CN116317302A - A cooling structure for magnetic levitation centrifugal compressor motor - Google Patents

Abstract

The invention discloses a cooling structure for a magnetic levitation centrifugal compressor motor. The motor includes a rotor, a stator, and a casing that are sheathed in sequence. A heat dissipation gap is arranged between the rotor and the stator; the stator is fixed on the inner wall of the casing, and the All are provided with a heat dissipation area connected to the heat dissipation gap, and an air inlet and an air outlet connected to the heat dissipation area are fixedly provided on the casing; a water cooling flow channel is provided inside the casing, and a water inlet and a water outlet connected to the water cooling flow path are fixedly provided on the casing. The advantage of the present invention is that the two cooling modes of air cooling and water cooling are combined to dissipate heat together to improve the cooling efficiency of the magnetic levitation motor; the heat dissipation of the thrust bearing and the magnetic levitation bearing inside the motor can be completed, and the heat dissipation efficiency is strong.

Description

A cooling structure for magnetic levitation centrifugal compressor motor

technical field

The invention relates to the technical field of magnetic levitation motors, in particular to a cooling structure for a magnetic levitation centrifugal compressor motor.

Background technique

The magnetic levitation high-speed motor has become one of the hotspots in the field of international electrotechnical research. The main structure is that the blower impeller is directly installed on the extension end of the click shaft, and the rotor is vertically suspended on the active magnetic bearing to be directly driven by the high-speed motor. Using the magnetic levitation motor to drive the compressor-expander unit can effectively improve the system performance, and the cooling method of the magnetic levitation motor directly determines whether the motor can run stably and safely. Because the speed of the magnetic levitation motor is very high, it is necessary to take away the heat generated by the loss of the motor through cooling during operation, otherwise it will easily affect the normal operation of the motor.

In the prior art, one of air cooling or water cooling is usually used to realize the cooling of the magnetic levitation centrifugal compressor motor. For the selection of air-cooled and water-cooled modes, our company has conducted the following research.

In the Chinese patent literature, the patent number is CN202121792227.6, which was authorized and announced on February 18, 2022. It is a magnetic levitation motor shell and motor compatible with water-cooling and air-cooling systems. Blind holes for air cooling are set on the bearing seat and the second bearing seat. The purpose of this application is that the air holes in the blind holes can be opened for the introduction of cooling air in the application of air cooling. In the closed state, the water cooling of the motor is completed with the water cooling channel.

Although the prior art realizes the application of water cooling or air cooling, only one cooling method can be used in the actual cooling process, and the cooling efficiency is still relatively insufficient.

Contents of the invention

Based on the above-mentioned deficiencies in the prior art, the present application provides a cooling structure for a magnetic levitation centrifugal compressor motor. Air cooling and water cooling are combined to dissipate heat together to improve the cooling efficiency of the magnetic levitation motor.

In order to achieve the above object, the present invention proposes the following technical solutions.

A cooling structure for a magnetic levitation centrifugal compressor motor. The motor includes a rotor, a stator, and a casing that are sheathed in sequence, and a heat dissipation gap is provided between the rotor and the stator; In the heat dissipation area of the heat dissipation gap, an air inlet and an air outlet connected to the heat dissipation area are fixedly provided on the shell; a water cooling flow channel is provided inside the shell, and a water inlet and a water outlet connected to the water cooling flow channel are fixedly provided on the shell.

The cooling method combining water cooling and air cooling is adopted. The outer surface of the motor stator is water-cooled, and the motor rotor, wire package and inner ring of the motor stator are air-cooled. The two cooling methods act on the motor at the same time for cooling. Although the rotor, wire package And the inner ring of the stator is air-cooled, but the cooling airflow is further cooled after passing through the water-cooled motor casing at the air inlet, which has a higher cooling efficiency than ordinary air-cooled, thus ensuring an extremely low operating temperature when the motor is running.

