Air conditioner

Abstract

The utility model discloses an air conditioner, and belongs to the technical field of air treatment. The air conditioner includes: a compressor for compressing a refrigerant; a D port of the four-way valve is connected with the exhaust end of the compressor; the oil separator is connected between the exhaust end of the compressor and the D port of the four-way valve, and comprises a tank body, the upper part of which is communicated with the exhaust end of the compressor; one end of the outlet pipe is located in the tank body and located on the upper portion of the tank body, the other end of the outlet pipe extends out of the tank body and is connected with a D opening of the four-way valve, the outlet pipe is used for conveying out the separated refrigerant, an oil return hole is formed in the outlet pipe, and oil flows into the outlet pipe when the oil level in the tank body is not lower than the oil return hole; and the oil return pipe is connected between the bottom of the tank body and the air suction side of the compressor and is used for supplying the separated oil to the compressor. The air conditioner can reduce the risk of air-oil operation of the compressor.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and more particularly to an air conditioner. Background Technology

[0002] The compressor is a crucial component of an air conditioner. During operation, the compressor experiences significant internal friction, requiring oil lubrication to ensure its proper functioning.

[0003] In the prior art, the lower end of the gas-liquid separator is provided with an oil return hole, through which the stored oil is discharged into the compressor.

[0004] However, since the gas-liquid separator is located in a low-temperature and low-pressure zone, and its interior contains a mixture of refrigerant and oil, if the return liquid volume is slightly large, the compressor may not be able to draw in enough oil, which could lead to an oil shortage. Utility Model Content

[0005] This application provides an air conditioner that can reduce the risk of compressor operating without oil.

[0006] According to one aspect of this application, an air conditioner includes: a compressor for compressing refrigerant; a four-way valve, the D port of which is connected to the discharge end of the compressor; and an oil separator connected between the discharge end of the compressor and the D port of the four-way valve.

[0007] The oil separator includes: a tank; an inlet pipe, one end of which is connected to the upper part of the tank and the other end of which is connected to the suction side of the compressor, for conveying the mixture of refrigerant and oil from the compressor into the tank; an outlet pipe, one end of which is located inside the tank and at the upper part of the tank, and the other end of which is connected to port D of a four-way valve, for conveying the separated refrigerant out; and an oil return pipe, which is connected between the bottom of the tank and the suction side of the compressor, for supplying the separated oil to the compressor.

[0008] The outlet pipe is equipped with an oil return hole, which is used to supply oil into the outlet pipe when the oil level in the tank is not lower than the oil return hole.

[0009] In this technical solution, the oil separator is designed so that the mixture of oil and refrigerant enters from the top of the tank through the inlet pipe. Under the principles of centrifugal force and mass sedimentation, the oil settles at the bottom of the oil separator, while the refrigerant flows out from the outlet pipe and enters the circulation system. Since the oil separator is constantly under high temperature and high pressure during air conditioner unit operation, the high-temperature oil deposited inside the oil separator can return to the compressor through the return oil pipe. The compressor can continuously draw in high-temperature oil, greatly reducing the risk of the compressor operating with empty oil.

[0010] In addition, by setting an oil return hole on the outlet pipe, the oil return hole can achieve oil equalization when the compressor is biased towards oil.

[0011] In some embodiments, the oil return hole includes: a first oil return hole for supplying oil into the outlet pipe when the oil level in the tank is not lower than the first oil return hole; and a second oil return hole, the height of which is higher than the first oil return hole, for supplying oil into the outlet pipe when the oil level in the tank is not lower than the second oil return hole.

[0012] In the technical solution, the oil level during normal unit operation is between the first and second oil return holes. The first oil return hole is mainly used to ensure that a small amount of oil can enter the outlet pipe and participate in the system circulation. The second oil return hole is mainly used for oil equalization.

[0013] In some embodiments, the air conditioner includes multiple outdoor units connected in parallel in a refrigerant circulation loop; the outdoor unit includes a compressor, a four-way valve and an oil separator; the compressor is provided with an oil leveling port, which is connected to the discharge pipe through an oil leveling pipe; when the oil level in the compressor is not lower than the oil leveling port, the oil can flow through the oil leveling pipe to the oil separator.

[0014] In this technical solution, when oil imbalance occurs, the compressor with more oil discharges the excess oil into the oil separator. The excess oil continues to enter the outlet pipe through the second oil return hole and the first oil return hole to participate in the system circulation. The oil balance between multiple outdoor units is achieved by utilizing the oil distribution following the refrigerant.

[0015] In some embodiments, the area of ​​the second oil return hole is larger than the area of ​​the first oil return hole.

[0016] This technical solution can accelerate the efficiency of oil flowing out of the oil separator through the second return oil hole and participating in the system circulation when oil is biased.

