Nozzle area adjustable device for prewhirl air supply system

Abstract

The invention relates to the technical field of aero-engine prewhirl air supply systems, in particular to a nozzle area adjustable device for a prewhirl air supply system, which comprises a plurality of air inlet guide components, a plurality of air inlet baffles and a driving component, 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 baffles are arranged on the nozzle outer ring in a penetrating mode in the radial direction, and the air inlet baffles correspond to the air inlet guide assemblies in a one-to-one mode. The driving assembly is used for driving the multiple synchronous air inlet baffles to enter the air inlet flow guide channel so as to adjust the air inlet area of the air inlet flow guide channel. The total air inlet area of the nozzle flow channel can be effectively controlled, so that the air entraining amount of the pre-whirl air supply system is actively controlled, and the operation efficiency of an engine is improved.

Description

Technical Field

[0001] The invention relates to the technical field of a pre-swirl air supply system for an aero-engine, and in particular to a nozzle area adjustable device for a pre-swirl air supply system. Background Art

[0002] Aircraft engines are constantly developing towards the goal of high thrust-to-weight ratio and high efficiency. One of the main ways to achieve this is to increase the turbine inlet temperature and the compression ratio. The increase in the temperature before the turbine seriously deteriorates the working environment of the high-temperature components in the engine, resulting in poor engine reliability and shortened life. Turbine blades are effectively cooled by cooling air through rib flow cooling, impingement cooling and film cooling. In addition, engine designers have also proposed a pre-swirl air supply system, the function of which is to provide high-quality cooling air that meets the flow and pressure conditions for the turbine rotor blades, thereby reducing the amount of cold air used and ensuring the reliable operation of high-temperature components.

[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 speed 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 cooling effect alone, the more cooling air is used, the better the effect. However, the cooling air drawn from the compressor will not do work in the turbine, which will reduce the thrust generated by the engine. Therefore, the size of the bleed air volume of the pre-swirl air supply system will directly affect the performance of the whole machine. The design value of the bleed air volume of the pre-swirl air supply system is generally taken as the value when the amount of cooling air required by the turbine blades is the largest, which means that the engine has excessive cooling air under other working conditions, and excessive cooling air bleed air will affect the operating efficiency of the engine. Reducing the bleed air volume at non-design points can reduce fuel consumption and increase thrust-to-weight ratio. Therefore, actively controlling the bleed air flow of the pre-swirl air supply system under different flight conditions of the aircraft engine is of great significance to increasing the operating efficiency of the engine.

[0004] In the prior art, the method of actively controlling the bleed air flow of the pre-swirl air supply system is to divide the nozzle flow path into a normally open flow path and an adjustable flow path through a partition. This method can open the adjustable flow path at the engine design point by controlling the valve at the compressor outlet to ensure the cooling air volume of the turbine blades, and close the adjustable flow path at the non-design point to reduce the cooling air volume. Therefore, the traditional method only has two states of the switch adjustable flow path, which are respectively applicable to the two working conditions of the engine design point and the non-design point. However, when the aircraft engine has multiple non-design point working conditions that require active control of the bleed air volume of the pre-swirl air supply system, this method cannot meet the cooling air volume requirements of the turbine blades under each working condition.

[0005] Therefore, it is necessary to provide a nozzle area adjustable device for a pre-swirl air supply system to solve the above problems. Summary of the invention

[0006] The present invention provides a device for adjusting the nozzle area of ​​a pre-swirl air supply system, so as to solve the problem that the existing method has only two states of an on-off adjustable flow path, which are respectively applicable to two working conditions of an engine design point and a non-design point. However, when an aircraft engine has multiple non-design point working conditions that require active control of the bleed air volume of the pre-swirl air supply system, this method cannot meet the demand for cooling air volume of turbine blades under each working condition.

[0007] The nozzle area adjustable device for a pre-swirl air supply system of the present invention adopts the following technical solution, 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; An air intake baffle is radially arranged on the outer ring of the nozzle, and the air intake baffle corresponds to the air intake guide assembly one by one; And a driving component is used to drive multiple air intake baffles to synchronously enter the corresponding air intake guide channels to adjust the air intake area of ​​the air intake guide channels.

