Method for controlling the self-cleaning of the tubes of a room heat exchanger

Abstract

The present application relates to the air conditioning technical field, specifically to a kind of indoor heat exchanger's pipe inside self-cleaning control method.The present application aims to solve the problem that carbonization is easily accumulated in the interior of heat exchanger, which leads to the decline of heat exchange effect.For this purpose, the outdoor heat exchanger of the air conditioner of the present application includes multiple heat exchange pipe sections, and the outdoor heat exchanger is also provided with a on-off valve group, which includes multiple on-off valves, and the on-off valve group is arranged to be able to control the communication form between the multiple heat exchange pipe sections.The control method includes: controlling the air conditioner to operate in heating mode;controlling the on-off valve group to operate in a preset opening and closing mode, so that the refrigerant does not pass through the heat exchange pipe sections of the outdoor heat exchanger and directly flows back to the compressor of the air conditioner.The present application can realize efficient self-cleaning of the indoor heat exchanger, reduce the length and resistance of the refrigerant flow during the self-cleaning process, and the self-cleaning process has fast flow rate, small pressure drop, large flow, high carbonization removal efficiency, and there is no problem of secondary pollution of the outdoor heat exchanger during the self-cleaning process.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and more specifically to a control method for an indoor heat exchanger. Background Technology

[0002] Air conditioners are playing an increasingly important role in household appliances, and their operating efficiency has a crucial impact on household living costs. Therefore, ensuring the effective operation of air conditioners and improving their efficiency has become a pressing issue for manufacturers.

[0003] During long-term operation of an air conditioner, the refrigerant oil inside the compressor circulates with the refrigerant. Under high temperatures, the oil slowly carbonizes, releasing trace amounts of carbon deposits. These carbon deposits easily adhere to the copper tube walls inside the heat exchanger. Additionally, carbon molecules in the refrigerant react with metals, releasing trace amounts of carbon deposits that also adhere to the inner walls of the copper tubes in the heat exchanger. If these carbon deposits are not cleaned promptly and returned to the compressor's dust collection ring, they will affect the heat exchange area between the refrigerant and the copper tubes, increasing thermal resistance, reducing the heat transfer coefficient, and ultimately impacting the heat exchange effect, leading to a decrease in the air conditioner's operating performance and efficiency.

[0004] Accordingly, there is a need in this field for a new technical solution to address the aforementioned problems. Summary of the Invention

[0005] To address at least one of the aforementioned problems in the prior art, namely, to solve the problem of carbon deposits easily accumulating inside the heat exchanger leading to a decrease in heat exchange efficiency, this application provides a self-cleaning control method for the tubes of an indoor heat exchanger, applied to an air conditioner. The outdoor heat exchanger of the air conditioner includes multiple heat exchange tube sections, and the outdoor heat exchanger is also equipped with an on / off valve assembly. The on / off valve assembly includes multiple on / off valves, and the on / off valve assembly is configured to control the connection between the multiple heat exchange tube sections.

[0006] The control method includes:

[0007] Control the air conditioner to operate in heating mode;

[0008] The on / off valve group is controlled to operate in a preset opening / closing mode so that the refrigerant flows directly back to the air conditioner compressor without passing through the heat exchange tube section of the outdoor heat exchanger.

[0009] In a preferred embodiment of the above-mentioned self-cleaning control method for the indoor heat exchanger, the outdoor heat exchanger includes a first heat exchange tube section, a second heat exchange tube section, and a third heat exchange tube section connected in sequence. The outdoor heat exchanger also includes a first branch pipe, a second branch pipe, and a third branch pipe. The first end of the first branch pipe is connected to a refrigerant pipe between the air conditioner's compressor and the first heat exchange tube section. The second end of the first branch pipe is connected to a refrigerant pipe between the second and third heat exchange tube sections. The first end of the second branch pipe is connected to the third branch pipe and is connected to the end of the third heat exchange tube section closest to the second heat exchange tube section. The first end of the third branch pipe is connected to a refrigerant pipe between the first and second heat exchange tube sections. The second end of the third branch pipe is connected to a refrigerant pipe between the third heat exchange tube section and the air conditioner's throttling element.

