Air conditioner

Abstract

The utility model discloses an air conditioner which comprises a refrigerating system and an oil separator, wherein the refrigerating system consists of a compressor, a first heat exchanger, a second heat exchanger and a throttling device; the oil separator is located between the compressor and the first heat exchanger and comprises an air inlet, an air outlet and an oil outlet. The air inlet is connected with an exhaust port of the compressor; the air outlet is connected with one end of the first heat exchanger; the compressor is variable in load; the air conditioner further comprises a first oil return pipeline and a second electromagnetic valve. The first oil return pipeline comprises a first electromagnetic valve and a first capillary tube which are connected in series, two ends of the first oil return pipeline are respectively connected with the oil outlet and an air suction port of the compressor, and the first oil return pipeline is used for communicating return oil during high load; the two ends of the second electromagnetic valve are connected with the oil outlet and the air outlet correspondingly, and the second electromagnetic valve is used for communicating in the low load so that lubricating oil can return to the refrigerating system for circulating oil return. Different oil return modes are selected according to the operation load of the compressor, and the energy efficiency during low-load operation is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of air conditioning, in particular to an air conditioner. Background Art

[0002] When the air conditioner compressor is running, a certain amount of lubricating oil will be brought into the refrigeration system. At the same time, part of the lubricating oil will be driven by the high-speed flowing refrigerant to return to the compressor from the air intake. When the amount of discharged oil is equal to the amount of returned oil, the compressor reaches oil balance, the oil in the oil pool will not decrease, and it can operate safely. When the discharged oil is more than the returned oil, the compressor will be empty of oil, affecting its safe and stable operation.

[0003] For compressors with variable loads, the exhaust flow rate is usually high at high loads, which makes it easy for oil to be exhausted, but it will not be exhausted at low loads. In order to ensure the safe operation of the compressor, an external oil separator and an oil return pipeline are designed for it. The discharged lubricating oil is intercepted by the external oil separator and directly returned to the suction port of the compressor through the oil return pipe to avoid oil exhaust. The addition of oil separators and oil return pipes ensures that there is no oil exhaust, but it also causes negative effects. Because the high-temperature lubricating oil returned to the suction port of the compressor will increase the suction superheat and suction specific volume, and reduce the cooling capacity and efficiency of the compressor.

[0004] At present, the industry usually chooses to ignore the impact on performance in order to ensure the safety of compressor oil return. In actual operation, the efficiency of the unit will drop significantly within the full load range of the compressor. In fact, the compressor oil shortage mainly occurs at high load. At low load, the compressor exhaust volume is reduced, and the amount of lubricating oil carried out is limited, so there will be no oil shortage problem. Even without an external oil separator and oil return pipe, the safe operation of the compressor can be guaranteed. However, as long as the oil separator and oil return pipe are set, the oil return valve needs to be kept open at low load, otherwise the oil stored in the oil separator will not return to the second channel in the system, and will accumulate more and more, eventually causing the compressor to be oil-free. The current technical status is that different oil return pipelines and control methods are not designed according to the different load sections of the compressor. Generally speaking, oil return is also carried out in the load section where oil return is not required, resulting in an unnecessary decrease in the unit's energy efficiency.

[0005] The above information disclosed in the background technology is only used to increase the understanding of the background technology of the present application, and therefore, it may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] In view of the problem of reduced energy efficiency of the unit during low-load operation caused by a single oil return method of a variable load compressor system proposed in the background technology, the utility model proposes an air conditioner that selects different oil return methods according to the operating load to improve the energy efficiency during low-load operation.

[0007] In order to achieve the above-mentioned utility model purpose, the utility model adopts the following technical solutions:

[0008] An air conditioner comprises a compressor, a first heat exchanger, a second heat exchanger, a throttling device, and an oil separator; the compressor, the first heat exchanger, the throttling device, and the second heat exchanger are connected to form a refrigeration system; the oil separator is located between the compressor and the first heat exchanger, and comprises an air inlet, an air outlet, and an oil outlet; the air inlet is connected to the exhaust port of the compressor; the air outlet is connected to one end of the first heat exchanger; the compressor is a variable load compressor;

[0009] It also includes a first oil return pipeline and a second solenoid valve;

[0010] The first oil return pipeline comprises a first solenoid valve and a first capillary tube connected in series, and both ends are respectively connected to the oil outlet and the air intake of the compressor, and when connected, is used for oil return when the compressor is running at high load;

[0011] The two ends of the second solenoid valve are respectively connected to the oil outlet and the air outlet; when connected, the lubricating oil in the oil separator returns to the refrigeration system and circulates back the oil when the compressor is running at a low load.