Preferably, one end of the rotor is provided with a thrust bearing, and the spacer ring of the thrust bearing is provided with cooling holes communicating with the cooling area. When the magnetic levitation motor is working, the thrust plate is suspended at the center of the front and rear thrust bearings, with a gap of 0.5 mm on both sides. At this time, due to the high-speed rotation of the thrust disc, centrifugal force will be generated. There is a circle of cooling holes on the spacer ring of the thrust bearing. The heat generated by the thrust bearing will be taken out from the cooling holes to realize the cooling of the thrust bearing.

Preferably, the front end of the casing is provided with a front-end magnetic bearing seat, and a front-end radial magnetic bearing is provided in the front-end magnetic bearing seat, and a heat dissipation air port connected to the heat dissipation area is provided in the front end magnetic bearing seat, and the heat dissipation air port is connected to the heat dissipation area. There is a heat dissipation air outlet on the front magnetic bearing seat as an air channel, and the front radial magnetic bearing is guaranteed to be completely cooled through heat conduction; the design of the heat dissipation area and the heat dissipation air outlet increases the heat dissipation area, and the heat generated by the magnetic bearing is also passed through the water cooling belt. Walk.

Preferably, the casing is made of an aluminum stretched profile motor barrel, and the two ends of the casing are sealed by friction stir welding. The motor casing is made of aluminum stretched profile, which has high thermal conductivity; the two ends of the casing are sealed by friction stir welding, and a circulating axial water channel is formed inside to ensure the heat dissipation capacity of the casing.

Preferably, the position of the air inlet is directly opposite to the wire package on the stator. The air inlet is cooled and dissipated by an external heat dissipation fan, and blows air inwardly. The position of the air inlet is opposite to the wire package to ensure that the wire package is completely and fully cooled.

Preferably, the water-cooling flow channel includes several axial flow channels arranged parallel to the axis of the casing, and the axial flow channels are connected in series. Through the axial water flow, the flow channel and water cooling heat dissipation area are lengthened.

As a preference, there are twelve axial flow passages arranged in a circular array around the axis of the housing, the radial cross-sectional shape of the axial flow passage is arc-shaped, and the central angle of the radial cross-section of the axial flow passage is between 20 and Between 27 degrees. The axial flow channel corresponds to most of the area of the shell, and the heat dissipation area is large to ensure the cooling efficiency of the shell and the stator. The lateral dimension of the axial flow channel is large, which can effectively reduce the water resistance and improve the heat dissipation efficiency.

Preferably, the air inlet is arranged at the front end of the casing of the motor, the thrust bearing is arranged in the end of the magnetic bearing seat at the front end, and the cooling holes communicate with the cooling air outlets. When working, the cooling air will enter from the front end, flow out through the gap between the motor stator and the motor rotor, and finally flow out from the rear end wire wrap, which ensures the heat dissipation capacity of the thrust bearing and magnetic suspension bearing.

Preferably, the length of the air inlet in the axial direction of the motor ranges from 1/4 to 2/5 of the axial length of the stator. Ensure the cooling efficiency of the motor stator by the air intake at the air inlet.

The beneficial effects of the present invention are: air cooling and water cooling are combined to jointly dissipate heat to improve the cooling efficiency of the magnetic levitation motor; the heat dissipation of the thrust bearing and the magnetic levitation bearing inside the motor can be completed, and the heat dissipation efficiency is strong.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Fig. 2 is a structural schematic diagram of the casing in the present invention.

Fig. 3 is a cross-sectional view at A-A in Fig. 2 .

Fig. 4 is a cross-sectional view at B-B in Fig. 2 .

Fig. 5 is a cross-sectional view where one end of the axial flow channel is connected to adjacent axial flow channels.

Fig. 6 is a cross-sectional view at C-C in Fig. 5 .

