Air conditioner refrigerant oil content detection device and method and air conditioner system

Abstract

The invention relates to the technical field of air conditioners, and provides an air conditioner refrigerant oil content detection device and method and an air conditioner system.The air conditioner refrigerant oil content detection device comprises a collecting tank, a pressure sensor and a controller, and a first valve and a second valve are arranged at the two ends of the collecting tank and used for collecting a refrigerant and refrigerant oil mixture of a compressor or an oil separator; the pressure sensor is connected with the collecting tank and is used for detecting initial pressure and stable pressure in the collecting tank at previous and later moments; the controller is connected with the first valve, the second valve and the pressure sensor and used for controlling opening and closing of the first valve and the second valve and obtaining the oil content of the refrigerant according to the detected pressure difference between the initial pressure and the stable pressure. The oil content of the refrigerant can be accurately detected, so that reliable operation of the compressor is guaranteed, and the device has the advantages of being simple in structure, low in cost, stable, reliable and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and particularly to an air conditioner refrigerant oil content detection device, method and air conditioner system. Background Art

[0002] In the related art, after the refrigerant and the refrigerating oil of the air conditioner compressor are discharged together for circulation and then return to the compressor. The refrigerant oil content of the compressor plays an important role in the normal operation of the compressor. When the refrigerant oil content of the compressor is low, it is easy to cause abnormal operation of the compressor, and in severe cases, even damage to the compressor.

[0003] Therefore, there is an urgent need for an air conditioner refrigerant oil content detection device. Summary of the Invention

[0004] The present invention provides an air conditioner refrigerant oil content detection device, method and air conditioner system, which can achieve accurate detection of the refrigerant oil content, thereby ensuring the reliable operation of the compressor, and has the characteristics of simple structure, low cost, stability and reliability.

[0005] The present invention provides an air conditioner refrigerant oil content detection device, including:

[0006] A collection tank, with a first valve and a second valve provided at both ends of the collection tank, for collecting the refrigerant and refrigerating oil mixture of the compressor or the oil separator;

[0007] A pressure sensor, connected to the collection tank, for detecting the initial pressure and the stable pressure at different times inside the collection tank;

[0008] A controller, respectively connected to the first valve, the second valve and the pressure sensor, for controlling the opening and closing of the first valve and the second valve, and obtaining the refrigerant oil content according to the pressure difference between the detected initial pressure and the stable pressure.

[0009] For the air conditioner refrigerant oil content detection device provided by the present invention, by providing a first valve and a second valve at both ends of the collection tank, the refrigerant and refrigerating oil mixture of the compressor or the oil separator can be collected; by connecting the pressure sensor to the collection tank, the initial pressure and the stable pressure at different times inside the collection tank can be detected; by connecting the controller to the first valve, the second valve and the pressure sensor respectively, the opening and closing of the first valve and the second valve can be controlled, so that the refrigerant and refrigerating oil mixture is collected inside the collection tank, and the refrigerant oil content is obtained according to the pressure difference between the detected initial pressure and the stable pressure. Therefore, the present invention can achieve accurate detection of the refrigerant oil content, thereby ensuring the reliable operation of the compressor, and has the characteristics of simple structure, low cost, stability and reliability.

[0010] According to the air conditioner refrigerant oil content detection device provided by the present invention, it further includes:

[0011] An alarm, connected to the controller, the controller is further configured to determine whether the compressor is oil-deficient according to the oil content rate of the refrigerant. When the compressor is oil-deficient and still oil-deficient after an oil return operation, the controller controls the alarm to give an alarm.

[0012] The air-conditioning refrigerant oil content rate detection device provided by the present invention can also determine whether the refrigerant oil in the compressor is sufficient according to the detected refrigerant oil content rate, and can give an alarm when it is insufficient, so as to remind the user to perform maintenance, thereby further ensuring the reliable operation of the compressor.

[0013] According to an air-conditioning refrigerant oil content rate detection device provided by the present invention, the collection tank is connected in parallel to an oil return branch between the oil outlet of the oil separator and the suction port of the compressor.

