Centrifugal compressor arrangement

Abstract

Centrifugal compressor device relates to the technical field of supercharging device, including compressor volute, centrifugal impeller is rotatably installed in compressor volute, full circle sink groove is set up on the inner wall of compressor volute in cooperation with centrifugal impeller, metal thin wall between full circle sink groove and centrifugal impeller is fixed on the inner wall of compressor volute, and pressure cavity is formed between metal thin wall and full circle sink groove, and the outlet pipeline of compressor volute is communicated with pressure cavity through air guide pipeline.The application solves the difference of the blade tip gap after coating the soft coating in the traditional technology, and the insufficient bearing capacity of the rotor system during operation due to the vibration of the centrifugal compressor device foundation platform, which causes the problem of aggravating the wear of the rotor bearing system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of supercharging device, in particular to centrifugal compressor device. BACKGROUND

[0002] As a kind of general impeller machinery, centrifugal compressor plays a vital role in petrochemical industry, heavy machinery and transportation device, and its efficiency of converting driving energy into pressure energy and long-term operation reliability are the direction of long-term improvement and improvement.

[0003] Centrifugal compressor is generally composed of centrifugal impeller, compressor scroll case, bearing system and driving device, centrifugal impeller is connected to bearing system through rotating shaft, and then realizes its rotation through driving device (generally turbine or motor). Since centrifugal impeller is a high-speed rotating part, in order to make it rotate smoothly, the blade tip profile line must have a matching gap with the compressor shell, which is St. St must be large enough to ensure that the impeller does not rub against the compressor scroll case during operation, so as to ensure the stable and safe operation of the compressor device.

[0004] During the rotation of centrifugal impeller, fresh air is continuously sucked from the compressor inlet, and then the rotational mechanical energy is continuously converted into pressure energy of air during rotation. Due to the existence of St, the compressed air will leak from the gap between the top of the impeller and the compression shell during the continuous compression of the air, resulting in waste of compression energy and reduction of compressor efficiency. In order to solve this problem, the existing technology adopts the measure of applying soft coating on the matching position of compressor shell and impeller top. When the compressor impeller is running, the soft coating material will be scratched off during the rotation of the impeller top, so as to avoid damaging the blade.

[0005] With the use of existing technology, its shortcomings have also been gradually exposed, mainly as follows:

[0006] The existing soft coating technology cannot be restored after being scratched by the blade, so the tip clearance of the compressor impeller will inevitably exist even after coating the soft coating. In addition, after the centrifugal compressor blade scratches the soft coating, due to the fact that the rotor unbalance, actual size after processing and shaft motion characteristics of each compressor are not completely consistent, the use of this technology in batch production of compressors will cause the difference of tip clearance, thereby causing harm to the consistency of compressor performance.

[0007] In addition, the highest rotating speed of the existing centrifugal compressor can reach 100000rpm-300000rpm, and the radial supporting force and the axial supporting force are provided by the floating bearing and the thrust bearing respectively to maintain the stable operation of the rotor under the super-high rotating speed, but the bearing carrying capacity is insufficient during the operation of the rotor system due to the vibration of the foundation platform of the centrifugal compressor device, and the rotor bearing system is worn out, thereby reducing the reliability of the centrifugal compressor device.

[0008] Therefore, the prior art has the above-mentioned problems in actual use, and it is necessary to improve. SUMMARY

[0009] In view of the defects in the prior art, the present application solves the problem of the difference in the blade tip gap after coating the soft coating in the conventional technology, and the problem of the insufficient bearing carrying capacity during the operation of the rotor system due to the vibration of the foundation platform of the centrifugal compressor device, and the problem of the wear of the rotor bearing system.

[0010] To solve the above problems, the present application provides the following technical scheme:

[0011] The centrifugal compressor device comprises a compressor volute, a centrifugal impeller is rotatably installed in the compressor volute, a full-circle sunken groove is formed on the inner wall of the compressor volute in cooperation with the centrifugal impeller, a metal thin wall is fixedly connected to the inner wall of the compressor volute between the full-circle sunken groove and the centrifugal impeller, a pressure cavity is formed between the metal thin wall and the full-circle sunken groove, and the pressure cavity is connected to the compressor volute outlet pipeline through the gas guiding pipeline.

[0012] As an optimized scheme, the centrifugal impeller comprises a plurality of centrifugal blades arranged circumferentially, a wing segment is arranged at the blade tip of the centrifugal blade, and a wedge surface is arranged on the outer end surface of the wing segment.

