Oil return monitoring device, air conditioning system and oil return control method thereof

Abstract

The present application relates to an oil return monitoring device, an air conditioning system and an oil return control method thereof. The oil return monitoring device comprises: a housing, an oil inlet pipe, an oil outlet pipe and a monitoring component. The housing has an oil storage chamber for buffering oil, the oil inlet pipe is arranged in the housing, and has a connected oil inlet and an oil inlet outlet, the oil inlet is used to be connected to the oil outlet side of the oil separator, and the oil inlet outlet is connected to the oil storage chamber. The oil outlet pipe is arranged in the housing, and has a connected oil inlet and an oil outlet, the oil inlet is connected to the oil storage chamber, and the oil outlet is used to be connected to the suction side of the compressor. The monitoring component is provided with a housing, which is used to obtain the oil level characteristics of the oil storage chamber, and judge whether the oil separator is effectively returning oil according to the oil level characteristics. By judging the oil level characteristics in the oil storage chamber, it is possible to judge whether the oil separator is effectively returning, which can avoid the risk of damage to the compressor due to lack of oil when the oil separator cannot effectively return.

Description

Technical Field

[0001] The present application relates to the technical field of air-conditioning equipment, and in particular to an oil return monitoring device, an air-conditioning system and an oil return control method thereof. Background Art

[0002] In the air conditioning system, a certain amount of lubricating oil must be ensured in the compressor to stabilize the operation of the compressor. During the operation of the compressor, the lubricating oil in it will be discharged from the compressor along with the refrigerant, and will flow through and partially remain in the refrigerant channels in the oil separator, outdoor unit heat exchanger, electromagnetic expansion valve, indoor unit heat exchanger and other system components. In order to return the lubricating oil to the compressor, an oil separator is generally set on the exhaust side of the compressor. The oil separator separates the lubricating oil from the refrigerant and controls the return of the lubricating oil to the compressor by opening and closing the oil return solenoid valve. The existing air conditioning system only controls the opening and closing of the oil return solenoid valve, but cannot determine whether the oil separator effectively returns oil (effective means that oil returns to the compressor). When there is no oil or little oil in the oil separator, there is little or no lubricating oil returned to the compressor, which can easily cause the compressor to run without oil, directly affecting the life of the compressor. Summary of the invention

[0003] In order to solve the oil shortage problem of the compressor caused by the inability of the existing air-conditioning system to determine whether the oil separator is effectively returning oil, the present application proposes an oil return monitoring device, an air-conditioning system and an oil return control method thereof. The oil return monitoring device, the air-conditioning system and the oil return control method thereof have the technical effect of being able to determine whether the oil separator is effectively returning oil and reducing the probability of the compressor running out of oil.

[0004] An oil return monitoring device, comprising:

[0005] The housing has an oil storage cavity for caching oil;

[0006] An oil inlet pipe is provided on the housing and has an oil inlet and an oil inlet outlet which are connected to each other, wherein the oil inlet is used to be connected to the oil outlet side of the oil separator, and the oil inlet outlet is connected to the oil storage chamber;

[0007] an oil outlet pipe, disposed on the housing, and having an oil inlet and an oil outlet connected to each other, the oil inlet being connected to the oil storage chamber, and the oil outlet being used to be connected to the suction side of the compressor; and

[0008] A monitoring component is arranged on the housing and is used to obtain the oil level characteristics of the oil storage cavity and determine whether the oil separator effectively returns oil according to the oil level characteristics.

[0009] In one of the embodiments, in the direction of gravity, the oil inlet and outlet are arranged higher than the bottom wall of the oil storage cavity.

[0010] In one of the embodiments, one end of the oil inlet pipe having the oil inlet and outlet passes through the bottom wall of the oil storage cavity and extends toward the inner wall portion of the oil storage cavity that is higher than the oil inlet and outlet.

[0011] In one embodiment, the oil inlet pipe is provided with an oil return hole on the pipe body located in the oil storage chamber, and the oil return hole connects the oil inlet pipe and the oil storage chamber;

[0012] In the gravity direction, the oil return hole is arranged closer to the bottom wall of the oil storage cavity than the oil inlet and outlet.

[0013] In one of the embodiments, the oil return hole includes a first oil return hole and a second oil return hole, and the first oil return hole is arranged closer to the bottom wall of the oil storage cavity than the second oil return hole.

[0014] In one embodiment, the diameter of the first oil return hole is smaller than the diameter of the second oil return hole.

[0015] In one embodiment, the monitoring assembly includes a sensing member, a floating member, and a control member;

[0016] The floating member is arranged in the oil storage chamber and can float along with the oil in the oil storage chamber in the direction of gravity; the sensing member is arranged in the housing and can sense the floating member within a set range, and the sensing member generates an electrical signal as a first oil level characteristic when sensing the floating member, and generates an electrical signal as a second oil level characteristic when not sensing the floating member;

[0017] The control component is communicatively connected with the sensing component, and is used to determine whether the oil separator effectively returns oil based on the first oil level characteristic, and is used to determine whether the oil separator does not effectively return oil based on the second oil level characteristic.

[0018] In one embodiment, a limiting portion is provided on the side wall of the oil storage chamber, and the floating member floats between the limiting portion and the bottom wall of the oil storage chamber; the limiting portion is arranged corresponding to the set range to prevent the floating member from floating to a position exceeding the set range.

[0019] In one embodiment, the limiting portion is lower than the oil inlet and outlet.

