Compressor end wall leakage flow control device and method based on rotating wall surface control

Abstract

The invention relates to a compressor end wall leakage flow control device and method based on rotating wall surface control. The plurality of rotor assemblies are arranged on the central shaft in series at intervals; the rotor assembly comprises a forward rotation rotor and a reverse rotation rotor, the forward rotation rotor is arranged on the center shaft in a sleeving mode, the reverse rotation rotor is arranged outside the forward rotation rotor in a sleeving mode, and a blade rotation space is reserved between the forward rotation rotor and the reverse rotation rotor; the forward rotation rotor and the reverse rotation rotor are driven by a driving mechanism to rotate, and the rotation directions are opposite. By controlling the gap between the blade tip and the rotary casing and the gap between the blade root and the hub, the pressure ratio, the efficiency and the working stability of the compressor are further improved while the development of end wall leakage flow is controlled.

Description

Technical Field

[0001] The invention relates to a compressor end wall leakage flow control device and method based on rotating wall surface control, belonging to the technical field of compressors of aircraft engines and gas turbines. Background Art

[0002] End wall leakage flow refers to the phenomenon that in the compressor, there is a certain gap between the blade tip or blade root and the end wall or hub, and the airflow leaks through this gap. In the existing counter-rotating compressors, the blades are usually connected to the hub through tongue and groove, and the tip gap only exists between the blade tip and the casing, so there will be a tip leakage flow problem. As the speed of the compressor increases, the leakage flow continues to develop at the blade tip position, which will lead to a decrease in the single-stage efficiency of the compressor, causing overall instability of the machine, and even airflow reversal, reducing the overall performance of the compressor.

[0003] Patents for controlling leakage flow have been disclosed. For example, patent CN107061363A suppresses tip leakage flow by changing the blade top design, and patent CN118188048A controls tip leakage flow by changing the grate seal structure on the casing. Summary of the invention

[0004] In response to the above technical problems, the present invention provides a compressor end wall leakage flow control device and method based on rotating wall control. The device controls the gap between the blade tip and the rotating casing and the gap between the blade root and the hub, thereby controlling the development of the end wall leakage flow and further improving the pressure ratio, efficiency and operating stability of the impeller.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A compressor end wall leakage flow control device based on rotating wall surface control, comprising:

[0007] Central axis;

[0008] A plurality of rotor assemblies, wherein the plurality of rotor assemblies are arranged in series on the central shaft at intervals; the rotor assembly comprises a forward rotor and a reverse rotor, wherein the forward rotor is sleeved on the central shaft, and the reverse rotor is sleeved on the outside of the forward rotor, and a blade rotation space is left between the two;

[0009] The forward rotor and the reverse rotor rotate in opposite directions under the driving of the driving mechanism.

[0010] In the compressor end wall leakage flow control device based on rotating wall surface control, preferably, the reversing rotor includes a rotating casing, the rotating casing is an annular structure, and a plurality of reversing rotor blades are evenly spaced along the circumferential inner wall surface of the rotating casing.

[0011] In the compressor end wall leakage flow control device based on rotating wall surface control, preferably, the forward-rotating rotor comprises a forward-rotating rotor hub, and a plurality of forward-rotating rotor blades are evenly spaced on the circumferential outer wall surface of the forward-rotating rotor hub.

[0012] In the compressor end wall leakage flow control device based on rotating wall surface control, preferably, a gap is left between a plurality of the forward-rotating rotor blades and the circumferential inner wall surface of the rotating casing.

[0013] The compressor end wall leakage flow control device based on rotating wall surface control is preferably configured such that a gap is left between a plurality of the counter-rotating rotor blades and the circumferential outer wall surface of the forward-rotating rotor hub.

[0014] In the compressor end wall leakage flow control device based on rotating wall surface control, preferably, the number of the plurality of reverse rotating rotor blades is the same as the number of the plurality of forward rotating rotor blades, and they are arranged in a one-to-one correspondence.