[0013] As an optimized scheme, a wedge-shaped area is formed between each wedge surface and the metal thin wall, and the opening angle direction of the wedge-shaped area is the same as the tangential direction of the rotation of the centrifugal impeller.

[0014] As an optimized scheme, the circumferential width of the wing segment is 2-4 times the thickness of the blade tip of the centrifugal blade.

[0015] As an optimized scheme, the maximum radial width of the wedge-shaped area is 0.02-0.05mm.

[0016] As an optimized scheme, the thickness of the metal thin wall is 0.02-0.2mm.

[0017] As an optimization scheme, the metal thin wall comprises a plurality of metal thin wall axial segments arranged circumferentially, and a metal thin wall radial segment arranged in a cylindrical shape at one end of the plurality of metal thin wall axial segments.

[0018] As an optimization scheme, the metal thin wall axial segment is fixed on the compressor casing inlet segment through a thin wall pressing member.

[0019] As an optimization scheme, the metal thin wall radial segment is fixed on the compressor casing diffuser segment through a thin wall pressing member two.

[0020] As an optimization scheme, the compressor casing is provided with a channel communicating with the pressure cavity, the bleed air pipeline comprises a bleed air pipe one connected to the channel, the other end of the bleed air pipe one is connected with a bleed air pipe two through a bleed air hose, and the compressor casing outlet pipeline is provided with a channel connected with the bleed air pipe two.

[0021] As an optimization scheme, the full-circumferential groove covers the centrifugal blade tip arc in the radial and axial directions.

[0022] As an optimization scheme, the impeller back disc gap of the centrifugal impeller is connected with the centrifugal impeller outlet segment.

[0023] Compared with the prior art, the beneficial effects of the present application are:

[0024] The pressure cavity is formed between the compressor casing and the metal thin wall, and the pressure cavity is connected with the compressor casing outlet pipeline, so that the air pressure in the pressure cavity is higher than the air pressure in the centrifugal impeller flow passage, so that the metal thin wall can always be pressed on the top of the wedge-shaped surface; the centrifugal impeller rotates at high speed under the drive of the driving device, the wedge-shaped area at the top of the centrifugal blade extrudes air, so that the air pressure of the wedge-shaped area is greatly improved, so that the metal thin wall and the wedge-shaped surface are separated, that is, a very small air film gap is formed between the two; since the metal thin wall is thin, it has good elastic deformation capacity, so that the metal thin wall can always maintain good self-adapting ability, that is, during the operation of the centrifugal impeller, the top of the centrifugal blade can always maintain a very small gap state, so that the leakage amount of air flow from the top of the centrifugal blade can be greatly reduced, thereby significantly improving the efficiency of the centrifugal compressor.

[0025] The centrifugal impeller continuously pressurizes airflow in the working process, the back disc gap of the impeller is communicated with the outlet section of the centrifugal impeller, therefore the average pressure in the back disc gap of the impeller is greater than the average pressure in the flow passage of the centrifugal impeller, thus the centrifugal impeller generates an axial force towards the inlet of the compressor; the wedge-shaped area at the top of the centrifugal blade of the device forms a high-pressure gas film in the running process, which separates the metal thin wall from the top of the centrifugal blade, and also generates an acting force on the top of the centrifugal blade; in the working section of the centrifugal impeller, each top of the centrifugal blade generates an axial force in the opposite direction of the inlet of the compressor under the action of the gas pressure in the wedge-shaped area, thus a part of the axial force generated by the centrifugal impeller in the running process is balanced, the load of the thrust bearing is reduced, and the service life of the thrust bearing is improved; in the guide section of the centrifugal impeller, each top of the centrifugal blade generates a centripetal force under the action of the gas pressure in the wedge-shaped area, thus the stability of the centrifugal compressor rotor in the running process is improved, and the service life of the floating bearing is improved.

[0026] The centrifugal compressor device has the characteristics of simple structure, convenient implementation and low cost, can effectively solve the problem of low efficiency of the centrifugal compressor device caused by large leakage flow in the top gap of the centrifugal impeller, and can also provide axial force and radial force for the centrifugal impeller, improve the load of the thrust bearing and the movement stability of the centrifugal compressor rotor respectively, and further improve the service life of the thrust bearing and the floating bearing. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual proportion.

[0028] Figure 1 is a structural schematic diagram of the present application;

[0029] Figure 2 is a structural schematic diagram of the metal thin wall of the present application;

[0030] Figure 3 is a structural schematic diagram of the wing section of the present application;

[0031] Figure 4 is a force schematic diagram of the centrifugal compressor rotor of the present application;

[0032] Figure 5 is a structural schematic diagram of the outside of the present application;

[0033] Figure 6 is Figure 1 is an enlarged schematic diagram of part A in the above figure;

[0034] Figure 7 As Figure 3 The enlarged structural schematic diagram of part B in the middle;

[0035] Figure 8 As Figure 3 The dynamic schematic diagram of part B in the middle.

