Centrifugal compressor

Abstract

According to the centrifugal compressor, a motor cavity is defined by a shell, and a plurality of pressing wheels are arranged at the two ends of a rotor shaft respectively; in the height direction of the centrifugal compressor, the first medium inlet is located in the lower end of the shell, the second medium inlet is located in the upper end of the shell, the medium outlet is located between the first medium inlet and the second medium inlet, and the first medium inlet, the second medium inlet and the medium outlet all communicate with the motor cavity. Therefore, the multiple pressing wheels are arranged at the two ends of the rotor shaft correspondingly, staged compression of gas can be achieved, the centrifugal compressor can achieve the higher pressure ratio, and the operation efficiency of the centrifugal compressor is improved; according to the centrifugal compressor, the first medium inlet is located in the lower end of the shell, the second medium inlet is located in the upper end of the shell, and the medium outlet is located between the first medium inlet and the second medium inlet, so that the flowing-in and flowing-out positions and the flowing speed of media are reasonable, the cooling effect of the centrifugal compressor can be remarkably improved, and the working performance of the centrifugal compressor is improved.

Description

Technical Field

[0001] The present invention relates to the field of compressors, and more particularly to a centrifugal compressor. Background Art

[0002] In the related art, the overall operating efficiency of a centrifugal compressor is not high, it is difficult to be reliably used in a low-temperature environment, and moreover, the cooling capacity of the centrifugal compressor is poor. The poor cooling capacity also limits the working performance of the centrifugal compressor, thereby affecting the overall operating efficiency of the centrifugal compressor. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, an object of the present invention is to provide a centrifugal compressor that can achieve staged compression of gas, improve the operating efficiency of the centrifugal compressor, and has good cooling effect, which is beneficial to improving the working performance of the centrifugal compressor.

[0004] The centrifugal compressor according to the present invention includes: a motor, the motor includes a rotor shaft and a housing, the housing defines a motor cavity, and the rotor shaft passes through the motor cavity; a plurality of compression wheels, the plurality of compression wheels are respectively arranged at both ends of the rotor shaft; the housing has a first medium inlet, a second medium inlet, and a medium outlet. Along the height direction of the centrifugal compressor, the first medium inlet is located at the lower end of the housing, the second medium inlet is located at the upper end of the housing, and the medium outlet is located between the first medium inlet and the second medium inlet. The first medium inlet, the second medium inlet, and the medium outlet are all communicated with the motor cavity, and the medium can flow into the motor cavity through the first medium inlet and the second medium inlet, and the medium can flow out of the motor cavity through the medium outlet.

[0005] For the centrifugal compressor according to the present invention, by arranging a plurality of compression wheels at both ends of the rotor shaft, staged compression of gas can be achieved, enabling the centrifugal compressor to achieve a higher pressure ratio and improve the operating efficiency of the centrifugal compressor. Moreover, by making the first medium inlet located at the lower end of the housing, the second medium inlet located at the upper end of the housing, and the medium outlet located between the first medium inlet and the second medium inlet, the positions and flow rates of the medium flowing in and out can be made reasonable, and the cooling effect of the centrifugal compressor can be significantly improved to improve the working performance of the centrifugal compressor.

[0006] In some examples of the present invention, there are a plurality of the medium outlets, and at least one of the medium outlets is located at the lower end of the rotor shaft.

[0007] In some examples of the present invention, along the width direction of the centrifugal compressor and from the inner side of the rotor shaft to the outer side of the rotor shaft, the medium outlet located at the lower end of the rotor shaft gradually tilts downward.

[0008] In some examples of the present invention, the number of the first medium inlets, the number of the second medium inlets, and the number of the medium outlets are all at least one; and the first medium inlet is configured as a liquid medium inlet, the second medium inlet is configured as a gaseous medium inlet, and the medium is a phase change medium.

[0009] In some examples of the present invention, the motor further includes: an air radial bearing, wherein the air radial bearing is sleeved on the rotor shaft and located between the rotor shaft and the housing.

[0010] In some examples of the present invention, the motor further includes: a back plate, a plurality of air thrust bearings and a thrust plate, wherein the back plate is arranged and connected to the shell along the axial direction of the rotor shaft, the thrust plate is arranged between the back plate and the shell, the plurality of air thrust bearings are arranged on both sides of the thrust plate, and the plurality of air thrust bearings are all arranged between the back plate and the shell, and the air thrust bearings are used to support the rotor shaft.

[0011] In some examples of the present invention, the housing includes an outer shell, a cooling channel is formed in the outer shell, and a heat dissipation structure is formed on an inner surface of the cooling channel.

[0012] In some examples of the present invention, the outer shell includes: a first outer shell and a second outer shell, the first outer shell is sleeved on the outside of the second outer shell and is detachably connected to the second outer shell, a first groove is formed on the surface of the first outer shell facing the second outer shell, and a second groove is formed on the surface of the second outer shell facing the first outer shell, and the first groove and the second groove are opposite to each other to define the cooling channel.