[0014] According to an air-conditioning refrigerant oil content rate detection device provided by the present invention, the collection tank is a heat exchange type collection tank, and the collection tank is connected in parallel between the fourth valve port of the four-way valve and the suction port of the compressor through a cooling circuit.

[0015] The air-conditioning refrigerant oil content rate detection device provided by the present invention can also make full use of the low-temperature refrigerant in the air-conditioning system to cool the collection tank, accelerate the condensation process of the refrigerant in the collection tank, thereby improving the detection efficiency and realizing the full utilization of energy.

[0016] According to an air-conditioning refrigerant oil content rate detection device provided by the present invention, the collection tank is connected to the compressor through a bypass branch.

[0017] The present invention also provides a detection method for the above-mentioned air-conditioning refrigerant oil content rate detection device, including:

[0018] During the operation of the compressor, control the first valve to open and the second valve to close. After waiting for a preset time, control the first valve to close, so that the collection tank collects the refrigerant and refrigerant oil mixture of the compressor or the oil separator;

[0019] Detect the initial pressure and stable pressure in the collection tank at different times through the pressure sensor;

[0020] Obtain the refrigerant oil content rate according to the pressure difference between the detected initial pressure and the stable pressure.

[0021] The detection method of the air-conditioning refrigerant oil content rate detection device provided by the present invention can achieve accurate detection of the refrigerant oil content rate, thereby ensuring the reliable operation of the compressor.

[0022] According to a detection method for an air-conditioning refrigerant oil content rate detection device provided by the present invention, the step of obtaining the refrigerant oil content rate according to the pressure difference between the detected initial pressure and the stable pressure includes:

[0023] Determine the refrigerant mass and the refrigerant oil mass according to the pressure difference;

[0024] Obtain the oil content rate of the refrigerant according to the refrigerant mass and the refrigerant oil mass.

[0025] According to the detection method of an air-conditioning refrigerant oil content rate detection device provided by the present invention, the step of obtaining the oil content rate of the refrigerant according to the refrigerant mass and the refrigerant oil mass includes:

[0026] M1 = ρ r *V*(P1 - P2);

[0027] M2 = ρ o *V*P2;

[0028] η = M2 / (M1 + M2);

[0029] Wherein, M1 is the refrigerant mass, ρ r is the refrigerant density, V is the volume of the collection tank, P1 is the initial pressure, and P2 is the stable pressure; M2 is the refrigerant oil mass, ρ o is the refrigerant oil density; η is the oil content rate of the refrigerant.

[0030] According to the detection method of an air-conditioning refrigerant oil content rate detection device provided by the present invention, it further includes:

[0031] Determine whether the compressor is short of oil according to the oil content rate of the refrigerant. When the compressor is short of oil and still short of oil after an oil return operation, control the alarm to alarm.

[0032] The detection method of the air-conditioning refrigerant oil content rate detection device provided by the present invention can also judge whether the refrigerant oil in the compressor is sufficient according to the detected oil content rate of the refrigerant. When it is not sufficient, an alarm can be given to remind the user to perform maintenance, so as to ensure the reliable operation of the compressor.

[0033] According to the detection method of an air-conditioning refrigerant oil content rate detection device provided by the present invention, the step of determining whether the compressor is short of oil according to the oil content rate of the refrigerant includes:

[0034] If the oil content rate of the refrigerant is lower than the set value, determine that the compressor is short of oil.

[0035] The present invention also provides an air-conditioning system, including: the above-mentioned air-conditioning refrigerant oil content rate detection device.

[0036] The air-conditioning system provided by the present invention can realize the accurate detection of the oil content rate of the refrigerant, thereby ensuring the reliable operation of the compressor, and has the characteristics of simple structure, low cost, stable and reliable, etc. Description of the Drawings

[0037] In order to more clearly illustrate the technical solutions in the present invention or related technologies, the following will briefly introduce the drawings required for use in the embodiments or the description of related technologies. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0038] Figure 1 is a schematic structural diagram of the air conditioning system provided by the present invention;

[0039] Figure 2 is an assembly schematic diagram of the air conditioning refrigerant oil content detection device provided by the present invention;

[0040] Figure 3 is a schematic flow diagram of the detection method of the air conditioning refrigerant oil content detection device provided by the present invention.

