A magnetic suspension bearing permanent magnet high-speed motor direct-drive water vapor compressor

Abstract

The utility model discloses a kind of magnetic suspension bearing permanent-magnet high-speed motor direct-drive type water vapor compressor, including motor shell, stator, rotor, end cover, volute, isolation ring is equipped between motor shell, volute, the end cover side between the rotor and motor shell is equipped with magnetic suspension bearing one, the impeller side between the rotor and motor shell is equipped with thrust magnetic bearing, magnetic suspension bearing two, flow passage is equipped on magnetic suspension bearing one, stator, thrust magnetic bearing, magnetic suspension bearing two, end cover center is equipped with outlet hole, the impeller side of magnetic suspension bearing two is installed with thrust protection bearing, the impeller side of thrust protection bearing is installed with isolation steam seal, first air cavity is equipped on isolation steam seal, the clearance between first air cavity intercommunication isolation steam seal, rotating shaft;Sealing steam seal is installed between isolation ring, rotating shaft, steam cavity is equipped on sealing steam seal, steam cavity connects the clearance between sealing steam seal, rotating shaft, discharge port is equipped on heat insulation ring.The utility model reduces the operation and maintenance cost of unit.

Description

Technical Field

[0001] This utility model relates to the field of steam compressor technology, and in particular to a direct-drive steam compressor with a magnetic levitation bearing permanent magnet high-speed motor. Background Technology

[0002] With the development of high-speed permanent magnet motors, the application of high-speed motors is becoming increasingly widespread. In particular, active magnetic levitation bearing high-speed motors are increasingly used in engineering applications due to their advantages such as continuously adjustable speed within the full speed range, unlimited bearing speed, unlimited rotor weight, low bearing loss, and maintenance-free operation within the design life cycle.

[0003] Currently, the application of magnetic levitation bearing permanent magnet high-speed motors in engineering is mainly in low-temperature applications such as air compressors and refrigeration compressors, where the medium and motor have good compatibility. Even if the medium leaks into the motor, it will not have an adverse effect on the motor. However, in engineering applications, the temperature of reused water vapor is usually above 80℃, and the water vapor often contains corrosive components. High temperatures are detrimental to motor heat dissipation and can even be harmful. Water vapor can cause corrosion of internal motor components, and corrosive gases can cause irreversible corrosion damage to the motor's internal structure. Therefore, there are currently no application cases of magnetic levitation bearing permanent magnet motors in the water vapor industry. Summary of the Invention

[0004] The purpose of this utility model is to overcome the shortcomings of the existing technology and provide a magnetic levitation bearing permanent magnet high-speed motor direct-drive steam compressor, which reduces unit losses, reduces the unit's footprint, improves factory space utilization, and reduces unit operation and maintenance costs.

[0005] The purpose of this utility model is achieved as follows:

[0006] A direct-drive steam compressor with a magnetic levitation bearing and a permanent magnet high-speed motor includes a motor housing, a stator and a rotor inside the motor housing, an end cover connected to one end of the motor housing, and a volute connected to the other end of the motor housing. The rotor includes a shaft and an impeller, the impeller cooperating with the volute. An isolation ring is provided between the motor housing and the volute to isolate the volute from high temperatures. A first magnetic levitation bearing is provided between the end cover side of the rotor and the motor housing, and a thrust magnetic bearing and a second magnetic levitation bearing are provided between the impeller side of the rotor and the motor housing. The thrust magnetic bearing is adjacent to the stator. The compressor comprises the first magnetic levitation bearing, the stator, the thrust magnetic bearing, and the magnetic levitation bearing. The second floating bearing is provided with a flow channel for cooling air to circulate, and the end cover has an air outlet for cooling air to circulate at the center. The air outlet is connected to the flow channel for cooling air to circulate. A thrust protection bearing is installed on the impeller side of the second magnetic levitation bearing. The thrust protection bearing is matched with the rotating shaft. There is a gap between the thrust protection bearing and the rotating shaft for cooling air to circulate. An isolation steam seal is installed on the impeller side of the thrust protection bearing. The isolation ring is provided with a relief cavity corresponding to the isolation steam seal. The isolation steam seal is matched with the rotating shaft. The isolation steam seal is provided with a first air cavity. The first air cavity is used to introduce cooling air. The first air cavity is connected to the gap between the isolation steam seal and the rotating shaft.

[0007] A sealing steam seal is installed between the isolation ring and the rotating shaft. The sealing steam seal has a steam chamber for introducing steam. The steam chamber connects the gap between the sealing steam seal and the rotating shaft. The heat insulation ring has a discharge port located between the isolation steam seal and the sealing steam seal. The discharge port is used to discharge leaked cooling gas and steam.

