Outdoor unit system and air conditioning unit

Abstract

The application relates to an outdoor unit system and an air conditioning unit. A one-way oil return valve is arranged between the suction port of a compressor and the bypass outlet of an oil separator of the outdoor unit system, and the one-way oil return valve can realize one-way conduction from the bypass outlet of the oil separator to the suction port of the compressor. When the air conditioning unit operates at a high first load, the one-way oil return valve is open, and the separated lubricating oil is transported back to the compressor; when the air conditioning unit operates at a low second load, the one-way oil return valve is closed, and the oil return operation is terminated. In this way, the oil return operation is not required in real time, the opening frequency of the bypass branch between the oil separator and the compressor is reduced, and thus the influence of the oil separator on the operation energy efficiency of the multi-connected air conditioning unit can be reduced.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and in particular to an outdoor unit system and an air conditioning unit. Background Technology

[0002] With the rapid development of science and technology, air conditioning has been widely used in daily production and life, providing people with a comfortable living environment. Currently, due to the long connecting pipes installed in multi-split air conditioning units, most multi-split air conditioning units are equipped with oil separators to separate refrigerant gas from the lubricating oil mixed in it. This ensures that the lubricating oil can return smoothly to the compressor, while allowing pure refrigerant gas to continue circulating in the unit, preventing mechanical wear or malfunctions of the compressor due to insufficient oil.

[0003] In related technologies, when the oil separator returns oil, it is equivalent to adding a bypass branch, which has an adverse effect on the operating energy efficiency of the multi-split air conditioning unit. Utility Model Content

[0004] Therefore, it is necessary to address the issue of oil separators adversely affecting the operating energy efficiency of multi-split air conditioning units, and propose an outdoor unit system and air conditioning unit to reduce the impact of oil separators on the operating energy efficiency of multi-split air conditioning units.

[0005] This application provides an outdoor unit system, including: an outdoor heat exchange component, an oil separator, a compressor, an oil return check valve, and a gas-liquid separator. The outlet of the oil separator is connected to the outdoor heat exchange component; the exhaust port of the compressor is connected to the inlet of the oil separator; the inlet of the oil return check valve is connected to a side outlet of the oil separator, and the outlet of the oil return check valve is connected to the suction port of the compressor; wherein, under a first load operation, the oil return check valve is open, and under a second load operation, the oil return check valve is closed, where the first load is greater than the second load; the inlet of the gas-liquid separator is connected to the outdoor heat exchange component, and the outlet of the gas-liquid separator is connected to the suction port of the compressor.

[0006] In the aforementioned outdoor unit system, an oil return check valve is installed between the compressor suction port and the bypass outlet of the oil separator. This check valve enables unidirectional flow from the bypass outlet of the oil separator to the compressor suction port. When the air conditioning unit operates at a higher first load, the oil return check valve is open, returning the lubricating oil separated by the oil separator to the compressor. When the air conditioning unit operates at a lower second load, the oil return check valve is closed, terminating the oil return operation. This design allows for oil return under high-load conditions, ensuring oil return to the compressor when the oil discharge rate is high. Under low-load conditions, the oil return check valve is closed to reduce bypass and ensure the air conditioning unit's operational efficiency. This eliminates the need for real-time oil return, reducing the frequency of the bypass branch opening between the oil separator and the compressor, thereby reducing the impact of the oil separator on the operational efficiency of the multi-split air conditioning unit.

[0007] In one embodiment, the outdoor unit system further includes a first flow regulating component, which is connected in series between the inlet of the oil return check valve and the side outlet of the oil separator.

[0008] The above solution involves configuring a first flow regulating component between the side outlet of the oil separator and the inlet of the return oil check valve. This component can assist in throttling and ensuring smooth flow when the return oil check valve is open, thereby improving the reliability of the return oil flow.

[0009] In one embodiment, the first flow regulating component is a first capillary or a first electronic expansion valve.