[0015] In the compressor end wall leakage flow control device based on rotating wall surface control, preferably, some of the counter-rotating rotor blades and some of the forward-rotating rotor blades are arc-shaped blades.

[0016] In the compressor end wall leakage flow control device based on rotating wall surface control, preferably, the number of the rotor assemblies is ten.

[0017] A second aspect of the present invention provides a working method of a compressor end wall leakage flow control device based on rotating wall surface control, comprising the following steps:

[0018] The driving mechanism is started, and the rotor assembly rotates under the driving of the driving mechanism, and the forward rotor and the reverse rotor rotate in opposite directions;

[0019] The medium to be compressed enters the leakage flow control device of the compressor end wall, and the medium rotates under the drive of the forward-rotating rotor blades in the first rotor assembly. A part of the medium in the gap between the forward-rotating rotor and the rotating casing flows downstream to the reverse-rotating rotor blades, and the kinetic energy is replenished by the blades doing work, and the medium rotates. A part of the medium that is not driven enters the next rotor assembly through the gap between the reverse rotor and the hub, and the rotation action of the first rotor assembly is repeated again.

[0020] After the compressed medium flows through several rotor assemblies, most of the medium rotates, thereby reducing flow losses and blockages caused by leakage flow.

[0021] The present invention adopts the above technical solution, which has the following advantages:

[0022] 1. Each group of rotors in the device of the present invention is divided into a forward rotor and a reverse rotor. The forward rotor controls the leakage flow by controlling the gap between the blade tip and the rotating casing, and the reverse rotor controls the leakage flow by controlling the gap between the blade root and the hub, thereby suppressing the leakage flow from aggravating the leakage vortex, further weakening the mixing of the secondary flow and the mainstream, and reducing the flow loss and blockage caused by the leakage flow.

[0023] 2. The device of the present invention has a total of ten groups of rotors and twenty rows of rotors distributed axially. The gap position between each row of blades and the rotating wall is alternately located at the blade root and the blade tip. This can inhibit the leakage flow from further expanding and developing along the axial position, affecting the compression ratio, efficiency and working margin of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A three-dimensional diagram of a compressor end wall leakage flow control device provided by one embodiment of the present invention;

[0025] Figure 2 A schematic diagram of a group of rotors in the compressor end wall leakage flow control device provided by the embodiment of the present invention, wherein FIG a is a stereoscopic diagram viewed from the direction of the forward rotating rotor, and FIG b is a stereoscopic diagram viewed from the direction of the reverse rotating rotor;

[0026] Figure 3 A front view of a group of rotors in the compressor end wall leakage flow control device provided by this embodiment of the present invention, wherein Figure a is a front view from the direction of the forward rotating rotor, and Figure b is a front view from the direction of the reverse rotating rotor;

[0027] Figure 4 A schematic diagram of a set of rotors provided in this embodiment of the present invention, wherein Figure a is a front view of a forward-rotating rotor, and Figure b is a front view of a reverse-rotating rotor;

[0028] Figure 5 A two-dimensional schematic diagram of a set of rotors provided for this embodiment of the present invention;

[0029] Figure 6 A two-dimensional schematic diagram of a forward-rotating rotor provided in this embodiment of the present invention;

[0030] Figure 7 A two-dimensional schematic diagram of a counter-rotating rotor provided for this embodiment of the present invention;

[0031] Figure 8 A schematic diagram of the gap between the forward-rotating rotor and the rotating casing and the gap between the reverse-rotating rotor and the wheel hub provided in this embodiment of the present invention;

[0032] The reference numerals in the figures are as follows:

[0033] 1-forward-rotating rotor, 11-central axis, 12-forward-rotating rotor hub, 13-forward-rotating rotor blades;

[0034] 2-reverse rotor; 21-rotating casing, 22-reverse rotor blades;

[0035] 3- The gap between the forward-rotating rotor and the rotating casing; 4- The gap between the reverse-rotating rotor and the wheel hub. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are 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 persons in the art without creative work are within the scope of protection of the present invention.

[0037] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second", "third", "fourth" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0038] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside", "outside", "inner side", "outer side", "below", "above", etc. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures.