[0017] In some embodiments, the outlet pipe includes: an air inlet section extending along the height direction, with an air inlet formed at the upper end of the air inlet section; an air outlet section extending along the height direction, with the air outlet section connected to the air inlet section via an arc section, and an air outlet formed at the upper end of the air outlet section; and a first oil return hole and a second oil return hole disposed on the air outlet section.

[0018] This technical solution can shorten the flow path of oil in the outlet pipe.

[0019] In some embodiments, the inlet pipe includes: a first pipe section extending in the height direction, the end of the first pipe section located outside the tank body forming an inlet end; and a second pipe section connected to and perpendicular to the first pipe section, the free end of the second pipe section forming an outlet end.

[0020] In some embodiments, the air inlet of the outlet pipe is higher in the height direction than the outlet end of the inlet pipe.

[0021] This technical solution can prevent oil from flowing out of the inlet pipe and then into the outlet pipe.

[0022] In some embodiments, a return oil solenoid valve and a return oil capillary are connected in series on the return oil pipe.

[0023] In this technical solution, the oil return capillary tube controls the amount of oil returned to the compressor from the oil separator. The oil return solenoid valve controls whether oil is returned.

[0024] In some embodiments, the inner diameter d of the oil return capillary satisfies: 0.5mm≤d≤3.0mm, and the length L of the oil return capillary satisfies: 120mm≤L≤500mm.

[0025] In this technical solution, the length of the oil return capillary is increased compared to the existing technology, which can reduce the amount of oil returned, ensuring that the amount of oil returned is greater than the amount of oil supplied to the compressor. At the same time, the increased length of the oil return capillary can reduce the bypass volume of high and low pressure, thereby improving the system energy efficiency.

[0026] In another aspect of this application, an air conditioner includes: a compressor for compressing refrigerant; a four-way valve, the D port of which is connected to the discharge end of the compressor; and an oil separator connected between the discharge end of the compressor and the D port of the four-way valve. The oil separator includes: a tank body, the upper part of which is connected to the discharge side of the compressor; an outlet pipe, one end of which is located inside the tank body and at the upper part of the tank body, and the other end of which extends outside the tank body and is connected to the D port of the four-way valve for conveying the separated refrigerant out; the outlet pipe is provided with an oil return hole for supplying oil into the outlet pipe when the oil level in the tank body is not lower than the oil return hole; and an oil return pipe connected between the bottom of the tank body and the suction side of the compressor for supplying the separated oil to the compressor.

[0027] In this technical solution, the oil separator is designed so that the mixture of oil and refrigerant enters from the top of the tank. Under the principles of centrifugal force and mass sedimentation, the oil settles at the bottom of the oil separator, while the refrigerant flows out from the outlet pipe and enters the circulation system. Since the oil separator is constantly under high temperature and pressure during air conditioner unit operation, the high-temperature oil deposited inside the oil separator can return to the compressor through the oil return pipe. The compressor can continuously draw in high-temperature oil, greatly reducing the risk of the compressor operating with empty oil. Furthermore, by setting an oil return hole on the outlet pipe, the oil return hole can achieve oil equalization when the compressor is biased towards oil. Attached Figure Description

[0028] Figure 1 A schematic diagram of an air conditioner according to some embodiments is shown;

[0029] Figure 2 A schematic diagram of the refrigerant circuit of an air conditioner according to some embodiments is shown;

[0030] Figure 3 A perspective view of an oil separator for an air conditioner according to some embodiments is shown;

[0031] Figure 4 A cross-sectional view of an oil separator of an air conditioner according to some embodiments is shown;

[0032] Figure 5 A schematic diagram of an air conditioner according to some other embodiments is shown;

[0033] Figure 6 A schematic diagram of the refrigerant circuit of an outdoor unit according to some other embodiments is shown;

[0034] Figure 7 A calculation model of the return oil hole according to some embodiments is shown.

[0035] In the above diagrams, 100 is the outdoor unit; 111 is the compressor; 111a is the oil leveling port; 112 is the outdoor heat exchanger; 113 is the four-way valve; 114 is the outdoor throttling device; 115 is the gas-liquid separator; 116 is the outdoor fan; 117 is the liquid-side shut-off valve; 118 is the gas-side shut-off valve; 1191 is the oil return capillary tube; 1192 is the oil return solenoid valve; 200 is the indoor unit; 211 is the indoor heat exchanger; 212 is the indoor throttling device; 2 13. Indoor fan; 300. Oil separator; 310. Tank; 311. Cylinder; 312. Upper end cover; 313. Lower end cover; 320. Inlet pipe; 320a. Inlet; 320b. Outlet; 321. First pipe section; 322. Second pipe section; 330. Outlet pipe; 330a. Air inlet; 330b. Air outlet; 331. First oil return hole; 332. Second oil return hole; 333. Air inlet pipe section; 334. Air outlet pipe section. Detailed Implementation

[0036] To make the objectives and implementation methods of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the exemplary embodiments described are only some embodiments of this application, and not all embodiments.