[0010] The above solution uses a capillary tube or electronic expansion valve as the first flow regulation component, which is simple in structure and easy to implement, effectively saving hardware costs and improving installation convenience.

[0011] In one embodiment, the outdoor unit system further includes a second flow regulating component, a first end of which is connected to the inlet of the return oil check valve and the first flow regulating component, and a second end of which is connected to the outlet of the return oil check valve.

[0012] The above solution also includes a second flow regulating component connected in parallel across the return oil check valve. This allows for the opening of a single branch in low-temperature scenarios to ensure a certain amount of return oil without causing excessive leakage. Simultaneously, in heavy-load scenarios, both branches can be opened for oil return and pressure relief, improving the operational reliability of the outdoor unit system.

[0013] In one embodiment, the second flow regulating component is a second capillary or a second electronic expansion valve.

[0014] The above solution uses a capillary tube or electronic expansion valve as the second flow regulating component, which is simple in structure and easy to implement, effectively saving hardware costs and improving installation convenience.

[0015] In one embodiment, the second flow regulating component includes a third capillary and a switching element, a first end of the third capillary is connected to a first end of the switching element, a second end of the switching element is connected to the inlet of the return oil check valve and the first flow regulating component, and a second end of the third capillary is connected to the outlet of the return oil check valve.

[0016] In the above scheme, the second flow regulation component includes a third capillary tube and a switching element. The third capillary tube can be connected or disconnected under the control of the switching element according to actual needs, so as to realize the controllable shutdown of the parallel branch and improve the controllability of oil return.

[0017] In one embodiment, the return oil check valve includes a housing, a thrust block, and an elastic element. The housing has a communicating inlet and outlet. The first end of the thrust block is located at the inlet of the housing, and the second end of the thrust block is connected to the elastic element. The elastic element is fixedly located inside the housing.

[0018] The above solution uses a housing, thrust block, and elastic element to form a return oil check valve. The thrust block is pushed by overcoming the resistance of the elastic element, thus achieving unidirectional flow control. In this way, adaptive on / off switching can be achieved with a simple structure, without the need for additional control signals, thus balancing energy efficiency and oil return.

[0019] In one embodiment, the outdoor heat exchange assembly includes a plate heat exchanger, a heat exchanger, a third electronic expansion valve, a fourth electronic expansion valve, and a four-way valve. The first end of the plate heat exchanger is connected to the indoor unit system via a liquid pipe. The second end of the plate heat exchanger is connected to the first ends of the third and fourth electronic expansion valves. The second end of the third electronic expansion valve is connected to the third end of the plate heat exchanger. The fourth end of the plate heat exchanger is connected to the compressor. The second end of the fourth electronic expansion valve is connected to the heat exchanger. The heat exchanger is connected to the first end of the four-way valve. The second end of the four-way valve is connected to the outlet of the oil separator. The third end of the four-way valve is connected to the inlet of the gas-liquid separator. The fourth end of the four-way valve is connected to the indoor unit system via a gas pipe.

[0020] The above scheme, in which the outdoor heat exchange component is constructed through a plate heat exchanger, a heat exchanger, a third electronic expansion valve, a fourth electronic expansion valve, and a four-way valve, has the advantages of high energy efficiency in cooling or heating, good economy, and high operating energy efficiency.

[0021] This application also provides an air conditioning unit, including an indoor unit system and the aforementioned outdoor unit system.

[0022] In one embodiment, the air conditioning unit is a multi-split air conditioning unit. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the outdoor unit system structure in one embodiment of this application;

[0025] Figure 2 This is a schematic diagram of the outdoor unit system structure in another embodiment of this application;

[0026] Figure 3 This is a schematic diagram of the outdoor unit system structure in another embodiment of this application;

[0027] Figure 4 This is a schematic diagram of the return oil check valve structure in one embodiment of this application.

