Refrigeration equipment and control method and control device thereof

Abstract

The invention discloses refrigeration equipment and a control method and device thereof, the refrigeration equipment comprises a refrigeration system, the refrigeration system comprises a water vapor compressor, a condenser, a throttling device and an evaporator which are connected through a pipeline, the water vapor compressor comprises a main shaft and an air bearing arranged on the main shaft in a sleeving mode, and a motor cavity and a compression cavity which are separated from each other are formed in the water vapor compressor; the main shaft penetrates through the motor cavity and the compression cavity, the air bearing is located in the motor cavity, and the steam compressor is further provided with an air entraining opening communicated with the motor cavity. And the air entraining system comprises an air entraining flow path, and the air entraining flow path is communicated with the air entraining opening and is arranged to introduce air into the motor cavity so as to support the air bearing. According to the scheme, the compressor can adopt the high-speed air bearing to provide bearing for the rotor through the dynamic pressure or static pressure lubrication effect of air, high stability and low abrasion are achieved, the rotor supporting problem is solved for the compressor, the service life of the compressor is greatly prolonged, and the compressor is more compact. And meanwhile, the problems of working medium pollution and the like caused by using a traditional oil bearing or grease bearing are avoided.

Description

Technical Field

[0001] The present application relates to but is not limited to the technical field of refrigeration equipment, and specifically refers to a refrigeration equipment and a control method and a control device thereof. Background Art

[0002] Water (R718) is a pure natural substance that is ubiquitous in nature. It is green and environmentally friendly, easy to obtain raw materials, low cost, and safe. It is a perfect choice to replace conventional refrigerants. Refrigeration equipment (or water refrigeration system) that uses water as a refrigerant operates in a high vacuum environment, and the design of its compressor bearings is extremely challenging. At present, refrigeration equipment that uses conventional refrigerants for refrigeration uses oil-lubricated bearings for its compressors; refrigeration equipment that uses water for refrigeration can use high-speed grease-lubricated bearings when the compressor runs for a short time, and water-lubricated bearings can be used at low speeds. However, the above technical solutions all have great defects and it is difficult to meet the operating requirements of high-speed water vapor compressors.

[0003] Since water vapor compressors have the characteristics of large volume flow, high speed, and high vacuum environment, conventional oil-lubricated bearings have problems such as lubricating oil leakage, lubricating oil emulsification, and working fluid contamination, which may cause the system to fail to operate; grease-lubricated bearings can meet the compressor operation requirements in a relatively short period of time, but long-term operation will cause problems such as grease emulsification and bearing wear, making it difficult to meet product reliability requirements; water-lubricated bearings are suitable for low-speed conditions due to the low viscosity of water, and it is difficult to meet the requirements of high speed and small size. Summary of the invention

[0004] The technical problem to be solved by the present application is to provide a refrigeration equipment and its control method and control device. The compressor can use a high-speed air bearing to provide support for the rotor through the dynamic pressure or static pressure lubrication effect of the gas, which has high stability and low wear. It not only solves the rotor support problem for the compressor and greatly extends the service life of the compressor, but also avoids the problems such as working fluid pollution caused by the use of traditional oil bearings or grease bearings.

[0005] The technical solution for solving the above-mentioned technical problems in the embodiments of the present application is as follows: a refrigeration device, comprising: a refrigeration system, including a water vapor compressor, a condenser, a throttling device and an evaporator connected by pipelines, the water vapor compressor including a main shaft, an air floating bearing sleeved on the main shaft, a motor cavity and a compression cavity separated from each other are provided in the water vapor compressor, the main shaft is passed through the motor cavity and the compression cavity, the air floating bearing is located in the motor cavity, and the water vapor compressor is also provided with an air inlet connected to the motor cavity; and an air inlet system, including an air inlet flow path, the air inlet flow path is connected to the air inlet, and is configured to introduce gas into the motor cavity to support the air floating bearing.

[0006] The refrigeration equipment provided in the embodiment of the present application, the water vapor compressor, the condenser, the throttling device and the evaporator are connected by pipelines to form a refrigeration cycle. After the high-temperature and high-pressure water vapor discharged by the compressor enters the condenser to condense and release heat, it enters the evaporator after throttling and reducing the pressure by the throttling device, evaporates and absorbs heat in the evaporator, and then flows back to the compressor. The evaporator can be an indoor heat exchanger, which absorbs indoor heat by evaporation and cools the room. The condenser can be an outdoor heat exchanger, which releases heat to the outdoor environment by condensation.

[0007] The water vapor compressor includes a main shaft and an air bearing, and may also include components such as an impeller, a stator, a motor magnet, and an electronic stator. A motor cavity and a compression cavity are provided in the water vapor compressor, and the motor cavity and the compression cavity are separated from each other to avoid mutual influence. The motor cavity is mainly used to install relevant components of the motor, such as motor magnets, motor stators, main shafts, air bearings, etc. The compression cavity is mainly used to install components for compressing water vapor, such as impellers, etc. Therefore, the air bearing is located in the motor cavity, and the main body of the main shaft is located in the motor cavity. The output part of the main shaft is located in the compression cavity, which is used to connect with the impeller to drive the impeller to rotate. The output part of the main shaft can be thinner than the main body of the main shaft. The end of the impeller away from the motor cavity can be fixed to the output part of the main shaft by a locking nut to prevent axial movement.

[0008] The air inlet system includes an air inlet flow path, which can be connected to the air inlet of the water vapor compressor to introduce gas into the motor cavity of the water vapor compressor, so that the air bearing in the motor cavity can be supported by the gas, so that the bearing in the motor cavity forms an air bearing. The air bearing can meet the requirements of high speed and small size. The high-speed air bearing provides support for the rotor through the dynamic pressure or static pressure lubrication effect of the gas, and has the advantages of high stability and low wear. It not only solves the rotor support problem for the water vapor compressor, but also greatly extends the service life of the water vapor compressor. At the same time, it avoids the problems of working fluid pollution caused by the use of traditional oil bearings or grease bearings.

[0009] Based on the above technical solution, the present application can also be improved as follows.

[0010] In an exemplary embodiment, the air bleed path includes: an air bleed pipeline, the output end of which is connected to the air bleed port; an air pump, provided in the air bleed pipeline, configured to pressurize the gas input into the motor cavity; a first control valve, provided in the air bleed pipeline, configured to control the on-off and / or flow rate of the air bleed pipeline.

