High-power centrifugal gas compressor adopting dynamic and static pressure gas foil bearings and operation method

Abstract

The invention provides a high-power centrifugal gas compressor adopting dynamic and static pressure gas foil bearings and an operation method, and belongs to the field of compressors. The problems that an existing bearing is complex in structure, large in installation size and poor in stability during high-speed operation are solved. The rotor magnetic steel is supported to rotate through dynamic pressure generated by gas when the rotor magnetic steel rotates so as to provide lubrication, then the rotor magnetic steel rotates to synchronously drive the impeller to rotate, and generated high-pressure gas is introduced into the dynamic and static pressure foil radial bearing and the dynamic and static pressure foil thrust bearing through the gas branch so as to provide static pressure for the bearings. According to the gas compressor, an extra gas supply system does not need to continuously supply gas to the dynamic and static pressure gas foil bearing, but the high-pressure gas output part generated by the gas compressor is used for supplying the gas to the dynamic and static pressure bearing of the gas compressor, and compared with a dynamic and static pressure gas foil bearing type compressor, under the condition that normal operation of the compressor is guaranteed, the high-pressure gas can be continuously supplied to the dynamic and static pressure gas foil bearing; and the space is effectively saved.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and in particular to a high-power centrifugal gas compressor using dynamic and static pressure gas foil bearings and an operating method thereof. Background Art

[0002] Centrifugal compressors were developed on the basis of ventilators. In the early 20th century, centrifugal compressors with a pressure ratio of 4.5 appeared. Since the 1950s, the centrifugal compressor manufacturing industry has developed. In 1963, the United States produced the first 14.7 MPa high-pressure centrifugal compressor for a synthetic ammonia plant. It used a barrel casing instead of a horizontally split casing, also known as a barrel compressor, which can withstand pressures above 10 MPa. In the 1970s, the United States, Italy and the Federal Republic of Germany successively produced 60-70 MPa high-pressure barrel compressors with a barrel wall thickness of 280 mm. In the early 1980s, the exhaust pressure had reached 80 MPa. The speed of a centrifugal compressor is generally more than several thousand rpm, and some have reached more than 25,000 rpm. The required power can reach tens of thousands of kilowatts, and the flow rate has reached 10,000 cubic meters per minute.

[0003] Centrifugal compressors require bearings to be safe and reliable, stable in operation, good in vibration resistance, and long in service life. In order to better meet these requirements, radial bearings and thrust bearings are constantly being developed and improved. However, the oil-lubricated bearings used in traditional gas compressors often have complex structures, require large installation dimensions, and have poor stability when running at high speeds. Summary of the invention

[0004] The technical problems to be solved by the present invention are:

[0005] In order to solve the problems of existing bearings having complex structures, large installation dimensions and poor stability during high-speed operation.

[0006] The present invention adopts the following technical solutions to solve the above technical problems:

[0007] The present invention provides a high-power centrifugal gas compressor using a dynamic and static pressure gas foil bearing, comprising a shell and a rotor magnet inside the shell, wherein a stator is arranged outside the rotor magnet, and a dynamic and static pressure foil radial bearing, a dynamic and static pressure foil thrust bearing, an impeller and a volute are arranged in sequence on one side of the rotor magnet, and a rotor thrust plate is arranged inside the dynamic and static pressure foil thrust bearing; a dynamic and static pressure foil radial bearing, an impeller and a volute are arranged in sequence on the other side of the rotor magnet, and the impeller and the volute are both located on the outside of the two ends of the shell, and also include a gas branch, one end of the gas branch is connected to the outlet pipeline, and the other end of the gas branch is connected to the dynamic and static pressure foil thrust bearing and the dynamic and static pressure foil radial bearing.

[0008] Furthermore, the dynamic and static pressure foil thrust bearing includes a top foil, a raised foil and a substrate arranged in sequence, the top foil and the substrate are both annular structures, and the top foil, the raised foil and the substrate are all provided with air vents. The air vents of the top foil are connected to a metal air duct, which passes through the limiting holes on the raised foil and the substrate and then extends out of the substrate.

[0009] Furthermore, the rotor thrust plate is arranged between the raised foil and the base plate.

[0010] Furthermore, there are a plurality of raised foils, which are evenly distributed between the top foil and the substrate.

[0011] Furthermore, each of the raised foils has the same shape, and each of the raised foils is provided with a plurality of evenly distributed strip-shaped protrusions.

[0012] Furthermore, the dynamic and static pressure foil radial bearing includes a corrugated foil, a top foil and a bearing sleeve, the corrugated foil is clamped between the top foil and the bearing sleeve, and corresponding positions on the corrugated foil, the top foil and the bearing sleeve are all circumferentially evenly distributed with air supply holes, and the air supply pipe passes through the bearing sleeve, the corrugated foil and the top foil in sequence and then ventilates the rotor magnet in the top foil.

