Air conditioning systems and their control methods, control devices, and air conditioning equipment

Abstract

This application relates to an air conditioning system and its control method, control device, and air conditioning equipment. The air conditioning system includes a compressor, a detection device, a control device, and a capillary network and an electronic expansion valve connected in series between the output and input ends of the compressor. The control method of the air conditioning system includes: when the air conditioning system enters oil return mode, controlling the electronic expansion valve connected in series with the capillary network to close, so that the refrigerant accumulates and condenses into a liquid state in the capillary network; acquiring the operating parameters of the air conditioning system; and, when it is determined that the operating parameters meet a first preset condition, controlling the electronic expansion valve to open so that the lubricating oil and refrigerant in the capillary network return to the compressor. The first preset condition is used to indicate that the liquid refrigerant has accumulated to a preset value in the capillary network. The solution of this application enables the lubricating oil in the capillary network to return to the compressor, solving the problems of high oil film thermal resistance in the capillary network and compressor wear due to oil retention in the capillary network.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and in particular to an air conditioning system and its control method, control device, and air conditioning equipment. Background Technology

[0002] Air conditioning systems provide underfloor heating by supplying high-temperature refrigerant, such as Freon, to a capillary network for heating. During operation, the compressor in an air conditioning system requires lubricating oil, and inevitably, a small amount of lubricating oil enters the refrigerant circulation lines with the compressor exhaust. This lubricating oil accumulates over time. Because the capillary network for heating has a small diameter and long length, once the lubricating oil enters the heating lines, it is difficult to return it to the compressor oil sump using existing air conditioning oil return technology. This results in high thermal resistance of the oil film within the capillary network and potential compressor damage due to insufficient oil supply. Summary of the Invention

[0003] This application provides an air conditioning system and its control method, control device, and air conditioning equipment to solve the problems of high thermal resistance of the oil film in the capillary network and wear of the compressor due to oil retention in the capillary network.

[0004] In a first aspect, this application provides an air conditioning system, comprising a compressor, a detection device, a control device, and a capillary network and an electronic expansion valve connected in series between the output and input ends of the compressor; the refrigerant compressed by the compressor can enter the capillary network to release heat and then return to the compressor through the electronic expansion valve; the detection device is used to detect the operating parameters of the air conditioning system; the control device is used to: control the electronic expansion valve to close in oil return mode, so that the refrigerant accumulates and condenses into a liquid state in the capillary network; and control the electronic expansion valve to open when the operating parameters meet a first preset condition, so that the lubricating oil in the capillary network and the refrigerant return to the compressor, wherein the lubricating oil remaining in the capillary network is miscible with the liquid refrigerant, and the first preset condition is used to indicate that the liquid refrigerant accumulates in the capillary network to a preset value.

[0005] In one possible implementation, the detection device includes a first temperature detection device disposed at the inlet of the capillary network and used to detect the temperature at which the refrigerant enters the capillary network; wherein: the operating parameters include the detection temperature of the first temperature detection device, and the first preset condition includes that the detection temperature of the first temperature detection device is less than or equal to a first preset temperature threshold; or, the detection device further includes a second temperature detection device disposed at the outlet of the capillary network and used to detect the temperature at which the refrigerant flows out of the capillary network, or disposed in the room where the capillary network is located and used to detect the indoor ambient temperature, wherein the operating parameters include the detection temperatures of the first temperature detection device and the second temperature detection device, and the first preset condition includes that the difference between the detection temperatures of the first temperature detection device and the second temperature detection device is less than or equal to a second preset temperature threshold.

[0006] In other words, in this implementation, the temperature at which the refrigerant enters the capillary network (inlet temperature) can be detected, and the inlet temperature can be compared with a first preset temperature threshold to determine whether the capillary network is full of refrigerant; the temperature at which the refrigerant flows out of the capillary network (outlet temperature) or the temperature of the room where the capillary network is located (indoor ambient temperature) can also be detected, and the difference between the inlet temperature and the outlet temperature or the indoor ambient temperature can be compared with a second preset temperature threshold to determine whether the capillary network is full of refrigerant.

[0007] In one possible implementation, the control device is further configured to control the operating frequency of the compressor to be greater than or equal to a preset frequency threshold when the operating parameters meet the first preset condition and the electronic expansion valve is controlled to open.

[0008] In other words, in this implementation, in order to smoothly discharge the liquid refrigerant and lubricating oil from the capillary network, the operating frequency of the compressor can be increased when the operating frequency of the compressor is low; and the operating frequency of the compressor can be kept constant when the operating frequency of the compressor is high.

[0009] In one possible implementation, the air conditioning system further includes a first timing device for recording the operating time of the air conditioning system in normal operating mode; the control device is used to control the air conditioning system to enter the oil return mode when it is determined that the operating time of the air conditioning system in normal operating mode has reached a first preset duration.

