed along the circumference of the guide ring. Each blade extends along the guide ring, and the two sides of each blade in the axial direction are fixedly connected to the end face of the guide ring near the first-stage vortex generator and the side of the flange facing away from the first-stage vortex generator, respectively. The inner cavity of the venturi tube is connected to the first receiving cavity. The inner cavity of the venturi tube includes a contraction section, a first straight section and an expansion section arranged sequentially along the gas flow direction. The outlet of the fourth channel is connected to the outlet of the venturi tube, and the outlet of the guide ring is flared.

[0015] Furthermore, the outlet angle α of the guide ring is not less than 120°, and the end face of the guide ring is flush with the wall surface of the heat insulation screen.

[0016] Furthermore, the inner wall cross-section of the guide ring is provided with a circular arc segment and a second straight segment in sequence along the gas flow direction at the outlet of the venturi tube, wherein the radius of the circular arc segment gradually increases along the gas flow direction.

[0017] Furthermore, the arc segment is also provided with a first pointed protrusion and a second pointed protrusion, and the surface between the first pointed protrusion and the second pointed protrusion is the same as that of the arc segment.

[0018] Furthermore, the wall of the heat shield has a uniform wall thickness structure, the shape of the heat shield matches the head of the flame tube, and there is a gap between the side of the heat shield facing the head of the flame tube and the head of the flame tube. The flame tube head is provided with a mounting hole, and the heat shield is provided with a first boss. The first boss is clearance-fitted with the mounting hole. The heat shield is also provided with a second internal thread hole that passes through the first boss. The outer wall of the guide ring is provided with a second external thread, which is threadedly connected to the second internal thread hole. Two second bosses are provided on the side of the heat shield facing the flame tube head. The two second bosses are located on both sides of the second internal thread hole, and each second boss extends radially along the heat shield.

[0019] Furthermore, the flame tube head is annularly flat, and an installation edge is provided on the outer side of the flame tube head. The installation edge is fixedly connected to the end of the flame tube near the fuel nozzle. Multiple third protrusions are provided circumferentially at intervals on the inner side of the installation edge of the flame tube head, and a mounting hole is provided through each third protrusion.

[0020] Furthermore, the surface of the flame tube head is also provided with a first cooling hole, a second cooling hole, a third cooling hole, a fourth cooling hole, and a fifth cooling hole; Each third protrusion is provided with multiple first cooling holes, which are arranged in a ring array. The center point of the ring array is the center of the third protrusion, and the direction of the ring array is the circumference of the third protrusion. Each third boss has multiple second cooling holes on its outer side. The multiple second cooling holes are arranged in a ring array. The center point of the ring array is the center of the third boss, and the direction of the ring array is the circumference of the third boss. The flame tube head is symmetrically provided with multiple sets of third cooling holes on both sides of each third protrusion. Adjacent sets of third cooling holes are distributed circumferentially along the flame tube head. Each set of third cooling holes includes multiple third cooling holes distributed radially along the flame tube head. Multiple fourth cooling holes are provided at intervals along the circumference on the outer edge of the flame tube head near the mounting edge, and multiple fifth cooling holes are provided at intervals along the circumference on the inner edge of the flame tube head away from the mounting edge.

[0021] The beneficial effects of this invention are: 1. This invention provides a matching design for related parts such as fuel nozzles, swirl generators, and flame tube heads, forming a cooperative relationship between them. This can enhance atomization, expand the distribution range of the fuel mist field, improve the ignition and flame connection capability of the combustion chamber, and improve the temperature field of the combustion chamber. It greatly reduces the risk of carbon buildup on the nozzles and flame tube heads, has good stability in use, and broadens the engine's service envelope.

[0022] 2. This invention has a reliable anti-carbon deposit function. The head of the fuel nozzle is provided with a carbon-blowing structure that can form a carbon-blowing gas to prevent carbon deposits from forming on the head of the fuel nozzle. The carbon-blowing gas and the air intake from the first-stage vortex generator form a matching airflow generated in the venturi tube, which can prevent the flow field at the vortex generator outlet from flowing back and avoid high-temperature gas from entering the venturi tube and aggravating carbon deposits on the nozzle head.

[0023] 3. The outer wall of the outer cover of the present invention is provided with a strip-shaped recess at the inlet of each first air inlet, and the inner wall of the first receiving cavity of the first stage vortex is provided with a slope at the end near the fuel nozzle to prevent the first air inlet from being blocked by the edge of the vortex due to the expansion of the parts under hot conditions.

[0024] 4. The outer casing of this invention forms a carbon-blowing airflow channel between itself and the main nozzle, resulting in uniform carbon-blowing gas at the main nozzle outlet. This prevents carbon buildup at the main nozzle outlet. The airflow converges from the annular section of the third channel to the conical section at the nozzle outlet, which can limit the fuel mist cone angle of the main nozzle to a certain extent, preventing excessive fuel injection onto the venturi tube of the vortex generator and reducing carbon buildup in the venturi tube. The area ratio of the first air inlet to the conical section of the third channel is 1.4 to 1.5. The tapered structure accelerates the carbon-blowing gas. The size of the conical section is controlled between 0.4 and 0.5 mm to prevent excessive carbon-blowing gas volume and to prevent fuel splashed inside the venturi tube from entering the carbon-blowing structure under extreme operating conditions.

