Gas supply system for gas bearings of compressors, method of operation and refrigeration system

Abstract

The application relates to a gas supply system of a gas bearing of a compressor, an operating method and a refrigeration system. The gas supply system of the gas bearing of the compressor comprises the following: a first compressor and a refrigeration circulation path where the first compressor is located, a gas bearing arranged in the first compressor, a gas supply tank, a gas inlet pipe connecting the gas supply tank and a first part of the refrigeration circulation path, a gas outlet pipe connecting the gas supply tank and the first compressor, a gas return pipe connecting the gas supply tank and a second part of the refrigeration circulation path, and an adjusting valve arranged in the gas return pipe, the opening degree of the adjusting valve being adjustable to adjust the gas flow in the gas return pipe; wherein in the normal stable working state of the first compressor, the gas pressure at the first part is greater than the gas pressure at the second part. The application adjusts the gas pressure in the gas supply tank through the adjusting valve on the gas return pipe to provide the gas bearing with stable pressure gas refrigerant, and the structure is simple, the operation control is convenient, and the reliability is high.

Description

Technical Field

[0001] This invention relates to the field of refrigeration systems, and more particularly to a gas supply system, operating method, and refrigeration system for a gas bearing used in a compressor. Background Technology

[0002] Centrifugal chillers are commonly used in various building air conditioning systems. Currently, the compressor bearings of centrifugal chillers generally use oil-lubricated bearings and electromagnetic bearings (i.e., magnetic levitation bearings).

[0003] Using oil-lubricated bearings requires an additional lubrication supply system, increasing system complexity. During compressor operation, lubricating oil can leak into the refrigeration system and mix with the refrigerant; therefore, a lubricating oil return system is needed for periodic oil return. Oil-lubricated bearings also present problems such as mechanical friction, reduced mechanical efficiency, and decreased unit performance.

[0004] Centrifugal compressors using electromagnetic bearings rely on magnetic force to levitate the bearings. The electrical control system of magnetic levitation bearings is complex and bulky, has high requirements for bearing machining consistency, and has poor system shock resistance. In addition, it requires additional abnormal power failure protection measures.

[0005] Currently, gas bearings (air suspension bearings) are beginning to be used in centrifugal compressors. Gas bearings use gas force to support the rotating shaft and have the following advantages: 1) Compared with compressors using oil-lubricated bearings, there is no need for an oil supply system, oil return system, oil cooling system, or filtration system, eliminating the risk of lubricating oil leakage and saving on lubricating oil maintenance; when the bearing is working, it is in a suspended state with no friction, reducing mechanical losses and improving unit performance; 2) Compared with compressors using magnetic suspension bearings, there is no need for a complex electrical control system and an abnormal power failure protection system.

[0006] However, since gas bearings require external gas supply during operation, there is a problem of unstable gas supply to gas bearings. Summary of the Invention

[0007] Some embodiments of the present invention provide a gas supply system, operating method and refrigeration system for a gas bearing for a compressor, to alleviate the problem of unstable gas supply.

[0008] Some embodiments of the present invention provide a gas supply system for a gas bearing of a compressor, comprising:

[0009] The first compressor and its refrigeration cycle path, wherein the gas bearing is located in the first compressor;

[0010] Gas supply tank;

[0011] An intake pipe connects the gas supply tank to a first part of the refrigeration cycle path, and the intake pipe is configured to direct the gaseous refrigerant in the refrigeration cycle path to the gas supply tank.

[0012] An outlet pipe connects the gas supply tank to the first compressor, and the outlet pipe is configured to direct the gaseous refrigerant in the gas supply tank to the gas bearing to supply gas to the gas bearing;

[0013] A return pipe, connecting the gas supply tank to a second portion of the refrigeration cycle path, is configured to direct gaseous refrigerant from the gas supply tank to the refrigeration cycle path; and

[0014] A regulating valve is provided in the return gas pipe, and the opening of the regulating valve is adjustable to regulate the gas flow rate in the return gas pipe;

[0015] Under normal and stable operating conditions of the first compressor, the gas pressure at the first part is greater than the gas pressure at the second part.

[0016] In some embodiments, the gas supply system for the gas bearing of the compressor includes a second compressor, the intake pipe includes a first pipe, the second compressor is disposed on the first pipe, and the exhaust end of the second compressor is connected to the gas supply tank. The second compressor is configured to pressurize the gaseous refrigerant in the first pipe and send it to the gas supply tank.

