Refrigerating system and oil return control method

Abstract

The invention provides a refrigerating system and an oil return control method. The system comprises a refrigerating compressor, an oil separator, a condenser, a throttling device and an evaporator which are connected with one another to form a refrigerating loop. The enrichment device is connected into the refrigerating circuit, a containing cavity for containing a mixture is formed in the enrichment device, and the mixture mainly comprises lubricating oil, a gaseous refrigerant and a liquid refrigerant; and the oil product monitoring module is connected with the enrichment device and used for detecting indexes of the mixture and adjusting the connection state of the enrichment device and the refrigeration compressor and the connection state of the enrichment device and the oil collector according to the indexes. The enrichment device and the oil product monitoring module connected with the enrichment device are arranged in the oil return system, real-time monitoring and automatic recycling of lubricating oil products in the refrigerating system are achieved, recycling or discharging of the lubricating oil is judged by detecting the quality of the oil products, the flowing direction of the lubricating oil is adjusted, the use range of the return oil is widened, and the oil return system has the advantages of being simple in structure and convenient to use. And stable operation of the refrigeration compressor is protected.

Description

Technical Field

[0001] This invention relates to the field of refrigeration technology, and in particular to a refrigeration system and an oil return control method. Background Technology

[0002] In related technologies, such as Figure 1 As shown, oil return systems in refrigeration systems suffer from complex piping layouts and cannot guarantee the quality of the reused lubricating oil. For example, the commonly used ejector oil return method, often found in modular systems, struggles to ensure the quality of the reused lubricating oil. Furthermore, automatic oil draining is primarily used in ammonia refrigeration systems. Its purpose is to improve the heat exchange efficiency of the evaporator by draining the refrigerant oil from it, but it cannot achieve oil reuse or monitor the oil quality. Summary of the Invention

[0003] This invention provides a refrigeration system and an oil return control method to solve the defects of existing refrigeration systems, such as complex oil return connection pipeline layout and inability to guarantee the quality of the lubricating oil to be reused.

[0004] According to a first aspect of the present invention, a refrigeration system includes: a refrigeration compressor, an oil separator, a condenser, a throttling device, and an evaporator connected to each other to form a refrigeration circuit; an enrichment unit connected to the refrigeration circuit and having an internal cavity for containing a mixture, the mixture mainly comprising lubricating oil, gaseous refrigerant, and liquid refrigerant; and an oil monitoring module connected to the enrichment unit for detecting indicators of the mixture and adjusting the enrichment unit and the refrigeration compressor, as well as the connection state between the enrichment unit and the oil collector, according to the indicators.

[0005] According to one embodiment of the present invention, the device further includes: a pressure reducing pipe, one end of which is connected to the enrichment device, and the other end of which is connected to the suction port of the refrigeration compressor, for introducing gaseous refrigerant in the enrichment device into the refrigeration compressor; and a first solenoid valve disposed on the path of the pressure reducing pipe.

[0006] Specifically, this embodiment provides an implementation of a pressure reducing pipe and a first solenoid valve.

[0007] According to one embodiment of the present invention, it further includes: a booster pipe, one end of which is connected to the enrichment unit, and the other end of which is connected between the oil separator and the condenser, for introducing gaseous refrigerant in the oil separator into the enrichment unit; and a second solenoid valve, which is disposed on the path of the booster pipe.

[0008] Specifically, this embodiment provides an implementation of a pressure boosting pipe and a second solenoid valve.

[0009] According to one embodiment of the present invention, it further includes: an oil inlet pipe, one end of which is connected to the enrichment device and the other end of which is connected to the evaporator, for introducing lubricating oil in the evaporator into the enrichment device; and a first shut-off valve, which is disposed on the path of the oil inlet pipe.

[0010] Specifically, this embodiment provides an implementation of an oil inlet pipe and a first shut-off valve.