[0008] 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.

[0009] Preferably, a through slot for passing an air intake baffle is provided on the outer ring of the nozzle, and guide slots corresponding to the through slot are provided on the two leading edge plates, wherein the driving assembly is used to drive the air intake baffle to pass through the through slot and enter the guide slot.

[0010] Preferably, the radial height of the leading edge plate is the same as the blade height of the hole-type pre-swirl nozzle.

[0011] Preferably, the driving assembly comprises a plurality of linear motors, the plurality of linear motors are controlled and driven synchronously, and the output end of each linear motor is connected to the corresponding air intake baffle.

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

[0013] Preferably, the nozzle inner ring and the nozzle outer ring are connected by pins, and the pins are arranged in the leading edge area of ​​the nozzle inner ring.

[0014] A pre-swirl air supply system comprises a nozzle area adjustable device for the pre-swirl air supply system according to the present invention.

[0015] An aircraft engine comprises the pre-swirl air supply system of the present invention.

[0016] The beneficial effects of the present invention are: 1. The intake baffle is driven by the driving assembly to move radially along the outer ring of the nozzle, so that the intake baffle enters the intake guide channel of the intake guide assembly. Since the intake guide channel is connected to the nozzle flow channel of the nozzle, the area of ​​the intake nozzle flow channel is changed. The total intake area of ​​the nozzle flow channel can be effectively controlled by multiple intake baffles, thereby actively controlling the amount of air intake of the pre-swirl air supply system and improving the engine operation efficiency.

[0017] 2. The present invention controls the total area of ​​the pre-swirl nozzle by controlling the area of ​​the air intake guide channel in front of the leaf hole pre-swirl nozzle, without changing the shape and position of the pressure surface and suction surface of the leaf hole pre-swirl nozzle, so it will hardly have an adverse effect on the acceleration and flow performance of the pre-swirl nozzle. In other words, in the process of regulating the air intake area of ​​the pre-swirl nozzle by using the present invention, the pre-swirl nozzle still maintains a high acceleration and flow performance. In the range of the nozzle pressure ratio of 1.445 to 1.506, when the air intake area of ​​the pre-swirl nozzle is controlled by the present invention to be between 75% and 100%, the flow coefficient of the pre-swirl nozzle varies in the range of 0.927 to 0.933, and the nozzle performance fluctuation range is less than 0.7%. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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.

[0019] Figure 1 It is a partial schematic diagram of a nozzle area adjustable device for a pre-swirl air supply system of the present invention; Figure 2 It is a structural schematic diagram of a driving assembly and an air intake baffle for a nozzle area adjustable device for a pre-swirl air supply system of the present invention; Figure 3 It is a schematic diagram of the overall structure of a nozzle area adjustable device for a pre-swirl air supply system of the present invention; Figure 4 Schematic diagram of the structure of the inner ring of the nozzle in an embodiment of the present invention; Figure 5 is a schematic structural diagram of a nozzle outer ring in an embodiment of the present invention; Figure 6 Schematic diagram of the through groove on the outer ring of the nozzle in an embodiment of the present invention; Figure 7 It is a schematic structural diagram of the air intake guide assembly on the inner ring of the nozzle in an embodiment of the present invention.

[0020] In the figure: 1. leading edge plate; 2. air intake baffle; 3. linear motor; 4. air intake guide channel; 5. through groove; 6. leaf hole type pre-swirl nozzle; 7. guide groove. DETAILED DESCRIPTION

[0021] 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.