[0010] The on / off valve group includes a first on / off valve, a second on / off valve, a third on / off valve, and a fourth on / off valve. The first on / off valve is located on the first branch pipe. The second on / off valve is located on the refrigerant pipe between the second heat exchange pipe section and the third heat exchange pipe section and is situated between the second end of the first branch pipe and the third heat exchange pipe section. The third on / off valve is located on the second branch pipe. The fourth on / off valve is located on the third branch pipe and is situated between the first end of the second branch pipe and the second end of the third branch pipe.

[0011] In the preferred embodiment of the above-mentioned self-cleaning control method for the tubes of the indoor heat exchanger, the step of "controlling the on / off valve group to operate in a preset opening / closing mode" further includes:

[0012] The first on / off valve, the second on / off valve, the third on / off valve, and the fourth on / off valve are all opened.

[0013] In the preferred embodiment of the above-mentioned self-cleaning control method for the pipes of the indoor heat exchanger, the compressor of the air conditioner is a variable displacement compressor, the variable displacement compressor has two compression cylinders, and the control method further includes:

[0014] Control the variable capacity compressor to operate in two-stage mode;

[0015] The variable capacity compressor operates in two modes: a dual-cylinder mode and a two-stage mode. In the dual-cylinder mode, the two compression cylinders of the variable capacity compressor compress the refrigerant individually. In the two-stage mode, the two compression cylinders of the variable capacity compressor compress the refrigerant sequentially.

[0016] In the preferred embodiment of the above-mentioned self-cleaning control method for the indoor heat exchanger, the indoor heat exchanger of the air conditioner includes an independent internal heat exchange pipeline and an external heat exchange pipeline. The first end of the internal heat exchange pipeline and the first end of the external heat exchange pipeline are respectively connected to the throttling element of the air conditioner through a first liquid pipe and a second liquid pipe. The second ends of the internal heat exchange pipeline and the external heat exchange pipeline are respectively connected to the compressor of the air conditioner through a first gas pipe and a second gas pipe.

[0017] In a preferred embodiment of the above-mentioned self-cleaning control method for the tubes of an indoor heat exchanger, the second air pipe can be selectively connected or blocked, and the first air pipe and the second air pipe can be selectively connected or blocked. The control method further includes:

[0018] Control the connection of the second trachea and block the connection between the first trachea and the second trachea.

[0019] In a preferred embodiment of the above-mentioned self-cleaning control method for the tubes of an indoor heat exchanger, the first liquid tube can be selectively connected or disconnected, and the first liquid tube and the second liquid tube can be selectively connected or disconnected. The control method further includes:

[0020] Control the connection of the first liquid pipe, and block the connection between the first liquid pipe and the second liquid pipe.

[0021] In a preferred embodiment of the above-mentioned self-cleaning control method for the tubes of an indoor heat exchanger, the control method further includes:

[0022] While controlling the on / off valve group to operate in the preset opening / closing mode, before, or after, control the air conditioner compressor to operate at the highest frequency;

[0023] After the compressor runs at the highest frequency for a first preset time, it is controlled to run at the frequency before self-cleaning.

[0024] In a preferred embodiment of the above-mentioned self-cleaning control method for the tubes of an indoor heat exchanger, the control method further includes:

[0025] During the self-cleaning process, the throttling element of the air conditioner is fully open.

[0026] In a preferred embodiment of the above-mentioned self-cleaning control method for the tubes of an indoor heat exchanger, the control method further includes:

[0027] If the air conditioner is operating in cooling mode before performing self-cleaning, the internal fan of the air conditioner is controlled to stop operating at the same time as or before entering self-cleaning.

[0028] The control method of this application controls the air conditioner to operate in heating mode and controls the on / off valve group to operate in a preset opening and closing mode, so that the refrigerant does not pass through the heat exchange tube section of the outdoor heat exchanger during the self-cleaning process, but only circulates between the compressor and the indoor heat exchanger. This can achieve efficient self-cleaning of the indoor heat exchanger, reduce the refrigerant flow length and resistance in the self-cleaning process, and the self-cleaning process has a fast flow rate, low pressure drop, large flow rate, and high carbon removal efficiency. Moreover, there is no problem of secondary pollution of the outdoor heat exchanger during the self-cleaning process. Attached Figure Description

[0029] The present application will now be described with reference to the accompanying drawings. In the drawings:

[0030] Figure 1 This is a system diagram of the air conditioner in the two-stage compressor operation mode of this application;

[0031] Figure 2 This is a system diagram of the air conditioner of this application in the dual-cylinder compressor operation mode;

[0032] Figure 3 This is a flowchart of the self-cleaning control method for the pipes of the outdoor heat exchanger of the air conditioner according to this application.