[0010] In other words, in this implementation, if the working time of the air conditioning system is longer than the first preset time, it can be determined that a large amount of lubricating oil has accumulated in the capillary network and the heat exchange efficiency of the capillary network is low. At this time, the air conditioning system can be controlled to enter the oil return mode in order to discharge the lubricating oil in the capillary network and thereby improve the heat exchange efficiency of the capillary network.

[0011] In one possible implementation, the control device is further configured to control the air conditioning system to exit the oil return mode when it is determined that the operating parameters meet a second preset condition, wherein the second preset condition is used to indicate that the liquid refrigerant and lubricating oil in the capillary network have flowed out.

[0012] In other words, in this implementation, once it is determined that the liquid refrigerant and lubricating oil in the capillary network have flowed out, the air conditioning system can return to normal operating mode. For example, in oil return mode, the operating frequency of the compressor is increased, while in normal operating mode, the operating frequency of the compressor can be reduced.

[0013] In one possible implementation, the operating parameters include the detected temperature of the first temperature detection device of the detection device, and the second preset condition includes the detected temperature of the first temperature detection device being greater than or equal to a third preset temperature threshold; or, the detection device includes a second timing device, the second timing device being used to record the running time of the air conditioning system in the oil return mode, the operating parameters including the running time of the air conditioning system in the oil return mode, and the second preset condition including the running time in the oil return mode being greater than or equal to a second preset duration.

[0014] In other words, in this implementation, the liquid refrigerant and lubricating oil can be determined by comparing the detected temperature (i.e., the inlet pipe temperature) of the first temperature detection device with the third preset temperature threshold; or, the running time of the air conditioning system in the oil return mode can be compared with the second preset time to determine whether the liquid refrigerant and lubricating oil have flowed out of the capillary network.

[0015] Secondly, this application provides a control method for an air conditioning system, the control method comprising: when the air conditioning system enters an oil return mode, controlling an electronic expansion valve connected in series with a capillary network to close, so that refrigerant accumulates and condenses into a liquid state in the capillary network, wherein the lubricating oil remaining in the capillary network is miscible with the liquid refrigerant; acquiring the operating parameters of the air conditioning system, the operating parameters being obtained by detection by a detection device of the air conditioning system; and when it is determined that the operating parameters meet a first preset condition, controlling the electronic expansion valve to open so that the lubricating oil and the refrigerant in the capillary network return to the compressor, the first preset condition being used to indicate that the liquid refrigerant accumulates in the capillary network to a preset value.

[0016] In other words, in this implementation, by controlling the electronic expansion valve connected in series with the capillary network to close, the capillary network can be filled with liquid refrigerant. Then, by controlling the electronic expansion valve connected in series with the capillary network to open, the lubricating oil and refrigerant can be pushed out of the capillary network and returned to the compressor by utilizing the miscibility between the liquid refrigerant condensed in the capillary network and the lubricating oil.

[0017] In one possible implementation, when performing the step of controlling the electronic expansion valve to open so that the lubricating oil and the refrigerant in the capillary network return to the compressor, the control method further includes: controlling the operating frequency of the compressor to be greater than or equal to a preset frequency threshold.

[0018] In other words, in this implementation, when the electronic expansion valve opens in oil return mode, the compressor can maintain a high operating frequency so that the liquid refrigerant and lubricating oil can be discharged from the capillary network as soon as possible.

[0019] In one possible implementation, the control method further includes: obtaining the running time of the air conditioning system in normal mode; and, when it is determined that the running time of the air conditioning system in normal mode has reached a first preset duration, controlling the air conditioning system to enter the oil return mode.

[0020] In other words, in this implementation, the need for the air conditioning system to enter the oil return mode can be determined by the operating time of the air conditioning system in normal mode.

[0021] In one possible implementation, the control method further includes: when it is determined that the operating parameters meet a second preset condition, controlling the air conditioning system to exit the oil return mode, wherein the second preset condition is used to indicate that the liquid refrigerant and the lubricating oil in the capillary network have flowed out.

[0022] In other words, in this implementation, once it is determined that the liquid refrigerant and lubricating oil in the capillary network have flowed out, the air conditioning system can exit the oil return mode in order to return to the normal working mode.

[0023] Thirdly, this application provides a control device for an air conditioning system, the control device comprising: a control module, configured to control an electronic expansion valve connected in series with a capillary network to close when the air conditioning system enters an oil return mode, so that refrigerant accumulates and condenses into a liquid state in the capillary network, wherein the lubricating oil remaining in the capillary network is miscible with the liquid refrigerant; an acquisition module, configured to acquire operating parameters of the air conditioning system, the operating parameters being obtained by a detection device of the air conditioning system; the control module is further configured to control the electronic expansion valve to open when it is determined that the operating parameters meet a first preset condition, so that the lubricating oil and refrigerant in the capillary network return to the compressor, the first preset condition being used to indicate that the liquid refrigerant accumulates in the capillary network to a preset value.

