Device for self-adaptively adjusting air inlet flow of prewhirl air supply system

Abstract

The invention relates to the technical field of prewhirl air supply of aero-engines, in particular to an air inlet flow self-adaptive adjusting device for a prewhirl air supply system, which comprises a plurality of air inlet guide components and an air inlet baffle plate, each air inlet guide assembly is connected with the front edge of a blade of the corresponding blade hole type pre-whirl nozzle, and an air inlet flow guide channel is formed in each air inlet guide assembly and communicates with a nozzle flow channel of the corresponding blade hole type pre-whirl nozzle; the air inlet baffle is rotationally arranged in the air inlet flow guide channel through a rotating shaft, a torsional spring used for providing pre-tightening force for the air inlet baffle is arranged on the rotating shaft, the air inlet baffle is perpendicular to the surface of the nozzle inner ring in the pre-tightening force state, and the air inlet baffle is driven to rotate through the differential pressure of air inlet pressure under different cruise working conditions and the pre-tightening force of the torsional spring. Therefore, the air inlet area entering the blade hole type pre-swirl nozzle is adjusted. The air entraining amount of the pre-whirl air supply system is adjusted in real time, and the operation efficiency of an engine is improved.

Description

Technical Field

[0001] The invention relates to the technical field of pre-swirl air supply for aircraft engines, and in particular to a device for adaptively regulating the intake air flow of a pre-swirl air supply system. Background Art

[0002] With the update and iteration of modern aviation technology, the progress and development of aviation engine technology plays a very critical role in the progress and development of aircraft. Aviation gas turbine engines are developing towards high thrust-to-weight ratio and low fuel consumption. It is generally believed that under the condition that the engine size remains unchanged, the gas temperature at the turbine inlet will increase by 55K for every 10% increase in thrust. The gas temperature before the turbine of some advanced aviation engines with a thrust-to-weight ratio of 15-20 has exceeded 2200K, and the temperature before the turbine continues to increase over time. Excessive turbine temperature poses a challenge to the safe and reliable operation of the engine. In response to this problem, scientific researchers started from the following two aspects: 1) Develop new high-temperature resistant materials to improve the temperature resistance limit of turbine rotor blades; 2) Use more advanced cooling technology to reduce the wall temperature of high-temperature components. According to relevant statistical data, the rate of increase in the temperature resistance limit of materials is far less than the rate of increase in the temperature before the turbine, which has led to the emergence of some advanced and efficient cooling technologies, and the pre-swirl air supply system is one of the representatives. The pre-swirl gas supply system has huge cooling potential. A pre-swirl gas supply system with better performance can achieve a cooling of 100K.

[0003] The cooling principle of the pre-swirl air supply system is to accelerate the airflow through the pre-swirl nozzle and form a larger circumferential velocity component, reduce the relative velocity between the static temperature of the airflow and the turntable, and thus achieve the purpose of reducing the relative total temperature of the airflow. From the perspective of cooling effect alone, the more cooling air is used, the better the effect. However, the cooling air drawn from the compressor will not work in the turbine, which will reduce the thrust generated by the engine. Therefore, the amount of air drawn from the pre-swirl air supply system will directly affect the performance of the whole machine. Studies have found that for every 1% increase in the amount of air drawn from the pre-swirl air supply system, the engine thrust is lost by about 2%. When the flight Mach number is less than 1.2, the fuel consumption rate increases by 0.7%~0.9%, and when it is higher than 1.2, the fuel consumption rate increases by 1.2%~1.4%. Taking the high bypass ratio turbofan engine as the research object, a turbine cooling algorithm that considers the amount of cooling air and the cooling incidental efficiency loss is introduced into the whole machine performance calculation model. It is found that if the amount of cooling air is reduced by 20%, the unit thrust of the engine can be increased by 3% and the fuel consumption rate can be reduced by 0.9%. Therefore, advanced aircraft engines require more pre-swirl air supply system intake flow at high cruise conditions, and less intake flow at low cruise conditions. This requires that the intake flow of the pre-swirl air supply system can be adjusted according to the cruise conditions.