[0022] An embodiment of the nozzle area adjustable device for a pre-swirl air supply system of the present invention is as follows: Figure 1 As shown, it includes: a plurality of air intake guide components, a plurality of air intake baffles 2 and a plurality of driving components, the plurality of air intake guide components are evenly arranged on the inner ring of the nozzle, and each air intake guide component is connected to the leading edge of a blade of a leaf hole type pre-swirl nozzle 6, an air intake guide channel 4 is formed in the air intake guide component, and the air intake guide channel 4 is connected to the nozzle flow channel of the corresponding leaf hole type pre-swirl nozzle 6; Figure 3 , Figure 4 and 5 As shown, a plurality of air intake baffles 2 are evenly distributed on the circumference of the nozzle outer ring, and the air intake baffles 2 are radially penetrated on the nozzle outer ring, and each air intake baffle 2 corresponds to an air intake guide assembly; a plurality of driving assemblies are used to synchronously drive the corresponding air intake baffles 2 into the air intake guide channel 4 to adjust the air intake area of ​​the air intake guide channel 4; the blade hole type pre-swirl nozzle of this embodiment adopts the blade hole type pre-swirl nozzle in patent number CN20150472608.9.

[0023] like Figure 7 As shown, 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 6, and an air intake guide channel 4 is formed between the two leading edge plates 1; the radial height of the leading edge plate 1 is the same as the blade height of the leaf hole type pre-swirl nozzle 6. It should be noted that the air intake guide channel 4 is directly connected to the nozzle flow channel opening formed by the blades of the leaf hole type pre-swirl nozzle.

[0024] like Figure 6As shown, a through slot 5 for penetrating the air intake baffle 2 is provided on the outer ring of the nozzle. The shape and size of the through slot 5 are consistent with the air intake baffle 2, ensuring that the air intake baffle 2 can be inserted from the through slot 5. The through slots 5 are evenly distributed in the circumferential direction of the outer ring of the nozzle, and correspond one-to-one with the guide channels 4 of the air intake guide assembly. The two leading edge plates 1 are provided with guide slots 7 corresponding to the through slots 5, wherein the driving assembly is used to drive the air intake baffle 2 to pass through the through slots 5 and enter the guide slots 7. The length and width of the guide slots 7 are consistent with the length and width of the air intake baffle 2. Several air intake guide channels 4 are evenly distributed on the outer circumferential surface of the inner ring of the nozzle, and correspond one-to-one with the air intake baffle 2.

[0025] like Figure 2 As shown, the driving assembly includes a plurality of linear motors 3 , and the plurality of linear motors 3 are synchronously controlled and driven, and the output end of each linear motor 3 is connected to the corresponding air intake baffle 2 .

[0026] like Figure 4 and Figure 5 As shown in the figure, when processing the pre-swirl nozzle, the inner ring and the outer ring of the nozzle are processed separately. Several leaf hole type pre-swirl nozzle blades are evenly distributed on the inner ring of the nozzle in the circumferential direction. The leaf height of the leaf hole type pre-swirl nozzle blade is equal to the radial height of the leading edge plate 1. In addition, several pin holes are evenly distributed on the inner ring and the outer ring of the nozzle. The inner ring and the outer ring of the nozzle are connected by pins. In order to avoid a significant impact on the flow of airflow, the pin holes are placed in the leading edge area of ​​the leaf hole type pre-swirl nozzle blade. During assembly, ensure an interference fit of 0.1mm in diameter between the inner ring and the outer ring of the nozzle, and use the outer ring heating method for assembly.

[0027] A pre-swirl air supply system comprises a nozzle area adjustable device for the pre-swirl air supply system according to the present invention.

[0028] An engine comprises the pre-swirl air supply system of the present invention.

[0029] The present invention is described below in conjunction with specific embodiments: In this embodiment, for four operating points (operating point 1, operating point 2, operating point 3, and operating point 4) of a certain aircraft engine, the pre-swirl nozzle inlet area is controlled to meet the demand of turbine blades for the air intake of the pre-swirl air supply system at operating points 1 to 4: The pre-swirl nozzle inlet area, number of nozzles, nozzle radius position, and number of adjustable devices at operating points 1 to 4 are determined by the boundary conditions of the pre-swirl air supply system and the overall design of the pre-swirl. The specific system structure is: the number of nozzle rings is 24, the nozzle, receiving hole and air supply hole are located at the same radius, the nozzle pre-swirl angle is 15°, the pre-swirl air supply system adopts a leaf hole pre-swirl nozzle, a leaf type receiving hole structure, and the cover plate cavity structure is removed. Table 1 is the boundary conditions of the pre-swirl air supply system operating points 1 to 4. It can be seen that due to the large differences in the system pressure ratio and inlet total temperature of the pre-swirl air supply system at operating points 1 to 4, the turbine blades have different requirements for the cooling air volume of the pre-swirl air supply system under different operating conditions, and the demand range is between 0.242kg / s and 0.655kg / s.