[0011] According to one embodiment of the present invention, it further includes: an oil drain pipe, one end of which is connected to the enrichment device, and the other end of which is connected to the refrigeration compressor and the oil collector respectively, for draining the oil into the refrigeration compressor or the oil collector; a third solenoid valve, disposed on the lubricating oil path connecting the oil drain pipe and the refrigeration compressor; and a fourth solenoid valve, disposed on the lubricating oil path connecting the oil drain pipe and the oil collector.

[0012] Specifically, this embodiment provides an implementation of an oil drain pipe, a third solenoid valve, and a fourth solenoid valve.

[0013] According to one embodiment of the present invention, it further includes: a second shut-off valve disposed on the lubricating oil pipeline connecting the condenser and the oil collector; a third shut-off valve disposed on the lubricating oil pipeline connecting the evaporator and the oil collector; and a fourth shut-off valve disposed on the lubricating oil pipeline connecting the enricher and the oil separator.

[0014] Specifically, this embodiment provides an implementation of a second shut-off valve, a third shut-off valve, and a fourth shut-off valve.

[0015] According to a second aspect of the present invention, a method for controlling the oil return of the above-mentioned refrigeration system includes:

[0016] Based on the refrigeration operation mode of the refrigeration system, the operating parameters of the refrigeration compressor are obtained;

[0017] Based on the operating parameters, the refrigeration compressor is identified as being in a fault state or stopped state, and all solenoid valves are controlled to be in the closed state.

[0018] Based on the operating parameters, the refrigeration compressor is identified as being in the refrigeration operation mode. The index parameters of the lubricating oil in the enrichment unit are obtained, and an oil return control strategy is generated based on the index parameters. The oil return control strategy is used at least to adjust the working state of the solenoid valve.

[0019] According to one embodiment of the present invention, the step of obtaining the index parameters of the lubricating oil in the enrichment device specifically includes:

[0020] Based on the refrigeration compressor being in the refrigeration operation mode, a first control logic is generated. Under the first control logic, the solenoid valve between the enrichment unit and the refrigeration compressor is in the open state, and the other solenoid valves are in the closed state.

[0021] Based on the first control logic running for a first preset time, the index parameters of the lubricating oil in the enricher are obtained.

[0022] Specifically, this embodiment provides an implementation method for obtaining the index parameters of the lubricating oil in the enricher.

[0023] According to one embodiment of the present invention, the step of generating a return oil control strategy based on the index parameters specifically includes:

[0024] Based on the fact that the index parameters meet the preset index threshold, a second control logic is generated. Under the second control logic, the solenoid valve on the lubricating oil path connecting the enricher and the oil separator is in the open state, and the other solenoid valves are in the closed state. The solenoid valve on the lubricating oil path connecting the enricher and the refrigeration compressor through the oil detection module is periodically opened at a preset interval.

[0025] Based on the second control logic, the operation reaches a second preset duration, and the operating parameters of the refrigeration compressor are obtained, wherein the length of the second preset duration is greater than the first preset duration.

[0026] Specifically, this embodiment provides an implementation method for generating a return oil control strategy based on the aforementioned index parameters.

[0027] According to one embodiment of the present invention, the step of generating a return oil control strategy based on the index parameters specifically includes:

[0028] Based on the fact that the index parameters do not meet the preset index threshold, a third control logic is generated. Under the third control logic, the solenoid valves on the lubricating oil path connecting the enricher and the oil separator, as well as the enricher and the oil collector, are in the open state, while the other solenoid valves are in the closed state.

[0029] Based on the fact that the third control logic meets the preset conditions, a prompt will be made to manually check the lubricating oil in the oil separator;

[0030] Based on the fact that the third control logic does not meet the preset conditions, the index parameters of the lubricating oil in the enricher are continuously acquired, and a judgment is made according to the preset index threshold.

[0031] The preset conditions include at least the third control logic reaching a third preset duration, and the number of times the solenoid valve on the lubricating oil path connecting the enricher and the oil collector is opened is greater than a preset number of openings. The third preset duration is greater than the first preset duration, and the third preset duration is less than the second preset duration.