[0004] In the prior art, the commonly used solution for controlling the amount of bleed air in the pre-swirl air supply system is to divide the nozzle flow path into a normally open flow path and an adjustable flow path. When the engine is running under high operating conditions, all flow paths are open to ensure the amount of cooling air for the turbine blades. When the engine is running under low operating conditions, the adjustable flow path can be closed to reduce the amount of cooling air. The traditional method is to install a valve at the last stage of the compressor, and actively adjust the bleed air valve at the last stage of the compressor according to the operating conditions of the engine to control the amount of bleed air in the pre-swirl air supply system. However, this method greatly increases the weight of the engine. The addition of an active control valve device at the last stage of the compressor not only makes assembly difficult, but also reduces the reliability of engine operation. Therefore, a more reliable autonomous adjustment method is needed. Therefore, it is necessary to provide a device for adaptively adjusting the intake air flow rate of a pre-swirl air supply system to solve the above-mentioned problem. Summary of the invention

[0005] The present invention provides a device for adaptively adjusting the intake flow of a pre-swirl air supply system. The device of the present invention can autonomously adjust the intake baffle according to different operating conditions of the engine (such as high cruise conditions and low cruise conditions) to adjust the bleed air volume of the pre-swirl air supply system, so that the pre-swirl air supply system can obtain a more appropriate bleed air volume under different operating conditions, so as to solve the existing problem of installing a valve at the end of the compressor and actively adjusting the bleed air valve at the end of the compressor according to the operating conditions of the engine to control the bleed air volume of the pre-swirl air supply system. However, this method greatly increases the weight of the engine, and adds an active control valve device at the end of the compressor, which not only makes assembly difficult, but also reduces the reliability of engine operation.

[0006] The present invention discloses a device for adaptively adjusting the intake air flow rate of a pre-swirl air supply system, which adopts the following technical scheme, including: A plurality of air intake guide assemblies are evenly arranged on the inner ring of the nozzle, and each air intake guide assembly is connected to the leading edge of a blade of a leaf hole type pre-swirl nozzle, an air intake guide channel is formed in the air intake guide assembly, and the air intake guide channel is connected to the nozzle flow channel of the corresponding leaf hole type pre-swirl nozzle; And an intake baffle is rotatably arranged in the intake guide channel through a rotating shaft, and a torsion spring is arranged on the rotating shaft to provide a pre-tightening force for the intake baffle. In the pre-tightening state, the intake baffle is perpendicular to the surface of the inner ring of the nozzle, and the intake baffle is driven to rotate by the difference pressure between the intake pressure under different cruising conditions and the pre-tightening force of the torsion spring to adjust the intake area entering the leaf hole type pre-swirl nozzle.

[0007] Preferably, the air intake guide assembly comprises: two leading edge plates, the leading edge plates are arranged on the outer peripheral surface of the nozzle inner ring, the ends of the leading edge plates are connected to the leading edges of the blades of the leaf hole type pre-swirl nozzle of the nozzle inner ring, and an air intake guide channel is formed between the two leading edge plates.

[0008] Preferably, two connecting ears are provided on the end face of the air intake baffle, the rotating shaft is passed through the two connecting ears, the torsion spring is sleeved on the rotating shaft between the two connecting ears, and one force-bearing end of the torsion spring contacts the side wall of the air intake baffle, and the other force-bearing end of the torsion spring is connected to the outer peripheral surface of the inner ring of the nozzle in the air intake guide channel.

[0009] Preferably, a first groove is provided on each of the opposite surfaces in the middle of the two leading edge plates, the end of the rotating shaft is fixedly connected to the groove wall of the first groove corresponding to the leading edge plate, a second groove is provided on the outer peripheral surface of the inner ring of the nozzle between the two first grooves, and a connecting hole is provided on the second groove, wherein the force-bearing end of the torsion spring is connected to the connecting hole.

[0010] Preferably, the length of the second groove is 2 mm greater than the length of the air intake baffle, and the width of the second groove is 2 mm greater than the width of the air intake baffle.