[0039] In existing counter-rotating compressors, the blades are usually connected to the hub through a tongue and groove, and the tip clearance only exists between the blade tip and the casing, which will cause a tip leakage problem. As the compressor speed increases, the leakage flow continues to develop at the blade tip position, which will lead to a decrease in the single-stage efficiency of the compressor, causing overall instability of the machine, and even airflow reversal, reducing the overall performance of the compressor.

[0040] Based on the above technical problems, the present invention provides a compressor end wall leakage flow control device and method based on rotating wall control. The device controls the gap between the blade tip and the rotating casing and the gap between the blade root and the hub, thereby controlling the development of the end wall leakage flow and further improving the pressure ratio, efficiency and working stability of the impeller.

[0041] like Figure 1 , 5 As shown, the compressor end wall leakage flow control device based on rotating wall surface control involved in the present invention includes: a central shaft 11; a plurality of rotor assemblies, wherein the plurality of rotor assemblies are arranged in series on the central shaft 11 at intervals.

[0042] Furthermore, if Figure 2 , 6 As shown, the rotor assembly includes a forward rotor 1 and a reverse rotor 2, wherein the forward rotor 1 is sleeved on the central shaft 11, and the reverse rotor 2 is sleeved on the outside of the forward rotor 1, with a blade rotation space left between the two; the forward rotor 1 and the reverse rotor 2 rotate under the drive of the driving mechanism, and the rotation directions are opposite.

[0043] Furthermore, if Figure 7 As shown, the reversing rotor 2 includes a rotating casing 21 . The rotating casing 21 is an annular structure, and a plurality of reversing rotor blades 22 are evenly spaced along the circumferential inner wall surface of the rotating casing 21 .

[0044] Furthermore, if Figure 6 As shown, the forward-rotating rotor 1 comprises a forward-rotating rotor hub 12 , and a plurality of forward-rotating rotor blades 13 are evenly spaced on the circumferential outer wall surface of the forward-rotating rotor hub 12 .

[0045] Furthermore, if Figure 8 As shown, a plurality of the forward-rotating rotor blades 13 have gaps with the circumferential inner wall surface of the rotating casing 21 , and a plurality of the reverse-rotating rotor blades 22 have gaps with the circumferential outer wall surface of the forward-rotating rotor hub 12 .

[0046] Furthermore, if Figure 3 , 4 As shown, the number of the plurality of counter-rotating rotor blades 22 is the same as the number of the plurality of forward-rotating rotor blades 13, and they are arranged in a one-to-one correspondence.

[0047] Furthermore, if Figure 2 As shown, the plurality of the reverse rotor blades 22 and the plurality of the forward rotor blades 13 are all arc-shaped blades. Figure 1 As shown, the number of the rotor assemblies is ten.

[0048] The forward rotor 1 of the present invention controls the leakage flow by controlling the gap between the blade tip (the free end of the forward rotor blade is the blade tip) and the rotating casing 21, and the reverse rotor 2 controls the leakage flow by controlling the gap between the blade root (the free end of the reverse rotor blade 22 is the blade root) and the forward rotor hub 12, thereby suppressing the leakage flow from aggravating the leakage vortex, further weakening the mixing of the secondary flow and the mainstream, and reducing the flow loss and blockage caused by the leakage flow; the gap 3 between the forward rotor and the rotating casing and the gap 4 between the reverse rotor and the hub alternate at the position of the blade root and the blade tip, so that the tip / root leakage flow inside each row of blades is supplemented by the power added by the downstream reverse rotating rotor when flowing to the downstream adjacent blade, thereby suppressing the leakage flow from further migrating and expanding along the radial and axial positions, and effectively reducing the impact on the compressor pressure ratio, efficiency and working margin.