[0013] Furthermore, a wedge-shaped groove is provided at the opening of the top foil, and the opening of the corrugated foil is clamped in the wedge-shaped groove of the top foil, thereby fixing the corrugated foil.

[0014] Furthermore, the corrugated foil and the bearing sleeve are both provided with limiting grooves, the positions of the limiting grooves match the positions of the air supply pipes and are axially provided at the ends of the corrugated foil and the bearing sleeve.

[0015] A method for operating a high-power centrifugal gas compressor using a dynamic and static pressure gas foil bearing comprises the following steps: when the gas compressor is started, there is no high-pressure gas in the dynamic and static pressure foil radial bearing and the dynamic and static pressure foil thrust bearing, and the rotor magnet is supported to rotate and lubrication is provided by the dynamic pressure generated by the gas when the rotor magnet rotates; then the rotor magnet rotates synchronously to drive the impeller to rotate, and the generated high-pressure gas passes through a gas branch into the dynamic and static pressure foil radial bearing and the dynamic and static pressure foil thrust bearing to provide static pressure for the bearings; in this state, the bearings provide the supporting force and lubrication required for the rotation of the rotor magnet together with the static pressure of the high-pressure gas generated by the compressed gas of the gas compressor itself and the dynamic pressure generated by the rotation of the rotor magnet.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention discloses a high-power centrifugal gas compressor and an operating method using dynamic and static pressure gas foil bearings. The dynamic pressure generated by the gas when the rotor magnet rotates supports the rotor magnet to rotate and provide lubrication. Subsequently, the rotor magnet rotates synchronously to drive the impeller to rotate. The generated high-pressure gas passes through the gas branch to enter the dynamic and static pressure foil radial bearing and the dynamic and static pressure foil thrust bearing to provide static pressure for the bearing. The present invention no longer requires an additional air supply system to continuously supply air to the dynamic and static pressure gas foil bearings, but relies on the high-pressure gas generated by the gas compressor itself to be exported to supply air to the dynamic and static pressure bearings of the gas compressor. Since an additional air supply system is no longer required, the structure of the two-stage centrifugal gas compressor with dynamic and static pressure gas foil bearings is unchanged compared to the dynamic pressure gas foil bearing compressor, and the space occupied is basically the same. Compared with the dynamic and static pressure gas foil bearing compressor, the space is effectively saved while ensuring its normal operation, and the operation stability and work efficiency are improved compared to the dynamic pressure or static pressure gas foil bearing compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A gas flow diagram of an operation method of a high-power centrifugal gas compressor using a dynamic and static pressure gas foil bearing in an embodiment of the present invention;

[0019] Figure 2 It is a structural diagram of a high-power centrifugal gas compressor using dynamic and static pressure gas foil bearings in an embodiment of the present invention;

[0020] Figure 3 Schematic diagram of the three-dimensional structure of the dynamic and static pressure foil thrust bearing in the embodiment of the present invention Figure 1 ;

[0021] Figure 4 Schematic diagram of the three-dimensional structure of the dynamic and static pressure foil thrust bearing in the embodiment of the present invention Figure 2 ;

[0022] Figure 5 The structure of the dynamic and static pressure foil radial bearing in the embodiment of the present invention is shown in FIG. Figure 1 ;

[0023] Figure 6 The structure of the dynamic and static pressure foil radial bearing in the embodiment of the present invention is shown in FIG. Figure 2 .

[0024] Description of reference numerals:

[0025] 1. Impeller; 2. Dynamic and static pressure foil thrust bearing; 3. Rotor thrust plate; 4. Dynamic and static pressure foil radial bearing; 5. Rotor magnet; 7. Volute; 8. Gas branch; 9. Gas outlet pipeline; 201. Top foil; 202. Raised foil; 203. Base plate; 204. Air guide tube; 205. Air vent; 401. Corrugated foil; 402. Top foil; 403. Bearing sleeve; 404. Air supply pipe; 405. Air supply hole; 406. Limiting groove. DETAILED DESCRIPTION