[0011] Preferably, a plurality of through grooves are provided on the outer ring of the nozzle, and each through groove corresponds one-to-one to the second groove on the inner ring of the nozzle.

[0012] Preferably, there is an interference fit of 0.1 mm between the nozzle inner ring and the nozzle outer ring.

[0013] Preferably, both the nozzle inner ring and the nozzle outer ring are provided with pin holes for connecting the nozzle inner ring and the nozzle outer ring, and the pin holes are provided in the leading edge region of the nozzle inner ring.

[0014] Preferably, the centerline direction of the air intake guide channel is parallel to the incoming flow direction.

[0015] A pre-swirl air supply system comprises the device for adaptively adjusting the air intake flow of the pre-swirl air supply system according to the present invention.

[0016] The beneficial effects of the present invention are: 1. The present invention autonomously controls the corresponding intake baffle to rotate around the rotating shaft according to the intake pressure of the engine under different working conditions and the preload force provided by the torsion spring of the intake baffle, so as to adjust the total intake area of ​​the leaf hole type pre-swirl nozzle, thereby autonomously adjusting the air intake volume of the pre-swirl air supply system and improving the engine operation efficiency.

[0017] 2. The traditional method of actively controlling the amount of bleed air mainly controls the size of the flow area through the final valve of the upstream compressor, which has the problem of long adjustment time. Compared with the prior art, the present invention adjusts the size of the total intake area of ​​the leaf hole type pre-swirl nozzle in real time according to the change of intake pressure under different engine working conditions, thereby realizing real-time adjustment of the amount of bleed air in the pre-swirl air supply system under different engine working conditions, significantly improving the response speed and adjustment efficiency of the system.

[0018] 3. The present invention designs an air intake guide assembly in front of the existing blade hole type pre-swirl nozzle, and sets an air intake baffle in the air intake guide assembly to control the total area of ​​the pre-swirl nozzle. This design does not change the shape and position of the pressure surface and suction surface of the blade hole type pre-swirl nozzle, so it has almost no adverse effect on the acceleration and flow performance of the pre-swirl nozzle, and maintains the efficient air entrainment capability of the pre-swirl nozzle.

[0019] The pre-swirl nozzle device of the present invention, which is used for the self-regulating function of the pre-swirl air supply system, is simple and convenient to process and install. The nozzle leading edge extension section and the leaf hole nozzle and its nozzle inner ring are processed as a whole, a pit is processed on the nozzle leading edge extension section to install the air intake baffle, and a blind hole is processed on the nozzle inner ring to install long screws to fix the torsion spring and the air intake baffle. Finally, the outer ring of the nozzle is processed, and the pit is also processed on the outer ring of the nozzle to install the air intake baffle. The pit of the inner ring of the nozzle corresponds to the pit of the outer ring of the nozzle one by one. During assembly, the torsion spring and the air intake baffle are first fixed in the pit by long screws, and then the outer ring of the nozzle is nested on the inner ring of the nozzle, and the inner and outer rings of the nozzle are fastened and connected by pins. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a partial structure enlarged diagram of a device for adaptively adjusting the intake air flow rate of a pre-swirl air supply system of the present invention; Figure 2 A schematic diagram of the structure of an air intake baffle, a torsion spring and a rotating shaft in an embodiment of the present invention; Figure 3 This is the assembly drawing of the nozzle inner ring and the nozzle outer ring; Figure 4 It is a schematic diagram of the structure of the inner ring of the nozzle; Figure 5 It is a schematic diagram of the structure of the nozzle outer ring; Figure 6 It is a schematic diagram of the through groove on the outer ring of the nozzle; Figure 7 A schematic diagram of an air intake guide channel of an air intake guide assembly.