[0017] In some embodiments, the gas supply system for the compressor gas bearing includes a first direction control element disposed on the first pipe and located between the exhaust end of the second compressor and the gas supply tank. The first direction control element is configured to control the flow of gaseous refrigerant from the second compressor to the gas supply tank.

[0018] In some embodiments, the gas supply system for the compressor gas bearing includes a second direction control element, the intake pipe includes a second pipe connected in parallel with the first pipe, the second direction control element is disposed on the second pipe, and the second direction control element is configured to control the flow of gaseous refrigerant from a first part of the refrigeration cycle path to the gas supply tank.

[0019] In some embodiments, the second compressor is configured to start before the first compressor starts, in a newly started state, or in an unstable operating state, so as to pressurize the gaseous refrigerant in the first pipe and send it to the gas supply tank.

[0020] In some embodiments, the gas supply system for the compressor gas bearing includes a condenser located in the refrigeration cycle path, and the first portion includes a portion on the condenser.

[0021] In some embodiments, the gas supply system for the compressor gas bearing includes an evaporator disposed in the refrigeration cycle path, and the second portion includes a portion on the evaporator.

[0022] In some embodiments, the gas supply system for the compressor gas bearing includes a flash evaporator disposed in the refrigeration cycle path, and the second portion includes a portion on the flash evaporator.

[0023] In some embodiments, the gas supply system for the gas bearing of the compressor includes a first pressure sensor and a second pressure sensor. The first pressure sensor is disposed in the first compressor and configured to detect the internal pressure of the first compressor. The second pressure sensor is disposed in the gas supply tank and configured to detect the gas pressure in the gas supply tank.

[0024] In some embodiments, the gas supply system for the compressor gas bearing includes a third pressure sensor located in the condenser and configured to detect the internal pressure of the condenser.

[0025] Some embodiments of the present invention provide a refrigeration system that includes the gas supply system for the gas bearing of the compressor described above.

[0026] Some embodiments of the present invention provide an operating method for a gas supply system for a compressor gas bearing, comprising:

[0027] Set the differential pressure value P X =P1-P2; where P1 is the gas pressure in the gas supply tank; P2 is the internal pressure of the first compressor;

[0028] When P X <P T Reduce the opening of the regulating valve;

[0029] When P X >P T Increase the opening of the regulating valve;

[0030] When P X =P T To maintain the opening of the regulating valve unchanged;

[0031] Among them, P T The target gas pressure value required for the gas bearing of the first compressor to operate normally and stably.

[0032] In some embodiments, the gas supply system for the gas bearing of the compressor includes a second compressor, and the intake pipe includes a first pipe and a second pipe connected in parallel, with the second compressor disposed on the first pipe;

[0033] In P3-P2 <P min At that time, the second compressor starts, and according to P X With P T Adjust the opening degree of regulating valve 61 according to the relationship;

[0034] In P3-P2≥P min At that time, the second compressor shuts down, and according to P X With P T Adjust the opening of the regulating valve according to the relationship;

[0035] Where P3 is the gas pressure at the first location; P min The minimum gas pressure required for the gas bearing of the first compressor to operate normally and stably is P. min ≤P T .

[0036] In some embodiments, when the first compressor is in a newly started state, or the first compressor is off, or the first compressor is in an unstable operating state, P3-P2 <P min ;

[0037] When the first compressor is in a stable operating state, P3 - P2 ≥ P min .

[0038] Based on the above technical solution, the present invention has at least the following beneficial effects:

[0039] In some embodiments, the inlet pipe leads the gaseous refrigerant in the refrigeration cycle path to the gas supply tank, and the outlet pipe leads the gaseous refrigerant in the gas supply tank to the gas bearing to supply gas to the gas bearing; the return pipe leads the gaseous refrigerant in the gas supply tank back to the refrigeration cycle path, and the gas pressure in the gas supply tank is regulated by the regulating valve on the return pipe to provide the gas bearing with a stable pressure of gaseous refrigerant. The structure is simple and the operation and control are convenient. Compared with the coordinated operation of multiple valves, the single valve control has higher reliability. Moreover, the excess gaseous refrigerant in the gas supply tank returns to the first compressor and its refrigeration cycle path through the return pipe, which can improve the performance of the first compressor. Attached Figure Description

[0040] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0041] Figure 1 This is a schematic diagram of a refrigeration system provided according to some embodiments of the present invention.

