A magnetically suspended centrifugal compressor

Abstract

The present invention discloses a magnetic levitation centrifugal compressor, which belongs to the field of compressor equipment, including a magnetic levitation motor assembly, wherein an interpolar cooling device is connected between a primary volute and a secondary volute at both ends of the magnetic levitation motor assembly through a first air pipe and a second air pipe; the air inlet diameter of the first air pipe is the same as the air outlet diameter of the second air pipe. The air inlet diameter of the first air pipe and the air outlet diameter of the second air pipe are the same or as close as possible to minimize noise reduction, and the interpolar cooling device of the first air pipe and the second air pipe can cool the air compressed for the first time, which can effectively reduce the temperature of the compressed air, thereby reducing the pressure of the gas flowing into the second air pipe, and can also effectively reduce the pressure difference between the intake air pressure and the exhaust air pressure, which is beneficial to noise reduction. In addition, the present invention has lower energy consumption, high air filtration accuracy, and a balanced structure of the internal rotating shaft of the compressor, which can reach a higher rotation speed, and better gas compression effect and product quality.

Description

Technical Field

[0001] The present invention relates to a compressor, and more particularly to a magnetic suspension centrifugal compressor. Background Art

[0002] With the development of science and technology, compressors are increasingly used in people's daily lives, so the requirements for compressors are getting higher and higher. Existing compressors are prone to generate noise when working. The reasons for the noise include the following: Since the compressed air contains foreign particles, when the compressor is working, the foreign particles enter the compressor parts, causing wear between the parts and generating noise; the pressure difference between the compressor's intake and exhaust is large, resulting in an unbalanced rotational torque of the compressor, which causes the compressor to generate noise. Compressor noise can cause serious damage to the compressor body, so when designing and developing a compressor, it is necessary to focus on the impact of compressor noise.

[0003] For example: Chinese patent announcement number CN 214366778, announcement date October 8, 2021, the name of the utility model is a magnetic levitation centrifugal compressor unit system, which includes a magnetic levitation centrifugal compressor main unit, a magnetic levitation centrifugal compressor main unit cooling fan and a cooler. The magnetic levitation centrifugal compressor main unit includes a magnetic levitation motor and a centrifugal impeller volute. This solution controls the power of the AC motor by changing the operating frequency of the motor through a variable frequency control system, and provides the power supply voltage according to the actual needs of the motor, which has the advantage of energy saving. However, it cannot effectively remove impurities inside the compressed air, and the condensed water generated by the high-temperature gas compressed by the compressor is easily retained inside the compressor after being cooled by the cooling pipe, causing the compressed gas to contain moisture, which is easy to damage the parts inside the compressor and cause the compressor to generate noise. A silencer structure is required to reduce noise. Summary of the invention

[0004] The present invention overcomes the problem that when the existing compressor is working, the compressor vibrates and generates noise due to impurities in the compressed air or unstable air pressure, and provides a magnetic levitation centrifugal compressor. This scheme removes impurities in the air through graded filtration, and ensures that the pressure difference between the compressor intake and exhaust is not too large through a cooling device and an anti-surge device, thereby effectively reducing the noise generated by the compressor.

[0005] In order to solve the above technical problems, the present invention adopts the following scheme: a magnetic levitation centrifugal compressor, including a magnetic levitation motor assembly, wherein an interpolar cooling device is connected between the first volute and the second volute at both ends of the magnetic levitation motor assembly through a first air pipe and a second air pipe; the air inlet diameter of the first air pipe is the same as the air outlet diameter of the second air pipe. In this scheme, after the gas passes through the first volute and the second volute, it will be compressed twice. During the flow of the gas, the noise will be greater due to the excessive pressure difference between the intake air pressure and the exhaust air pressure. An intake and exhaust process is formed between the first air pipe, the interpolar cooling device and the second air pipe. Therefore, the intake diameter of the first air pipe and the air outlet diameter of the second air pipe are the same or as close as possible to minimize noise, and the interpolar cooling device of the first air pipe and the second air pipe can cool the air compressed for the first time, which can effectively reduce the temperature of the compressed air, thereby reducing the pressure of the gas flowing into the second air pipe, and can also effectively reduce the pressure difference between the intake air pressure and the exhaust air pressure, which is conducive to noise reduction.

[0006] Preferably, the diameter of the first air pipe gradually increases from the primary volute to the interpolar cooling device, and the second air pipe is connected to the interpolar cooling device and the secondary volute in the form of a C-shaped elbow. After passing through the primary volute, the gas is compressed and enters the first air pipe. The diameter of the first air pipe gradually increases, so that the pressure of the compressed gas gradually decreases and the flow rate slows down. Then, it enters the interpolar cooling device, which is conducive to the cooling of the compressed gas. After the compressed gas is cooled, it enters the second air pipe. The C-shape of the second air pipe can make the advection gas reverse, reduce the flow rate of the gas to a certain extent to prevent vortex, and then enter the secondary volute.

[0007] Preferably, the inter-pole cooling device comprises an air inlet cavity, a cooling cavity and an air outlet cavity, the aperture of the air inlet cavity gradually increases from the first air pipe to the cooling cavity and is in a curved tube structure, and the aperture of the air outlet cavity gradually decreases from the cooling cavity to the second air pipe and is larger than the aperture of the second air pipe. The gas enters the air inlet cavity, the cooling cavity and the air outlet cavity of the inter-pole cooling device from the first air pipe in sequence, the aperture of the air inlet cavity gradually increases from the first air pipe to the cooling cavity and the air inlet cavity is in a curved tube structure, which is conducive to further reducing the speed of the gas output from the first air pipe to prevent vortex, and is conducive to the cooling cavity to fully cool the gas and reduce the kinetic energy of the gas; the aperture of the air outlet cavity gradually decreases from the cooling cavity to the second air pipe and is larger than the aperture of the second air pipe. After the gas enters the air outlet cavity from the cooling cavity, the diameter of the air outlet cavity gradually decreases, which can increase the pressure of the gas entering the air outlet cavity and avoid pressure loss caused by too large diameter change.