[0041] Reference numerals:

[0042] 1: Collection tank; 2: Pressure sensor; 3: First valve; 4: Second valve;

[0043] 5: Compressor; 6: Oil separator; 7: Oil return branch; 8: Cooling circuit;

[0044] 801: On-off valve; 9: Four-way valve; 10: Bypass branch; 11: Indoor heat exchanger;

[0045] 12: Outdoor heat exchanger; 13: Gas-liquid separator; 14: Indoor throttle valve;

[0046] 15: Outdoor throttle valve. Detailed embodiments

[0047] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0048] In the description of the embodiments of the present invention, it should be noted that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0049] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "coupled" 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 directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0050] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0051] The following will describe Figures 1 - 3 the air-conditioning refrigerant oil content detection device, method, and air-conditioning system of the present invention.

[0052] According to an embodiment of the first aspect of the present invention, referring to Figure 1 and Figure 2 as shown, the air-conditioning refrigerant oil content detection device provided by the present invention mainly includes components such as a collection tank 1, a pressure sensor 2, and a controller.

[0053] Among them, a first valve 3 and a second valve 4 are respectively provided at both ends of the collection tank 1 for collecting the refrigerant and refrigerant oil mixture of the compressor 5 or the oil separator 6.

[0054] The pressure sensor 2 is connected to the collection tank 1 for detecting the initial pressure and the stable pressure in the collection tank 1 at different times.

[0055] The controller is respectively connected to the first valve 3, the second valve 4, and the pressure sensor 2 for controlling the opening and closing of the first valve 3 and the second valve 4, so that the refrigerant and refrigerant oil mixture is collected in the collection tank 1, and the refrigerant oil content is obtained according to the pressure difference between the detected initial pressure and the stable pressure.

[0056] For example, during the operation of the compressor 5, the controller controls the first valve 3 to open and the second valve 4 to close. After waiting for a preset duration (for example, 5 minutes), the collection tank 1 is filled with the refrigerant and refrigerant oil mixture, and then the controller controls the first valve 3 to close. At this time, the initial pressure P1 in the collection tank 1 is detected;

[0057] Then, it is detected every 1 minute until the pressure in the collection tank 1 stabilizes, and the stable pressure P2 at this time is detected. The shortest detection duration is 30 minutes;

[0058] The pressure sensor 2 sends the detected initial pressure P1 and stable pressure P2 to the controller. The controller calculates the refrigerant oil content based on the pressure difference between the detected initial pressure P1 and stable pressure P2. Specifically:

[0059] What enters the collection tank 1 is a mixture of gaseous refrigerant and liquid refrigerant oil. After both the first valve 3 and the second valve 4 are closed, the refrigerant will gradually condense into a liquid state, and the state of the refrigerant oil will not change; at this time, the refrigerant mass M1 = ρ r *V*(P1 - P2); The mass of the refrigerant oil can be estimated as the refrigerant oil mass M2 = ρ o *V*P2 on the basis of ignoring the density difference between the refrigerant and the refrigerant oil; then the refrigerant oil content η = M2 / (M1 + M2);

[0060] Among them, M1 is the refrigerant mass, ρ r is the refrigerant density, V is the volume of the collection tank, P1 is the initial pressure, and P2 is the stable pressure; M2 is the refrigerant oil mass, ρ o is the refrigerant oil density; η is the refrigerant oil content.

[0061] Therefore, the air-conditioning refrigerant oil content detection device provided by the embodiment of the present invention can achieve accurate detection of the refrigerant oil content, thereby ensuring the reliable operation of the compressor 5, and has the characteristics of simple structure, low cost, stability and reliability, etc.