[0032] Specifically, this embodiment provides an implementation method for generating a return oil control strategy based on the aforementioned index parameters.

[0033] The above-mentioned one or more technical solutions of the present invention have at least one of the following technical effects: The refrigeration system and oil return control method provided by the present invention, by setting an enrichment device in the oil return system and an oil monitoring module connected to the enrichment device, realizes real-time monitoring and automatic reuse of lubricating oil in the refrigeration system, determines whether the lubricating oil is reused or discharged by detecting the oil quality, and adjusts the flow direction of the lubricating oil, thus broadening the scope of use of oil return and protecting the stable operation of the refrigeration compressor. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the existing refrigeration system layout;

[0036] Figure 2 This is a schematic diagram of the layout of the refrigeration system provided by the present invention;

[0037] Figure 3 This is a schematic flowchart of the oil return control method for the refrigeration system provided by the present invention.

[0038] Figure label:

[0039] 10. Refrigeration compressor; 20. Oil separator; 30. Condenser; 40. Throttling device; 50. Evaporator; 60. Enricher; 61. Oil monitoring module; 62. Pressure reducing pipe; 621. First solenoid valve; 63. Pressure boosting pipe; 631. Second solenoid valve; 64. Oil inlet pipe; 641. First shut-off valve; 65. Oil outlet pipe; 651. Third solenoid valve; 652. Fourth solenoid valve; 70. Oil collector; 80. Second shut-off valve; 90. Third shut-off valve; 100. Fourth shut-off valve. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of 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 some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "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 the embodiments of the present 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 limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] The present invention will now be described in detail with reference to specific embodiments.

[0043] In some specific embodiments of the present invention, such as Figure 2 As shown, this solution provides a refrigeration system, including: a refrigeration compressor 10, an oil separator 20, a condenser 30, a throttling device 40, and an evaporator 50 connected to each other to form a refrigeration circuit; an enrichment unit 60 connected to the refrigeration circuit and having an internal cavity for containing a mixture, the mixture mainly including lubricating oil, gaseous refrigerant, and liquid refrigerant; and an oil monitoring module 61 connected to the enrichment unit 60 for detecting the indicators of the mixture and adjusting the enrichment unit 60 and the refrigeration compressor 10, as well as the connection state between the enrichment unit 60 and the oil collector 70, according to the indicators.

[0044] It should be noted that by setting an enricher 60 in the oil return system and an oil monitoring module 61 connected to the enricher 60, the present invention realizes real-time monitoring and automatic reuse of lubricating oil in the refrigeration system, expands the application range of oil return, protects the stable operation of the refrigeration compressor 10, and has the advantages of simple system principle and control scheme, wide applicability, and minimal space occupation. At the same time, it can also prevent liquid refrigerant from entering the refrigeration compressor 10.

[0045] Furthermore, the refrigeration system and oil return control method provided by this invention can be applied to oil-free compressors for ammonia refrigeration or to the development of oil separation equipment with high oil separation efficiency. This can fundamentally solve the problems of complex oil return connection pipeline layout in existing refrigeration systems and the inability to guarantee the quality of the lubricating oil to be reused.

[0046] In some possible embodiments of the present invention, it further includes: a pressure reducing pipe 62, one end of which is connected to the enrichment unit 60, and the other end of which is connected to the suction port of the refrigeration compressor 10, for introducing the gaseous refrigerant in the enrichment unit 60 into the refrigeration compressor 10; and a first solenoid valve 621, which is disposed on the path of the pressure reducing pipe 62.

[0047] Specifically, this embodiment provides an implementation of a pressure reducing pipe 62 and a first solenoid valve 621. By setting the pressure reducing pipe 62, the enrichment unit 60 is connected to the suction port of the refrigeration compressor 10, so that the enrichment unit 60 is in a low-pressure state, thereby reducing the refrigerant content in the recycled lubricating oil.