[0013] In some examples of the present invention, the plurality of pressure wheels include: a primary pressure wheel, a secondary pressure wheel and a tertiary pressure wheel, the primary pressure wheel is fixedly arranged at the first end of the rotor shaft, the primary pressure wheel has a primary pressure wheel nose and a primary pressure wheel back, the primary pressure wheel nose is located at a side of the primary pressure wheel back away from the motor;

[0014] The secondary pressure wheel is fixedly arranged at the second end of the rotor shaft, the secondary pressure wheel comprises a secondary pressure wheel nose and a secondary pressure wheel back, the secondary pressure wheel back is located at a side of the secondary pressure wheel nose away from the motor, and the secondary pressure wheel is used to compress the gas compressed by the primary pressure wheel;

[0015] The third-stage pressure wheel is fixedly arranged at the second end of the rotor shaft and is located on the side of the second-stage pressure wheel away from the motor. The third-stage pressure wheel has a third-stage pressure wheel nose and a third-stage pressure wheel back. The third-stage pressure wheel nose is located on the side of the third-stage pressure wheel back away from the motor. The third-stage pressure wheel is used to compress the gas compressed by the second-stage pressure wheel.

[0016] In some examples of the present invention, the first-stage pressure wheel and the second-stage pressure wheel are configured as closed impellers, and the third-stage pressure wheel is configured as an open impeller.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 is a cross-sectional view of a centrifugal compressor according to an embodiment of the present invention;

[0020] Figure 2 is a cross-sectional view of the centrifugal compressor from another angle according to an embodiment of the present invention.

[0021] Reference Signs:

[0022] Centrifugal compressor 100;

[0023] First medium inlet 1; Second medium inlet 2; Medium outlet 3;

[0024] Motor 10; Rotor shaft 11; Motor cavity 12; Cooling flow channel 121;

[0025] Air radial bearing 13; First air radial bearing 131; Second air radial bearing 132;

[0026] Housing 16; Outer housing 161; First outer housing 1611; Second outer housing 1612; Mounting seat 162; End housing 163;

[0027] Stator 17; Pressure wheel 20;

[0028] First-stage pressure wheel 21; First-stage pressure wheel nose 211; First-stage pressure wheel back 212;

[0029] Second-stage pressure wheel 22; Second-stage pressure wheel nose 221; Second-stage pressure wheel back 222;

[0030] Third-stage pressure wheel 23; Third-stage pressure wheel nose 231; Third-stage pressure wheel back 232;

[0031] Air thrust bearing 30; thrust disk 31; back plate 40. Detailed implementation mode

[0032] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0033] Refer to the following Figure 1 - Figure 2 to describe the centrifugal compressor 100 of a vehicle according to an embodiment of the present invention.

[0034] As Figure 1 - Figure 2 shown, the centrifugal compressor 100 according to an embodiment of the present invention includes: a motor 10 and a plurality of compression wheels 20.

[0035] The motor 10 includes a rotor shaft 11 and a housing 16. The housing 16 defines a motor cavity 12, and the rotor shaft 11 passes through the motor cavity 12; the plurality of compression wheels 20 are respectively arranged at both ends of the rotor shaft 11; the housing 16 has a first medium inlet 1, a second medium inlet 2, and a medium outlet 3. Along the height direction of the centrifugal compressor 100 (i.e., Figure 1 the Z direction shown), the first medium inlet 1 is located at the lower end of the housing 16, the second medium inlet 2 is located at the upper end of the housing 16, and the medium outlet 3 is located between the first medium inlet 1 and the second medium inlet 2. The first medium inlet 1, the second medium inlet 2, and the medium outlet 3 are all communicated with the motor cavity 12. The medium can flow into the motor cavity 12 through the first medium inlet 1 and the second medium inlet 2, and the medium can flow out of the motor cavity 12 through the medium outlet 3.

[0036] Wherein, the rotor shaft 11 extends along the length direction of the centrifugal compressor 100 (i.e., Figure 1 the X direction shown), the length direction of the centrifugal compressor 100 (i.e., Figure 1 the X direction shown) is parallel to the axis direction of the rotor shaft 11. The material of the rotor shaft 11 can be, but is not limited to, magnetic steel, etc. The housing 16 can define the motor cavity 12, the rotor shaft 11 can pass through the motor cavity 12, and moreover, the rotor shaft 11 can rotate relative to the housing 16.