[0042] Figure 2 This is a schematic diagram of a refrigeration system provided according to other embodiments of the present invention. Detailed Implementation

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0044] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0045] Gas bearings utilize gas force to support the rotating shaft. To ensure the normal and stable operation of the gas bearing, a stable and reliable gas supply system is required. Once the gas pressure provided by the supply system meets the requirements for the normal and stable operation of the gas bearing, the compressor shaft can be suspended, and the compressor motor can rotate. A stable and sufficient gas supply pressure to the gas bearing is a prerequisite for the normal and stable operation of the compressor.

[0046] like Figure 1 As shown, some embodiments provide a gas supply system for a gas bearing of a compressor, which includes: a first compressor 1 and the refrigeration cycle path therein, a gas supply tank 3, an inlet pipe 4, an outlet pipe 5, a return pipe 6, and a regulating valve 61.

[0047] A gas bearing is located in the first compressor 1 and is used to support the rotating shaft inside the first compressor 1. The gas supply tank 3 is configured to supply gas to the gas bearing inside the first compressor 1 so that the gas bearing can operate normally and stably.

[0048] The intake pipe 4 connects the gas supply tank 3 to the first part of the refrigeration cycle path. The intake pipe 4 is configured to guide the gaseous refrigerant in the refrigeration cycle path to the gas supply tank 3.

[0049] The outlet pipe 5 connects the gas supply tank 3 and the first compressor 1. The outlet pipe 5 is configured to lead the gaseous refrigerant in the gas supply tank 3 to the gas bearing to supply gas to the gas bearing.

[0050] The return pipe 6 connects the gas supply tank 3 to the second part of the refrigeration cycle path. The return pipe 6 is configured to guide the gaseous refrigerant in the gas supply tank 3 to the refrigeration cycle path.

[0051] A regulating valve 61 is located in the return gas pipe 6. The opening of the regulating valve 61 is adjustable to regulate the gas flow rate in the return gas pipe 6. Optionally, the opening of the regulating valve 61 can be adjusted between 0% and 100%.

[0052] Under normal and stable operating conditions, the gas pressure at the first part of the first compressor 1 is greater than the gas pressure at the second part.

[0053] In some embodiments, the intake pipe 4 leads the gaseous refrigerant in the refrigeration cycle path to the gas supply tank 3, the outlet pipe 5 leads the gaseous refrigerant in the gas supply tank 3 to the gas bearing to supply gas to the gas bearing, and the return pipe 6 leads the gaseous refrigerant in the gas supply tank 3 back to the refrigeration cycle path, and the return pipe 6 is equipped with an adjustable regulating valve 61. In the above process, if the pressure of the gaseous refrigerant provided by the gas supply tank 3 is greater than the gas pressure required for the normal and stable operation of the gas bearing, the pressure of the gaseous refrigerant provided by the gas supply tank 3 is reduced by adjusting the opening of the regulating valve 61; if the pressure of the gaseous refrigerant provided by the gas supply tank 3 is less than the gas pressure required for the normal and stable operation of the gas bearing, the pressure of the gaseous refrigerant provided by the gas supply tank 3 is increased by adjusting the opening of the regulating valve 61; if the pressure of the gaseous refrigerant provided by the gas supply tank 3 is equal to the gas pressure required for the normal and stable operation of the gas bearing, the opening of the regulating valve 61 remains unchanged. In other words, the gas pressure in the gas supply tank 3 can be adjusted by the regulating valve 61 on the return gas pipe 6 to provide a stable pressure of gaseous refrigerant to the gas bearing. The structure is simple and the operation and control are convenient. Compared with the coordinated operation of multiple valves, the single valve control is more reliable. Moreover, the excess gaseous refrigerant in the gas supply tank 3 returns to the first compressor 1 and its refrigeration cycle path through the return gas pipe 6, which can improve the performance of the first compressor 1.

[0054] In some embodiments, the gas supply system for the gas bearing of the compressor includes a second compressor 2, an intake pipe 4 includes a first pipe 41, the second compressor 2 is disposed in the first pipe 41, and the exhaust end of the second compressor 2 is connected to the gas supply tank 3. The second compressor 2 is configured to pressurize the gaseous refrigerant in the first pipe 41 and send it to the gas supply tank 3.

[0055] If the gas pressure in the refrigeration cycle path of the first compressor 1 does not reach the gas pressure required by the gas bearing, the second compressor 2 pressurizes the gaseous refrigerant in the refrigeration cycle path of the first compressor 1 to meet the gas pressure required for the operation of the gas bearing, thus solving the problem that there is not enough pressure difference in the unit to supply gas to the gas bearing.