[0024] Fourthly, this application provides an air conditioning device, including a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the control method described in the second aspect above.

[0025] Fifthly, this application also provides a computer storage medium having computer-executable instructions stored thereon for performing the steps of the method described in the second aspect above.

[0026] Compared with the prior art, the above-mentioned technical solution provided in this application has the following advantages: The air conditioning system provided in this application can fill the capillary network with liquid refrigerant by controlling the electronic expansion valve connected in series with the capillary network to close. Then, the electronic expansion valve connected in series with the capillary network is opened. By utilizing the characteristic that the liquid refrigerant condensed in the capillary network is miscible with the lubricating oil, the lubricating oil and refrigerant are pushed out of the capillary network and returned to the compressor together. This solves the problem of high oil film thermal resistance in the capillary network and compressor wear due to oil storage in the capillary network, which helps to improve the heat exchange efficiency of the capillary network and extend the service life of the compressor. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0030] Figure 1 This application provides a schematic diagram of the structure of an air conditioning system according to an embodiment of the present application.

[0031] Figure 2 A flowchart illustrating a control method for an air conditioning system provided in an embodiment of this application;

[0032] Figure 3 A flowchart illustrating another control method for an air conditioning system provided in an embodiment of this application;

[0033] Figure 4 This is a schematic diagram of the structure of a control device for an air conditioning system provided in an embodiment of this application;

[0034] Figure 5 This is a schematic diagram of the structure of an air conditioning device provided in an embodiment of this application. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0037] To address the technical problems of high oil film thermal resistance and compressor wear due to oil retention in the capillary network in existing technologies, this application provides an air conditioning system and its control method, control device, and air conditioning equipment. This system enables the lubricating oil in the capillary network to return to the compressor, avoiding the problem of compressor wear due to oil retention in the capillary network, thus helping to extend the service life of the compressor. Furthermore, it reduces the thermal resistance of the oil film in the capillary network and improves the heat exchange efficiency of the capillary network.

[0038] Figure 1 This is a schematic diagram of an air conditioning system provided in an embodiment of this application. Figure 1 As shown, the air conditioning system includes a compressor 10 and a detection device ( Figure 1 (not shown in the image), control device ( Figure 1 (Not shown in the image) and a capillary network 20 connected in series between the output and input ends of the compressor 10, and an electronic expansion valve EXV1. The refrigerant compressed by the compressor 10 can enter the capillary network 20 to release heat and then return to the compressor 10 through the electronic expansion valve EXV1.

[0039] The detection device is used to detect the operating parameters of the air conditioning system; the control device is used, in oil return mode, to: control the electronic expansion valve EXV1 to close, so that the refrigerant accumulates and condenses into a liquid state in the capillary network 20; and to control the electronic expansion valve EXV1 to open when the operating parameters meet a first preset condition, so that the lubricating oil and refrigerant in the capillary network 20 return to the compressor 10, wherein the lubricating oil remaining in the capillary network 20 is miscible with the liquid refrigerant, and exemplarily, the refrigerant may be Freon. The first preset condition is used to indicate that the liquid refrigerant accumulates in the capillary network 20 to a preset value, exemplarily, the preset value may be that the liquid refrigerant is full in the capillary network 20.

[0040] The air conditioning system provided in this application embodiment, by controlling the electronic expansion valve EXV1 connected in series with the capillary network 20 to close, can fill the capillary network with liquid refrigerant. Then, by controlling the electronic expansion valve EXV1 connected in series with the capillary network 20 to open, the lubricating oil and refrigerant are pushed out of the capillary network 20 and returned to the compressor 10 together by the characteristic that the liquid refrigerant condensed in the capillary network 20 is miscible with the lubricating oil. This solves the problem of high thermal resistance of the oil film in the capillary network 20 caused by oil accumulation and oil shortage wear of the compressor 10, and helps to improve the heat exchange efficiency of the capillary network 20 and extend the service life of the compressor 10.

[0041] In some embodiments, the air conditioning system may also include other components. For example, such as... Figure 1 As shown, the input end of compressor 10 is connected to the output end of gas-liquid separator 40, and the output end of compressor 10 is connected to the input end of oil separator 50. The output end of oil separator 50 is connected to the input ends of first four-way valve T1 and second four-way valve T2. The output ends of both first four-way valve T1 and second four-way valve T2 are connected to the input end of gas-liquid separator 40. The other output end of second four-way valve T2 is also connected in sequence to outdoor heat exchanger 30 and electronic expansion valve EXV5. A low-pressure sensor S1 can also be installed on the pipeline at the input end of gas-liquid separator 40, and a high-pressure sensor S2 can also be installed on the pipeline at the output end of oil separator 50.