[0012] In a specific embodiment, the air conditioner also includes a second oil return pipeline, which includes a third solenoid valve and a second capillary connected in series; the oil outlet is connected to the air intake port through the second oil return pipeline; the second capillary has the same inner diameter as the first capillary, and its length is greater than the length of the first capillary.

[0013] In a specific embodiment, the air conditioner also includes a second oil return pipeline, which includes a third solenoid valve and a second capillary connected in series; the oil outlet is connected to the air intake port through the second oil return pipeline; the second capillary has the same length as the first capillary, and an inner diameter is smaller than the inner diameter of the first capillary.

[0014] In some specific embodiments, the compressor is a variable frequency compressor, a screw compressor, or a centrifugal compressor.

[0015] In some specific embodiments, a four-way valve is further included, which includes a first port, a second port, a third port, and a fourth port; the first port is connected to the air outlet; the second port is connected to one end of the first heat exchanger; the third port is connected to the air intake port; and the fourth port is connected to one end of the second heat exchanger.

[0016] In some specific embodiments, a gas-liquid separator is further included, which includes an inlet and an outlet; the third port is connected to the inlet; and the outlet is connected to the air intake port.

[0017] An air conditioner comprises a compressor, a first heat exchanger, a second heat exchanger, a throttling device, and an oil separator; the compressor, the first heat exchanger, the throttling device, and the second heat exchanger are connected to form a refrigeration system; the oil separator is located between the compressor and the first heat exchanger, and comprises an air inlet, an air outlet, and an oil outlet; the air inlet is connected to the exhaust port of the compressor; the air outlet is connected to one end of the first heat exchanger; the compressor is a variable load compressor;

[0018] Also includes a first solenoid valve and a second solenoid valve;

[0019] The two ends of the first solenoid valve are respectively connected to the oil outlet and the air intake of the compressor through a refrigerant pipe, and when connected at different duty ratios, they are used for returning oil when the compressor is running at different loads;

[0020] The second solenoid valve is connected to the refrigerant pipeline to form a bypass pipeline; the two ends of the bypass pipeline are respectively connected to the oil outlet and the air outlet; when connected, the lubricating oil in the oil separator returns to the refrigeration system and follows the refrigeration cycle to return oil when the compressor is running at low load.

[0021] In a specific embodiment, the air conditioner also includes a four-way valve, which includes a first port, a second port, a third port, and a fourth port; the first port is connected to the air outlet; the second port is connected to one end of the first heat exchanger; the third port is connected to the air intake port; and the fourth port is connected to one end of the second heat exchanger.

[0022] In a specific embodiment, the air conditioner further includes a gas-liquid separator, which includes an inlet and an outlet; the third port is connected to the inlet; and the outlet is connected to the air intake port.

[0023] In some specific embodiments, the compressor is a variable frequency compressor, a screw compressor, or a centrifugal compressor.

[0024] The air conditioner of the utility model is provided with a first oil return pipeline including a first solenoid valve and a bypass pipeline composed of a second solenoid valve to realize the selection of returning oil through the first oil return pipeline or returning the lubricating oil in the oil separator to the refrigeration cycle system and following the refrigeration cycle oil return according to the operating load of the compressor, so that oil exhaust will not occur when the air conditioner is operated at high load, thereby improving the safety and reliability of the operation of the air conditioner; when operating at low load, the influence of high-temperature lubricating oil on the suction superheat and suction specific volume is avoided, thereby improving the cooling capacity and efficiency at low load.

[0025] After reading the specific embodiments of the present invention in conjunction with the accompanying drawings, other features and advantages of the present invention will become more clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0027] Figure 1 is a structural schematic diagram of an air conditioner according to an embodiment;

[0028] Figure 2 is a structural schematic diagram of an air conditioner according to an embodiment;

[0029] Figure 3 is a structural schematic diagram of an air conditioner according to an embodiment;

[0030] Figure 4 is a structural schematic diagram of an air conditioner according to an embodiment;

[0031] Figure 5 is a structural schematic diagram of an air conditioner according to an embodiment;

[0032] Figure 6 is a structural schematic diagram of an air conditioner according to an embodiment;

[0033] Figure 7 is a structural schematic diagram of an air conditioner according to an embodiment;

[0034] Figure 8 is a structural schematic diagram of an air conditioner according to an embodiment;

[0035] Fig. 9 is a structural schematic diagram of an air conditioner according to an embodiment;

[0036] Fig.10 Schematic diagram of the structure of an air conditioner according to an embodiment.

