A composite anti-icing structure for jet pre-cooling device

Abstract

The present application belongs to an air-breathing combined cycle engine in the field of aviation hyperpower, and particularly relates to a composite anti-icing structure for a jet pre-cooling device; it includes an air supply structure and a heat transfer structure; the air supply structure has an air supply channel, the heat transfer structure has an outer wall and an inner wall, the inner wall forms an inner heat transfer channel extending from the top to the root of the heat transfer structure, and an outer heat transfer channel extending from the top to the root of the heat transfer structure is formed between the outer wall and the inner wall, the inner wall has an inner through hole connecting the inner heat transfer channel and the outer heat transfer channel, the outer wall has an outer through hole connecting the outer heat transfer channel and the outside, and the inner heat transfer channel and the outer heat transfer channel are both connected to the air supply channel. The present application can make full use of hot air energy, reasonably adjust energy distribution, and ensure that water impact areas can be covered by anti-icing protection. At the same time, due to the effect of blowing away overflow water droplets through the air film seam, icing can be reduced in areas without hot air protection.

Description

Technical Field

[0001] The present application relates to an air-breathing combined cycle engine in the field of aviation hyperpower, and in particular to a composite anti-icing structure for a jet pre-cooling device. Background Art

[0002] Because different types of engines have their own performance advantages across different flight ranges, many countries around the world have explored combining the strengths of different engine types within each mission segment to form a combined cycle engine. Within the development of air-breathing combined cycle engines, pre-cooled TBCC engines based on turbine engines have shown promising development prospects. One pre-cooling solution involves adding a jet pre-cooler to the front of the inlet duct of a conventional turbine engine. A nozzle is positioned within the jet pre-cooler, spraying fluid into the inlet duct, evaporatively cooling the airflow therein, reducing its temperature and extending the turbine engine's operating range. Furthermore, at high Mach numbers, the inlet stagnation temperature increases, leading to a decrease in air density, reduced flow rate, and reduced engine thrust. Jet pre-cooling is essential to ensure efficient and stable operation of turbine engines over a wide range.

[0003] Since the jet precooling device is arranged in the air inlet, when the aircraft encounters icing weather conditions, air containing supercooled water droplets will enter the air inlet, and the supercooled water will hit the jet precooling device to produce ice. Ice will affect the aerodynamic shape of the jet precooling device, reduce the airflow area, and thus affect the engine performance; at the same time, the falling of accumulated ice may damage engine components, and in severe cases, affect the operating safety of the engine. In order to ensure the performance and safety of the engine, anti-icing measures need to be taken for the jet precooling device to ensure that it has an acceptable aerodynamic shape and prevent the formation of ice that endangers the safety of the engine. To this end, this patent proposes an anti-icing method and system for a jet precooling device, which provides anti-icing protection for the jet precooling device, effectively meeting the anti-icing needs of the engine while reducing energy consumption.

[0004] With the continuous improvement of aircraft engine performance, there is an increasing demand for anti-icing systems and methods that minimize hot gas temperature drop and air consumption while ensuring safe and stable all-weather engine operation. Because the jet precooling device is similar in appearance to the imported components of a turbofan engine, the prior art related to the present invention is a straightening strut hot gas anti-icing system. However, existing hot gas anti-icing systems have the following shortcomings in anti-icing applications:

[0005] 1. From a technical perspective: The existing hot gas anti-icing system needs to improve the utilization rate of the valuable anti-icing hot gas resources, and the anti-icing effect in key protection areas can be further enhanced;

[0006] 2. Efficiency: Existing hot gas anti-icing systems generally have low heat transfer efficiency, resulting in a large temperature drop along the hot gas path. This results in suboptimal anti-icing effects at the root section of the heat transfer structure.

[0007] 3. In terms of energy consumption: The existing hot gas anti-icing system has a large anti-icing hot gas flow rate, which consumes a lot of energy on the engine, thereby affecting engine performance. Summary of the Invention

[0008] In order to solve the above problems, the present application provides a composite anti-icing structure for a jet pre-cooling device, comprising:

[0009] The composite anti-icing structure is arranged on the upstream side of the jet pre-cooling device, and the composite anti-icing structure includes an air supply structure and a heat transfer structure;

[0010] An air supply structure having an air supply channel connected to the air compressor via an air supply pipe, the air supply pipe introducing high-temperature and high-pressure air from the compressor into the air supply structure;

[0011] The heat transfer structure has an outer wall and an inner wall, the inner wall forms an inner heat transfer channel extending from the top of the heat transfer structure to the root, and an outer heat transfer channel extending from the top of the heat transfer structure to the root is formed between the outer wall and the inner wall. The inner wall has an inner through hole connecting the inner heat transfer channel and the outer heat transfer channel, and the outer wall has an outer through hole connecting the outer heat transfer channel and the outside world. The inner heat transfer channel and the outer heat transfer channel are both connected to the air supply channel, wherein the outer wall is the front flow surface.

