Centrifugal compressor

Abstract

The utility model relates to a centrifugal compressor which comprises a compressor casing, a centrifugal impeller, a radial diffuser, an axial diffuser and a flow guide diffuser, the centrifugal impeller, the radial diffuser and the axial diffuser are sequentially arranged in the compressor casing, the compressor casing is fixedly connected with the radial diffuser and the axial diffuser, and the flow guide diffuser is arranged in the compressor casing. The flow guide diffuser is arranged on one side of the axial diffuser and fixed to one end of the compressor casing. And the radial diffuser, the axial diffuser and the flow guide diffuser are communicated with one another. A three-stage diffusion structure of the radial diffuser, the axial diffuser and the flow guide diffuser is used, so that airflow guided out by the flow guide diffuser has high stability, and it can be guaranteed that the engine has stable and reliable performance under different working conditions; and various mounting forms such as sealing grooves and lap joint are adopted, so that airflow leakage in the diffuser is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of centrifugal compressors, in particular to a centrifugal compressor. Background Art

[0002] A centrifugal compressor is a common type of compressor and a common diffuser in gas turbines and aero engines. It uses a high-speed rotating impeller to accelerate and pressurize air, compress the air, increase the air flow rate and pressure, and provide sufficient air-fuel mixture for the combustion chamber, with characteristics such as small volume and high single-stage pressure ratio.

[0003] The relevant research work on diffusers at home and abroad mainly focuses on improving the aerodynamic layout, optimizing the air flow field at the inlet of the combustion chamber, etc., so that the engine is more easily organized for combustion, the combustion efficiency is improved, and the flow loss is reduced. The existing centrifugal compressor sets a diffuser to change the air flow direction, decelerate and expand the air flow, and achieve the effect of optimizing the air flow field at the inlet of the combustion chamber. However, when changing the angle of the air flow direction, the air flow output by the compressor is unstable, which in turn leads to the instability of the gas entering the combustion chamber, and thus affects the performance of the engine. Summary of the Utility Model

[0004] In order to solve the above technical problems, the utility model provides a centrifugal compressor, which includes a three-stage pressure-increasing structure of a radial diffuser, an axial diffuser, and a guide diffuser. While realizing the pressure increase of the gas, it ensures that the gas entering the combustion chamber has high stability, and can ensure that the engine has stable and reliable performance under different working conditions.

[0005] To achieve the above object, the utility model provides a centrifugal compressor, including: a compressor casing, a centrifugal impeller, a radial diffuser, an axial diffuser, and a guide diffuser. The centrifugal impeller, the radial diffuser, and the axial diffuser are sequentially arranged inside the compressor casing. The compressor casing is fixedly connected to the radial diffuser and the axial diffuser. The guide diffuser is arranged on one side of the axial diffuser and fixed at one end of the compressor casing; the radial diffuser, the axial diffuser, and the guide diffuser are connected and communicated with each other.

[0006] Further, the compressor casing includes an outer casing, an inner casing, and a fixing ring. The outer casing and the inner casing are connected. The fixing ring is sleeved on the lower end of the inner casing and is jointly fixed on the radial diffuser and the axial diffuser with the inner casing. A third sealing groove is arranged on the outer casing, and the third sealing groove is cooperatively installed with the axial diffuser. The outer casing is connected to the guide diffuser.

[0007] Further, a sealing strip is arranged on the outer casing, and the sealing strip is cooperatively installed with the first sealing groove and the second sealing groove on the inner casing.

[0008] Further, the guide vanes of the radial diffuser are vertically arranged relative to its own disk surface, the guide vanes of the axial diffuser and the flow guiding diffuser are vertically arranged relative to their own circumferential surfaces, and the guide vane angles of the radial diffuser, the axial diffuser and the flow guiding diffuser relative to the axis are within the same interval.

[0009] Further, the center of the disk surface of the axial diffuser disk body extends away from the flow guiding diffuser to form a first disk surface inclination angle.