[0056] By pressurizing the gaseous refrigerant in the refrigeration cycle path of the first compressor 1 through the second compressor 2, a continuous and stable gas pressure can be provided to the gas bearing, which is conducive to ensuring the continuous and stable operation of the gas bearing; and the gaseous refrigerant supplied to the gas bearing is relatively pure and is not easily mixed with liquid refrigerant, which is conducive to ensuring the reliability of the gas bearing.

[0057] The gaseous refrigerant in the refrigeration cycle path of the first compressor 1 is pressurized by the second compressor 2 and supplied to the gas bearing. This process does not involve liquid media and does not require throttling devices, gas-liquid separation devices, etc., making it simple in structure and easy to operate.

[0058] In some embodiments, the gas supply system for the compressor gas bearing includes a first direction control element 411. The first direction control element 411 is disposed on a first pipe 41 and located between the exhaust end of the second compressor 2 and the gas supply tank 3. The first direction control element 411 is configured to control the flow of gaseous refrigerant from the second compressor 2 to the gas supply tank 3. By providing the first direction control element 411, backflow of gaseous refrigerant in the gas supply tank 3 to the second compressor 2 is prevented.

[0059] Optionally, the first direction control element 411 includes a directional control valve such as a check valve or a solenoid valve.

[0060] In some embodiments, the gas supply system for the compressor gas bearing includes a second direction control element 421. The intake pipe 4 includes a second pipe 42 connected in parallel with the first pipe 41. The second direction control element 421 is disposed on the second pipe 42 and configured to control the flow of gaseous refrigerant from a first part of the refrigeration cycle path to the gas supply tank 3. By providing the second direction control element 421, backflow of gaseous refrigerant in the gas supply tank 3 into the refrigeration cycle path where the first compressor 1 is located is prevented.

[0061] Optionally, the second direction control element 421 includes a directional control valve such as a check valve or a solenoid valve.

[0062] In some embodiments, the second compressor 2 is configured to start before the first compressor 1 starts, in the initial start-up state, or in an unstable operating state, so as to pressurize the gaseous refrigerant in the first pipe 41 and send it to the gas supply tank 3.

[0063] Before the first compressor 1 is started, the pressure of the gaseous refrigerant in the refrigeration cycle path of the first compressor 1 is low and cannot reach the working pressure required by the gas bearing. The second compressor 2 pressurizes the gaseous refrigerant in the refrigeration cycle path of the first compressor 1 and supplies it to the gas bearing, which can solve the problem that there is not enough pressure difference in the unit to supply gas to the gas bearing before the unit is started.

[0064] When the first compressor 1 is just started, the pressure of the gaseous refrigerant in the refrigeration cycle path of the first compressor 1 gradually increases, but it still does not reach the working pressure required by the gas bearing. The second compressor 2 pressurizes the gaseous refrigerant in the refrigeration cycle path of the first compressor 1 and supplies it to the gas bearing, which can solve the problem that there is not enough pressure difference in the unit to supply gas to the gas bearing.

[0065] When the first compressor 1 is in an unstable operating state, the pressure of the gaseous refrigerant in the refrigeration cycle path of the first compressor 1 may be unstable, and there may be a situation where the working pressure required by the gas bearing cannot be met. By using the second compressor 2 to pressurize the gaseous refrigerant in the refrigeration cycle path of the first compressor 1 and supply it to the gas bearing, a continuous and stable pressure gas can be provided to the gas bearing.

[0066] In some embodiments, the intake pipe 4 includes a first pipe 41 and a second pipe 42 connected in parallel. The second compressor 2 is located on the first pipe 41. The second compressor 2 can selectively operate to supply refrigerant to the gas supply tank 3. The second pipe 42 is always connected to the refrigeration cycle path where the first compressor 1 is located and the gas supply tank 3. That is to say, by adopting the control method of selective gas supply by the second compressor 2 combined with a stable flow path, problems such as frequent start-up and shutdown of the gas supply system and liquid carryover in the gas supply are avoided, and the gas supply is stable, which effectively improves the reliability of the gas supply system and the unit operation.

[0067] In some embodiments, the gas supply system for the compressor gas bearing includes a condenser 7, which is located in the refrigeration cycle path. The first part includes a portion on the condenser 7. Of course, the first part is not limited to a portion on the condenser 7, but may also include the exhaust port of the first compressor 1, or the pipeline between the first compressor 1 and the condenser 7, etc. In other words, any component or part in the refrigeration cycle path where the first compressor 1 is located that contains gaseous refrigerant can be used as the first part.

