Magnetic suspension compressor, dry grinding prevention method and system, cooling method and cooling method

Abstract

The invention relates to the field of data center refrigeration, in particular to a magnetic-air double-suspension centrifugal refrigeration compressor which comprises a motor shell, a first air-suspension bearing, a second air-suspension bearing, a first air-suspension bearing and a second air-suspension bearing. A stator core and a stator winding are also arranged in the motor shell; the stator winding comprises a first winding and a radial force winding; a first permanent magnet and a second permanent magnet are installed on the surface of the middle of the mandrel, a first impeller fixedly connected is installed at one end of the mandrel, and a second impeller fixedly connected is installed at the other end of the mandrel; the first volute shell is mounted on the outer part of the first impeller; and the second volute shell is mounted on the outer part of the second impeller. The core shaft is made to float through magnetism, unbalanced force is overcome through gaseous refrigerants and liquid refrigerants, and a new scheme is achieved.

Description

Technical Field

[0001] The present invention relates to the field of data center refrigeration, and specifically to a magnetic double-suspension centrifugal refrigeration compressor, a magnetic double-suspension centrifugal refrigeration compressor anti-dry wear method, a direct dual-phase change liquid cooling system, a server cooling method and a data center year-round natural cooling method. Background Art

[0002] The main components of the air conditioning system include the compressor, evaporator, expansion valve and condenser. The core of its working principle is the reverse Carnot cycle. The compressor compresses the refrigerant to turn it into a high-temperature and high-pressure gas, which is cooled down to a normal-temperature and high-pressure liquid through the condenser. The normal-temperature and high-pressure condensing agent in the evaporator absorbs a large amount of heat due to the pressure reduction, and the evaporator cools down. The fan blows out cold air from the evaporator to complete the refrigeration process.

[0003] Among the compressor styles, oil-free compressors have existed for a long time, but the dry wear of oil-free compressors is too serious, so mature oil-free compressors have only appeared in recent years. Oil-free compressors refer to compressors that do not use lubricating oil in the compressor cylinder. They are a special type of compressor that does not require any lubricating oil during the compression process. Since no lubricating oil comes into contact with the compressed gas source during operation, the discharged gas does not contain oil or gas, so it is very popular among users.

[0004] Oil-free compressors do not require lubricating oil, so they can provide higher efficiency; and oil-free compressors do not produce oil and gas pollution, so they have less impact on the environment; in addition, since there is no need to replace lubricating oil, the maintenance of oil-free compressors is relatively simple. For a variety of reasons, oil-free compressors have been used in air conditioners. In air conditioners, such compressors need to be able to work stably under various environmental conditions, including high temperature and high humidity environments; in addition, since air conditioning systems need to run continuously, such compressors usually need to have high durability and reliability.

[0005] The structure of the oil-free compressor mainly includes the motor, compressor body, bearings, sensors, controllers, etc. Oil-free compressors include two types: air suspension and magnetic suspension. Both types of compressors are single-stage centrifugal compressors. The core technology uses non-contact bearings, high-speed permanent magnet motors, and variable frequency speed regulation. Both can realize oil-free lubrication systems, with the characteristics of energy saving, high efficiency, low noise, and no oil pollution. However, their non-contact bearing types are different. Magnetic suspension compressors use magnetic suspension bearings, while air suspension compressors use air suspension bearings; both bearings can realize the floating rotor during operation, without mechanical contact and without lubrication. This design enables the oil-free compressor to operate without mechanical contact. In theory, it avoids the heat and wear generated by friction and improves the operating efficiency and service life of the equipment. However, there are still many problems with current oil-free compressors, at least as follows:

[0006] 1. The oil-free magnetic levitation compressor uses magnetic force to make the bearing float. The working principle of this compressor is: the inner surface of the stator is slotted and wound, the stator is made into an electromagnet, and the outer surface of the rotor is slotted and embedded with permanent magnets; when the rotor rotates, the magnetic repulsion between the stator and the rotor makes the rotor float. On the one hand, the magnetic force of magnetic levitation is small, and the exhaust of the compressor will cause an unbalanced force, causing it to swing back and forth. On the other hand, the equipment cost is high. The current equipment is used to detect the position and speed of the rotor through the surrounding probes (sensors); if the rotor is disturbed, the sensor transmits the detected signal to the controller, and the control signal will cause the power amplifier to generate a control current, and the control current will control the magnetic force, so that the rotor can be stably maintained in a balanced position and cannot swing back and forth; that is, based on position sensing, the magnitude of the magnetic force at different angles and different positions is controlled electrically to generate reverse thrust to reset the rotor; but the swing is in a constant state of change, so the precise control of magnetic levitation is a thorny problem, and the cost is very high and very complicated. Correspondingly, the risk of system failure and the difficulty of maintenance are increased. In addition, magnetic levitation compressors usually require reliable and stable power supply support to ensure the continued stability of their magnetic force, which places higher requirements on the system's energy management and operating environment.

[0007] Second, the gas suspension is not assisted by air, but by the high-pressure gaseous refrigerant from the compressor. However, if the compressor has not fully rotated and has not run for a period of time, there will be no high-pressure gaseous refrigerant, resulting in dry grinding between different parts for at least a period of time after the machine is started up, affecting the start-stop life and the number of times the bearing can be used. Dry grinding will not occur only if it does not rotate, but there will be no high-pressure gas if it does not rotate. The two are contradictory issues. Only after a period of dry grinding, when the gaseous refrigerant reaches the predetermined high pressure state, the internal rotating structure will float.

[0008] In addition, the working principle of air suspension involves two types of pressure, static pressure and dynamic pressure, one static pressure and one dynamic pressure (that is, dynamic and static); the dynamic pressure has no pressure and power when the machine is not turned on, so there will be dry grinding in the short time of starting and stopping. The start-up stage starts with slow dry grinding, and then the shaft slowly floats up. The static pressure is powered by another small fluorine pump, which first provides a high-pressure gas to the compressor to float the shaft first, and then start it after floating, thereby reducing dry grinding; but this fluorine pump cannot have oil, because if there is oil in the fluorine pump, oil will be mixed into the refrigerant, and the oil will block the small holes in the bearing, so the whole system cannot have oil, so the fluorine pump must also be oil-free, but if it is oil-free, the fluorine pump will dry grind when it starts, so this method reduces the dry grinding of the compressor, but transfers the dry grinding to the fluorine pump. Regarding this issue, it is only because the fluorine pump is cheap at present and the cost of replacing the fluorine pump afterwards is not high, so the industry has not paid too much attention to this issue. In addition, when the fluorine pump is started, some refrigerant needs to be extracted from the evaporator first, but the refrigerant in the evaporator is at a relatively low temperature, so it needs to be heated electrically before being supplied to the fluorine pump, which makes the entire startup time very long. Today, oil-free compressors are used in data centers, and data centers have requirements for startup time, which cannot be too long, because the heating speed of the data center is too fast, and if the time is too long, it cannot meet the use needs of the data center.