[0012] The technical effects of the above technical features are:

[0013] Preferably, the air supply channel includes an outer air supply channel and an inner air supply channel, the outer air supply channel is connected to the outer heat transfer channel, and the inner air supply channel is connected to the inner heat transfer channel.

[0014] Preferably, the outer air supply channel and the inner air supply channel are respectively connected to an air supply pipe, and each air supply pipe is equipped with a flow valve.

[0015] Preferably, the inner through hole is located on the inner wall near the root.

[0016] Preferably, the heat transfer structure is a symmetrical structure with equal cross-sections, and the outer wall and the inner wall bulge toward the incoming flow direction at the symmetry plane to form a streamlined curved surface.

[0017] Preferably, the inner through hole is located at the front end of the inner wall toward the incoming flow direction, the outer through hole is located at the rear end of the outer wall toward the incoming flow direction, the outer through holes are symmetrically distributed along the symmetry plane, and the outer through holes are evenly distributed from the top to the root.

[0018] Preferably, the volume of the inner heat exchange channel is greater than the volume of the outer heat exchange channel, and the surface area of ​​the inner heat exchange channel is smaller than the surface area of ​​the outer heat exchange channel.

[0019] Preferably, the outer through hole adopts a runway-shaped air film seam, the width of the air film seam is between 1 mm and 1.5 mm, and the length is between 18 mm and 22 mm.

[0020] Preferably, the distance between the inner wall and the outer wall is largest at the front end facing the incoming flow direction.

[0021] Preferably, the total flow area of ​​the inner through holes is 100 mm 2 ~120mm 2 .

[0022] The advantages of the present application include: 1. Based on the characteristics of the anti-icing system of the present invention, a dual-channel air supply structure is proposed, which can achieve the purpose of individually adjusting the air supply flow according to the set target; 2. The present invention adopts a composite anti-icing method of "hot air insulation layer" coupled with "convection + impact + air film", which can make full use of hot air energy, reasonably adjust energy distribution, and ensure that the water impact area can be covered by anti-icing protection. At the same time, due to the effect of blowing away overflow water droplets through the air film seam, ice formation can be reduced in areas without hot air protection; 3. The anti-icing system of the present invention has dual hot air channel characteristics, which can greatly reduce the temperature drop of hot air along the process, and ensure that the anti-icing effect of any position of the anti-icing component meets the anti-icing requirements; 4. The anti-icing system of the present invention has high heat transfer efficiency, and the anti-icing hot air flow used is small, which ensures the safe and stable operation of the turbine under all weather conditions, while minimizing the impact of anti-icing air on engine working efficiency, reducing engine energy consumption, and improving engine performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the installation of a jet pre-cooling device in an air inlet duct according to a preferred embodiment of the present application;

[0024] Figure 2 This is a schematic diagram of an axial perspective of a jet pre-cooling device installed in an air inlet duct according to a preferred embodiment of the present application;

[0025] Figure 3 This is a cross-sectional view of a composite anti-icing structure according to a preferred embodiment of the present application;

[0026] Figure 4 This is a schematic diagram of the air intake structure of a preferred embodiment of the present application;

[0027] Figure 5 yes Figure 4 EE cross-section of the air intake structure;

[0028] Figure 6 yes Figure 4 FF cross-section of the air intake structure;

[0029] Figure 7 yes Figure 4 Longitudinal cross-section of the air intake structure;

[0030] Figure 8 It is a transverse cross-sectional view of the jet pre-cooling device and the heat transfer structure;

[0031] Figure 9 It is a longitudinal cross-sectional view of the jet pre-cooling device and the heat transfer structure. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the implementation of this application will be described in more detail below in conjunction with the drawings in the implementation of this application. In the drawings, the same or similar numbers throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and should not be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in conjunction with the drawings.