[0028] Explanation of reference numerals in the attached figures:

[0029] 10-Outdoor heat exchange component; 20-Oil separator; 30-Compressor; 40-Oil return check valve; 50-First flow regulating component; 60-Second flow regulating component; 70-Gas-liquid separator; 11-Plate heat exchanger; 12-Third electronic expansion valve; 13-Fourth electronic expansion valve; 14-Heat exchanger; 15-Four-way valve; 41-Shell; 42-Thrust block; 43-Elastic element; 411-Inlet; 422-Outlet. Detailed Implementation

[0030] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0032] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0033] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0034] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0035] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0036] The outdoor unit system of this application embodiment is applied to an air conditioning unit, specifically a multi-split air conditioning unit, a single-split air conditioning unit, etc., and is not specifically limited. For ease of understanding of the technical solution of this application, the following embodiments can all be understood as applying the outdoor unit system of this application to a multi-split air conditioning unit.

[0037] Please see Figure 1 This application provides an outdoor unit system, including: an outdoor heat exchange assembly 10, an oil separator 20, a compressor 30, an oil return check valve 40, and a gas-liquid separator 70. The outlet of the oil separator 20 is connected to the outdoor heat exchange assembly 10; the exhaust port of the compressor 30 is connected to the inlet of the oil separator 20; the inlet of the oil return check valve 40 is connected to the side outlet of the oil separator 20, and the outlet of the oil return check valve 40 is connected to the suction port of the compressor 30; wherein, under the condition of operation at a first load, the oil return check valve 40 is open, and under the condition of operation at a second load, the oil return check valve 40 is closed, and the first load is greater than the second load; the inlet of the gas-liquid separator 70 is connected to the outdoor heat exchange assembly 10, and the outlet of the gas-liquid separator 70 is connected to the suction port of the compressor 30.

[0038] Specifically, the outdoor heat exchange component 10, also known as the outdoor unit system, is the component used for heat exchange. It serves as a window for the system to release or absorb heat. In cooling mode, it acts as a condenser, discharging the heat absorbed indoors along with the heat generated by the compressor 30 to the outside. In heating mode, it acts as an evaporator, absorbing heat from the outdoor air. Its type is not unique and varies depending on the air conditioning unit; therefore, no specific definition is provided here. The oil separator 20, installed after the compressor 30's discharge port, is a container-shaped component used to separate the lubricating oil mixed in the high-pressure refrigerant gas. The compressor 30 is the mechanical device that drives the refrigerant to circulate in the system and increases its pressure and temperature. The oil return check valve 40, installed on the oil return line of the oil separator 20, allows lubricating oil to flow only in one direction (i.e., from the side outlet of the oil separator 20 to the compressor 30) and automatically opens and closes according to the load status of the outdoor unit system. The gas-liquid separator 70 is a container-shaped component installed before the suction port of the compressor 30 to separate and prevent liquid refrigerant or a large amount of lubricating oil from entering the compressor 30.

[0039] During the operation of the air conditioning unit, the higher the load, the higher the operating frequency of the compressor 30, and the more lubricating oil the compressor 30 discharges, i.e., the higher the oil discharge rate. Conversely, the lower the load, the lower the operating frequency of the compressor 30, and the less lubricating oil the compressor 30 discharges (or even none at all). Therefore, when the load of the air conditioning unit is high, it is more necessary to return oil to the compressor 30, while when the load is low, oil return may be unnecessary or only a small amount may be returned, prioritizing energy efficiency.

[0040] Therefore, in the embodiment, when the air conditioning unit is operating under a relatively high first load, the system pressure of the outdoor unit is high. Under this pressure, the oil return check valve 40 is opened, thereby realizing the oil return operation. However, when the air conditioning unit is operating under a relatively low second load, the system pressure is low. Under this pressure, the oil return check valve 40 cannot be opened, and the bypass branch for oil return is closed, thus ensuring operational efficiency.

[0041] It should be noted that the magnitude of the first load and the second load is not unique. In one embodiment, the configuration of the first load and the second load can be made by combining the pressure of the bypass branch between the bypass outlet of the oil separator 20 and the suction port of the compressor 30.