[0010] Further, the center of the disk surface of the radial diffuser disk body extends away from the flow guiding diffuser to form a second disk surface inclination angle, and the angles of the first disk surface inclination angle and the second disk surface inclination angle are within the same interval.

[0011] Further, the outer casing and the flow guiding diffuser are overlapped, and flange holes are provided on the outer casing, mounting holes are provided on the flow guiding diffuser, the outer casing and the flow guiding diffuser are overlapped, a lapping platform is arranged around the edge of the flow guiding diffuser, the lapping platform extends towards the side close to the axial diffuser, the mounting holes are arranged on the lapping platform, a groove is arranged in a circle at the bottom surface of the outer casing, the flange holes are arranged in the groove, the depth of the groove is the same as the height of the lapping platform, and a connecting piece is passed through the flange holes and the mounting holes to connect the outer casing and the flow guiding diffuser.

[0012] Further, a high-pressure air bleeding pipeline is arranged inside the flow guiding diffuser, and the high-pressure air bleeding pipeline is connected with an external controller.

[0013] Further, the flow guiding diffuser includes a plurality of guide vane cascades, and the plurality of guide vane cascades are arranged distributed along the center of the flow guiding diffuser.

[0014] Further, some of the guide vane cascades are provided with ventilation holes, the ventilation holes communicate with the high-pressure air bleeding pipeline, and the thickness of the guide vane cascades provided with the ventilation holes is greater than the thickness of the guide vane cascades not provided with the ventilation holes.

[0015] The above technical solution of the present utility model has the following advantages compared with the prior art: By using a three-stage pressure increasing structure of a radial diffuser, an axial diffuser and a flow guiding diffuser, the air flow led out by the flow guiding diffuser has higher stability, which can ensure that the engine has stable and reliable performance under different working conditions; and a variety of installation forms such as a sealing groove and lapping are adopted to avoid air flow leakage in the diffuser. Description of the Drawings

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 is an exploded view of the structure of the centrifugal compressor of the present invention;

[0018] Figure 2 is a sectional view of the centrifugal compressor of the present invention;

[0019] Figure 3 is a partial schematic view of the connection position between the outer casing and the diffuser of the centrifugal compressor of the present invention;

[0020] Figure 4 is a sectional view of the diffuser of the centrifugal compressor of the present invention.

[0021] Explanation of the reference numerals in the drawings of the specification: outer casing - 1; sealing groove - 110; flange hole - 120; inner casing - 2; fixing ring - 3; centrifugal impeller - 4; radial diffuser - 5; axial diffuser - 6; diffuser - 7; mounting hole - 710; air extraction pipe - 720; guide vane cascade - 730. Specific Embodiments

[0022] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will make a detailed description of the specific embodiments of the present invention in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] In the following description, many specific details are set forth to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0024] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that excludes other embodiments.

[0025] The present utility model will be described in detail with reference to the schematic diagrams. When describing the embodiments of the present utility model, for the convenience of explanation, the cross-sectional views showing the device structure will be enlarged locally in a non-general proportion, and the schematic diagrams are only examples, which should not limit the scope of protection of the present utility model herein. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0026] At the same time, in the description of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "upper, lower, left, right, inner, and outer" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying

[0027] that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model. In addition, the terms "first, second, or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0028] Unless otherwise clearly defined and limited in the present utility model, the terms "installed, connected, and coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can also be a mechanical connection, an electrical connection, or a direct connection, and can also be indirectly connected through an intermediate medium, or can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0029] Embodiment 1