[0042] One end of the first indoor unit N1 (two-pipe indoor unit) and the electronic expansion valve EXV2, connected in series, is sequentially connected to the first valve F1, the electronic expansion valve EXV3, and the outdoor heat exchanger 30 via the first pipeline L1. The other end of the first indoor unit N1 (two-pipe indoor unit) and the electronic expansion valve EXV2, connected in series, is sequentially connected to the second valve F2 and the other output end of the first four-way valve T1 via the second pipeline L2.

[0043] One end of the first heat exchanger of the second indoor unit N2 (three-tube indoor unit) is connected in series with the electronic expansion valve EXV3 and then connected to the first valve F1. The other end of the first heat exchanger of the second indoor unit N2 (three-tube indoor unit) is connected in sequence to the input ends of the third valve F3, the first four-way valve T1 and the second four-way valve T2 through the third pipeline L3. One end of the second heat exchanger of the second indoor unit N2 (three-tube indoor unit) is connected in series with the electronic expansion valve EXV4 and then connected to the first valve F1. The other end of the second heat exchanger of the second indoor unit N2 (three-tube indoor unit) is connected in sequence to the second valve F2 and the other output end of the first four-way valve T1 through the second pipeline L2.

[0044] For example, the air conditioning system may also include a first timing device ( Figure 1 (Not shown in the image), the first timing device is used to record the running time of the air conditioning system in normal operating mode; the control device can be used to control the air conditioning system to enter the oil return mode when it is determined that the running time of the air conditioning system in normal operating mode has reached a first preset time.

[0045] Furthermore, in some implementations, the detection device includes a first temperature detection device, which is located at the inlet of the capillary network 20 and used to detect the temperature at which the refrigerant enters the capillary network 20. Operating parameters include the detection temperature of the first temperature detection device, and a first preset condition includes the detection temperature of the first temperature detection device being less than or equal to a first preset temperature threshold.

[0046] In some other implementations, the detection device includes not only a first temperature detection device but also a second temperature detection device. The second temperature detection device is located at the outlet of the capillary network 20 and is used to detect the temperature of the refrigerant flowing out of the capillary network 20, or it is located in the room where the capillary network 20 is located and is used to detect the indoor ambient temperature. The operating parameters include the detection temperature of the first temperature detection device and the detection temperature of the second temperature detection device. The first preset condition includes that the difference between the detection temperature of the first temperature detection device and the detection temperature of the second temperature detection device is less than or equal to a second preset temperature threshold.

[0047] Furthermore, in order to increase the refrigerant flow rate and velocity within the capillary network 20, the control device is also used to control the operating frequency of the compressor 10 to be greater than or equal to a preset frequency threshold when the operating parameters meet the first preset condition and the electronic expansion valve EXV1 is opened. This allows the mixture of liquid refrigerant and lubricating oil in the capillary network 20 to be discharged from the capillary network 20 as quickly as possible.

[0048] In addition, the control device is also used to control the air conditioning system to exit the oil return mode when the operating parameters meet the second preset condition. The second preset condition is used to indicate that the liquid refrigerant and lubricating oil in the capillary network 20 have flowed out.

[0049] In some embodiments, the operating parameters include the detection temperature of a first temperature detection device and a second preset condition including that the detection temperature of the first temperature detection device is greater than or equal to a third preset temperature threshold. In other embodiments, the detection device includes a second timing device for recording the operating time of the air conditioning system in oil return mode, and the operating parameters include the operating time of the air conditioning system in oil return mode and the second preset condition including that the operating time in oil return mode is greater than or equal to a second preset duration.

[0050] In other words, the oil return control method of the above-mentioned air conditioning system includes the following steps: First, when the air conditioning system has been running in normal mode for a first preset duration, the air conditioning system can be controlled to enter the oil return mode; when the air conditioning system enters the oil return mode, the electronic expansion valve EXV1 connected in series with the capillary network 20 is closed to allow the refrigerant to accumulate and condense into liquid in the capillary network 20; then, the operating parameters of the air conditioning system are detected by a detection device; next, when the operating parameters meet the first preset condition, the electronic expansion valve EXV1 is opened to allow the lubricating oil and refrigerant in the capillary network 20 to return to the compressor 10. The first preset condition is used to indicate that the liquid refrigerant has accumulated to a preset value in the capillary network 20, for example, the capillary network 20 is full of liquid refrigerant, so that the lubricating oil remaining in the capillary network 20 is as miscible as possible with the liquid refrigerant. Furthermore, the operating frequency of the compressor 10 can be controlled to be greater than or equal to a preset frequency threshold so as to push the liquid refrigerant and lubricating oil out of the capillary network 20 as quickly as possible. Then, when the operating parameters meet the second preset condition, the air conditioning system is controlled to exit the oil return mode. The second preset condition is used to indicate that the liquid refrigerant and lubricating oil in the capillary network 20 have flowed out.