[0042] Specifically, in one embodiment, the load corresponding to the pressure that causes the return oil check valve 40 to open can be designated as the first load, and the load corresponding to the pressure that does not cause the return oil check valve 40 to open can be designated as the second load. For example, the load of the air conditioning unit with a pressure in the range of 1.2 MPa to 1.5 MPa can be designated as the first load, and the load corresponding to a pressure below 1.2 MPa can be designated as the second load. The specific configuration should be tailored to actual needs, ensuring that the pressure generated under the first load is sufficient to drive the return oil check valve 40 to open, while the pressure generated under the second load is insufficient to drive the return oil check valve 40 to open.

[0043] In the aforementioned outdoor unit system, an oil return check valve 40 is installed between the suction port of the compressor 30 and the bypass outlet of the oil separator 20. The oil return check valve 40 enables unidirectional flow from the bypass outlet of the oil separator 20 to the suction port of the compressor 30. When the air conditioning unit operates at a higher first load, the oil return check valve 40 is open, returning the lubricating oil separated by the oil separator 20 to the compressor 30. When the air conditioning unit operates at a lower second load, the oil return check valve 40 is closed, terminating the oil return operation. This design allows for oil return under high-load operating conditions by opening the oil return check valve 40, ensuring oil return to the compressor 30 when the oil discharge rate is high. Under low-load conditions, the oil return check valve 40 is closed to reduce bypass and ensure the air conditioning unit's operating efficiency. Thus, real-time oil return is unnecessary, reducing the frequency of opening the bypass branch between the oil separator 20 and the compressor 30, thereby reducing the impact of the oil separator 20 on the operating efficiency of the multi-split air conditioning unit.

[0044] Please see Figure 2 In one embodiment, the outdoor unit system further includes a first flow regulating component 50, which is connected in series between the inlet of the return oil check valve 40 and the side outlet of the oil separator 20.

[0045] Specifically, a flow regulating component is a device that can regulate the flow rate of fluid flowing through a pipeline, thereby achieving a throttling function. Through the configuration of the first flow regulating component 50, under high load conditions, the lubricating oil separated by the oil separator 20, after being throttled by the first flow regulating component 50, flows into the compressor 30 for recovery via the return oil check valve 40. In this way, the return oil can be appropriately throttled, preventing excessively abrupt return and making the return process smoother. It also provides a certain buffering and stabilizing effect on the high-pressure airflow, thus ensuring smooth oil return.

[0046] The above scheme configures a first flow regulating component 50 between the side outlet of the oil separator 20 and the inlet of the return oil check valve 40. When the return oil check valve 40 is open, it can assist in throttling and stabilize the flow, thereby improving the reliability of the return oil.

[0047] It should be noted that the type of the first flow regulating component 50 is not unique. In one embodiment, the first flow regulating component 50 is a first capillary or a first electronic expansion valve.

[0048] Specifically, a capillary tube is a device that uses its slender inner diameter and length to generate a fixed flow resistance, thereby achieving a fixed throttling function. An electronic expansion valve, on the other hand, uses a stepper motor to control the opening of the valve needle, thus precisely regulating the fluid flow rate. In practical applications, either a capillary tube or an electronic expansion valve can be selected as the first flow regulation component 50, depending on the requirements; no specific limitation is made here.

[0049] The above solution uses a capillary tube or electronic expansion valve as the first flow regulating component 50, which has a simple structure and is easy to implement, effectively saving hardware costs and improving installation convenience.

[0050] Please see Figure 3 In one embodiment, the outdoor unit system further includes a second flow regulating component 60, the first end of which is connected to the inlet of the return oil check valve 40 and the first flow regulating component 50, and the second end of which is connected to the outlet of the return oil check valve 40.