[0020] An air conditioning system comprises a compressor, an oil return solenoid valve, an oil return separator, and the oil return monitoring device described in any one of the above embodiments, wherein the oil inlet side of the oil return separator is connected to the exhaust side of the compressor, the oil return solenoid valve is connected to the oil outlet side of the oil return separator and the oil inlet of the oil return monitoring device, and the oil outlet of the oil return monitoring device is connected to the intake side of the compressor.

[0021] An oil return control method for an air conditioning system, comprising:

[0022] Obtaining oil level characteristics in the oil storage cavity;

[0023] When the oil level characteristic indicates that the oil level in the oil storage chamber is higher than or equal to the preset oil level, it is determined that the oil separator effectively returns oil;

[0024] When the oil level characteristic indicates that the oil level in the oil storage chamber is lower than the preset oil level, it is determined that the oil separator does not effectively return oil.

[0025] In one embodiment, after the step of determining that the oil separator effectively returns oil, the method further includes:

[0026] Keep the oil return solenoid valve open;

[0027] After the step of determining that the oil separator does not effectively return oil, the method further includes:

[0028] Controlling the oil return of the air conditioning system, when the oil return of the air conditioning system is completed, the oil return solenoid valve is closed, the compressor in the air conditioning system operates at a preset maximum frequency, and all valves in the air conditioning system except the oil return solenoid valve are adjusted to a preset maximum opening.

[0029] In one embodiment, the step of obtaining the oil level characteristics in the oil storage cavity specifically includes:

[0030] When the oil return solenoid valve is in an open state, determining whether the air conditioning system returns oil;

[0031] If yes, wait for a set time and then obtain the oil level characteristics in the oil storage cavity;

[0032] If not, obtain the oil level characteristics in the oil storage cavity.

[0033] The above-mentioned oil return monitoring device has an oil inlet connected to the oil outlet side of the oil separator, and an oil outlet connected to the suction side of the compressor. When the oil return solenoid valve is opened, the discharge from the oil outlet side of the oil separator (pure lubricating oil, a mixture of lubricating oil and gaseous refrigerant, or pure gaseous refrigerant) enters the oil inlet pipe through the oil inlet. When the content of lubricating oil entering the oil storage chamber is less than the amount of lubricating oil flowing out through the oil outlet, the oil level in the oil storage chamber gradually decreases, indicating that the oil separator has not effectively returned oil. When the discharge of the oil separator is pure gaseous refrigerant, the content of lubricating oil entering the oil storage chamber is less than the amount of lubricating oil flowing out through the oil outlet, and the oil level in the oil storage chamber gradually decreases, indicating that the oil separator has not effectively returned oil. Compared with the prior art, by judging the oil level characteristics in the oil storage chamber, it is possible to judge whether the oil separator is effectively refluxed, thereby avoiding the risk of damage to the compressor due to lack of oil when the oil separator cannot effectively reflux. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a three-dimensional diagram of an oil return monitoring device in one embodiment of the present application;

[0035] Figure 2 for Figure 1 The internal structure diagram of the oil return monitoring device shown;

[0036] Figure 3 for Figure 1 A schematic diagram of the internal structure of a portion of the structure of the oil return monitoring device shown;

[0037] Figure 4 for Figure 1 The internal structure diagram of the oil return monitoring device in the first state is shown;

[0038] Figure 5 for Figure 1 The internal structure diagram of the oil return monitoring device in the second state is shown;

[0039] Figure 6 for Figure 1 The schematic diagram of the oil return monitoring device in the first working condition is shown;

[0040] Figure 7 for Figure 1 The schematic diagram of the oil return monitoring device in the second working condition is shown;

[0041] Figure 8 for Figure 1 The schematic diagram of the oil return monitoring device in the third working condition is shown;

[0042] Fig. 9 is a three-dimensional diagram of a floating member in an embodiment of the present application;

[0043] Fig.10 for Fig. 9 A front view of the floating member shown;

[0044] Fig.11 is a system diagram of an air conditioning system in an embodiment of the present application;

[0045] Fig.12 Schematic diagram of the flow of the oil return control method in one embodiment of the present application.

[0046] Description of reference numerals:

[0047] 100. Oil return monitoring device;

[0048] 110, housing; 111, oil storage chamber; 112, limiting portion;

[0049] 120, oil inlet pipe; 121, oil inlet outlet; 122, oil inlet inlet; 123, oil return hole; 1231, first oil return hole; 1232, second oil return hole;

[0050] 130, oil outlet pipe; 131, oil outlet; 132, oil inlet;

[0051] 140, monitoring component; 141, floating part; 1411, floating ring; 1412, metal sheet; 142, sensing part;

[0052] 200, compressor; 300, oil separator; 400, oil return solenoid valve; 500, oil return capillary; 600, outdoor heat exchanger; 700, indoor heat exchanger; 800, gas-liquid separator; 900, solenoid expansion valve. DETAILED DESCRIPTION

[0053] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0054] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships 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 referred device or element 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.

[0055] In addition, 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. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0056] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0057] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0058] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0059] To facilitate understanding, the flow direction of lubricating oil in the air conditioning system is first introduced. The compressor discharges a mixture of refrigerant and lubricating oil; part of it is separated by the oil separator, and then passes through the oil return solenoid valve and the oil return capillary tube back to the suction side of the compressor. The lubricating oil that has not been separated enters other system components in the air conditioning system together with the refrigerant. A small part of it flows back to the compressor with the refrigerant, and the rest will adhere to the inner walls of other system components and continue to accumulate until most of the lubricating oil remains on the inner walls of other system components. At this time, the lubricating oil in the compressor and the oil separator is getting less and less, and there is a lack of oil.