[0011] In an exemplary embodiment, the air induction system also includes: a pressure detection component, configured to detect the air pressure in the motor cavity; and a controller, electrically connected to the pressure detection component, the air pump and the first control valve, configured to control the air pump and the first control valve according to the detection result of the pressure detection component.

[0012] In an exemplary embodiment, the condenser is provided with a liquid outlet and an air outlet, the liquid outlet is configured to transport liquid refrigerant to the throttling device, the air inlet passage connects the air outlet and the air inlet, and is configured to introduce the gaseous refrigerant in the condenser into the motor cavity to support the air floating bearing; or, a gas-liquid separator is provided between the condenser and the throttling device, the gas-liquid separator is provided with an air outlet, the air inlet passage connects the air outlet and the air inlet of the gas-liquid separator, and is configured to introduce the gaseous refrigerant in the gas-liquid separator into the motor cavity to support the air floating bearing.

[0013] In an exemplary embodiment, the water vapor compressor is a multi-stage compressor, the number of the motor cavity is one, the number of the compression cavity is multiple, and the multiple compression cavities are distributed on both axial sides of the motor cavity.

[0014] In an exemplary embodiment, the air inlet is disposed at a position of the compression chamber close to a downstream side of the motor chamber.

[0015] In an exemplary embodiment, the water vapor compressor is further provided with a gas gap connecting the motor cavity and the compression cavity, and the gas gap is configured to allow the gaseous refrigerant in the motor cavity to enter the compression cavity.

[0016] In an exemplary embodiment, a sealing grate is provided between the motor cavity and the compression cavity, the sealing grate is sleeved on the main shaft and cooperates with the main shaft gap, and the air gap includes the gap between the sealing grate and the main shaft.

[0017] In an exemplary embodiment, the water vapor compressor also includes a casing and a motor casing, the casing is sealed and connected to the motor casing, the sealing grate is sleeved in the casing and abuts against the axial end of the motor casing; the casing and the sealing grate together enclose the compression chamber, and the motor casing and the sealing grate together enclose the motor chamber.

[0018] In an exemplary embodiment, the air bearing includes a first radial bearing, a second radial bearing and a thrust bearing, the first radial bearing and the second radial bearing are arranged axially spaced apart from each other along the main shaft, and the thrust bearing is arranged on a side of the first radial bearing away from the second radial bearing.

[0019] The present application also provides a control method for a refrigeration device as described in any one of the above embodiments, the control method comprising:

[0020] The air flow path is opened to introduce air into the motor cavity to support the air bearing.

[0021] In an exemplary embodiment, the control method further includes:

[0022] The water vapor compressor is started based on the air pressure in the motor cavity reaching a set pressure threshold range.

[0023] In an exemplary embodiment, the control method further includes:

[0024] After starting the water vapor compressor, the flow rate and / or the bleed air pressure of the bleed air flow path is adjusted according to the air pressure of the motor cavity, so that the air pressure of the motor cavity is maintained within the set pressure threshold range.

[0025] In an exemplary embodiment, the air flow path includes an air flow pipeline, an air pump and a first control valve; and opening the air flow path to introduce gas into the motor cavity to support the air bearing includes:

[0026] Starting the air pump and opening the first control valve to a set opening;

[0027] Based on the fact that the air pressure in the motor cavity does not reach a set pressure threshold range, the rotation speed of the air pump is increased.

[0028] An embodiment of the present application further provides a control device, including a processor and a memory storing a computer program, wherein the processor implements the steps of the control method described in any one of the above embodiments when executing the computer program. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the structure of a refrigeration device provided in some embodiments of the present application;

[0030] Figure 2 A schematic cross-sectional view of a water vapor compressor provided in some embodiments of the present application;

[0031] Figure 3 A flow chart of a control method provided in some embodiments of the present application;

[0032] Figure 4 A schematic diagram of the working principle of a refrigeration device provided in some embodiments of the present application.

[0033] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0034] 1 water vapor compressor, 11 primary compression unit, 12 secondary compression unit, 13 intermediate connecting pipe, 14 main shaft, 151 first radial bearing, 152 second radial bearing, 153 thrust bearing, 16 motor cavity, 161 air bleed port, 162 air bleed nozzle, 17 compression cavity, 171 primary compression cavity, 172 secondary compression cavity, 18 casing, 181 primary casing, 182 secondary casing, 19 motor casing, 102 sealing grate teeth, 1022 primary sealing grate teeth, 1024 secondary sealing grate teeth, 104 impeller, 1042 primary impeller, 1044 secondary impeller, 106 cooling water jacket, 108 water jacket cover plate, 110 locking nut, 1102 front locking nut, 1104 rear locking nut, 112 sealing ring, 114 motor stator, 116 motor magnet;

[0035] 2 condenser, 21 liquid outlet, 22 gas outlet, 3 throttling device, 4 evaporator;

[0036] 51 air bleed pipeline, 52 air pump, 53 first control valve;

[0037] 61 liquid pump, 62 second control valve, 63 cooling flow path;

[0038] 7. Liquid collector. DETAILED DESCRIPTION

[0039] The principles and features of the present application are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present application and are not used to limit the scope of the present application.

[0040] An embodiment of the present application provides a refrigeration device, including: a refrigeration system and an air bleed system.

[0041] like Figure 1 As shown, the refrigeration system includes a water vapor compressor 1, a condenser 2, a throttling device 3 and an evaporator 4 connected by pipelines. The throttling device 3 can be, but is not limited to, an expansion valve.

[0042] like Figure 2 As shown, the water vapor compressor 1 includes a main shaft 14 and an air bearing sleeved on the main shaft 14. A motor chamber 16 and a compression chamber 17 separated from each other are provided in the water vapor compressor 1. The main shaft 14 is inserted into the motor chamber 16 and the compression chamber 17. The air bearing is located in the motor chamber 16. The water vapor compressor 1 is also provided with an air inlet 161 connected to the motor chamber 16. An air inlet nozzle 162 can be provided at the air inlet 161 to facilitate docking with the air inlet flow path described below. The water vapor compressor 1 can be a centrifugal compressor.