[0009] 3. Regardless of the type of compressor, high cost, low precision, dry grinding, and long start-up time are all existing problems. Regarding the problem of dry grinding, new technologies at home and abroad have been developed, and some wear-resistant materials have been used for remanufacturing, but in practice there is no better solution to the problem of dry grinding. In fact, it is only an improvement over the traditional one, but the overall effect is not obvious, and there is still the problem of short life.

[0010] 4. Currently, whether it is magnetic levitation or air levitation, once the shaft swings, it will have a great impact on the gap, and the swing amplitude cannot be controlled by a mechanical structure. Otherwise, as long as there is a mechanical structure, friction and dry grinding will occur. The current solution is only to correct the swing after it occurs, but does not solve the swing from the root.

[0011] 5. There is another new direction: data center. Data center, abbreviated as IDC, is Internet Data Center. In terms of function, a data center is an oversized computer room with many servers dedicated to centralized data management (storage, computing, and exchange). A data center is a facility designed specifically for storing, managing, and processing large-scale data. It usually consists of a large number of servers, network equipment, storage systems, and other necessary hardware and software. According to statistics from industry organizations, the global data traffic processed by data centers in 2020 reached 15.3ZB (1ZB≈1 billion TB), accounting for 99.35% of the global total traffic. In other words, almost all Internet data cannot be separated from the processing of data centers. The main function of data centers is to provide reliable computing and storage capabilities to meet the needs of individuals, organizations, and enterprises. They carry many important tasks, including hosting websites, applications, databases, cloud services, and big data analysis. In data centers, servers are core components that provide computing power and storage space. These servers are organized into clusters or collections for load balancing and high availability. Servers are connected through network devices to form a high-speed internal network for data transmission and communication. Data centers are usually monitored, operated, and managed by a dedicated technical team; they are responsible for ensuring the normal operation of servers and network equipment, diagnosing and repairing faults, and managing resource allocation and capacity planning. With the rapid development of cloud computing and big data, data centers are becoming increasingly important. Large Internet companies, financial institutions, telecommunications providers, and scientific research institutions all build and operate their own data centers to meet the growing computing and storage needs.

[0012] If the server in the data center does not have enough heat dissipation, the server will easily overheat in a high temperature environment, which will cause the performance of the processor and other hardware components to decline, thus affecting the normal operation speed and response time of the server; and overheated servers are prone to cause system crashes and shutdowns, as well as data loss and service interruptions... and other serious consequences, so the heat dissipation of the server in the data center is a very important and necessary condition. At present, the purpose of heat dissipation is achieved by blowing air conditioners into the data center; but a big cost is that the power consumption is very huge, so the air conditioning used in the data center, in order to save energy better, the only way is to pursue natural cooling, but the consensus of the air conditioning industry is that natural cooling can only be achieved in winter, and the location of the data center in the northern region of my country is more advantageous than the southern region, because the northern region is in low temperature weather for a longer time than the south in a year; but although the use of natural cooling can achieve the purpose of energy saving, there are still many serious problems, at least as follows:

[0013] At present, the design of natural cooling is prepared for winter. The way to cool the server is to blow air directly through the evaporator of the air conditioner, and use the cold air blown out to cool down. This efficiency is very low. Based on the original low efficiency problem, 3M Company of the United States has made new improvements. First, a large placement box is added to place the server in the placement box. Fluorine liquid is added to the placement box. A plate heat exchanger is set in the placement box, so that the air conditioner is connected with the plate heat exchanger for heat exchange to reduce the temperature of the fluorine liquid in the placement box and realize the cooling of the server. Compared with the traditional evaporator blowing, the efficiency of this solution is improved, but the efficiency of heat exchange is very poor. Specifically:

[0014] (1). The plate heat exchanger performs the first heat exchange with the air conditioner;

[0015] (2) The plate heat exchanger cools the fluorinated liquid in the storage box, and then cools the server a second time through the storage box;

[0016] (3) Low thermal conductivity, no significant improvement in efficiency;

[0017] (4) Many conversions in the middle also cause a lot of energy loss, and this is currently the ceiling of the industry's latest technology and a bottleneck that cannot be broken through;

[0018] (5) In addition, 3M's existing solution also has the problem of high equipment costs.

[0019] 6. The Chinese patent publication number is: CN110894854A, and the patent name is: A heavy-duty air-floating spindle with integrated permanent magnetic suspension. This prior art discloses a technical solution for air suspension of bearings; this prior art has small friction under ideal speed conditions, but large friction under high speed conditions. And this solution cannot be applied to air conditioners and cannot solve the corresponding technical problems, as follows:

[0020] 1. Different product applications have different requirements for friction and speed, and can withstand different unbalanced forces. Therefore, the above-mentioned prior art can float by adding air, but cannot solve the problems of high speed and swing; the prior art can only be applied to scenarios where the speed requirement is not high and the focus is on acceptable small friction; and the purpose of the prior art is to provide a technical solution for small friction; however, this small friction will still become large friction in the application scenario where the speed is too high.

[0021] 2. The above-mentioned prior art requires additional air to make the components float, and the entire process of use requires additional air and cannot be interrupted; air cannot be added in an air conditioner; what is more, the air contains water, and in a pressurized environment, the water in the air will precipitate, especially in a high-pressure environment, which will cause the water in the air to precipitate. The precipitated water will also cause corrosion and damage to bearings and related components; therefore, those skilled in the art know that this prior art is absolutely impossible to be applied to air conditioners, and water in air conditioners will damage refrigeration equipment.

[0022] 3. Therefore, the prior art can only have low rotation speed and small friction; the prior art is a technical solution to solve large friction and achieve small friction.

[0023] 4. In particular, changes in the cooling capacity of the air conditioner or changes in the weather will cause large changes and fluctuations in the middle. Therefore, this unbalanced force is also uneven and sometimes high and sometimes low. Therefore, if the existing technology is used, it will definitely be scrapped after one use or it will not start at the first start, and the entire bearing and related components will break.

[0024] 5. Permanent magnets, as well as permanent magnets or gas in existing technologies, all have a big problem, which is that the forces in different directions of front, back, left, and right cannot be controlled, and the reset function cannot be realized. Therefore, after starting, this unbalanced force will come out. For this problem, neither permanent magnets nor gas can solve it.

[0025] 6. In addition, the two ends of the existing compression inner rotor are the impellers of the centrifuge. The refrigerant enters at low pressure and comes out at high pressure. In the process of continuous discharge of unstable high-pressure refrigerant, the reaction force and unbalanced force of the high-pressure refrigerant discharge are very large; therefore, there is swing under high-speed rotation. For this problem, the existing technology cannot solve it whether it relies on permanent magnets or provides air solutions, and cannot solve this swing.

[0026] 7. The Chinese patent publication number is: CN105468117A, and the patent name is: Liquid cooling system for server. This prior art discloses a server cooling solution, but the solution cannot solve the same technical problem as the present invention.

[0027] In the research and development of existing technologies, a new type of immersion liquid is developed. The immersion liquid first exchanges heat with the refrigerant through a plate heat exchanger, and then cools the server immersed in the immersion liquid. This is an industry consensus because the refrigerant has always contained oil and the oil cannot enter the server.