[0022] In the figure: 1. leading edge plate; 2. air intake baffle; 3. torsion spring; 4. air intake guide channel; 5. second groove; 6. pin hole; 7. leaf hole type pre-swirl nozzle; 8. rotating shaft; 9. through groove. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] An embodiment of a device for adaptively adjusting the intake air flow rate of a pre-swirl air supply system of the present invention is as follows: Figure 1 As shown, it includes: an air intake baffle 2 and six air intake guide components, such as Figure 4 As shown, six air intake guide assemblies are arranged on the inner ring of the nozzle at equal intervals, and each air intake guide assembly is connected to the leading edge of the blade of a leaf hole type pre-swirl nozzle 7, an air intake guide channel 4 is formed in the air intake guide assembly, and the air intake guide channel 4 is connected to the nozzle flow channel of the corresponding leaf hole type pre-swirl nozzle 7; an air intake baffle 2 is rotatably arranged in the air intake guide channel 4 of each air intake guide assembly through a rotating shaft 8, and a torsion spring 3 for providing a pre-tightening force for the air intake baffle 2 is arranged on the rotating shaft 8. In the pre-tightening state, the air intake baffle 2 is perpendicular to the surface of the inner ring of the nozzle, and the air intake baffle 2 is driven to rotate by the differential pressure of the intake pressure under different cruising conditions and the pre-tightening force of the torsion spring 3, so as to adjust the air intake area entering the leaf hole type pre-swirl nozzle 7.

[0025] It should be noted that the flow channels of the vane hole type pre-swirl nozzle 7 of the present embodiment are thick solid domains, which are suitable for extending the leading edge of the pre-swirl nozzle. The vane hole type pre-swirl nozzle 7 adopts the vane hole type pre-swirl nozzle structure in the existing patent with application number CN20150472608.9. Then, an intake baffle 2 is arranged on the basis of the vane hole type pre-swirl nozzle 7. Because the high-temperature turbine blades require more cooling air under the high cruise condition of the engine, the pressure difference before and after the vane hole type pre-swirl nozzle 7 increases at this time. The present invention can autonomously adjust the rotation angle of the intake baffle 2 according to the change of the pressure difference before and after the nozzle, thereby increasing the intake area of ​​the pre-swirl nozzle and preventing the insufficient supply of cooling air required by the turbine blades, thereby improving the safety and reliability of the engine.

[0026] Specifically, the air intake guide assembly includes: two leading edge plates 1, the leading edge plates 1 are arranged on the outer peripheral surface of the inner ring of the nozzle, the ends of the leading edge plates 1 are connected to the leading edges of the blades of the leaf hole type pre-swirl nozzle 7 of the inner ring of the nozzle, and an air intake guide channel 4 is formed between the two leading edge plates 1.

[0027] Specifically, two connecting ears are provided on the end face of the air intake baffle 2, the rotating shaft 8 is passed through the two connecting ears, the torsion spring 3 is sleeved on the rotating shaft 8 between the two connecting ears, and one force-bearing end of the torsion spring 3 contacts the side wall of the air intake baffle 2, and the other force-bearing end of the torsion spring 3 is connected to the outer peripheral surface of the inner ring of the nozzle in the air intake guide channel 4.

[0028] Specifically, a first groove is opened on each of the opposite surfaces in the middle of the two leading edge plates 1, the end of the rotating shaft 8 is fixedly connected to the groove wall of the first groove corresponding to the leading edge plate 1, and a second groove 5 is opened on the outer peripheral surface of the inner ring of the nozzle between the two first grooves, and a connecting hole is opened on the second groove 5, wherein the force-bearing end of the torsion spring 3 is connected to the connecting hole.

[0029] As shown in the figure, in order to ensure that the air intake baffle 2 can rotate freely and flexibly under the pressure difference between the intake air flow and the torsion spring 3, the length of the second groove 5 in this embodiment is 2 mm larger than the length of the air intake baffle 2, and the width of the second groove 5 is 2 mm larger than the width of the air intake baffle 2.

[0030] like Figure 5 and 6 As shown, a plurality of through grooves 9 are provided on the nozzle outer ring, and each through groove 9 corresponds one-to-one to the second groove 5 on the nozzle inner ring, wherein the through grooves 9 are used to avoid affecting the rotation of the intake baffle 2 when the intake baffle 2 rotates.

[0031] Specifically, the channel shape of the air intake guide channel 4 is determined by the shape of the air intake baffle 2, and can be rectangular or trapezoidal, which will not be described in detail in this embodiment.