[0043] The air bleed system includes an air bleed path. The air bleed path is connected to the air bleed port 161. Figure 1 and Figure 2 As shown, it is arranged to introduce gas into the motor cavity 16 to support the air bearing.

[0044] The refrigeration equipment provided in the embodiment of the present application, the water vapor compressor 1, the condenser 2, the throttling device 3 and the evaporator 4 are connected by pipelines to form a refrigeration cycle. After the high-temperature and high-pressure water vapor discharged by the compressor enters the condenser 2 for condensation and heat release, it enters the evaporator 4 after throttling and pressure reduction by the throttling device 3, evaporates and absorbs heat in the evaporator 4, and then flows back to the compressor. The evaporator 4 can be an indoor heat exchanger, which absorbs indoor heat by evaporation and cools the room. The condenser 2 can be an outdoor heat exchanger, which releases heat to the outdoor environment by condensation.

[0045] like Figure 2 As shown, the water vapor compressor 1 includes a main shaft 14 and an air bearing, and may also include an impeller 104, a stator, a motor magnet 116, an electronic stator and other components. A motor chamber 16 and a compression chamber 17 are provided in the water vapor compressor 1, and the motor chamber 16 and the compression chamber 17 are separated from each other to avoid mutual influence. The motor chamber 16 is mainly used to install relevant components of the motor, such as the motor magnet 116, the motor stator 114, the main shaft 14, the air bearing and the like. The compression chamber 17 is mainly used to install components for compressing water vapor, such as the impeller 104 and the like. Therefore, the air bearing is located in the motor chamber 16, and the main body of the main shaft 14 is located in the motor chamber 16. The output part of the main shaft 14 is located in the compression chamber 17, and is used to be connected to the impeller 104 to drive the impeller 104 to rotate. The output part of the main shaft 14 can be thinner than the main body of the main shaft 14. The end of the impeller 104 away from the motor chamber 16 can be fixed to the output part of the main shaft 14 by a locking nut 110 to prevent axial movement.

[0046] like Figure 1 As shown, the air induction system includes an air induction flow path, which can be connected to the air inlet 161 of the water vapor compressor 1 to introduce gas into the motor cavity 16 of the water vapor compressor 1, so that the air bearing in the motor cavity 16 can be supported by the gas, so that the bearing in the motor cavity 16 forms an air bearing. The air bearing can meet the requirements of high speed and small size. The high-speed air bearing provides support for the rotor through the dynamic pressure or static pressure lubrication effect of the gas, and has the advantages of high stability and low wear. It not only solves the rotor support problem for the water vapor compressor 1, but also greatly extends the service life of the water vapor compressor 1. At the same time, it avoids the problems of working fluid pollution caused by the use of traditional oil bearings or grease bearings.

[0047] In some exemplary embodiments, the condenser 2 is provided with a liquid outlet 21 and a gas outlet 22, such as Figure 1 The liquid outlet 21 is configured to deliver liquid refrigerant to the throttling device 3. The air inlet passage connects the air outlet 22 and the air inlet 161, and is configured to introduce the gaseous refrigerant in the condenser 2 into the motor cavity 16 to support the air bearing.

[0048] The high-temperature and high-pressure water vapor output by the water vapor compressor 1 is in the condenser 2, a part of which is condensed into liquid and deposited at the bottom of the condenser 2, and another part of which is maintained in gaseous state and gathered at the upper part of the condenser 2. Therefore, the liquid outlet 21 can be located at the bottom of the condenser 2, and is configured to transport liquid refrigerant to the throttling device 3. The air outlet 22 can be located at the upper part of the condenser 2, and is configured to transport water vapor to the motor cavity 16 of the water vapor compressor 1, so as to support the air bearing in the motor cavity 16 by using the water vapor.

[0049] In this way, the air bleed system does not need to be connected to other air sources, which is conducive to simplifying the structure of the refrigeration equipment and reducing production costs. In addition, the temperature of the gaseous refrigerant in the condenser 2 is relatively low, and it can also cool the motor magnet 116, the main shaft 14, the air bearing and other components in the motor cavity 16, which is conducive to improving the reliability of the water vapor compressor 1. In addition, the condensation pressure of the condenser 2 is relatively high (except for the highest pressure outside the water vapor compressor 1), so it is convenient to input a higher pressure gaseous refrigerant into the motor cavity 16 to meet the support requirements of the air bearing and reduce the requirements for the air pump 52.

[0050] Of course, the bleed air system can also be connected to other air sources.

[0051] In some embodiments, a liquid collector 7 may be further provided between the condenser 2 and the throttling device 3. Figure 1 As shown. The liquid collector 7 collects the liquid refrigerant discharged from the condenser 2 and delivers it to the throttling device 3. This ensures that the liquid refrigerant input to the throttling device 3 is liquid, which is conducive to stabilizing the pressure of the liquid refrigerant input to the throttling device 3 and reducing pressure fluctuations. In addition, a certain liquid level can be maintained in the liquid collector 7, which is convenient for using the liquid refrigerant in the liquid collector 7 to perform interstage cooling on the multi-stage water vapor compressor 1.

[0052] In other exemplary embodiments (not shown in the figure), a gas-liquid separator is provided between the condenser 2 and the throttling device 3. The gas-liquid separator is provided with an air outlet 22, and the air inlet 161 is connected to the air outlet 22 of the gas-liquid separator by an air inlet passage, and is configured to introduce the gaseous refrigerant in the gas-liquid separator into the motor cavity 16 to support the air bearing.

[0053] The refrigerant output from the condenser 2 to the gas-liquid separator will be separated into gas and liquid in the gas-liquid separator. The liquid refrigerant is deposited at the bottom of the gas-liquid separator and can be transported to the throttling device 3 through the liquid outlet 21 of the gas-liquid separator. The separated gaseous refrigerant is located at the upper part of the gas-liquid separator and can be transported to the motor cavity 16 of the water vapor compressor 1 through the air inlet path to support the air floating bearing.

[0054] In this way, the air bleed system does not need to be connected to other air sources, which is conducive to simplifying the structure of the refrigeration equipment and reducing production costs. In addition, the temperature of the gaseous refrigerant in the gas-liquid separator is relatively low, and it can also cool the motor magnetic steel 116, the main shaft 14, the air bearing and other components in the motor cavity 16, which is conducive to improving the reliability of the water vapor compressor 1. In addition, a certain liquid level can be maintained in the gas-liquid separator, which is convenient for using the liquid refrigerant in the gas-liquid separator to perform interstage cooling on the multi-stage water vapor compressor 1. Of course, the air bleed system can also be connected to other air sources.