[0051] Specifically, in this embodiment, a second flow regulating component 60 is connected in parallel at the oil return check valve 40. Thus, even when the air conditioning unit operates at a low load, it ensures that the bypass outlet of the oil separator 20 is connected to the compressor 30 via the first flow regulating component 50 and the second flow regulating component 60. In low-temperature scenarios (such as below -35 degrees Celsius), the outdoor unit system still has a certain amount of oil return. In high-load scenarios, oil return can be achieved through two branches: the first flow regulating component 50-the second flow regulating component 60, and the first flow regulating component 50-the oil return check valve 40, further improving oil return efficiency.

[0052] It should be noted that the flow rates of the first flow regulating component 50 and the second flow regulating component 60 should be set to a relatively small value to ensure that there is no significant leakage, which could have an excessive impact on the energy efficiency of the outdoor unit in low-temperature or low-load scenarios.

[0053] In the above solution, a second flow regulating component 60 is connected in parallel across both ends of the return oil check valve 40. This allows for the opening of a single branch in low-temperature scenarios to ensure a certain amount of return oil without causing excessive leakage. Simultaneously, in heavy-load scenarios, both branches can be opened for oil return and pressure relief, improving the operational reliability of the outdoor unit system.

[0054] Similarly, the type of the second flow regulating component 60 is not unique; in one embodiment, the second flow regulating component 60 is a second capillary or a second electronic expansion valve.

[0055] Specifically, in actual scenarios, the first flow regulation component 50 and the second flow regulation component 60 can be of the same type or different types. There are no specific restrictions, and the choice can be made based on actual needs.

[0056] The above solution uses a capillary tube or electronic expansion valve as the second flow regulating component 60, which has a simple structure and is easy to implement, effectively saving hardware costs and improving installation convenience.

[0057] It is understood that, in one embodiment, the outlet of the return oil check valve 40 and the suction port of the compressor 30 may be configured with only the return oil check valve 40 and the second flow regulating component 60 connected in parallel. This allows for lower hardware costs while ensuring that the outdoor unit system maintains a certain return flow rate in low-temperature scenarios and that, under high-load scenarios, oil return occurs simultaneously through two branches, ensuring oil return efficiency.

[0058] In one embodiment, the second flow regulating component 60 includes a third capillary and a switching element. The first end of the third capillary is connected to the first end of the switching element, the second end of the switching element is connected to the inlet of the return oil check valve 40 and the first flow regulating component 50, and the second end of the third capillary is connected to the outlet of the return oil check valve 40.

[0059] Specifically, the switching element, which controls the connection or disconnection of the second flow regulating valve to the inlet of the return oil check valve 40, is not unique and can be a solenoid valve, etc., without limitation. In this embodiment, the second flow regulating component 60 is constructed in series with the third capillary tube and the switching element. Thus, the second flow regulating component 60 can be connected and disconnected according to actual needs.

[0060] In the above scheme, the second flow regulating component 60 includes a third capillary tube and a switching element. The third capillary tube can be connected or disconnected under the control of the switching element according to actual needs, so as to realize the controllable shutdown of the parallel branch and improve the controllability of oil return.

[0061] Please see Figure 4 In one embodiment, the return oil check valve 40 includes a housing 41, a thrust block 42, and an elastic element 43. The housing 41 has a communicating inlet 411 and an outlet 422. The first end of the thrust block 42 is disposed at the inlet 411 of the housing 41, and the second end of the thrust block 42 is connected to the elastic element 43. The elastic element 43 is fixedly disposed inside the housing 41.

[0062] Specifically, the housing 41 is the main external structure of the one-way valve, a hollow, usually tubular metal or plastic component that forms the channel for the flow of refrigerant and lubricating oil. The thrust block 42 is installed inside the housing 41 and can move within a certain range by pressing the elastic element 43, thus opening or closing the flow channel.

[0063] It is understood that, in one embodiment, in order to ensure that the thrust block 42 can completely block the inlet 411 and control the on / off state, the area of ​​the end of the thrust block 42 near the inlet 411 needs to be set to be greater than or equal to the cross-sectional area of ​​the inlet.