[0051] Figure 2 This is a flowchart illustrating a control method for an air conditioning system provided in an embodiment of this application. The air conditioning system can be... Figure 1 The air conditioning system shown. (As shown) Figure 2 As shown, the control method for this air conditioning system may include the following steps:

[0052] S201, when the air conditioning system enters the oil return mode, controls the electronic expansion valve connected in series with the capillary network to close, so that the refrigerant accumulates and condenses into a liquid state in the capillary network, wherein the lubricating oil remaining in the capillary network can be miscible with the liquid refrigerant.

[0053] Since lubricating oil and liquid refrigerant are miscible, by controlling the electronic expansion valve to close for a period of time, liquid refrigerant can be gradually accumulated in the capillary network, thereby mixing the lubricating oil remaining in the capillary network with the liquid refrigerant, so that it can be discharged from the capillary network along with the refrigerant later.

[0054] S202, Obtain the operating parameters of the air conditioning system. The operating parameters are obtained by detecting the air conditioning system through the detection device.

[0055] For details regarding the detection device, please refer to the relevant description of the air conditioning system above. For example, the detection device may include a first temperature detection device, and may also include a second temperature detection device.

[0056] S203, when the operating parameters meet the first preset condition, the electronic expansion valve is opened to allow the lubricating oil and refrigerant in the capillary network to return to the compressor. The first preset condition is used to indicate that the liquid refrigerant accumulates to a preset value in the capillary network.

[0057] The specific details of the first preset condition can be found in the relevant description of the air conditioning system above. For example, the first preset condition may be that the temperature detected by the first temperature detection device is less than or equal to a first preset temperature threshold; or, the first preset condition may be that the difference between the temperature detected by the first temperature detection device and the temperature detected by the second temperature detection device is less than or equal to a second preset temperature threshold.

[0058] Furthermore, in some embodiments, when performing the step of controlling the electronic expansion valve to open so that the lubricating oil and refrigerant in the capillary network return to the compressor, in order to smoothly discharge the liquid refrigerant and lubricating oil in the capillary network, the operating frequency of the compressor can also be controlled to be greater than or equal to a preset frequency threshold.

[0059] For example, before S201, the running time of the air conditioning system in normal mode can be obtained first; then, the running time in normal mode is compared with a first preset time; then, if it is determined that the running time of the air conditioning system in normal mode has reached the first preset time (at this time, a lot of lubricating oil has accumulated in the capillary network), the air conditioning system can be controlled to enter the oil return mode.

[0060] Furthermore, if the operating parameters meet the second preset condition, the air conditioning system can be controlled to exit the oil return mode. The second preset condition is used to indicate that the liquid refrigerant and lubricating oil in the capillary network have flowed out.

[0061] The second preset condition can be found in the relevant description of the air conditioning system above. For example, the second preset condition could be that the temperature detected by the first temperature detection device is greater than or equal to the third preset temperature threshold.

[0062] In addition, Figure 1 In the illustrated air conditioning system, only one set of electronic expansion valves and capillary networks is shown as an example. In other embodiments, the air conditioning system may include multiple sets of electronic expansion valves and capillary networks connected in series. In this case, the control method may include: controlling multiple sets of electronic expansion valves and capillary networks connected in series to enter the oil return mode; or, controlling multiple sets of electronic expansion valves and capillary networks connected in series to enter the oil return mode at different times.

[0063] Figure 3 This is a flowchart illustrating another control method for an air conditioning system provided in an embodiment of this application. Figure 3 As shown, during the operation of underfloor heating, the oil return process in the heating capillary network is as follows:

[0064] First, determine the relationship between the operating time of the heating capillary network and the preset value t1 (the preset value t1 can be the first preset duration mentioned above). t1 can be obtained through experimental testing based on the relationship between the oil content in the heating capillary network and time. If the determination result is negative, the process ends; if the determination result is positive, that is, the operating time of the heating capillary network is ≥ t1, for example, when the operating time of the heating capillary network reaches the preset value t1, then close the heating capillary electronic expansion valve EXV1 and record the inlet temperature k1 (i.e., the temperature detected by the first temperature detection device mentioned above) and the outlet temperature k2 (i.e., the temperature detected by the second temperature detection device mentioned above) of the heating capillary network at this time.