[0033] List of reference numerals

[0034] 1. Compressor; 11. First compression cylinder; 12. Second compression cylinder; 13. First port; 14. Second port; 15. Third port; 16. Fourth port; 17. Exhaust port; 2. Second four-way valve; 3. Outdoor heat exchanger; 31. First heat exchange tube section; 32. Second heat exchange tube section; 33. Third heat exchange tube section; 34. First branch pipe; 35. Second branch pipe; 36. Third branch pipe; 4. Throttling element; 5. Indoor heat exchanger; 51. Internal exhaust heat exchange pipe; 511. 512. Second internal heat exchanger section; 52. External heat exchanger pipeline; 521. First external heat exchanger section; 522. Second external heat exchanger section; 61. First liquid pipe; 62. Second liquid pipe; 63. First gas pipe; 64. Second gas pipe; 71. First three-way control valve; 72. Second three-way control valve; 81. First shut-off valve; 82. Second shut-off valve; 83. Third shut-off valve; 84. Fourth shut-off valve; 9. First four-way valve; 10. Gas-liquid separator. Detailed Implementation

[0035] Preferred embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application. For example, although the detailed steps of the method of this application are described in detail below, those skilled in the art can combine, split, and rearrange the following steps without departing from the basic principles of this application. Such modified technical solutions do not change the basic concept of this application and therefore also fall within the scope of protection of this application.

[0036] It should be noted that in the description of this application, terms such as "upper," "lower," "left," and "right," indicating directional or positional relationships, are based on the directional or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Additionally, in the description of this application, "a plurality of" refers to at least two.

[0037] Furthermore, it should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] First refer to Figure 1 and Figure 2 The air conditioner described in this application is described below.

[0039] like Figure 1 and Figure 2 As shown, the air conditioner of this application includes a compressor 1, a second four-way valve 2, an outdoor heat exchanger 3, a throttling element 4, and an indoor heat exchanger 5. The compressor 1, the second four-way valve 2, the outdoor heat exchanger 3, the throttling element 4, and the indoor heat exchanger 5 are sequentially connected via refrigerant pipes to form a refrigerant circulation system. Preferably, the throttling element 4 is an electronic expansion valve. The above connection method and the working principle of the air conditioner are conventional techniques in the field and will not be described in detail here.

[0040] Specifically, the outdoor heat exchanger 3 of this application includes multiple heat exchange tube sections, and an on / off valve assembly is also provided within the outdoor heat exchanger 3. The on / off valve assembly includes multiple on / off valves and is configured to control the connection between the multiple heat exchange tube sections. Specifically, the outdoor heat exchanger 3 includes a first heat exchange tube section 31, a second heat exchange tube section 32, and a third heat exchange tube section 33 connected in sequence. The first heat exchange tube section 31 is located in the middle of the outdoor heat exchanger 3, the second heat exchange tube section 32 is located above the first heat exchange tube section 31, and the third heat exchange tube section 33 is located below the first heat exchange tube section 31. One end of the first heat exchange tube section 31 is connected to the exhaust port 17 of the compressor 1 through a refrigerant pipe, the other end of the first heat exchange tube section 31 is connected to one end of the second heat exchange tube section 32 through a refrigerant pipe, the other end of the second heat exchange tube section 32 is connected to one end of the third heat exchange tube section 33 through a refrigerant pipe, and the other end of the third heat exchange tube section 33 is connected to the throttling element 4 through a refrigerant pipe.

[0041] The outdoor heat exchanger 3 also includes a first branch pipe 34, a second branch pipe 35, and a third branch pipe 36. The first end of the first branch pipe 34 is connected to the refrigerant pipe between the compressor 1 and the first heat exchange tube section 31, and the second end of the first branch pipe 34 is connected to the refrigerant pipe between the second heat exchange tube section 32 and the third heat exchange tube section 33. The first end of the second branch pipe 35 is connected to the third branch pipe 36, and the second end of the second branch pipe 35 is connected to the end of the third heat exchange tube section 33 closest to the second heat exchange tube section 32 (i.e., the end where the third heat exchange tube section 33 connects to the second heat exchange tube section 32). The first end of the third branch pipe 36 is connected to the refrigerant pipe between the first heat exchange tube section 31 and the second heat exchange tube section 32, and the second end of the third branch pipe 36 is connected to the refrigerant pipe between the third heat exchange tube section 33 and the throttling element 4.