[0025] 5. The area ratio of the second air inlet of the first-stage vortex generator to the annular section of the third channel of the carbon blowing structure is 4.8 to 4.9, which ensures that the gas volume and flow rate at the Venturi tube outlet can prevent high-temperature combustion gas from flowing back into the Venturi tube, causing carbon buildup in the fuel nozzle 4. At the same time, it also avoids excessive gas volume and flow rate at the Venturi tube outlet, which could impact and damage the downstream flow field of the flame tube head 7.

[0026] 6. The maximum spray cone angle after the nozzle and vortex generator of the present invention are matched is no more than 80°, which can ensure that the edge of the spray cone is near the intersection point B of the contraction section of the venturi tube and the first straight section, avoid fuel vertically impacting the wall of the contraction section of the venturi tube, reduce fuel splashing inside the venturi tube, and also avoid fuel backflow along the venturi tube, which can reduce fuel accumulation and carbon deposits on the nozzle, the first-stage vortex generator and the inner wall of the venturi tube.

[0027] 7. The outlet of the guide ring of the present invention is flared, the outlet angle α of the guide ring is not less than 120°, and the end face of the guide ring is slightly higher than the heat insulation screen wall surface, so as to ensure that the airflow at the outlet of the vortex generator can flow along the heat insulation screen wall surface, but will not excessively scour the wall surface, thereby increasing the coverage area of ​​the recirculation zone at the head of the flame tube while reducing the carbon area of ​​the heat insulation screen wall.

[0028] 8. The arc segment of the secondary vortex generator of the present invention is further provided with a first pointed protrusion and a second pointed protrusion, which can increase the airflow disturbance on the wall surface and prevent a large amount of fuel from adhering to the outlet wall surface of the vortex generator to form carbon deposits. The profile between the first pointed protrusion and the second pointed protrusion is consistent with the arc segment to avoid gas wall separation.

[0029] 9. The flame tube head of the present invention is an annular plane, which increases the space near the flame tube head. The inner and outer walls of the flame tube are perpendicular to the flame tube head plane. With the wall-mounted airflow, a symmetrically distributed recirculation zone can be formed that fills the vicinity of the flame tube head, which greatly increases the oil mist distribution range, which is beneficial to combustion chamber ignition and flame connection, and broadens the combustion chamber's operating envelope.

[0030] 10. The heat insulation screen of the present invention has a uniform wall thickness structure. The end face of the heat insulation screen facing the vortex generator is parallel to the end face of the flame tube head 7 facing the vortex generator, which can form a uniform cold air gap and avoid uneven cooling of the heat insulation screen. In addition, two radially elongated second protrusions are provided on the heat insulation screen, which can limit the circumferential flow of the cooling airflow on the back side and increase the air volume in the radial direction, allowing more head cold air to flow out from the position of the heat insulation screen near the inner and outer walls of the flame tube, thereby cooling the inner and outer walls of the flame tube.

[0031] 11. By arranging a first cooling hole, a second cooling hole, a third cooling hole, a fourth cooling hole and a fifth cooling hole at the head of the flame tube, the present invention can provide uniform cooling air to the heat insulation screen 6 and prevent high-temperature ablation.

[0032] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the 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 based on these drawings without creative effort.

[0034] Figure 1 A schematic diagram of the combustion chamber structure of an aviation gas turbine engine according to the prior art is shown; Figure 2 A schematic diagram of the structure of the anti-carbon deposit combined fuel atomizing device according to an embodiment of the present invention is shown; Figure 3 A schematic diagram of a fuel nozzle structure according to an embodiment of the present invention is shown; Figure 4 A top view of the outer casing according to an embodiment of the present invention is shown; Figure 5 It shows Figure 4 A sectional view of section AA in the middle; Figure 6 An isometric view of the outer casing according to an embodiment of the present invention is shown; Figure 7 A schematic diagram of the structure of an eddy current generator according to an embodiment of the present invention is shown; Figure 8 It shows Figure 7 Enlarged view of point C in the middle; Figure 9 A schematic diagram of the structure of a heat insulation screen according to an embodiment of the present invention is shown; Figure 10 A cross-sectional view of a heat insulation screen according to an embodiment of the present invention is shown; Figure 11 A gas flow distribution diagram on the back of a heat insulation screen according to an embodiment of the present invention is shown; Figure 12 A schematic diagram of the flame tube head structure according to an embodiment of the present invention is shown; Figure 13 It shows Figure 12 A sectional view of section DD in the middle; Figure 14 A diagram showing the distribution of cooling holes on the head of the flame tube according to an embodiment of the present invention is shown; Figure 15 A diagram showing the internal gas flow of an anti-carbon deposit combined fuel atomizing device according to an embodiment of the present invention is provided.