[0037] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0038] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0039] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0040] The embodiments of this application will now be described in detail, with examples of embodiments shown in the accompanying drawings.

[0041] Reference Figure 1 An air conditioner according to an embodiment of this application includes an outdoor unit 100, located in an outdoor space and used to perform heat exchange between a refrigerant and outdoor air; and an indoor unit 200, located in an indoor space and used to perform heat exchange between a refrigerant and indoor air.

[0042] Reference Figure 2 The outdoor unit 100 includes: a compressor 111 for compressing refrigerant; an oil separator 300 for separating oil from refrigerant; an outdoor heat exchanger 112 for performing heat exchange between outdoor air and refrigerant; a four-way valve 113 for selectively guiding the refrigerant compressed by the compressor 111 to the outdoor heat exchanger 112 or the indoor unit 200 according to the heating or cooling mode; an outdoor throttling device 114 for reducing the pressure of the refrigerant; and a gas-liquid separator 115 for preventing unevaporated liquid refrigerant from flowing to the compressor 111.

[0043] The discharge end of compressor 111 is connected to the inlet of oil separator 300, the outlet of oil separator 300 is connected to port D of four-way valve 113, port C of four-way valve 113 is connected to outdoor heat exchanger 112, port E of four-way valve 113 is connected to gas-side shut-off valve 118, port S of four-way valve is connected to the inlet of gas-liquid separator 115, and the outlet of gas-liquid separator 115 is connected to the suction end of compressor 111.

[0044] When compressor 111 is powered on, it uses the rotational force of the compressor motor to compress the low-pressure gaseous refrigerant to a high pressure.

[0045] The oil separator 300 separates oil from the high-pressure steam discharged from the compressor. Based on the principle of reducing airflow velocity and changing airflow direction, oil particles in the high-pressure steam are separated under the influence of gravity.

[0046] In cooling mode, the four-way valve 113 guides the refrigerant compressed in the compressor 111 to the outdoor heat exchanger 112, and in heating mode, it guides the refrigerant compressed in the compressor 111 to the indoor unit 200.

[0047] The outdoor heat exchanger 112 functions as a condenser in cooling mode to condense the refrigerant compressed by the compressor 111, thereby liquefying the gaseous refrigerant. In heating mode, it functions as an evaporator to evaporate the refrigerant depressurized by the indoor unit 200, thereby vaporizing the liquid refrigerant.

[0048] Outdoor fan 116 blows outdoor air to outdoor heat exchanger 112.

[0049] The outdoor throttling device 114 reduces the pressure of the refrigerant by throttling it. When the refrigerant passes through a narrow passage, its pressure decreases without heat exchange with the outside. Specifically, the outdoor throttling device 114 can be an expansion valve or a capillary tube, etc.

[0050] The indoor unit 200 includes an indoor heat exchanger 211, which performs heat exchange between the refrigerant and the indoor air.

[0051] In cooling mode, the indoor heat exchanger 211 is used as an evaporator to evaporate low-pressure liquid refrigerant, thereby vaporizing the liquid refrigerant. In heating mode, it is used as a condenser to condense high-pressure gaseous refrigerant, thereby liquefying the gaseous refrigerant.

[0052] The indoor fan 213 blows the air that has exchanged heat with the refrigerant through the indoor heat exchanger 211 into the indoor space.

[0053] The indoor unit 200 may include an indoor throttling device 212. The indoor throttling device 212 reduces the pressure of the refrigerant by throttling it. When the refrigerant passes through a narrow passage, its pressure decreases without heat exchange with the outside. Specifically, the indoor throttling device 212 may be an expansion valve or a capillary tube, etc.

[0054] The indoor throttling device 212 is used to reduce the pressure of the refrigerant guided to the indoor heat exchanger 211 during cooling. The outdoor throttling device 114 may not have a throttling function during cooling and may be in a fully open state.

[0055] The indoor throttling device 212 does not throttle during heating. The outdoor throttling device 114 reduces the pressure of the refrigerant guided to the outdoor heat exchanger 112 during heating.

[0056] There may be multiple indoor units 200. The indoor heat exchangers 211 of the multiple indoor units 200 are connected in parallel in the refrigerant circulation system. An indoor throttling device 212 is connected in series on the branch where each indoor heat exchanger 211 is located. The indoor throttling device 212 is located between the indoor heat exchanger 211 and the liquid-side shut-off valve 117.

[0057] The flow of refrigerant in the air conditioner in cooling or heating mode will be described below.

[0058] When the air conditioner is operating in cooling mode, the compressor 111 of the outdoor unit 100 compresses the refrigerant to a high pressure. As the refrigerant is compressed, its pressure and temperature increase.

[0059] The oil separator 300 separates the oil from the high-pressure gaseous refrigerant and supplies the oil back to the compressor 111.