[0060] When there is sufficient oil in the compressor, the amount of lubricating oil separated by the oil separator is also relatively sufficient. Liquid lubricating oil flows out from the oil outlet side of the oil separator. At this time, a stable amount of lubricating oil can flow back to the compressor. As the system runs, lubricating oil accumulates on the inner walls of other system components, the amount of oil in the compressor decreases, and the lubricating oil separated by the oil separator is insufficient. At this time, a mixture of gaseous refrigerant and lubricating oil flows out from the oil outlet side of the oil separator. When the lubricating oil in the compressor is seriously insufficient, there is basically no lubricating oil separated by the oil separator. At this time, all the gaseous refrigerant flows out from the oil outlet side of the oil separator. When there is sufficient lubricating oil in the oil separator to flow back into the compressor, it indicates that the oil separator can effectively return oil. When there is no lubricating oil or only a small amount of lubricating oil in the oil separator, it indicates that the oil separator has not effectively returned oil. The oil return monitoring device provided in the present application can monitor whether the oil separator effectively returns oil.

[0061] See also Figure 1 , Figure 2 and Figure 3 In one embodiment of the present application, an oil return monitoring device 100 is provided, comprising a housing 110, an oil inlet pipe 120, an oil outlet pipe 130 and a monitoring component 140. The housing 110 has an oil storage chamber 111 for buffering oil. The oil inlet pipe 120 is arranged on the housing 110 and has a connected oil inlet 122 and an oil inlet outlet 121. The oil inlet 122 is used to connect to the oil outlet side of the oil separator 300, and the oil inlet outlet 121 is connected to the oil storage chamber 111. The oil outlet pipe 130 is arranged on the housing 110 and has a connected oil inlet 132 and an oil outlet 131. The oil inlet 132 is connected to the oil storage chamber 111, and the oil outlet 131 is used to connect to the suction side of the compressor 200. The monitoring component 140 is arranged on the housing 110, and is used to obtain the oil level characteristics of the oil storage chamber 111, and judge whether the oil separator 300 effectively returns oil according to the oil level characteristics.

[0062] In actual operation of the above-mentioned oil return monitoring device 100, the oil inlet 122 is connected to the oil outlet side of the oil separator 300, and the oil outlet 131 is connected to the suction side of the compressor 200. The oil return solenoid valve 400 is opened, and the discharge (pure lubricating oil, a mixture of lubricating oil and gaseous refrigerant, or pure gaseous refrigerant) on the oil outlet side of the oil separator 300 enters the oil inlet pipe 120 through the oil inlet 122.

[0063] When the discharge from the oil separator 300 is pure lubricating oil (see Figure 6), since the lubricating oil is sufficient, the amount of lubricating oil entering the oil storage chamber 111 is greater than the amount of oil flowing out of the oil storage chamber 111 through the oil inlet 132, and the lubricating oil gradually fills the oil storage chamber 111. As the lubricating oil continues to flow in, the content of the lubricating oil flowing into the oil storage chamber 111 and the content of the lubricating oil flowing out through the oil outlet 131 can be kept in balance, so that the oil level in the oil storage chamber 111 remains basically unchanged, indicating that the oil separator 300 effectively returns oil. At this time, the oil separator 300 has sufficient lubricating oil to flow back to the compressor 200.

[0064] When the discharge of the oil separator 300 is an oil-liquid mixture (see Figure 7 ), and when the lubricating oil content entering the oil storage chamber 111 is greater than or equal to the amount of lubricating oil flowing out through the oil outlet 131, the oil level in the oil storage chamber 111 remains unchanged or increases, indicating that the oil separator 300 effectively returns oil. When the lubricating oil content entering the oil storage chamber 111 is less than the amount of lubricating oil flowing out through the oil outlet 131, the oil level in the oil storage chamber 111 gradually decreases, indicating that the oil separator 300 does not effectively return oil.

[0065] When the discharge from the oil separator 300 is pure gaseous refrigerant (see Figure 8 ), the lubricating oil content entering the oil storage chamber 111 is less than the amount of lubricating oil flowing out through the oil outlet 131, and the oil level in the oil storage chamber 111 gradually decreases, indicating that the oil separator 300 does not effectively return oil. The monitoring component 140 is used to obtain the oil level characteristics in the oil storage chamber 111.

[0066] According to the oil level characteristics, it can be determined whether the oil separator 300 effectively returns oil. When the oil level characteristics indicate that the oil level is not lower than the preset oil level, it can be determined that the oil separator 300 effectively returns oil. When the oil level characteristics indicate that the oil level is lower than the preset oil level, it can be determined that the oil separator 300 does not effectively return oil.

[0067] Compared with the prior art, the above-mentioned oil return monitoring device 100 can determine whether the oil separator 300 is effectively refluxed by judging the oil level characteristics in the oil storage chamber 111, thereby avoiding the risk of damage to the compressor 200 due to lack of oil when the oil separator 300 cannot effectively reflux.

[0068] When it is determined that the oil separator 300 does not effectively return oil, the air conditioning system will return oil. When the air conditioning system returns oil, the oil return solenoid valve 400 is closed, the compressor 200 runs at the preset maximum frequency, and the valve openings of the air conditioning system except the oil return solenoid valve 400 are adjusted to the maximum to flush the accumulated oil in the air conditioning system pipeline into the oil separator 300 and the compressor 200 oil pool. At this time, the oil separator 300 stores a sufficient amount of lubricating oil. It should be noted that when the system refluxes, the temperature difference between the indoor heat exchanger 700 and the outdoor heat exchanger 600 of the air conditioning system will be neutralized, resulting in the air conditioning system being unable to effectively cool or heat, wasting energy, so the number of system oil returns should be reduced.