[0008] Preferably, the cooling chamber of the inter-electrode cooling device is provided with a circulating cooling water pipe and an inter-electrode water-cooling radiator, the circulating cooling water pipe is arranged in a curved form inside the cooling chamber, and the inter-electrode water-cooling radiator is arranged on the wall of the cooling chamber. The circulating cooling water pipe in the cooling chamber is arranged in a curved form, which is conducive to the circulating cooling water pipe occupying more cooling area in the cooling chamber, which is conducive to the cooling of the gas. The inter-electrode water-cooling radiator is arranged on the wall of the cooling chamber, which can assist the circulating cooling water pipe in cooling together, ensuring the full range of cooling of the gas in the cooling chamber.

[0009] Preferably, the air outlet cavity of the interpolar cooling device is provided with a water baffle, the height of which is not lower than the center of the hole of the air inlet of the second air pipe; a drain port is provided at the bottom of the interpolar cooling device on the side of the water baffle away from the second air pipe, and the drain port is connected to an automatic drainer. After the gas is compressed for the first time, the temperature of the gas rises, and condensed water is generated in the gas after being cooled in the cooling cavity. A water baffle is provided in the air outlet cavity. When the gas hits the water baffle, the water in the gas will remain on the water baffle and condense into water droplets. Therefore, a drain port needs to be provided at the bottom of the interpolar cooling device on the side of the water baffle away from the second air pipe to drain the condensed water. The automatic drainer is connected to the drain port, and the condensed water can be discharged to the outside of the compressor.

[0010] Preferably, the first-stage volute is connected to a graded filtering device, and the graded filtering device is provided with an air inlet filter, a primary filter and a medium-efficiency filter in sequence from the air inlet to the filter chamber, and a plurality of high-efficiency filters are provided inside the filter chamber, and the high-efficiency filters are hollow cylindrical and connected to the air supply chamber of the graded filtering device. The filtering device is connected to the first-stage volute, and the graded filtering device is mainly used to filter particulate impurities and moisture in the air. Multi-stage filtration is arranged from the total air inlet to the filter chamber of the graded filtering device, and impurities in the air are filtered out step by step, and finally the final filtration is completed by the high-efficiency filter inside the filter chamber, which can remove impurities with a particle diameter greater than 3um in the air, and the removal rate can reach 99.99%, which is beneficial to ensure gas quality and product quality, and can also prevent the internal structure of the compressor from being worn due to impurities, resulting in reduced life or noise.

[0011] Preferably, an end cap is provided at one end of the high efficiency filter, and the end cap is connected to the top of the "X"-shaped fixing frame through a connector, and a block is provided at the other end of the high efficiency filter, and the block is connected to the bottom of the "X"-shaped fixing frame and a sealing stop block. The side wall of the high efficiency filter can filter air, and an end cap is provided at one end, and a connecting hole is provided at the center of the end cap and the top of the "X"-shaped fixing frame. The end cap and one end of the high efficiency filter can be connected by a connector such as a bolt, and an axial block is provided at the other end of the high efficiency filter, and the block is connected to the groove at the bottom of the "X"-shaped fixing frame. At the same time, a sealing stop block is installed to completely fix the high efficiency filter.

[0012] Preferably, the outer wall of the sealing limit block is a radial sealing surface, and an end face sealing surface is provided on the convex block at the joint between the sealing limit block and the bottom of the "J" shape. The sealing limit block is clamped between the outer wall of the "J" shape fixing frame and the inner wall of the high-efficiency filter block, and the radial sealing surface fits with the inner wall of the block, and the end face sealing surface fits with the end of the block. The sealing limit block and the high-efficiency filter are both hollow cylindrical, and the side wall of the sealing limit block fits with the inner wall of the block of the high-efficiency filter to achieve radial sealing. The convex block of the sealing limit block is provided with an end face sealing surface and fits with the end of the block of the high-efficiency filter to achieve end face sealing. The radial sealing and end face sealing can ensure the sealing of the filter cavity, prevent impurities from entering the compressor and causing damage to internal parts, and also have a certain effect on preventing noise.

[0013] Preferably, an S-shaped water flow channel is provided inside the shell of the magnetic levitation motor assembly, and the water inlet and water outlet of the water flow channel are connected to the water inlet and water outlet of the circulating cooling water pipe through the first water pipe and the second water pipe respectively. The diameters of the first water pipe and the second water pipe are equal and smaller than the diameters of the water outlet and the water inlet pipe. The water inlet pipe is provided with a cut-off plate downstream of the first water pipe in the direction of water flow. An S-shaped water flow channel is provided inside the shell of the magnetic levitation motor assembly for cooling the outer surface of the motor stator. The water inlet and water outlet of the water flow channel are both on the surface of the shell, and are connected to the water inlet and water outlet of the circulating cooling water pipe through the first water pipe and the second water pipe, that is, while the circulating cooling water pipe cools the internal compressed gas, part of the water will enter the shell through the first water pipe and the second water pipe to cool the outer surface of the motor stator, reducing one water supply device; the diameters of the first water pipe and the second water pipe are equal and smaller than the diameters of the water outlet and the water inlet pipe. Due to the water inlet The pipe has a larger diameter, and the water pressure inside will be greater than the water pressure in the first water pipe with a smaller diameter, so that water can enter the first water pipe smoothly. However, it is also necessary to set a cutoff piece at the position after the water inlet pipe flows through the first water pipe in the direction of water flow. The cutoff piece can reduce the water pressure after the cutoff, so that the first water pipe can obtain a higher water pressure, and the water can flow from the first water pipe to the second water pipe and finally return to the outlet pipe. At the same time, since the water pressure of the water after the cutoff is reduced, its kinetic energy is reduced, and the temperature is also reduced, which plays a better role in the cooling effect of the circulating cooling water pipe.

[0014] Preferably, the housing of the magnetic levitation motor assembly is also provided with a motor heat dissipation air inlet and a motor heat dissipation air outlet, the motor heat dissipation air inlet is connected to the air supply cavity through a heat dissipation fan and an air pipe, and the motor heat dissipation air outlet is connected to the first labyrinth-shaped sound insulation channel through an air pipe. The gas in the air supply cavity can be transported to the motor heat dissipation air inlet through the heat dissipation fan, and the gas enters the motor from the motor heat dissipation air inlet to cool the motor rotor, the coil and the inner ring of the motor stator, and finally the gas is discharged from the motor heat dissipation air outlet into the first labyrinth-shaped sound insulation channel, and finally discharged to the outside of the compressor; the connection to the first labyrinth-shaped sound insulation channel is mainly for noise reduction, and the side walls of the first labyrinth-shaped channel are made of sound insulation cotton.