[0068] The first pipe 41 and the second pipe 42 connect to the space inside the condenser 7 where the gaseous refrigerant is located.

[0069] In some embodiments, the gas supply system for the compressor gas bearing includes an evaporator 8, which is located in the refrigeration cycle path, and the second part includes a portion on the evaporator 8.

[0070] In some embodiments, the gas supply system for the compressor gas bearing includes a flash 10 disposed in the refrigeration cycle path, and the second portion includes a portion on the flash 10.

[0071] The return pipe 6 connects to the space containing the gaseous refrigerant in the evaporator 8 or flash evaporator 10.

[0072] Of course, the second part is not limited to the part on the evaporator 8 or the flash evaporator 10. It can also include the air inlet of the first compressor 1, or the pipeline between the first compressor 1 and the evaporator 8, etc. In other words, any part on the refrigeration cycle path where the first compressor 1 is located can be included, as long as the gas pressure at the first part is greater than the gas pressure at the second part under the normal and stable working condition of the first compressor 1.

[0073] In some embodiments, the gas supply system for the compressor gas bearing includes a first pressure sensor 11 and a second pressure sensor 31. The first pressure sensor 11 is disposed in the first compressor 1 and configured to detect the internal pressure of the first compressor 1. The second pressure sensor 31 is disposed in the gas supply tank 3 and configured to detect the gas pressure inside the gas supply tank 3.

[0074] The internal pressure of the first compressor 1 is the pressure that limits the normal and stable operation of the gas bearing. The gas pressure provided by the gas supply tank 3 needs to overcome the internal pressure of the first compressor 1, the weight of the compressor shaft, and the radial force experienced by the shaft during rotation in order to enable the gas bearing to operate normally and stably. When the gas bearing is operating normally and stably, the compressor shaft becomes suspended, and the compressor operates normally and stably.

[0075] In some embodiments, the gas supply system for the compressor gas bearing includes a third pressure sensor 71 disposed in the condenser 7, the condenser 7 being configured to detect the internal pressure of the condenser 7.

[0076] In some embodiments, the first compressor 1 includes a centrifugal compressor.

[0077] In some embodiments, the second compressor 2 includes a compressor with a small volumetric flow rate, such as a scroll compressor, a shaft compressor, or a piston compressor.

[0078] In some embodiments, the volumetric flow rate of the first compressor 1 is greater than the volumetric flow rate of the second compressor 2.

[0079] In some embodiments, a first filter 412 is provided on the first pipe 41. A second filter 422 is provided on the second pipe 42. A third filter 51 is provided on the exhaust pipe 5.

[0080] In some embodiments, no regulating valves are required on the first pipe 41, the second pipe 42, and the outlet pipe 5. Only a regulating valve 61 is required on the return pipe 6 to regulate the pressure inside the gas supply tank 3, providing a stable pressure of gaseous refrigerant for the gas bearing. This method has a simple structure, is easy to operate and control, and has high reliability.

[0081] Some embodiments provide a refrigeration system that includes the gas supply system for the gas bearing of the compressor described above.

[0082] The refrigeration system includes a gas supply system for a gas bearing for a compressor, which includes a first compressor 1 and a refrigeration cycle path in which the first compressor 1 is located.

[0083] In some embodiments, such as Figure 1 As shown, the refrigeration cycle path of the first compressor 1 also includes the first compressor 1, as well as the condenser 7, evaporator 8, and expansion valve 9.

[0084] The refrigeration cycle path of the first compressor 1 is as follows: first compressor 1 - condenser 7 - throttle valve 9 - evaporator 8 - first compressor 1.

[0085] In some embodiments, such as Figure 2 As shown, the refrigeration cycle path of the first compressor 1 also includes the first compressor 1, as well as the condenser 7, evaporator 8, first throttle valve 91, second throttle valve 92, and flash evaporator 10, etc.

[0086] The refrigeration cycle path of the first compressor 1 is as follows: first compressor 1 - condenser 7 - first throttle valve 91 - flash evaporator 10 - second throttle valve 92 - evaporator 8 - first compressor 1. Among them, the flash evaporator 10 is also connected to the first compressor 1 to supply gas and increase enthalpy for the first compressor 1.