[0069] In this embodiment, whether the oil separator 300 effectively returns oil is determined based on the oil level characteristics, specifically, whether the oil level in the oil storage chamber 111 is lower than a preset oil level, and the preset oil level is greater than zero. In order to avoid the situation where the oil separator 300 has sufficient lubricating oil, when the oil level in the oil storage chamber 111 is lower than the preset oil level in the early stage of the lubricating oil flowing into the oil storage chamber 111, it is misjudged that the oil return separator 300 does not effectively return oil, that is, it is misjudged that the compressor 200 is short of oil, causing the system to return oil again. It is required that when the monitoring component 140 starts to monitor the oil level changes in the storage chamber, the storage chamber needs to have a preset oil level of oil buffered in it.

[0070] In order to store the amount of oil at a preset oil level in the storage chamber, in a preferred embodiment, when the oil return solenoid valve 400 is opened for the first time after the system returns oil, the monitoring component 140 starts to obtain the oil level characteristics of the oil storage chamber 111 after waiting for a preset time. The monitoring component 140 starts to monitor the oil level of the oil storage chamber 111 after the preset time after the oil return solenoid valve 400 is opened for the first time after the system returns oil. This can avoid the oil return separator 300 being misjudged as not effectively returning oil to the compressor 200 due to the oil level being lower than the preset oil level during the oil buffering process, resulting in the system returning oil again. In this way, the monitoring results are ensured to be accurate, the system can avoid multiple oil returns, and the system energy efficiency can be improved. Of course, in other embodiments, when installing the oil return device, the amount of oil at a certain oil level can be manually pre-stored in the oil storage chamber 111. Alternatively, the oil level in the oil storage chamber 111 is measured by an additional oil level gauge. When the oil level in the oil storage chamber 111 reaches a preset oil level, the monitoring component 140 starts monitoring and obtains the oil level characteristics of the oil storage chamber 111 .

[0071] It should be noted that the refrigerant entering the oil separator 300 is a high-pressure refrigerant. Under the action of the high-pressure refrigerant, the lubricating oil enters the oil storage chamber 111. That is to say, the discharge of the oil separator 300 will not flow back to the oil separator 300 through the oil inlet pipe 120. Therefore, in this embodiment, the position of the oil inlet outlet 121 is not limited, and can be lower than the oil inlet 132, and can be not lower than the oil inlet 132.

[0072] After the lubricating oil enters the oil storage chamber 111, a certain amount of oil is buffered in the oil storage chamber 111. There are many schemes for buffering the lubricating oil in the oil storage chamber 111. One example is that the oil inlet and outlet 132 is located at the bottom of the oil storage chamber 111, and the flow area of ​​the oil inlet pipe 120 is larger than the flow area of ​​the oil outlet pipe 130. When the discharge is pure lubricating oil, the amount of lubricating oil entering the oil storage chamber 111 is larger than the amount of lubricating oil flowing out of the oil storage chamber 111, so that the oil storage chamber 111 gradually buffers the lubricating oil.

[0073] In some embodiments, see Figure 4 and Figure 5 , in the direction of gravity, the oil inlet and outlet 132 is arranged higher than the bottom wall of the oil storage chamber 111. At this time, since the oil inlet and outlet 132 is arranged higher than the bottom wall of the oil storage chamber 111, the discharge of the oil separator 300 flows into the oil storage chamber 111 through the air intake pipe and the oil inlet and outlet 121, and can gradually accumulate from the bottom wall of the oil storage chamber 111, and the oil level gradually rises. When the oil level reaches the height of the oil inlet and outlet 132, the lubricating oil flows from the oil storage chamber 111 to the suction side of the compressor 200. Specifically, the oil inlet and outlet 132 can be located on the top wall or side wall of the oil outlet chamber. Of course, it is also possible that one end of the oil outlet pipe 130 having the oil inlet and outlet 132 extends into the oil storage chamber 111, so that the oil inlet and outlet 132 is higher than the bottom wall of the oil storage chamber 111, which is convenient for caching the lubricating oil.

[0074] For details about the embodiments, please refer to Figure 4 and Figure 5 , one end of the oil inlet pipe 120 with the oil inlet and outlet 121 passes through the bottom wall of the oil storage chamber 111, and extends toward the inner wall portion of the oil storage chamber 111 that is higher than the oil inlet and outlet 132. In actual operation, when the oil-gas mixture enters the oil storage chamber 111, the oil level in the oil storage chamber 111 will gradually drop to below the oil inlet and outlet 132. At this time, after the oil-gas mixture flows out of the oil inlet and outlet 121 driven by the gaseous refrigerant, it will directly collide with the inner wall portion of the oil storage chamber 111 that is higher than the oil inlet and outlet 132, so that the lubricating oil in the oil-gas mixture exists in the form of atomized oil. Compared with oil droplets, the atomized oil can flow out of the oil storage chamber 111 through the oil inlet and outlet 132 quickly with the gaseous refrigerant. In this way, not only the oil return speed of the lubricating oil is accelerated, but also the amount of oil flowing out of the oil storage chamber 111 with the gaseous refrigerant can be increased.