[0035] In the diagram: 1. Outer combustion chamber casing; 2. Inner combustion chamber casing; 3. Flame tube; 4. Fuel nozzle; 5. Swirler; 6. Heat shield; 7. Flame tube head; 41. Nozzle body; 411. Main fuel passage; 412. Auxiliary fuel passage; 42. Main nozzle; 43. Auxiliary nozzle; 44. Outer cover; 441. Third channel; 442. First air inlet; 443. Recessed platform; 444. First internal threaded hole; 445. Air outlet; 51. First-stage swirler; 52. Second-stage swirler; 53. Annular cover plate; 54. Movement clearance; 511. Inclined surface; 512. Second air inlet; 521. Venturi tube; 522. Guide ring; 523. Blade; 5211. 5212, First straight segment; 5221, Arc segment; 5222, Second straight segment; 5223, First pointed boss; 5224, Second pointed boss; 5225, Second external thread; 61, First boss; 62, Second internal thread hole; 63, Second boss; 71, Mounting hole; 72, Mounting edge; 73, Third boss; 74, First cooling hole; 75, Second cooling hole; 76, Third cooling hole; 77, Fourth cooling hole; 78, Fifth cooling hole; 100, Carbon blowing gas; 200, First-stage vortex inlet; 300, Second-stage vortex inlet; 400, Head cold air; 500, Two channels; 600, Symmetrical recirculation zone. Detailed Implementation

[0036] 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.

[0037] It should be noted that the terms "first," "second," etc., used in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," "longitudinal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings.

[0038] This invention provides a combined fuel atomization device for preventing carbon buildup. The device features a matching design for related components such as the fuel nozzle, swirl generator, and flame tube head, which work together to enhance atomization, expand the fuel mist distribution range, improve the combustion chamber ignition and flame connection capability, and improve the combustion chamber temperature field. This significantly reduces the risk of carbon buildup on the nozzle and flame tube head, and provides good stability, thus broadening the engine's operating envelope.

[0039] First, a brief explanation of the combustion chamber structure will be given, such as... Figure 2 As shown, the combustion chamber includes an outer combustion chamber casing 1, an inner combustion chamber casing 2, and a flame tube 3. The inner combustion chamber casing 2 is disposed inside the outer combustion chamber casing 1, and there is an annular cavity between the outer combustion chamber casing 1 and the inner combustion chamber casing 2. The flame tube 3 is disposed inside the annular cavity.

[0040] like Figure 2 As shown, an embodiment of the present invention provides a combined fuel atomizing device for preventing carbon buildup, including a fuel nozzle 4, a vortex generator 5, a heat shield 6, and a flame tube head 7.

[0041] One end of the fuel nozzle 4 is fixedly connected to the outer casing 1 of the combustion chamber. The flame tube head 7 is fixedly installed at the end of the flame tube 3 near the fuel nozzle 4. The heat shield 6 is connected to the flame tube head 7. The vortex generator 5 is detachably connected to the heat shield 6. For example, the vortex generator 5 and the heat shield 6 are connected by threads. After tightening, the two are clamped at the end near the fuel nozzle 4. The other end of the fuel nozzle 4 is inserted into the inside of the vortex generator 5.

[0042] like Figure 3 As shown, for example, the fuel nozzle 4 includes a nozzle body 41, which is provided with a main oil passage 411 and an auxiliary oil passage 412. Under low operating conditions in the combustion chamber, only the auxiliary oil passage 412 works. Under high operating conditions, both oil passages work simultaneously, ensuring the nozzle atomization quality under different operating conditions.

[0043] One end of the nozzle body 41 is fixedly connected to the outer casing 1 of the combustion chamber. The other end of the nozzle body 41 is provided with a main nozzle 42 and an auxiliary nozzle 43. The main nozzle 42 is sleeved on the outside of the auxiliary nozzle 43 to form an integral part. The auxiliary nozzle 43 has a first channel connected to the auxiliary oil passage 412 along the axial direction. There is a second channel between the inner wall of the main nozzle 42 and the auxiliary nozzle 43. The second channel is connected to the main oil passage 411. The auxiliary nozzle 43 is used to atomize the fuel in the auxiliary oil passage 412 and form a suitable mist cone. The main nozzle 42 is used to atomize the fuel in the main oil passage 411 and generate a suitable mist cone.

[0044] like Figure 3 and Figure 4 As shown, for example, the fuel nozzle 4 also includes an outer cover 44, which is sleeved on the outside of the main nozzle 42 and detachably connected to the outside of the nozzle body 41. The outer cover 44 presses and fixes the main nozzle 42 and the auxiliary nozzle 43 on the nozzle body 41. For example, the first internal thread hole 444 of the outer cover 44 is connected to the first external thread on the outer wall surface of the nozzle body 41.

[0045] like Figure 3 As shown, a third channel 441 is formed between the inner wall of the outer cover 44 and the outer wall of the main nozzle 42. The third channel 441 includes an annular section between the inner wall of the outer cover 44 and the outer wall of the main nozzle 42, and a conical section near the outlet of the main nozzle 42. The third channel 441 is a channel for the flow of carbon gas 100.

[0046] like Figure 5 and Figure 6 As shown, for example, a plurality of first air inlets 442 are provided circumferentially inside the wall of the outer cover 44. For example, the first air inlets 442 are circular, and there are 8 first air inlets 442. The 8 first air inlets 442 are evenly distributed circumferentially along the wall of the outer cover 44. The first air inlets 442 extend radially along the wall of the outer cover 44, and the axis of the first air inlets 442 forms an acute angle with the axial center line of the outer cover 44.