[0015] Preferably, the magnetic suspension motor assembly includes a magnetic suspension shaft, a primary impeller is provided at one end of the magnetic suspension shaft close to the primary volute, a secondary impeller is provided at the other end, and a bearing block is provided near the primary impeller at the magnetic suspension bearing, and thrust bearings are provided on both sides of the bearing block. The primary impeller and the secondary impeller can perform primary and secondary compression on the gas to ensure the required pressure of the compressed gas. At the same time, the primary impeller and the secondary impeller are provided on the magnetic suspension shaft to offset the axial force generated by the two impellers on the magnetic suspension shaft, thereby ensuring that the compressor reaches a higher speed and is applicable to higher requirements. The magnetic suspension shaft at the end of the primary impeller is provided with a thrust bearing, and the number of thrust bearings is two. The two thrust bearings are installed on both sides of the bearing block, and the two thrust bearings are connected and fixed by a connector. The thrust bearing can also play a certain positioning role in the axial direction of the magnetic suspension shaft, and the bearing block can position the thrust bearing.

[0016] Preferably, the magnetic suspension motor assembly further comprises a primary bearing seat and a secondary bearing seat, and a primary diffuser and a secondary diffuser are respectively arranged between the primary bearing seat and the primary volute, and between the secondary bearing seat and the secondary volute, and the primary diffuser and the secondary diffuser are respectively connected to the primary impeller and the secondary impeller through a plurality of matching annular sealing teeth and annular tooth grooves thereon. The primary diffuser and the secondary diffuser can increase the pressure of the gas compressed twice, and annular sealing teeth and annular tooth grooves are arranged between the back of the primary impeller and the primary diffuser. Under the high-speed rotation of the magnetic suspension, the annular sealing teeth and the annular tooth grooves can form a sealing structure, and the sealing strength depends on the number of annular sealing teeth and annular tooth grooves, and the number should be not less than 8, and one of the annular sealing teeth and annular tooth grooves is arranged on the primary impeller, and the other is arranged on the primary diffuser; there is also the same annular sealing teeth and annular tooth groove structure between the secondary impeller and the secondary diffuser, which also plays a sealing role.

[0017] Preferably, the edge of the first-stage impeller is provided with a first annular pressure regulating device, the edge of the second-stage impeller is provided with a second annular pressure regulating device, and the first annular pressure regulating device and the second annular pressure regulating device are both located at the outer edges of the annular sealing teeth and the annular tooth grooves. The first annular pressure regulating device is the outer ring part of the first-stage impeller outside the annular sealing teeth and the annular tooth groove structure, and the second annular pressure regulating device is the outer ring part of the second-stage impeller outside the annular sealing teeth and the annular tooth groove structure; according to actual working needs and working environment, by calculating the pressure and thrust of the first annular pressure regulating device and the second annular pressure regulating device, and then by adjusting the first pressure regulating radial length of the first annular pressure regulating device and the second pressure regulating radial length of the second annular pressure regulating device, the axial force balance of the magnetic suspension shaft can be achieved.

[0018] Preferably, the secondary volute is also connected to an anti-surge device through a third air pipe, and the anti-surge device includes a conical exhaust pipe, the aperture of which gradually increases from the air inlet end to the air outlet end, and the air outlet end is provided with a switch type vent valve, the air inlet end is provided with an adjustable vent valve, and an exhaust pressure sensor is provided on the conical exhaust pipe between the two. After passing through the secondary volute, the gas is compressed for the second time, and then enters the conical exhaust pipe through the third air pipe. There is also a bend structure connection between the third air pipe and the conical exhaust pipe, which can effectively prevent the gas from generating vortexes due to excessive flow rate. The aperture of the conical exhaust pipe gradually increases from the air inlet end to the air outlet end, which is conducive to the gradual pressure reduction of the compressed gas, preventing surge and noise. The outlet end of the conical exhaust pipe is provided with a switch-type vent valve, and the inlet end is provided with an adjustable vent valve. The switch-type vent valve is in a normally closed state. When the pressure inside the conical exhaust pipe is too high, the switch-type vent valve can be opened to release the pressure and play a protective role. When surge occurs or the compressor is started and stopped, the adjustable vent valve will open to prevent surge and noise. The exhaust pressure sensor is used to detect the pressure change in the conical exhaust pipe.

[0019] Preferably, the conical exhaust pipe is connected to the main exhaust pipe through a one-way valve, and a system pressure sensor is provided on the main exhaust pipe; the main exhaust pipe is connected to the outside, and the switch-type vent valve and the adjustable vent valve are connected to the second labyrinth-shaped soundproof channel. The system pressure sensor is used to detect the pressure in the main exhaust pipe. When the pressure detected by the exhaust pressure sensor is greater than the pressure detected by the system pressure sensor, the one-way valve will open to perform exhaust operation; when the pressure detected by the system pressure sensor is greater than the pressure detected by the exhaust pressure sensor, the adjustable vent valve will open to perform air pressure balance operation. The switch-type vent valve and the adjustable vent valve are connected to the second labyrinth-shaped soundproof channel through a pipeline. The second labyrinth-shaped soundproof channel is also used to perform silencing during exhaust. The side walls of the second labyrinth-shaped soundproof channel are also made of sound-absorbing materials such as soundproof cotton.

[0020] Preferably, a magnetic levitation centrifugal compressor also includes an air inlet and a negative pressure chamber in the box, wherein the air inlet in the box is provided with a multi-layer filter, the air inlet in the box is connected to the air inlet of the negative pressure chamber, and the air outlet of the negative pressure chamber is connected to the filter chamber. The air inlet in the box is connected to the external air, and the external air enters the compressor box after passing through the multi-layer filter to cool the structure inside the box. Since the air outlet of the negative pressure chamber is connected to the filter chamber, and the gas in the filter chamber will quickly flow into the air supply chamber under the action of the heat dissipation fan and the compressor, a negative pressure will be formed in the negative pressure chamber. The gas in the compressor box will enter the negative pressure chamber under the action of the pressure difference, and then enter the internal air path structure of the compressor under the action of the high-efficiency filter. Through the negative pressure chamber, the use of a heat dissipation motor can be reduced, the failure rate is reduced, and the energy efficiency of the equipment is improved.