[0087] The first compressor 1 includes a two-stage compressor, which includes a low-pressure stage component 12 and a high-pressure stage component 13. The flash generator 10 is connected between the low-pressure stage component 12 and the high-pressure stage component 13 of the two-stage compressor through a pipeline.

[0088] In some embodiments, the refrigeration system includes an air conditioning refrigeration system. The refrigeration system has both cooling and heating functions. The refrigeration cycle path of the first compressor 1 includes a cooling path and a heating path.

[0089] Some embodiments provide a method of operating a gas supply system for a compressor gas bearing, comprising:

[0090] Set the differential pressure value P X =P1-P2; where P1 is the gas pressure in the gas supply tank 3; and P2 is the internal pressure of the first compressor 1;

[0091] When P X <P T Reduce the opening of regulating valve 61;

[0092] When P X >P T Increase the opening of regulating valve 61;

[0093] When P X =P TThe opening degree of regulating valve 61 remains unchanged;

[0094] Among them, P T The target gas pressure value required for the gas bearing of the first compressor 1 to operate normally and stably.

[0095] In some embodiments, the gas supply system for the gas bearing of the compressor includes a second compressor 2, and the intake pipe 4 includes a first pipe 41 and a second pipe 42 connected in parallel, with the second compressor 2 disposed on the first pipe 41.

[0096] In P3-P2 <P min At that time, the second compressor (2) starts, and according to P X With P T Adjust the opening degree of regulating valve 61 according to the relationship;

[0097] P3-P2≥P min At that time, the second compressor (2) shuts down, and according to P X With P T Adjust the opening degree of the regulating valve (61) according to the relationship;

[0098] Where P3 is the gas pressure at the first location; P min The minimum gas pressure required for the gas bearing of the first compressor (1) to operate normally and stably is P. min ≤P T .

[0099] In some embodiments, when the first compressor 1 is in a newly started state, or the first compressor 1 is off, or the first compressor 1 is in an unstable operating state, P3-P2 <P min .

[0100] When the first compressor 1 is in a stable operating state, P3 - P2 ≥ P min .

[0101] In some embodiments, a first pipe 41 and a second pipe 42 are connected in parallel. The second compressor 2 is located on the first pipe 41 and can selectively supply gas to the gas supply tank 3. The second pipe 42 continuously supplies gas to the gas supply tank 3. The outlet pipe 5 supplies gas to the gas bearing. The opening of the pressure regulating valve 61 on the return pipe 6 is adjustable to regulate the gas pressure in the gas supply tank 3. Therefore, through the cooperation of various components, a stable pressure of gaseous refrigerant can be provided to the gas bearing, which is beneficial to the reliable and stable operation of the unit.

[0102] The following is a specific embodiment of the gas supply system for the gas bearing of the compressor and the refrigeration system in which it is located. In this specific embodiment, the gas supply system for the gas bearing of the compressor and the refrigeration system in which it is located include a first compressor 1, a second compressor 2, a gas supply tank 3, a first pipe 41, a second pipe 42, a gas outlet pipe 5, a gas return pipe 6, a pressure regulating valve 61, a condenser 7, an evaporator 8, and a throttling valve 9, etc.

[0103] A first pressure sensor 11 is installed on the first compressor 1 to detect the internal pressure of the first compressor 1. A second pressure sensor 31 is installed on the gas supply tank 3 to detect the gas pressure inside the gas supply tank 3.

[0104] The discharge port of the first compressor 1 is connected to the inlet of the condenser 7. A third pressure sensor 71 is installed on the condenser 7 to detect the internal pressure of the condenser 7. The outlet of the condenser 7 is connected to the inlet of the throttle valve 9, and the outlet of the throttle valve 9 is connected to the inlet of the evaporator 8. A fourth pressure sensor 81 is installed on the evaporator 8 to detect the internal pressure of the evaporator 8. The outlet of the evaporator 8 is connected to the air inlet of the first compressor 1.

[0105] The inlet of the first pipe 41 is connected to the condenser 7, and the outlet of the first pipe 41 is connected to the gas supply tank 3. The first pipe 41 is equipped with a second compressor 2, a first direction control element 411 and a first filter 412.

[0106] The inlet of the second pipe 42 is connected to the condenser 7, and the outlet of the second pipe 42 is connected to the gas supply tank 3. A second filter 422 and a second direction control element 421 are installed on the second pipe 42.

[0107] The inlet of the outlet pipe 5 is connected to the gas supply tank 3, and the outlet of the outlet pipe 5 is connected to the first compressor 1, for supplying gas to the gas bearing in the first compressor 1.