[0037] The number of the pressing wheels 20 can be multiple, and the number of the pressing wheels 20 can be, but is not limited to, two, three, four, etc. The types of the pressing wheels 20 can be, but are not limited to, impellers, etc. As some embodiments of the present application, the number of the pressing wheels 20 is three, including a primary pressing wheel 21, a secondary pressing wheel 22, and a tertiary pressing wheel 23. The primary pressing wheel 21 and the secondary pressing wheel 22 are open impellers, and the tertiary pressing wheel 23 is a closed impeller. The rotor shaft 11 is connected to the primary pressing wheel 21, the secondary pressing wheel 22, and the tertiary pressing wheel 23. Specifically, the primary pressing wheel 21, the secondary pressing wheel 22, and the tertiary pressing wheel 23 are all sleeved on the rotor shaft 11. The primary pressing wheel 21 is fixedly arranged at the first end of the rotor shaft 11 by means of bolt connection with the rotor shaft 11. The secondary pressing wheel 22 is fixedly arranged at the second end of the rotor shaft 11 by means of bolt connection with the rotor shaft 11. The tertiary pressing wheel 23 is fixedly arranged at the second end of the rotor shaft 11 by means of bolt connection with the rotor shaft 11. The secondary pressing wheel 22 is located between the tertiary pressing wheel 23 and the primary pressing wheel 21. The rotor shaft 11 can drive the primary pressing wheel 21, the secondary pressing wheel 22, and the tertiary pressing wheel 23 to rotate together. Moreover, when the primary pressing wheel 21 rotates, the primary pressing wheel 21 can compress the gas located inside the primary pressing wheel 21. When the secondary pressing wheel 22 rotates, the secondary pressing wheel 22 can compress the gas located inside the secondary pressing wheel 22. When the tertiary pressing wheel 23 rotates, the tertiary pressing wheel 23 can compress the gas located inside the tertiary pressing wheel 23. By performing staged compression on the gas, the pressure ratio of the gas can be further increased, enabling the centrifugal compressor 100 to achieve a higher pressure ratio and significantly improving the operating efficiency of the centrifugal compressor 100.

[0038] The number of the first medium inlets 1, the number of the second medium inlets 2, and the number of the medium outlets 3 are all at least one. Specifically, the number of the first medium inlets 1 can be, but is not limited to, one, two, three, etc. The number of the second medium inlets 2 can be, but is not limited to, one, two, three, etc. The number of the medium outlets 3 can be, but is not limited to, one, two, three, etc. The first medium inlets 1, the second medium inlets 2, and the medium outlets 3 are all communicated with the motor cavity 12 defined by the housing 16. The medium can flow into the motor cavity 12 through the first medium inlets 1 and the second medium inlets 2, and the medium can flow out of the motor cavity 12 through the medium outlets 3. It should be explained that the medium can be constructed as a phase change medium that can undergo a phase change under specific temperature and pressure conditions. The phase change medium has strong heat exchange ability and can effectively cool the centrifugal compressor 100. The medium can be, but is not limited to, paraffin, fatty acids, etc. As some embodiments of the present application, the medium is paraffin.

[0039] As some embodiments of the present application, as Figure 2 shown, along the height direction of the centrifugal compressor 100 (i.e., Figure 1In the Z direction shown, a first medium inlet 1 is located at the lower end of the housing 16, two second medium inlets 2 are located at the upper end of the housing 16 (for example, at the terminal board of the housing 16), and two medium outlets 3 are located between the first medium inlet 1 and the second medium inlet 2 (the two medium outlets 3 have different heights). The liquid-phase medium can be introduced into the motor cavity 12 from the first medium inlet 1, and the gas-phase medium can be introduced into the motor cavity 12 from the economizer (or other components) through the second medium inlet 2. The liquid-phase medium takes away the heat generated during the operation of the motor 10 through phase change (the medium absorbs heat when changing from liquid phase to gas phase), and the gas-phase medium can also reduce the temperature of the motor 10. Finally, the medium flows out of the motor cavity 12 through the medium outlet 3 to achieve the technical effect of cooling the motor 10.

[0040] It should be noted that in some extremely cold cases, the external temperature is relatively low, which easily leads to low working efficiency and operating efficiency when the centrifugal compressor 100 is used as a heat pump. However, for the centrifugal compressor 100 of the present application, through staged compression, a higher pressure ratio can be achieved, the operating efficiency of the centrifugal compressor 100 can be improved, and the working performance of the centrifugal compressor 100 can be enhanced. Moreover, by making the first medium inlet 1 located at the lower end of the housing 16, the second medium inlet 2 located at the upper end of the housing 16, and the medium outlet 3 located between the first medium inlet 1 and the second medium inlet 2, the installation positions of the first medium inlet 1, the second medium inlet 2, and the medium outlet 3 can be made reasonable, the inflow and outflow positions and flow rates of the medium can be made reasonable, the cooling effect of the centrifugal compressor 100 can be significantly improved, and the centrifugal compressor 100 can maintain an appropriate temperature even under long-term high-power operating conditions, which is beneficial to improving the working performance of the centrifugal compressor.

[0041] Therefore, by arranging a plurality of pressure wheels 20 at both ends of the rotor shaft 11 respectively, staged compression of the gas can be achieved, enabling the centrifugal compressor 100 to achieve a higher pressure ratio and improve the operating efficiency of the centrifugal compressor 100. Moreover, by making the first medium inlet 1 located at the lower end of the housing 16, the second medium inlet 2 located at the upper end of the housing 16, and the medium outlet 3 located between the first medium inlet 1 and the second medium inlet 2, the inflow and outflow positions and flow rates of the medium can be made reasonable, and the cooling effect of the centrifugal compressor 100 can be significantly improved to improve the working performance of the centrifugal compressor 100.

[0042] In some embodiments of the present invention, there are a plurality of medium outlets 3, and at least one medium outlet 3 is located at the lower end of the rotor shaft 11.