[0028] In the prior art, those skilled in the art know that there have been oil-free compressors since the 19th century, and they also know that servers cannot have oil, as oil entering the server will cause damage to the server. Therefore, the compressors in the prior art obviously include conventional compressors and oil-free compressors. However, those skilled in the art know that oil entering the server will cause damage to the server. Therefore, the prior art solution places the server in the refrigerant, and the premise for cooling is that the server must be sealed, but the heat exchange is not good, and the efficiency of the heat exchange is not as good as directly immersing the server in the immersion liquid.

[0029] This is why in recent years, many leading companies in various countries around the world, including 3M in the United States, have spared no effort to develop new immersion fluids. This is because everyone has a misunderstanding that oil entering the server will cause damage to the server, so new immersion fluids are developed to improve heat exchange efficiency. All industry peers around the world have formed this cognitive bias and are vying to develop more advanced immersion fluids.

[0030] In addition, the above-mentioned prior art is incorrect in that it uses the first valve, the second valve and the pressure sensor. On the one hand, when the pressure is detected to be too high, the best time has been missed when the valve is opened; on the other hand, when the compressor is in operation, the closure of the valve will also cause damage due to the lack of refrigerant. However, if the compressor is also closed when the valve is closed, frequent start and stop will also cause damage to the compressor and condenser. At the same time, even if the switches of each component are relatively appropriate, the first valve and the second valve set in the prior art are too cumbersome. Summary of the invention

[0031] The purpose of the present invention is to solve at least some of the existing problems in the prior art and bring corresponding effective effects.

[0032] In order to solve the above technical problems, the magnetic double suspension centrifugal refrigeration compressor of the present invention comprises:

[0033] A motor housing, wherein a first air suspension bearing and a second air suspension bearing on the same axis are installed in the motor housing, wherein the first air suspension bearing and the second air suspension bearing are respectively located at two ends of the motor housing; wherein at least the first air suspension bearing is detachably connected to the motor housing;

[0034] The motor housing also has a stator core and a stator winding, and the stator core and the stator winding are coaxial with the first air suspension bearing; the stator winding includes a first winding and a radial force winding;

[0035] A core shaft, the diameter of which is smaller than the inner hole diameters of the first air suspension bearing and the second air suspension bearing, and the core shaft is located in the first air suspension bearing and the second air suspension bearing; a first permanent magnet and a second permanent magnet are installed on the middle surface of the core shaft, and the first permanent magnet and the second permanent magnet wrap the core shaft inside; a first impeller is fixedly installed at one end of the core shaft, and a second impeller is fixedly installed at the other end;

[0036] A first volute casing, the first volute casing being mounted outside the first impeller, the first volute casing being fixedly connected to the motor casing;

[0037] A second volute casing is installed outside the second impeller, and the second volute casing is fixedly connected to the motor casing.

[0038] As a preferred embodiment of the magnetic double-suspension centrifugal refrigeration compressor of the present invention, a first bearing seat is installed at one end of the motor housing, and a second bearing seat is installed at the other end; the first bearing seat, the second bearing seat and the first air suspension bearing are on the same axis; the first air suspension bearing is installed in the first bearing seat; the second air suspension bearing is installed in the second bearing seat.

[0039] As a preferred embodiment of the magnetic double-suspension centrifugal refrigeration compressor of the present invention, the two ends of the core shaft respectively have connecting shafts, and the first impeller and the second impeller are respectively installed on the connecting shafts at both ends of the core shaft; the connecting shafts at both ends of the core shaft are respectively threadedly connected with locking nuts.

[0040] As a preferred embodiment of the magnetic double-suspension centrifugal refrigeration compressor of the present invention, the middle part of the core shaft has an annular groove, and the first permanent magnet and the second permanent magnet are respectively installed in the annular groove; retaining rings are respectively installed on both sides of the first permanent magnet and the second permanent magnet, and the retaining rings are also in the annular groove.

[0041] As a preferred embodiment of the magnetic double-suspension centrifugal refrigeration compressor of the present invention, it includes a sheath, and the first permanent magnet and the second permanent magnet are installed in the sheath.

[0042] As a preferred embodiment of the magnetic double suspension centrifugal refrigeration compressor of the present invention, a positioning ring is installed at least at one end of the core shaft; a fixedly connected detection ring is installed in the inner hole of the first air suspension bearing; when the core shaft is in the first air suspension bearing, the position of the positioning ring corresponds to the detection ring;

[0043] It comprises a positioning and monitoring module, and the positioning and monitoring module is electrically connected to at least the detection ring and the positioning ring.

[0044] As a preferred embodiment of the magnetic double suspension centrifugal refrigeration compressor of the present invention, the core shaft is located at one end of the first air suspension bearing and has a thrust plate fixedly connected thereto;

[0045] The motor housing also has a thrust bearing on the same axis as the first air suspension bearing, and the thrust bearing is arranged parallel to the thrust plate; the core shaft passes through the thrust bearing at the same time; the first air suspension bearing is located between the thrust bearing and the second air suspension.

[0046] The magnetic double suspension centrifugal refrigeration compressor anti-dry wear method of the present invention comprises:

[0047] A magnetic double suspension centrifugal refrigeration compressor according to any one of the above,

[0048] During the startup phase, magnetism is used to keep the mandrel in a suspended state;

[0049] In the initial stage of startup, magnetism is used to suspend the core shaft, and low-pressure refrigerant is used to compensate for the slight unbalanced force during the rotation of the core shaft; as time goes by, the refrigerant gradually increases from low pressure to high pressure, and the speed of the core shaft is synchronously increased from low speed to high speed, and the refrigerant with real-time increased pressure is used to compensate for the unbalanced force of the core shaft with real-time increased speed;

[0050] During the operation stage, the shaft diameter of the core shaft and the first and second air suspension bearings, as well as the thrust plate and the thrust bearing are isolated by gaseous refrigerant and liquid refrigerant to form an air film and a liquid film. In the case of magnetic assisted suspension, the core shaft is suspended in both radial and axial directions by air and magnetic dual suspension, thus avoiding dry grinding and improving energy efficiency.

[0051] During the shutdown phase, the magnets and refrigerant are reused together to help slow down the spindle.

[0052] As a preferred implementation scheme of the magnetic double-suspension centrifugal refrigeration compressor anti-dry wear method of the present invention, when the refrigeration capacity changes or the weather changes causing the core shaft to have a large change in rotation speed during operation, the unbalanced force of the core shaft is compensated by high-pressure refrigerant, and gaseous refrigerant and liquid refrigerant are used to form gas film and liquid film for isolation, so as to prevent the core shaft from dry wear.

[0053] As a preferred implementation scheme of the magnetic-gas dual suspension centrifugal refrigeration compressor anti-dry wear method of the present invention, the high-speed operation of the core shaft in a region close to the surge zone is achieved by utilizing the magnetic and refrigerant gas-magnetic dual suspension and the isolation of the gas film and the liquid film.