[0049] A second aspect of the present invention provides a working method of a compressor end wall leakage flow control device based on rotating wall surface control, comprising the following steps:

[0050] The driving mechanism is started, and the rotor assembly rotates under the driving of the driving mechanism, and the forward rotor 1 and the reverse rotor 2 rotate in opposite directions;

[0051] The medium to be compressed enters the leakage flow control device of the compressor end wall, and the medium rotates driven by the forward-rotating rotor blades 13 in the first group of rotor assemblies. Part of the medium in the gap 3 between the forward-rotating rotor and the rotating casing flows downstream to the reverse rotor blades 22, and the kinetic energy is replenished by the work done by the blades. The medium rotates, and part of the medium that is not driven enters the next group of rotor assemblies through the gap 4 between the reverse rotor and the hub, repeating the rotation action of the first group of rotor assemblies. After the medium to be compressed flows through several rotor assemblies, most of the medium rotates, thereby reducing the flow loss and blockage caused by the leakage flow.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compressor end wall leakage flow control device based on rotating wall control, characterized in that: include: Central axis (11); A plurality of rotor assemblies, wherein the plurality of rotor assemblies are arranged in series at intervals on the central shaft (11); the rotor assembly comprises a forward rotor (1) and a reverse rotor (2), wherein the forward rotor (1) is sleeved on the central shaft (11), and the reverse rotor (2) is sleeved outside the forward rotor (1), and a blade rotation space is left between the two. The forward-rotating rotor (1) and the reverse-rotating rotor (2) rotate under the drive of a driving mechanism, and the rotation directions are opposite.

2. The compressor end wall leakage flow control device based on rotating wall surface control according to claim 1, characterized in that: The reversing rotor (2) comprises a rotating casing (21), the rotating casing (21) being an annular structure, and a plurality of reversing rotor blades (22) being evenly spaced along the circumferential inner wall surface of the rotating casing (21).

3. The compressor end wall leakage flow control device based on rotating wall surface control according to claim 2, characterized in that: The forward-rotating rotor (1) comprises a forward-rotating rotor hub (12), and a plurality of forward-rotating rotor blades (13) are evenly spaced on the circumferential outer wall surface of the forward-rotating rotor hub (12).

4. The compressor end wall leakage flow control device based on rotating wall surface control according to claim 3, characterized in that: A gap is left between the plurality of forward-rotating rotor blades (13) and the circumferential inner wall surface of the rotating casing (21).

5. The compressor end wall leakage flow control device based on rotating wall surface control according to claim 3, characterized in that: A gap is left between the plurality of counter-rotating rotor blades (22) and the circumferential outer wall surface of the forward-rotating rotor hub (12).

6. The compressor end wall leakage flow control device based on rotating wall surface control according to claim 3, characterized in that: The number of the plurality of counter-rotating rotor blades (22) is the same as the number of the plurality of forward-rotating rotor blades (13), and they are arranged in a one-to-one correspondence.

7. The compressor end wall leakage flow control device based on rotating wall surface control according to claim 3, characterized in that: The plurality of counter-rotating rotor blades (22) and the plurality of forward-rotating rotor blades (13) are all arc-shaped blades.

8. The compressor end wall leakage flow control device based on rotating wall surface control according to claim 1, characterized in that: The number of the rotor assemblies is ten.

9. A working method of a compressor end wall leakage flow control device based on rotating wall control, characterized in that: The steps include: The driving mechanism is started, and the rotor assembly rotates under the drive of the driving mechanism, and the forward-rotating rotor (1) and the reverse-rotating rotor (2) rotate in opposite directions; The medium to be compressed enters the compressor end wall leakage flow control device, and the medium rotates under the drive of the forward-rotating rotor blades (13) in the first rotor assembly. A portion of the medium located in the gap (3) between the forward-rotating rotor and the rotating casing flows downstream to the reverse-rotating rotor blades (22), and the kinetic energy is replenished by the blades doing work, and the medium rotates. A portion of the medium that is not driven enters the next rotor assembly through the gap (4) between the reverse rotor and the hub, and the rotation action of the first rotor assembly is repeated again. After the compressed medium flows through several rotor assemblies, most of the medium rotates, thereby reducing flow losses and blockages caused by leakage flow.

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