[0021] Preferably, a magnetic levitation centrifugal compressor further includes an assembled base, the assembled base includes a plurality of square tube outer frames and a plurality of square tube channel steels, the square tube outer frames are connected by angle steels, the square tube channel steels and the square tube outer frames are staggered and connected by fixing members. The assembled base adopts a square tube combination connection, which reduces the welding process, and the square tube painting operation can also be completed in advance, shortening the production cycle, and the assembled base is also convenient for maintenance and replacement.

[0022] Compared with the prior art, the present invention has the following beneficial effects: (1) it can more effectively reduce noise and prevent surge; (2) the magnetic suspension shaft can achieve axial force balance, and the compressor can reach a higher speed; (3) it adopts a combination of air cooling and water cooling, and all water cooling requires only one water supply source; (4) the filtering device adopts a graded filtering form, with high filtering accuracy and good filtering effect; (5) it reduces the use of heat dissipation power devices and water source power devices, thereby improving the energy efficiency of the equipment; (6) the sealing effect is higher, the pollution rate of compressed gas is reduced, and the product quality is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structural distribution of the present invention.

[0024] Figure 2 It is a schematic diagram of the inter-electrode cooling device of the present invention.

[0025] Figure 3 It is a schematic diagram of the graded filtration device, the high efficiency filter and the sealing limit block of the present invention.

[0026] Figure 4 It is a cross-sectional view of the internal structure of the motor assembly of the present invention.

[0027] Figure 5 It is a schematic diagram of the housing structure of the motor assembly of the present invention.

[0028] Figure 6 It is a schematic structural diagram of the anti-surge device of the present invention.

[0029] Figure 7 It is a schematic diagram of the assembled base of the present invention.

[0030] Figure 8 It is an axonometric view of the internal structure of the whole machine of the present invention.

[0031] In the figure: 1. Magnetic levitation motor assembly, 2. First-stage volute, 3. Second-stage volute, 4. First air pipe, 5. Second air pipe, 6. Third air pipe, 7. Interpolar cooling device, 9. Air inlet cavity, 10. Cooling cavity, 11. Air outlet cavity, 12. Circulating cooling water pipe, 13. Interpolar water cooling radiator, 14. Water baffle, 15. Drain, 16. Automatic drain, 18. Air inlet, 19. Filter cavity, 20. Air inlet filter, 21. Primary filter, 22. Medium filter, 23. High efficiency filter, 24. Air supply cavity, 25. End cover, 26. I-shaped fixing bracket, 27. Connector, 28. Block, 29. Sealing stopper, 30. Radial sealing surface, 31. End sealing surface, 32. Housing, 33. Water channel, 34. Water inlet of water channel, 35 .Water outlet of water channel, 36.First water pipe, 37.Second water pipe, 38.Water inlet pipe, 39.Water outlet pipe, 40.Interceptor, 41.Motor cooling air inlet, 42.Motor cooling air outlet, 43.Cooling fan, 44.Air pipe, 45.First labyrinth-shaped soundproof channel, 46.Magnetic suspension shaft, 47.First impeller, 48.Second impeller, 49.Bearing block, 50.Thrust bearing, 51. First-stage bearing seat, 52. Second-stage bearing seat, 53. First-stage diffuser, 54. Second-stage diffuser, 55. Annular sealing teeth, 56. Annular tooth grooves, 57. First annular pressure regulation, 58. Second annular pressure regulation, A. Radial length of first pressure regulation, B, radial length of second pressure regulation, 60. Conical exhaust pipe, 61. Inlet end, 62. Outlet end, 63. Switch-type vent valve, 64. Adjustable vent valve, 65. Exhaust pressure sensor, 66. One-way valve, 67. Main exhaust pipe, 68. System pressure sensor, 69. Second labyrinth-shaped sound insulation channel, 70. Air inlet in the box, 71. Negative pressure chamber, 72. Multi-layer filter, 73. Negative pressure chamber air inlet, 74. Negative pressure chamber air outlet, 75. Assembled base, 76. Square outer frame, 77. Square channel steel, 78. Angle steel, 79. Fixing parts, 80. Radiator. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0033] Example 1: Figures 1 to 6A magnetic levitation centrifugal compressor shown includes a magnetic levitation motor assembly 1, a first-stage volute 2 and a second-stage volute 3 are provided at both ends of the magnetic levitation motor assembly 1, an inter-pole cooling device 7 is connected between the first-stage volute 2 and the second-stage volute 3 via a first air pipe 4 and a second air pipe 5, wherein the air inlet of the first air pipe 4 and the air outlet of the second air pipe 5 have the same diameter, or the air inlet diameter of the first air pipe 4 is slightly smaller than the air outlet diameter of the second air pipe 5, because the overall noise of the compressor decreases with the increase of the suction pressure and increases with the increase of the exhaust pressure, the pressure difference between the suction pressure and the exhaust pressure becomes smaller, which can reduce the unbalanced torque of the compressor shaft, thereby reducing the noise. The diameter of the first air pipe 4 gradually increases from the first-stage volute 2 to the inter-electrode cooling device 7. When the gas flows into the first air pipe 4 after the first compression, the diameter of the first air pipe 4 gradually increases, which is beneficial to the pressure reduction and speed reduction of the compressed gas, and can also avoid the noise caused by excessive pressure and excessive flow rate to a certain extent. The second air pipe 5 is a C-shaped pipe. On the one hand, the C-shaped pipe can make full use of the space inside the compressor compared to the straight pipe, and can make the horizontal flow of gas reverse, thereby reducing the flow rate of the gas to a certain extent to prevent vortexes.