[0075] It should be noted that "the inner wall portion higher than the oil inlet and outlet 132" refers to the inner wall portion whose distance to the bottom wall of the oil storage chamber 111 is greater than the distance from the oil inlet and outlet 132 to the bottom wall of the oil storage chamber 111, which can be the top wall of the oil storage chamber 111 or the side wall of the oil storage chamber 111. The side wall refers to the inner wall connecting the bottom wall and the top wall. Preferably, one end of the oil inlet pipe 120 having the oil inlet and outlet 121 extends toward the top wall of the oil storage chamber 111 along the direction of gravity. At this time, the length of the oil inlet end in the oil storage chamber 111 is shorter, which is conducive to accelerating the generation of atomized oil.

[0076] For further details on the embodiments, please refer to Figure 4 and Figure 5 , the distance from the oil inlet outlet 121 to the top wall of the oil storage chamber 111 is smaller than the distance from the oil inlet outlet 121 to the bottom wall of the oil storage chamber 111. In this way, the oil-gas mixture sprayed through the oil inlet outlet 121 can quickly collide with the inner wall of the oil storage chamber 111 to form atomized oil, thereby accelerating the generation of atomized oil.

[0077] For further details on the embodiments, please refer to Figure 4 and Figure 5 , the distance from the oil inlet 132 to the top wall of the oil storage chamber 111 is smaller than the distance from the oil inlet 121 to the bottom wall of the oil storage chamber 111. In this way, the generated atomized oil can enter the oil inlet 132 through a shorter distance, speeding up the lubricating oil return speed and increasing the lubricating oil return amount.

[0078] Specifically in the embodiment, the oil inlet pipe 120 is provided with an oil return hole 123 on the pipe body in the oil storage chamber 111, and the oil return hole 123 connects the oil inlet pipe 120 and the oil storage chamber 111. In the gravity direction, the oil return hole 123 is arranged closer to the bottom wall of the oil storage chamber 111 than the oil inlet 132.

[0079] During actual operation, when the oil level in the oil storage chamber 111 is lower than the oil inlet 132 and the substance entering the oil storage chamber 111 includes gaseous refrigerant, based on the Venturi principle, the lubricating oil in the oil storage chamber 111 will flow back into the intake pipe through the oil return hole 123, and return to the compressor 200 driven by the gaseous refrigerant, thereby increasing the oil return amount of the compressor 200 and also improving the utilization rate of the lubricating oil.

[0080] For further information, see Figure 3 , Figure 4 and Figure 5 The oil return hole 123 includes a first oil return hole 1231 and a second oil return hole 1232. The first return hole is arranged closer to the bottom wall of the oil storage chamber 111 than the second oil return hole 1232. In actual operation, when the oil level in the oil storage chamber 111 is lower than the oil inlet 132 and higher than the preset oil level, since the substance entering the oil storage chamber 111 at this time is an oil-gas mixture or a pure gaseous refrigerant, and the oil inlet amount is less than the oil outlet amount, based on the Venturi principle, the lubricating oil in the oil storage chamber 111 flows back to the air intake pipe through the first oil return hole 1231 and the second oil return hole 1232 at the same time, and flows out of the oil storage chamber 111 through the oil inlet 132 driven by the gaseous refrigerant in the air intake pipe. In this way, the amount of oil flowing back to the air intake pipe can be accelerated, the oil level drop speed of the oil storage chamber 111 can be accelerated, and the response time of the monitoring device can be shortened, so that the invalid oil return of the oil separator 300 can be found more quickly.

[0081] Preferably, the first oil return hole 1231 is disposed close to the bottom wall of the oil storage chamber 111 , so that as much lubricating oil as possible can be discharged, thereby increasing the oil return amount of the compressor 200 .

[0082] Preferably, the second oil return hole 1232 is arranged above the preset oil level, so as to increase the response speed of the monitoring device.

[0083] Furthermore, the aperture of the first oil return hole 1231 is smaller than that of the second oil return hole 1232. In actual operation, when the oil level of the oil storage chamber 111 is lower than that of the second oil return hole 1232, the lubricating oil can only flow back to the oil inlet pipe 120 through the first oil return hole 1231, and then return to the compressor 200 along with the gas. The aperture of the first oil return hole 1231 is smaller than that of the second oil return hole 1232. The large aperture of the second oil return hole 1232 is mainly used to speed up the response speed, while the small aperture of the first oil return hole 1231 is to reduce the influence of the falling oil level corresponding to the amount of oil flowing out through the first oil return hole 1231 on the oil level of the oil storage chamber 111 when the oil-gas mixture enters the oil storage chamber 111. The setting of the first oil return hole 1231 should make the oil inflow amount equal to the oil outflow amount when the oil-gas mixture with the target oil content enters the oil storage chamber 111. When the oil-gas mixture with oil content higher than the target oil content enters the oil storage chamber 111, the oil level in the oil storage chamber 111 does not drop, and the oil separator 300 effectively returns the oil. When the oil-gas mixture with oil content lower than the target oil content enters the oil storage chamber 111, the oil level in the oil storage chamber 111 drops, and the oil separator 300 does not effectively return the oil.

[0084] The target oil content refers to the content of lubricating oil in the oil-gas mixture that can meet the oil return volume of the compressor 200 after testing.