[0037] Reference numerals,

[0038] 1. Compressor; 2. First heat exchanger; 3. Second heat exchanger; 4. Throttling device; 5. Oil separator; 6. First solenoid valve; 7. First capillary tube; 8. Second solenoid valve; 9. Four-way valve; 10. Gas-liquid separator; 20. Third solenoid valve; 30. Second capillary tube; 40. Electronic expansion valve. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0041] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0042] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0043] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0044] The disclosure below provides many different embodiments or examples for realizing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the utility model. In addition, the utility model may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the utility model provides various specific examples of processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0045]

Principle of air conditioner

[0046] The air conditioner performs the air conditioner's refrigeration cycle by using a compressor, condenser, expansion valve, and evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation to cool or heat the indoor space.

[0047] The low-temperature and low-pressure refrigerant enters the compressor, which compresses it into high-temperature and high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0048] The expansion valve expands the high-temperature and high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant expanded in the expansion valve and returns the low-temperature and low-pressure refrigerant gas to the compressor. The evaporator can achieve a cooling effect by utilizing the latent heat of evaporation of the refrigerant to exchange heat with the material to be cooled. In the entire cycle, the air conditioner can adjust the temperature of the indoor space.

[0049] The outdoor unit of the air conditioner refers to a portion of a refrigeration cycle including a compressor and an outdoor heat exchanger, the indoor unit of the air conditioner includes an indoor heat exchanger, and an expansion valve may be provided in the indoor unit or the outdoor unit.

[0050] The indoor heat exchanger and the outdoor heat exchanger function as a condenser or an evaporator. When the indoor heat exchanger functions as a condenser, the air conditioner functions as a heater in a heating mode, and when the indoor heat exchanger functions as an evaporator, the air conditioner functions as a cooler in a cooling mode.

[0051]

This application

[0052] Reference Figure 1The utility model discloses an air conditioner, which includes a compressor 1, a first heat exchanger 2, a second heat exchanger 3, a second heat exchanger 3, and an oil separator 5. The compressor 1, the first heat exchanger 2, the second heat exchanger 3, and the second heat exchanger 3 are connected in sequence to form a ring to form a refrigeration system. The oil separator 5 is located between the compressor 1 and the first heat exchanger 2, and includes an air inlet, an air outlet, and an oil outlet. The air inlet is connected to the exhaust port of the compressor 1; the high-temperature and high-pressure refrigerant gas discharged by the compressor 1 enters the oil separator 5 from the air inlet. The air outlet is connected to one end of the first heat exchanger 2; the oil separator 5 filters the lubricating oil of the high-temperature and high-pressure gas refrigerant and then discharges it from the air outlet and transmits it to the first heat exchanger 2 through the refrigerant pipe; the first heat exchanger 2 acts as a condenser to dissipate heat from the high-temperature and high-pressure refrigerant gas.

[0053] The compressor 1 is a variable load compressor 1, such as a variable frequency compressor 1, a screw compressor 1, a centrifugal compressor 1, etc.

[0054] The air conditioner also includes a first oil return pipeline, which includes a first solenoid valve 6 and a first capillary tube 7 connected in series through a refrigerant pipe; wherein the first solenoid valve 6 is used to control the on-off of the first oil return pipeline; the first capillary tube 7 is used to dissipate heat and reduce the pressure of the medium passing through it; the oil outlet is connected to the air intake port of the compressor 1 through the first oil return pipeline, that is, the two ends of the first oil return pipeline are respectively connected to the oil outlet and the air intake port; when the first solenoid valve 6 is connected, the lubricating oil in the oil separator 5 when the compressor 1 is in high-load operation is directly returned to the air intake port; the first capillary tube 7 is used to reduce the pressure and cool the lubricating oil passing through it.

[0055] The air conditioner also includes a second solenoid valve 8, both ends of which are connected to the oil outlet and the air outlet respectively through refrigerant pipes; when connected, the lubricating oil in the oil separator 5 enters the refrigeration system from the oil outlet through the bypass pipeline where the second solenoid valve 8 is located when the compressor 1 is running at low load, and returns to the compressor 1 from the air intake port after the refrigeration cycle.

[0056] Specifically, when the compressor 1 is running at high load, the first solenoid valve 6 is connected and the second solenoid valve 8 is closed; the lubricating oil in the oil separator 5 is directly returned to the air intake port through the first oil return pipeline. When the compressor 1 is running at low load, the first solenoid valve 6 is closed and the second solenoid valve 8 is connected; the lubricating oil blocked by the oil separator 5 returns to the refrigeration system through the oil outlet through the second solenoid valve 8 and enters the first heat exchanger 2 along with the gas refrigerant coming out of the air outlet, and follows the refrigerant through the first heat exchanger 2, the second heat exchanger 3, and the second heat exchanger 3, and returns to the compressor 1 from the air intake port.