[0062] According to an embodiment of the present invention, the air-conditioning refrigerant oil content detection device of the present invention further includes: an alarm, which is connected to the controller. The controller is further used to determine whether the compressor 5 is short of oil according to the refrigerant oil content. When the compressor 5 is short of oil and still short of oil after the oil return operation, the controller controls the alarm to give an alarm.

[0063] Specifically, when the refrigerant oil content η is lower than the set value (for example, 60% can be taken), it is determined that the compressor 5 is short of oil. At this time, the compressor 5 is controlled to perform an oil return action. The oil return action of the compressor 5 is a conventional technology in the art and will not be elaborated here; after the oil return action is completed, the refrigerant oil content η is detected again. If the detected refrigerant oil content η is still lower than the set value, that is, when the compressor 5 is still short of oil, an alarm message is sent at this time to remind the user to maintain.

[0064] Therefore, the air-conditioning refrigerant oil content detection device of the embodiment of the present invention can also judge whether the refrigerant oil in the compressor 5 is sufficient according to the detected refrigerant oil content. When it is insufficient, an alarm can be given to remind the user to perform maintenance, so as to further ensure the reliable operation of the compressor 5.

[0065] According to an embodiment of the present invention, with reference to Figure 1 As shown, the collection tank 1 is connected in parallel to the oil return branch 7 between the oil outlet of the oil separator 6 and the suction port of the compressor 5.

[0066] Specifically, the gaseous refrigerant and refrigerant oil mixture discharged from the compressor 5 enter the oil separator 6 for separation. A part of the separated gaseous refrigerant flows into the four-way valve 9, and the other part of the gaseous refrigerant and refrigerant oil mixture enter the compressor 5 through the oil return branch 7. And when the first valve 3 is opened and the second valve 4 is closed, the other part of the gaseous refrigerant and refrigerant oil mixture can also enter the collection tank 1 for collection and detection.

[0067] According to an embodiment of the present invention, with reference to Figure 1 As shown, the collection tank 1 is a heat exchange type collection tank. The collection tank 1 is connected in parallel to the fourth valve port of the four-way valve 9 and the suction port of the compressor 5 through the cooling circuit 8. Specifically, the cooling circuit 8 is connected in parallel to the fourth valve port of the four-way valve 9 and the inlet of the gas-liquid separator 13, and a on-off valve 801 is provided in the cooling circuit 8 to control the on-off of the cooling circuit 8.

[0068] Since the cooling rate of the refrigerant in the collection tank 1 is relatively slow, at this time, the on-off valve 801 can be controlled to open. A part of the low-temperature refrigerant discharged from the fourth valve port of the four-way valve 9 can flow into the collection tank 1 through the cooling circuit 8 for cooling. The heat-exchanged refrigerant and another part of the low-temperature refrigerant discharged from the fourth valve port of the four-way valve 9 flow together to the gas-liquid separator 13 for gas-liquid separation.

[0069] Therefore, the embodiment of the present invention can use the low-temperature refrigerant of the air-conditioning system to cool the collection tank 1, accelerate the condensation process of the refrigerant in the collection tank 1, thereby improving the detection efficiency, and realizing the full utilization of energy.

[0070] There is no special limitation on the specific type of the collection tank 1 of the present invention. For example, it can be of the type of expansion tube heat exchanger, shell-and-tube heat exchanger, plate heat exchanger, etc.

[0071] And, there is no special limitation on the specific types of the first valve 3 and the second valve 4 of the present invention. For example, they can be solenoid valves.

[0072] According to an embodiment of the present invention, with reference to Figure 2 As shown, the collection tank 1 can also be directly connected to the compressor 5 through the bypass branch 10 for collecting the refrigerant and refrigerant oil mixture in the compressor 5.

[0073] Next, the detection method of the air-conditioning refrigerant oil content detection device provided by the present invention will be described. The detection method of the air-conditioning refrigerant oil content detection device described below can be mutually corresponding and referred to with the air-conditioning refrigerant oil content detection device described above.