[0108] The inlet of the return gas pipe 6 is connected to the gas supply tank 3, and the outlet of the return gas pipe 6 is connected to the evaporator 8. The pressure regulating valve 61 is located in the return gas pipe 6 and is used to regulate the gas flow rate in the return gas pipe 61.

[0109] Set the differential pressure value P X =P1-P2; where P1 is the gas pressure value in the gas supply tank 3; and P2 is the internal pressure value of the first compressor 1.

[0110] Set P T and P min P T The target gas pressure value required for the gas bearing of the first compressor 1 to operate normally and stably. P min The minimum gas pressure required for the gas bearing of the first compressor 1 to operate normally and stably. P T≥P min .

[0111] The cross-sectional area of ​​the vent holes in a gas bearing is constant, therefore the gas flow rate through the bearing is related to P. X It depends on the size, P X The larger the value, the greater the gas supply flow, and vice versa, according to P. X With P T Adjust the opening of regulating valve 61 to further adjust P. X The value determines the amount of gas supplied to the gas bearing.

[0112] When P X =P T This indicates that it can provide the air flow rate required for the normal and stable operation of the gas bearing, P. X The more stable the gas supply, the more stable the unit operation. At this time, the opening of the regulating valve 61 is kept unchanged.

[0113] When P X <P T Decrease the opening of regulating valve 61 to increase P. X value.

[0114] When P X >P T Increase the opening of regulating valve 61 to reduce P. X value.

[0115] During unit operation, the gas supply system includes gas supply mode one and gas supply mode two, depending on the different states of the unit.

[0116] Gas supply mode 1: When the unit is in the start-up process, shutdown process, or abnormal stable operation state, the condenser 7 cannot meet the gas bearing's gas supply requirements, or when the difference between the internal pressure P3 of the condenser 7 and the internal pressure P2 of the first compressor 1 is less than P... min That is: P3-P2 <P min Condenser 7 cannot supply enough gas to the gas bearing, so the second compressor 2 starts. At this time, it can be determined according to P. X With P T The relationship is adjusted by regulating the opening of the regulating valve 61.

[0117] In other words, in gas supply mode one, when the second compressor 2 is not running, the gas pressure in the gas supply tank 3 may be less than, greater than, or equal to the internal pressure of the condenser 7. However, a second directional control element 21 is installed on the second pipe 42 between the condenser 7 and the gas supply tank 3, meaning that the refrigerant can only flow from the condenser 7 to the gas supply tank 3, and not from the gas supply tank 3 to the condenser 7. After the second compressor 2 has been running for a period of time, the internal pressure of the condenser 7 becomes less than the internal pressure of the gas supply tank 3.

[0118] Gas supply mode two: When the difference between the internal pressure P3 of the condenser 7 and the internal pressure P2 of the first compressor 1 is greater than or equal to P... min That is: P3 - P2 ≥ P min At this time, condenser 7 can meet the gas supply requirements of the gas bearing, and the second compressor 2 is shut down. At this point, it can be determined according to P... X With P T The relationship is adjusted by regulating the opening of the regulating valve 61.

[0119] In gas supply mode two, the internal pressure of gas supply tank 3 is less than or equal to the internal pressure of condenser 7.

[0120] Through the cooperation of the second compressor 2 and the regulating valve 61, the second compressor 2 does not have the problem of frequent start-stop, and can achieve a continuous and stable gas supply to the gas bearing, ensuring the reliable and stable operation of the unit.

[0121] In the description of this invention, it should be understood that the use of terms such as "first," "second," and "third" to define components is merely for the purpose of distinguishing the aforementioned components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0122] Furthermore, in the absence of explicit denial, the technical features of one embodiment can be advantageously combined with one or more other embodiments.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A gas supply system for a gas bearing in a compressor, characterized in that, include: The first compressor (1) and its refrigeration cycle path, wherein the gas bearing is located on the first compressor (1). Gas supply tank (3); An intake pipe (4) connects the gas supply tank (3) to the first part of the refrigeration cycle path. The intake pipe (4) is configured to guide the gaseous refrigerant in the refrigeration cycle path to the gas supply tank (3). The intake pipe (4) includes a first pipe (41) and a second pipe (42) connected in parallel. An outlet pipe (5) connects the gas supply tank (3) to the first compressor (1). The outlet pipe (5) is configured to direct the gaseous refrigerant in the gas supply tank (3) to the gas bearing to supply gas to the gas bearing. A return pipe (6) connects the gas supply tank (3) to a second part of the refrigeration cycle path. The return pipe (6) is configured to direct the gaseous refrigerant in the gas supply tank (3) to the refrigeration cycle path. as well as A regulating valve (61) is provided in the return gas pipe (6). The opening degree of the regulating valve (61) is adjustable to regulate the gas flow rate in the return gas pipe (6). The second compressor (2) is located in the first pipe (41), and the exhaust end of the second compressor (2) is connected to the gas supply tank (3). The second compressor (2) is configured to work selectively to pressurize the gaseous refrigerant in the first pipe (41) and send it to the gas supply tank (3). Under normal and stable operating conditions of the first compressor (1), the gas pressure at the first part is greater than the gas pressure at the second part.