[0043] Among them, the number of the medium outlets 3 can be, but is not limited to, two, three, four, etc. As some embodiments of the present application, such as Figure 2As shown, the number of the medium outlets 3 is two, and one medium outlet 3 is located at the lower end of the rotor shaft 11. In some embodiments of the present application, the number of the medium outlets 3 is two, and both of the two medium outlets 3 are located at the lower end of the rotor shaft 11.

[0044] By making the medium outlets 3 multiple, the exchange rate of the medium in the motor cavity 12 can be increased, and the cooling effect of the centrifugal compressor 100 can be improved. Moreover, by making at least one medium outlet 3 located at the lower end of the rotor shaft 11, the risk that the highest liquid level of the liquid medium in the motor cavity 12 exceeds the lower end of the rotor shaft 11 can be reduced (because when it is about to exceed the lower end of the rotor shaft 11, the liquid medium will flow out from the medium outlet 3), which is beneficial to improving the operation stability of the centrifugal compressor 100.

[0045] In some embodiments of the present invention, as Figure 2 shown, along the width direction of the centrifugal compressor 100 (i.e., Figure 2 the Y direction shown), and from the inner side to the outer side of the rotor shaft 11, the medium outlets 3 located at the lower end of the rotor shaft 11 are gradually inclined downward.

[0046] In some embodiments of the present application, the number of the medium outlets 3 is two, and one medium outlet 3 is located at the lower end of the rotor shaft 11. Along the width direction of the centrifugal compressor 100 (i.e., Figure 2 the Y direction shown), and from the inner side to the outer side of the rotor shaft 11, the medium outlets 3 located at the lower end of the rotor shaft 11 are gradually inclined downward. Specifically, the axes of the medium outlets 3 located at the lower end of the rotor shaft 11 are gradually inclined downward.

[0047] By making the medium outlets 3 located at the lower end of the rotor shaft 11 gradually inclined downward, the medium can easily flow out from the medium outlets 3 located at the lower end of the rotor shaft 11, the risk that the highest liquid level of the liquid medium in the motor cavity 12 exceeds the lower end of the rotor shaft 11 can be effectively reduced, and the risk that the working of the rotor shaft 11 is affected by the too high liquid level of the liquid medium can be reduced, which is beneficial to improving the operation stability of the centrifugal compressor 100.

[0048] In some embodiments of the present invention, as Figure 2 shown, the number of the first medium inlets 1, the number of the second medium inlets 2, and the number of the medium outlets 3 are all at least one; and the first medium inlet 1 is configured as a liquid medium inlet, the second medium inlet 2 is configured as a gaseous medium inlet, and the medium is a phase change medium.

[0049] The number of the first medium inlets 1, the number of the second medium inlets 2, and the number of the medium outlets 3 are all at least one. The number of the first medium inlets 1 can be, but is not limited to, one, two, three, etc. The number of the second medium inlets 2 can be, but is not limited to, one, two, three, etc. The number of the medium outlets 3 can be, but is not limited to, one, two, three, etc. The first medium inlets 1, the second medium inlets 2, and the medium outlets 3 are all communicated with the motor cavity 12 defined by the housing 16. The medium can flow into the motor cavity 12 through the first medium inlets 1 and the second medium inlets 2, and the medium can flow out of the motor cavity 12 through the medium outlets 3. It should be noted that the medium is a phase change medium that can undergo a phase change under specific temperature and pressure conditions. For example, the medium can be, but is not limited to, paraffin, fatty acid, etc. In some embodiments of the present application, the medium is paraffin.

[0050] In some embodiments of the present application, as Figure 1 shown, along the height direction of the centrifugal compressor 100 (i.e., Figure 1 the Z direction shown), one first medium inlet 1 is located at the lower end of the housing 16, two second medium inlets 2 are located at the upper end of the housing 16 (for example, at the terminal board of the housing 16), and two medium outlets 3 are located between the first medium inlet 1 and the second medium inlet 2. The liquid-phase medium can be introduced into the motor cavity 12 through the first medium inlet 1, and the gas-phase medium can be introduced into the motor cavity 12 from the economizer (or other components) through the second medium inlet 2. The liquid-phase medium takes away the heat generated during the operation of the motor 10 through phase change (the medium absorbs heat when changing from the liquid phase to the gas phase), and the gas-phase medium can also reduce the temperature of the motor 10. Then the medium (generally the gas-phase medium) flows out of the motor cavity 12 through the medium outlet 3 to achieve the technical effect of cooling the motor 10.

[0051] Such a setting can quickly take away the heat of the motor 10, significantly improve the cooling effect of the centrifugal compressor 100, reduce the risk of overheating of the motor 10, and is beneficial to extending the service life of the centrifugal compressor 100.

[0052] In some embodiments of the present invention, as Figure 1 shown, the motor 10 further includes: an air radial bearing 13, and the air radial bearing 13 is sleeved on the rotor shaft 11 and located between the rotor shaft 11 and the housing 16.