[0042] The on / off valve assembly includes a first on / off valve 81, a second on / off valve 82, a third on / off valve 83, and a fourth on / off valve 84. Preferably, the first on / off valve 81, the second on / off valve 82, the third on / off valve 83, and the fourth on / off valve 84 are all solenoid valves. Specifically, the first on / off valve 81 is located on the first branch pipe 34, the second on / off valve 82 is located on the refrigerant pipe between the second heat exchange pipe section 32 and the third heat exchange pipe section 33, and is situated between the second end of the first branch pipe 34 and the third heat exchange pipe section 33, the third on / off valve 83 is located on the second branch pipe 35, and the fourth on / off valve 84 is located on the third branch pipe 36, situated between the first end of the second branch pipe 35 and the second end of the third branch pipe 36.

[0043] Under the above configuration, by controlling the opening and closing of the first on / off valve 81, the second on / off valve 82, the third on / off valve 83 and the fourth on / off valve 84, different connection forms of the first heat exchange tube section 31, the second heat exchange tube section 32 and the third heat exchange tube section 33 can be realized, thereby achieving different flow diversion effects of the outdoor heat exchanger 3.

[0044] See also Figure 1and Figure 2 Preferably, the indoor heat exchanger 5 includes an independent internal heat exchange pipe 51 and an external heat exchange pipe 52. The first end of the internal heat exchange pipe 51 and the first end of the external heat exchange pipe 52 are respectively connected to the throttling element 4 through a first liquid pipe 61 and a second liquid pipe 62. The second ends of the internal heat exchange pipe 51 and the external heat exchange pipe 52 are respectively connected to the second four-way valve 2 through a first air pipe 63 and a second air pipe 64. Preferably, the second air pipe 64 can be selectively connected or blocked, and the first air pipe 63 and the second air pipe 64 can be selectively connected or blocked. More preferably, a first three-way control valve 71 is provided on the second air pipe 64, and the first port 13 of the first three-way control valve 71 ( Figure 1 (shown on the left end), second port 14 ( Figure 1 (shown on the right end) and the third port 15 ( Figure 1 The upper end shown is respectively connected to the second end of the external heat exchange pipeline 52, the second four-way valve 2, and the first gas pipe 63. Preferably, the first liquid pipe 61 can be selectively connected or blocked, and the first liquid pipe 61 and the second liquid pipe 62 can be selectively connected or blocked. More preferably, a second three-way control valve 72 is provided on the first liquid pipe 61, and the first port 13 of the second three-way control valve 72 ( Figure 1 (shown on the left end), second port 14 ( Figure 1 (shown on the right end) and the third port 15 ( Figure 1 The lower end shown is connected to the throttling element 4, the first end of the internal heat exchange pipeline 51, and the second liquid pipe 62, respectively.

[0045] Reference Figure 1 and Figure 2 In this application, the internal heat exchange pipeline 51 includes a first internal heat exchange pipeline segment 511 and a second internal heat exchange pipeline segment 512. The first end of the first internal heat exchange pipeline segment 511 and the first end of the second internal heat exchange pipeline segment 512 are simultaneously connected to the first liquid pipeline 61, and the second end of the first internal heat exchange pipeline segment 511 and the second end of the second internal heat exchange pipeline segment 512 are simultaneously connected to the first gas pipeline 63. The external heat exchange pipeline 52 includes a first external heat exchange pipeline segment 521 and a second external heat exchange pipeline segment 522. The first end of the first external heat exchange pipeline segment 521 and the first end of the second external heat exchange pipeline segment 522 are simultaneously connected to the second liquid pipeline 62, and the second end of the first external heat exchange pipeline segment 521 and the second end of the second external heat exchange pipeline segment 522 are simultaneously connected to the second gas pipeline 64.

[0046] In a preferred embodiment, the compressor 1 is a variable displacement compressor 1, which has two compression cylinders. Specifically, the variable displacement compressor 1 has a first compression cylinder 11 and a second compression cylinder 12 inside. The compressor 1 housing has four ports and an exhaust port 17. The first port 13 is connected to the air inlet of the first compression cylinder 11, the second port 14 is connected to the air outlet of the first compression cylinder 11, the third port 15 is connected to the air inlet of the second compression cylinder 12, the air outlet of the second compression cylinder 12 is connected to the exhaust port 17, and the fourth port 16 is connected to the exhaust port 17 through the inside of the housing.