[0060] The refrigerant separated by the oil separator 300 is guided to the outdoor heat exchanger 112 via the four-way valve 113. In the outdoor heat exchanger 112, the refrigerant condenses, and heat exchange occurs between the refrigerant and the outdoor air during this process. Specifically, the refrigerant changes from a gaseous state to a liquid state.

[0061] The refrigerant is supplied to the indoor unit 200 via the outdoor throttling device 114 through the liquid-side shut-off valve 117.

[0062] The refrigerant supplied to the indoor unit 200 is depressurized by the indoor throttling device 212, and the temperature of the refrigerant is reduced at the same time.

[0063] The depressurized refrigerant is evaporated through the indoor heat exchanger 211, and heat exchange between the refrigerant and the indoor air is performed simultaneously during the evaporation of the refrigerant. Specifically, the refrigerant changes to a gaseous state.

[0064] Refrigerant is supplied to the outdoor unit 100 via the gas-side shut-off valve 118 and to the gas-liquid separator 115 via the four-way valve 113. In the gas-liquid separator 115, the refrigerant is separated into unevaporated liquid refrigerant and evaporated gaseous refrigerant, and the gaseous refrigerant is supplied to the compressor 111 again to complete one refrigerant cycle.

[0065] As described above, in cooling mode, the air conditioner can cool the indoor air by utilizing the heat exchange between the refrigerant generated in the indoor heat exchanger 211 and the indoor air.

[0066] When the air conditioner is in heating mode, the refrigerant is compressed to high pressure by the compressor 111 of the outdoor unit 100, and the temperature of the refrigerant increases with the pressure of the refrigerant.

[0067] The oil separator 300 separates the oil from the high-pressure gaseous refrigerant and supplies the oil back to the compressor 111.

[0068] The refrigerant separated by the oil separator 300 passes through the four-way valve 113 and is then guided to the indoor unit 200 along the gas-side shut-off valve 118.

[0069] The refrigerant is condensed by the indoor heat exchanger 211, and heat exchange occurs between the refrigerant and the indoor air during the condensation process. Specifically, the refrigerant changes from a gaseous state to a liquid state.

[0070] The condensed refrigerant is supplied to the outdoor unit 100 via the indoor throttling device 212 and the liquid-side shut-off valve 117.

[0071] The refrigerant supplied to the outdoor unit 100 is depressurized by the outdoor throttling device 114, and the temperature of the refrigerant is reduced at the same time.

[0072] The depressurized refrigerant is evaporated through the outdoor heat exchanger 112, and heat exchange occurs between the refrigerant and the outdoor air during the evaporation process. Specifically, the refrigerant changes to a gaseous state.

[0073] The refrigerant from the outdoor heat exchanger 112 is supplied to the gas-liquid separator 115 via the four-way valve 113. In the gas-liquid separator 115, the refrigerant is separated into unevaporated liquid refrigerant and evaporated gaseous refrigerant, and the gaseous refrigerant is supplied to the compressor 111 again to complete one refrigerant cycle.

[0074] As described above, in heating mode, the air conditioner can use the heat exchange between the refrigerant generated in the indoor heat exchanger 211 and the indoor air to heat the indoor air.

[0075] The above embodiments are described using multiple indoor units 200 as an example. However, this application is also applicable to models with a single indoor unit 200.

[0076] In some embodiments, the structure of the oil separator 300 is the same as that of the gas-liquid separator 115.

[0077] In some embodiments, refer to Figure 3 and Figure 4 The oil separator 300 includes a tank 310. The tank 310 is used as a container. The tank 310 is a closed cylinder, which constitutes the general appearance of the oil separator 300.

[0078] In some embodiments, the tank 310 may include a cylindrical body 311. The cylindrical body 311 is cylindrical with open upper and lower ends.

[0079] The tank body 310 may include an upper cover 312. The upper cover 312 is connected to the upper end of the cylinder 311 and is used to close the upper end of the cylinder 311.

[0080] The tank body 310 may include a lower end cover 313. The lower end cover 313 is connected to the bottom end of the cylinder body 311 and is used to close the bottom end of the cylinder body 311.

[0081] In some embodiments, the upper part of the oil separator 300 is connected to the exhaust side of the compressor 111, so that the mixture of refrigerant and oil discharged by the compressor 111 enters the tank 310 from the upper part of the oil separator 300.

[0082] In some embodiments, the oil separator 300 may include an inlet pipe 320 for delivering a mixture of refrigerant and oil into the tank 310. The inlet pipe 320 extends through the tank 310.

[0083] A portion of the inlet pipe 320 is located outside the tank body 310, and a portion of the inlet pipe 320 extends into the tank body 310.

[0084] The external port of the inlet pipe 320 is the inlet 320a of the oil separator 300, which is used to supply refrigerant and oil.