[0054] The direct dual phase change liquid cooling system of the present invention adopts any one of the above-mentioned magnetic double suspension centrifugal refrigeration compressors and / or the above-mentioned magnetic double suspension centrifugal refrigeration compressor anti-dry wear method;

[0055] It also includes a condenser, an expansion valve and a sealing box;

[0056] The magnetic double suspension centrifugal refrigeration compressor includes a compressor inlet and a compressor outlet; the condenser includes a condenser inlet and a condenser outlet; the expansion valve includes an expansion valve inlet and an expansion valve outlet; the sealed box includes a sealed box inlet and a sealed box outlet;

[0057] The compressor outlet of the magnetic double suspension centrifugal refrigeration compressor is connected to the condenser inlet; the condenser outlet is connected to the expansion valve inlet; the expansion valve outlet is connected to the sealed box inlet; the sealed box outlet is connected to the compressor inlet; so that the magnetic double suspension centrifugal refrigeration compressor, the condenser, the expansion valve and the sealed box are connected in series to form a refrigeration cycle path;

[0058] The sealed box is located between the expansion valve and the magnetic double-suspension centrifugal refrigeration compressor; a server is arranged in the inner cavity of the sealed box;

[0059] The condenser receives the gaseous refrigerant from the compressor for heat exchange, converts the gaseous refrigerant into liquid refrigerant, completes the first phase change, and flows into the sealed box;

[0060] Among them, the sealed box receives the liquid refrigerant from the condenser, and makes the liquid refrigerant exchange heat with the server inside the sealed box, completes the second phase change, and flows into the compressor.

[0061] The server cooling method of the present invention adopts the above-mentioned direct dual phase change liquid cooling system;

[0062] Placing the server in a sealed box in the direct dual phase change liquid cooling system;

[0063] The server is cooled by directly contacting the refrigerant in the direct dual phase change liquid cooling system with the server;

[0064] The high temperature of the server is used to convert liquid refrigerant into gaseous refrigerant to achieve phase change.

[0065] The method for natural cooling of a data center all year round of the present invention comprises one of the following:

[0066] (1) The above-mentioned direct dual phase change liquid cooling system is used to achieve year-round natural cooling;

[0067] (2) Use the above server cooling method to achieve year-round natural cooling.

[0068] Beneficial Effects

[0069] The magnetic double-suspension centrifugal refrigeration compressor, the magnetic double-suspension centrifugal refrigeration compressor anti-dry wear method, the direct dual-phase change liquid cooling system, the server cooling method and the data center year-round natural cooling method of the present invention solve the above existing problems and other existing problems not mentioned above one by one and correspondingly bring at least the following innovative advantages:

[0070] 1. A compact and efficient motor structure is formed by the motor housing, stator core and stator winding. The core shaft, the first permanent magnet and the second permanent magnet are arranged in the internal space of the stator core to ensure the overall structural strength and operational stability. Among them, the first bearing seat and the second air suspension bearing both use dynamic pressure air suspension bearings, and both are radial bearings, which can effectively support the rotation of the core shaft, the first permanent magnet and the second permanent magnet; ensuring the operational stability of the compressor under high load conditions.

[0071] 2. The stator winding is arranged in the wire slots inside the stator core. The stator winding consists of two parts: the first winding and the radial force winding. The first winding is used to drive the axial rotation of the core shaft and the transmission of power torque; another part of the radial force winding 7 can generate a radial force that varies with the axial direction, further improving the control accuracy and response speed of the rotor.

[0072] 3. The first impeller and the second impeller are components that apply energy to the refrigerant and do work, and achieve effective compression of the refrigerant through centrifugal force; the first volute casing and the second volute casing are respectively installed at corresponding matching positions on the outside of the first impeller and the second impeller, thereby perfectly constructing the airflow path of the overall compressor and optimizing the airflow dynamics performance.

[0073] 4. In order to avoid contact between the core shaft and the first air suspension bearing and the second air suspension bearing during the start and stop of the compressor, and to avoid wear of the core shaft and the first air suspension bearing and the second air suspension bearing caused by the friction force on the contact surface when subjected to gravity, the first permanent magnet and the second permanent magnet, the stator core and the stator winding work together to achieve a magnetic suspension state during the start and stop stages, thereby effectively avoiding contact wear between the core shaft and the first air suspension bearing and the second air suspension bearing.

[0074] 5. In order to realize the positioning and control of magnetic suspension, a positioning ring is set at the position of the core shaft corresponding to the detection ring. The detection ring is used to monitor the position of the core shaft deviating from the axis in real time, so as to adjust the current size and direction of the radial force winding through the positioning and monitoring module, so as to maintain the stable suspension of the core shaft.

[0075] 6. To realize the magnetic suspension described in the present invention, the air suspension function is mainly realized by the first air suspension bearing, the second air suspension bearing, and the thrust bearing. When the operating speed of the compressor is higher than the normal operating speed of the conventional bearing, the gaseous refrigerant and the liquid refrigerant form an air film and a liquid film between the shaft diameter of the core shaft 8 and the first air suspension bearing 2 and the second air suspension bearing, and between the thrust plate and the thrust bearing for isolation, thereby realizing the gas-magnetic dual suspension of the core shaft in the radial direction and the axial direction, avoiding friction loss and improving energy efficiency. Since the present invention uses a mixture of magnetism and gas for the entire suspension; therefore, when the cooling capacity of the air conditioner fluctuates greatly, the unbalanced force is sometimes high and sometimes low, and when the speed is switched, it can also maintain stability.

[0076] 7. The present invention fully combines the advantages of air suspension and magnetic suspension. The difference from the traditional magnetic suspension compressor is that the magnetic suspension of the core shaft and the first and second permanent magnets is achieved through the first winding and radial force winding located in the stator core. As an auxiliary to the hydrodynamic air suspension bearing, the contact friction existing in the start-stop stage of the hydrodynamic air suspension bearing is completely avoided; at the same time, it does not need to adopt the complex structure of the traditional magnetic suspension bearing, that is, the spare bearing system; it further improves the reliability of the product and expands the application range of the product. In addition, the present invention does not require additional gas, and there is no situation of damaging the compressor; the gas mentioned in the present invention is not air, but refrigerant. The refrigerant plays the role of refrigeration on the one hand, and also plays the role of floating the bearing on the other hand. Especially when the core shaft is at a horizontal placement angle, its swing is more difficult to control. Therefore, through the magnetic suspension of the first winding and the radial force winding, and the first permanent magnet and the second permanent magnet, combined with the high-pressure refrigerant to fill the unbalanced force and reset the core shaft, as well as the gas film and liquid film formed by the gaseous refrigerant and the liquid refrigerant, the swing and dry grinding problems of the core shaft when it is placed horizontally can be solved; combined with the support of permanent magnets, the effect is greater than the existing gas suspension and magnetic suspension; and it can meet high speeds; it can achieve operation close to the surge zone.

[0077] 8. The present invention utilizes magnetism to make the core shaft float, and utilizes gaseous refrigerant and liquid refrigerant to overcome unbalanced forces, thus realizing a new solution.

[0078] 9. The present invention directly sets the server in a sealed box, so that the server is inside the direct dual-phase liquid cooling system and becomes a component in the direct dual-phase liquid cooling system, and the server completes the direct phase change inside the direct dual-phase liquid cooling system. This is the most direct and effective way; it achieves a great improvement in efficiency; it solves the current low efficiency problem of blowing cold air through the evaporator of the air conditioner, and solves the current problem of low thermal conductivity, low efficiency, large energy loss and high cost (equipment cost and electricity cost) caused by the secondary heat exchange between a plate heat exchanger and the server placement box for cooling. It also changes the cognitive bias that the leading companies in the industry are competing to develop more advanced immersion liquids.