[0026] In the description of the present invention, it should be noted that the terminology nouns in the various embodiments, such as "up", "down", "front", "back", "left", "right", etc., which indicate directions, are only for simplifying the description of the positional relationship based on the drawings in the specification, and do not mean that the referred elements and devices must be operated according to the specific directions and defined operations and methods and structures in the specification. Such directional nouns do not constitute a limitation on the present invention.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0028] Specific implementation plan 1: Combine Figures 1 to 6 As shown, the present invention provides a high-power centrifugal gas compressor using a dynamic and static pressure gas foil bearing, including a shell and a rotor magnet 5 inside the shell, the outside of the rotor magnet 5 is provided with a stator, one side of the rotor magnet 5 is provided with a dynamic and static pressure foil radial bearing 4, a dynamic and static pressure foil thrust bearing 2, an impeller 1 and a volute 7 in sequence, and the dynamic and static pressure foil thrust bearing 2 is provided with a rotor thrust plate 3; the other side of the rotor magnet 5 is provided with a dynamic and static pressure foil radial bearing 4, an impeller 1 and a volute 7 in sequence, the impeller 1 and the volute 7 are both located on the outside of the two ends of the shell, one end of the gas branch 8 is connected to the outlet pipeline 9, and the other end of the gas branch 8 is connected to the dynamic and static pressure foil thrust bearing 2 and the dynamic and static pressure foil radial bearing 4.

[0029] Preferably, the dynamic and static pressure foil thrust bearing 2 includes a top foil 201, a protruding foil 202 and a substrate 203 which are arranged in sequence, and the top foil 201 and the substrate 203 are both annular structures, and the top foil 201, the protruding foil 202 and the substrate 203 are all provided with air vents 205, and the air vents 205 of the top foil 201 are connected with a metal air guide pipe 204, and the air guide pipe 204 passes through the limiting holes 205 on the protruding foil 202 and the substrate 203 and then extends out of the substrate 203, and is used to be connected to the air supply pipeline of the gas branch 8 of the gas compressor, so as to provide high-pressure gas between the surface of the top foil 201 of the thrust bearing and the surface of the rotor thrust plate 3.

[0030] The rotor thrust plate 3 is arranged between the protruding foil 202 and the base plate 203. When the gas compressor is not working, the top foil 201 surfaces of the two dynamic and static pressure foil thrust bearings 2 are in contact with the surfaces on both sides of the rotor thrust plate 3.

[0031] There are a plurality of raised foils 202 , which are evenly distributed between the top foil 201 and the substrate 203 . Each raised foil 202 has the same shape, and each raised foil 202 is provided with a plurality of evenly distributed strip-shaped protrusions.

[0032] Preferably, the dynamic and static pressure foil radial bearing 4 includes a corrugated foil 401, a top foil 402 and a bearing sleeve 403, the corrugated foil 401 is sandwiched between the top foil 402 and the bearing sleeve 403, the opening of the top foil 402 is provided with a wedge-shaped groove, and the opening of the corrugated foil 401 is clamped in the wedge-shaped groove of the top foil 402 to play a fixing role; the corrugated foil 401, the top foil 402 and the corresponding positions on the bearing sleeve 403 are all circumferentially evenly distributed with air supply holes 405, and the air supply pipe 404 passes through the bearing sleeve 403, the corrugated foil 401 and the top foil 402 in sequence and then ventilates the rotor magnet 5 in the top foil 402.

[0033] The corrugated foil 401 and the bearing sleeve 403 are both provided with limiting grooves 406, the position of which matches the position of the air supply pipe 404 and is axially provided at the ends of the corrugated foil 401 and the bearing sleeve 403. The air supply pipe 404 in the dynamic and static pressure foil radial bearing 4 passes the high-pressure gas from the gas branch 8 into the surface of the top foil 402 of the dynamic and static pressure foil radial bearing 4 and the surface of the shaft section in the bearing, thereby generating gas static pressure.

[0034] Specific implementation plan 2: Combined Figures 1 to 6 As shown, the present invention provides an operation method of a high-power centrifugal gas compressor using a dynamic and static pressure gas foil bearing, comprising the following steps:

[0035] When the gas compressor is started, there is no high-pressure gas in the dynamic and static pressure foil radial bearing 4 and the dynamic and static pressure foil thrust bearing 2, and the rotor magnet 5 is supported and lubricated by the dynamic pressure generated by the gas when the rotor magnet 5 rotates; then, the impeller 1 is synchronously driven to rotate due to the rotation of the rotor magnet 5, and the high-pressure gas generated passes through the gas branch 8 into the dynamic and static pressure foil radial bearing 4 and the dynamic and static pressure foil thrust bearing 2, providing static pressure for the bearings; in this state, the bearings are provided with the supporting force and lubrication required for the rotation of the rotor magnet 5 by the static pressure of the high-pressure gas generated by the compressed gas of the gas compressor itself and the dynamic pressure generated by the rotation of the rotor magnet 5.

[0036] The other combinations and connection relationships of this embodiment are the same as those of the first embodiment.