[0047] In this embodiment of the invention, a carbon-depositing gas 100 flow channel is formed between the outer cover 44 and the main nozzle 42, so that a uniform carbon-depositing gas 100 is formed at the outlet of the main nozzle 42, which can prevent carbon deposits at the outlet of the main nozzle 42. The airflow converges from the annular section of the third channel 441 to the conical section of the nozzle outlet, which can limit the oil mist cone angle of the main nozzle 42 to a certain extent, prevent excessive fuel from being injected onto the venturi tube 521 of the vortex generator 5, and reduce carbon deposits on the venturi tube 521.

[0048] For example, the area ratio of the conical section of the first air inlet 442 to the conical section of the third channel 441 is 1.4 to 1.5. The tapered structure can accelerate the blowing of carbon gas 100. The size of the conical section is controlled between 0.4 and 0.5 mm, which can prevent the amount of carbon gas 100 from being too large, and at the same time prevent the fuel splashed in the venturi tube 521 from entering the carbon blowing structure under extreme working conditions.

[0049] like Figure 5 and Figure 6 As shown, the outer wall of the outer cover 44 is provided with a recessed platform 443 at the inlet of each first air inlet 442. For example, the recessed platform 443 is strip-shaped. The outlet of each first air inlet 442 is connected to the third channel 441. The carbon-deposited gas 100 enters the third channel 441 formed by the inner wall of the outer cover 44 and the outer wall of the main nozzle 42 from the first air inlet 442, and finally flows out from the air outlet 445 of the outer cover 44. This serves to blow away carbon deposits at the nozzle and compress the fuel mist cone angle. The long strip-shaped recessed platform 443 at the inlet of the first air inlet 442 prevents the first air inlet 442 from being blocked by the edge of the vortex 5 after the fuel nozzle 4 is inserted into the vortex 5. The third channel 441 is also used to throttle the carbon-deposited gas 100.

[0050] like Figure 7 As shown, for example, the vortex generator 5 includes a primary vortex generator 51, a secondary vortex generator 52, and an annular cover plate 53. The secondary vortex generator 52 is detachably connected to the heat insulation screen 6. For example, the end of the secondary vortex generator 52 near the heat insulation screen 6 is threadedly connected to the heat insulation screen 6. The annular cover plate 53 is fixedly connected to the end face of the secondary vortex generator 52 away from the heat insulation screen 6, forming a movable gap 54. For example, the annular cover plate 53 can be welded to the secondary vortex generator 52. The annular cover plate 53 presses the primary vortex generator 51 onto the end face of the secondary vortex generator 52 away from the heat insulation screen 6. The primary vortex generator 51 can move radially in the movable gap 54.

[0051] The first-stage vortex generator 51 has a first receiving cavity arranged axially inside, and the outer cover 44 of the fuel nozzle 4 is inserted into the first receiving cavity. The inner wall of the first receiving cavity is provided with an inclined surface 511 near the end of the fuel nozzle 4.

[0052] In this embodiment of the invention, the outer wall of the outer cover 44 is provided with a strip-shaped recess 443 at the inlet of each first air inlet 442, and the inner wall of the first receiving cavity of the first stage vortex 51 is provided with a slope 511 at the end near the fuel nozzle 4 to prevent the first air inlet 442 from being blocked by the edge of the vortex 5 due to the expansion of the parts under hot conditions.

[0053] like Figure 7As shown, the outer wall of the first-stage vortex generator 51 is provided with a cylindrical section and a conical section in sequence along the direction close to the second-stage vortex generator 52. The conical section of the first-stage vortex generator 51 is provided with a plurality of second air inlets 512 in the circumferential direction. The second air inlets 512 extend radially along the wall of the conical section. Each second air inlet 512 is connected to the first receiving cavity. The axis of the second air inlet 512 forms an acute angle with the axial center line of the first-stage vortex generator 51. For example, there are 8 second air inlets 512, and the 8 second air inlets 512 are evenly distributed in the circumferential direction along the conical section of the first-stage vortex generator 51.

[0054] For example, the area ratio of the second air inlet 512 of the first-stage vortex generator 51 to the annular section of the third channel 441 of the carbon-depositing structure is 4.8 to 4.9, which ensures that the outlet air volume and flow rate of the venturi tube 521 can prevent high-temperature combustion gas from flowing back into the venturi tube 521 and causing carbon deposits on the fuel nozzle 4. At the same time, it also avoids that the outlet air volume and flow rate of the venturi tube 521 are too large, which would impact and damage the downstream flow field of the flame tube head 7.

[0055] The secondary vortex generator 52 includes a venturi tube 521, a guide ring 522, and blades 523. The venturi tube 521 has a flange at its end near the primary vortex generator 51. The side of the flange facing the primary vortex generator 51 is fixedly connected to an annular cover plate 53. The guide ring 522 is fitted onto the end of the venturi tube 521 away from the primary vortex generator 51. A first gap exists between the end face of the guide ring 522 near the primary vortex generator 51 and the side of the flange facing away from the primary vortex generator 51. A second gap exists between the inner wall of the guide ring 522 and the outer wall of the venturi tube 521. The first and second gaps are interconnected to form a fourth channel. Multiple blades 523 are disposed within the first gap and are evenly distributed circumferentially along the guide ring 522. Each blade 523 extends along the guide ring 522, and both axial sides of each blade 523 are fixedly connected to the end face of the guide ring 522 near the primary vortex generator 51 and the side of the flange facing away from the primary vortex generator 51, respectively.

