Multi-stage compression magnetic suspension centrifugal compressor with independent rotating speed

Abstract

The utility model relates to the technical field of centrifugal refrigeration compressors, in particular to a multistage compression magnetic suspension centrifugal compressor with an independent rotating speed. The compressor comprises a flange plate, a first-stage motor and a second-stage motor, the first-stage motor and the second-stage motor operate independently, the two sides of the flange plate are fixedly connected to one end of the first-stage motor and one end of the second-stage motor, and the first-stage motor and the second-stage motor basically extend in the direction of a first straight line L1; a first-stage impeller and a second-stage impeller are respectively arranged in the first-stage motor and the second-stage motor, and the number of the first-stage impeller and the number of the second-stage impeller are respectively one or a plurality of the first-stage impeller and the second-stage impeller which are connected in series. According to the compressor, adjustment of different rotating speeds of the first-stage motor and the second-stage motor of the compressor can be achieved, adjustment of optimal inter-stage pressure of the compressor under the large pressure ratio is achieved, the optimal isentropic compression efficiency is achieved, and then the energy-saving effect is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of centrifugal refrigeration compressors, in particular to a multi-stage compression magnetic levitation centrifugal compressor with independent rotational speeds. Background Art

[0002] Magnetic levitation centrifugal compressors are often applied to refrigeration and heating equipment. A magnetic levitation centrifugal compressor includes a magnetic levitation motor, a centrifugal impeller, a volute, a magnetic floating bearing, a compressor housing, etc. The magnetic levitation motor mainly includes a housing, a stator disposed within the housing and fixedly connected to the housing, a motor rotor, a radial magnetic levitation bearing for supporting the rotation of the rotor, and an axial thrust bearing for maintaining the axial position of the rotor. The magnetic levitation motor further includes a protection bearing disposed within the housing, and the protection bearing is used to carry the stationary rotor to prevent the rotor from contacting the radial magnetic levitation bearing, thereby protecting the radial magnetic levitation bearing. When the magnetic levitation motor operates, the radial magnetic levitation bearing is energized to separate the rotor from the protection bearing and suspend it.

[0003] Currently, magnetic levitation centrifugal compressors are generally single-motor single-stage compression, single-motor two-stage compressors, or single-motor multi-stage compressors. One compressor motor stator drives one centrifugal impeller, two centrifugal impellers, or more centrifugal impellers. Among those with two centrifugal impellers, they are divided into two impellers in series or two impellers in horizontal opposed series. For example, the Chinese utility model patent with the application number CN202122639494.6 specifically describes the structure of a magnetic levitation centrifugal compressor.

[0004] The advantages of such single-rotor compressors are: relatively compact and simple structure, and the same rotational speed of a single motor. The disadvantages are: the rotational speeds of the high- and low-pressure stage impellers cannot be independently adjusted, and it is impossible to solve the adjustment of the compressor to achieve the optimal inter-stage pressure under a large pressure ratio and the optimal isentropic compression efficiency. Summary of the Utility Model

[0005] In order to solve the above technical problems, the purpose of the present utility model is to provide a multi-stage compression magnetic levitation centrifugal compressor with independent rotational speeds, which can realize different rotational speed adjustments of the first-stage and second-stage motors of the compressor, solve the adjustment of the compressor to achieve the optimal inter-stage pressure under a large pressure ratio, and achieve the optimal isentropic compression efficiency.

[0006] In order to achieve the above purpose, the present utility model adopts the following technical solutions:

[0007] A multi-stage compression magnetic levitation centrifugal compressor with independent rotational speeds, the compressor includes a flange and a first-stage motor and a second-stage motor that operate independently. One end of the first-stage motor and one end of the second-stage motor are respectively fixedly connected to both sides of the flange, and the first-stage motor and the second-stage motor are basically arranged along the direction of the first straight line L1.

[0008] Preferably, a first-stage volute is provided at one end of the first-stage motor away from the flange. A first-stage impeller is installed in the first-stage volute. One end of the first-stage impeller is connected to a first-stage rotor extending into the first-stage volute. A second-stage volute is provided at one end of the second-stage motor away from the flange. A second-stage impeller is installed in the second-stage volute. One end of the second-stage impeller is connected to a second-stage rotor extending into the second-stage volute. The blades of the first-stage impeller and the second-stage impeller face in opposite directions.

[0009] Preferably, at least two first-stage impellers are provided, which extend and are connected in series along the direction of the second straight line L2 to form a first impeller unit, and the first impeller unit is installed in the first-stage volute.