[0085] In some embodiments, see Figure 2 , Figure 4 and Figure 5 The monitoring component 140 includes a sensing member 142 and a floating member 141. The floating member 141 is disposed in the oil storage chamber 111 and can float in the direction of gravity along with the oil in the oil storage chamber 111. The sensing member 142 is disposed in the housing 110 and can sense the floating member 141 within a set range. The sensing member 142 generates an electrical signal as a first oil level characteristic when sensing the floating member 141, and generates an electrical signal as a second oil level characteristic when not sensing the floating member 141. The control member is electrically connected to the sensing member 142, and is used to determine whether the oil separator 300 effectively returns oil according to the first oil level characteristic, and is used to determine whether the oil separator 300 does not effectively return oil according to the second oil level characteristic.

[0086] In actual operation, when the oil level in the oil storage chamber 111 changes, the height of the floating member 141 in the direction of gravity changes. When the floating member 141 rises to within the set range that the sensing member 142 can sense, the sensing member 142 generates an electrical signal as a first oil level characteristic, and the control member determines that the oil separator 300 effectively returns oil based on the first oil level characteristic. When the floating member 141 drops to outside the set range that the sensing member 142 can sense, the sensing member 142 cannot sense the floating member 141 and generates an electrical signal as a second oil level characteristic, and the control member determines that the oil separator 300 does not effectively return oil based on the second oil level characteristic.

[0087] See also Figure 4 and Figure 5 , Figure 4 This is a state diagram when the floating member 141 is located within the set range, that is, the lubricating oil in the oil storage chamber 111 is sufficient, and at this time, the oil separator 300 effectively returns oil. Figure 5 This is a state diagram when the floating member 141 is outside the set range, that is, the lubricating oil in the oil storage chamber 111 is insufficient, and the oil separator 300 does not effectively return oil at this time.

[0088] In other embodiments, a liquid level sensor may be provided to detect the oil level height, and the detected oil level height may be used as an oil level feature. When the oil level height is greater than or equal to a preset oil level height, effective oil return is determined, otherwise, ineffective oil return is determined.

[0089] Specifically in the embodiment, the sensing element 142 is a proximity switch, and a metal sheet 1412 is provided on the floating element 141. When the proximity switch senses the metal sheet 1412, it generates an electrical signal as a first oil level characteristic, and when the metal sheet 1412 is not sensed, it generates an electrical signal as a second oil level characteristic.

[0090] Preferably, see Fig. 9 and Fig.10 The floating member 141 includes a floating ring 1411 and a metal sheet 1412 disposed on the floating ring 1411. The floating ring 1411 is used to be sleeved on the tube body of the oil inlet pipe 120 located in the oil storage chamber 111. At this time, the oil inlet pipe 120 can guide the floating of the floating member 141 to prevent the floating member 141 from tilting, thereby improving the sensing accuracy of the sensing member 142.

[0091] Specifically in the embodiment, the side wall of the oil storage chamber 111 is provided with a limit portion 112, and the floating member 141 floats between the limit portion 112 and the bottom wall of the oil storage chamber 111. The limit portion 112 is arranged corresponding to the set range to prevent the floating member 141 from floating to a position exceeding the set range. At this time, the limit portion 112 is used to limit the floating range of the floating member 141. The limit portion 112 is arranged corresponding to the set range. Even if the oil level in the oil storage chamber 111 exceeds the set range, the floating member 141 will be within the set range. At this time, the sensor 142 can always sense the floating member 141 to continuously output the first oil level feature. In this way, the high cost problem caused by the need to increase the number of sensors 142 when the floating member 141 continues to rise with the oil level is avoided.

[0092] Furthermore, the limiting portion 112 is lower than the oil inlet 132. At this time, the floating member 141 can be prevented from blocking the oil inlet 132.

[0093] Furthermore, the limiting portion 112 is a limiting ring protruding on the inner wall of the oil storage cavity 111 along the circumference of the oil storage cavity 111. At this time, the limiting portion 112 is used to simultaneously limit the floating member 141 in all directions, which helps to ensure the sensing accuracy of the sensing member 142.

[0094] Specifically, the housing 110 has a groove which is arranged along the circumference of the housing 110 and is recessed toward the oil storage cavity 111 . The groove is located on the inner wall of the oil storage cavity 111 and serves as the above-mentioned limiting ring.

[0095] The oil return monitoring device 100 can determine whether the oil separator 300 effectively returns by determining the oil level characteristics in the oil storage chamber 111, thereby avoiding the risk of damage to the compressor 200 due to lack of oil when the oil separator 300 cannot effectively return.

[0096] Based on the same inventive concept, please refer to Fig.11 In one embodiment of the present application, an air conditioning system is further provided, comprising a compressor 200, an oil return solenoid valve 400, an oil return separator 300, and the oil return monitoring device 100 in any of the above embodiments, wherein the oil inlet side of the oil return separator 300 is connected to the exhaust side of the compressor 200, the oil return solenoid valve 400 is connected to the oil outlet side of the oil return separator 300 and the oil inlet 122 of the oil return monitoring device 100, and the oil outlet 131 of the oil return monitoring device 100 is connected to the suction side of the compressor 200. Since the air conditioning system comprises the above oil return monitoring device 100, it has all the above beneficial effects, which will not be described in detail here.

[0097] In addition, the air-conditioning system also includes an outdoor heat exchanger 600, an electromagnetic expansion valve 900, an indoor heat exchanger 700, a gas-liquid separator 800, etc., which form a refrigerant circuit with the compressor 200, and may also include an oil return capillary 500 connected between the oil return solenoid valve 400 and the oil return monitoring device 100. The connection relationship between the various components can refer to the existing technology and will not be repeated here.