[0074] According to an embodiment of the second aspect of the present invention, referring to Figure 3 as shown, the present invention further provides a detection method for the oil content rate of the air-conditioning refrigerant in the above embodiment, which mainly includes the following steps:

[0075] S100. During the operation of the compressor 5, control the first valve 3 to open and the second valve 4 to close. After waiting for a preset time period, control the first valve 3 to close, so that the collection tank 1 collects the refrigerant and refrigerating oil mixture of the compressor 5 or the oil separator 6;

[0076] S200. Detect the initial pressure and the stable pressure at different times in the collection tank 1 through the pressure sensor 2;

[0077] S300. Obtain the oil content rate of the refrigerant according to the pressure difference between the detected initial pressure and the stable pressure.

[0078] Therefore, the detection method for the oil content rate of the air-conditioning refrigerant provided by the embodiment of the present invention can achieve accurate detection of the oil content rate of the refrigerant, thereby ensuring the reliable operation of the compressor.

[0079] According to an embodiment of the present invention, the step of obtaining the oil content rate of the refrigerant according to the pressure difference between the detected initial pressure and the stable pressure includes:

[0080] Determine the refrigerant mass and the refrigerating oil mass according to the pressure difference;

[0081] Obtain the oil content rate of the refrigerant according to the refrigerant mass and the refrigerating oil mass, specifically including:

[0082] M1 = ρ r *V*(P1 - P2);

[0083] M2 = ρ o *V*P2;

[0084] η = M2 / (M1 + M2);

[0085] Wherein, M1 is the refrigerant mass, ρ r is the refrigerant density, V is the volume of the collection tank, P1 is the initial pressure, P2 is the stable pressure; M2 is the refrigerating oil mass, ρ o is the refrigerating oil density; η is the oil content rate of the refrigerant.

[0086] According to an embodiment of the present invention, referring to Figure 3 as shown, the detection method for the air-conditioning refrigerant oil content rate detection device of the present invention further includes the step:

[0087] S400. Determine whether the compressor 5 is short of oil according to the oil content rate of the refrigerant. When the compressor 5 is short of oil and after the oil return operation, when the compressor 5 is still short of oil, control the alarm to alarm.

[0088] Therefore, the detection method of the air-conditioning refrigerant oil content detection device according to the embodiment of the present invention can also determine whether the refrigeration oil in the compressor 5 is sufficient according to the detected refrigerant oil content. When it is insufficient, an alarm can be given to remind the user to perform maintenance, so as to further ensure the reliable operation of the compressor 5.

[0089] According to an embodiment of the present invention, the step of determining whether the compressor 5 is short of oil according to the refrigerant oil content includes:

[0090] If the refrigerant oil content is lower than the set value, it is determined that the compressor 5 is short of oil.

[0091] The following further describes the detection method of the air-conditioning refrigerant oil content detection device provided by the present invention with a specific example, which generally includes:

[0092] (1) Detect the pressure difference: During the operation of the compressor 5, control the first valve 3 to open and the second valve 4 to close. After waiting for 5 minutes, the collection tank 1 is filled with a mixture of refrigerant and refrigeration oil. Control the first valve 3 to close, and then start to detect the initial pressure P1 in the collection tank 1; then detect it once every 1 minute until the pressure in the collection tank 1 is stable and unchanged, and detect the stable pressure P2 at this time. The shortest detection duration is 30 minutes.

[0093] (2) Calculate the refrigerant oil content: What enters the collection tank 1 is gaseous refrigerant and liquid refrigeration oil. After the first valve 3 and the second valve 4 are both closed, the refrigerant will gradually condense into a liquid state, and the state of the refrigeration oil will not change; at this time, the refrigerant mass M1 = ρ r *V*(P1 - P2); based on ignoring the density difference between the refrigerant and the refrigeration oil, the refrigeration oil mass can be estimated as the refrigeration oil mass M2 = ρ o *V*P2; then the refrigerant oil content η = M2 / (M1 + M2).