[0079] 10. The consensus in the industry is that natural cooling can only be achieved in winter, and northern my country is more suitable for natural cooling because the temperature is low in winter and there are more low-temperature days in northern my country than in the south. Therefore, the present invention is not limited by location and time, and natural cooling can be achieved throughout the year or nearly throughout the year, breaking the inherent cognition of the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1 This is a rendering of Embodiment 1 of the present invention;

[0081] Figure 2 It is a cross-sectional effect diagram of the mandrel and related components of the present invention;

[0082] Figure 3 It is a cross-sectional effect diagram of the mandrel and related components of the present invention;

[0083] Figure 4 This is a flow chart of Embodiments 3 to 5 of the present invention.

[0084] In the figure: 1. motor housing, 2. first air suspension bearing, 3. second air suspension bearing, 4. stator core, 5. stator winding, 6. first winding, 7. radial force winding, 8. core shaft, 9. first permanent magnet, 10. second permanent magnet, 11. first impeller, 12. second impeller, 13. first volute housing, 14. second volute housing, 15. first bearing seat, 16. second bearing seat, 17. connecting shaft, 18. locking nut, 19. annular groove, 20. Retaining ring, 21. Protective sleeve, 22. Positioning ring, 23. Detection ring, 25. Thrust plate, 26. Thrust bearing, 27. Magnetic double suspension centrifugal refrigeration compressor, 28. Condenser, 29. Expansion valve, 30. Sealing box, 31. Compressor inlet, 32. Compressor outlet, 33. Condenser inlet, 34. Condenser outlet, 35. Expansion valve inlet, 36. Expansion valve outlet, 37. Sealing box inlet, 38. Sealing box outlet, 39. Server. DETAILED DESCRIPTION

[0085] In order to make the purpose, technical solution and advantages of the technical solution of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of specific embodiments of the present disclosure.

[0086] The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only part of the embodiments of the present disclosure, but not all of the embodiments.

[0087] Based on the described embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present disclosure.

[0088] In the field of air conditioning, there are two types of buoyancy required for the suspension of components: main buoyancy and unbalanced buoyancy. Therefore, the two problems must be solved at the same time (neither of them can be missing). One is to make the components float, and the other is to solve the swing and avoid dry grinding after floating.

[0089] The purpose of the present invention is to achieve zero friction, increase reliability and life. Because in the application of the present invention, the rotation speed may reach 80,000-90,000 revolutions per minute. Under the high-speed rotation of nearly 100,000 revolutions per minute, dry grinding is a serious problem that will be fatal. If the product of the prior art is used, one dry grinding may cause the equipment to be scrapped or even fail to start successfully for the first time.

[0090] Example 1

[0091] like Figures 1 to 3 As shown, the magnetic double suspension centrifugal refrigeration compressor of the present invention, see Figure 1 , comprising a motor housing 1, in which a first air suspension bearing 2 and a second air suspension bearing 3 on the same axis are installed, wherein the first air suspension bearing 2 and the second air suspension bearing 3 are respectively located at two ends of the motor housing 1; wherein at least the first air suspension bearing 2 is detachably connected to the motor housing 1;

[0092] The motor housing 1 also has a stator core 4 and a stator winding 5, and the stator core 4 and the stator winding 5 are coaxial with the first air bearing 2; the stator winding 5 includes a first winding 6 and a radial force winding 7;

[0093] A core shaft 8, the diameter of which is smaller than the inner hole diameter of the first air suspension bearing 2 and the second air suspension bearing 3, and the core shaft 8 is inside the first air suspension bearing 2 and the second air suspension bearing 3; the placement angle of the core shaft 8 is a vertical angle or a horizontal angle. A hollow structure is set inside the core shaft 8 corresponding to the position of the stator winding 5. The purpose of adopting the hollow structure is to further reduce the weight of the core shaft 8 and reduce the load; a first permanent magnet 9 and a second permanent magnet 10 are installed on the middle surface of the core shaft 8, and the first permanent magnet 9 and the second permanent magnet 10 wrap the core shaft 8 inside; a first impeller 11 is fixedly connected to one end of the core shaft 8, and a second impeller 12 is fixedly connected to the other end; Figure 2 It shows that the stator winding 5 is composed of the first permanent magnet 9 and the second permanent magnet 10 with a semicircular cross-section shape; the first permanent magnet 9 and the second permanent magnet 10 correspond to the N level and the S level of the magnetic pole respectively; that is, they are combined to form a pair of magnetic poles; driven by the electromagnetic force of the first winding 6, the rotation of the core shaft 8 is realized; under the action of the radial force winding 7, the first permanent magnet 9 and the second permanent magnet 10 are subjected to the radial force, so that the gravity load can be overcome and the magnetic suspension of the core shaft 8 can be realized;

[0094] A first volute casing 13, wherein the first volute casing 13 is installed outside the first impeller 11, and the first volute casing 13 is fixedly connected to the motor casing 1;

[0095] The second volute casing 14 is installed outside the second impeller 12 , and the second volute casing 14 is fixedly connected to the motor casing 1 .

[0096] The magnetic double suspension centrifugal refrigeration compressor of the present invention forms a compact and efficient motor structure through the motor housing 1, the stator core 4 and the stator winding 5. The core shaft 8, the first permanent magnet 9 and the second permanent magnet 10 are arranged in the internal space of the stator core 4 to ensure the overall structural strength and operating stability. Among them, the first bearing seat 15 and the second air suspension bearing 3 both adopt dynamic pressure air suspension bearings, and both belong to radial bearings, which can effectively support the rotation of the core shaft 8, the first permanent magnet 9 and the second permanent magnet 10; ensure the operating stability of the compressor under high load conditions.

[0097] In the present invention, a stator winding 5 is arranged in the wire slots inside the stator core 4. The stator winding 5 consists of two parts, a first winding 6 and a radial force winding 7. The first winding 6 is used to drive the axial rotation of the core shaft 8 and the transmission of power torque; another part of the radial force winding 7 can generate a radial force that varies with the axial direction, further improving the control accuracy and response speed of the rotor.

[0098] The first impeller 11 and the second impeller 12 are components that apply energy to the refrigerant and do work, and achieve effective compression of the refrigerant through centrifugal force; the first volute casing 13 and the second volute casing 14 are respectively installed at corresponding matching positions on the outside of the first impeller 11 and the second impeller 12, thereby perfectly constructing the airflow path of the overall compressor and optimizing the airflow dynamics performance.

[0099] In order to avoid contact between the core shaft 8 and the first air suspension bearing 2 and the second air suspension bearing 3 during the start and stop of the compressor, and to avoid the friction force on the contact surface causing wear of the core shaft 8 and the first air suspension bearing 2 and the second air suspension bearing 3 when the compressor is started and stopped, the first permanent magnet 9 and the second permanent magnet 10, the stator core 4 and the stator winding 5 work together to achieve a magnetic suspension state during the start and stop stages, thereby effectively avoiding contact wear between the core shaft 8 and the first air suspension bearing 2 and the second air suspension bearing 3.