In the figure: rotor 1 thrust disc 101 stator 2 wire package 201 heat dissipation gap 202 shell 3 air inlet 301 air outlet 302 water inlet 303 water outlet 304 thrust bearing 4 spacer 401 cooling hole 402 front end magnetic bearing seat 5 front radial magnetic bearing 501 Cooling air outlet 502 Front heat dissipation area 503 Rear end magnetic bearing seat 6 Rear heat dissipation area 601 Water cooling flow channel 7 Axial flow channel 701.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Example 1,

A cooling structure of a magnetic levitation centrifugal compressor motor, as shown in Figure 1 and Figure 2, the motor includes a rotor 1, a stator 2 and a casing 3 that are sequentially sleeved, the stator 2 is fixed on the inner wall of the casing 3, and the rotor 1 is connected to the An integral structure with integrated rotating shafts; a cooling gap 202 is provided between the rotor 1 and the stator 2 . Both ends of the stator 2 are provided with heat dissipation areas connected to the heat dissipation gap 202. The front end of the stator 2 is opposite to the thrust bearing 4 and the front end magnetic bearing seat 5 to form a front heat dissipation area 503; the rear end of the stator 2 and the rear end magnetic bearing seat 6 The gaps are opposite to form a rear heat dissipation area 601 . The housing 3 is fixed with an air inlet 301 and an air outlet 302 connected to the heat dissipation area; The air inlet 301 is arranged at the front end of the housing 3 of the motor. The position of the air inlet 301 in the axial direction of the motor is adjacent to the front cooling area 503. When the air inlet 301 takes in air, the air flows through the outer side of the wire package 201 on the stator 2 to the front magnetic bearing. Seat 5 and cooling gap 202. The length of the air inlet 301 in the axial direction of the motor is 8/25 of the axial length of the motor stator 2 . One end of the rotor 1 is provided with a thrust bearing 4 , and a spacer 401 between the two thrust bearings 4 is provided with a cooling hole 402 communicating with the cooling area. The front end of the housing 3 is provided with a front-end magnetic bearing seat 5, and the front-end magnetic bearing seat 5 is provided with a front-end radial magnetic bearing 501, and the front-end magnetic bearing seat 5 is provided with a cooling air outlet 502 connected to the heat dissipation area, and the thrust bearing 4 is arranged on the front-end magnetic bearing seat 5. In the end portion of the bearing housing 5 , the heat dissipation holes 402 communicate with the heat dissipation air outlets 502 . The heat dissipation air outlet 502 communicates with the heat dissipation area. A shoulder is set on the rotor 1 to form a thrust disc 101 that cooperates with the thrust bearing 4. When the motor is in operation, the thrust disc 101 is suspended to the middle position of the thrust bearing 4, and a gap is formed between the thrust disc 101 and the thrust bearings 4 on both sides, and the thrust disc 101 rotates. Centrifugal force is generated to throw out the internal air and heat together, and then enter the heat dissipation air outlet 502 through the heat dissipation hole 402 and be taken out together by the airflow flowing out to the heat dissipation air outlet 502 to realize the heat dissipation of the thrust bearing 4 . The housing 3 is provided with a water-cooling channel 7, as shown in Figure 3 to Figure 6, the water-cooling channel 7 includes several axial channels 701 arranged parallel to the axis of the housing 3, and the axial channels 701 are connected in series, specifically, the shaft One end of the flow channel 701 is connected to one end of the axial flow channel 701 on the adjacent side, and the other end of the axial flow channel 701 is connected to the other end of the axial flow channel 701 on the other side. The water channels communicated with 701 are arranged radially along the casing 3 . The axial flow channel 701 is provided with twelve circumferential arrays arranged around the axis of the housing 3. The radial cross-sectional shape of the axial flow channel 701 is arc-shaped, and the two ends of the radial cross-section of the axial flow channel 701 are linear. , the straight lines at both ends of the radial cross-section of the axial flow channel 701 form an included angle of 30 degrees, and there is a rounded transition between the two ends of the radial cross-section of the axial flow channel and the arc-shaped side of the axial flow channel 701 . The central angle of the radial cross section of the axial channel 701 is 24 degrees. The casing 3 is made of an aluminum stretch profile motor barrel, and both ends of the casing 3 are sealed by friction stir welding. The casing 3 is fixedly provided with a water inlet 303 and a water outlet 304 communicating with the water-cooling channel 7 . The water inlet 303 and the water outlet 304 communicate with the external cooling water circuit through pipes. The air inlet and the air outlet are connected to the external cooling air path. Since the air inlet 301 and the air outlet 302 are provided through the casing 3, the cooling airflow entering the air inlet 301 will be cooled by the water-cooled casing 3, so as to realize rapid overall heat dissipation. The two ends of the casing 3 of the motor are respectively provided with pump casings, and the two ends of the rotor 1 shaft of the motor are respectively provided with impellers in the corresponding pump casings.