[0034] The inter-pole cooling device 7 is connected between the first air pipe 4 and the second air pipe 5 , and is provided with an air inlet cavity 9 , a cooling cavity 10 and an air outlet cavity 11 along the air flow direction. The air inlet cavity 9 is connected to the first air pipe 4, and the aperture of the air inlet cavity 9 gradually increases from the first air pipe 4 to the cooling cavity 10 and is in a curved pipe structure, which is beneficial to slow down the gas output from the first air pipe 4 to prevent eddy currents, and is beneficial to fully cool the gas in the cooling cavity 10 and reduce the kinetic energy of the gas; a circulating cooling water pipe 12 and an inter-pole water-cooling radiator 13 are arranged inside the cooling cavity 10, and the circulating cooling water pipe 12 is passed from the outside into the inter-pole cooling device 7 and is arranged in a curved and surrounding manner inside the cooling cavity 10. The curved and surrounding arrangement of the circulating cooling water pipe 12 inside the inter-pole cooling device 7 can increase the effective cooling area, so that the compressed gas can be fully cooled. At the same time, the inter-pole water-cooling radiator 13 is arranged on the cavity wall of the cooling cavity 10, and can cool the compressed gas in the entire range; the aperture of the air outlet cavity 11 gradually decreases from the cooling cavity 10 to the second air pipe 5, but its minimum aperture is still larger than the aperture of the second air pipe 5, and the diameter of the air outlet cavity 11 gradually decreases. To increase the gas pressure and reduce the pressure loss; because the temperature of the gas increases after the gas is compressed once, condensed water will be generated in the gas after passing through the cooling chamber 10, so a water baffle 14 is also provided in the air outlet chamber 11, and one end of the water baffle 14 has a slot and is snapped to the bottom of the air outlet chamber 11. The top height of the water baffle 14 is not lower than the center position of the air inlet hole of the second air pipe 5. The water baffle 14 can block the air inlet of the second air pipe 5 as much as possible, and most of the gas will pass through the water baffle 14, leaving the condensed water in the gas on the water baffle 14. After the condensed water gathers into water droplets, it will slide along the water baffle 14 to the drain port 15 at the bottom. The drain port 14 is connected to the automatic drainer 16, and the water can be discharged to the outside of the compressor in the end. After most of the water in the gas is removed, the impurity rate of the compressed gas can be reduced, and the quality of the product can be improved. At the same time, the condensed water will not cause rust or damage to the internal equipment, thereby improving the life of the equipment.

[0035] The graded filtering device is connected to the first-stage volute 2, and an air inlet filter 20, a primary filter 21 and a medium-efficiency filter 22 are sequentially arranged from the air inlet 18 to the filter chamber 19 of the graded filtering device; the air inlet filter 20 can perform a preliminary filtration on the air to remove larger impurity particles in the air, the primary filter 21 can remove particle impurities larger than 10um, and the removal rate can reach 80%, the medium-efficiency filter 22 can remove particle impurities larger than 5um, and the removal rate can reach more than 90%, and a number of high-efficiency filters 23 are also arranged in the filter chamber 19 inside the graded filtering device, and the high-efficiency filter 23 can remove particle impurities larger than 3um, and the removal rate can reach 99.99%. The high efficiency filter 23 is in the shape of a hollow column and is provided with an end cover 25 at one end close to the air inlet 18. The end cover 25 is connected to the top of an "X"-shaped fixing frame 26 by bolts or other connecting pieces 27. The other end of the high efficiency filter 23 is provided with a block 28. The block 28 is engaged with a sealing limit block 29 in a notch at the bottom of the "X"-shaped fixing frame 26. The "X"-shaped fixing frame 26 is fixed to the partition in the compressor housing, so that the high efficiency filter 23 can be fixed. The sealing limit block 29 is engaged between the "X"-shaped fixing frame 26 and the high efficiency filter 23. The sealing limit block 29 is engaged between the "X"-shaped fixing frame 26 and the high efficiency filter 23. The radial sealing surface 30 on the outer side of the positioning block 29 is in contact with the inner wall of the card block 28, and the end face sealing surface 31 on the protrusion of the sealing limit block 29 is in contact with the end of the card block 28; since the "X"-shaped fixing frame 26 is not cylindrical, the space between the high-efficiency filter 23 and the air supply cavity 24 needs to be sealed. The radial sealing and end face sealing of the hollow cylindrical sealing limit block 29 can ensure a good seal between the filter cavity 19 and the air supply cavity 24, prevent foreign particles from entering the compressor, causing damage to the internal parts and reducing the life of the compressor.

[0036] During operation, the internal parts of the magnetic levitation motor assembly 1 also need to be cooled, and this solution uses both water cooling and air cooling to achieve this. Water cooling part: An S-shaped water channel 33 is provided inside the housing 32 of the magnetic levitation motor assembly 1, and all water channels 33 are connected in series. The water channel inlet 34 and the water channel outlet 35 are connected to the first water pipe 36 and the second water pipe 37 respectively. The first water pipe 36 and the second water pipe 37 are connected to the water inlet pipe 38 and the water outlet pipe 39 of the circulating cooling water pipe 12 respectively. While water is used to cool the air inside the inter-pole cooling device 7, water can also be introduced into the motor housing 32 to cool the outer surface of the motor stator. In order to allow the water to be smoothly diverted into the first water pipe 36, the water inlet pipe 39 is connected to the first water pipe 36. The water pressure in 38 needs to be greater than the water pressure in the first water pipe 36, so the diameter of the first water pipe 36 needs to be smaller than the diameter of the water inlet pipe 38. For the convenience of work and the convenience of water pipe processing, the diameters of the first water pipe 36 and the second water pipe 37 can be made the same, and the diameters of the water outlet pipe 38 and the water inlet pipe 39 can be made the same; in order to ensure that after the water is diverted into the first water pipe 36, it can also enter the S-shaped water flow channel 33 inside the motor housing 32, and finally flow out from the second water pipe 37 to the water outlet pipe 39 to form a loop, a diverter 40 should be set at the position where the water inlet pipe 38 follows the direction of the water flow and passes through the first water pipe 36. The intercepting piece 40 can reduce the water pressure in the water channel behind, so that the first water pipe 36 can obtain a larger water pressure, that is: the pressure of the water inlet pipe 38 = the pressure of the first water pipe 36 + the water pressure after interception (near the water inlet pipe 38) = the water pressure of the second water pipe 37 + the water pressure after interception (near the water outlet pipe 39) = the water pressure of the water outlet pipe 39; at the same time, the water pressure and kinetic energy of the intercepted water are reduced, so it is often accompanied by a cooling phenomenon, which has a better effect on cooling the gas inside the inter-electrode cooling device 7. Air cooling part: The housing 32 of the magnetic levitation motor assembly 1 is provided with a motor heat dissipation air inlet 41 and a motor heat dissipation air outlet 42. A heat dissipation fan 43 is provided between the motor heat dissipation air inlet 41 and the air supply cavity 24 through an air pipe 44. The heat dissipation fan 43 can transport the gas in the air supply cavity 24 to the motor heat dissipation air inlet 42, enter the motor, cool the motor rotor, the coil and the inner ring of the motor stator, and then enter the first labyrinth-shaped sound insulation channel 45 through the motor heat dissipation air outlet 43, and finally discharge into the air. Among them, since the gas entering the interior of the high-efficiency filter 23 includes the outside air and the hot air inside the negative pressure cavity 71, a radiator 80 is also provided in the air supply cavity 24, and the radiator 80 is arranged between the high-efficiency filter 23 and the entrance of the air pipe 44; wherein the first labyrinth-shaped sound insulation channel 45 is made of sound insulation materials such as sound insulation cotton, which is conducive to reducing the noise of the compressor. During the motor cooling process, only one motor is used for water cooling, which can cool the gas in the inter-electrode cooling device 7 while performing water cooling, thus saving the motor and energy consumption costs.