[0037] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A high-power centrifugal gas compressor using dynamic and static pressure gas foil bearings, characterized in that: The invention comprises a housing and a rotor magnet (5) inside the housing, wherein a stator is arranged outside the rotor magnet (5), and a dynamic and static pressure foil radial bearing (4), a dynamic and static pressure foil thrust bearing (2), an impeller (1) and a volute (7) are arranged in sequence on one side of the rotor magnet (5), and a rotor thrust disk (3) is arranged inside the dynamic and static pressure foil thrust bearing (2); and a dynamic and static pressure foil radial bearing (4), an impeller (1) and a volute (7) are arranged in sequence on the other side of the rotor magnet (5), and the impeller (1) and the volute (7) are both located outside the two ends of the housing, and also comprises a gas branch (8), one end of the gas branch (8) is connected to an outlet pipeline (9), and the other end of the gas branch (8) is connected to the dynamic and static pressure foil thrust bearing (2) and the dynamic and static pressure foil radial bearing (4).

2. A high-power centrifugal gas compressor using dynamic and static pressure gas foil bearings according to claim 1, characterized in that: The dynamic and static pressure foil thrust bearing (2) comprises a top foil (201), a protruding foil (202) and a base plate (203) which are arranged in sequence, wherein the top foil (201) and the base plate (203) are both annular structures, and air vents (205) are provided on the top foil (201), the protruding foil (202) and the base plate (203). The air vents (205) of the top foil (201) are connected to a metal air guide tube (204), and the air guide tube (204) passes through the limiting holes (205) on the protruding foil (202) and the base plate (203) and then extends out of the base plate (203).

3. A high-power centrifugal gas compressor using dynamic and static pressure gas foil bearings according to claim 2, characterized in that: The rotor thrust plate (3) is arranged between the raised foil (202) and the base plate (203).

4. A high-power centrifugal gas compressor using dynamic and static pressure gas foil bearings according to claim 3, characterized in that: The number of the raised foils (202) is plural and they are evenly distributed between the top foil (201) and the substrate (203).

5. A high-power centrifugal gas compressor using dynamic and static pressure gas foil bearings according to claim 4, characterized in that: Each of the protruding foils (202) has the same shape, and each of the protruding foils (202) is provided with a plurality of evenly distributed strip-shaped protrusions.

6. A high-power centrifugal gas compressor using dynamic and static pressure gas foil bearings according to claim 1, characterized in that: The dynamic and static pressure foil radial bearing (4) comprises a corrugated foil (401), a top foil (402) and a bearing sleeve (403); the corrugated foil (401) is sandwiched between the top foil (402) and the bearing sleeve (403); corresponding positions on the corrugated foil (401), the top foil (402) and the bearing sleeve (403) are uniformly distributed with air supply holes (405) in the circumferential direction; the air supply pipe (404) passes through the bearing sleeve (403), the corrugated foil (401) and the top foil (402) in sequence and then ventilates the rotor magnet (5) in the top foil (402).

7. A high-power centrifugal gas compressor using dynamic and static pressure gas foil bearings according to claim 6, characterized in that: A wedge-shaped groove is provided at the opening of the top foil (402), and the opening of the corrugated foil (401) is clamped in the wedge-shaped groove of the top foil (402), thereby fixing the corrugated foil (401).

8. A high-power centrifugal gas compressor using dynamic and static pressure gas foil bearings according to claim 7, characterized in that: The corrugated foil (401) and the bearing sleeve (403) are both provided with a limiting groove (406), the position of the limiting groove (406) matches the position of the air supply pipe (404) and is axially provided at the ends of the corrugated foil (401) and the bearing sleeve (403).

9. A method for operating a high-power centrifugal gas compressor using dynamic and static pressure gas foil bearings according to any of claims 1 to 8, characterized in that: The invention comprises the following steps: when the gas compressor is started, there is no high-pressure gas in the dynamic and static pressure foil radial bearing (4) and the dynamic and static pressure foil thrust bearing (2), and the dynamic pressure generated by the gas when the rotor magnet (5) rotates supports the rotation of the rotor magnet (5) and provides lubrication; then, the rotor magnet (5) rotates synchronously to drive the impeller (1) to rotate, and the generated high-pressure gas passes through the gas branch (8) into the dynamic and static pressure foil radial bearing (4) and the dynamic and static pressure foil thrust bearing (2), providing static pressure for the bearings; in this state, the bearings provide the supporting force and lubrication required for the rotation of the rotor magnet (5) together with the static pressure of the high-pressure gas generated by the compressed gas of the gas compressor itself and the dynamic pressure generated by the rotation of the rotor magnet (5).

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