[0098] Based on the same inventive concept, please refer to Fig.12 In one embodiment of the present application, there is also provided an oil return control method for an air conditioning system, comprising:

[0099] S1, obtaining the oil level characteristics in the oil storage cavity 111;

[0100] S2. When the oil level characteristic indicates that the oil level in the oil storage chamber 111 is higher than or equal to the preset oil level, it is determined that the oil separator 300 effectively returns oil;

[0101] S3. When the oil level characteristic indicates that the oil level in the oil storage chamber 111 is lower than the preset oil level, it is determined that the oil separator 300 does not effectively return oil.

[0102] The oil return control method in this embodiment is applied to an air conditioning system, which includes a compressor 200, an oil return solenoid valve 400, an oil return separator 300, and an oil return monitoring device 100 in any of the above embodiments, wherein the oil inlet side of the oil return separator 300 is connected to the exhaust side of the compressor 200, the oil return solenoid valve 400 is connected to the oil outlet side of the oil return separator 300 and the oil inlet 122 of the oil return monitoring device 100, and the oil outlet 131 of the oil return monitoring device 100 is connected to the suction side of the compressor 200. When the air conditioning system is running, the oil return solenoid valve 400 is opened, and the oil separator 300 begins to separate the refrigerant and the lubricating oil. The lubricating oil in the oil separator 300 enters the oil return detection device through the oil return solenoid valve 400, and the oil return monitoring device 100 detects the oil level characteristics in the oil storage chamber 111.

[0103] The oil level characteristic can be used to determine whether the oil separator 300 effectively returns oil. When the oil level characteristic indicates that the oil level is not lower than the preset oil level, it is determined that the oil separator 300 effectively returns oil. When the oil level characteristic indicates that the oil level is lower than the preset oil level, it is determined that the oil separator 300 does not effectively return oil.

[0104] The above oil return control method can determine whether the oil separator 300 effectively returns by judging the oil level characteristics in the oil storage chamber 111, thereby avoiding the risk of damage to the compressor 200 due to lack of oil when the oil separator 300 cannot effectively return.

[0105] Specifically in the embodiment, step S4 is included after step S2, and step S5 is included after step S3, which are specifically as follows:

[0106] S4, keep the oil return solenoid valve 400 open;

[0107] S5. Control the oil return of the air-conditioning system. When the oil return of the air-conditioning system is in progress, the oil return solenoid valve 400 is closed, the compressor 200 in the air-conditioning system operates at a preset maximum frequency, and all valves in the air-conditioning system except the oil return solenoid valve 400 are adjusted to a preset maximum opening.

[0108] In this embodiment, when the oil return monitoring device 100 determines that the oil separator 300 effectively returns oil, the oil return solenoid valve 400 is kept open, so that the discharge of the oil separator 300 smoothly enters the oil return monitoring device 100, and the lubricating oil flows back to the compressor 200. When it is determined that the oil separator 300 does not effectively return oil, the air conditioning system will return oil. When the air conditioning system returns oil, the oil return solenoid valve 400 is closed, the compressor 200 runs at a preset maximum frequency, and the valve opening of the air conditioning system except the oil return solenoid valve 400 is adjusted to the maximum to flush the accumulated oil in the air conditioning system pipeline into the oil separator 300 and the compressor 200 oil pool. At this time, the oil separator 300 stores a sufficient amount of lubricating oil. It should be noted that when the system returns, the temperature difference between the indoor heat exchanger 700 and the outdoor heat exchanger 600 of the air conditioning system will be neutralized, resulting in the air conditioning system being unable to effectively cool or heat, wasting energy consumption, so the number of system oil returns should be reduced.

[0109] Specifically in the embodiment, the step of obtaining the oil level characteristics in the oil storage cavity 111 specifically includes:

[0110] S11, when the oil return solenoid valve 400 is in the open state, determining whether the air conditioning system returns oil;

[0111] S12: If yes, wait for a set time and obtain the oil level characteristics in the oil storage cavity 111;

[0112] S13: If not, obtain the oil level characteristics in the oil storage cavity 111.

[0113] In this embodiment, whether the oil separator 300 effectively returns oil is determined based on the oil level characteristics, specifically, whether the oil level in the oil storage chamber 111 is lower than a preset oil level, and the preset oil level is greater than zero. In order to avoid the situation where the oil separator 300 has sufficient lubricating oil, when the oil level in the oil storage chamber 111 is lower than the preset oil level in the early stage of the lubricating oil flowing into the oil storage chamber 111, it is misjudged that the oil return separator 300 does not effectively return oil, that is, it is misjudged that the compressor 200 is short of oil, causing the system to return oil again. It is required that when the oil return monitoring device 100 starts to monitor the oil level changes in the storage chamber, the storage chamber needs to have a preset oil level of oil buffered in it.

[0114] In order to store the oil volume of the preset oil level in the storage chamber, in this embodiment, when the oil return solenoid valve 400 is opened, it is determined whether the system returns oil. If so, it is necessary to avoid the oil return solenoid valve 400 being opened for the first time after the oil return, and it is necessary to wait for a preset time before starting to obtain the oil level characteristics of the oil storage chamber 111, so that the oil volume of the preset oil level is cached in the oil storage chamber 111. If the oil return solenoid valve 400 is not opened for the first time after the oil return, the oil level characteristics of the oil storage chamber 111 are directly obtained.

[0115] This embodiment can avoid the situation in which the oil return separator 300 is misjudged as not effectively returning oil to the compressor 200 due to the oil level being lower than the preset oil level during the oil buffering process, causing the system to return oil again. In this way, the monitoring results are accurate, multiple oil returns in the system are avoided, and the system energy efficiency can be improved.