[0094] (3) Oil shortage determination: When the refrigerant oil content η is lower than 60%, it is determined that the compressor 5 is short of oil. At this time, control the compressor 5 to perform an oil return operation; after the oil return operation is completed, detect the refrigerant oil content η again. If the detected refrigerant oil content η is still lower than 60%, that is, when the compressor 5 is still short of oil, an alarm message is sent at this time to remind the user to perform maintenance.

[0095] Therefore, the embodiment of the present invention can calculate the refrigerant oil content according to the pressure difference before and after in the collection tank 1, so as to determine whether the refrigeration oil in the compressor 5 is sufficient according to the refrigerant oil content, and further can effectively ensure the reliable operation of the compressor 5.

[0096] According to the embodiment of the third aspect of the present invention, as shown in Figure 1 the present invention also provides an air-conditioning system, which mainly includes: the air-conditioning refrigerant oil content detection device of the above embodiment.

[0097] Since the air-conditioning system according to the embodiment of the present invention includes the air-conditioning refrigerant oil content detection device of the above embodiment, it has all the technical effects of the air-conditioning refrigerant oil content detection device of the above embodiment, which will not be elaborated here.

[0098] According to an embodiment of the present invention, the air-conditioning system of the present invention further includes: a compressor 5, an oil separator 6, a four-way valve 9, an indoor heat exchanger 11, and an outdoor heat exchanger 12. Among them, the exhaust port of the compressor 5 is connected to the inlet of the oil separator 6, the gas outlet of the oil separator 6 is connected to the first valve port of the four-way valve 9, the second valve port of the four-way valve 9 is connected to the indoor heat exchanger 11, the third valve port of the four-way valve 9 is connected to the outdoor heat exchanger 12, the fourth valve port of the four-way valve 9 is connected to the suction port of the compressor 5, and the indoor heat exchanger 11 is connected to the outdoor heat exchanger 12.

[0099] According to an embodiment of the present invention, the fourth valve port of the four-way valve 9 is connected to the suction port of the compressor 5 through a gas-liquid separator 13.

[0100] According to an embodiment of the present invention, the indoor heat exchanger 11 is provided with an indoor throttle valve 14, and the outdoor heat exchanger 12 is provided with an outdoor throttle valve 15. The indoor throttle valve 14 and the outdoor throttle valve 15 are located in the liquid pipe between the indoor heat exchanger 11 and the outdoor heat exchanger 12, mainly playing a throttling role.

[0101] Moreover, a plurality of indoor heat exchangers 11 are arranged in parallel to improve the indoor heat exchange effect.

[0102] The working principle of the air-conditioning system of the present invention will be described below, mainly including the refrigeration mode and the heating mode.

[0103] Refrigeration mode: The gaseous refrigerant and refrigerating oil generated by the compressor 5 are discharged into the oil separator 6 for separation. A part of the separated gaseous refrigerant flows through the first valve port and the third valve port of the four-way valve 9 to the outdoor heat exchanger 12 for condensation and heat release. Another part of the gaseous refrigerant and refrigerating oil enter the compressor 5 through the oil return branch 7. And when the first valve 3 is opened and the second valve 4 is closed, another part of the gaseous refrigerant and refrigerating oil can also enter the collection tank 1 for collection and detection. The specific detection process is as described above; the condensed refrigerant is throttled by the outdoor throttle valve 15 and the indoor throttle valve 14 and then enters the indoor heat exchanger 11 for evaporation and heat absorption, and then flows through the second valve port and the fourth valve port of the four-way valve 9 into the gas-liquid separator 13 for gas-liquid separation. The separated gaseous refrigerant flows back to the compressor 5.