[0048] Furthermore, the first solenoid valve 621 enables automatic control of the opening and closing of the pressure reducing pipe 62, so as to adjust the opening and closing of the pressure reducing pipe 62 according to the oil quality of different lubricating oils.

[0049] In some possible embodiments of the present invention, it further includes: a booster pipe 63, one end of which is connected to the enricher 60, and the other end of which is connected between the oil separator 20 and the condenser 30, for introducing the gaseous refrigerant in the oil separator 20 into the enricher 60; and a second solenoid valve 631, which is disposed on the path of the booster pipe 63.

[0050] Specifically, this embodiment provides an implementation of a booster pipe 63 and a second solenoid valve 631. By setting up the booster pipe 63, the high-pressure gas in the oil separator 20 is introduced into the enricher 60, and the lubricating oil in the enricher 60 is recycled to the refrigeration compressor 10 by relying on the pressure difference.

[0051] Furthermore, the second solenoid valve 631 enables automatic control of the on / off state of the booster pipe 63, so as to adjust the on / off state of the booster pipe 63 according to the different types of lubricating oil.

[0052] In some possible embodiments of the present invention, it further includes: an oil inlet pipe 64, one end of which is connected to the enrichment unit 60 and the other end of which is connected to the evaporator 50, for introducing the lubricating oil in the evaporator 50 into the enrichment unit 60; and a first shut-off valve 641, which is disposed on the path of the oil inlet pipe 64.

[0053] Specifically, this embodiment provides an implementation of an oil inlet pipe 64 and a first shut-off valve 641. By setting the oil inlet pipe 64, the enrichment unit 60 is connected to the evaporator 50, so that the mixture in the evaporator 50 can enter the enrichment unit 60, thereby reducing the refrigerant content in the recycled lubricating oil.

[0054] Furthermore, by setting the first shut-off valve 641, manual control of the opening and closing of the oil inlet pipe 64 is realized. In case of malfunction or the solenoid valve malfunctioning, the lubricating oil can be discharged and recovered manually.

[0055] In some possible embodiments of the present invention, it further includes: an oil drain pipe 65, one end of which is connected to the enrichment collector 60, and the other end of which is connected to the refrigeration compressor 10 and the oil collector 70 respectively, for draining oil into the refrigeration compressor 10 or the oil collector 70; a third solenoid valve 651, which is disposed on the lubricating oil path connecting the oil drain pipe 65 and the refrigeration compressor 10; and a fourth solenoid valve 652, which is disposed on the lubricating oil path connecting the oil drain pipe 65 and the oil collector 70.

[0056] Specifically, this embodiment provides an implementation of an oil drain pipe 65, a third solenoid valve 651, and a fourth solenoid valve 652. By setting up the oil drain pipe 65, the lubricating oil in the enrichment device 60 is transported to the refrigeration compressor 10 or the oil collector 70, thereby realizing real-time monitoring and automatic reuse of the lubricating oil in the refrigeration system. The lubricating oil is reused or discharged by detecting the quality of the oil.

[0057] Furthermore, the installation of the third solenoid valve 651 and the fourth solenoid valve 652 enables the adjustment of the connection between the enrichment collector 60 and the refrigeration compressor 10, as well as between the enrichment collector 60 and the oil collector 70.

[0058] In some possible embodiments of the present invention, it further includes: a second shut-off valve 80, disposed on the lubricating oil pipeline connecting the condenser 30 and the oil collector 70; a third shut-off valve 90, disposed on the lubricating oil pipeline connecting the evaporator 50 and the oil collector 70; and a fourth shut-off valve 100, disposed on the lubricating oil pipeline connecting the enrichment collector 60 and the oil separator 20.