[0008] Preferably, a radial protection bearing is installed on the end cap side of the magnetic levitation bearing, the radial protection bearing is fitted with the rotating shaft, and there is a gap between the radial protection bearing and the rotating shaft for cooling air to flow.

[0009] Preferably, a second air cavity is provided between the magnetic bearing 2 and the isolation seal. The second air cavity is used to introduce cooling gas and form a cooling branch. The magnetic levitation bearing 1, the stator, the thrust magnetic bearing, and the magnetic levitation bearing 2 are provided with flow channels that communicate with the cooling branch. The flow channels that communicate with the cooling branch are connected to the air outlet on the end cover. A gap that communicates with the cooling branch is provided between the radial protection bearing and the end cover.

[0010] Preferably, the cooling air is waterless compressed air.

[0011] Preferably, the motor housing is provided with coolant channels, which are arranged corresponding to the stator.

[0012] Preferably, both the isolation seal and the sealing seal are comb-tooth labyrinth seals.

[0013] Due to the adoption of the above technical solution, this utility model has the following beneficial effects:

[0014] (1) Through structural design and material selection, the high-temperature shell is isolated from the motor, thus solving the adverse effects of high-temperature water vapor on the motor;

[0015] (2) By using the double steam seal structure, the medium and the motor are physically isolated, which solves the adverse effects of medium leakage to the motor and motor loss.

[0016] (3) The magnetic levitation bearing is a non-contact bearing, and there is no relative friction between the moving and stationary parts of the rotor, which effectively reduces bearing loss (the loss of conventional sliding bearing is more than 10kw, while the overall loss of magnetic levitation bearing is less than 1kw), thereby improving the overall efficiency of the unit.

[0017] (4) The magnetic levitation bearing is powered by electricity, which does not require a bulky lubrication system, effectively reducing the size of the unit. It also eliminates the power loss of the lubrication system (the lubrication pump usually has a power of more than 3kw), thus improving the overall efficiency of the unit.

[0018] (5) The use of magnetic levitation bearings realizes zero contact between the rotor and stationary parts. Therefore, the unit has no frictional loss, does not need to be disassembled and inspected regularly, and can achieve maintenance-free operation within the design life cycle. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 This is a flow diagram illustrating the sealing and cooling principle of this utility model.

[0021] Figure Labels

[0022] In the attached diagram, 1 is the end cover, 2 is the radial protection bearing, 3 is the first magnetic levitation bearing, 4 is the motor housing, 5 is the stator, 6 is the thrust magnetic bearing, 7 is the second magnetic levitation bearing, 8 is the thrust protection bearing, 9 is the isolation steam seal, 10 is the isolation ring, 11 is the volute, 12 is the rotor, and 13 is the sealing steam seal. Detailed Implementation

[0023] A direct-drive steam compressor with a magnetic levitation bearing and a permanent magnet high-speed motor includes a motor housing 4, within which a stator 5 and a rotor 12 are housed. One end of the motor housing 4 is connected to an end cover 1, and the other end is connected to a volute 11. The rotor 12 includes a shaft and an impeller, the impeller engaging with the volute 11. An isolation ring 10 is provided between the motor housing 4 and the volute 11 to isolate the high temperature of the volute. A magnetic levitation bearing 3 is provided between the end cover side of the rotor 12 and the motor housing 4. A thrust magnetic bearing 6 and a second magnetic levitation bearing 7 are provided between the impeller side of the rotor 12 and the motor housing 4. The thrust magnetic bearing 6 is adjacent to the stator 5. Flow channels for cooling gas are provided on the magnetic levitation bearing 3, the stator 5, the thrust magnetic bearing 6, and the second magnetic levitation bearing 7. In this embodiment, the flow channels for cooling gas are provided... The cooling air flow channel is the gap between the magnetic levitation bearing 1 (3), stator 5, thrust magnetic bearing 6, and magnetic levitation bearing 2 (7). Alternatively, holes can be opened as the cooling air flow channel. The end cover has an air outlet at the center for cooling air to flow out, which is connected to the cooling air flow channel. A thrust protection bearing 8 is installed on the impeller side of magnetic levitation bearing 2 (7). The thrust protection bearing 8 is fitted with the rotating shaft, and there is a gap between the thrust protection bearing 8 and the rotating shaft for cooling air to flow. An isolation steam seal 9 is installed on the impeller side of the thrust protection bearing 8. The isolation ring 10 has a clearance cavity corresponding to the isolation steam seal 9. The isolation steam seal 9 is fitted with the rotating shaft, and a first air cavity is provided on the isolation steam seal 9. The first air cavity is used to introduce cooling air and is connected to the gap between the isolation steam seal 9 and the rotating shaft.