[0104] Heating mode: The gaseous refrigerant and refrigerating oil generated by the compressor 5 are discharged into the oil separator 6 for separation. A part of the separated gaseous refrigerant flows through the first valve port and the second valve port of the four-way valve 9 to the indoor heat exchanger 11 for condensation and heat release. Another part of the gaseous refrigerant and the refrigerating oil enter the compressor 5 through the oil return branch 7. And when the first valve 3 is opened and the second valve 4 is closed, another part of the gaseous refrigerant and the refrigerating oil can also enter the collection tank 1 for collection and detection. For the specific detection process, refer to the foregoing; the condensed refrigerant throttles through the indoor throttle valve 14 and the outdoor throttle valve 15 and then enters the outdoor heat exchanger 12 for evaporation and heat absorption, and then flows through the third valve port and the fourth valve port of the four-way valve 9 into the gas-liquid separator 13 for gas-liquid separation. The separated gaseous refrigerant flows back to the compressor 5.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An air conditioner refrigerant oil content detection device, characterized in that, it includes: A collection tank, with a first valve and a second valve provided at both ends of the collection tank, for collecting the refrigerant and refrigerant oil mixture of the compressor or the oil separator; A pressure sensor, connected to the collection tank, for detecting the initial pressure and the stable pressure at different times inside the collection tank; A controller, respectively connected to the first valve, the second valve and the pressure sensor, for controlling the opening and closing of the first valve and the second valve, and obtaining the refrigerant oil content according to the pressure difference between the detected initial pressure and the stable pressure.

2. The air conditioner refrigerant oil content detection device according to claim 1, characterized in that, it further includes: An alarm, connected to the controller, and the controller is further used to determine whether the compressor is short of oil according to the refrigerant oil content. When the compressor is short of oil and still short of oil after an oil return operation, the controller controls the alarm to give an alarm.

3. The air conditioner refrigerant oil content detection device according to claim 1, characterized in that, The collection tank is connected in parallel to the oil return branch between the oil outlet of the oil separator and the suction port of the compressor.

4. The air conditioner refrigerant oil content detection device according to claim 3, characterized in that, The collection tank is a heat exchange type collection tank, and the collection tank is connected in parallel to the fourth valve port of the four-way valve and the suction port of the compressor through a cooling circuit.

5. The air conditioner refrigerant oil content detection device according to claim 1, characterized in that, The collection tank is connected to the compressor through a bypass branch.

6. A detection method for the air conditioner refrigerant oil content detection device according to any one of claims 1-5, characterized in that, it includes: During the operation of the compressor, control the first valve to open and the second valve to close. After waiting for a preset time, control the first valve to close, so that the collection tank collects the refrigerant and refrigerant oil mixture of the compressor or the oil separator; Detect the initial pressure and the stable pressure at different times inside the collection tank through the pressure sensor; Obtain the refrigerant oil content according to the pressure difference between the detected initial pressure and the stable pressure.

7. The detection method for the air conditioner refrigerant oil content detection device according to claim 6, characterized in that, The step of obtaining the refrigerant oil content according to the pressure difference between the detected initial pressure and the stable pressure includes: Determine the refrigerant mass and the refrigerant oil mass according to the pressure difference; Obtain the refrigerant oil content according to the refrigerant mass and the refrigerant oil mass.

8. The detection method for the air conditioner refrigerant oil content detection device according to claim 7, characterized in that, The step of obtaining the refrigerant oil content according to the refrigerant mass and the refrigerant oil mass includes: M1 = ρ r *V*(P1 - P2); M2 = ρ o *V*P2; η = M2 / (M1 + M2); Among them, M1 is the mass of the refrigerant, ρ r is the density of the refrigerant, V is the volume of the collection tank, P1 is the initial pressure, and P2 is the stable pressure; M2 is the mass of the refrigeration oil, ρ o is the density of the refrigeration oil; η is the oil content rate of the refrigerant.

9. The detection method for the air conditioner refrigerant oil content detection device according to claim 6, characterized in that, it further includes: Determine whether the compressor is short of oil according to the refrigerant oil content. When the compressor is short of oil and still short of oil after an oil return operation, control the alarm to give an alarm.

10. The detection method of the oil content rate of the air-conditioning refrigerant in the detection device according to claim 9, characterized in that, the step of determining whether the compressor is short of oil according to the oil content rate of the refrigerant includes: if the oil content rate of the refrigerant is lower than the set value, it is determined that the compressor is short of oil.

11. An air-conditioning system, characterized in that, it includes: the air-conditioning refrigerant oil content rate detection device according to any one of claims 1-5.

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