[0037] The magnetic suspension motor assembly 1 also includes a magnetic suspension shaft 46, a primary bearing seat 50 and a secondary bearing seat 51. A primary impeller 47 is installed near the end of the primary volute 2 of the magnetic suspension shaft 46, and a bearing block 49 is provided on the magnetic suspension shaft 46. A secondary impeller 48 is installed at the other end. A thrust bearing 50 is installed on both sides of the bearing block 49. A primary diffuser 53 is fixed between the primary bearing seat 51 and the primary volute 2, and a secondary diffuser 54 is fixed between the secondary bearing seat 52 and the secondary volute 3. After the gas enters the air delivery cavity 24 from the graded filtering device, it will enter the primary volute 2. Under the action of the primary impeller 47 and the primary diffuser 53, the gas can be compressed for the first time, and then the gas enters the interpolar cooling device 7, and then enters the secondary volute 3 from the second air pipe 5. Under the action of the secondary impeller 48 and the secondary diffuser 54, the gas is compressed for the second time. An impeller is installed at both ends of the magnetic suspension shaft 46, and the impellers are installed relative to each other, which can offset the axial force on the magnetic suspension shaft 46, so that the axial force of the magnetic suspension shaft 46 will not be too large. Due to the effect of the double impellers, the rotation speed of the compressor can reach more than 30,000 revolutions. At the same time, the thrust bearing 50 also has a certain restraining effect on the axial position of the magnetic suspension shaft 46. The two thrust bearings 50 are connected by connecting parts such as screws and axially fixed together with the bearing block 49 to prevent the thrust bearing 50 from axially moving, and also have the effect of offsetting the axial force. An annular sealing tooth 55 and an annular tooth groove 56 are provided between the first-stage diffuser 53 and the back side of the first-stage impeller 47. If one structure is provided with the annular sealing tooth 55, then the other structure is provided with a matching annular tooth groove 56, and the annular sealing tooth 55 and the annular tooth groove 56 can be rotatably connected; the same is true between the second-stage diffuser 54 and the second-stage impeller 48; a first annular pressure regulating device 57 is provided on the edge of the first-stage impeller 47, and the first annular pressure regulating device 57 is arranged on the outer edge of the annular sealing tooth 55 of the first-stage impeller 47; a second annular pressure regulating device 58 is provided on the edge of the second-stage impeller 48, and the second annular pressure regulating device 58 is arranged on the outer edge of the annular sealing tooth 55 of the second-stage impeller 48; the area ratio of the first annular pressure regulating device 57 to the second annular pressure regulating device 58 is inversely proportional to the pressure ratio of the first annular pressure regulating device 57 to the second annular pressure regulating device 58.Under the high-speed rotation of the magnetic suspension shaft 46, the annular sealing teeth 55 and the annular tooth grooves 56 can form a sealing structure, and the sealing performance depends on the number of the annular sealing teeth 55 and the annular tooth grooves 56, and the number should be no less than 8; if the number of the annular sealing teeth 55 and the annular tooth grooves 56 is too small, the sealing effect will not be achieved. The same annular sealing teeth 55 and annular tooth grooves 56 structure are also provided between the secondary impeller 48 and the secondary diffuser 54, which also play a sealing role; in the gas compression process, the first annular pressure regulator 57 and the second annular pressure regulator 58 are the main force-bearing parts. According to the actual working needs and working environment, the pressure and axial thrust of the first annular pressure regulator 57 and the second annular pressure regulator 58 are calculated, and the axial force balance of the magnetic suspension shaft 46 can be achieved by adjusting the first pressure regulator radial length A of the first annular pressure regulator 57 and the second pressure regulator radial length B of the second annular pressure regulator 58.

[0038] The secondary volute 3 is also connected to the anti-surge device through the third air pipe 6, and the anti-surge device includes a tapered exhaust pipe 60, and the aperture of the tapered exhaust pipe 60 gradually increases from the air inlet end 61 to the air outlet end 62; the gas is compressed for the second time after passing through the secondary volute 3, and then enters the tapered exhaust pipe 60 through the third air pipe 6. A bent pipe structure is also provided between the third air pipe 6 and the tapered exhaust pipe 60, which can effectively prevent the gas from generating vortices due to excessive flow rate. The aperture of the tapered exhaust pipe 60 gradually increases from the air inlet end 61 to the air outlet end 62, which is conducive to the gradual decompression of the compressed gas and prevents surge and noise. The outlet end 62 of the conical exhaust pipe 60 is provided with a switch-type vent valve 63, and the inlet end 61 is provided with an adjustable vent valve 64. An exhaust pressure sensor 65 is provided on the conical exhaust pipe 60 between the two. The conical exhaust pipe 60 is connected to the main exhaust pipe 67 through a one-way valve 66. The main exhaust pipe 67 is connected to the outside and is also provided with a system pressure sensor 68. During normal operation, the switch-type vent valve 63 is in a normally closed state, and only the one-way valve 66 is in an open state. When the pressure inside the conical exhaust pipe 60 is too high, the switch-type vent valve 63 can be opened to release the pressure to play a protective role. When surge occurs or the compressor is started and stopped, the air pressure inside the compressor is unstable, and there is a large pressure difference between the gas inlet and outlet. The adjustable vent valve 64 will open to prevent surge and noise. The exhaust pressure sensor 65 is used to detect the pressure change in the conical exhaust pipe 60. When the pressure detected by the exhaust pressure sensor 65 is greater than the pressure detected by the system pressure sensor 68, the one-way valve 66 will open to perform exhaust operation; when the pressure detected by the system pressure sensor 68 is greater than the pressure detected by the exhaust pressure sensor 65, the adjustable vent valve 64 will open to balance the air pressure. When the exhaust pressure in the conical exhaust pipe 60 slowly increases to be greater than the system pressure in the main exhaust pipe 67, the adjustable vent valve 64 will gradually close slowly, so that the compressed gas can smoothly enter the main exhaust pipe 67. This solution can increase the user's ability to predict the pipeline and realize the control of the terminal pressure. The switch-type vent valve 63 and the adjustable vent valve 64 are connected to the second labyrinth-shaped soundproof channel 69 through a pipeline. The second labyrinth-shaped soundproof channel 69 is also used to perform silencing during exhaust. The side wall of the second labyrinth-shaped soundproof channel 69 is also made of soundproof cotton and other soundproof materials.