[0053] In some embodiments of the present application, the housing 16 includes an outer housing 161, a mounting seat 162, and an end housing 163. The outer housing 161 includes a first outer housing 1611 and a second outer housing 1612. The air radial bearing 13 includes a first air radial bearing 131 and a second air radial bearing 132. Among them, the first outer housing 1611 is sleeved on the outside of the second outer housing 1612. Along the axial direction of the rotor shaft 11 (i.e., Figure 1In the X direction shown, the end housing 163 and the mounting base 162 are respectively disposed at both ends of the first outer housing 1611. Among them, the end housing 163 is integrally formed with the second outer housing 1612. The first air radial bearing 131 is sleeved on the rotor shaft 11 and is located between the rotor shaft 11 and the mounting base 162. The second air radial bearing 132 is sleeved on the rotor shaft 11 and is located between the rotor shaft 11 and the end housing 163.

[0054] By sleeving the air radial bearing 13 on the rotor shaft 11 and locating it between the rotor shaft 11 and the housing 16, the rotor shaft 11 can rotate relative to the housing 16. Moreover, the air radial bearing 13 has characteristics such as low energy consumption, long service life, and low noise. Such an arrangement can significantly improve the service life and operating efficiency of the centrifugal compressor 100, which is beneficial to improving the reliability of use of the centrifugal compressor 100. Additionally, the air radial bearing 13 requires an oil-free environment, and by applying a phase change medium for cooling, a reliable use environment can be provided for the air radial bearing 13.

[0055] In some embodiments of the present invention, as Figure 1 shown, the motor 10 further includes: a back plate 40, a plurality of air thrust bearings 30, and a thrust plate 31. Along the axial direction of the rotor shaft 11 (i.e., Figure 1 the X direction shown), the back plate 40 and the housing 16 are arranged and connected. The thrust plate 31 is disposed between the back plate 40 and the housing 16. The plurality of air thrust bearings 30 are respectively disposed on both sides of the thrust plate 31, and the plurality of air thrust bearings 30 are all disposed between the back plate 40 and the housing 16. The air thrust bearings 30 are used to support the rotor shaft 11.

[0056] Among them, the number of the air thrust bearings 30 can be, but is not limited to, two, three, four, etc. In this application, the case where the number of the air thrust bearings 30 is two is taken as an example for description. As some embodiments of this application, the housing 16 includes an outer housing 161, a mounting base 162, and an end housing 163. The outer housing 161 includes a first outer housing 1611 and a second outer housing 1612. Among them, the first outer housing 1611 is sleeved outside the second outer housing 1612. Along the axial direction of the rotor shaft 11 (i.e., Figure 1 the X direction shown), the end housing 163 and the mounting base 162 are respectively disposed at both ends of the first outer housing 1611. Among them, the end housing 163 is integrally formed with the second outer housing 1612. The back plate 40 and the end housing 163 are connected by means of bolts, and moreover, the back plate 40 and the end housing 163 are arranged. The back plate 40 is located at one end of the end housing 163 away from the mounting base 162. The thrust plate 31 is disposed between the back plate 40 and the end housing 163. The two air thrust bearings 30 are respectively disposed on both sides of the thrust plate 31, and the two air thrust bearings 30 are all disposed between the back plate 40 and the housing 16.

[0057] Specifically, one of the air thrust bearings 30 can abut against the end housing 163, and the other air thrust bearing 30 can abut against the back plate 40. The two air thrust bearings 30 are located in the gap between the end housing 163 and the back plate 40. The two air thrust bearings 30 can be fixedly arranged on the end housing 163 and the back plate 40 respectively through positioning pins. A thrust plate 31 can be arranged between the two air thrust bearings 30. The two air thrust bearings 30 are spaced apart. The air thrust bearings 30 can play a role in supporting the rotor shaft 11, and moreover, the air thrust bearings 30 can reduce the axial movement of the rotor shaft 11.

[0058] By arranging multiple air thrust bearings 30 on both sides of the thrust plate 31 and arranging the air thrust bearings 30 in the gap between the housing 16 and the back plate 40, it is beneficial to reduce the length dimension of the motor 10 along the axis direction of the rotor shaft 11 (i.e., Figure 1 the X direction shown), which is beneficial to reducing the space occupied by the motor 10. Moreover, such an arrangement can enable the air thrust bearings 30 to support the rotor shaft 11, can disperse the supporting force for supporting the rotor shaft 11, balance the axial force of the air pressure, and can play a role in supporting the rotor shaft 11 and reducing the axial movement of the rotor shaft 11, which is beneficial to improving the use reliability of the centrifugal compressor 100. In addition, the air thrust bearings 30 require an oil-free environment. By applying a phase change medium for cooling, a reliable use environment can be provided for the air thrust bearings 30.

[0059] In some embodiments of the present invention, as Figure 1 shown, the housing 16 includes an outer housing 161. A cooling flow channel 121 is formed inside the outer housing 161, and a heat dissipation structure is formed on the inner surface of the cooling flow channel 121.