[0030] The following refers to Figures 1 to 4 Describe a centrifugal compressor according to an embodiment of the present utility model, including a compressor casing, a centrifugal impeller 4, a radial diffuser 5, an axial diffuser 6, and a guide diffuser 7. The centrifugal impeller 4, the radial diffuser 5, and the axial diffuser 6 are sequentially arranged inside the compressor casing. In this embodiment, referring to Figure 1 , the centrifugal impeller 4 is arranged at the leftmost end, the axial diffuser 6 is arranged at the rightmost end. The compressor casing is fixedly connected to the radial diffuser 5 and the axial diffuser 6. Specifically, bolts pass through the compressor casing and the main body of the radial diffuser 5 and extend into the axial diffuser 6 to achieve connection and fixation. The guide diffuser 7 is arranged on one side of the axial diffuser 6 and fixed at one end of the compressor casing. Specifically, the guide diffuser 7 closes the right side of the compressor casing. The centrifugal impeller 4 is arranged on the left side of the compressor casing, fixing the radial diffuser 5 and the axial diffuser 6 inside the compressor casing, and the radial diffuser 5, the axial diffuser 6, and the guide diffuser 7 are connected and communicated. The radial diffuser 5, the axial diffuser 6, and the guide diffuser 7 form a three-stage compression structure, where the outlet of each stage of the diffuser matches the inlet of the next stage to achieve the effect of mutual connection.

[0031] For the centrifugal compressor provided in this embodiment, gas enters the guide diffuser 7 from the centrifugal impeller 4 through the radial diffuser 5 and the axial diffuser 6. Due to the requirements for the airflow angle and stability of the gas entering the combustion chamber, both the radial diffuser 5 and the axial diffuser 6 not only need to compress the airflow but also change the airflow direction. However, due to the bleed air from the compressor casing and the change in the airflow direction, it is easy to cause unstable output gas of the axial diffuser 6. Therefore, a guide diffuser 7 is further connected to the right side of the compressor casing to further compress and rectify the output gas of the axial diffuser 6, ensuring the stability of the output airflow of the compressor without affecting the bleed air function of the compressor casing.

[0032] In one embodiment, referring to Figure 1 , the compressor casing includes an outer casing 1, an inner casing 2 and a fixing ring 3. The outer casing 1 and the inner casing 2 are connected. A third sealing groove 110 is provided on the outer casing 1. The outer casing 1 is cooperatively installed with the axial diffuser 6 through the third sealing groove 110. The outer casing 1 is connected to the guide diffuser 7, ensuring the sealing performance of the connection between the outer casing 1 and the guide diffuser 7 and preventing the gas compressed by the radial diffuser 5 and the axial diffuser 6 from leaking. The fixing ring 3 is sleeved on the lower end of the inner casing 2 and is jointly fixed with the inner casing 2 on the radial diffuser 5 and the axial diffuser 6. Specifically, the inner casing 2 fixes the positions of the radial diffuser 5 and the axial diffuser 6 through screws and the fixing ring 3. The fixing ring 3 is sleeved on the lower end of the inner casing 2, pressing down the lower end of the inner casing 2 to contact the radial diffuser 5, and then fixed by bolts. The bolts sequentially pass through the fixing rod 3, the inner casing 2, the radial diffuser 5 and the axial diffuser 6, ensuring the fixed installation of the radial diffuser 5 and the axial diffuser 6.

[0033] In one embodiment, a sealing strip is provided on the outer casing 1. The sealing strip on the outer casing 1 is cooperatively installed with the inner casing 2 through the first sealing groove 210 and the second sealing groove 220 on the inner casing 2. Specifically, elastic sealing rubber rings can also be provided in the first sealing groove 210 and the second sealing groove 220, ensuring the sealing performance of the connection between the outer casing 1 and the inner casing 2.

[0034] In one embodiment, the guide vanes of the radial diffuser 5 are arranged perpendicular to its own disk surface, and the guide vanes of the axial diffuser 6 and the guide vane diffuser 7 are arranged perpendicular to their own circumferential surfaces. Specifically, the guide vanes of the radial diffuser 5 are arranged radially, and the guide vanes of the axial diffuser 6 are arranged axially to change the direction of the airflow after compression. Moreover, the guide vane angles of the radial diffuser 5, the axial diffuser 6, and the guide vane diffuser 7 relative to the axis are within the same range. Specifically, the guide vane angle refers to the inclination of the relative guide vane with respect to the axis. The guide vane angles being within the same range indicates that the guide vane angles of the radial diffuser 5, the axial diffuser 6, and the guide vane diffuser 7 are similar, enabling the outlet of each stage of the diffuser to match the inlet of the next stage, and the guide vane angle of the next inlet to conform to the airflow angle of the previous outlet, facilitating the smooth progress of the airflow compression work.