[0059] Specifically, this embodiment provides an implementation of a second shut-off valve 80, a third shut-off valve 90, and a fourth shut-off valve 100. By setting the second shut-off valve 80, the third shut-off valve 90, and the fourth shut-off valve 100, the on / off of each flow path in the refrigeration system can be manually adjusted. When the solenoid valve is not working or malfunctions, the lubricating oil can be collected and discharged by manual adjustment, reducing the generation of hazardous waste, protecting the environment, and saving operating costs.

[0060] In some specific embodiments of the present invention, such as Figure 2 and Figure 3 As shown, this solution provides a method for controlling the oil return of the above-mentioned refrigeration system, including:

[0061] Based on the refrigeration operation mode of the refrigeration system, the operating parameters of the refrigeration compressor 10 are obtained;

[0062] Based on the operating parameters, the refrigeration compressor 10 is identified as being in a fault state or stopped state, and all solenoid valves are controlled to be in the closed state.

[0063] Based on the operating parameters indicating that the refrigeration compressor 10 is in refrigeration operation mode, the index parameters of the lubricating oil in the enrichment 60 are obtained, and an oil return control strategy is generated based on the index parameters. The oil return control strategy is used to adjust the working state of the solenoid valve at least.

[0064] It should be noted that by adjusting the corresponding solenoid valve based on the monitored parameters of the lubricating oil in the refrigeration circuit, the system can determine whether the lubricating oil should be reused or discharged based on its quality, and adjust the flow direction of the lubricating oil.

[0065] In possible embodiments, the index parameters include at least one or a combination of several of the following: dynamic viscosity, kinematic viscosity, water content, total number of contaminating particles, acidity, and turbidity of the mixture.

[0066] In some possible embodiments of the present invention, the step of obtaining the index parameters of the lubricating oil in the enrichment device 60 specifically includes:

[0067] Based on the fact that the refrigeration compressor 10 is in refrigeration operation mode, the first control logic is generated. Under the first control logic, the solenoid valve between the enrichment unit 60 and the refrigeration compressor 10 is in the open state, and the other solenoid valves are in the closed state.

[0068] Based on the first control logic, the operation reaches the first preset time and obtains the index parameters of the lubricating oil in the enricher 60.

[0069] Specifically, this embodiment provides an implementation method for obtaining the index parameters of the lubricating oil in the enrichment unit 60. According to the operating state of the refrigeration compressor 10, a corresponding first control logic is generated. When the refrigeration compressor 10 is in the refrigeration operation mode, the lubricating oil in the entire refrigeration system circulates until the first control logic has been running for a first preset time. The oil quality index of the lubricating oil in the enrichment unit 60 is obtained and judged, and then the opening and closing of the corresponding solenoid valve is adjusted to realize the adjustment of the corresponding circuit according to the different qualities of the oil, so as to realize the recovery and discharge of the lubricating oil.

[0070] In some possible embodiments of the present invention, the step of generating a return oil control strategy based on index parameters specifically includes:

[0071] Based on the index parameters meeting the preset index threshold, a second control logic is generated. Under the second control logic, the solenoid valve on the lubricating oil path connecting the enricher 60 and the oil separator 20 is in the open state, and the other solenoid valves are in the closed state. The solenoid valve on the lubricating oil path connecting the enricher 60 and the refrigeration compressor 10 through the oil detection module is periodically opened at a preset interval.

[0072] Based on the second control logic, the operation reaches the second preset time and the operating parameters of the refrigeration compressor 10 are obtained, wherein the length of the second preset time is greater than the first preset time.

[0073] Specifically, this embodiment provides an implementation method for generating an oil return control strategy based on index parameters. When the index parameters of the lubricating oil meet the preset index threshold, the lubricating oil and gaseous refrigerant in the enrichment 60 are returned to the refrigeration compressor 10 by adjusting the on / off state of the solenoid valve. During the return process, the pressure difference in the enrichment 60 is used to achieve the return, namely the low pressure of the enrichment 60 and the high pressure of the oil separator 20. This solves the problem that the existing ejector oil return relies on the pressure difference between the evaporation pressure and the suction port of the refrigeration compressor 10 as the oil return driving force, resulting in low oil return efficiency and a large amount of oil accumulation in the evaporator 50, which seriously affects the heat exchange efficiency of the evaporator 50.