[0065] Next, when EXV1 is closed, the heating capillary network continues to transfer heat to the floor. The high-temperature gaseous refrigerant inside the pipes is slowly condensed, and the refrigerant's state slowly changes from gaseous to liquid. Over time, this continues until the heating capillary network is full of liquid refrigerant. When the network is full, the inlet temperature k1 will decrease and approach the outlet temperature k2. If k1 - k2 ≤ preset value a (preset value a can be the second preset temperature threshold mentioned above), for example, a value of 2℃, then it is determined that the heating capillary network is full of liquid refrigerant.

[0066] In some embodiments, k2 in the judgment condition “k1-k2≤preset value a” can be replaced with the indoor ambient temperature; or, the judgment condition “k1-k2≤preset value a” can be replaced with “k1≤preset value c (preset value c can be the first preset temperature threshold mentioned above)”.

[0067] Then, fully open the electronic expansion valve EXV1 of the heating capillary network and adjust the compressor frequency to the preset value x. At this time, high-temperature and high-pressure refrigerant enters from the gas pipe of the heating capillary network, pushing out the liquid refrigerant inside the pipe. At the same time, lubricating oil will also be pushed out of the pipe until the inlet temperature of the heating capillary network k3 ≥ k1 + preset value b ("k1 + preset value b" can be the third preset temperature threshold mentioned above). For example, b can be 10℃, then it is determined that all the liquid refrigerant in the heating capillary network has been pushed out. Then, exit the oil return control, and the oil return operation mode of the heating capillary network ends.

[0068] In some embodiments, the judgment condition "heating capillary network inlet pipe temperature k3 ≥ k1 + preset value b" can be replaced with "running time in oil return mode ≥ preset time (the preset time can be the second preset time mentioned above)" or "k3 ≥ preset value d (the preset value d can be the third preset temperature threshold mentioned above)". Furthermore, multiple sets of heating capillary networks can be set up, and multiple sets of heating capillary networks can be controlled to return oil simultaneously or controlled to return oil one set at a time.

[0069] When lubricating oil adheres to the copper tubes of the capillary network, it prevents the refrigerant from contacting the copper tubes. The path of heat transfer from the refrigerant to the copper tubes is separated by lubricating oil; the thicker the lubricating oil film, the lower the heat transfer efficiency. The control method of this application embodiment enables the lubricating oil in the heating capillary network to flow back from the heating capillary network to the compressor oil sump. This solves the problem of high thermal resistance of the oil film in the capillary network due to the difficulty in draining lubricating oil, improves the heat exchange efficiency of the heating capillary network, and avoids the problem of compressor wear due to oil retention in the heating capillary network, thus helping to extend the compressor's service life.

[0070] Specifically, during the capillary network oil return process, EXV1 is closed until all the refrigerant in the pipes becomes liquid. When all the refrigerant in the pipes has become liquid, EXV1 is fully open, and the compressor operates at a fixed frequency. This controls the refrigerant flow rate in the heating capillary network to ensure it is filled with liquid refrigerant. When discharging the liquid refrigerant from the capillary network, the compressor operating frequency is increased to increase the refrigerant flow rate and velocity in the heating capillary. Utilizing the miscibility between the condensed liquid refrigerant and lubricating oil in the heating capillary network, the lubricating oil is pushed out of the heating capillary network and returned to the compressor.

[0071] Figure 4 This is a schematic diagram of the structure of a control device for an air conditioning system provided in an embodiment of this application. Figure 4As shown, the control device 400 includes an acquisition module 401 and a control module 402. The control module 402 is used to close the electronic expansion valve connected in series with the capillary network when the air conditioning system enters the oil return mode, so that the refrigerant accumulates and condenses into a liquid state within the capillary network, wherein the lubricating oil remaining in the capillary network is miscible with the liquid refrigerant. The acquisition module 401 is used to acquire the operating parameters of the air conditioning system, which are obtained by detection by the air conditioning system's detection device. The control module 402 is also used to open the electronic expansion valve when it is determined that the operating parameters meet a first preset condition, so that the lubricating oil and refrigerant in the capillary network return to the compressor. The first preset condition indicates that the liquid refrigerant has accumulated to a preset value within the capillary network.

[0072] In one possible implementation, when performing the step of controlling the electronic expansion valve to open so that the lubricating oil and refrigerant in the capillary network return to the compressor, the control module 402 is also used to control the operating frequency of the compressor to be greater than or equal to a preset frequency threshold.

[0073] In one possible implementation, the acquisition module 401 is used to acquire the running time of the air conditioning system in normal mode; the control module 402 is also used to control the air conditioning system to enter the oil return mode when it is determined that the running time of the air conditioning system in normal mode has reached a first preset time.

[0074] In one possible implementation, the control module 402 is also used to control the air conditioning system to exit the oil return mode when it is determined that the operating parameters meet the second preset condition, the second preset condition being used to indicate that the liquid refrigerant and lubricating oil in the capillary network have flowed out.