[0057] The air conditioner of the utility model is provided with a first oil return pipeline including a first solenoid valve 6 and a bypass pipeline composed of a second solenoid valve 8 to realize the selection of returning oil through the first oil return pipeline or returning the lubricating oil in the oil separator 5 to the refrigeration cycle system and following the refrigeration cycle oil return according to the operating load of the compressor 1, so that oil exhaust will not occur when the air conditioner is operated at high load, thereby improving the safety and reliability of the operation of the air conditioner; when operating at low load, the influence of high-temperature lubricating oil on the suction superheat and suction specific volume is avoided, thereby improving the cooling capacity and efficiency at low load.

[0058] The connection or cutoff of the first electromagnetic valve 6 and the second electromagnetic valve 8 can be realized by mechanical linkage with a set pressure or set temperature sensor provided in the system, or can be realized by a controller connected thereto according to the operating load control of the compressor 1.

[0059] In some specific embodiments, reference Figure 2 , also includes a four-way valve 9, which includes a first port, a second port, a third port, and a fourth port; the first port is connected to the air outlet; the second port is connected to one end of the first heat exchanger 2; the third port is connected to the air intake port; and the fourth port is connected to one end of the second heat exchanger 3.

[0060] During cooling, the first port of the four-way valve 9 is connected to the second port, and the third port is connected to the fourth port; and when the load is low, the lubricating oil returned to the refrigeration system from the oil outlet through the second solenoid valve 8 through the four-way valve 9, the first heat exchanger 2, the second heat exchanger 3, and the second heat exchanger 3 returns to the compressor 1.

[0061] During heating, the first port of the four-way valve 9 is connected to the fourth port, and the second port is connected to the third port; and when the load is low, the lubricating oil returned to the heating system from the oil outlet through the second solenoid valve 8, and then returns to the compressor 1 through the four-way valve 9, the second heat exchanger 3, the second heat exchanger 3, and the first heat exchanger 2.

[0062] In a specific embodiment, referring to Figure 3 The air conditioner includes a compressor 1, a first heat exchanger 2, a second heat exchanger 3, a second heat exchanger 3, and an oil separator 5. The compressor 1, the first heat exchanger 2, the second heat exchanger 3, and the second heat exchanger 3 are connected in sequence to form a ring to form a refrigeration system. The oil separator 5 is located between the compressor 1 and the first heat exchanger 2, and includes an air inlet, an air outlet, and an oil outlet. The air inlet is connected to the exhaust port of the compressor 1; the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 enters the oil separator 5 from the air inlet. The air outlet is connected to one end of the first heat exchanger 2; the oil separator 5 filters the lubricating oil of the high-temperature and high-pressure gas refrigerant and then discharges it from the air outlet and transmits it to the first heat exchanger 2 through the refrigerant pipe; the first heat exchanger 2 acts as a condenser to dissipate the heat of the high-temperature and high-pressure refrigerant gas.

[0063] The compressor 1 is a variable load compressor 1, such as a variable frequency compressor 1, a screw compressor 1, a centrifugal compressor 1, etc.

[0064] The air conditioner also includes a first oil return pipeline, which includes a first solenoid valve 6 and a first capillary tube 7 connected in series through a refrigerant pipe; wherein the first solenoid valve 6 is used to control the on-off of the first oil return pipeline; the first capillary tube 7 is used to dissipate heat and reduce the pressure of the medium passing through it; the oil outlet is connected to the air intake port of the compressor 1 through the first oil return pipeline, that is, the two ends of the first oil return pipeline are respectively connected to the oil outlet and the air intake port; when the first solenoid valve 6 is connected, the lubricating oil in the oil separator 5 when the compressor 1 is in high-load operation is directly returned to the air intake port; the first capillary tube 7 is used to reduce the pressure and cool the lubricating oil passing through it.

[0065] The air conditioner also includes a second oil return pipeline, which includes a third solenoid valve 20 and a second capillary tube 30 connected in series through a refrigerant pipe; wherein the third solenoid valve 20 is used to control the on-off of the second oil return pipeline; the second capillary tube 30 is used to dissipate heat and reduce the pressure of the medium passing through it; the oil outlet is connected to the air intake port of the compressor 1 through the second oil return pipeline, that is, the two ends of the second oil return pipeline are respectively connected to the oil outlet and the air intake port; the inner diameter of the first capillary tube 7 is the same as the inner diameter of the second capillary tube 30; the length of the second capillary tube 30 is greater than the length of the first capillary tube 7.

[0066] The second oil return pipeline is used for returning the lubricating oil in the oil separator 5 directly to the suction port when the compressor 1 is operating at a slightly lower load; it is adapted to a smaller amount of returned oil, improves the pressure reduction and cooling effect of the lubricating oil when passing through the second capillary tube 30, reduces the influence of the high temperature of the returned oil on the suction superheat and suction specific volume, and improves the cooling capacity and efficiency of the air conditioner.