[0032] like Figure 3 As shown, there is an interference fit of 1 mm between the nozzle inner ring and the nozzle outer ring, and both the nozzle inner ring and the nozzle outer ring are provided with a pin hole 6 for connecting the nozzle inner ring and the nozzle outer ring, and the pin hole is provided in the front edge area of ​​the nozzle inner ring, and the pin hole of the nozzle inner ring and the nozzle outer ring is connected by a pin. Figure 4 and Figure 5 As shown, in this embodiment, the nozzle inner ring and the nozzle outer ring are processed separately, and a plurality of leaf hole type pre-swirl nozzles 7 are evenly distributed on the outer peripheral surface of the nozzle inner ring, and the leaf height of the leaf hole type pre-swirl nozzle 7 is equal to the radial height of the leading edge plate 1. In addition, a plurality of pin holes are evenly distributed on the nozzle inner ring and the nozzle outer ring. In order to avoid a significant impact on the flow of airflow, the pin holes are placed on the nozzle inner ring on the leading edge side of the leaf hole type pre-swirl nozzle 7. During assembly, first install the torsion spring 3 and the air intake baffle 2, and fix the air intake baffle 2 in the first groove 5 of the nozzle inner ring with the rotating shaft 8, and then connect the nozzle inner ring and the nozzle outer ring to ensure an interference fit of 0.1 mm in diameter between the nozzle inner ring and the nozzle outer ring, and assemble by heating the outer ring.

[0033] A pre-swirl air supply system comprises the device for adaptively adjusting the air intake flow of the pre-swirl air supply system according to the present invention.

[0034] How it works like Figures 1 to 3As shown, when the engine is in high cruise condition, the intake pressure generated by the higher flow rate and pressure of the incoming flow is greater than the preload force of the torsion spring 3 of the intake baffle 2. At this time, the intake baffle 2 is driven to rotate around the rotating shaft 8 under the pressure difference between the intake pressure and the preload force, until the intake baffle 2 gradually rotates around the rotating shaft 8 autonomously until it is close to the second groove 5. At this time, the intake area of ​​the leaf hole type pre-swirl nozzle 7 is increased, the intake baffle 2 is in full open mode, and the air intake amount of the pre-swirl air supply system is also increased accordingly, thereby meeting the demand of the high-temperature turbine blades for cooling air, that is, all the airflow in this flow path in the high cruise condition enters the pre-swirl air supply system; when the engine is in low cruise condition, the rotation speed of the engine rotor components is low, and the amount of cooling air required by the turbine blades is also low. At this time, the pressure difference before and after the leaf hole type pre-swirl nozzle 7 is reduced, acting on the intake baffle. 2 is less than the preload force of the torsion spring 3 of the intake baffle 2. At this time, the intake baffle 2 is automatically rotated back to its original position under the pressure difference between the preload force of the torsion spring 3 and the intake pressure. At this time, the intake baffle 2 is in full-close mode, the intake area of ​​the leaf hole pre-swirl nozzle 7 is reduced, and the air intake of the pre-swirl air supply system is reduced to a suitable range, which not only ensures sufficient cooling air for the turbine blades, but also improves the thrust-to-weight ratio and operating efficiency of the engine, and reduces the fuel consumption rate, that is, in low cruise conditions, no airflow enters the pre-swirl air supply system in this flow path; and in other cruise conditions, the intake baffle 2 drives the intake baffle 2 to rotate around the rotating shaft 8 according to the pressure difference between the intake pressure and the preload force to achieve the corresponding opening adjustment, that is, the partial opening mode, which is manifested as part of the airflow in this flow path entering the pre-swirl air supply system. Therefore, the present invention can autonomously adjust the intake area of ​​the leaf hole pre-swirl nozzle 7 through the intake baffle 2 according to different engine working conditions to meet the demand of the pre-swirl air supply system for the air intake.