[0039] An air inlet 70 is also provided on the outer casing of the compressor, and a negative pressure chamber 71 is provided inside. The air inlet 70 is provided with a multi-layer filter 72. The air inlet 73 is connected to the negative pressure chamber air inlet 73 through the inside of the casing, and the air outlet 74 of the negative pressure chamber is connected to the filter chamber 19 of the graded filtering device. The air inlet 70 is connected to the outside air, and the outside air enters the compressor casing after passing through the multi-layer filter 72 to cool the structure inside the casing. Since the air outlet of the negative pressure chamber 71 is connected to the filter chamber 19, and the gas in the filter chamber 19 will quickly flow into the air supply chamber 24 under the action of the heat dissipation fan 43 and the compressor, a negative pressure will be formed in the negative pressure chamber 71. The gas in the compressor casing will enter the negative pressure chamber 71 under the action of the pressure difference, and then enter the internal air path structure of the compressor under the action of the high-efficiency filter 23. Through the negative pressure chamber 71, the use of a heat dissipation motor can be reduced, the failure rate is reduced, and the energy efficiency of the equipment is improved.

[0040] The compressor has air flow and water flow during operation.

[0041] Gas path part: When the compressor is working, the gas passes through the air inlet filter 20, the primary filter 21 and the medium filter 22 of the graded filtering device in turn, and then enters the high-efficiency filter 23 in the filter chamber 19 to complete the final filtration, and then enters the air delivery chamber 24; the gas entering the air delivery chamber 24 will be divided into two parts: ① One part enters the first-stage volute 2, and under the action of the first-stage impeller 47 and the first-stage diffuser 53, it is compressed for the first time, and then enters the air inlet chamber 9, the cooling chamber 10 and the air outlet chamber 11 of the inter-electrode cooling device 7 through the first air pipe 4 in turn, completing the process of deceleration and pressure reduction, cooling, water removal and pressure increase, and then passes ② The other part enters the magnetic suspension motor assembly 1 along the air pipe 44 under the action of the heat dissipation fan 43 to cool the motor, and then enters the first labyrinth-shaped sound insulation channel 45 from the motor heat dissipation outlet 42, and finally is discharged into the atmosphere. There is another air path: when the compressor is working normally, a pressure difference will be formed in the filter chamber 19 and the negative pressure chamber 71, so the gas will also pass through the multi-layer filter 72 of the air inlet 70 in the box to enter the compressor box body, cool the inside of the box body, and then enter the negative pressure chamber 71, and then enter the filter chamber 19 from the negative pressure chamber 71, and then perform the aforementioned air path part.

[0042] Water path part: When the compressor is working, cooling water enters from the water inlet pipe 38, and starts to split when passing through the first water pipe 36. One part enters the cooling chamber 10 of the inter-pole cooling device 7 through the circulating cooling water pipe 12 to cool the gas, and then flows out from the water outlet pipe 39 through the second water pipe 37; the other part enters the S-shaped water flow channel 33 inside the motor housing 32 through the first water pipe 36, and then flows to the second water pipe 37, and is discharged after merging with the first part of the water at the water outlet pipe 39.

[0043] Example 2: Figure 7 and Figure 8 The magnetic suspension centrifugal compressor shown is different from the embodiment 1 only in that an assembled base 75 is also provided at the bottom of the compressor. The assembled base 75 includes a plurality of square tube outer frames 76 and a plurality of square tube channel steels 77. The square tube outer frames 76 are connected by angle steels 78. The square tube channel steels 77 and the square tube channel steels 77 and the square tube outer frames 76 are staggered and connected by fixing members 79. The square tube channel steels 77 are provided with notches, and the square tube channel steels 77 can be connected by notches and then connected by positioning bolts and other structures. The assembled base 75 adopts a square tube combination connection, which reduces the welding process. At the same time, the square tube spray painting operation is simpler and can be completed in advance, shortening the production cycle. The assembled base 75 is also convenient for maintenance and replacement.

Claims

1. A magnetically suspended centrifugal compressor, characterized in that: It includes a magnetic levitation motor assembly, wherein an interpolar cooling device is connected between a primary volute and a secondary volute at both ends of the magnetic levitation motor assembly through a first air pipe and a second air pipe; the air inlet diameter of the first air pipe is the same as the air outlet diameter of the second air pipe; a motor heat dissipation air inlet and a motor heat dissipation air outlet are also provided on the outer shell of the magnetic levitation motor assembly, the motor heat dissipation air inlet is connected with the air supply cavity of the graded filtering device through a heat dissipation fan and an air pipe, and the motor heat dissipation air outlet is connected with the first labyrinth-shaped sound insulation channel through the air pipe; it also includes an air inlet and a negative pressure cavity in the box, the air inlet in the box is connected with the air inlet of the negative pressure cavity, and the air outlet of the negative pressure cavity is connected with the filter cavity of the graded filtering device; multi-stage filtration is arranged from the total air inlet of the graded filtering device to the filter cavity; the gas in the filter cavity forms a negative pressure in the negative pressure cavity under the action of the heat dissipation fan and the compressor, and the gas in the compressor box enters the negative pressure cavity under the action of the pressure difference.