[0055] In some exemplary embodiments, the air flow path includes: a pipeline, an air pump 52 and a first control valve 53, such as Figure 1 shown.

[0056] The output end of the air bleed line 51 is connected to the air bleed port 161. The air pump 52 is provided on the air bleed line 51, and is configured to pressurize the gas input into the motor cavity 16. The first control valve 53 is provided on the air bleed line 51, and is configured to control the on-off and / or flow rate of the air bleed line 51.

[0057] The air pump 52 as a power source can drive the gas to flow to the motor cavity 16 and pressurize the gas. In addition, the air pressure can be changed by changing the rotation speed of the air pump 52, so as to adjust the air pressure of the motor cavity 16.

[0058] The first control valve 53 can be used to control the on-off and flow rate of the bleed air pipeline 51. Of course, the first control valve 53 can also be used only to control the on-off of the bleed air pipeline 51, or only to control the flow rate of the bleed air pipeline 51. Other control valves can also be provided on the bleed air pipeline 51 to control the on-off or flow rate of the bleed air pipeline 51. The first control valve 53 can be, but is not limited to, a throttle valve.

[0059] In some exemplary embodiments, the bleed air system further includes: a pressure detection component (not shown in the figure) and a controller (not shown in the figure).

[0060] The pressure detection component is configured to detect the air pressure in the motor cavity 16 .

[0061] The controller is electrically connected to the pressure detection component, the air pump 52 and the first control valve 53, and is configured to control the air pump 52 and the first control valve 53 according to the detection result of the pressure detection component.

[0062] This facilitates automatic control of the air pressure in the motor cavity 16 , so that the air pressure in the motor cavity 16 can be maintained within a suitable air pressure range to ensure the normal and stable operation of the water vapor compressor 1 .

[0063] In some exemplary embodiments, the water vapor compressor 1 is a multi-stage compressor, such as Figure 1 and Figure 2As shown, there is one motor cavity 16, and there are multiple compression cavities 17, which are distributed on both axial sides of the motor cavity 16. One compression cavity 17 corresponds to one compression unit.

[0064] In this way, one main shaft 14 can drive multiple impellers 104 to rotate, which is conducive to simplifying the structure of the water vapor compressor 1, thereby helping to reduce the cost of the refrigeration equipment. In addition, only one motor cavity 16 needs to be induced, which is also conducive to simplifying the structure of the induced air system, thereby helping to reduce the cost of the refrigeration equipment.

[0065] Among them, a part of the compression chamber 17 is located on one axial side of the motor chamber 16, and another part of the compression chamber 17 is located on the other axial side of the motor chamber 16. The side where the first-stage compression chamber 17 is located is the upstream side of the motor chamber 16, and the side where the final-stage compression chamber 17 is located is the downstream side of the motor chamber 16. The number of compression chambers 17 on both sides of the motor chamber 16 can be equal or unequal. Adjacent compression chambers 17 can be connected through the gas collecting volute and the intermediate connecting pipe 13 to ensure that the gaseous refrigerant output from the previous stage compression chamber 171 can enter the adjacent next stage compression chamber 171.

[0066] In some exemplary embodiments, the air inlet 161 is disposed at a position of the motor cavity 16 close to the compression cavity 17 on the downstream side, such as Figure 2 The gaseous refrigerant can reach the area near the upstream side of the motor cavity 16 through the gap between the motor stator 114, the motor magnetic steel 116 and the main shaft 14, and then support the air bearing in this area.

[0067] As the gaseous refrigerant flows to the next-level compression chamber 171, the pressure and temperature of the gaseous refrigerant gradually increase, which will cause the pressure and temperature of the compression chamber 17 to gradually increase. Therefore, compared with the temperature of the area of ​​the motor chamber 16 close to the upstream compression chamber 17, the temperature of the area of ​​the motor chamber 16 close to the downstream compression chamber 17 is relatively high. Therefore, setting the air inlet 161 at a position close to the downstream compression chamber 17 of the motor chamber 16 is beneficial to use the gaseous refrigerant that has not yet been heated up by heat exchange to efficiently cool the area of ​​the motor chamber 16 close to the downstream compression chamber 17, which is beneficial to make the temperature and pressure in the motor chamber 16 tend to be uniform, thereby helping to improve the reliability of the water vapor compressor 1.

[0068] In some exemplary embodiments, the water vapor compressor 1 is further provided with a gas gap connecting the motor cavity 16 and the compression cavity 17 , and the gas gap is configured to allow the gaseous refrigerant in the motor cavity 16 to enter the compression cavity 17 .

[0069] In this way, the gaseous refrigerant in the motor cavity 16 can also flow into the compression cavity 17 through the air gap. Figure 2As shown, the water vapor in the compression chamber 17 is cooled to reduce the superheat of the water vapor output from the compression chamber 17, which is beneficial to reducing the heat load on the next-stage compression chamber 171, reducing thermal stress and thermal deformation, and is also beneficial to maintaining the water vapor output by the water vapor compressor 1 within a suitable superheat range, thereby helping to reduce the power consumption of the water vapor compressor 1 and improving system performance.

[0070] In addition, the flow area of ​​the air gap is relatively small, which can play a role in throttling and reducing the pressure of the gaseous refrigerant, which is beneficial to maintaining the air pressure in the motor cavity 16 at a higher pressure to meet the load-bearing requirements of the air bearing.

[0071] In some exemplary embodiments, a sealing grate 102 is provided between the motor chamber 16 and the compression chamber 17. Figure 2 As shown, the sealing grate teeth 102 are sleeved on the main shaft 14 and are in clearance with the main shaft 14, and the air gap includes the gap between the sealing grate teeth 102 and the main shaft 14. The air gap may also include the gap between the air bearing and the main shaft 14. In this way, the structure of the water vapor compressor 1 itself can be used to achieve the communication between the motor chamber 16 and the compression chamber 17.