[0033] The present application provides a composite anti-icing structure for a jet pre-cooling device, comprising:

[0034] The composite anti-icing structure is arranged on the upstream side of the jet pre-cooling device, and includes an air supply structure and a heat transfer structure; the air supply structure has an air supply channel, the air supply channel is connected to the compressor through an air supply pipe, and the air supply pipe introduces high-temperature and high-pressure air from the compressor into the air supply structure;

[0035] The heat transfer structure has an outer wall and an inner wall, the inner wall forms an inner heat transfer channel extending from the top of the heat transfer structure to the root, and an outer heat transfer channel extending from the top of the heat transfer structure to the root is formed between the outer wall and the inner wall. The inner wall has an inner through hole connecting the inner heat transfer channel and the outer heat transfer channel, and the outer wall has an outer through hole connecting the outer heat transfer channel and the outside world. The inner heat transfer channel and the outer heat transfer channel are both connected to the air supply channel, wherein the outer wall is the front flow surface.

[0036] The air supply channel includes an outer air supply channel and an inner air supply channel. The outer air supply channel is connected to the outer heat transfer channel, and the inner air supply channel is connected to the inner heat transfer channel.

[0037] The outer air supply channel and the inner air supply channel are respectively connected to an air supply pipe, and a flow valve is installed on each air supply pipe.

[0038] The outer through hole is located on the outer wall near the root.

[0039] The heat transfer structure is a symmetrical structure with equal cross-sections, and the outer wall and the inner wall are convex toward the incoming flow direction at the symmetry plane to form a streamlined curved surface.

[0040] The inner through holes are located at the front end of the inner wall toward the incoming flow direction, and the outer through holes are located at the rear end of the outer wall toward the incoming flow direction. The outer through holes are symmetrically distributed along the symmetry plane and are evenly distributed from the top to the root.

[0041] The volume of the inner heat exchange channel is greater than that of the outer heat exchange channel, and the surface area of ​​the inner heat exchange channel is smaller than that of the outer heat exchange channel.

[0042] The outer through hole adopts a runway-type air film seam, the width of the air film seam is between 1mm and 1.5mm, and the length is between 18mm and 22mm.

[0043] The distance between the inner wall and the outer wall is largest at the front end facing the incoming flow direction.

[0044] The total flow area of ​​the inner through hole is 100mm 2 ~120mm 2 ;

[0045] In order to increase the heat transfer coefficient and enhance the heat transfer effect between hot gas and the outer wall, and considering the convenience of processing in actual engineering, the width of the outer heat exchange channel is about 1mm to 3mm;

[0046] The following is a detailed description with reference to the accompanying drawings: Figure 1 Figure 2 As shown, the jet precooling device a is arranged inside the inlet duct of the turbine b. Figure 2 This figure shows the distribution of jet precooler a at the inlet duct. When turbine b operates at high Mach numbers, the inlet airflow stagnation temperature exceeds the allowable temperature of the material of turbine inlet component c. Lowering the inlet airflow temperature allows turbine b components to operate safely at high Mach numbers while also extending the operating range of turbine b. Based on this, multiple jet precoolers a can be installed at the inlet of turbine b. When turbine b operates at high Mach numbers, these jet precoolers a spray micro-droplets, which evaporate and remove heat from the airflow, thereby lowering the airflow temperature.

[0047] Since the jet precooling device a is arranged in the air inlet. When the aircraft encounters icing weather conditions, the airflow containing liquid supercooled water will enter the air inlet. The supercooled water will hit the jet precooling device a to produce ice, which will cause the engine inlet flow field to change. At the same time, the shedding of accumulated ice may also damage the engine components. Therefore, it is necessary to protect the jet precooling device a from ice. The present invention adopts a hot air anti-icing method. The principle is that the high-temperature and high-pressure air drawn out by the compressor d enters the anti-icing system of the jet precooling device, thereby ensuring that the jet precooling device can work stably within the icing envelope. The composite anti-icing structure of the present invention is arranged on the upstream side of the jet precooling device. The composite anti-icing structure as a whole is as follows. Figure 3 As shown, it includes an air supply structure 1 and a heat transfer structure 2; the air supply structure 1 has an air supply channel, which is connected to the compressor through an air supply pipe, and the air supply pipe introduces the high-temperature and high-pressure air of the compressor into the air supply structure 1;

[0048] The transverse cross-sectional view of the heat transfer structure 2 and the jet pre-cooling device a is shown in FIG. Figure 8 As shown, the longitudinal cross-sectional view of the heat transfer structure 2 and the jet pre-cooling device a is as shown in FIG. Figure 9 As shown, the heat transfer structure 2 has an outer wall and an inner wall, the inner wall forms an inner heat transfer channel 22 extending from the top to the root of the heat transfer structure 2, and an outer heat transfer channel 21 extending from the top to the root of the heat transfer structure 2 is formed between the outer wall and the inner wall, the inner wall has an inner through hole connecting the inner heat transfer channel 22 and the outer heat transfer channel 21, the inner through hole is the exhaust hole 23 in the figure, and the air film gap is the air film gap 24 in the figure, the outer wall has an outer through hole connecting the outer heat transfer channel 21 and the outside, the outer through hole is the air film gap 24 in the figure, the inner heat transfer channel 22 and the outer heat transfer channel 21 are both connected to the air supply channel, wherein the outer wall is the front flow surface.