[0035] Secondly, during assembly, the torsion spring 3 and the air intake baffle 2 are first fixed in the second groove by the rotating shaft 8, and then the nozzle outer ring is nested in the nozzle inner ring, and the nozzle inner ring and the nozzle outer ring are fastened with pins.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for adaptively adjusting the intake air flow of a pre-swirl air supply system, characterized in that: include: A plurality of air intake guide assemblies are evenly distributed on the inner ring of the nozzle, and each air intake guide assembly is connected to the leading edge of a blade of a leaf hole type pre-swirl nozzle (7), an air intake guide channel (4) is formed in the air intake guide assembly, and the air intake guide channel (4) is connected to the nozzle flow channel of the corresponding leaf hole type pre-swirl nozzle (7); An air intake baffle (2) is rotatably arranged in the air intake guide channel (4) via a rotating shaft (8), and a torsion spring (3) is arranged on the rotating shaft (8) for providing a preload force for the air intake baffle (2). In the preload force state, the air intake baffle (2) is perpendicular to the surface of the inner ring of the nozzle, and the air intake baffle (2) is driven to rotate by the differential pressure between the air intake pressure under different cruising conditions and the preload force of the torsion spring (3), so as to adjust the air intake area entering the leaf hole type pre-swirl nozzle (7).

2. A device for adaptively adjusting the intake air flow of a pre-swirl air supply system according to claim 1, characterized in that: The air intake guide assembly comprises: two leading edge plates (1), the leading edge plates (1) being arranged on the outer peripheral surface of the nozzle inner ring, the ends of the leading edge plates (1) being connected to the leading edges of blades of a leaf hole type pre-swirl nozzle (7) of the nozzle inner ring, and an air intake guide channel (4) being formed between the two leading edge plates (1).

3. A device for adaptively adjusting the intake air flow of a pre-swirl air supply system according to claim 2, characterized in that: The end surface of the air intake baffle (2) is provided with two connecting ears, the rotating shaft (8) is inserted through the two connecting ears, the torsion spring (3) is sleeved on the rotating shaft (8) between the two connecting ears, and one force-bearing end of the torsion spring (3) contacts the side wall of the air intake baffle (2), and the other force-bearing end of the torsion spring (3) is connected to the outer peripheral surface of the inner ring of the nozzle in the air intake guide channel (4).

4. A device for adaptively adjusting the intake air flow of a pre-swirl air supply system according to claim 3, characterized in that: A first groove is respectively formed on the opposite surfaces in the middle of the two leading edge plates (1); the end of the rotating shaft (8) is fixedly connected to the groove wall of the first groove corresponding to the leading edge plate (1); a second groove (5) is formed on the outer peripheral surface of the nozzle inner ring between the two first grooves; a connecting hole is formed on the second groove (5), wherein the force-bearing end of the torsion spring (3) is connected to the connecting hole.

5. The device for adaptively adjusting the intake air flow of a pre-swirl air supply system according to claim 4, characterized in that: The length of the second groove (5) is greater than the length of the air intake baffle (2), and the width of the second groove (5) is greater than the width of the air intake baffle (2) by 1 mm to 3 mm.

6. The device for adaptively adjusting the intake air flow of a pre-swirl air supply system according to claim 4, characterized in that: A plurality of through grooves (9) are provided on the nozzle outer ring, and each through groove (9) corresponds one-to-one to a second groove (5) on the nozzle inner ring.

7. The device for adaptively adjusting the intake air flow of a pre-swirl air supply system according to claim 1, characterized in that: There is interference fit between the nozzle inner ring and the nozzle outer ring.

8. The device for adaptively adjusting the intake air flow of a pre-swirl air supply system according to claim 1, characterized in that: The nozzle inner ring and the nozzle outer ring are both provided with pin holes (6) for connecting the nozzle inner ring and the nozzle outer ring, and the pin holes (6) are arranged in the front edge area of ​​the nozzle inner ring.

9. The device for adaptively adjusting the intake air flow of a pre-swirl air supply system according to claim 1, characterized in that: The centerline direction of the air intake guide channel (4) is parallel to the incoming flow direction.

10. A pre-swirl air supply system, characterized in that: The invention comprises a device for adaptively adjusting the air intake flow rate of a pre-swirl air supply system as described in any one of claims 1 to 9.

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