[0072] In some exemplary embodiments, Figure 2 As shown, the water vapor compressor 1 also includes a casing 18 and a motor casing 19. The casing 18 is sealed and connected to the motor casing 19. The sealing grate teeth 102 are sleeved in the casing 18 and abut against the axial end of the motor casing 19. The casing 18 and the sealing grate teeth 102 enclose a compression chamber 17, and the motor casing 19 and the sealing grate teeth 102 enclose a motor chamber 16.

[0073] like Figure 2 As shown, the casing 18 and the motor casing 19 can be stoppered, and the sealing grate teeth 102 and the motor casing 19 can also be stoppered. In addition, the sealing grate teeth 102 are stoppered with the axial end of the motor casing 19 and the radial inner wall of the casing 18. The end of the sealing grate teeth 102 away from the motor cavity 16 is stoppered with the impeller 104, and the end of the sealing grate teeth 102 away from the motor cavity 16 is provided with a labyrinth-shaped gap channel.

[0074] Since the air pressure in the motor cavity 16 is greater than the air pressure in the compression cavity 17, the gaseous refrigerant in the motor cavity 16 can enter the compression cavity 17 through the gap between the air bearing and the main shaft 14 and the gap between the sealing grate teeth 102 and the main shaft 14, and then merge with the airflow in the compression cavity 17 (the airflow thrown out by the centrifugal force of the impeller 104) through the maze-shaped channel arranged on the end face of the sealing grate teeth 102.

[0075] A sealing ring 112 may be provided between the casing 18 and the motor housing 19 to achieve sealing and ensure that the motor cavity 16 is completely isolated from the outside.

[0076] In some exemplary embodiments, Figure 1 and Figure 2 As shown, the air bearing includes a first radial bearing 151, a second radial bearing 152 and a thrust bearing 153. The first radial bearing 151 and the second radial bearing 152 are arranged at intervals along the axial direction of the main shaft 14. The thrust bearing 153 is arranged on a side of the first radial bearing 151 away from the second radial bearing 152.

[0077] The thrust bearing 153 may be disposed in the area of ​​the motor chamber 16 close to the upstream compression chamber 17 , which is helpful in preventing the main shaft 14 from moving toward the upstream side.

[0078] In some embodiments, the water vapor compressor 1 is a two-stage compressor. Figure 2 As shown, there are two casings 18, which are a first-stage casing 181 and a second-stage casing 182. There are also two sealing grate teeth 102, which are a first-stage sealing grate teeth 1022 and a second-stage sealing grate teeth 1024. There are two impellers 104, which are a first-stage impeller 1042 and a second-stage impeller 1044. There are two locking nuts 110, which are a front locking nut 1102 and a rear locking nut 1104. The first-stage casing 181 and the first-stage sealing grate teeth 1022 enclose a first-stage compression chamber 171. The second-stage casing 182 and the second-stage sealing grate teeth 1024 enclose a second-stage compression chamber 172. The first-stage impeller 1042 is located in the first-stage compression chamber 171, and the second-stage impeller 1044 is located in the second-stage compression chamber 172. The thrust bearing 153 abuts against the first-level sealing grate teeth 1022 , and the second radial bearing 152 abuts against the second-level sealing grate teeth 1024 .

[0079] In some exemplary embodiments, the water vapor compressor 1 includes a plurality of compression modules connected in sequence, such as Figure 1 and Figure 2 Each compression module includes a compression unit, and the compression unit includes a compression chamber 17 , and adjacent compression chambers 17 are connected through an intermediate connecting pipe 13 .

[0080] The refrigeration device also includes a cooling system, and the cooling system includes a cooling flow path 63, such as Figure 1 The input end of the cooling flow path 63 is connected to the evaporator 4 and / or the condenser 2, and the output end of the cooling flow path 63 is connected to the intermediate connecting pipe 13, which is configured to transport the cooling medium in the evaporator 4 and / or the condenser 2 to the intermediate connecting pipe 13 to reduce the superheat of the refrigerant discharged from the intermediate connecting pipe 13.

[0081] Since the refrigerant temperature in the evaporator 4 and the refrigerant temperature in the condenser 2 are both lower than the refrigerant temperature in the compressor, the embodiment of the present application uses the cooling flow path 63 to transport the cooling medium in the evaporator 4 and / or the condenser 2 to the intermediate connecting pipe 13, and cools the refrigerant discharged from the adjacent compression unit on the upstream side of the intermediate connecting pipe 13. The temperature of the refrigerant discharged after cooling is reduced, thereby reducing the superheat of the refrigerant entering the next-stage compression unit 11, avoiding the refrigerant from being overheated and affecting the normal operation of the subsequent compression module and the refrigeration equipment. As a result, the refrigeration equipment can use the cooling medium in the system to cool the multi-stage compressor without the need for an external cooling source, which is conducive to reducing the volume of the refrigeration equipment and reducing the cost of the refrigeration equipment.

[0082] Among them, the input end of the cooling flow path 63 can be connected to the evaporator 4 and / or the condenser 2, and the cooling medium can be directly extracted from the evaporator 4 and / or the condenser 2. Since the evaporator 4 and the condenser 2 are large in volume and contain a large amount of cooling medium, the effect of extracting a certain amount of cooling medium on the pressure of the refrigeration system is relatively small. However, if the input end of the cooling flow path 63 is connected to the pipeline between the condenser 2 and the evaporator 4, the effect on the pressure of the refrigeration system is relatively large, so this solution is conducive to improving the reliability of the refrigeration equipment.

[0083] Alternatively, the input end of the cooling flow path 63 may also be connected to the flow path between the condenser 2 and the evaporator 4. For example, the input end of the cooling flow path 63 is connected to the liquid collector 7 (eg Figure 1 The cooling flow path 63 is also provided with a liquid pump 61 and a second control valve 62, as shown in FIG. Figure 1 As shown. In this way, the liquid pump 61 is used to pump cooling water for inter-stage cooling to the water vapor compressor 1. The second control valve 62 can be a throttle valve.

[0084] In some embodiments, the water vapor compressor 1 includes two compression modules, such as Figure 1 As shown, a spray device can be provided in the cooler to atomize and spray the cooling water into high-temperature and high-pressure water vapor, which is beneficial to increase the contact area and thus improve the cooling effect.