[0064] The shape of the thrust block 42 is not unique and can be adapted to the inlet configuration, partially inserted into the inlet 411 during sealing. It can also be set to other shapes, and there is no specific limitation. The type of elastic element 43 is not unique. It can be a spring or other, as long as it can deform under pressure and recover its deformation when the pressure decreases or disappears.

[0065] The above solution uses a housing 41, a thrust block 42, and an elastic element 43 to form a return oil check valve 40. The thrust block 42 is pushed by overcoming the resistance of the elastic element 43, thereby achieving unidirectional flow control. In this way, adaptive on / off switching can be achieved with a simple structure, without the need for additional control signals, thus balancing energy efficiency and oil return.

[0066] Please refer to the following: Figures 1-3 In one embodiment, the outdoor heat exchange assembly 10 includes a plate heat exchanger 11, a heat exchanger 14, a third electronic expansion valve 12, a fourth electronic expansion valve 13, and a four-way valve 15. The first end of the plate heat exchanger 11 is connected to the indoor unit system via a liquid pipe. The second end of the plate heat exchanger 11 is connected to the first end of the third electronic expansion valve 12 and the first end of the fourth electronic expansion valve 13. The second end of the third electronic expansion valve 12 is connected to the third end of the plate heat exchanger 11. The fourth end of the plate heat exchanger 11 is connected to the compressor 30. The second end of the fourth electronic expansion valve 13 is connected to the heat exchanger 14. The heat exchanger 14 is connected to the first end of the four-way valve 15. The second end of the four-way valve 15 is connected to the outlet of the oil separator 20. The third end of the four-way valve 15 is connected to the inlet of the gas-liquid separator 70. The fourth end of the four-way valve 15 is connected to the indoor unit system via a gas pipe.

[0067] Specifically, the plate heat exchanger 11, which is also the performance enhancer of the outdoor unit system, has its fourth end connected to the enthalpy booster port of the compressor 30 to send medium-pressure gas back to the compressor 30. The heat exchanger 14 is the main heat exchanger, acting as a condenser during cooling and an evaporator during heating. The four-way valve 15 switches the refrigerant flow direction by changing its internal flow path, thereby achieving the conversion between cooling and heating modes.

[0068] Taking the heating mode as an example, the compressor 30 compresses the refrigerant into a high-temperature, high-pressure gas. After passing through the oil separator 20, most of the gas enters the four-way valve 15, and flows through the four-way valve 15 and the gas pipe to the indoor unit system for heat release and condensation. The high-pressure liquid condensed in the indoor unit returns to the outdoor unit system through the liquid pipe, enters the plate heat exchanger 11 and the heat exchanger 14 for processing, and then flows back to the compressor 30.

[0069] The above scheme, in which the outdoor heat exchange component 10 is constructed by plate heat exchanger 11, heat exchanger 14, third electronic expansion valve 12, fourth electronic expansion valve 13 and four-way valve 15, has the advantages of high energy efficiency in cooling or heating, good economy and high operating energy efficiency.

[0070] This application also provides an air conditioning unit, including an indoor unit system and the aforementioned outdoor unit system.

[0071] Specifically, the structure and implementation of the indoor unit system are as shown in the above embodiments and accompanying drawings, and will not be repeated here. In the above-mentioned air conditioning unit, an oil return check valve 40 is installed between the suction port of the compressor 30 and the bypass outlet of the oil separator 20 in the outdoor unit system. The oil return check valve 40 enables unidirectional flow from the bypass outlet of the oil separator 20 to the suction port of the compressor 30. When the air conditioning unit operates at a higher first load, the oil return check valve 40 is open, delivering the lubricating oil separated by the oil separator 20 back to the compressor 30; when the air conditioning unit operates at a lower second load, the oil return check valve 40 is closed, terminating the oil return operation. This scheme allows for oil return by opening the oil return check valve 40 during high-load operation, ensuring oil return to the compressor 30 when the oil discharge rate is high; and by closing the oil return check valve 40 during low-load operation, reducing bypass and ensuring the operating efficiency of the air conditioning unit. In this way, there is no need for real-time oil return, reducing the frequency of opening the bypass branch between the oil separator 20 and the compressor 30, thereby reducing the impact of the oil separator 20 on the operating energy efficiency of the multi-split air conditioning unit.