[0010] Preferably, at least two second-stage impellers are provided, which extend and are connected in series along the direction of the first straight line L1 to form a second impeller unit, and the second impeller unit is installed in the second-stage volute.

[0011] Preferably, the first-stage motor includes a first-stage motor cylinder, and a first-stage rotor, a first-stage stator, and a first-stage magnetic bearing provided in the first-stage motor cylinder. The first-stage rotor is axially arranged in the first-stage motor cylinder along the direction of the first straight line L1. The first-stage stator is installed in the middle of the first-stage rotor. Two sets of first-stage magnetic bearings are provided and are respectively mounted on both ends of the first-stage rotor.

[0012] Preferably, the first-stage motor further includes a first-stage thrust bearing for stabilizing the first-stage rotor. The first-stage thrust bearing is sleeved on the first-stage rotor and is located between the flange and the first-stage magnetic bearing.

[0013] Preferably, the second-stage motor includes a second-stage motor cylinder, and a second-stage rotor, a second-stage stator, and a second-stage magnetic bearing provided in the second-stage motor cylinder. The second-stage rotor is axially arranged in the second-stage motor cylinder along the direction of the first straight line L1. The second-stage stator is installed in the middle of the second-stage rotor. Two sets of second-stage magnetic bearings are provided and are respectively mounted on both ends of the second-stage rotor.

[0014] Preferably, the second-stage motor further includes a second-stage thrust bearing for stabilizing the second-stage rotor. The second-stage thrust bearing is sleeved on the second-stage rotor and is located between the flange and the second-stage magnetic bearing.

[0015] Preferably, a medium-pressure connecting pipe for gas transmission is further provided on the compressor. A first-stage exhaust port is provided on the outer side surface of the first-stage volute. A second-stage suction port is provided at one end of the second-stage volute away from the second-stage motor cylinder. Both ends of the medium-pressure connecting pipe are respectively installed in the first-stage exhaust port and the second-stage suction port.

[0016] Preferably, a first-stage suction pipe is externally connected to one end of the first-stage volute away from the first-stage motor cylinder. A second-stage exhaust pipe is externally connected to the outer side surface of the second stage.

[0017] In summary, the advantages of the present utility model are as follows:

[0018] By using a flange to combine two different and independently operating motors, the high and low pressure stages of this compressor can be independently adjusted, solving the adjustment of the compressor to achieve the optimal inter-stage pressure under a large pressure ratio, realizing the optimal isentropic compression efficiency, and thus achieving an energy-saving effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 For Embodiment 1: Schematic cross-sectional structure diagram of a compressor with double motors and two-stage compression;

[0020] Figure 2 For Embodiment 2: Schematic cross-sectional structure diagram of a compressor with double motors and three-stage compression (two first-stage impellers in series);

[0021] Figure 3 For Embodiment 3: Schematic cross-sectional structure diagram of a compressor with double motors and three-stage compression (two second-stage impellers in series);

[0022] Figure 4 For Embodiment 4: Schematic cross-sectional structure diagram of a compressor with double motors and four-stage compression;

[0023] Reference numerals: 1, flange; 2, first-stage motor; 3, second-stage motor; 4, medium-pressure connecting pipe; 21, first-stage motor cylinder; 22, first-stage rotor; 23, first-stage stator; 24, first-stage magnetic bearing; 25, first-stage thrust bearing; 26, first-stage volute; 27, first-stage impeller; 31, second-stage motor cylinder; 32, second-stage rotor; 33, second-stage stator; 34, second-stage magnetic bearing; 35, second-stage thrust bearing; 36, second-stage volute; 37, second-stage impeller; 41, first-stage exhaust port; 42, second-stage suction port; 43, first-stage suction pipe; 44, second-stage exhaust pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0025] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0026] At the same time, it should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0027] The following will make a detailed description of the specific implementation manners of the present utility model in conjunction with the drawings.

[0028] As Figures 1 to 4 shown, a multi-stage compression magnetic levitation centrifugal compressor with independent speeds, the compressor includes a flange 1 and an independently operating first-stage motor 2 and second-stage motor 3. Both sides of the flange 1 are respectively fixedly connected to one end of the first-stage motor 2 (a housing flange for connecting the flange 1 is provided at this end of the first-stage motor 2) and one end of the second-stage motor 3 (a housing flange for connecting the flange 1 is provided at this end of the second-stage motor 3), and the first-stage motor 2 and the second-stage motor 3 are basically arranged to extend along the direction of the first straight line L1.