[0085] In some exemplary embodiments, the water vapor compressor 1 is further provided with a cooling water jacket 106, such as Figure 1 and Figure 2 As shown, the cooling water jacket 106 is sleeved on the outside of the motor stator 114. The cooling water jacket 106 is configured to circulate a cooling medium (such as cooling water) to cool the motor stator 114. The cooling water jacket 106 can be formed by a groove provided on the motor housing 19 and a water jacket cover plate 108.

[0086] The present application also provides a control method for a refrigeration device according to any one of the above embodiments. Figure 3 As shown, the control method includes:

[0087] Step S202: Open the air flow path to introduce air into the motor cavity to support the air bearing.

[0088] In this way, the air inlet 161 of the water vapor compressor 1 can be connected to the air inlet 161, and the gas can be introduced into the motor cavity 16 of the water vapor compressor 1, so that the air bearing in the motor cavity 16 can be supported by the gas, so that the bearing in the motor cavity 16 forms an air bearing. The air bearing can meet the requirements of high speed and small size. The high-speed air bearing provides bearing for the rotor through the dynamic pressure or static pressure lubrication effect of the gas, and has the advantages of high stability and low wear. It not only solves the rotor support problem for the water vapor compressor 1, but also greatly extends the service life of the water vapor compressor 1, while avoiding the problems of working fluid pollution caused by the use of traditional oil bearings or grease bearings.

[0089] In some exemplary embodiments, the control method further includes:

[0090] Based on the air pressure in the motor cavity 16 reaching the set pressure threshold range, the water vapor compressor 1 is started.

[0091] The set pressure threshold range may be: P ≥ set pressure value Pc.

[0092] This helps ensure that the water vapor compressor 1 can start and operate normally without causing failure or high wear during the startup process, which helps to extend the service life of the water vapor compressor 1.

[0093] In some exemplary embodiments, the control method further includes:

[0094] After the water vapor compressor 1 is started, the flow rate and / or the bleed air pressure of the bleed air path are adjusted according to the air pressure in the motor cavity 16 so that the air pressure in the motor cavity 16 is maintained within a set pressure threshold range.

[0095] This helps to ensure that the water vapor compressor 1 maintains stable and reliable operation for a long time during the refrigeration operation of the refrigeration equipment.

[0096] Among them, the air pressure in the motor cavity 16 can be maintained within the set pressure threshold range by only adjusting the flow rate of the air flow path (such as adjusting the opening of the first control valve 53), or the air pressure in the motor cavity 16 can be maintained within the set pressure threshold range by only adjusting the air pressure in the air flow path (such as adjusting the rotation speed of the air pump 52), or the air pressure in the motor cavity 16 can be maintained within the set pressure threshold range by adjusting the flow rate and the air pressure in the air flow path (such as adjusting the opening of the first control valve 53 and the rotation speed of the air pump 52).

[0097] In some exemplary embodiments, the bleed air flow path includes a bleed air pipeline 51 , an air pump 52 and a first control valve 53 .

[0098] The air flow path is opened to introduce air into the motor cavity 16 to support the air bearing, including:

[0099] Start the air pump 52 and open the first control valve 53 to a set opening;

[0100] Based on the fact that the air pressure in the motor cavity 16 does not reach the set pressure threshold range, the rotation speed of the air pump 52 is increased.

[0101] The set opening degree may be, but is not limited to, a maximum opening degree, such as 100%.

[0102] This helps the air pressure in the motor cavity 16 to quickly reach the set pressure threshold range, thereby helping to shorten the startup time of the refrigeration equipment and improving the user experience.

[0103] In the embodiment of the present application, the refrigeration device may be, but is not limited to, an air conditioner. The water vapor compressor 1 may be, but is not limited to, a multi-stage compressor. The multi-stage compressor may be a two-stage compressor or a compressor with more stages. The following takes the refrigeration device being an air conditioner and the compressor being a two-stage compressor as an example to explain the working principle of the refrigeration device.

[0104] like Figure 1 As shown, the air conditioner of this embodiment is a natural refrigerant water refrigeration air conditioning system. The refrigeration equipment mainly includes: a two-stage centrifugal compressor (including a primary compression unit 11 and a secondary compression unit 12), an evaporator 4, a condenser 2, a throttling device 3, a liquid pump 61, a liquid collector 7, an air pump 52, a first control valve 53, a second control valve 62, pipelines, etc. The primary compression unit 11 is a first-stage compression unit. The secondary compression unit 12 is a final-stage compression unit.

[0105] like Figure 1 and Figure 4As shown, the working principle of the refrigeration equipment is as follows: liquid refrigerant water evaporates in the evaporator 4, absorbs the heat of the room, and reduces the temperature of the room. The first-stage compression unit 11 inhales the water vapor evaporated in the evaporator 4, and the water vapor passes through the first-stage impeller 1042 to do work, the pressure and temperature increase, and further decelerates and increases the pressure in the diffuser, and flows into the inlet of the second-stage compression unit 12 through the gas collecting volute and the intermediate connecting pipe 13. Since the temperature of the water vapor is relatively high after compression, liquid water is introduced into the intermediate connecting pipe 13 for inter-stage cooling, and the water vapor with reduced superheat enters the second-stage compression unit 12 for further compression. The water vapor compressed from the centrifugal compressor flows into the condenser 2 for condensation, condenses into liquid water and supercooled water, and flows into the liquid collector 7 for collection. The water in the liquid collector 7 is divided into two parts, a small part is used for inter-stage cooling of the two-stage centrifugal compressor after being pressurized by the liquid pump 61, and most of it is reduced and throttled by the throttling device 3 to reduce the pressure to the saturation temperature corresponding to the evaporation temperature, and flows into the evaporator 4 for refrigeration.

[0106] The interstage cooling of the compressor can reduce the superheat of the gas entering the secondary compression unit 12, reduce the power consumption of the compressor, improve the system performance, and at the same time reduce the heat load of the secondary compression unit 12, reduce thermal stress and thermal deformation, and reduce the material selection and processing requirements for the centrifugal compressor. Interstage cooling measures the pressure and temperature of the gas before and after cooling, calculates the superheat, and the liquid pump 61 and the second control valve 62 are combined to adjust and control the superheat. The preset value range of the water vapor superheat can be 1°C to 5°C.