[0085] The port of the inlet pipe 320 that extends into the tank 310 is the outlet 320b of the inlet pipe 320, which is used to allow refrigerant and oil to flow out into the tank 310.

[0086] The oil separator 300 may include an outlet pipe 330 for allowing refrigerant to flow out of the tank 310. The outlet pipe 330 extends through the tank 310.

[0087] Most of the outlet pipe 330 is located inside the tank 310, and one end of the outlet pipe 330 extends outside the tank 310.

[0088] The port of the outlet pipe 330 located inside the tank 310 is the inlet 330a, which is used to allow gaseous refrigerant to flow into the outlet pipe 330; the port of the outlet pipe 330 exposed outside the tank 310 is the outlet 330b of the oil separator 300, which is used to allow gaseous refrigerant to flow out of the oil separator 300.

[0089] Combination Figure 2 In the refrigerant flow path, the discharge end of the compressor 111 is connected to the inlet 320a of the oil separator 300 through the discharge pipe P1, and the outlet 330b of the oil separator 300 is connected to the D port of the four-way valve 113, so that the refrigerant compressed by the compressor 111 flows to the inlet pipe 320. After the oil separator 300 separates the refrigerant from the oil, the refrigerant continues to flow through the outlet pipe 330 to the four-way valve 113 and enters the system circulation.

[0090] In some embodiments, the bottom of the tank 310 is connected to the suction side of the compressor 111 via the oil return pipe P3.

[0091] A return oil port can be installed at the bottom of the tank body 310, and the return oil port is connected to the return oil pipe P3.

[0092] The outlet of the gas-liquid separator 115 is connected to the suction end of the compressor 111 via the return gas pipe P2. The oil return pipe P3 can be connected to the return gas pipe P2 to achieve the connection between the oil return pipe P3 and the suction end of the compressor 111.

[0093] The working principle of the oil separator 300 in this application is as follows: the mixture of refrigerant and oil discharged from the compressor 111 enters the interior of the oil separator 300 through the inlet pipe 320. Utilizing centrifugal force and the principle of mass sedimentation, the oil is separated and deposited at the bottom of the oil separator 300. The refrigerant flows out from the outlet pipe 330 of the oil separator 300 into the circulation system. The oil accumulated at the bottom of the oil separator 300 returns to the suction end of the compressor 111 through the oil return pipe P3, forming a cycle.

[0094] In the prior art, the oil discharged from the compressor 111 is usually returned to the compressor 111 through the gas-liquid separator 115. Since the gas-liquid separator 115 is in a low temperature and low pressure zone and contains a mixture of refrigerant and oil, if the amount of returned liquid is slightly large, it will result in a low oil content inside the gas-liquid separator 115, and the compressor will not be able to draw in enough oil, which may lead to the risk of oil shortage.

[0095] In the embodiments of this application, the oil separator 300 is always in a high temperature and high pressure state during the operation of the air conditioning unit. The oil returns from the bottom of the oil separator 300 to the suction end of the compressor 111 through the oil return pipe P3. The compressor 111 can continuously draw in high temperature oil, which greatly reduces the risk of the compressor 111 operating with empty oil.

[0096] In some embodiments, the outlet pipe 330 is provided with an oil return hole. When the oil level of the oil accumulated in the oil separator 30 is not lower than the height of the oil return hole, the oil will enter the outlet pipe 330 through the oil return hole and flow out of the oil separator 300 along the outlet pipe 330 to enter the system circulation.

[0097] In single-compressor models, oil enters the outlet pipe 330 through the oil return hole, ensuring that a small portion of the oil participates in the system circulation. In multi-compressor models, when the compressor experiences oil imbalance, oil enters the outlet pipe 330 through the oil return hole, allowing the oil to participate in the system circulation and achieve oil equalization.

[0098] A single-compressor model refers to an air conditioner with only one compressor in its refrigerant circulation loop. A multi-compressor model refers to an air conditioner with multiple compressors in its refrigerant circulation loop. "Oil imbalance" means that one compressor has an excess of oil, while another compressor is short of oil.

[0099] In some embodiments, continue to refer to Figure 2 An oil return capillary tube 1191 is connected to the oil return pipe P3. The diameter of the oil return capillary tube 1191 is smaller than that of the oil return pipe P3. The oil return capillary tube 1191 uses capillary action and pressure difference to control the oil flow and prevent excessive oil from flowing to the compressor 111.

[0100] In some embodiments, the inner diameter d of the oil return capillary 1191 satisfies: 0.5mm≤d≤3.0mm, and the length L of the oil return capillary 1191 satisfies: 120mm≤L≤500mm.

[0101] Compared with the prior art, the length of the oil return capillary 1191 in this application can be increased to reduce the amount of oil returned, ensuring that the amount of oil returned is greater than the amount of oil supplied by the compressor 111 (i.e. the amount of oil discharged through the exhaust end of the compressor 111). At the same time, the increased length of the oil return capillary 1191 can reduce the bypass volume of high and low pressure and improve the system energy efficiency.