[0024] A sealing steam seal 13 is installed between the isolation ring 10 and the rotating shaft. The sealing steam seal 13 is provided with a steam chamber for introducing steam. The steam chamber connects the gap between the sealing steam seal 13 and the rotating shaft. The heat insulation ring is provided with a discharge port, which is located between the isolation steam seal 9 and the sealing steam seal 13. The discharge port is used to discharge leaked cooling gas and steam.

[0025] A radial protection bearing 2 is installed on the end cap side of the magnetic levitation bearing 3. The radial protection bearing 2 is fitted with the rotating shaft, and there is a gap between the radial protection bearing 2 and the rotating shaft for cooling air to flow.

[0026] A second air cavity is provided between the magnetic bearing 2 7 and the isolation seal 9. The second air cavity is used to introduce cooling air and form a cooling branch. A corresponding cooling air channel is provided on the motor housing 4. The magnetic levitation bearing 1 3, stator 5, thrust magnetic bearing 6, and magnetic levitation bearing 2 7 are provided with flow channels that communicate with the cooling branch. The flow channels that communicate with the cooling branch are connected to the air outlet on the end cover. A gap that communicates with the cooling branch is provided between the radial protection bearing 2 and the end cover 1.

[0027] The cooling gas is anhydrous compressed air. Coolant channels are provided on the motor housing 4, corresponding to the stator. Both the isolation steam seal 9 and the sealing steam seal 13 are comb-tooth labyrinth seals. The steam pressure entering the steam chamber is higher than the compressor outlet pressure, allowing steam to leak to the compressor volute side. The isolation ring 10 has corresponding steam and cooling gas channels.

[0028] Specifically:

[0029] End cap 1 is installed on the motor housing with screws to achieve overall motor sealing; the end cap has a vent with a flange in the center for the exhaust of heat dissipation gas from the motor windings.

[0030] The radial protection bearing 2 is a double angular contact bearing connected to the magnetic bearing by screws, ensuring that the coaxiality of the protection bearing and the magnetic bearing meets the usage requirements.

[0031] The magnetic levitation bearing 3 is mounted to the motor housing with screws, and the bearing body has flow channels for cooling air circulation. A radial displacement sensor is installed on the left side of its winding to monitor the radial displacement of the bearing in real time.

[0032] The motor housing 4 serves as the supporting framework for the entire device, used to install various parts and provide overall support and connection. The motor housing has coolant channels located on the outer surface of the housing at the stator mounting location.

[0033] The stator 5 is installed onto the motor housing by means of heat fitting.

[0034] The thrust magnetic bearing 6 is mounted to the motor housing with screws. It is located between the motor stator and the second magnetic levitation bearing, and on the impeller side. The proximity of the thrust magnetic bearing to the impeller effectively eliminates the change in impeller dynamic-static clearance caused by shaft extension due to high shaft temperature during motor operation, reducing the risk of dynamic-static collision and effectively ensuring design accuracy. The bearing housing has channels for gas cooling.

[0035] The magnetic levitation bearing 7 is connected to the motor housing by screws. A radial displacement sensor is installed on the left side of its winding to monitor the radial displacement of the bearing in real time. There are gas cooling channels on the bearing body.

[0036] The thrust protection bearing 8 employs a double angular contact bearing for protection in case of axial magnetic bearing failure. Axial position sensors are installed on both sides of the bearing near the magnetic levitation bearing for real-time monitoring of the shaft's axial position. The thrust protection bearing is mounted to the magnetic levitation bearing 2 with screws to ensure that the coaxiality of the protection bearing and the magnetic bearing meets the usage requirements.

[0037] The isolation steam seal 9 is installed on the thrust protection bearing body by screws. The isolation steam seal 9 adopts a comb-tooth labyrinth seal, and a first air chamber is provided in the middle of the isolation steam seal 9, which can be introduced with waterless compressed air. When the compressed air is introduced into the first air chamber, it is depressurized by the comb teeth and then leaks to the inside and outside of the motor respectively. The compressed air leaking to the outside of the motor is used to isolate the steam leaking from the steam seal, thereby achieving mutual isolation between the steam and the inside of the motor.

[0038] The isolation ring 10 is made of a material with low thermal conductivity and is used to isolate the high temperature of the volute, keeping the motor housing temperature at a relatively stable low temperature and mitigating the adverse effects of high-temperature steam on motor heat dissipation. The isolation ring is connected to both the motor housing and the volute with screws. The insulation ring body has an internal and externally connected vent (square hole) for the discharge of leaked compressed gas and steam.

[0039] The volute 11 is a steam flow component.

[0040] The rotor 12 consists of magnetic bearing rotor laminations, permanent magnets, sheaths, thrust screw sleeves, impeller tie rods, impellers, and lock nuts mounted on the shaft. It is the only rotating component in the entire equipment.