[0107] The water vapor compressor 1 in this embodiment is a two-stage high-speed centrifugal compressor. The two-stage impellers 104 are designed back-to-back, and the two impellers 104 are driven by a main shaft 14 to work. The high-speed motor is located in the center, and the two-stage compression units are located on both sides of the axial direction of the high-speed motor. The outlet of the first-stage compression unit 11 is connected to the inlet of the second-stage compression unit 12. The compressor rotor is supported by two radial bearings (i.e., the first radial bearing 151 and the second radial bearing 152) and a thrust bearing 153. An O-ring seal is used between the casing and the compressor casing 18 to ensure that the motor cavity 16 of the compressor is completely sealed from the outside. The motor cavity 16 is connected to the compressor main flow channel (i.e., the flow channel for the compressor to compress water vapor) through the bearing gap and the sealing grate 102. The introduced high-pressure gas flows into the motor cavity 16 and then flows into the compressor main flow channel after throttling through the rotor-static gap and the sealing grate 102. Due to the throttling effect of the small gap and the sealing grate 102, the motor cavity 16 can be maintained at a higher pressure to meet the bearing load requirements.

[0108] When the compressor is designed, its rotor system has a bearing capacity requirement, which is reflected in the bearing's requirement that its working environment, that is, the pressure in the motor cavity 16, is not lower than the critical working pressure Pc. Therefore, when starting to work, the air pump 52 is started, the first control valve 53 is opened to the default state (such as the maximum opening), and the pressurized gas enters the motor cavity 16 where the air bearing is located. The pressure sensor measures and feeds back the pressure parameter. If the measured pressure exceeds the critical pressure Pc, the compressor starts and drives the entire refrigeration system to work; if the measured pressure is lower than the critical pressure, the speed of the air pump 52 is increased, the air intake pressure is increased, until the pressure in the disc cavity reaches the critical pressure, and then the compressor is started, and the system starts to work. After the system starts to work, the air pressure in the motor cavity 16 can be adjusted by the air pump 52 and / or the first control valve 53 to maintain the air pressure in the motor cavity 16 within a range not lower than the critical working pressure Pc.

[0109] Table 1 is a comparison table of saturation temperature and saturation pressure when water evaporates. It can be seen from Table 1 that within the air-conditioning temperature range, the internal pressure of the refrigeration equipment is under extremely high vacuum conditions.

[0110] Table 1

[0111] Saturation temperature, °C 1.0 7.0 12.0 17.0 35.0 50.0 64.0 Saturation pressure, kPa 0.657 1.002 1.403 1.938 5.629 12.352 24.000

[0112] Table 2 is a relationship table between the air bearing capacity and the pressure of the motor chamber 16 calculated at the design speed of the compressor of an embodiment. It can be seen from Table 2 that when the pressure of the motor chamber 16 increases from 5.6 kPa (approximately the outlet pressure of the first-stage compression unit 11) to 24 kPa (approximately twice the condensing pressure), the air bearing capacity can be increased by more than 3 times.

[0113] Table 2

[0114] Disc cavity pressure, kPa 1.9 2.9 5.6 12 24 Bearing capacity, N 28.7 40.1 70.5 134.8 237.3

[0115] Therefore, the refrigeration device of this embodiment (structure as Figure 1 As shown, the working principle is as follows Figure 4 As shown in FIG. 1 , a water vapor compressor 1 and a control method using water (R718) as a refrigerant and a water vapor air bearing have the following advantages:

[0116] (1) Water (R718) is non-toxic, non-flammable, and non-explosive. It is ubiquitous in nature and is the most friendly to the ecological environment and human health. Moreover, when used as a refrigerant, the system operates in a vacuum state and is highly safe. ODP (ozone depletion potential) = 0, GWP (global warming potential) = 0.

[0117] (2) Using water vapor as the medium of the air bearing solves the problem of high-speed support of the compressor rotor, while avoiding problems such as working fluid pollution and high vacuum system leakage, which is beneficial to extending the service life of the compressor.

[0118] (3) The air bearing needs to meet certain pressure requirements to work. The water vapor refrigeration compressor works in a negative pressure environment. The system pressure cannot meet the bearing capacity requirements. Therefore, air is induced at the highest pressure position of the system, namely, condenser 2, and the induced air pressure is increased by an air pump 52 to meet the requirements of the rotor bearing capacity and axial force on the induced air pressure, thereby achieving stable operation of the compressor.

[0119] An embodiment of the present application also provides a control device, including a processor and a memory storing a computer program. When the processor executes the computer program, the steps of the control method in any of the above embodiments are implemented, and thus all the above-mentioned beneficial effects are achieved, which will not be repeated here.

[0120] The processor may be an integrated circuit chip with signal processing capabilities. The above-mentioned processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present invention may be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0121] An embodiment of the present application further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the steps of the control method as described in any one of the above embodiments are implemented, thereby having all the above-mentioned beneficial effects, which will not be repeated here.

[0122] To summarize, the refrigeration equipment and its control method and control device provided in the embodiments of the present application adopt an air bearing as the fulcrum of the compressor; the working medium of the air bearing is the refrigerant water vapor of the system; air is drawn in from the highest pressure position of the system, and is further pressurized by an air pump and introduced into the motor cavity where the bearing is located, so as to solve the problem of insufficient bearing capacity, and a pressure sensor, an air pump and a throttle valve are used in combination to control the flow rate and pressure of the induced air, so as to meet the requirements of the rotor bearing capacity and axial force of the compressor system, and ensure the smooth and safe operation of the compressor; at the same time, the induced air can also be used for balancing the axial force of the rotor in the compressor and dissipating heat, so as to further improve the reliability of the system.

[0123] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0124] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0125] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0126] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0127] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0128] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

[0129] In any one or more of the above exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or codes, and executed by a hardware-based processing unit. A computer-readable medium may include a computer-readable storage medium corresponding to a tangible medium such as a data storage medium, or a communication medium that facilitates the transmission of a computer program from one place to another, such as according to a communication protocol. In this way, a computer-readable medium may generally correspond to a non-temporary tangible computer-readable storage medium or a communication medium such as a signal or carrier wave. A data storage medium may be any available medium that can be accessed by one or more computers or one or more processors to retrieve instructions, codes, and / or data structures for implementing the technology described in the present disclosure. A computer program product may include a computer-readable medium.