[0030] Table 1

[0031] In order to actively control the bleed air volume of the pre-swirl air supply system under different working conditions and improve the operating efficiency of the aircraft engine, six nozzle area adjustable devices for the pre-swirl air supply system of the present invention are evenly installed circumferentially on the nozzle ring. Table 2 shows the nozzle air intake area, the bleed air volume of the pre-swirl air supply system, the nozzle flow coefficient and the temperature drop efficiency of the pre-swirl air supply system at working points 1 to 4 obtained by CFD numerical simulation. It can be seen from mark 2 that the nozzle area adjustable device for the pre-swirl air supply system of this embodiment can flexibly adjust the nozzle air intake area according to different working conditions of the pre-swirl air supply system, so that the bleed air volume just meets the cooling air volume demand of the turbine blades for the pre-swirl air supply system under different working conditions, thereby realizing that the pre-swirl air supply system can actively control the size of the bleed air volume under different working conditions and improve the operating efficiency of the engine. In addition, the present invention hardly affects the temperature drop performance and flow performance of the pre-swirling air supply system when it is working. When the pre-swirling air supply system is at operating points 1 to 4 (the system pressure ratio range is 1.44 to 1.52), the nozzle flow coefficient maintains a relatively high level of 0.927 to 0.933, and the system temperature drop is between 40.44K and 63.01K, which is higher than the overall temperature drop level of the current pre-swirling air supply system.

[0032] Table 2

[0033] How it works When in use, according to the air intake demand, multiple linear motors 3 are synchronously controlled to work, and the linear motors 3 drive the air intake baffle 2 to block the air intake guide channel 4, so as to adjust the area of ​​the nozzle flow channel.

[0034] 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 nozzle area adjustable device for 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 (6), 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 (6); An air intake baffle (2) is radially penetrated on the outer ring of the nozzle, and the air intake baffle (2) corresponds to the air intake guide assembly one by one; And a driving component, used for driving the plurality of air intake baffles (2) to synchronously enter the corresponding air intake guide channels (4) to adjust the air intake area of ​​the air intake guide channels (4).

2. The nozzle area adjustable device for 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 (6) of the nozzle inner ring, and an air intake guide channel (4) being formed between the two leading edge plates (1).

3. The nozzle area adjustable device for a pre-swirl air supply system according to claim 2, characterized in that: A through slot (5) for passing the air intake baffle (2) is provided on the outer ring of the nozzle, and guide slots (7) corresponding to the through slot (5) are provided on the two leading edge plates (1), wherein the drive assembly is used to drive the air intake baffle (2) to pass through the through slot (5) and enter the guide slot (7).

4. The nozzle area adjustable device for a pre-swirl air supply system according to claim 2, characterized in that: The radial height of the leading edge plate (1) is the same as the blade height of the leaf hole type pre-swirl nozzle (6).

5. The nozzle area adjustable device for a pre-swirl air supply system according to claim 1, characterized in that: The drive assembly comprises a plurality of linear motors (3), the plurality of linear motors (3) are synchronously controlled and driven, and the output end of each linear motor (3) is connected to a corresponding air intake baffle (2).

6. The nozzle area adjustable device for 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.

7. The device for adjusting the nozzle area of ​​a pre-swirl air supply system according to claim 1, characterized in that: The nozzle inner ring and the nozzle outer ring are connected by pins, and the pins are arranged in the front edge area of ​​the nozzle inner ring.

8. A pre-swirl air supply system, characterized in that: The invention comprises a nozzle area adjustable device for a pre-swirl air supply system as described in any one of claims 1 to 7.

9. An aircraft engine, characterized in that: It includes the pre-swirl air supply system as described in claim 8.

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