[0056] For example, the inner cavity of the Venturi tube 521 is connected to the first receiving cavity. The inner cavity of the Venturi tube 521 includes a contraction section 5211, a first straight section 5212 and an expansion section arranged sequentially along the gas flow direction. For example, the roughness of the inner and outer wall surfaces of the Venturi tube 521 is less than Ra1.6, which can reduce carbon deposits.

[0057] The outlet of the fourth channel is connected to the outlet of the Venturi tube 521. The outlet of the guide ring 522 is the outlet of the vortex generator 5. The outlet of the guide ring 522 is flared, and the outlet angle α of the guide ring 522 is not less than 120°. The end face of the guide ring 522 is slightly higher than the wall of the heat insulation screen 6, ensuring that the airflow at the outlet of the vortex generator 5 can flow along the wall of the heat insulation screen 6, but will not excessively scour the wall. This increases the coverage area of ​​the recirculation zone of the flame tube head 7 while reducing the carbon area on the wall of the heat insulation screen 6.

[0058] like Figure 8 As shown, the inner wall cross-section of the guide ring 522 is provided with an arc segment 5221 and a straight segment 5222 in sequence along the gas flow direction at the outlet of the venturi tube 521. The radius of the arc segment 5221 gradually increases along the gas flow direction, so that the outlet of the secondary vortex 52 is in a large-angle flared shape, which can guide the outlet airflow to flow along the wall.

[0059] like Figure 8 As shown, for example, the arc segment 5221 is also provided with a first pointed protrusion 5223 and a second pointed protrusion 5224, which can increase the airflow disturbance on the wall and prevent a large amount of fuel from adhering to the outlet wall of the vortex generator 5 to form carbon deposits. The profile between the first pointed protrusion 5223 and the second pointed protrusion 5224 is consistent with the arc segment 5221 to avoid gas wall separation.

[0060] In this embodiment of the invention, the spray cone angle after the nozzle and the vortex generator 5 are matched does not exceed 80°. This ensures that the edge of the spray cone is near the intersection point B of the contraction section 5211 and the first straight section 5212 of the venturi tube 521, thus avoiding vertical impact of fuel on the wall of the contraction section 5211 of the venturi tube 521, reducing fuel splashing inside the venturi tube 521, and also preventing fuel from flowing back along the venturi tube 521. This reduces fuel accumulation and carbon buildup at the nozzle, the first-stage vortex generator 51, and the inner wall of the venturi tube 521.

[0061] like Figure 9 As shown, for example, the wall of the heat shield 6 is a thin-walled structure with uniform wall thickness. The shape of the heat shield 6 matches the flame tube head 7, which can isolate the high-temperature gas from the flame tube head 7 and prevent the head from being burned. There is a gap between the side of the heat shield 6 facing the flame tube head 7 and the flame tube head 7 to provide a channel for cooling gas.

[0062] like Figure 12 As shown, the flame tube head 7 is provided with mounting holes 71, such as... Figure 10 As shown, the heat insulation screen 6 is provided with an annular first protrusion 61, which is clearance-fitted with the mounting hole 71. The heat insulation screen 6 is also provided with a second internal threaded hole 62 that penetrates the first protrusion 61. The outer wall of the flow guide ring 522 is provided with a second external thread 5225, which is threadedly connected to the second internal threaded hole 62 of the heat insulation screen 6, thereby realizing the fixed connection between the vortex generator 5 and the heat insulation screen 6.

[0063] Two elongated second protrusions 63 are provided on the side of the heat shield 6 facing the flame tube head 7. The two second protrusions 63 are located on both sides of the second internal thread hole 62. Each second protrusion 63 extends radially along the heat shield 6. The second protrusions 63 are used to restrict the direction of cooling airflow. The flow distribution of cold air on the side of the wall facing the flame tube head 7 is shown in the attached figure. Figure 11 As shown.

[0064] In this embodiment of the invention, the heat insulation screen 6 has a uniform wall thickness structure. The end face of the heat insulation screen 6 facing the vortex generator 5 is parallel to the end face of the flame tube head 7 facing the vortex generator 5, which can form a uniform cold air gap and avoid uneven cooling of the heat insulation screen 6. In addition, the heat insulation screen 6 is provided with two radially elongated second protrusions 63, which can limit the circumferential flow of the cooling airflow on the back side and increase the air volume in the radial direction, allowing more head cold air 400 to flow out from the position of the heat insulation screen 6 near the inner and outer walls of the flame tube 3, thereby cooling the inner and outer walls of the flame tube 3.

[0065] like Figure 12 As shown, for example, the flame tube head 7 is annular and flat, and an installation edge 72 is provided on the outer side of the flame tube head 7. The installation edge 72 is fixedly connected to one end of the flame tube 3 near the fuel nozzle 4. For example, the end face of the installation edge 72 is connected to the outer wall of the flame tube 3, and the inner side of the installation edge 72 is also connected to the inner wall of the flame tube 3 by welding.