[0100] Furthermore, a first bearing seat 15 is installed at one end of the motor housing 1, and a second bearing seat 16 is installed at the other end; the first bearing seat 15, the second bearing seat 16 and the first air suspension bearing 2 are on the same axis; the first air suspension bearing 2 is installed in the first bearing seat 15; and the second air suspension bearing 3 is installed in the second bearing seat 16.

[0101] For further information, see Figure 3 The two ends of the core shaft 8 are respectively provided with connecting shafts 17, and the first impeller 11 and the second impeller 12 are respectively installed on the connecting shafts 17 at both ends of the core shaft 8; the connecting shafts 17 at both ends of the core shaft 8 are respectively threadedly connected with locking nuts 18, that is, the first impeller 11 and the second impeller 12 are installed and disassembled through the locking nuts 18, which not only ensures the firmness of the impeller, but also facilitates subsequent maintenance and overhaul.

[0102] Furthermore, the middle of the core shaft 8 has an annular groove 19, and the first permanent magnet 9 and the second permanent magnet 10 are respectively installed in the annular groove 19; retaining rings 20 are respectively installed on both sides of the first permanent magnet 9 and the second permanent magnet 10, and the retaining rings 20 are also in the annular groove 19.

[0103] Further, comprising a sheath 21, Figure 2 and Figure 3It is shown that the first permanent magnet 9 and the second permanent magnet 10 are installed in the sleeve 21. The outer circumference of the first permanent magnet 9 and the second permanent magnet 10 is made of a non-magnetic material to form the sleeve 21, so as to realize the positioning and protection of the first permanent magnet 9 and the second permanent magnet 10. This design can effectively avoid the first permanent magnet 9 and the second permanent magnet 10 from falling off due to centrifugal force at high speed, and ensure the safety and stability of the compressor operation.

[0104] Furthermore, a positioning ring 22 is installed at least at one end of the core shaft 8; a fixedly connected detection ring 23 is installed in the inner hole of the first air suspension bearing 2; when the core shaft 8 is in the first air suspension bearing 2, the position of the positioning ring 22 corresponds to the detection ring 23;

[0105] It includes a positioning and monitoring module, and the positioning and monitoring module is electrically connected to at least the detection ring 23 and the positioning ring 22 .

[0106] In order to realize the positioning and control of magnetic suspension, a positioning ring 22 is set at the position of the core shaft 8 corresponding to the detection ring 23. In this example, the detection ring 23 is a position sensor, which is used to monitor the position of the core shaft 8 deviating from the axis in real time, so as to adjust the current size and direction of the radial force winding 7 through the positioning and monitoring module, so as to maintain the stable suspension of the core shaft 8.

[0107] Furthermore, the core shaft 8 is provided with a thrust plate 25 fixedly connected to one end of the first air bearing 2;

[0108] The motor housing 1 also has a thrust bearing 26 on the same axis as the first air suspension bearing 2. The thrust bearing 26 is arranged in parallel with the thrust plate 25. The mandrel 8 passes through the thrust bearing 26 at the same time. The first air suspension bearing 2 is between the thrust bearing 26 and the second air suspension. A thrust plate 25 and a corresponding thrust bearing 26 are arranged on the mandrel 8, and a hydrodynamic air suspension bearing is used to limit and stabilize the mandrel 8 in the axial direction. In the implementation of the present invention, the thrust bearing 26 also adopts a hydrodynamic air suspension bearing; the thrust plate 25 can be assembled as a separate disc, or it can be formed integrally with the mandrel 8.

[0109] In order to realize the magnetic suspension described in the present invention, the air suspension function is mainly realized by the first air suspension bearing 2, the second air suspension bearing 3, and the thrust bearing 26. When the operating speed of the compressor is higher than the normal operating speed of the conventional bearing, the gaseous refrigerant and the liquid refrigerant form an air film and a liquid film between the axial diameter of the core shaft 8 and the first air suspension bearing 2 and the second air suspension bearing 3, and between the thrust plate 25 and the thrust bearing 26 for isolation, thereby realizing the gas-magnetic dual suspension of the core shaft 8 in the radial direction and the axial direction, avoiding friction loss and improving energy efficiency. Since the present invention uses a mixture of magnetism and gas for the entire suspension; therefore, when the cooling capacity of the air conditioner fluctuates greatly, the unbalanced force is high and low, and when the speed is switched, it can also maintain stability.

[0110] The present invention fully combines the advantages of air suspension and magnetic suspension. The difference from the traditional magnetic suspension compressor is that the magnetic suspension of the core shaft 8 and the first permanent magnet 9 and the second permanent magnet 10 is realized by the first winding 6 and the radial force winding 7 located in the stator core 4. As an auxiliary to the dynamic pressure air suspension bearing, the contact friction existing in the start-stop stage of the dynamic pressure air suspension bearing is completely avoided; at the same time, it does not need to adopt the complex structure of the traditional magnetic suspension bearing, that is, the spare bearing system; further improves the reliability of the product and expands the application range of the product. In addition, the present invention does not require additional gas, and there is no situation of damaging the compressor; the gas mentioned in the present invention is not air, but refrigerant. The refrigerant plays the role of refrigeration on the one hand, and also plays the role of floating the bearing on the other hand. Especially when the core shaft 8 is at a horizontal placement angle, its swing is more difficult to control. Therefore, through the magnetic suspension of the first winding 6 and the radial force winding 7, and the first permanent magnet 9 and the second permanent magnet 10, and the high-pressure refrigerant to fill the unbalanced force and reset the core shaft 8, as well as the gas film and liquid film formed by the gaseous refrigerant and the liquid refrigerant, the swing and dry grinding problems of the core shaft 8 when it is placed horizontally can be solved; combined with the support of permanent magnets, the effect is greater than the existing gas suspension and magnetic suspension; and it can meet the high speed of 80,000-90,000 rpm; it can achieve operation close to the surge zone.

[0111] The scheme of the magnetic double suspension centrifugal refrigeration compressor of the present invention can be summarized as follows: during the startup phase, the core shaft 8 is placed in a suspended state by using magnetism;

[0112] In the initial stage of startup, the core shaft 8 is suspended by magnetism, and the low-pressure refrigerant is used to compensate for the slight unbalanced force during the rotation of the core shaft 8; as time goes by, the refrigerant gradually increases from low pressure to high pressure, and the speed of the core shaft 8 is synchronously increased from low speed to high speed, and the refrigerant with real-time increased pressure is used to compensate for the unbalanced force of the core shaft 8 with real-time increased speed;

[0113] During the operation stage, the shaft diameter of the core shaft 8 and the first air suspension bearing 2 and the second air suspension bearing 3, as well as the thrust plate 25 and the thrust bearing 26 are isolated by gaseous refrigerant and liquid refrigerant to form an air film and a liquid film. In the case of magnetic assisted suspension, the core shaft 8 is suspended in both radial and axial directions by air and magnetic dual suspension, thereby avoiding dry grinding and improving energy efficiency.