[0047] The variable displacement compressor 1 is also equipped with a first four-way valve 9, which has four ports a, b, c, and d. Port a is connected to the fourth port 16, port b is connected to the second port 14, and port c is connected to the third port 15. A moving part is installed inside the first four-way valve 9. When the first four-way valve 9 is energized or de-energized, the moving part moves within the first four-way valve 9 to achieve connection and disconnection between different ports.

[0048] The second four-way valve 2 is connected to two gas-liquid separators 10, and the outlets of the two gas-liquid separators 10 are respectively connected to the two compression cylinders of the variable displacement compressor 1. Among them, the outlet of one gas-liquid separator 10 is directly connected to the first port 13, and the outlet of the other gas-liquid separator 10 is connected through the fourth interface d of the first four-way valve 9, thereby indirectly achieving connection with the third port 15.

[0049] Under the above configuration, the variable displacement compressor 1 operates in two-cylinder and two-stage modes. See also... Figure 1 When the first four-way valve 9 is powered on, it operates in two-stage mode. In this mode, the two compression cylinders of the variable capacity compressor 1 compress the refrigerant sequentially. Specifically, the first port a and the fourth port d of the first four-way valve 9 are separated by a moving part. The refrigerant discharged from the outdoor heat exchanger 3 passes through one of the gas-liquid separators 10 and then enters the first compression cylinder 11 through the first port 13. After being compressed by the first compression cylinder 11, it is discharged through the second port 14. Then, after passing through the second port b and the third port c of the first four-way valve 9, it enters the second compression cylinder 12 through the third port 15. After secondary compression by the second compression cylinder 12, it is discharged through the exhaust port 17. In this mode, the variable capacity compressor 1 can achieve a higher compression ratio at a lower operating frequency, thereby meeting the condensing temperature requirements and ensuring the air conditioning cooling effect and efficiency.

[0050] See Figure 2Conversely, when the first four-way valve 9 is de-energized, it operates in dual-cylinder mode. In this mode, the two compression cylinders of the variable-capacity compressor 1 compress the refrigerant independently. Specifically, a portion of the refrigerant discharged from the outdoor heat exchanger 3 passes through one of the gas-liquid separators 10 and enters the first compression cylinder 11 through the first port 13. After being compressed by the first compression cylinder 11, it is discharged through the second port 14, then passes through the second port b and the first port a of the first four-way valve 9 into the housing and is finally discharged through the exhaust port 17. The other portion of the refrigerant passes through the other gas-liquid separator 10, then passes through the fourth port d and the third port c of the first four-way valve 9, and then enters the second compression cylinder 12 through the third port 15. After being compressed by the second compression cylinder 12, it is discharged through the exhaust port 17. The variable-capacity compressor 1 uses a dual-cylinder mode, resulting in a lower frequency for the same discharge capacity. This leads to lower high pressure and higher low pressure in the air conditioning system, reducing the compression ratio of the compressor 1.