[0066] In this embodiment of the invention, the flame tube head 7 is an annular plane, which increases the space near the flame tube head 7. The inner and outer walls of the flame tube 3 are perpendicular to the plane of the flame tube head 7. With the wall-mounted airflow, a symmetrical recirculation zone 600 that fills the vicinity of the flame tube head 7 can be formed, which greatly increases the oil mist distribution range, which is beneficial to combustion chamber ignition and flame connection, and widens the combustion chamber's operating envelope.

[0067] like Figure 13 As shown, for example, the flame tube head 7 has multiple third protrusions 73 arranged circumferentially on the inner side of the mounting edge 72. The third protrusions 73 are annular, and each third protrusion 73 has a through mounting hole 71. For example, the mounting hole 71 is circular. There are 14 third protrusions 73, which are evenly distributed circumferentially along the flame tube head 7. Each third protrusion 73 has a through mounting hole 71. The mounting hole 71 is used to install the vortex generator 5 and the heat shield 6.

[0068] like Figure 14 As shown, for example, the surface of the flame tube head 7 is also provided with a first cooling hole 74, a second cooling hole 75, a third cooling hole 76, a fourth cooling hole 77 and a fifth cooling hole 78.

[0069] Each third protrusion 73 is provided with multiple first cooling holes 74, which are arranged in a ring array. The center point of the ring array is the center of the third protrusion 73, and the direction of the ring array is the circumference of the third protrusion 73. The diameter of the first cooling holes 74 is 0.9~1.0mm.

[0070] Each third boss 73 has multiple second cooling holes 75 on its outer side. The multiple second cooling holes 75 are arranged in a ring array. The center point of the ring array is the center of the third boss 73, and the direction of the ring array is the circumference of the third boss 73. The diameter of the second cooling hole 74 is 1.1~1.2mm.

[0071] The flame tube head 7 is symmetrically provided with multiple sets of third cooling holes 76 on both sides of each third protrusion 73. Adjacent sets of third cooling holes 76 are distributed circumferentially along the flame tube head 7. Each set of third cooling holes 76 includes multiple third cooling holes 76 distributed radially along the flame tube head 7. The diameter of the third cooling holes 76 is 0.9~1.0mm.

[0072] The flame tube head 7 has a plurality of fourth cooling holes 77 spaced circumferentially along its outer edge near the mounting edge 72. The plurality of fourth cooling holes 77 can be evenly distributed. For example, the diameter of the fourth cooling holes 77 is 1.2~1.3mm. The flame tube head 7 has a plurality of fifth cooling holes 78 spaced circumferentially along its inner edge away from the mounting edge 72. The plurality of fifth cooling holes 78 can be evenly distributed. For example, the diameter of the fifth cooling holes 78 is 1.2~1.4mm.

[0073] In this embodiment of the invention, by arranging a first cooling hole 74, a second cooling hole 75, a third cooling hole 76, a fourth cooling hole 77, and a fifth cooling hole 78 at the head 7 of the flame tube, uniform cooling air can be provided to the heat insulation screen 6 to prevent high-temperature ablation.

[0074] The anti-carbon-deposit combined fuel atomization device of this invention exhibits excellent atomization quality under all operating conditions, eliminating the problem of deteriorated nozzle backfire carbon deposit temperature field under extreme intake conditions. It achieves reliable ignition and flame connection at an altitude of 9 km and in extremely cold conditions of -45°C, and a lean-fuel flameout margin of 79.8% at 12 km airspeed. The reliable operating intake temperature of the combustion chamber is increased from 680K to 750K, effectively broadening the reliable operating envelope of the combustion chamber. This invention can provide guidance for the design of fuel atomization devices in the combustion chambers of aero-gas turbine engines.

[0075] The anti-carbon deposit combined fuel atomization device of this invention has been tested and verified by combustion chamber components. It has good fuel atomization, good ignition performance, and a large working envelope, and has a good anti-carbon deposit effect. Multiple tests have verified that the device has a reliable and stable structure.

[0076] like Figure 15As shown, the anti-carbon deposit combined fuel atomizing device of this embodiment can generate a large amount of wall-adhering airflow in the two channels 500 between the flame tube head 7, the outer combustion chamber 1, and the inner combustion chamber 2. The first-stage vortex inlet 200 enters from the second inlet 512, and the second-stage vortex inlet 300 enters from the inlet of the fourth channel, passes through the blades 523, and flows out from the outlet of the guide ring 522, forming a symmetrical recirculation zone 600 that fills the flame tube head 7 and the adjacent area, so that the flame tube head 7 is well atomized, the oil mist is evenly distributed over a wide range, which is convenient for ignition and flame connection, and at the same time, the combustion is more complete and the temperature field is more uniform.

[0077] The anti-carbon deposit combined fuel atomizing device of this invention has a reliable anti-carbon deposit function. The head of the fuel nozzle 4 is provided with a carbon-blowing structure that can form a carbon-blowing gas 100 to prevent carbon deposits from forming on the head of the fuel nozzle 4. The carbon-blowing gas 100 and the air intake 200 from the first-stage vortex generator form a matching airflow generated in the venturi tube 521, which can prevent the flow field at the outlet of the vortex generator 5 from flowing back and avoid high-temperature gas from entering the venturi tube 521 and aggravating carbon deposits on the nozzle head.