[0049] The air supply channel includes an outer air supply channel 12 and an inner air supply channel 11. Figure 4-Figure 7As shown, the outer air supply channel 12 is connected to the outer heat transfer channel 21, and the inner air supply channel 11 is connected to the inner heat transfer channel 22. The outer air supply channel 12 and the inner air supply channel 11 are each connected to an air supply pipe, each of which is equipped with a flow valve. The flow valve can supply air to the inner heat transfer channel 22 and the outer heat transfer channel 21 of the jet precooling device's heat transfer structure separately, adjusting the flow rate as required. Hot air enters the heat transfer structure 2 within the jet precooling device a from the inner and outer air supply channels 11 and 12, respectively. This ensures that the two-channel air supply structure 1 is independent and does not interfere with each other. This air supply structure is made of flexible material, allowing the flow area of ​​the two air supply pipes to be flexibly adjusted according to different engine conditions, thereby adjusting the flow distribution. The air film seam 24 is located near the root of the outer wall. The heat transfer structure 2 is a symmetrical structure with equal cross-sections. The outer and inner walls bulge in the direction of the incoming flow at the plane of symmetry, forming a streamlined curved surface. The exhaust hole 23 is located at the front end of the inner wall toward the incoming flow direction, and the air film slit 24 is located at the rear end of the outer wall toward the incoming flow direction. The air film slit 24 is symmetrically distributed along the symmetry plane, and the air film slit 24 is evenly distributed from the top to the root. The air film slit 24 adopts a runway-type air film slit, and the width of the air film slit is between 1 and 1.5 mm, and the length is between 18 and 22 mm; the distance between the inner wall and the outer wall is the largest at the front end toward the incoming flow direction; the total flow area of ​​the exhaust hole 23 is 100 to 120 mm 2 .

[0050] During operation, a portion of the hot air flowing out of the air supply structure 1 enters the inner heat transfer channel 22 from the top of the inner air supply channel 11. The hot air flows from the top to the root, and then flows into the outer heat transfer channel 21 through the exhaust hole 23 at the root. The hot air discharged from the exhaust hole 23 impacts the wall surface at the front edge of the outer wall, with the purpose of enhancing the heat exchange between the hot air and the front edge of the outer wall and increasing the temperature of the outer wall; then it moves in two directions: one part moves toward the root of the outer heat transfer channel 21, converges in the same direction with the hot air in the outer heat transfer channel 21, and then is discharged through the air film slit 24 at the root; the other part flows to the middle of the outer heat transfer channel 21, impacting the hot air in the channel in the opposite direction, with the purpose of strengthening the turbulence in the middle and increasing the internal heat transfer coefficient. After mixing, it is discharged through the air film slit 24 in the lower middle part. Because the volume of the inner heat transfer channel is larger than that of the outer heat transfer channel, and the surface area of ​​the inner heat transfer channel is smaller than that of the outer heat transfer channel, the inner heat transfer channel 22 provides insulation for the hot air in the outer heat transfer channel 21, greatly reducing the temperature drop of the outer hot air along the process. Due to the existence of the root exhaust hole 23, the flow of hot air from the middle and lower part to the root is strengthened, the turbulence is strengthened, the heat transfer coefficient is increased, and the heat transfer at the root is enhanced; another part of the hot air flowing out of the air supply structure 1 enters the outer heat transfer channel 21 through the top air vent, and the hot air flows from the top to the root, heating the front edge and the side of the outer wall of the device in the form of convection. The heated hot air is discharged from the air film gap 24 at the rear edge of the outer heat transfer channel 21. At this time, the hot air flow rate is large and the temperature is high, which can form an air film protection on the outer wall surface to prevent the overflow water impacted by the front from flowing backward, making it less likely to form ice due to the overflow water in the non-heated area at the rear, further increasing the protection area.

[0051] In summary, the specific points of implementing the anti-icing device in this application include:

[0052] 1. Due to the presence of the inner heat transfer channel 22 and the outer heat transfer channel 21, the hot air can achieve a mutual insulation effect when flowing along the inside of the two channels, which can achieve the "hot air insulation" mentioned in the composite anti-icing method;

[0053] 2. The hot air in the outer heat transfer channel 21 heats the outer wall by "convection" heat exchange as it moves from the top to the root;

[0054] 3. The two exhaust holes 23 at the root between the inner and outer heat transfer channels allow the hot air from the inner heat transfer channel 22 to impact the leading edge of the outer wall at the root of the jet pre-cooling device 1, which has relatively weak anti-icing properties, thus achieving the "impact" mentioned in the composite anti-icing method.