[0074] This solves the problem that, during the compressor's intake process, some gas flows back from the exhaust port to the intake port and enters the compression chamber, which is caused by the existing ejector oil return process.

[0075] In some possible embodiments of the present invention, the step of generating a return oil control strategy based on index parameters specifically includes:

[0076] Based on the fact that the index parameters do not meet the preset index threshold, a third control logic is generated. Under the third control logic, the solenoid valves on the lubricating oil path connecting the enricher 60 and the oil separator 20, as well as the enricher 60 and the oil collector 70, are in the open state, while the other solenoid valves are in the closed state.

[0077] Based on the third control logic meeting the preset conditions, a prompt is made to manually check the lubricating oil in the oil separator 20;

[0078] Based on the fact that the third control logic does not meet the preset conditions, the index parameters of the lubricating oil in the enricher 60 are continuously acquired, and a judgment is made according to the preset index threshold.

[0079] Among them, the preset conditions include at least the third control logic reaching the third preset duration, and the number of times the solenoid valve on the lubricating oil path connecting the enricher 60 and the oil collector 70 is opened is greater than the preset number of openings, the third preset duration is greater than the first preset duration, and the third preset duration is less than the second preset duration.

[0080] Specifically, this embodiment provides an implementation method for generating a return oil control strategy based on index parameters. When the index parameters of the lubricating oil do not meet the preset index threshold, it indicates that the lubricating oil needs to be replaced. By adjusting the opening and closing of the solenoid valve and setting the duration of the third control logic, the lubricating oil in the enrichment unit 60 is discharged into the oil collector 70, thus realizing the recovery of lubricating oil that does not meet the index requirements.

[0081] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0082] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0083] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "method," "specific method," or "some methods," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or method is included in at least one embodiment or method of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or method. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or methods. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or methods described in this specification, as well as the features of different embodiments or methods.

[0084] Finally, it should be noted that the above embodiments are only for illustrating the present invention and not for limiting the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and should be covered within the scope of the claims of the present invention.

Claims

1. A refrigeration system, characterized in that, include: A refrigeration compressor (10), an oil separator (20), a condenser (30), a throttling device (40), and an evaporator (50) are connected to each other to form a refrigeration circuit. The enrichment unit (60) is connected to the refrigeration circuit and has a cavity inside for containing a mixture, which mainly includes lubricating oil, gaseous refrigerant and liquid refrigerant; An oil monitoring module (61) is connected to the enrichment unit (60) and is used to detect the index of the mixture and adjust the enrichment unit (60) and the refrigeration compressor (10) and the connection status of the enrichment unit (60) and the oil collector (70) according to the index.

2. The refrigeration system according to claim 1, characterized in that, Also includes: A pressure reducing pipe (62) is provided, one end of which is connected to the enrichment unit (60), and the other end of which is connected to the suction port of the refrigeration compressor (10) for introducing the gaseous refrigerant in the enrichment unit (60) into the refrigeration compressor (10). A first solenoid valve (621) is disposed on the path of the pressure reducing pipe (62).

3. The refrigeration system according to claim 1, characterized in that, Also includes: A booster pipe (63) is provided, one end of which is connected to the enricher (60), and the other end of which is connected between the oil separator (20) and the condenser (30) to introduce the gaseous refrigerant in the oil separator (20) into the enricher (60). A second solenoid valve (631) is disposed on the path of the booster pipe (63).

4. The refrigeration system according to claim 1, characterized in that, Also includes: An oil inlet pipe (64) is provided, one end of which is connected to the enrichment unit (60) and the other end of which is connected to the evaporator (50), for introducing the lubricating oil in the evaporator (50) into the enrichment unit (60). A first shut-off valve (641) is disposed on the path of the oil inlet pipe (64).