[0035] In one embodiment, the center of the disk surface of the axial diffuser 6 extends away from the guide vane diffuser 7 to form a first disk surface inclination angle, such that the axial diffuser 6 forms an inclination angle extending towards the radial diffuser 5, getting closer to the radial diffuser 5, improving the compression effect, while increasing the thermal and cold deformation margin of the axial diffuser 6 and enhancing the assembly performance of the axial diffuser 6.

[0036] In one embodiment, the center of the disk surface of the radial diffuser 5 extends away from the guide vane diffuser 7 to form a second disk surface inclination angle, and the angles of the first disk surface inclination angle and the second disk surface inclination angle are within the same range, indicating that the angles of the first disk surface inclination angle and the second disk surface inclination angle are similar, bringing the radial diffuser 5 closer to the axial diffuser 6 and ensuring the stability of the gas compression work.

[0037] In one embodiment, referring to Figure 3 , there is an overlap between the outer casing 1 and the guide vane diffuser 7. A flange hole 120 is provided on the outer casing 1, and a mounting hole 710 is provided on the guide vane diffuser 7. There is an overlap between the outer casing 1 and the guide vane diffuser 7. Specifically, a lapping platform is provided around the edge of the guide vane diffuser 7, and the lapping platform extends towards the side close to the axial diffuser 6. The mounting hole 710 is provided on the lapping platform. A groove is provided in a circle at the bottom surface of the outer casing 1, and the flange hole 120 is provided in the groove. The depth of the groove is the same as the height of the lapping platform. A connecting piece is passed through the flange hole 120 and the mounting hole 710 to connect the outer casing 1 and the guide vane diffuser 7. During installation, the lapping platform of the guide vane diffuser 7 is inserted into the groove of the outer casing 1, making the outer wall of the lapping platform contact the inner wall of the groove of the outer casing 1. Since the lapping platform extends towards the side close to the axial diffuser 6, the height of the lapping platform is higher than the disk surface of the guide vane diffuser 7, thus further enhancing the sealing performance of the connection between the guide vane diffuser 7 and the outer casing 1.

[0038] In one embodiment, referring to Figure 4, a high-pressure air extraction pipeline 720 is provided inside the flow guiding diffuser 7, and the high-pressure air extraction pipeline 720 is connected to an external controller. Specifically, the external controller includes a starting motor control sensor, a fuel regulator, a parameter monitoring system, etc. The gas pressure after being compressed by the compressor is a key parameter for engine control and monitoring. The gas compressed by the compressor passes through the radial diffuser 5, and after the turning section, it reaches the axial diffuser 6 and is led out by the high-pressure air extraction pipeline 720. Pressure signals are provided by external accessories such as the starting motor control sensor, the fuel regulator, and the parameter monitoring system, which is convenient for controlling the engine operation and monitoring the pressure parameters.

[0039] In one embodiment, referring to Figure 1 and 4 , the flow guiding diffuser 7 at least includes a guide vane cascade 730. There are multiple guide vane cascades 730, which are arranged around the center of the flow guiding diffuser 7 to achieve the function of pressure increasing and flow guiding.

[0040] In one embodiment, some of the guide vane cascades 730 are provided with ventilation holes, and the ventilation holes communicate with the high-pressure air extraction pipeline 720 to ventilate the high-pressure air extraction pipeline 720. Specifically, the guide vane cascade 730 is designed with a thick vane type, and the thickness of the guide vane cascade 730 with ventilation holes is greater than that of the guide vane cascade 730 without ventilation holes, which not only meets the requirements of pressure increasing and flow guiding and organizing the flow field, but also ensures the requirement of structural strength.