[0036] In the figure: 1 - centrifugal compressor; 101 - compressor inlet; 102 - centrifugal compressor rotor; 2 - bearing system; 201 - thrust bearing; 202 - floating bearing; 3 - driving device; 5 - centrifugal impeller; 501 - centrifugal blade; 502 - centrifugal blade top; 503 - wing section; 504 - wedge surface; 505 - wedge surface top; 506 - centrifugal impeller flow passage; 507 - impeller back disc gap; 508 - centrifugal impeller outlet section; 509 - centrifugal impeller working section; 510 - centrifugal impeller guide section; 6 - bleed air pipeline; 7 - compressor volute; 701 - full circle sink groove; 702 - compressor volute inlet section; 703 - compressor volute diffuser section; 704 - compressor volute outlet pipeline; 8 - metal thin wall; 801 - metal thin wall axial section; 802 - metal thin wall radial section; 9 - bleed air pipe one; 10 - bleed air pipe two; 11 - thin wall compression part one; 12 - thin wall compression part two; 13 - pressure cavity; 14 - bleed air hose; 15 - wedge area. DETAILED DESCRIPTION

[0037] The embodiments of the technical scheme of the present application will be described in detail below in combination with the drawings. The following embodiments are only used to more clearly illustrate the technical scheme of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0038] As Figures 1 to 8 shown, the centrifugal compressor device, including centrifugal compressor 1, bearing system 2 and driving device 3, centrifugal compressor 1 including compressor volute 7, centrifugal impeller 5 and bleed air pipeline 6.

[0039] The centrifugal impeller 5 is rotatably arranged in the compressor volute 7, and the centrifugal impeller 5 can rotate at high speed under the support of the bearing system 2 and under the driving of the driving device 3.

[0040] The centrifugal impeller 5 is rotatably arranged in the compressor volute 7, and the centrifugal impeller 5 can rotate at high speed under the support of the bearing system 2 and under the driving of the driving device 3.

[0041] The centrifugal impeller 5 comprises a plurality of circumferentially arranged centrifugal blades 501, and the centrifugal blade 501 is provided with a wing segment 503 at the blade top.

[0042] Each wedge area 15 is formed between the wedge surface 504 and the metal thin wall 8, and the opening angle direction of the wedge area 15 is the same as the tangential direction of the rotation of the centrifugal impeller 5.

[0043] The circumferential width L of the wing segment 503 is 2-4 times the thickness t of the centrifugal blade 501.

[0044] The maximum radial width h of the wedge area 15 is 0.02-0.05mm.

[0045] The thickness S of the metal thin wall 8 is 0.02-0.2mm.

[0046] The metal thin wall 8 comprises a plurality of circumferentially arranged metal thin wall axial segments 801 and a cylindrical metal thin wall radial segment 802 connected to one end of the plurality of metal thin wall axial segments 801.

[0047] The metal thin wall axial segment 801 is fixed to the compressor casing inlet section 702 by the thin wall pressing member 11.

[0048] The metal thin wall radial segment 802 is fixed to the compressor casing diffuser section 703 by the thin wall pressing member 12.

[0049] The compressor casing 7 is provided with a channel communicating with the pressure cavity 13, and the bleed air pipeline 6 comprises a bleed air pipe 9 connected to the channel, and the other end of the bleed air pipe 9 is connected to a bleed air pipe 10 through a bleed air hose 14.

[0050] The full-circumferential sink groove 701 covers the centrifugal blade 501 blade top arc in the radial and axial directions.

[0051] The impeller back disc gap 507 of the centrifugal impeller 5 is connected to the centrifugal impeller outlet section 508.

[0052] The working principle of the device is as follows:

[0053] The pressure cavity 13 is formed between the compressor casing 7 and the metal thin wall 8, and is connected with the compressor casing outlet pipe 704, so that the air pressure in the pressure cavity 13 is higher than that in the centrifugal impeller flow channel 506, and the metal thin wall 8 can always be pressed on the wedge top 505; the centrifugal impeller 5 rotates at high speed under the driving of the driving device 3, the wedge area 15 of the centrifugal blade top 502 extrudes air, so that the air pressure of the wedge area 15 is greatly increased, and the metal thin wall 8 is separated from the wedge surface 504, that is, a very small air film gap is formed between the metal thin wall 8 and the wedge surface 504; since the metal thin wall 8 is thin and has good elastic deformation capacity, the metal thin wall 8 can always have good self-adapting capacity, that is, the centrifugal blade top 502 can always keep a very small gap during the operation of the centrifugal impeller 5, so that the air leakage from the centrifugal blade top 502 can be greatly reduced, and the efficiency of the centrifugal compressor 1 is greatly improved.