[0072] In one embodiment, the air conditioning unit is a multi-split air conditioning unit.

[0073] Specifically, a multi-split air conditioning unit also consists of an outdoor unit system connected to multiple indoor unit systems, or multiple outdoor unit systems connected to multiple indoor unit systems. In this embodiment, the aforementioned outdoor unit system is used in a multi-split air conditioning unit. Therefore, an oil return check valve 40 can be configured between the bypass outlet of the oil separator 20 and the suction port of the compressor 30 in the multi-split air conditioning unit. This ensures oil return to the multi-split air conditioning unit while reducing the impact of the bypass branch on the energy efficiency of the multi-split air conditioning unit.

[0074] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0075] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An outdoor unit system, characterized in that, include: Outdoor heat exchange components; An oil separator, the outlet of which is connected to the outdoor heat exchange assembly; A compressor, the discharge port of which is connected to the inlet of the oil separator; An oil return check valve is provided, with its inlet connected to the side outlet of the oil separator and its outlet connected to the suction port of the compressor. The oil return check valve is open when operating at a first load and closed when operating at a second load, wherein the first load is greater than the second load. A gas-liquid separator, the inlet of which is connected to the outdoor heat exchange assembly, and the outlet of which is connected to the suction port of the compressor.

2. The outdoor unit system according to claim 1, characterized in that, The outdoor unit system also includes a first flow regulating component, which is connected in series between the inlet of the oil return check valve and the side outlet of the oil separator.

3. The outdoor unit system according to claim 2, characterized in that, The first flow regulating component is a first capillary tube or a first electronic expansion valve.

4. The outdoor unit system according to claim 2, characterized in that, The outdoor unit system also includes a second flow regulating component. The first end of the second flow regulating component is connected to the inlet of the return oil check valve and the first flow regulating component, and the second end of the second flow regulating component is connected to the outlet of the return oil check valve.

5. The outdoor unit system according to claim 4, characterized in that, The second flow regulating component is a second capillary tube or a second electronic expansion valve.

6. The outdoor unit system according to claim 4, characterized in that, The second flow regulating component includes a third capillary tube and a switching element. The first end of the third capillary tube is connected to the first end of the switching element, the second end of the switching element is connected to the inlet of the return oil check valve and the first flow regulating component, and the second end of the third capillary tube is connected to the outlet of the return oil check valve.

7. The outdoor unit system according to any one of claims 1-6, characterized in that, The return oil check valve includes a housing, a thrust block, and an elastic element. The housing has a communicating inlet and outlet. The first end of the thrust block is located at the inlet of the housing, and the second end of the thrust block is connected to the elastic element. The elastic element is fixedly located inside the housing.

8. The outdoor unit system according to any one of claims 1-6, characterized in that, The outdoor heat exchange assembly includes a plate heat exchanger, a heat exchanger, a third electronic expansion valve, a fourth electronic expansion valve, and a four-way valve. The first end of the plate heat exchanger is connected to the indoor unit system via a liquid pipe. The second end of the plate heat exchanger is connected to the first ends of the third and fourth electronic expansion valves. The second end of the third electronic expansion valve is connected to the third end of the plate heat exchanger. The fourth end of the plate heat exchanger is connected to the compressor. The second end of the fourth electronic expansion valve is connected to the heat exchanger. The heat exchanger is connected to the first end of the four-way valve. The second end of the four-way valve is connected to the outlet of the oil separator. The third end of the four-way valve is connected to the inlet of the gas-liquid separator. The fourth end of the four-way valve is connected to the indoor unit system via a gas pipe.

9. An air conditioning unit, characterized in that, It includes an indoor unit system and an outdoor unit system as described in any one of claims 1-8.

10. The air conditioning unit according to claim 9, characterized in that, The air conditioning unit is a multi-split air conditioning unit.

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