[0060] Among them, the housing 16 includes an outer housing 161. As some embodiments of the present application, the housing 16 includes an outer housing 161, a mounting seat 162, and an end housing 163. The outer housing 161 includes a first outer housing 1611 and a second outer housing 1612. Among them, the first outer housing 1611 is sleeved outside the second outer housing 1612. Along the axis direction of the rotor shaft 11 (i.e., Figure 1In the X direction shown, the end housing 163 and the mounting base 162 are respectively arranged at both ends of the first outer housing 1611. Among them, the end housing 163 is integrally formed with the second outer housing 1612. A cooling flow channel 121 is formed inside the inner wall of the outer housing 161. The cooling flow channel 121 can surround the motor cavity 12. The cooling medium can flow inside the cooling flow channel 121. The cooling medium can be used to cool the motor 10, and the cooling medium can exchange heat with the inner surface of the cooling flow channel 121. A heat dissipation structure can be formed on the inner surface of the cooling flow channel 121. The heat dissipation structure can be configured as a serrated structure protruding from the inner surface of the cooling flow channel 121. By setting the heat dissipation structure, the contact area between the cooling medium and the cooling flow channel 121 can be increased, which is beneficial to improving the heat dissipation efficiency of the motor 10. And setting it like this can eliminate the need to set an inter-stage pipe, which can reduce the volume of the centrifugal compressor 100, thereby reducing the production cost of the centrifugal compressor 100.

[0061] As some embodiments of the present application, the cooling medium can be a phase change medium, or the cooling medium can be a cooling gas, or the cooling medium can be a cooling liquid.

[0062] As an example, as Figure 1 shown, the motor 10 further has a stator 17. The stator 17 is arranged on the inner side wall of the second outer housing 1612. The cooling medium in the cooling flow channel 121 can cool the stator 17 and part of the structure of the rotor shaft 11, so as to achieve the effect of further cooling the motor 10, which is beneficial to improving the heat dissipation performance of the centrifugal compressor 100.

[0063] In some embodiments of the present invention, as Figure 1 shown, the outer housing 161 includes: a first outer housing 1611 and a second outer housing 1612. The first outer housing 1611 is sleeved outside the second outer housing 1612 and is detachably connected to the second outer housing 1612. A first groove is formed on the surface of the first outer housing 1611 facing the second outer housing 1612, and a second groove is formed on the surface of the second outer housing 1612 facing the first outer housing 1611. The first groove and the second groove face each other to define the cooling flow channel 121.

[0064] Along the radial direction of the rotor shaft 11, the first outer shell 1611 can be sleeved on the outer side of the second outer shell 1612. The first outer shell 1611 can be connected to the second outer shell 1612 by means of clamping, bolting, etc. The first outer shell 1611 and the second outer shell 1612 are detachably connected. A first groove is formed on the surface of the first outer shell 1611 facing the second outer shell 1612, and the first groove is recessed toward the first outer shell 1611. A second groove is formed on the surface of the second outer shell 1612 facing the first outer shell 1611, and the second groove is recessed toward the second outer shell 1612. The first groove can be arranged opposite to the second groove, and the first groove can define a cooling channel 121 together with the second groove, and the cooling medium can flow in the cooling channel 121.

[0065] By making the first outer shell 1611 and the second outer shell 1612 detachably connected, the difficulty of production and installation of the shell 16 can be reduced, and the heat dissipation structure on the inner surface of the cooling channel 121 can be easily processed, which is conducive to reducing production costs.

[0066] In some embodiments of the present invention, Figure 1 As shown, the plurality of pressure rollers 20 include: a primary pressure roller 21, a secondary pressure roller 22 and a tertiary pressure roller 23. The primary pressure roller 21 is fixedly arranged at the first end of the rotor shaft 11. The primary pressure roller 21 has a primary pressure roller nose 211 and a primary pressure roller back 212. The primary pressure roller nose 211 is located at a side of the primary pressure roller back 212 away from the motor 10.

[0067] The secondary pressure roller 22 is fixedly arranged at the second end of the rotor shaft 11. The secondary pressure roller 22 has a secondary pressure roller nose 221 and a secondary pressure roller wheel back 222. The secondary pressure roller wheel back 222 is located at a side of the secondary pressure roller nose 221 away from the motor 10. The secondary pressure roller 22 is used to compress the gas compressed by the primary pressure roller 21.

[0068] The tertiary pressure wheel 23 is fixedly arranged at the second end of the rotor shaft 11 and is located on the side of the secondary pressure wheel 22 away from the motor 10. The tertiary pressure wheel 23 has a tertiary pressure wheel nose 231 and a tertiary pressure wheel back 232. The tertiary pressure wheel nose 231 is located on the side of the tertiary pressure wheel back 232 away from the motor 10. The tertiary pressure wheel 23 is used to compress the gas compressed by the secondary pressure wheel 22.

[0069] The pressure wheel 20 includes a primary pressure wheel 21 , a secondary pressure wheel 22 and a tertiary pressure wheel 23 , and the rotor shaft 11 is connected to the primary pressure wheel 21 , the secondary pressure wheel 22 and the tertiary pressure wheel 23 .