[0114] The magnetism and refrigerant used again during the shutdown phase together assist in slowing down the core shaft 8 .

[0115] Furthermore, when the cooling capacity changes or the weather changes, causing the rotation speed of the core shaft 8 to change significantly during operation, the high-pressure refrigerant is used to compensate for the unbalanced force of the core shaft 8, and the gaseous refrigerant and liquid refrigerant are used to form an air film and a liquid film for isolation, so as to prevent the core shaft 8 from dry grinding.

[0116] Furthermore, by utilizing the magnetic and refrigerant gas-magnetic dual suspension and the isolation of the gas film and the liquid film, the core shaft 8 can be operated at a high speed close to the surge zone. In the case of solving the dry grinding problem, the core shaft 8 can also be operated close to the surge zone.

[0117] Example 2

[0118] The present invention provides a method for preventing dry wear of a magnetic double-suspension centrifugal refrigeration compressor, which is based on the magnetic double-suspension centrifugal refrigeration compressor of Example 1 and specifically includes:

[0119] During the startup phase, magnetism is used to keep the mandrel 8 in a suspended state;

[0120] In the initial stage of startup, the core shaft 8 is suspended by magnetism, and the low-pressure refrigerant is used to compensate for the slight unbalanced force during the rotation of the core shaft 8; as time goes by, the refrigerant gradually increases from low pressure to high pressure, and the speed of the core shaft 8 is synchronously increased from low speed to high speed, and the refrigerant with real-time increased pressure is used to compensate for the unbalanced force of the core shaft 8 with real-time increased speed;

[0121] During the operation stage, the shaft diameter of the core shaft 8 and the first air suspension bearing 2 and the second air suspension bearing 3, as well as the thrust plate 25 and the thrust bearing 26 are isolated by gaseous refrigerant and liquid refrigerant to form an air film and a liquid film. In the case of magnetic assisted suspension, the core shaft 8 is suspended in both radial and axial directions by air and magnetic dual suspension, thereby avoiding dry grinding and improving energy efficiency.

[0122] The magnetism and refrigerant used again during the shutdown phase together assist in slowing down the core shaft 8 .

[0123] Furthermore, when the cooling capacity changes or the weather changes, causing the rotation speed of the core shaft 8 to change significantly during operation, the high-pressure refrigerant is used to compensate for the unbalanced force of the core shaft 8, and the gaseous refrigerant and liquid refrigerant are used to form an air film and a liquid film for isolation, so as to prevent the core shaft 8 from dry grinding.

[0124] Furthermore, by utilizing the magnetic and refrigerant gas-magnetic dual suspension, as well as the isolation of the gas film and the liquid film, the high-speed operation of the core shaft 8 in a region close to the surge zone is achieved. Compressor surge refers to the phenomenon of low-frequency (usually only a few hertz or more than ten hertz) and high-amplitude (strong pressure and flow fluctuations) airflow oscillation along the axis of the compressor. This low-frequency and high-amplitude airflow oscillation is a great source of exciting force, which can cause strong mechanical vibration of the compressor components and overheating of the hot end. It can also cause serious damage to the components in a very short time, so the compressor is not allowed to enter the surge zone under any conditions, otherwise the equipment will be scrapped. The present invention provides a solution for magnetic and gas dual suspension, which can solve the problem of dry grinding and can also operate close to the surge zone.

[0125] When the magnetic double-suspension centrifugal refrigeration compressor and the compressor manufactured by the magnetic double-suspension centrifugal refrigeration compressor anti-dry grinding method of the present invention are applied to the refrigeration system, the time of starting and stopping the system is saved first, and it can be started and stopped quickly to meet the needs of the data center. It solves the problem that the current dynamic pressure air suspension will cause dry grinding, and also solves the problem that the current static pressure air suspension will cause dry grinding of the fluorine pump. The service life of the system is increased. In addition, it also solves the problem of the high cost of the current magnetic suspension oil-free compressor.

[0126] Example 3

[0127] The direct dual phase change liquid cooling system of the present invention, see Figure 4 , including all the contents of the magnetic double suspension centrifugal refrigeration compressor of Example 1 and / or the anti-dry wear method of the magnetic double suspension centrifugal refrigeration compressor of Example 2; therefore, the same as Example 1 will not be repeated, the difference is that,

[0128] It also includes a condenser 28, an expansion valve 29 and a sealing box 30;

[0129] The magnetic double suspension centrifugal refrigeration compressor includes a compressor inlet 31 and a compressor outlet 32; the condenser 28 includes a condenser inlet 33 and a condenser outlet 34; the expansion valve 29 includes an expansion valve inlet 35 and an expansion valve outlet 36; the sealed box 30 includes a sealed box inlet 37 and a sealed box outlet 38;

[0130] The compressor outlet 32 ​​of the magnetic double suspension centrifugal refrigeration compressor is connected to the condenser inlet 33; the condenser outlet 34 is connected to the expansion valve inlet 35; the expansion valve outlet 36 is connected to the sealed box inlet 37; the sealed box outlet 38 is connected to the compressor inlet 31; so that the magnetic double suspension centrifugal refrigeration compressor, the condenser 28, the expansion valve 29 and the sealed box 30 are connected in series to form a refrigeration cycle path;

[0131] The sealed box 30 is located between the expansion valve 29 and the magnetic double suspension centrifugal refrigeration compressor 27; a server 39 is arranged in the inner cavity of the sealed box 30;

[0132] The condenser 28 receives the gaseous refrigerant from the compressor for heat exchange, converts the gaseous refrigerant into liquid refrigerant, completes the first phase change, and flows into the sealed box 30;

[0133] The sealed box 30 receives the liquid refrigerant from the condenser 28, and makes the liquid refrigerant exchange heat with the server 39 inside the sealed box 30, completes the second phase change, and flows into the compressor.

[0134] The present invention directly sets the server in the sealed box 30, so that the server 39 is inside the direct dual-phase liquid cooling system and becomes a component in the direct dual-phase liquid cooling system, and the server 39 completes the direct phase change inside the direct dual-phase liquid cooling system, which is the most direct and effective; it achieves a great improvement in efficiency; it solves the current low efficiency problem of blowing cold air through the evaporator of the air conditioner, and solves the current problem of low thermal conductivity, low efficiency, large energy loss and high cost (equipment cost and electricity cost) caused by the secondary heat exchange between a plate heat exchanger and the server placement box for cooling. It also changes the cognitive bias that the leading companies in the industry are competing to develop more advanced immersion liquids.

[0135] Example 4

[0136] The server cooling method of the present invention adopts the direct dual phase change liquid cooling system of embodiment 3;

[0137] The server 39 is placed in the sealed box 30 in the direct dual phase change liquid cooling system; the server 39 is directly immersed in the refrigerant of the sealed box without any seal;

[0138] The server 39 is cooled by directly contacting the refrigerant in the direct dual phase change liquid cooling system with the server 39;

[0139] The high temperature of the server 39 is used to convert the liquid refrigerant into a gaseous refrigerant to achieve phase change.