[0078] Compared with existing combustion chamber atomizing devices, the anti-carbon deposit combined fuel atomizing device of the present invention achieves better anti-carbon deposit effect through the mutual matching between various parts, while also having better ignition performance, and features a large working envelope and stable and reliable operation.

[0079] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A carbon deposit preventing combined fuel oil atomizing device characterized by comprising: The fuel nozzle (4), the vortex finder (5), the heat shield (6) and the flame tube head (7) are included. The fuel nozzle (4) is fixedly connected with the combustion chamber outer casing (1) at one end, the flame tube head (7) is fixedly arranged at one end of the flame tube (3) close to the fuel nozzle (4), the heat shield (6) is connected with the flame tube head (7), the vortex finder (5) is detachably connected with the heat shield (6), and the other end of the fuel nozzle (4) is inserted into the vortex finder (5). The fuel nozzle (4) includes a nozzle body (41) and an outer cover (44), one end of the nozzle body (41) is fixedly connected with the combustion chamber outer casing (1), the other end of the nozzle body (41) is provided with a main nozzle (42) and a secondary nozzle (43), the main nozzle (42) is sleeved outside the secondary nozzle (43), the outer cover (44) is sleeved outside the main nozzle (42) and is detachably connected with the outer side of the nozzle body (41), the outer cover (44) press-fits and fixes the main nozzle (42) and the secondary nozzle (43) on the nozzle body (41), a third channel (441) is formed between the inner wall of the outer cover (44) and the outer wall of the main nozzle (42), a plurality of first air inlet holes (442) are arranged in the circumferential direction in the inner wall of the outer cover (44), the outlet of each first air inlet hole (442) is communicated with the third channel (441), and the coke blowing gas (100) enters from the first air inlet hole (442).

2. The anti-carbon-deposition combined fuel atomizing device according to claim 1, characterized by The first air inlet hole (442) extends radially along the wall body of the outer cover (44), and the axis of the first air inlet hole (442) forms an acute angle with the axial center line of the outer cover (44).

3. The anti-carbon-deposition combined fuel atomizing device according to claim 1, characterized by The nozzle body (41) is provided with a main oil way (411) and a secondary oil way (412), the secondary nozzle (43) is provided with a first channel communicated with the secondary oil way (412) in the axial direction, and the inner wall of the main nozzle (42) and the secondary nozzle (43) have a second channel communicated with the main oil way (411).

4. The carbon deposit preventing combined fuel atomizing device according to claim 1, wherein The third channel (441) includes an annular segment between the inner wall of the outer cover (44) and the outer wall of the main nozzle (42) and a tapered segment close to the outlet of the main nozzle (42).

5. The carbon deposit preventing combined fuel atomizing device according to claim 1, wherein The area ratio of the first air inlet hole (442) to the tapered segment of the third channel (441) is 1.4-1.

5.

6. The carbon deposit preventing combined fuel atomizing device according to claim 1, wherein The vortex finder (5) includes a primary vortex finder (51), a secondary vortex finder (52) and an annular cover plate (53). The secondary vortex finder (52) is detachably connected with the heat shield (6), the annular cover plate (53) is fixedly connected with the end face of the secondary vortex finder (52) away from the heat shield (6) and forms an active gap (54), the annular cover plate (53) press-fits the primary vortex finder (51) on the end face of the secondary vortex finder (52) away from the heat shield (6), and the primary vortex finder (51) can move radially in the active gap (54). The first-stage vortex device (51) is internally provided with a first accommodating cavity in the axial direction, the outer cover (44) is inserted into the first accommodating cavity, and an inner wall of the first accommodating cavity is provided with an inclined surface (511) close to one end of the fuel nozzle (4), and an outer wall of the outer cover (44) is provided with a sunken platform (443) at the inlet of each first air inlet hole (442).

7. The carbon deposit preventing combined fuel atomizing device according to claim 6, wherein The outer wall of the first-stage vortex device (51) is sequentially provided with a cylindrical section and a conical section in the direction close to the second-stage vortex device (52), the conical section of the first-stage vortex device (51) is circumferentially provided with a plurality of second air inlet holes (512), the second air inlet holes (512) extend radially along the wall of the conical section of the first-stage vortex device (51), each second air inlet hole (512) is in communication with the first accommodating cavity, and the axis of the second air inlet hole (512) forms an acute angle with the axial center line of the first-stage vortex device (51).

8. The carbon deposit preventing combined fuel atomizing device according to claim 7, wherein The area ratio of the second air inlet hole (512) to the annular section of the third channel (441) is 4.8-4.

9.