[0067] The air conditioner also includes a second solenoid valve 8, both ends of which are connected to the oil outlet and the air outlet respectively through refrigerant pipes; when the compressor 1 is running at low load, the lubricating oil in the oil separator 5 enters the refrigeration system from the oil outlet through the bypass pipeline where the second solenoid valve 8 is located, and returns to the air intake port for oil return through the refrigeration cycle.

[0068] The slightly lower load mentioned above is lower than the high load suitable for oil return through the first oil return pipeline, and higher than the low load suitable for oil return through the bypass pipeline. The air conditioner of this embodiment adds a second oil return pipeline suitable for oil return under intermediate load, thereby improving the load operating range of the compressor 1 and its safety and reliability during operation.

[0069] Specifically, when the compressor 1 is operating at a high load, the first solenoid valve 6 is connected, the second solenoid valve 8 and the third solenoid valve 20 are cut off, and the oil is directly returned through the first return oil pipeline; when the compressor 1 is operating at a slightly lower load, the first solenoid valve 6 and the second solenoid valve 8 are cut off, the third solenoid valve 20 is connected, and the oil is directly returned through the second return oil pipeline; when the compressor 1 is operating at a low load, the first solenoid valve 6 and the third solenoid valve 20 are cut off, and the second solenoid valve 8 is connected, and the lubricating oil in the oil separator 5 returns to the refrigeration system through the second solenoid valve 8, and the oil is circulated back with the refrigeration system; that is, the lubricating oil blocked by the oil separator 5 returns to the refrigeration system from the oil outlet through the second solenoid valve 8 and enters the first heat exchanger 2 with the gas refrigerant coming out of the air outlet, and follows the refrigerant through the first heat exchanger 2, the second heat exchanger 3, and the second heat exchanger 3, and returns to the compressor 1 from the air intake port.

[0070] The air conditioner of the utility model realizes the selection of the first oil return pipeline, the second oil return pipeline or the bypass pipeline for oil return according to the operating load of the compressor 1 by arranging a first oil return pipeline including a first solenoid valve 6, a second oil return pipeline including a third solenoid valve 20 and a bypass pipeline whose on / off is controlled by the second solenoid valve 8, so that the return oil amount can adapt to the demand of the operating load of the compressor 1, and the influence of the high temperature of the return oil on the suction superheat and the suction specific volume can be reduced when the load is slightly low, and the influence of the high temperature of the return oil on the suction superheat and the suction specific volume can be avoided when the load is low, thereby improving the cooling capacity and efficiency when operating at slightly low load and low load.

[0071] In a specific embodiment, referring to Figure 4 On the basis of the previous embodiment, the air conditioner also includes a four-way valve 9, which includes a first port, a second port, a third port, and a fourth port; the first port is connected to the air outlet; the second port is connected to one end of the first heat exchanger 2; the third port is connected to the air intake port; and the fourth port is connected to one end of the second heat exchanger 3.

[0072] During cooling, the first port of the four-way valve 9 is connected to the second port, and the third port is connected to the fourth port; and when the load is low, the lubricating oil returned to the refrigeration system from the oil outlet through the second solenoid valve 8 through the four-way valve 9, the first heat exchanger 2, the second heat exchanger 3, and the second heat exchanger 3 returns to the compressor 1.

[0073] During heating, the first port of the four-way valve 9 is connected to the fourth port, and the second port is connected to the third port; and when the load is low, the lubricating oil returned to the heating system from the oil outlet through the second solenoid valve 8, and then returns to the compressor 1 through the four-way valve 9, the second heat exchanger 3, the second heat exchanger 3, and the first heat exchanger 2.

[0074] In a specific embodiment, referring to Figure 5The air conditioner includes a compressor 1, a first heat exchanger 2, a second heat exchanger 3, a second heat exchanger 3, and an oil separator 5. The compressor 1, the first heat exchanger 2, the second heat exchanger 3, and the second heat exchanger 3 are connected in sequence to form a ring to form a refrigeration system. The oil separator 5 is located between the compressor 1 and the first heat exchanger 2, and includes an air inlet, an air outlet, and an oil outlet. The air inlet is connected to the exhaust port of the compressor 1; the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 enters the oil separator 5 from the air inlet. The air outlet is connected to one end of the first heat exchanger 2; the oil separator 5 filters the lubricating oil of the high-temperature and high-pressure gas refrigerant and discharges it from the air outlet and transmits it to the first heat exchanger 2 through the refrigerant pipe; the first heat exchanger 2 acts as a condenser to dissipate the heat of the high-temperature and high-pressure refrigerant gas.