2. The gas supply system for the gas bearing of the compressor as described in claim 1, characterized in that, Includes a first direction control element (411), which is disposed on the first pipe (41) and located between the exhaust end of the second compressor (2) and the gas supply tank (3). The first direction control element (411) is configured to control the flow of gaseous refrigerant from the second compressor (2) to the gas supply tank (3).

3. The gas supply system for the gas bearing of the compressor as described in claim 1, characterized in that, Includes a second direction control element (421), which is disposed on the second pipe (42) and is configured to control the flow of gaseous refrigerant from the first part of the refrigeration cycle path to the gas supply tank (3).

4. The gas supply system for the gas bearing of the compressor as described in claim 1, characterized in that, The second compressor (2) is configured to start before the first compressor (1) starts, in the initial start-up state, or in an unstable working state, so as to pressurize the gaseous refrigerant in the first pipe (41) and send it to the gas supply tank (3).

5. The gas supply system for the gas bearing of the compressor as described in claim 1, characterized in that, Includes a condenser (7) located in the refrigeration cycle path, and the first part includes a part on the condenser (7).

6. The gas supply system for the gas bearing of the compressor as described in claim 1, characterized in that, Includes an evaporator (8) located in the refrigeration cycle path, and the second part includes a portion on the evaporator (8).

7. The gas supply system for the gas bearing of the compressor as described in claim 1, characterized in that, Includes a flash generator (10) disposed in the refrigeration cycle path, and the second part includes a portion on the flash generator (10).

8. The gas supply system for the gas bearing of the compressor as described in claim 1, characterized in that, It includes a first pressure sensor (11) and a second pressure sensor (31). The first pressure sensor (11) is located on the first compressor (1) and is configured to detect the internal pressure of the first compressor (1). The second pressure sensor (31) is located on the gas supply tank (3) and is configured to detect the gas pressure in the gas supply tank (3).

9. The gas supply system for a compressor gas bearing as described in claim 5, characterized in that, Includes a third pressure sensor (71), which is located in the condenser (7) and configured to detect the internal pressure of the condenser (7).

10. A refrigeration system, characterized in that, The gas supply system includes the gas bearing for the compressor as described in any one of claims 1 to 9.

11. A method of operating the gas supply system for a compressor gas bearing as described in claim 1, characterized in that, include: Set differential pressure value ;in, The gas pressure value inside the gas supply tank (3); The internal pressure value of the first compressor (1); when Reduce the opening of the regulating valve (61); when Increase the opening of the regulating valve (61); when The opening degree of the regulating valve (61) remains unchanged; in, The target gas pressure value required for the gas bearing of the first compressor (1) to work normally and stably.

12. The method of operating the gas supply system for the gas bearing of the compressor as described in claim 11, characterized in that, The gas supply system for the gas bearing of the compressor includes a second compressor (2), and the intake pipe (4) includes a first pipe (41) and a second pipe (42) connected in parallel, with the second compressor (2) located on the first pipe (41). exist At that time, the second compressor (2) starts, and according to and Adjust the opening degree of the regulating valve (61) according to the relationship; exist At that time, the second compressor (2) shuts down, and according to and Adjust the opening degree of the regulating valve (61) according to the relationship; in, This refers to the gas pressure at the first location; The minimum gas pressure required for the gas bearing of the first compressor (1) to operate normally and stably. .

13. The method of operating the gas supply system for the gas bearing of the compressor as described in claim 12, characterized in that, When the first compressor (1) is in the newly started state, or the first compressor (1) is off, or the first compressor (1) is in an unstable working state, ; When the first compressor (1) is in a stable operating state, .

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