[0102] In some embodiments, a return oil solenoid valve 1192 is connected to the return oil pipe P3 to control the opening or closing of the return oil pipe P3. When the return oil solenoid valve 1192 is open, the return oil pipe P3 is connected; when the return oil solenoid valve 1192 is closed, the return oil pipe P3 is disconnected.

[0103] In some embodiments, continue to refer to Figure 4 The inlet pipe 320 is "L" shaped and includes a first pipe section 321 that extends along the height direction of the oil separator 300. The end of the first pipe section 321 located outside the tank 310 forms the inlet 320a of the inlet pipe 320.

[0104] The inlet pipe 320 includes a second pipe section 322, which is connected to and perpendicular to the first pipe section 321. The free end of the second pipe section 322 forms the outlet 320b of the inlet pipe 320.

[0105] The second pipe section 322 and the first pipe section 321 can be connected by an arc segment.

[0106] In some embodiments, the outlet pipe 330 is U-shaped. The air inlet 330a of the outlet pipe 330 is located inside the tank 310, and the air outlet 330b of the outlet pipe 330 is located outside the tank 310.

[0107] The outlet pipe 330 includes an intake pipe section 333. The intake pipe section 333 extends vertically along the height direction, and the upper end of the intake pipe section 333 forms an intake port 330a.

[0108] The outlet pipe 330 includes an outlet pipe section 334. The outlet pipe section 334 extends vertically along the height direction, and its bottom end is connected to the bottom end of the inlet pipe section 333 via an arc-shaped pipe section. The upper end of the outlet pipe section 334 forms an outlet 330b.

[0109] In some embodiments, the oil return hole is located on the air outlet section 334, which reduces the flow path of oil in the air outlet section 330 compared to the oil return hole being located on the air inlet section 333 of the outlet pipe 330.

[0110] In some embodiments, the air inlet 330a of the outlet pipe 330 may be higher in the height direction than the outlet 320b of the inlet pipe 320.

[0111] The mixture of oil and gaseous refrigerant flowing out of inlet pipe 320 flows downwards due to the heavier oil and upwards due to the lighter gaseous refrigerant. Because the inlet 330a of outlet pipe 330 is higher, it prevents oil from flowing into outlet pipe 330 from entering through inlet 330a when it flows downwards.

[0112] According to an embodiment of this application, the portion of the inlet pipe 320 that passes through the tank body 310 is welded to the tank body 310 to achieve a fixed connection between the inlet pipe 320 and the tank body 310.

[0113] The portion of the outlet pipe 330 that passes through the tank body 310 is welded to the tank body 310 to achieve a fixed connection between the outlet pipe 330 and the tank body 310.

[0114] In some embodiments, the oil return hole includes a first oil return hole 331. When the oil level in the oil separator 300 is not lower than the height of the first oil return hole 331, the oil will enter the outlet pipe 330 through the first oil return hole 331 and flow out along the outlet pipe 330 to enter the system circulation.

[0115] The oil return hole includes a second oil return hole 332. The height of the second oil return hole 332 is higher than that of the first oil return hole 331.

[0116] When the oil level in the oil separator 300 is between the first return oil hole 331 and the second return oil hole 332, oil enters the outlet pipe 330 from the first return oil hole 331 and enters the system circulation. When the oil level in the oil separator 300 is not lower than the second return oil hole 332, oil enters the outlet pipe 330 from the first return oil hole 331 and the second return oil hole 332 and enters the system circulation.

[0117] The second oil return hole 332 mainly plays the role of oil equalization in multi-compressor systems.

[0118] In some embodiments, refer to Figure 5 and Figure 6 The outdoor unit 100 may include multiple units connected in parallel with the indoor unit 200.

[0119] The gas-side shut-off valve 118 of each outdoor unit 100 is connected to one end of the indoor heat exchanger 211, and the liquid-side shut-off valve 117 of each outdoor unit 100 is connected to the other end of the indoor heat exchanger 211.

[0120] There is a tendency for uneven oil levels to occur between the compressors 111 of the outdoor unit 100, meaning that one compressor 111 contains more oil than the other.

[0121] Therefore, for multi-module models (models with multiple outdoor units), it is necessary to address the oil imbalance issue in compressor 111.

[0122] In some embodiments, the compressor 111 is provided with an oil equalization port 111a, which is connected to the exhaust pipe P1 through an oil equalization pipe P4.

[0123] When the oil level in compressor 111 is not lower than the oil leveling port 111a, the oil flows through the oil leveling pipe P4 to the oil separator 300, which can prevent too much oil in compressor 111.