[0075] The compressor 1 is a variable load compressor 1, such as a variable frequency compressor 1, a screw compressor 1, a centrifugal compressor 1, etc.

[0076] The air conditioner also includes a first solenoid valve 6, whose two ends are respectively connected to the oil outlet and the air intake port. When connected or cut off, the oil outlet and the air intake port are connected or disconnected, and the duration of the connection between the oil outlet and the air intake port is controlled by changing the duty ratio of the pulse signal that controls the connection and cutoff of the first solenoid valve 6 to adapt to the size of the operating load of the compressor 1.

[0077] The duty cycle control of the first electromagnetic valve 6 can be realized by linking the pulse generator with the pressure or temperature detection unit with different set values, or can also be realized by configuring a controller connected to the first electromagnetic valve 6 according to the operating load of the compressor 1.

[0078] The air conditioner also includes a second solenoid valve 8, both ends of which are connected to the oil outlet and the air outlet respectively through refrigerant pipes; when the compressor 1 is running at low load, the lubricating oil in the oil separator 5 enters the refrigeration system through the bypass pipeline where the second solenoid valve 8 is located, and returns the oil through the refrigeration cycle.

[0079] Specifically, when the compressor 1 is operating at high or medium load, the second solenoid valve 8 is cut off, and the operation of the compressor 1 with different loads is adapted by controlling the connection of different duty ratios of the first solenoid valve 6; when the compressor 1 is operating at low load, the first solenoid valve 6 is cut off and the second solenoid valve 8 is connected, and the lubricating oil in the oil separator 5 returns to the refrigeration system through the second solenoid valve 8, and circulates back with the refrigeration system; that is, the lubricating oil blocked by the oil separator 5 returns to the refrigeration system from the oil outlet through the second solenoid valve 8 and enters the first heat exchanger 2 with the gas refrigerant coming out of the air outlet, and follows the refrigerant through the first heat exchanger 2, the second heat exchanger 3, and the second heat exchanger 3, and returns to the compressor 1 from the air intake port.

[0080] The air conditioner of the utility model is provided with a first solenoid valve 6 to connect the oil outlet and the air intake port, and a second solenoid valve 8 to connect the oil outlet and the air outlet; the duty ratio of the pulse signal of the first solenoid valve 6 is adjusted to control the amount and speed of the oil return through the first solenoid valve 6, so as to meet the high and medium load operation requirements of the compressor 1; when the load is low, the lubricating oil in the oil separator 5 is returned to the system by controlling the second solenoid valve 8 to follow the system circulation back to the compressor 1, so as to avoid its influence on the suction superheat and improve the efficiency of the compressor 1 when the load is low.

[0081] In a specific embodiment, referring to Figure 6 On the basis of the previous embodiment, the air conditioner also includes a four-way valve 9, which includes a first port, a second port, a third port, and a fourth port; the first port is connected to the air outlet; the second port is connected to one end of the first heat exchanger 2; the third port is connected to the air intake port; and the fourth port is connected to one end of the second heat exchanger 3.

[0082] During cooling, the first port of the four-way valve 9 is connected to the second port, and the third port is connected to the fourth port; and when the load is low, the lubricating oil returned to the refrigeration system from the oil outlet through the second solenoid valve 8 through the four-way valve 9, the first heat exchanger 2, the second heat exchanger 3, and the second heat exchanger 3 returns to the compressor 1.

[0083] During heating, the first port of the four-way valve 9 is connected to the fourth port, and the second port is connected to the third port; and when the load is low, the lubricating oil returned to the heating system from the oil outlet through the second solenoid valve 8, and then returns to the compressor 1 through the four-way valve 9, the second heat exchanger 3, the second heat exchanger 3, and the first heat exchanger 2.

[0084] In a specific embodiment, referring to Figure 7 The air conditioner includes a compressor 1, a first heat exchanger 2, a second heat exchanger 3, a second heat exchanger 3, and an oil separator 5. The compressor 1, the first heat exchanger 2, the second heat exchanger 3, and the second heat exchanger 3 are connected in sequence to form a ring to form a refrigeration system. The oil separator 5 is located between the compressor 1 and the first heat exchanger 2, and includes an air inlet, an air outlet, and an oil outlet. The air inlet is connected to the exhaust port of the compressor 1; the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 enters the oil separator 5 from the air inlet. The air outlet is connected to one end of the first heat exchanger 2; the oil separator 5 filters the lubricating oil of the high-temperature and high-pressure gas refrigerant and discharges it from the air outlet and transmits it to the first heat exchanger 2 through the refrigerant pipe; the first heat exchanger 2 acts as a condenser to dissipate the heat of the high-temperature and high-pressure refrigerant gas.