[0070] As some embodiments of the present application, the first-stage pressure wheel 21 is sleeved on the rotor shaft 11, and the first-stage pressure wheel 21 and the rotor shaft 11 are fixed to the first end of the rotor shaft 11 by bolt connection. The first-stage pressure wheel 21 has a first-stage pressure wheel nose 211 and a first-stage pressure wheel back 212. When the first-stage pressure wheel 21 is assembled with the rotor shaft 11, the first-stage pressure wheel nose 211 and the first-stage pressure wheel back 212 can be along the axial direction of the rotor shaft 11 (i.e. Figure 1 The first-stage pressing wheel nose 211 is located on the side of the first-stage pressing wheel back 212 away from the motor 10;

[0071] The secondary pressure wheel 22 is sleeved on the rotor shaft 11. The secondary pressure wheel 22 and the rotor shaft 11 are fixed to the second end of the rotor shaft 11 by bolt connection. The secondary pressure wheel 22 has a secondary pressure wheel nose 221 and a secondary pressure wheel back 222. When the secondary pressure wheel 22 and the rotor shaft 11 are assembled together, the secondary pressure wheel nose 221 and the secondary pressure wheel back 222 can be along the axial direction of the rotor shaft 11 (i.e. Figure 1 The secondary pressing wheel back 222 is located at the side of the secondary pressing wheel nose 221 away from the motor 10;

[0072] The three-stage pressure wheel 23 is sleeved on the rotor shaft 11. The three-stage pressure wheel 23 and the rotor shaft 11 are fixedly connected to the second end of the rotor shaft 11 by bolts. The three-stage pressure wheel 23 is located on the side of the two-stage pressure wheel 22 away from the motor 10. The three-stage pressure wheel 23 has a three-stage pressure wheel nose 231 and a three-stage pressure wheel back 232. When the three-stage pressure wheel 23 is assembled with the rotor shaft 11, the three-stage pressure wheel nose 231 and the three-stage pressure wheel back 232 can be along the axial direction of the rotor shaft 11 (i.e. Figure 1 The three-stage pressing wheel nose 231 is located on the side of the three-stage pressing wheel back 232 away from the motor 10;

[0073] The rotor shaft 11 can drive the first-stage pressure wheel 21, the second-stage pressure wheel 22, and the third-stage pressure wheel 23 to rotate together, and when the first-stage pressure wheel 21 rotates, the first-stage pressure wheel 21 can compress the gas located in the first-stage pressure wheel 21, when the second-stage pressure wheel 22 rotates, the second-stage pressure wheel 22 can compress the gas located in the second-stage pressure wheel 22, and when the third-stage pressure wheel 23 rotates, the third-stage pressure wheel 23 can compress the gas located in the third-stage pressure wheel 23, and the pressure value of the gas compressed by the second-stage pressure wheel 22 is higher than the pressure value of the gas compressed by the first-stage pressure wheel 21, and the pressure value of the gas compressed by the third-stage pressure wheel 23 is higher than the pressure value of the gas compressed by the second-stage pressure wheel 22. In this way, by compressing the gas in stages, the pressure ratio of the gas can be further increased, so that the centrifugal compressor 100 can achieve a higher pressure ratio, which significantly improves the operating efficiency of the centrifugal compressor 100.

[0074] By providing the first-stage pressing wheel 21, the second-stage pressing wheel 22, and the third-stage pressing wheel 23, the gas can first be compressed within the first-stage pressing wheel 21. The gas compressed by the first-stage pressing wheel 21 flows to the second-stage pressing wheel 22, and the second-stage pressing wheel 22 compresses the gas compressed by the first-stage pressing wheel 21, increasing the pressure of the gas. The gas compressed by the second-stage pressing wheel 22 flows to the third-stage pressing wheel 23, and the third-stage pressing wheel 23 compresses the gas compressed by the second-stage pressing wheel 22, further increasing the pressure ratio of the gas. This enables the staged compression of the gas, allowing the centrifugal compressor 100 to achieve a higher pressure ratio. Additionally, by arranging the back of the first-stage pressing wheel 21 facing the motor 10, the tip of the second-stage pressing wheel 22 facing the motor 10, and the back of the second-stage pressing wheel 22 and the back of the third-stage pressing wheel 23 being adjacently arranged, the rotor shaft 11 can be subjected to a smaller and stable axial force, enabling the rotor shaft 11 to rotate stably. This can also reduce the risk of gas leakage, decrease gas loss, and contribute to improving the stability of the centrifugal compressor 100 during operation and enhancing the working efficiency of the centrifugal compressor 100.

[0075] In some embodiments of the present invention, the first-stage pressing wheel 21 and the second-stage pressing wheel 22 are configured as closed impellers, and the third-stage pressing wheel 23 is configured as an open impeller. By configuring the first-stage pressing wheel 21 and the second-stage pressing wheel 22 as closed impellers and the third-stage pressing wheel 23 as an open impeller, the structural form of the pressing wheel 20 can be made reasonable, the rotor shaft 11 can be subjected to a smaller and stable axial force, enabling the rotor shaft 11 to rotate stably, which is beneficial to improving the stability of the centrifugal compressor 100. Moreover, the magnitude of the axial force can be within the bearing range of the air thrust bearing 30, reducing the risk of damage to the air thrust bearing 30 and contributing to extending the service life of the centrifugal compressor 100.

[0076] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0077] In the description of the present invention, "the first feature", "the second feature" may include one or more of such features.

[0078] In the description of the present invention, "a plurality of" means two or more.

[0079] In the description of the present invention, a first feature being "above" or "below" a second feature may include direct contact between the first and second features, or may include contact between the first and second features not being direct but through additional features therebetween.