[0130] By way of example and not limitation, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage, flash memory, or any other medium that can be used to store the desired program code in the form of instructions or data structures and can be accessed by a computer. Moreover, any connection may also be referred to as a computer-readable medium. For example, if instructions are transmitted from a website, server or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio and microwave are included in the definition of medium. However, it should be understood that computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other transient (transient) media, but are directed to non-transient tangible storage media. As used herein, disks and optical disks include compact disks (CDs), laser disks, optical disks, digital versatile disks (DVDs), floppy disks, or Blu-ray disks, etc., where disks typically reproduce data magnetically, while optical disks use lasers to reproduce data optically. Combinations of the above should also be included within the scope of computer-readable media.

[0131] For example, instructions may be executed by one or more processors such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuits. Thus, the term "processor" as used herein may refer to any of the above structures or any other structures suitable for implementing the techniques described herein. Additionally, in some aspects, the functionality described herein may be provided within dedicated hardware and / or software modules configured for encoding and decoding, or incorporated in a combined codec. Also, the techniques may be fully implemented in one or more circuits or logic elements.

[0132] The technical solutions of the embodiments of the present disclosure can be implemented in a wide variety of devices or equipment, including wireless mobile phones, integrated circuits (ICs) or a group of ICs (e.g., chipsets). Various components, modules or units are described in the embodiments of the present disclosure to emphasize the functional aspects of the devices configured to perform the described techniques, but they do not necessarily need to be implemented by different hardware units. Instead, as described above, the various units can be combined in a codec hardware unit or provided by a collection of interoperable hardware units (including one or more processors as described above) in combination with suitable software and / or firmware.

Claims

1. A refrigeration device, characterized in that: include: A refrigeration system, comprising a water vapor compressor, a condenser, a throttling device and an evaporator connected by pipelines, wherein the water vapor compressor comprises a main shaft and an air bearing sleeved on the main shaft, wherein a motor cavity and a compression cavity separated from each other are provided in the water vapor compressor, wherein the main shaft passes through the motor cavity and the compression cavity, wherein the air bearing is located in the motor cavity, and wherein the water vapor compressor is further provided with an air inlet communicated with the motor cavity; and The air bleed system comprises an air bleed flow path, wherein the air bleed flow path is connected to the air bleed port and is configured to introduce air into the motor cavity to support the air bearing.

2. The refrigeration equipment according to claim 1, characterized in that: The air flow path comprises: An air bleed pipeline, the output end of which is connected to the air bleed port; An air pump, disposed in the air duct, configured to pressurize the gas input into the motor cavity; The first control valve is arranged in the air bleed pipeline and is configured to control the on-off and / or flow rate of the air bleed pipeline.

3. The refrigeration equipment according to claim 2, characterized in that: The air bleed system also includes: a pressure detection component configured to detect the air pressure of the motor cavity; and The controller is electrically connected to the pressure detection component, the air pump and the first control valve, and is configured to control the air pump and the first control valve according to the detection result of the pressure detection component.

4. The refrigeration device according to any one of claims 1 to 3, characterized in that: The condenser is provided with a liquid outlet and an air outlet, the liquid outlet is configured to deliver liquid refrigerant to the throttling device, the air inlet passage connects the air outlet and the air inlet, and is configured to introduce the gaseous refrigerant in the condenser into the motor cavity to support the air bearing; or A gas-liquid separator is provided between the condenser and the throttling device. The gas-liquid separator is provided with an air outlet. The air inlet passage connects the air outlet of the gas-liquid separator and the air inlet, and is configured to introduce the gaseous refrigerant in the gas-liquid separator into the motor cavity to support the air floating bearing.

5. The refrigeration equipment according to any one of claims 1 to 3, characterized in that: The water vapor compressor is a multi-stage compressor, the number of the motor cavity is one, the number of the compression cavity is multiple, and the multiple compression cavities are distributed on both axial sides of the motor cavity.

6. The refrigeration device according to claim 5, characterized in that: The air inlet is arranged at a position of the compression chamber close to the downstream side of the motor chamber.

7. The refrigeration device according to any one of claims 1 to 3, characterized in that: The water vapor compressor is also provided with a gas gap connecting the motor cavity and the compression cavity, and the gas gap is configured to allow the gaseous refrigerant in the motor cavity to enter the compression cavity.

8. The refrigeration device according to claim 7, characterized in that: A sealing grate is provided between the motor cavity and the compression cavity. The sealing grate is sleeved on the main shaft and is clearance-matched with the main shaft. The air gap includes the gap between the sealing grate and the main shaft.

9. The refrigeration device according to claim 8, characterized in that: The water vapor compressor also includes a casing and a motor casing, the casing is sealed and connected to the motor casing, the sealing grate is sleeved in the casing and abuts against the axial end of the motor casing; the casing and the sealing grate together enclose the compression chamber, and the motor casing and the sealing grate together enclose the motor chamber.

10. The refrigeration equipment according to any one of claims 1 to 3, characterized in that: The air bearing comprises a first radial bearing, a second radial bearing and a thrust bearing. The first radial bearing and the second radial bearing are arranged at intervals along the axial direction of the main shaft. The thrust bearing is arranged on a side of the first radial bearing away from the second radial bearing.

11. A control method, characterized in that: For the refrigeration equipment according to any one of claims 1 to 10, the control method comprises: The air flow path is opened to introduce air into the motor cavity to support the air bearing.

12. The control method according to claim 11, characterized in that: Also includes: The water vapor compressor is started based on the air pressure in the motor cavity reaching a set pressure threshold range.

13. The control method according to claim 12, characterized in that: Also includes: After starting the water vapor compressor, the flow rate and / or the bleed air pressure of the bleed air flow path is adjusted according to the air pressure of the motor cavity, so that the air pressure of the motor cavity is maintained within the set pressure threshold range.

14. The control method according to any one of claims 11 to 13, characterized in that: The air bleed path includes an air bleed pipeline, an air pump and a first control valve; The step of opening the air flow path and introducing air into the motor cavity to support the air bearing comprises: Starting the air pump and opening the first control valve to a set opening; Based on the fact that the air pressure in the motor cavity does not reach a set pressure threshold range, the rotation speed of the air pump is increased.

15. A control device, characterized in that: The system comprises a processor and a memory storing a computer program, wherein when the processor executes the computer program, the steps of the control method according to any one of claims 11 to 14 are implemented.

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