[0085] The compressor 1 is a variable load compressor 1, such as a variable frequency compressor 1, a screw compressor 1, a centrifugal compressor 1, etc.

[0086] The air conditioner further comprises an electronic expansion valve 40 , both ends of which are respectively connected to the oil outlet and the air intake. The opening of the electronic expansion valve 40 is controlled to control the lubricating oil in the oil separator 5 to adapt to the size of the operating load of the compressor 1 .

[0087] The opening control of the electronic expansion valve 40 can be achieved by configuring a controller connected to the electronic expansion valve 40 .

[0088] The air conditioner also includes a second solenoid valve 8, both ends of which are connected to the oil outlet and the air outlet respectively through refrigerant pipes; when the compressor 1 is running at low load, the lubricating oil in the oil separator 5 enters the refrigeration system through the bypass pipeline where the second solenoid valve 8 is located, and returns the oil through the refrigeration cycle.

[0089] Specifically, when the compressor 1 is operating at high or medium load, the second solenoid valve 8 is cut off, and the operation of the compressor 1 at different loads is adapted by controlling the opening of the electronic expansion valve 40; when the compressor 1 is operating at low load, the electronic expansion valve 40 is closed, the second solenoid valve 8 is connected, and the lubricating oil in the oil separator 5 returns to the refrigeration system through the second solenoid valve 8, and circulates back with the refrigeration system; that is, the lubricating oil blocked by the oil separator 5 returns to the refrigeration system from the oil outlet through the second solenoid valve 8 and enters the first heat exchanger 2 with the gas refrigerant coming out of the air outlet, and follows the refrigerant through the first heat exchanger 2, the second heat exchanger 3, and the second heat exchanger 3, and returns to the compressor 1 from the air intake port.

[0090] The air conditioner of the utility model is provided with an electronic expansion valve 40 to connect the oil outlet and the air intake port and to adjust its opening to meet the requirements of the oil return amount when the compressor 1 is running at high and medium loads; when the load is low, the second solenoid valve 8 is controlled to connect so that the lubricating oil in the oil separator 5 returns to the system and follows the system circulation back to the compressor 1, thereby avoiding its influence on the suction superheat and improving the efficiency of the compressor 1 when running at low load.

[0091] In a specific embodiment, referring to Figure 8 On the basis of the previous embodiment, the air conditioner also includes a four-way valve 9, which includes a first port, a second port, a third port, and a fourth port; the first port is connected to the air outlet; the second port is connected to one end of the first heat exchanger 2; the third port is connected to the air intake port; and the fourth port is connected to one end of the second heat exchanger 3.

[0092] During cooling, the first port of the four-way valve 9 is connected to the second port, and the third port is connected to the fourth port; and when the load is low, the lubricating oil returned to the refrigeration system from the oil outlet through the second solenoid valve 8 through the four-way valve 9, the first heat exchanger 2, the second heat exchanger 3, and the second heat exchanger 3 returns to the compressor 1.

[0093] During heating, the first port of the four-way valve 9 is connected to the fourth port, and the second port is connected to the third port; and when the load is low, the lubricating oil returned to the heating system from the oil outlet through the second solenoid valve 8, and then returns to the compressor 1 through the four-way valve 9, the second heat exchanger 3, the second heat exchanger 3, and the first heat exchanger 2.

[0094] In some specific embodiments, reference Figure 1 , Figure 3 , Figure 5 , Figure 7 , Fig. 9 The air conditioner is a water machine, including an outdoor unit, a water module and a terminal module; the outdoor unit includes a compressor 1, a first heat exchanger 2, a second heat exchanger 3, and an oil separator 5; the water module includes a second heat exchanger 3; the outdoor unit and the water module form a refrigeration cycle to generate cold for the medium; the terminal module uses the medium in the water module to transport cold or provide cold water to the space where the terminal is located.

[0095] The air conditioner is of one-on-one type, including an outdoor unit and an indoor unit; the outdoor unit includes a compressor 1, a first heat exchanger 2, a second heat exchanger 3, and an oil separator 5; the indoor unit includes the second heat exchanger 3; the outdoor unit and the indoor unit form a refrigeration cycle, and the second heat exchanger 3 is an evaporator; the indoor unit cools the space in which it is located.

[0096] In some specific embodiments, reference Figure 2 , Figure 4 , Figure 6 , Figure 8 , Fig.10 The air conditioner is a water machine, including an outdoor unit, a water module and a terminal module; the outdoor unit includes a compressor 1, a first heat exchanger 2, a second heat exchanger 3, an oil separator 5, and a four-way valve 9; the water module includes a second heat exchanger 3; the outdoor unit and the water module form a refrigeration cycle or a heating cycle to generate cold or heat for the medium; the terminal module uses the medium in the water module to transport cold or heat to the space where the terminal is located, or provide cold water or hot water.