[0080] In the description of the present invention, a first feature being "above", "over" or "on top of" a second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature.

[0081] In the description of this specification, descriptions with reference to terms such as "an embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0082] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A centrifugal compressor (100), characterized in that: include: A motor (10), the motor (10) comprising a rotor shaft (11) and a housing (16), the housing (16) defining a motor cavity (12), the rotor shaft (11) passing through the motor cavity (12); A plurality of pressure wheels (20), wherein the plurality of pressure wheels (20) are disposed at both ends of the rotor shaft (11); The shell (16) has a first medium inlet (1), a second medium inlet (2), and a medium outlet (3); along the height direction of the centrifugal compressor (100), the first medium inlet (1) is located at the lower end of the shell (16), the second medium inlet (2) is located at the upper end of the shell (16), and the medium outlet (3) is located between the first medium inlet (1) and the second medium inlet (2); the first medium inlet (1), the second medium inlet (2), and the medium outlet (3) are all connected to the motor cavity (12); the medium can flow into the motor cavity (12) through the first medium inlet (1) and the second medium inlet (2), and the medium can flow out of the motor cavity (12) through the medium outlet (3).

2. The centrifugal compressor (100) according to claim 1, characterized in that: There are multiple medium outlets (3), and at least one of the medium outlets (3) is located at the lower end of the rotor shaft (11).

3. The centrifugal compressor (100) according to claim 2, characterized in that: Along the width direction of the centrifugal compressor (100), and from the inner side of the rotor shaft (11) to the outer side of the rotor shaft (11), the medium outlet (3) located at the lower end of the rotor shaft (11) gradually tilts downward.

4. The centrifugal compressor (100) according to claim 1, characterized in that: The number of the first medium inlets (1), the number of the second medium inlets (2), and the number of the medium outlets (3) are all at least one; The first medium inlet (1) is configured as a liquid medium inlet, the second medium inlet (2) is configured as a gaseous medium inlet, and the medium is a phase change medium.

5. The centrifugal compressor (100) according to claim 1, characterized in that: The motor (10) further comprises an air radial bearing (13), wherein the air radial bearing (13) is sleeved on the rotor shaft (11) and is located between the rotor shaft (11) and the housing (16).

6. The centrifugal compressor (100) according to claim 1, characterized in that: The motor (10) further comprises: a back plate (40), a plurality of air thrust bearings (30) and a thrust plate (31); the back plate (40) is arranged and connected to the housing (16) along the axial direction of the rotor shaft (11); the thrust plate (31) is arranged between the back plate (40) and the housing (16); the plurality of air thrust bearings (30) are arranged on both sides of the thrust plate (31); and the plurality of air thrust bearings (30) are all arranged between the back plate (40) and the housing (16); and the air thrust bearings (30) are used to support the rotor shaft (11).

7. The centrifugal compressor (100) according to claim 1, characterized in that: The housing (16) comprises an outer shell (161), a cooling channel (121) is formed in the outer shell (161), and a heat dissipation structure is formed on the inner surface of the cooling channel (121).

8. The centrifugal compressor (100) according to claim 7, characterized in that: The outer shell (161) comprises: a first outer shell (1611) and a second outer shell (1612); the first outer shell (1611) is sleeved on the outside of the second outer shell (1612) and is detachably connected to the second outer shell (1612); a first groove is formed on the surface of the first outer shell (1611) facing the second outer shell (1612); a second groove is formed on the surface of the second outer shell (1612) facing the first outer shell (1611); the first groove and the second groove are opposite to each other to define the cooling channel (121).

9. The centrifugal compressor (100) according to any one of claims 1 to 8, characterized in that: The plurality of pressure wheels (20) include: a primary pressure wheel (21), a secondary pressure wheel (22) and a tertiary pressure wheel (23); the primary pressure wheel (21) is fixedly arranged at the first end of the rotor shaft (11); the primary pressure wheel (21) has a primary pressure wheel nose (211) and a primary pressure wheel back (212); the primary pressure wheel nose (211) is located on a side of the primary pressure wheel back (212) away from the motor (10); The secondary pressure wheel (22) is fixedly arranged at the second end of the rotor shaft (11), the secondary pressure wheel (22) comprises a secondary pressure wheel nose (221) and a secondary pressure wheel back (222), the secondary pressure wheel back (222) is located at a side of the secondary pressure wheel nose (221) away from the motor (10), and the secondary pressure wheel (22) is used to compress the gas compressed by the primary pressure wheel (21); The three-stage pressure wheel (23) is fixedly arranged at the second end of the rotor shaft (11) and is located on the side of the two-stage pressure wheel (22) facing away from the motor (10). The three-stage pressure wheel (23) has a three-stage pressure wheel nose (231) and a three-stage pressure wheel back (232). The three-stage pressure wheel nose (231) is located on the side of the three-stage pressure wheel back (232) facing away from the motor (10). The three-stage pressure wheel (23) is used to compress the gas compressed by the two-stage pressure wheel (22).

10. The centrifugal compressor (100) according to claim 9, characterized in that: The first-stage pressure wheel (21) and the second-stage pressure wheel (22) are configured as closed impellers, and the third-stage pressure wheel (23) is configured as an open impeller.

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