[0029] By providing two independently operating motors, different speeds can be provided for the compressor, thereby further improving the pressure ratio.

[0030] Specifically as Figure 1 shown:

[0031] The first-stage motor 2 includes a first-stage motor cylinder 21 arranged to extend along the direction of the first straight line L1 and a first-stage rotor 22, a first-stage stator 23, a first-stage magnetic bearing 24, and a first-stage thrust bearing 25 provided in the first-stage motor cylinder 21; wherein, the first-stage rotor 22 is axially arranged in the first-stage motor cylinder 21 along the direction of the first straight line L1, and the first-stage stator 23 is arranged in the middle of the first-stage rotor 22. There are two sets of the above-mentioned first-stage magnetic bearings 24, which are respectively mounted on both ends of the first-stage rotor 22, and the first-stage thrust bearing 25 is sleeved on the first-stage rotor 22 and is located between the flange 1 and the first-stage magnetic bearing 24 close to the flange 1, and is used to support and stabilize the first-stage rotor 22.

[0032] The secondary motor 3 includes a secondary motor cylinder 31 extending along the first straight line L1, and a secondary rotor 32, a secondary stator 33, a secondary magnetic bearing 34, and a secondary thrust bearing 35 disposed within the secondary motor cylinder 31. Among them, the secondary rotor 32 is axially disposed within the secondary motor cylinder 31 along the first straight line L1, and the secondary stator 33 is installed in the middle of the secondary rotor 32. There are two sets of the above-mentioned secondary magnetic bearings 34, which are respectively mounted on both ends of the secondary rotor 32. The secondary thrust bearing 35 is sleeved on the secondary rotor 32 and is located between the flange 1 and the secondary magnetic bearing 34 close to the flange 1, and is used to support and stabilize the secondary rotor 32.

[0033] As Figure 1 shown, a primary volute 26 is provided at one end of the primary motor 2 away from the flange 1, and a primary impeller 27 is installed within the primary volute 26. The main surface of the primary impeller 27 is fixedly connected to the end of the primary rotor 22.

[0034] A secondary volute 36 is provided at one end of the secondary motor 3 away from the flange 1, and a secondary impeller 37 is installed within the secondary volute 36. The main surface of the secondary impeller 37 is fixedly connected to the end of the secondary rotor 32. The blades of the above-mentioned primary impeller 27 and secondary impeller 37 face in opposite directions.

[0035] As Figure 1 shown, a primary exhaust port 41 is provided on the outer side surface of the primary volute 26, a secondary suction port 42 is provided at one end of the secondary volute 36 away from the secondary motor cylinder 31, and a medium-pressure connecting pipe 4 for gas transmission is further provided on this compressor. Both ends of the medium-pressure connecting pipe 4 are respectively installed within the primary exhaust port 41 and the secondary suction port 42, and a gas supplement port is provided on the medium-pressure connecting pipe 4.

[0036] Furthermore, a primary suction pipe 43 is externally connected to one end of the primary volute 26 away from the primary motor cylinder 21, and a secondary exhaust pipe 44 is externally connected to the outer side surface of the secondary.

[0037] As Figures 1 to 4 shown:

[0038] Since the two motors in this compressor operate independently, the primary motor 2 and the primary impeller 27, and the secondary motor 3 and the secondary impeller 37 can be regarded as two single-motor single-side impeller compressors. The number of primary impellers 27 in this compressor can be set to one or more, and the number of secondary impellers 37 can also be set to one or more. This compressor can customize the number of primary impellers 27 and secondary impellers 37 according to actual situations.

[0039] When the number of the primary impellers 27 is greater than or equal to two, they are extended in series along the second straight line L1 to form a first impeller unit, which is installed in the primary volute 26 .

[0040] When the number of the secondary impellers 37 is greater than or equal to two, they are extended in series along the first straight line L2 to form a second impeller unit, which is installed in the secondary volute 36 .

[0041] Through the above-mentioned compressor structure, it is possible to solve the problems of large pressure ratio, multi-stage optimal speed regulation and optimal intermediate air supply pressure.

[0042] The above is a description of the embodiments of the utility model. Through the above description of the disclosed embodiments, professionals and technicians in the field can implement or use the utility model. Various modifications to these embodiments will be obvious to professionals and technicians in the field. The general principles defined in this article can be implemented in other embodiments without departing from the spirit or scope of the utility model. Therefore, the utility model will not be limited to these embodiments shown in this article, but will conform to the widest range consistent with the principles and novelties disclosed in this article.