[0075] Figure 5 This is a structural schematic diagram of an air conditioning device provided in an embodiment of this application. Figure 5 As shown, the air conditioning unit 500 includes at least one processor 501, a memory 502, at least one network interface 504, and other user interfaces 503. The various components in the air conditioning unit 500 are coupled together via a bus system 505. It is understood that the bus system 505 is used to implement communication between these components. In addition to a data bus, the bus system 505 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in... Figure 5 The general designated all buses as Bus System 505.

[0076] The user interface 503 may include a display, keyboard, or clicking device (e.g., mouse, trackball, touchpad, or touchscreen).

[0077] It is understood that the memory 502 in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The memory 502 described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0078] In some implementations, memory 502 stores executable units or data structures, or subsets thereof, or extended sets thereof. For example, memory 502 includes an operating system 5021 and application programs 5022. The operating system 5021 contains various system programs, such as a framework layer, core library layer, and driver layer, for implementing various basic services and handling hardware-based tasks. Application programs 5022 contain various applications, such as a media player and a browser, for implementing various application services. Programs implementing the methods of the embodiments of this application may be included in application programs 5022.

[0079] In this embodiment, by calling the program or instructions stored in memory 502, specifically the program or instructions stored in application program 5022, processor 501 executes the method steps provided in each method embodiment. For example, these steps include: when the air conditioning system enters the oil return mode, controlling the electronic expansion valve connected in series with the capillary network to close, so that the refrigerant accumulates and condenses into a liquid state in the capillary network, wherein the lubricating oil remaining in the capillary network is miscible with the liquid refrigerant; acquiring the operating parameters of the air conditioning system, which are obtained by detecting the air conditioning system through a detection device; and when it is determined that the operating parameters meet a first preset condition, controlling the electronic expansion valve to open so that the lubricating oil and refrigerant in the capillary network return to the compressor, wherein the first preset condition is used to indicate that the liquid refrigerant accumulates to a preset value in the capillary network.

[0080] The methods disclosed in the embodiments of this application can be applied to or implemented by processor 501. Processor 501 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit of the hardware in processor 501 or by instructions in the form of software. The processor 501 may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software units in the decoding processor. The software units may be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory 502. Processor 501 reads the information in memory 502 and, in conjunction with its hardware, completes the steps of the above method.

[0081] It is understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described herein, or combinations thereof.

[0082] For software implementation, the techniques described herein can be implemented by units that perform the functions described herein. The software code can be stored in memory and executed by a processor. The memory can be implemented in the processor or external to the processor.

[0083] The air conditioning equipment provided in this embodiment can be as follows: Figure 5 The air conditioning equipment shown can perform the following functions: Figure 2 and Figure 3 All steps of the control method for the central air conditioning system, thereby achieving Figure 2 and Figure 3 For details on the technical effects of the control method for the air conditioning system shown, please refer to [link / reference]. Figure 2 and Figure 3 The relevant descriptions are presented concisely and will not be elaborated upon here.

[0084] This application also provides a storage medium (computer-readable storage medium). This storage medium stores one or more programs. The storage medium may include volatile memory, such as random access memory; it may also include non-volatile memory, such as read-only memory, flash memory, hard disk, or solid-state drive; or it may include combinations of the above types of memory. One or more programs in the storage medium can be executed by one or more processors to implement the control method of the air conditioning system described above.

[0085] The processor is used to execute a processing program for a list of devices stored in the memory to implement the steps of the following air conditioning system control method, for example including: when the air conditioning system enters the oil return mode, controlling the electronic expansion valve connected in series with the capillary network to close, so that the refrigerant accumulates and condenses into a liquid state in the capillary network, wherein the lubricating oil remaining in the capillary network is miscible with the liquid refrigerant; acquiring the operating parameters of the air conditioning system, the operating parameters being obtained by detection by the air conditioning system's detection device; and when it is determined that the operating parameters meet a first preset condition, controlling the electronic expansion valve to open so that the lubricating oil and refrigerant in the capillary network return to the compressor, the first preset condition being used to indicate that the liquid refrigerant accumulates to a preset value in the capillary network.