[0054] The centrifugal impeller 5 pressurizes air flow during operation, the impeller back disc gap 507 is communicated with the centrifugal impeller outlet section 508, so that the average pressure P2 in the impeller back disc gap 507 is greater than the average pressure P1 in the centrifugal impeller flow channel 506, and the centrifugal impeller 5 generates an axial force F1 towards the compressor inlet 101; the wedge area 15 of the centrifugal blade top 502 of the device forms a high-pressure air film during operation, which separates the metal thin wall 8 from the centrifugal blade top 502, and also generates a force on the centrifugal blade top 502; in the centrifugal impeller working section 509, each centrifugal blade top 502 generates an axial force F2_a in the opposite direction of the compressor inlet 101 under the action of the pressure of the wedge area 15, so that a part of the axial force of the centrifugal impeller 5 during operation is balanced, the load F3 (F1-NxF2_a, N is the number of blades of the centrifugal impeller 5) of the thrust bearing 201 is reduced, and the service life of the thrust bearing 201 is improved; in the centrifugal impeller guide section 510, each centrifugal blade top 502 generates a centripetal force F2_r under the action of the pressure of the wedge area 15, so that the stability of the centrifugal compressor rotor 102 during operation is improved, and the service life of the floating bearing 202 is improved.

[0055] The present application has the characteristics of simple structure, convenient implementation and low cost, and can effectively solve the problem of large centrifugal impeller 5 top gap leakage flow in the centrifugal compressor 1 device, which leads to low efficiency of the compressor device, and can also provide axial force and radial force for the centrifugal impeller 5, improve the load of the thrust bearing 201 and the stability of the centrifugal compressor rotor 102, and further improve the service life of the thrust bearing 201 and the floating bearing 202.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application.

Claims

1. A centrifugal compressor device, characterized in that: The compressor includes a compressor volute (7), in which a centrifugal impeller (5) is rotatably mounted. A full-circumferential groove (701) is formed on the inner wall of the compressor volute (7) that mates with the centrifugal impeller (5). A thin metal wall (8) is fixed to the inner wall of the compressor volute (7) between the full-circumferential groove (701) and the centrifugal impeller (5), and a pressure chamber (13) is formed between the thin metal wall (8) and the full-circumferential groove (701). The pressure chamber (13) is connected to the compressor volute outlet pipe (704) through an air intake pipe (6). The centrifugal impeller (5) includes a plurality of centrifugal blades (501) arranged circumferentially. The centrifugal blades (501) have a blade section (503) at the tip and a wedge-shaped surface (504) on the outer end face of the blade section (503). Each of the wedge-shaped surfaces (504) forms a wedge-shaped region (15) between itself and the thin metal wall (8). The angular direction of the wedge-shaped region (15) is the same as the tangential direction of the rotation of the centrifugal impeller (5). The thin metal wall (8) includes a plurality of axial sections (801) of thin metal wall arranged circumferentially, and a radial section (802) of thin metal wall arranged in a cylindrical shape connected to one end of the plurality of axial sections (801) of thin metal wall.

2. The centrifugal compressor device according to claim 1, characterized in that: The circumferential width of the airfoil (503) is 2-4 times the tip thickness of the centrifugal blade (501).

3. The centrifugal compressor device according to claim 1, characterized in that: The maximum radial width of the wedge-shaped region (15) is 0.02-0.05 mm.

4. The centrifugal compressor device according to claim 1, characterized in that: The thickness of the metal thin wall (8) is 0.02-0.2 mm.

5. The centrifugal compressor device according to claim 1, characterized in that: The thin-walled axial section (801) is fixed to the compressor vortex inlet section (702) by a thin-walled clamping member (11).

6. The centrifugal compressor device according to claim 1, characterized in that: The thin-walled radial section (802) is fixed to the compressor vortex diffuser section (703) by a thin-walled clamping member (12).

7. The centrifugal compressor device according to claim 1, characterized in that: The compressor volute (7) has a channel that connects to the pressure chamber (13). The air intake pipe (6) includes an air intake pipe one (9) connected to the channel. The other end of the air intake pipe one (9) is connected to an air intake pipe two (10) through an air intake hose (14). The compressor volute outlet pipe (704) has a channel that connects to the air intake pipe two (10).

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