Claims

1. A multi-stage compression magnetic suspension centrifugal compressor with independent speed, characterized in that: The compressor comprises a flange (1) and an independently operated primary motor (2) and a secondary motor (3), wherein two sides of the flange (1) are respectively fixedly connected to one end of the primary motor (2) and one end of the secondary motor (3), and the primary motor (2) and the secondary motor (3) are basically extended along the direction of a first straight line L1.

2. The multi-stage compression magnetic suspension centrifugal compressor with independent speed according to claim 1, characterized in that: A primary volute (26) is provided on the end of the primary motor (2) away from the flange (1), a primary impeller (27) is arranged in the primary volute (26), one end of the primary impeller (27) is connected to a primary rotor (22) extending into the primary volute (26); a secondary volute (36) is provided on the end of the secondary motor (3) away from the flange (1), a secondary impeller (37) is arranged in the secondary volute (36), one end of the secondary impeller (37) is connected to a secondary rotor (32) extending into the secondary volute (36); the blades of the primary impeller (27) and the secondary impeller (37) are oriented in opposite directions.

3. The multi-stage compression magnetic suspension centrifugal compressor with independent speed according to claim 2, characterized in that: At least two of the first-stage impellers (27) are provided, and are extended in series along the direction of the second straight line L2 to form a first impeller unit, and the first impeller unit is installed in the first-stage volute (26).

4. The multi-stage compression magnetic suspension centrifugal compressor with independent speed according to claim 2, characterized in that: At least two secondary impellers (37) are provided, and are extended in series along the direction of the first straight line L1 to form a second impeller unit. The second impeller unit is installed in the secondary volute (36).

5. The multi-stage compression magnetic suspension centrifugal compressor with independent speed according to claim 1, characterized in that: The primary motor (2) comprises a primary motor cylinder (21), a primary rotor (22) arranged in the primary motor cylinder (21), a primary stator (23) and a primary magnetic bearing (24), wherein the primary rotor (22) is axially arranged in the primary motor cylinder (21) along a first straight line L1 direction, the primary stator (23) is arranged in the middle of the primary rotor (22), and the primary magnetic bearing (24) is provided with two groups and is respectively mounted on both ends of the primary rotor (22).

6. The multi-stage compression magnetic suspension centrifugal compressor with independent speed according to claim 5, characterized in that: The primary motor (2) further comprises a primary thrust bearing (25) for stabilizing the primary rotor (22); the primary thrust bearing (25) is sleeved on the primary rotor (22) and is located between the flange (1) and the primary magnetic bearing (24).

7. The multi-stage compression magnetic suspension centrifugal compressor with independent speed according to claim 1, characterized in that: The secondary motor (3) comprises a secondary motor barrel (31), a secondary rotor (32), a secondary stator (33) and a secondary magnetic bearing (34) arranged in the secondary motor barrel (31); the secondary rotor (32) is axially arranged in the secondary motor barrel (31) along the direction of a first straight line L1; the secondary stator (33) is arranged in the middle of the secondary rotor (32); and the secondary magnetic bearing (34) is provided with two groups and is respectively mounted on both ends of the secondary rotor (32).

8. The multi-stage compression magnetic suspension centrifugal compressor with independent speed according to claim 7, characterized in that: The secondary motor (3) further comprises a secondary thrust bearing (35) for stabilizing the secondary rotor (32); the secondary thrust bearing (35) is sleeved on the secondary rotor (32) and is located between the flange (1) and the secondary magnetic bearing (34).

9. The multi-stage compression magnetic suspension centrifugal compressor with independent speed according to claim 2, characterized in that: The compressor is also provided with a medium-pressure connecting pipe (4) for gas transmission; a first-stage exhaust port (41) is provided on the outer side surface of the first-stage volute (26); a second-stage air intake port (42) is provided on the end of the second-stage volute (36) away from the second-stage motor cylinder (31); and two ends of the medium-pressure connecting pipe (4) are respectively arranged in the first-stage exhaust port (41) and the second-stage air intake port (42).

10. The multi-stage compression magnetic suspension centrifugal compressor with independent speed according to claim 9, characterized in that: A first-stage air intake pipe (43) is externally connected to one end of the first-stage volute (26) away from the first-stage motor cylinder (21); and a second-stage exhaust pipe (44) is externally connected to the outer side surface of the second stage.

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