[0051] Those skilled in the art will understand that the above-described air conditioner configuration is merely a preferred embodiment. They can adjust the structure of the air conditioner without departing from the principles of this application to make it applicable to more specific application scenarios. For example, although the air conditioner is described in conjunction with the inclusion of a second four-way valve 2, this implementation is not fixed. In other embodiments, those skilled in the art can selectively omit the second four-way valve 2, making the air conditioner a cooling-only unit. Furthermore, the specific form of the throttling element 4 is not limited in this application; it can also be a capillary tube or a thermostatic expansion valve, etc. Moreover, those skilled in the art can adapt and adjust the number and configuration of the heat exchange tubes in the outdoor heat exchanger 3, the number and connection methods of the branch pipes, and the number and location of the on / off valves in the on / off valve group to make this application applicable to more specific application scenarios. For example, those skilled in the art can increase or decrease the number, location, and connection methods of the heat exchange tubes; or, they can increase or decrease the number and connection relationships of the branch pipes; or, they can increase or decrease the number and location of the on / off valves. In summary, as long as the connection mode of the heat exchange tube section can be adjusted by controlling the opening and closing of the on / off valves in the on / off valve group, such changes do not deviate from the principle of this application. For example, although the compressor 1 described above is in conjunction with a variable displacement compressor 1, this is not mandatory; a conventional compressor 1 can also be used. Furthermore, the switching between the two-cylinder mode and the two-stage mode of the variable displacement compressor 1 can be achieved not through the first four-way valve 9, but by setting multiple valve groups and controlling the opening and closing of each valve within the valve group. Furthermore, the specific structural form of the variable displacement compressor 1 is not fixed. Provided that the switching between the two-cylinder mode and the two-stage mode can be achieved, those skilled in the art can adjust the structure of the variable displacement compressor 1, such as changing the number, position, and connection relationship of ports. Furthermore, the gas-liquid separator 10 is not mandatory; those skilled in the art can select it according to specific needs. Furthermore, the selective connection or disconnection of the second gas pipe 64 and the selective connection or disconnection between the first gas pipe 63 and the second gas pipe 64 can also be achieved using two separate solenoid valves. Similarly, the selective connection or disconnection of the first liquid pipe 61, and the selective connection or disconnection between the first liquid pipe 61 and the second liquid pipe 62, can also be achieved using two separate solenoid valves. Furthermore, the specific structure of the indoor heat exchanger 5 is not fixed and can be adjusted by those skilled in the art; for example, the number of internal exhaust heat exchange pipes 51 and external exhaust heat exchange pipes 52 can be increased. Moreover, the specific composition of the internal exhaust heat exchange pipes 51 and external exhaust heat exchange pipes 52 is not unique; those skilled in the art can select the number of heat exchange pipe segments included in the selector based on the specific application scenario, and the number of connecting pipes also needs to be adjusted accordingly.

[0052] The following reference Figure 3This paper introduces the self-cleaning control method for the tubes of the indoor heat exchanger of this application.

[0053] like Figure 3 As shown, in order to solve the problem of carbon deposits easily accumulating inside the heat exchanger, leading to a decrease in heat exchange efficiency, the self-cleaning control method for the tubes of the indoor heat exchanger in this application includes:

[0054] S101 controls the air conditioner to operate in heating mode. For example, after entering self-cleaning mode, the air conditioner needs to be switched to heating mode regardless of its previous operating mode.

[0055] S103 controls the on / off valve assembly to operate in a preset opening / closing mode, so that the refrigerant flows directly back to the air conditioner compressor without passing through the heat exchange tubes of the outdoor heat exchanger. For example, by controlling the opening and closing of each on / off valve in the on / off valve assembly, the high-temperature and high-pressure refrigerant discharged from the compressor first enters the indoor heat exchanger, flushing the inner wall of the copper tubes of the indoor heat exchanger, causing the carbides attached to the copper tube wall to loosen and fall off. Then, the fallen carbides, along with the high-temperature refrigerant, pass through the throttling element and, without passing through the heat exchange tubes of the outdoor heat exchanger, that is, without exchanging heat with the outdoor air, flow directly back to the air conditioner compressor.

[0056] The control method of this application controls the air conditioner to operate in heating mode and controls the on / off valve group to operate in a preset opening and closing mode, so that the refrigerant does not pass through the heat exchange tube section of the outdoor heat exchanger during the self-cleaning process, but only circulates between the compressor and the indoor heat exchanger. This can achieve efficient self-cleaning of the indoor heat exchanger, reduce the refrigerant flow length and resistance in the self-cleaning process, and the self-cleaning process has a fast flow rate, low pressure drop, large flow rate, and high carbon removal efficiency. Moreover, there is no problem of secondary pollution of the outdoor heat exchanger during the self-cleaning process.

[0057] The preferred embodiments of the self-cleaning control method for the tubes of the indoor heat exchanger of this application are described below.

[0058] In a preferred embodiment, the step of “controlling the on-off valve group to operate in a preset opening and closing mode” further includes: controlling the first on-off valve, the second on-off valve, the third on-off valve and the fourth on-off valve to open.

[0059] Specifically, with the first, second, third, and fourth shut-off valves all open, the refrigerant discharged from the compressor first passes through the indoor heat exchanger, and then, after being discharged from the indoor heat exchanger, it reaches the outdoor heat exchanger through the throttling element. Since all four shut-off valves are open, the refrigerant flows back to the compressor after passing through the fourth, third, second, and first shut-off valves in sequence, without passing through the first, second, and third heat exchanger tube sections. This reduces the refrigerant's flow length and resistance, resulting in a faster refrigerant flow rate, lower pressure drop, larger flow rate, and higher efficiency in carrying away carbon deposits, thus avoiding secondary pollution of the outdoor heat exchanger by carbon deposits.