[0041] Note that the above is only the preferred embodiment of the present invention and the applied technical principle. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A centrifugal compressor, characterized in that, Comprising: A compressor casing, a centrifugal impeller (4), a radial diffuser (5), an axial diffuser (6), and a guide vane diffuser (7). The centrifugal impeller (4), the radial diffuser (5), and the axial diffuser (6) are sequentially arranged inside the compressor casing. The compressor casing is fixedly connected to the radial diffuser (5) and the axial diffuser (6). The guide vane diffuser (7) is arranged on one side of the axial diffuser (6) and is fixed at one end of the compressor casing. The radial diffuser (5), the axial diffuser (6), and the guide vane diffuser (7) are in communication.

2. The centrifugal compressor according to claim 1, characterized in that, The compressor casing includes an outer casing (1), an inner casing (2), and a fixing ring (3). The outer casing (1) and the inner casing (2) are connected. The fixing ring (3) is sleeved on the lower end of the inner casing (2) and is jointly fixed to the radial diffuser (5) and the axial diffuser (6) with the inner casing (2). A third sealing groove (110) is provided on the outer casing (1), and the third sealing groove (110) is fitted and installed with the axial diffuser (6). The outer casing (1) is connected to the guide vane diffuser (7).

3. The centrifugal compressor according to claim 2, wherein A sealing strip is provided on the outer casing (1), and the sealing strip is fitted and installed with a first sealing groove (210) and a second sealing groove (220) on the inner casing (2).

4. The centrifugal compressor according to claim 1, wherein, The guide vanes of the radial diffuser (5) are vertically arranged relative to its own disk surface. The guide vanes of the axial diffuser (6) and the guide vane diffuser (7) are vertically arranged relative to their own circumferential surfaces, and the guide vane angles of the radial diffuser (5), the axial diffuser (6), and the guide vane diffuser (7) relative to the axis are in the same range.

5. The centrifugal compressor according to claim 1, characterized in that, The disk surface center of the axial diffuser (6) extends away from the guide vane diffuser (7) to form a first disk surface inclination angle.

6. The centrifugal compressor according to claim 5, characterized in that, The disk surface center of the radial diffuser (5) extends away from the guide vane diffuser (7) to form a second disk surface inclination angle, and the angles of the first disk surface inclination angle and the second disk surface inclination angle are in the same range.

7. The centrifugal compressor according to claim 2, characterized in that, The outer casing (1) and the guide vane diffuser (7) are overlapped. A flange hole (120) is provided on the outer casing (1), and a mounting hole (710) is provided on the guide vane diffuser (7). The outer casing (1) and the guide vane diffuser (7) are overlapped. A lapping platform is provided around the edge of the guide vane diffuser (7), and the lapping platform extends towards the side close to the axial diffuser (6). The mounting hole (710) is provided on the lapping platform. A groove is provided in a circle on the bottom surface of the outer casing (1), and the flange hole (120) is provided in the groove. The depth of the groove is the same as the height of the lapping platform. A connecting piece is passed through the flange hole (120) and the mounting hole (710) to connect the outer casing (1) and the guide vane diffuser (7).

8. The centrifugal compressor according to claim 1, characterized in that A high-pressure air bleeding pipeline (720) is provided inside the guide vane diffuser (7), and the high-pressure air bleeding pipeline (720) is connected to an external controller.

9. The centrifugal compressor according to claim 8, wherein, The flow deflector and diffuser (7) includes a plurality of guide vane cascades (730), and the plurality of guide vane cascades (730) are arranged along the center of the flow deflector and diffuser (7).

10. The centrifugal compressor according to claim 9, characterized in that, Some of the guide vane cascades (730) are provided with ventilation holes, the ventilation holes communicate with the high-pressure air bleed pipe (720), and the thickness of the guide vane cascade (730) provided with the ventilation holes is greater than the thickness of the guide vane cascade (730) not provided with the ventilation holes.

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