[0116] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0117] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. An oil return monitoring device, characterized in that: include: The housing (110) has an oil storage chamber (111) for buffering oil; An oil inlet pipe (120) is provided on the housing (110) and has an oil inlet (122) and an oil inlet outlet (121) that are connected to each other, wherein the oil inlet (122) is used to be connected to the oil outlet side of the oil separator (300), and the oil inlet outlet (121) is connected to the oil storage chamber (111); an oil outlet pipe (130) disposed on the housing (110) and having an oil inlet (132) and an oil outlet (131) that are connected to each other, the oil inlet (132) being connected to the oil storage chamber (111), and the oil outlet (131) being used to be connected to the suction side of the compressor (200); and A monitoring component (140) is disposed on the housing (110) and is used to obtain oil level characteristics of the oil storage chamber (111) and determine whether the oil separator (300) effectively returns oil based on the oil level characteristics; The monitoring component (140) includes a sensing element (142), a floating element (141) and a control element; The floating member (141) is disposed in the oil storage chamber (111) and can float in the direction of gravity along with the oil in the oil storage chamber (111); the sensing member (142) is disposed in the housing (110) and can sense the floating member (141) within a set range, and the sensing member (142) generates an electrical signal as a first oil level characteristic when sensing the floating member (141), and generates an electrical signal as a second oil level characteristic when not sensing the floating member (141); The control component is communicatively connected to the sensing component (142) and is used to determine whether the oil separator (300) effectively returns oil based on the first oil level characteristic, and is used to determine whether the oil separator (300) does not effectively return oil based on the second oil level characteristic.

2. The oil return monitoring device according to claim 1, characterized in that: In the direction of gravity, the oil inlet (132) is arranged higher than the bottom wall of the oil storage chamber (111).

3. The oil return monitoring device according to claim 2, characterized in that: One end of the oil inlet pipe (120) having the oil inlet outlet (121) passes through the bottom wall of the oil storage chamber (111) and extends toward the inner wall portion of the oil storage chamber (111) that is higher than the oil inlet and outlet (132).

4. The oil return monitoring device according to claim 3, characterized in that: An oil return hole (123) is provided on the oil inlet pipe (120) located in the oil storage chamber (111), and the oil return hole (123) communicates the oil inlet pipe (120) and the oil storage chamber (111); In the gravity direction, the oil return hole (123) is arranged closer to the bottom wall of the oil storage chamber (111) than the oil inlet (132).

5. The oil return monitoring device according to claim 4, characterized in that: The oil return hole (123) comprises a first oil return hole (1231) and a second oil return hole (1232); the first oil return hole (1231) is arranged closer to the bottom wall of the oil storage chamber (111) than the second oil return hole (1232).

6. The oil return monitoring device according to claim 5, characterized in that: The aperture of the first oil return hole (1231) is smaller than the aperture of the second oil return hole (1232).

7. The oil return monitoring device according to claim 1, characterized in that: The side wall of the oil storage chamber (111) is provided with a limiting portion (112), and the floating member (141) floats between the limiting portion (112) and the bottom wall of the oil storage chamber (111); the limiting portion (112) is arranged corresponding to the set range, so as to prevent the floating member (141) from floating to a position exceeding the set range.

8. The oil return monitoring device according to claim 7, characterized in that: The limiting portion (112) is lower than the oil inlet (132).

9. An air conditioning system, characterized in that: The invention comprises a compressor (200), an oil return solenoid valve (400), an oil return separator (300), and an oil return monitoring device (100) according to any one of claims 1 to 8, wherein the oil inlet side of the oil return separator (300) is connected to the exhaust side of the compressor (200), the oil return solenoid valve (400) is connected to the oil outlet side of the oil return separator (300) and the oil inlet (122) of the oil return monitoring device (100), and the oil outlet (131) of the oil return monitoring device (100) is connected to the suction side of the compressor (200).

10. An oil return control method, applied to the oil return monitoring device according to any one of claims 1 to 8 or the air conditioning system according to claim 9, characterized in that: include: Acquiring oil level characteristics in the oil storage chamber (111); When the oil level characteristic indicates that the oil level in the oil storage chamber (111) is higher than or equal to the preset oil level, it is determined that the oil separator (300) effectively returns oil; When the oil level characteristic indicates that the oil level in the oil storage chamber (111) is lower than the preset oil level, it is determined that the oil separator (300) has not effectively returned oil.

11. The oil return control method according to claim 10, characterized in that: After the step of determining whether the oil separator (300) effectively returns oil, the method further comprises: Maintain the oil return solenoid valve (400) open; After the step of determining that the oil separator (300) does not effectively return oil, the method further comprises: The oil return of the air conditioning system is controlled. When the oil return of the air conditioning system is performed, the oil return solenoid valve (400) is closed, the compressor (200) in the air conditioning system is operated at a preset maximum frequency, and all valves in the air conditioning system except the oil return solenoid valve (400) are adjusted to a preset maximum opening.

12. The oil return control method according to claim 11, characterized in that: The step of obtaining the oil level characteristics in the oil storage cavity (111) specifically comprises: When the oil return solenoid valve (400) is in an open state, determining whether the air conditioning system returns oil; If yes, wait for a set time and then obtain the oil level characteristics in the oil storage chamber (111); If not, the oil level characteristics in the oil storage cavity (111) are obtained.

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