[0086] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0087] It should be noted that the terms "one implementation," "embodiment," "exemplary embodiment," and "some embodiments" used in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0088] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An air conditioning system, characterized in that, It includes a compressor, a detection device, a control device, and a capillary network and an electronic expansion valve connected in series between the output and input ends of the compressor; the refrigerant compressed by the compressor can enter the capillary network to release heat and then return to the compressor through the electronic expansion valve; The detection device is used to detect the operating parameters of the air conditioning system; the control device is used in oil return mode to: control the electronic expansion valve to close, so that the refrigerant accumulates and condenses into a liquid state in the capillary network; and control the electronic expansion valve to open when the operating parameters meet a first preset condition, so that the lubricating oil in the capillary network and the refrigerant return to the compressor, wherein the lubricating oil remaining in the capillary network is miscible with the liquid refrigerant, and the first preset condition is used to indicate that the liquid refrigerant accumulates in the capillary network to a preset value; The detection device includes a first temperature detection device, which is disposed at the inlet of the capillary network and used to detect the temperature at which the refrigerant enters the capillary network; wherein: the operating parameters include the detection temperature of the first temperature detection device, and the first preset condition includes the detection temperature of the first temperature detection device being less than or equal to a first preset temperature threshold; or, The detection device further includes a second temperature detection device, which is located at the outlet of the capillary network and used to detect the temperature of the refrigerant flowing out of the capillary network, or located in the room where the capillary network is located and used to detect the indoor ambient temperature. The operating parameters include the detection temperature of the first temperature detection device and the detection temperature of the second temperature detection device. The first preset condition includes that the difference between the detection temperature of the first temperature detection device and the detection temperature of the second temperature detection device is less than or equal to a second preset temperature threshold.

2. The air conditioning system according to claim 1, characterized in that, The control device is also used to control the operating frequency of the compressor to be greater than or equal to a preset frequency threshold when the operating parameters meet the first preset condition and the electronic expansion valve is opened.

3. The air conditioning system according to claim 1, characterized in that, The air conditioning system also includes a first timing device, which is used to record the running time of the air conditioning system in normal operating mode; The control device is used to control the air conditioning system to enter the oil return mode when it is determined that the running time of the air conditioning system in the normal working mode has reached a first preset time.

4. The air conditioning system according to any one of claims 1-3, characterized in that, The control device is also used to control the air conditioning system to exit the oil return mode when it is determined that the operating parameters meet the second preset condition, the second preset condition being used to indicate that the liquid refrigerant and lubricating oil in the capillary network have flowed out.

5. The air conditioning system according to claim 4, characterized in that: The operating parameters include the detection temperature of the first temperature detection device of the detection apparatus, and the second preset condition includes the detection temperature of the first temperature detection device being greater than or equal to a third preset temperature threshold; or... The detection device includes a second timing device for recording the running time of the air conditioning system in the oil return mode. The operating parameters include the running time of the air conditioning system in the oil return mode, and the second preset condition includes the running time in the oil return mode being greater than or equal to a second preset duration.

6. A control method for an air conditioning system, applied to the air conditioning system as described in any one of claims 1 to 5, characterized in that, include: When the air conditioning system enters the oil return mode, the electronic expansion valve connected in series with the capillary network is closed to allow the refrigerant to accumulate and condense into a liquid state in the capillary network, wherein the lubricating oil remaining in the capillary network is miscible with the liquid refrigerant. The operating parameters of the air conditioning system are obtained by detection through the detection device of the air conditioning system. When the operating parameters meet the first preset condition, the electronic expansion valve is controlled to open so that the lubricating oil and the refrigerant in the capillary network return to the compressor. The first preset condition is used to indicate that the liquid refrigerant accumulates in the capillary network to a preset value.

7. The control method according to claim 6, characterized in that, When performing the step of controlling the electronic expansion valve to open so that the lubricating oil and refrigerant in the capillary network return to the compressor, the control method further includes: The operating frequency of the compressor is controlled to be greater than or equal to a preset frequency threshold.

8. The control method according to claim 6, characterized in that, The control method further includes: Obtain the operating time of the air conditioning system in normal mode; When it is determined that the air conditioning system has been running in normal mode for a first preset duration, the air conditioning system is controlled to enter the oil return mode.

9. The control method according to any one of claims 6-8, characterized in that, The control method further includes: When the operating parameters are determined to meet the second preset condition, the air conditioning system is controlled to exit the oil return mode. The second preset condition is used to indicate that the liquid refrigerant and the lubricating oil in the capillary network have flowed out.

10. A control device for an air conditioning system, applied to the air conditioning system as described in any one of claims 1 to 5, characterized in that, The control device includes: The control module is used to control the electronic expansion valve connected in series with the capillary network to close when the air conditioning system enters the oil return mode, so that the refrigerant accumulates and condenses into a liquid state in the capillary network, wherein the lubricating oil remaining in the capillary network is miscible with the liquid refrigerant. The acquisition module is used to acquire the operating parameters of the air conditioning system, which are obtained by the detection device of the air conditioning system. The control module is also used to control the electronic expansion valve to open so that the lubricating oil and refrigerant in the capillary network return to the compressor when the operating parameters meet the first preset condition. The first preset condition is used to indicate that the liquid refrigerant accumulates in the capillary network to a preset value.

11. An air conditioning device, characterized in that, It includes a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the steps of the method according to any one of claims 6-9.

Images