[0097] The air conditioner is of one-on-one type, including an outdoor unit and an indoor unit; the outdoor unit includes a compressor 1, a first heat exchanger 2, a second heat exchanger 3, an oil separator 5, and a four-way valve 9; the indoor unit includes the second heat exchanger 3; the outdoor unit and the indoor unit form a refrigeration cycle or a heating cycle; the second heat exchanger 3 is an evaporator or a condenser; the indoor unit cools or heats the space in which it is located.

[0098] In some specific embodiments, reference is made to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10 , also includes a gas-liquid separator 10, which includes an inlet and an outlet; the other end or the third port of the second heat exchanger 3 is connected to the inlet; and the outlet is connected to the air intake port.

[0099] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0100] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited to this. Any changes or substitutions that can be easily thought of by technicians familiar with the technical field within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. An air conditioner, comprising a compressor, a first heat exchanger, a second heat exchanger, a throttling device, and an oil separator; the compressor, the first heat exchanger, the throttling device, and the second heat exchanger are connected to form a refrigeration system; the oil separator is located between the compressor and the first heat exchanger, and comprises an air inlet, an air outlet, and an oil outlet; the air inlet is connected to the exhaust port of the compressor; The air outlet is connected to one end of the first heat exchanger; the compressor is a variable load compressor; It is characterized by further comprising: A first oil return pipeline, comprising a first solenoid valve and a first capillary tube connected in series, with two ends respectively connected to the oil outlet and the air intake of the compressor, and used for oil return when the compressor is running at high load when connected; The second solenoid valve has two ends connected to the oil outlet and the air outlet respectively; when connected, it is used to return the lubricating oil in the oil separator to the refrigeration system and circulate the oil when the compressor is running at low load.

2. The air conditioner according to claim 1, characterized in that: Also includes: The second oil return pipeline includes a third solenoid valve and a second capillary connected in series; the oil outlet is connected to the air intake port through the second oil return pipeline; the second capillary has the same inner diameter as the first capillary, and its length is greater than that of the first capillary.

3. The air conditioner according to claim 1, characterized in that: Also includes: The second oil return pipeline includes a third solenoid valve and a second capillary connected in series; the oil outlet is connected to the air intake port through the second oil return pipeline; the second capillary has the same length as the first capillary, and an inner diameter is smaller than the inner diameter of the first capillary.

4. The air conditioner according to claim 1, characterized in that: The compressor is a variable frequency compressor, a screw compressor or a centrifugal compressor.

5. The air conditioner according to any one of claims 1 to 4, characterized in that: It also includes a four-way valve, which includes a first port, a second port, a third port, and a fourth port; the first port is connected to the air outlet; the second port is connected to one end of the first heat exchanger; the third port is connected to the air intake port; and the fourth port is connected to one end of the second heat exchanger.

6. The air conditioner according to claim 5, characterized in that: It also includes a gas-liquid separator, which includes an inlet and an outlet; the third port is connected to the inlet; and the outlet is connected to the air intake port.

7. An air conditioner, comprising a compressor, a first heat exchanger, a second heat exchanger, a throttling device, and an oil separator; the compressor, the first heat exchanger, the throttling device, and the second heat exchanger are connected to form a refrigeration system; the oil separator is located between the compressor and the first heat exchanger, and comprises an air inlet, an air outlet, and an oil outlet; the air inlet is connected to the exhaust port of the compressor; The air outlet is connected to one end of the first heat exchanger; the compressor is a variable load compressor; It is characterized by further comprising: A first solenoid valve, both ends of which are connected to the oil outlet and the air intake of the compressor through a refrigerant pipe, and are used for returning oil when the compressor is running at different loads when connected at different duty ratios; The second solenoid valve is connected to the refrigerant pipeline to form a bypass pipeline; the two ends of the bypass pipeline are respectively connected to the oil outlet and the air outlet; when connected, it is used to allow the lubricating oil in the oil separator to return to the refrigeration system and follow the refrigeration cycle to return oil when the compressor is running at low load.

8. The air conditioner according to claim 7, characterized in that: It also includes a four-way valve, which includes a first port, a second port, a third port, and a fourth port; the first port is connected to the air outlet; the second port is connected to one end of the first heat exchanger; the third port is connected to the air intake port; and the fourth port is connected to one end of the second heat exchanger.

9. The air conditioner according to claim 8, characterized in that: It also includes a gas-liquid separator, which includes an inlet and an outlet; the third port is connected to the inlet; and the outlet is connected to the air intake port.

10. The air conditioner according to any one of claims 7 to 9, characterized in that: The compressor is a variable frequency compressor, a screw compressor or a centrifugal compressor.

Images