[0041] The sealing vapor seal 13 is installed on the isolation ring by screws. The sealing vapor seal adopts a comb-tooth labyrinth seal, and a vapor chamber for introducing clean vapor is provided in the middle of the seal. When clean vapor is introduced into the vapor chamber, it leaks to the volute and the external environment through the comb teeth, ensuring the purity of the medium and preventing leakage, and ensuring that the vapor leaked into the environment is non-toxic and harmless.

[0042] Sealed cooling principle:

[0043] 1. Steam with a pressure 20-30 kPa higher than the compressor outlet pressure is introduced into the sealing steam seal 13 to ensure that clean steam leaks to the compressor volute side to achieve zero leakage of the medium, while the steam leaking to the environment side is non-toxic and harmless clean steam.

[0044] 2. Nine points are sealed with anhydrous compressed air at a pressure of 1-2 bar. Part of the air flows into the motor and is eventually discharged through the end cover at the tail of the motor. Part of the air leaks into the environment, preventing the leaked clean steam from flowing into the motor, thus achieving the purpose of isolation and sealing.

[0045] 3. 2-3 bar of anhydrous compressed air is introduced between the magnetic bearing 7 and the isolation seal 9 for cooling the magnetic bearing and the motor stator winding, and finally discharged through the motor tail end cover.

[0046] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of this utility model.

Claims

1. A direct-drive steam compressor with a magnetic levitation bearing permanent magnet high-speed motor, comprising a motor housing, a stator and a rotor disposed within the motor housing, an end cover connected to one end of the motor housing, and a volute connected to the other end of the motor housing, the rotor comprising a shaft and an impeller, the impeller cooperating with the volute, characterized in that: An isolation ring is provided between the motor housing and the volute to isolate the high temperature of the volute. A magnetic levitation bearing I is provided between the end cover side of the rotor and the motor housing. A thrust magnetic bearing and a magnetic levitation bearing II are provided between the impeller side of the rotor and the motor housing. The thrust magnetic bearing is adjacent to the stator. Magnetic levitation bearing I, the stator, the thrust magnetic bearing, and magnetic levitation bearing II are provided with flow channels for cooling air circulation. An air outlet for cooling air circulation is provided in the center of the end cover. The air outlet is connected to the flow channels for cooling air circulation. A thrust protection bearing is installed on the impeller side of magnetic levitation bearing II. The thrust protection bearing is matched with the shaft. There is a gap between the thrust protection bearing and the shaft for cooling air circulation. An isolation steam seal is installed on the impeller side of the thrust protection bearing. The isolation ring is provided with a clearance cavity corresponding to the isolation steam seal. The isolation steam seal is matched with the shaft. The isolation steam seal is provided with a first air cavity for introducing cooling air. The first air cavity is connected to the gap between the isolation steam seal and the shaft. A sealing steam seal is installed between the isolation ring and the rotating shaft. The sealing steam seal has a steam chamber for introducing steam. The steam chamber connects the gap between the sealing steam seal and the rotating shaft. The heat insulation ring has a discharge port located between the isolation steam seal and the sealing steam seal. The discharge port is used to discharge leaked cooling gas and steam.

2. The direct-drive steam compressor with magnetic levitation bearing permanent magnet high-speed motor according to claim 1, characterized in that: A radial protection bearing is installed on the end cover side of the magnetic levitation bearing. The radial protection bearing is fitted with the rotating shaft, and there is a gap between the radial protection bearing and the rotating shaft for cooling air to flow.

3. A direct-drive steam compressor with a magnetic levitation bearing permanent magnet high-speed motor according to claim 2, characterized in that: A second air cavity is provided between the magnetic bearing 2 and the isolation seal. The second air cavity is used to introduce cooling gas and form a cooling branch. The magnetic levitation bearing 1, the stator, the thrust magnetic bearing, and the magnetic levitation bearing 2 are provided with flow channels that communicate with the cooling branch. The flow channels that communicate with the cooling branch are connected to the air outlet on the end cover. A gap that communicates with the cooling branch is provided between the radial protection bearing and the end cover.

4. A direct-drive steam compressor with a magnetic levitation bearing and permanent magnet high-speed motor according to claim 1, characterized in that: The cooling air is waterless compressed air.

5. A direct-drive steam compressor with a magnetic levitation bearing permanent magnet high-speed motor according to claim 1, characterized in that: The motor housing is provided with coolant channels, which are corresponding to the stator.

6. A direct-drive steam compressor with a magnetic levitation bearing permanent magnet high-speed motor according to claim 1, characterized in that: Both the isolation seal and the sealing seal adopt comb-tooth labyrinth seals.

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