2. A magnetically suspended centrifugal compressor according to claim 1, characterized in that: The diameter of the first air pipe gradually increases from the first-stage volute to the inter-pole cooling device, and the second air pipe is connected to the inter-pole cooling device and the second-stage volute in the form of a C-shaped bend.

3. A magnetically suspended centrifugal compressor according to claim 2, characterized in that: The inter-electrode cooling device includes an air inlet cavity, a cooling cavity and an air outlet cavity. The aperture of the air inlet cavity gradually increases from the first air pipe to the cooling cavity and is a curved pipe structure. The aperture of the air outlet cavity gradually decreases from the cooling cavity to the second air pipe and is larger than the aperture of the second air pipe.

4. A magnetically suspended centrifugal compressor according to claim 3, characterized in that: The cooling cavity of the inter-electrode cooling device is provided with a circulating cooling water pipe and an inter-electrode water-cooling radiator. The circulating cooling water pipe is arranged in a curved form inside the cooling cavity, and the inter-electrode water-cooling radiator is arranged on the cavity wall of the cooling cavity.

5. A magnetically suspended centrifugal compressor according to claim 3 or 4, characterized in that: The air outlet cavity of the inter-pole cooling device is provided with a water baffle, and the height of the water baffle is not lower than the center position of the second air pipe air inlet hole; the bottom of the inter-pole cooling device on the side of the water baffle away from the second air pipe is provided with a drain outlet, and the drain outlet is connected to the automatic drainer.

6. The magnetic suspension centrifugal compressor according to claim 1, characterized in that: The first-stage volute is connected to the graded filtering device, and the graded filtering device is provided with an air inlet filter, a primary filter and a medium-efficiency filter in sequence from the air inlet to the filter chamber. A plurality of high-efficiency filters are provided inside the filter chamber. The high-efficiency filters are hollow columnar and connected to the air supply chamber of the graded filtering device.

7. A magnetically suspended centrifugal compressor according to claim 6, characterized in that: An end cap is arranged at one end of the high efficiency filter, and the end cap is connected to the top of the I-shaped fixing frame through a connecting piece, and a clamping block is arranged at the other end of the high efficiency filter, and the clamping block is clamped with the bottom of the I-shaped fixing frame and the sealing limit block.

8. A magnetically suspended centrifugal compressor according to claim 7, characterized in that: The outer side wall of the sealing limit block is a radial sealing surface, and an end face sealing surface is provided on the convex block where the sealing limit block is clamped with the bottom of the "X"-shaped fixing frame. The sealing limit block is clamped between the outer wall of the "X"-shaped fixing frame and the inner wall of the high-efficiency filter block, the radial sealing surface is in contact with the inner wall of the block, and the end face sealing surface is in contact with the end of the block.

9. A magnetically suspended centrifugal compressor according to claim 4, characterized in that: An S-shaped water channel is provided inside the shell of the magnetic levitation motor assembly. The water inlet and the water outlet of the water channel are connected to the water inlet pipe and the water outlet pipe of the circulating cooling water pipe through the first water pipe and the second water pipe respectively. The diameters of the first water pipe and the second water pipe are equal and smaller than the diameters of the water outlet pipe and the water inlet pipe. The water inlet pipe follows the direction of water flow and is provided with a cut-off plate downstream of the first water pipe.

10. The magnetically suspended centrifugal compressor according to claim 6, characterized in that: A radiator is also arranged in the air delivery cavity, and the radiator is arranged between the high-efficiency filter and the air pipe inlet.

11. The magnetic suspension centrifugal compressor according to claim 1, characterized in that: The magnetic levitation motor assembly includes a magnetic levitation shaft, wherein one end of the magnetic levitation shaft close to the first-stage volute is provided with a first-stage impeller, and the other end is provided with a second-stage impeller. A bearing block is provided near the first-stage impeller of the magnetic levitation shaft, and thrust bearings are provided on both sides of the bearing block.

12. A magnetically suspended centrifugal compressor according to claim 11, characterized in that: The magnetic levitation motor assembly also includes a primary bearing seat and a secondary bearing seat, and a primary diffuser and a secondary diffuser are respectively arranged between the primary bearing seat and the primary volute, and between the secondary bearing seat and the secondary volute, and the primary diffuser and the secondary diffuser are respectively rotatably connected to the primary impeller and the secondary impeller through a plurality of matching annular sealing teeth and annular tooth grooves thereon.

13. A magnetically suspended centrifugal compressor according to claim 12, characterized in that: A first annular pressure regulating device is provided at the edge of the first-stage impeller, and a second annular pressure regulating device is provided at the edge of the second-stage impeller. Both the first annular pressure regulating device and the second annular pressure regulating device are located at the outer edges of the annular sealing teeth and the annular tooth grooves.

14. The magnetically suspended centrifugal compressor according to claim 1, characterized in that: The secondary volute is also connected to the anti-surge device through a third air pipe. The anti-surge device includes a conical exhaust pipe. The aperture of the conical exhaust pipe gradually increases from the air inlet end to the air outlet end. A switch-type vent valve is provided at the air outlet end, and an adjustable vent valve is provided at the air inlet end. An exhaust pressure sensor is provided on the conical exhaust pipe between the two.

15. A magnetically suspended centrifugal compressor according to claim 14, characterized in that: The conical exhaust pipe is connected to the main exhaust pipe through a one-way valve, and a system pressure sensor is provided on the main exhaust pipe; the main exhaust pipe is connected to the outside, and the switch type vent valve and the adjustable vent valve are connected to the second labyrinth-shaped sound insulation channel.

16. The magnetically suspended centrifugal compressor according to claim 1, characterized in that: The air inlet in the box is provided with a multi-layer filter, the air inlet in the box is connected to the air inlet of the negative pressure chamber through the inside of the box body, and the air inlet in the box is connected to the external air.

17. The magnetically suspended centrifugal compressor according to claim 1, characterized in that: It also includes an assembled base, which includes a plurality of square outer frames and a plurality of square channel steels. The square outer frames are connected by angle steels, and the square channel steels and the square channel steels and the square outer frames are staggered and fixedly connected by fixing parts.

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