9. The carbon deposit preventing combined fuel atomizing device according to claim 6, wherein The second-stage vortex device (52) comprises a venturi (521), a flow guide ring (522) and a blade (523). The flange portion is fixedly connected to the side surface of the first-stage vortex device (51) in the direction away from the first-stage vortex device (51), the flow guide ring (522) is sleeved on the end of the venturi (521) away from the first-stage vortex device (51), the end surface of the flow guide ring (522) close to the first-stage vortex device (51) and the side surface of the flange portion away from the first-stage vortex device (51) have a first gap, and the inner wall of the flow guide ring (522) and the outer wall of the venturi (521) have a second gap, the first gap and the second gap are in communication to form a fourth channel. A plurality of blades (523) are arranged in the first gap and are circumferentially distributed along the flow guide ring (522), each blade (523) extends along the flow guide ring (522), and the two sides of each blade (523) in the axial direction are fixedly connected to the end surface of the flow guide ring (522) close to the first-stage vortex device (51) and the side surface of the flange portion away from the first-stage vortex device (51) respectively. The inner cavity of the venturi (521) is in communication with the first accommodating cavity, the inner cavity of the venturi (521) comprises a converging section (5211), a first straight section (5212) and a diverging section which are sequentially arranged in the direction of gas flow, the outlet of the fourth channel is in communication with the outlet of the venturi (521), and the outlet of the flow guide ring (522) is in the form of an expanded opening.

10. The carbon deposit preventing combined fuel atomizing device according to claim 9, wherein The opening angle α of the outlet of the flow guide ring (522) is not less than 120°, and the end surface of the flow guide ring (522) is flush with the wall surface of the heat shield (6).

11. The carbon deposit preventing combined fuel atomizing device according to claim 9, wherein The inner wall cross section of the flow guide ring (522) is sequentially provided with a circular arc segment (5221) and a second straight line segment (5222) along the gas flow direction at the outlet of the venturi (521), wherein the radius of the circular arc segment (5221) gradually increases along the inner diameter in the gas flow direction.

12. The anti-carbon-deposition combination fuel atomizing device according to claim 11, characterized by The circular arc segment (5221) is also provided with a first pointed boss (5223) and a second pointed boss (5224), and the profile between the first pointed boss (5223) and the second pointed boss (5224) is the same as the circular arc segment (5221).

13. The anti-carbon-deposition combination fuel atomizing device according to any one of claims 9 to 11, characterized by The wall surface of the heat shield (6) is an equal wall thickness structure, the shape of the heat shield (6) matches the flame tube head (7), and there is a gap between the side surface of the heat shield (6) facing the flame tube head (7) and the flame tube head (7); The flame tube head (7) is provided with a mounting hole (71), the heat shield (6) is provided with a first boss (61), the first boss (61) is in clearance fit with the mounting hole (71), the heat shield (6) is also provided with a second internal thread hole (62) penetrating the first boss (61), the outer wall of the flow guide ring (522) is provided with a second external thread (5225), the second external thread (5225) is in threaded connection with the second internal thread hole (62); the wall surface of the heat shield (6) is provided with two second bosses (63) on the side surface facing the flame tube head (7), and the two second bosses (63) are respectively located on the two sides of the second internal thread hole (62), and each second boss (63) extends radially along the heat shield (6).

14. The carbon deposit preventing combined fuel atomizing device according to claim 1, wherein The flame tube head (7) is annular and flat, the outer side of the flame tube head (7) is provided with a mounting edge (72), the mounting edge (72) is fixedly connected with the end of the flame tube (3) close to the fuel nozzle (4), and a plurality of third bosses (73) are arranged on the inner side of the mounting edge (72) in a circumferential direction, and each third boss (73) is provided with a mounting hole (71) penetrating therethrough.

15. The anti-carbon-deposition combination fuel atomizing device according to claim 14, characterized by The surface of the flame tube head (7) is also provided with a first cooling hole (74), a second cooling hole (75), a third cooling hole (76), a fourth cooling hole (77) and a fifth cooling hole (78). Each third boss (73) is provided with a plurality of first cooling holes (74), and the plurality of first cooling holes (74) are arranged in an annular array, the center point of the annular array is the center of the third boss (73), and the direction of the annular array is the circumferential direction of the third boss (73). The outer side of each third boss (73) is provided with a plurality of second cooling holes (75), and the plurality of second cooling holes (75) are arranged in an annular array, the center point of the annular array is the center of the third boss (73), and the direction of the annular array is the circumferential direction of the third boss (73). The flame tube head (7) is symmetrically provided with a plurality of groups of third cooling holes (76) on both sides of each third boss (73), and adjacent two groups of third cooling holes (76) are distributed along the circumference of the flame tube head (7) at intervals, and each group of third cooling holes (76) comprises a plurality of third cooling holes (76) distributed along the radial direction of the flame tube head (7); The flame tube head (7) is symmetrically provided with a plurality of groups of third cooling holes (76) on both sides of each third boss (73), and adjacent two groups of third cooling holes (76) are distributed along the circumference of the flame tube head (7) at intervals, and each group of third cooling holes (76) comprises a plurality of third cooling holes (76) distributed along the radial direction of the flame tube head (7); The flame tube head (7) is symmetrically provided with a plurality of groups of third cooling holes (76) on both sides of each third boss (73), and adjacent two groups of third cooling holes (76) are distributed along the circumference of the flame tube head (7) at intervals, and each group of third cooling holes (76) comprises a plurality of third cooling holes (76) distributed along the radial direction of the flame tube head (7);

Images