[0055] 4. After heating the outer wall, the hot air is discharged from the air film gap 24 at the rear edge of the outer heat transfer channel 21. At this time, the hot air flow rate is large and the temperature is high, which can form an air film protection on the outer wall surface, realizing the "air film" mentioned in the composite anti-icing method.

[0056] This application has the following technical effects:

[0057] 1. It can achieve the purpose of adjusting the gas supply flow individually according to the set target;

[0058] 2. This application uses a composite anti-icing structure that combines a "hot air insulation layer" with "convection + impact + air film." This fully utilizes the hot air energy and rationally adjusts energy distribution to ensure that all water impact areas are covered by anti-icing protection. Furthermore, the air film seams remove overflowing water droplets, reducing ice formation in areas without hot air protection.

[0059] 3. The air supply structure of this application features dual hot gas channels, which can significantly reduce the temperature drop of hot gas along the way, ensuring that the anti-icing effect at any position of the anti-icing component meets the anti-icing requirements;

[0060] 4. The heat transfer structure of the present application has high heat transfer efficiency and uses a small anti-icing hot air flow rate, which ensures the safe and stable operation of the turbine in all weather conditions, while minimizing the impact of anti-icing air on the engine's operating efficiency, reducing engine energy consumption and improving engine performance.

[0061] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A composite anti-icing structure for a jet pre-cooling device, characterized in that: include: The composite anti-icing structure is arranged on the upstream side of the jet pre-cooling device, and the composite anti-icing structure includes an air supply structure and a heat transfer structure; An air supply structure having an air supply channel connected to the air compressor via an air supply pipe, the air supply pipe introducing high-temperature and high-pressure air from the compressor into the air supply structure; The heat transfer structure comprises an outer wall and an inner wall, wherein the inner wall forms an inner heat transfer channel extending from the top to the root of the heat transfer structure, and an outer heat transfer channel extending from the top to the root of the heat transfer structure is formed between the outer wall and the inner wall, the inner wall has an inner through hole connecting the inner heat transfer channel and the outer heat transfer channel, and the outer wall has an outer through hole connecting the outer heat transfer channel and the outside, and the inner heat transfer channel and the outer heat transfer channel are both connected to the air supply channel, wherein the outer wall is a flow-facing surface; and the inner through hole is located near the root of the inner wall; The air supply channel includes an outer air supply channel and an inner air supply channel. The outer air supply channel is connected to the outer heat transfer channel, and the inner air supply channel is connected to the inner heat transfer channel.

2. The composite anti-icing structure for a jet pre-cooling device according to claim 1, characterized in that: The outer air supply channel and the inner air supply channel are respectively connected to an air supply pipe, and a flow valve is installed on each air supply pipe.

3. The composite anti-icing structure for a jet pre-cooling device according to claim 1, characterized in that: The inner through hole is located on the inner wall near the root.

4. The composite anti-icing structure for a jet pre-cooling device according to claim 1, characterized in that: The heat transfer structure is a symmetrical structure with equal cross-sections, and the outer wall and the inner wall are convex toward the incoming flow direction at the symmetry plane to form a streamlined curved surface.

5. The composite anti-icing structure for a jet pre-cooling device according to claim 4, characterized in that: The inner through holes are located at the front end of the inner wall toward the incoming flow direction, and the outer through holes are located at the rear end of the outer wall toward the incoming flow direction. The outer through holes are symmetrically distributed along the symmetry plane and are evenly distributed from the top to the root.

6. The composite anti-icing structure for a jet pre-cooling device according to claim 1, characterized in that: The volume of the inner heat exchange channel is greater than that of the outer heat exchange channel, and the surface area of ​​the inner heat exchange channel is smaller than that of the outer heat exchange channel.

7. The composite anti-icing structure for a jet pre-cooling device according to claim 5, characterized in that: The outer through hole adopts a runway-type air film seam, the width of the air film seam is between 1mm and 1.5mm, and the length is between 18mm and 22mm.

8. The composite anti-icing structure for a jet pre-cooling device according to claim 4, characterized in that: The distance between the inner wall and the outer wall is largest at the front end facing the incoming flow direction.

9. The composite anti-icing structure for a jet pre-cooling device according to claim 4, characterized in that: The total flow area of ​​the inner through holes is 100 mm 2 ~120mm 2 .

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