5. The refrigeration system according to claim 1, characterized in that, Also includes: An oil drain pipe (65) is provided, one end of which is connected to the enrichment device (60), and the other end of which is connected to the refrigeration compressor (10) and the oil collector (70) respectively, for draining the oil into the refrigeration compressor (10) or the oil collector (70). The third solenoid valve (651) is located on the lubricating oil path connecting the oil drain pipe (65) and the refrigeration compressor (10); The fourth solenoid valve (652) is located on the lubricating oil path connecting the oil drain pipe (65) and the oil collector (70).

6. The refrigeration system according to any one of claims 1 to 5, characterized in that, Also includes: The second shut-off valve (80) is installed on the lubricating oil pipeline connecting the condenser (30) and the oil collector (70); The third shut-off valve (90) is installed on the lubricating oil pipeline connecting the evaporator (50) and the oil collector (70); The fourth shut-off valve (100) is installed on the lubricating oil pipeline connecting the enricher (60) and the oil separator (20).

7. A method for controlling the oil return of a refrigeration system according to any one of claims 1 to 6, characterized in that, include: Based on the refrigeration operation mode of the refrigeration system, the operating parameters of the refrigeration compressor (10) are obtained; Based on the operating parameters, the refrigeration compressor (10) is identified as being in a fault state or a stopped state, and all solenoid valves are controlled to be in a closed state. Based on the operating parameters, the refrigeration compressor (10) is identified as being in the refrigeration operation mode. The index parameters of the lubricating oil in the enrichment unit (60) are obtained, and an oil return control strategy is generated based on the index parameters. The oil return control strategy is used at least to adjust the working state of the solenoid valve.

8. The oil return control method for a refrigeration system according to claim 7, characterized in that, The steps for obtaining the index parameters of the lubricating oil in the enricher (60) specifically include: Based on the refrigeration compressor (10) being in the refrigeration operation mode, a first control logic is generated. Under the first control logic, the solenoid valve between the enrichment unit (60) and the refrigeration compressor (10) is in the open state, and the other solenoid valves are in the closed state. Based on the first control logic running for a first preset time, the index parameters of the lubricating oil in the enricher (60) are obtained.

9. The oil return control method for a refrigeration system according to claim 8, characterized in that, The step of generating a return oil control strategy based on the index parameters specifically includes: Based on the index parameters meeting the preset index threshold, a second control logic is generated. Under the second control logic, the solenoid valve on the lubricating oil path connecting the enricher (60) and the oil separator (20) is in the open state, and the other solenoid valves are in the closed state. The enricher (60) is periodically opened at a preset interval through the solenoid valve on the lubricating oil path connecting the oil detection module and the refrigeration compressor (10). Based on the second control logic, the operation reaches the second preset duration, and the operating parameters of the refrigeration compressor (10) are obtained, wherein the length of the second preset duration is greater than the first preset duration.

10. The oil return control method for a refrigeration system according to claim 9, characterized in that, The step of generating a return oil control strategy based on the index parameters specifically includes: Based on the fact that the index parameters do not meet the preset index threshold, a third control logic is generated. Under the third control logic, the solenoid valves on the lubricating oil path connecting the enricher (60) and the oil separator (20), as well as the enricher (60) and the oil collector (70), are in the open state, and the other solenoid valves are in the closed state. Based on the fact that the third control logic meets the preset conditions, a prompt is made to manually check the lubricating oil in the oil separator (20); Based on the fact that the third control logic does not meet the preset conditions, the index parameters of the lubricating oil in the enricher (60) are continuously acquired, and a judgment is made according to the preset index threshold. The preset conditions include at least the third control logic reaching a third preset duration, and the number of times the solenoid valve on the lubricating oil path connected to the enricher (60) and the oil collector (70) is opened is greater than a preset number of times. The third preset duration is greater than the first preset duration and the third preset duration is less than the second preset duration.

Images