[0124] During normal operation of the unit, the oil level is between the first oil return hole 331 and the second oil return hole 332. When an oil imbalance occurs, the oil level inside the compressor with more oil rises to the oil equalization port 111a. The oil inside the compressor 111 is carried out of the compressor 111 by the oil equalization pipe P4 and enters the oil separator 300. At this time, the oil return volume of the oil return capillary 1191 is less than the oil return volume of the oil equalization pipe P4. The oil level inside the oil separator 300 continues to rise to the second oil return hole 332. At this time, the excess oil inside the unit is carried out of the outdoor unit through the double oil return holes of the first oil return hole 331 and the second oil return hole 332 and discharged into the indoor unit. The oil balance of multiple outdoor units is achieved through the refrigerant distribution of the system, thus realizing oil equalization.

[0125] In some embodiments, unlike the embodiments described above, there is one outdoor unit 100 and multiple compressors 111 inside the outdoor unit 110. The multiple compressors 111 are arranged in parallel in the refrigerant circulation loop.

[0126] When compressor 111 experiences oil imbalance, the oil return hole of oil separator 330 can be used to achieve oil equalization. The oil equalization principle is the same as the above-mentioned embodiments of multiple outdoor units, and will not be repeated here.

[0127] In some embodiments, the area of ​​the second oil return hole 332 may be larger than the area of ​​the first oil return hole 331. This can accelerate the efficiency of oil flowing from the second oil return hole 332 through the outlet pipe 330 out of the oil separator 300 and participating in the system circulation when there is a bias.

[0128] The diameter of the first return oil hole is between 0.5 and 5.0 mm, and the specific value can be calculated based on the actual working conditions.

[0129] The diameter of the second return oil hole is between 0.5 and 5.0 mm, and the specific value can be calculated based on the actual working conditions.

[0130] The design principle of this application is as follows: oil supply from the first oil return hole and the second oil return hole > oil supply from the equalization pipe > oil return from the return capillary > normal oil supply from the compressor > oil supply from the first oil return hole.

[0131] Normally, the amount of oil supplied to a compressor can be measured and is known. Based on the normal amount of oil supplied to the compressor, the diameter and length of the return capillary tube can be calculated so that the amount of oil returned by the return capillary tube is greater than the normal amount of oil supplied to the compressor, ensuring that there is always oil in the compressor.

[0132] The oil return rate of the first return port is mainly used to ensure that a small portion of the oil participates in the system circulation. During the design phase, a suitable return rate for the first return port can be selected based on system requirements, and then the area of ​​the first return port can be calculated based on this return rate. The height of the first return port in the oil separator is mainly determined by the designed oil storage capacity of the oil separator.

[0133] The height of the first return oil hole is calculated by dividing the designed oil storage capacity by the cross-sectional area of ​​the oil separator.

[0134] The height difference between the second oil return hole and the first oil return hole can be determined based on the uneven oil storage volume when the maximum oil deviation occurs between modules.

[0135] The height difference between the second and first oil return holes is calculated by dividing the uneven oil volume at maximum oil deviation by the cross-sectional area of ​​the oil separator.

[0136] The oil flow rate from the first and second return oil holes is greater than that from the oil equalization pipe. This is to ensure that the oil supplied from the oil equalization pipe to the oil separator can flow out of the oil separator through the dual return oil holes as quickly as possible, participating in the system circulation and improving oil equalization efficiency. Based on this oil flow rate relationship, a suitable oil flow rate for the dual return oil holes can be selected. Combining this with the known oil flow rate from the first return oil hole, the oil flow rate from the second return oil hole can be calculated. Furthermore, based on the oil flow rate from the second return oil hole, the area of ​​the second return oil hole can be calculated.

[0137] The following is combined Figure 7 This section introduces the method for calculating the area of ​​the oil return hole:

[0138] Symbol explanation:

[0139] P1: External pressure at the oil return hole

[0140] P2: Pressure inside the pipe at the oil return port

[0141] P0: Inlet pressure (internal pressure)

[0142] h l The height from the oil return hole to the oil level

[0143] ug / G g Inlet gaseous refrigerant flow rate and mass flow rate

[0144] u l / G l Oil return hole (oil) flow rate and mass flow rate

[0145] External pressure P1 at the return oil port:

[0146] P1=P0+ρ l gh l

[0147] The internal pressure P2 after the return oil hole passes through:

[0148] P2 = P0 - AP

[0149] In the formula:

[0150] λ: Coefficient of friction inside the pipe

[0151] ξ1: Losses caused by flow contraction at the inlet of the outlet pipe

[0152] ξ2: Losses caused by bending of the outlet pipe (not applicable to the bottom outlet pipe)

[0153] Pressure difference between inside and outside the pipe at the return oil port:

[0154] P1-P2=AP+ρ l gh l

[0155] The compressor oil flows into the outlet pipe from the return oil port, considering a small-hole throttling device. The mass flow rate is:

[0156]

[0157] In the formula:

[0158] α: Orifice flow coefficient

[0159] A: Area of ​​oil return hole

[0160] Substituting the previous formula and simplifying it, we get:

[0161]

[0162] Since the oil return volume is known, the area of ​​the oil return hole can be deduced as follows:

[0163]

[0164] As can be seen from the above, according to the embodiment of this application, the bottom of the oil separator 300 is connected to the suction end of the compressor 111 through the oil return pipe P3. Since the oil separator 300 is always in a high temperature and high pressure state during the operation of the air conditioner unit, the oil returns from the bottom of the oil separator 300 to the suction end of the compressor 111 through the oil return pipe P3. The compressor 111 can continuously suck in high temperature oil, which greatly reduces the risk of the compressor 111 operating with empty oil.

[0165] In addition, an oil return hole is provided on the outlet pipe 330 of the oil separator 300 to achieve oil equalization.

[0166] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0167] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the described embodiments and various different variations of embodiments suitable for specific use considerations.

Claims

1. An air conditioner, characterized in that, include: A compressor is used to compress refrigerant; A four-way valve, wherein port D of the four-way valve is connected to the discharge end of the compressor; An oil separator, connected between the discharge end of the compressor and port D of the four-way valve, is used to separate refrigerant and oil. The oil separator includes: Tank body; An inlet pipe, one end of which is connected to the upper part of the tank, and the other end of which is connected to the exhaust end of the compressor via an exhaust pipe, is used to deliver refrigerant and oil from the compressor into the tank. An outlet pipe, one end of which is located inside the tank and at the top of the tank, and the other end of which is connected to port D of the four-way valve, for conveying the separated refrigerant to the four-way valve. The outlet pipe is equipped with: The oil return hole is used to supply oil into the outlet pipe when the oil level in the tank is not lower than the oil return hole. The oil return pipe is connected between the bottom of the tank and the suction side of the compressor, and is used to supply the separated oil to the compressor.

2. The air conditioner according to claim 1, characterized in that, The oil return hole includes: The first return oil hole is used to supply oil into the outlet pipe when the oil level in the tank is not lower than the first return oil hole; The second oil return hole, which is higher than the first oil return hole, is used to supply oil into the outlet pipe when the oil level in the tank is not lower than the second oil return hole.

3. The air conditioner according to claim 2, characterized in that, The air conditioner includes multiple outdoor units connected in parallel in a refrigerant circulation loop; each outdoor unit includes the compressor, the four-way valve, and the oil separator. The compressor is provided with an oil equalization port, which is connected to the exhaust pipe via an oil equalization pipe. When the oil level in the compressor is not lower than the oil leveling port, the oil can flow through the oil leveling pipe to the oil separator.

4. The air conditioner according to claim 2, characterized in that, The area of ​​the second oil return hole is larger than the area of ​​the first oil return hole.

5. The air conditioner according to claim 2, characterized in that, The outlet pipe includes: An intake pipe section extends along the height direction, and the upper end of the intake pipe section forms the air inlet of the outlet pipe; An exhaust pipe section extends along the height direction, and the lower end of the exhaust pipe section is connected to the lower end of the intake pipe section through an arc pipe section. The upper end of the exhaust pipe section forms the exhaust port of the outlet pipe. The first oil return hole and the second oil return hole are located on the air outlet pipe section.

6. The air conditioner according to claim 1, characterized in that, The inlet pipe includes: A first pipe section extends along the height direction, and at least a portion of the first pipe section is located outside the tank body; The second pipe section is connected to and perpendicular to the first pipe section, and the second pipe section is located inside the tank.

7. The air conditioner according to claim 1, characterized in that, The air inlet of the outlet pipe is higher in the vertical direction than the outlet of the inlet pipe.

8. The air conditioner according to claim 1, characterized in that, The return oil pipe is connected in series with a return oil solenoid valve and a return oil capillary.

9. The air conditioner according to claim 8, characterized in that, The inner diameter d of the oil return capillary satisfies: 0.5mm≤d≤3.0mm, and the length L of the oil return capillary satisfies: 120mm≤L≤500mm.

10. An air conditioner, characterized in that, include: A compressor is used to compress refrigerant; A four-way valve, wherein port D of the four-way valve is connected to the discharge end of the compressor; An oil separator, connected between the discharge end of the compressor and port D of the four-way valve, is used to separate refrigerant and oil. The oil separator includes: The tank body, the upper part of which is connected to the exhaust end of the compressor; An outlet pipe, one end of which is located inside the tank and at the top of the tank, and the other end of which is connected to port D of the four-way valve, for conveying the separated refrigerant to the four-way valve. The outlet pipe is equipped with: The oil return hole is used to supply oil into the outlet pipe when the oil level in the tank is not lower than the oil return hole. The oil return pipe is connected between the bottom of the tank and the suction side of the compressor, and is used to supply the separated oil to the compressor.

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