This application adopts a combination of water cooling and air cooling. The outer surface of the motor stator 2 is water-cooled, and the motor rotor 1, wire package 201 and the inner ring of the motor stator 2 are air-cooled. The two cooling methods act on the motor at the same time for cooling , although the rotor 1, the wire package 201 and the inner ring of the stator 2 are air-cooled, the cooling air flow is further cooled after passing through the water-cooled motor casing 3 at the air inlet 301, which has a higher cooling efficiency than the general air-cooled, thus ensuring Extremely low operating temperature when the motor is running. In addition, this application not only has a combination of water cooling and air cooling to improve the heat dissipation efficiency of the motor, but also optimizes the water cooling flow channel 7 on the motor casing 3 and the cooling air channel in the motor, further improving the overall heat dissipation of the motor from the structure efficiency, and can also complete the heat conduction and heat dissipation of the thrust bearing 4, and the heat dissipation efficiency is high.

Claims (9)

1. The cooling structure of the magnetic suspension centrifugal compressor motor is characterized in that the motor comprises a rotor, a stator and a shell which are sleeved in sequence, and a heat dissipation gap is arranged between the rotor and the stator in a separation mode; the stator is fixed on the inner wall of the shell, the two ends of the stator are respectively provided with a heat dissipation area communicated with the heat dissipation gap, and the shell is fixedly provided with an air inlet and an air outlet communicated with the heat dissipation area; the shell is internally provided with a water cooling flow passage, and the shell is fixedly provided with a water inlet and a water outlet which are communicated with the water cooling flow passage.

2. The cooling structure of claim 1, wherein a thrust bearing is disposed at one end of the rotor, and a heat dissipation hole communicating with the heat dissipation area is disposed on a spacer of the thrust bearing.

3. The cooling structure of claim 2, wherein the front end of the housing is provided with a front end magnetic bearing seat, a front end radial magnetic bearing is arranged in the front end magnetic bearing seat, and a heat dissipation air port communicated with the heat dissipation area is arranged in the front end magnetic bearing seat and communicated with the heat dissipation area.

4. The cooling structure of a magnetic levitation centrifugal compressor motor according to claim 1, wherein the housing is an aluminum stretching profile motor cylinder, and both ends of the housing are sealed by friction stir welding.

5. The cooling structure of claim 1, wherein the air inlet is located opposite to the coil on the stator.

6. A cooling structure of a magnetic levitation centrifugal compressor motor according to claim 1 or 4, wherein the water-cooling flow passage comprises a plurality of axial flow passages arranged parallel to the axis of the housing, the axial flow passages being connected in series with each other.

7. The cooling structure of claim 6, wherein the axial flow channels are twelve arranged in a circumferential array around the axis of the casing, the radial cross section of the axial flow channels is circular arc, and the central angle of the radial cross section of the axial flow channels is 20 to 27 degrees.

8. A cooling structure of a magnetic suspension centrifugal compressor motor according to claim 3, wherein the air inlet is arranged at the front end of the motor housing, the thrust bearing is arranged in the end part of the front magnetic bearing seat, and the heat dissipation hole is communicated with the heat dissipation air inlet.

9. A cooling structure of a magnetic levitation centrifugal compressor motor according to claim 1 or 2 or 3 or 5 or 8, wherein the length of the air inlet in the axial direction of the motor ranges from 1/4 to 2/5 of the axial length of the stator.

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