[0140] Example 5

[0141] 13. The data center's year-round natural cooling method includes one of the following:

[0142] (1) Using the direct dual phase change liquid cooling system of Example 3 to achieve year-round natural cooling;

[0143] (2) Use the server cooling method of Example 4 to achieve year-round natural cooling.

[0144] The consensus in the industry is that natural cooling can only be achieved in winter, and northern my country is more suitable for natural cooling because the temperature is low in winter and there are more low temperature days in northern my country than in the south. Therefore, the present invention is not limited by location and time, and natural cooling can be achieved throughout the year or nearly throughout the year, breaking the inherent cognition of the industry.

[0145] The words "first", "second" and similar words used in the specification and claims do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "an" or "the" do not indicate a quantitative limitation, but rather indicate the presence of at least one. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprises" include the elements or objects listed after "include" or "comprises" and their equivalents, and do not exclude other elements or objects. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0146] The preferred embodiments of the present invention described above are only the preferred embodiments of the present invention and are not intended to limit the present invention. The protection scope of the present invention is defined by the attached claims. For ordinary technicians in this field, other embodiments can be obtained according to the drawings without creative work, and any changes based on the claims of the present invention are within the protection scope of the present invention.

Claims

1. Magnetic double suspension centrifugal refrigeration compressor, It is characterized in that include: A motor housing, in which a first air suspension bearing and a second air suspension bearing on the same axis are installed, wherein the first air suspension bearing and the second air suspension bearing are respectively located at two ends of the motor housing; wherein at least the first air suspension bearing is detachably connected to the motor housing; The motor housing also has a stator core and a stator winding, and the stator core and the stator winding are coaxial with the first air suspension bearing; the stator winding includes a first winding and a radial force winding; A core shaft, the diameter of which is smaller than the inner hole diameters of the first air suspension bearing and the second air suspension bearing, and the core shaft is located in the first air suspension bearing and the second air suspension bearing; a first permanent magnet and a second permanent magnet are installed on the middle surface of the core shaft, and the first permanent magnet and the second permanent magnet wrap the core shaft inside; a first impeller is fixedly installed at one end of the core shaft, and a second impeller is fixedly installed at the other end; A first volute casing, the first volute casing being mounted outside the first impeller, the first volute casing being fixedly connected to the motor casing; A second volute casing is installed outside the second impeller, and the second volute casing is fixedly connected to the motor casing.

2. The magnetic double suspension centrifugal refrigeration compressor according to claim 1, It is characterized in that A first bearing seat is installed at one end of the motor housing, and a second bearing seat is installed at the other end; the first bearing seat, the second bearing seat and the first air suspension bearing are on the same axis; the first air suspension bearing is installed in the first bearing seat; the second air suspension bearing is installed in the second bearing seat.

3. The magnetic double suspension centrifugal refrigeration compressor according to claim 1, It is characterized in that The two ends of the core shaft are respectively provided with connecting shafts, and the first impeller and the second impeller are respectively installed on the connecting shafts at the two ends of the core shaft; the connecting shafts at the two ends of the core shaft are respectively threadedly connected with locking nuts.

4. The magnetic double suspension centrifugal refrigeration compressor according to claim 1, It is characterized in that The core shaft has an annular groove in the middle, and the first permanent magnet and the second permanent magnet are respectively installed in the annular groove; retaining rings are respectively installed on both sides of the first permanent magnet and the second permanent magnet, and the retaining rings are simultaneously located in the annular groove.

5. The magnetic double suspension centrifugal refrigeration compressor according to claim 4, It is characterized in that A sheath is included, in which the first permanent magnet and the second permanent magnet are installed.

6. Anti-dry wear method for magnetic double suspension centrifugal refrigeration compressor, It is characterized in that include: A magnetic double suspension centrifugal refrigeration compressor according to any one of claims 1 to 5, During the startup phase, magnetism is used to keep the mandrel in a suspended state; In the initial stage of startup, magnetism is used to suspend the core shaft, and low-pressure refrigerant is used to compensate for the slight unbalanced force during the rotation of the core shaft; as time goes by, the refrigerant gradually increases from low pressure to high pressure, and the speed of the core shaft is synchronously increased from low speed to high speed, and the refrigerant with real-time increased pressure is used to compensate for the unbalanced force of the core shaft with real-time increased speed; During the operation stage, the shaft diameter of the core shaft and the first and second air suspension bearings, as well as the thrust plate and the thrust bearing are isolated by gaseous refrigerant and liquid refrigerant to form an air film and a liquid film. In the case of magnetic assisted suspension, the core shaft is suspended in both radial and axial directions by air and magnetic dual suspension, thus avoiding dry grinding and improving energy efficiency. During the shutdown phase, the magnets and refrigerant are reused together to help slow down the spindle.

7. The method for preventing dry wear of a magnetic double-suspension centrifugal refrigeration compressor according to claim 6, It is characterized in that By utilizing the magnetic and refrigerant gas-magnetic dual suspension and the isolation of the air film and liquid film, the high-speed operation of the core shaft close to the surge zone is achieved.

8. Direct dual phase change liquid cooling system, It is characterized in that A method for preventing dry wear of a magnetic double-suspension centrifugal refrigeration compressor according to any one of claims 1 to 5 and / or a method for preventing dry wear of a magnetic double-suspension centrifugal refrigeration compressor according to claim 6; It also includes a condenser, an expansion valve and a sealing box; The magnetic double suspension centrifugal refrigeration compressor includes a compressor inlet and a compressor outlet; the condenser includes a condenser inlet and a condenser outlet; the expansion valve includes an expansion valve inlet and an expansion valve outlet; the sealed box includes a sealed box inlet and a sealed box outlet; The compressor outlet of the magnetic double suspension centrifugal refrigeration compressor is connected to the condenser inlet; the condenser outlet is connected to the expansion valve inlet; the expansion valve outlet is connected to the sealed box inlet; the sealed box outlet is connected to the compressor inlet; so that the magnetic double suspension centrifugal refrigeration compressor, the condenser, the expansion valve and the sealed box are connected in series to form a refrigeration cycle path; The sealed box is located between the expansion valve and the magnetic double-suspension centrifugal refrigeration compressor; a server is arranged in the inner cavity of the sealed box; The condenser receives the gaseous refrigerant from the compressor for heat exchange, converts the gaseous refrigerant into liquid refrigerant, completes the first phase change, and flows into the sealed box; Among them, the sealed box receives the liquid refrigerant from the condenser, and makes the liquid refrigerant exchange heat with the server inside the sealed box, completes the second phase change, and flows into the compressor.

9. Server cooling method, It is characterized in that A direct dual phase change liquid cooling system according to claim 8; Placing the server in a sealed box in the direct dual phase change liquid cooling system; The server is cooled by directly contacting the refrigerant in the direct dual phase change liquid cooling system with the server; The high temperature of the server is used to convert liquid refrigerant into gaseous refrigerant to achieve phase change.

10. Data center year-round natural cooling method, It is characterized in that The method comprises one of the following: (1) using the direct dual phase change liquid cooling system of claim 8 to achieve year-round natural cooling; (2) using the server cooling method of claim 9 to achieve year-round natural cooling.

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