[0060] In one embodiment, the control method further includes controlling the variable capacity compressor to operate in a two-stage mode.

[0061] Specifically, before self-cleaning, regardless of the compressor's operating mode, the variable displacement compressor is controlled to operate in two-stage mode during the self-cleaning process. In this mode, the two compression cylinders of the variable displacement compressor compress the refrigerant sequentially. Specifically, the first port a and the fourth port d of the first four-way valve are separated by a moving part. The refrigerant discharged from the outdoor heat exchanger passes through one of the gas-liquid separators and enters the first compression cylinder via the first port. After compression by the first compression cylinder, it is discharged through the second port. Then, after passing through the second port b and the third port c of the first four-way valve, it enters the second compression cylinder through the third port. After secondary compression by the second compression cylinder, it is discharged through the exhaust port. In this mode, the variable displacement compressor can achieve a higher compression ratio at a lower operating frequency, thereby meeting the high temperature and high pressure requirements of the refrigerant and improving the self-cleaning effect within the pipes.

[0062] Of course, the above control steps are merely preferred options, and those skilled in the art can adjust them. For example, when the compressor is a conventional compressor, those skilled in the art can choose to achieve the high temperature and high pressure requirements of the refrigerant by controlling the compressor frequency, etc.

[0063] In one embodiment, the control method further includes: controlling the second trachea to be connected and blocking the connection between the first trachea and the second trachea; controlling the first liquid tube to be connected and blocking the connection between the first liquid tube and the second liquid tube.

[0064] Specifically, during the self-cleaning process, the three-way control valve is adjusted so that the first port of the first three-way control valve is connected to the second port, while the third port is blocked, thereby opening the second gas pipe and blocking the connection between the first and second gas pipes. The second three-way control valve is then adjusted so that the first port is connected to the second port, while the third port is blocked, thereby opening the first liquid pipe and blocking the connection between the first and second liquid pipes. At this time, after being discharged from the compressor, the refrigerant is divided into two paths, flowing through the first gas pipe and the second gas pipe respectively into the internal and external heat exchange pipes of the indoor heat exchanger for heat exchange. After heat exchange, the refrigerant is divided into two paths, flowing through the first liquid pipe and the second liquid pipe respectively to the throttling element. This mode shortens the flow path of the refrigerant in the indoor heat exchanger, reduces the refrigerant pressure drop, and facilitates the rapid removal of dirt by the refrigerant, making the self-cleaning of the pipes fast and effective.

[0065] Of course, the above control method is not mandatory, and those skilled in the art can selectively omit this step. For example, if either the first three-way control valve or the second three-way control valve is replaced with other valves or valve assemblies, the control method can be adjusted accordingly, as long as the inlet and outlet paths of the refrigerant in the indoor heat exchanger are short and the pressure drop is small.

[0066] In one embodiment, the control method further includes: controlling the air conditioner compressor to operate at the highest frequency while, before, or after controlling the on-off valve group to operate in a preset on-off mode; and controlling the compressor to operate at the frequency before self-cleaning after the compressor has operated at the highest frequency for a first preset time.

[0067] Specifically, the first preset duration is 5 minutes. During the self-cleaning process, while the on / off valve group operates in the preset opening and closing mode, the compressor operates at the highest frequency for heating and in a two-stage mode. This maximizes the temperature and pressure of the discharged refrigerant, thereby improving the self-cleaning effect inside the pipes. After the compressor maintains this state for 5 minutes, the refrigerant has already flushed the internal and external heat exchange pipes of the indoor heat exchanger multiple times. At this point, the frequency is reduced to the frequency before self-cleaning, completing the self-cleaning of the indoor heat exchanger's pipes.

[0068] Of course, the specific value of the first preset duration is not unique, and those skilled in the art can adjust it to make this application applicable to more specific application scenarios. In addition, besides simultaneous operation, the compressor can also control the compressor regulation frequency before or after the on-off valve group operates in a preset opening and closing mode.

[0069] In one embodiment, the control method further includes: during the self-cleaning process, controlling the throttling element of the air conditioner to be fully open.

[0070] Specifically, when the throttling element is fully open, the refrigerant discharged from the indoor heat exchanger is not throttled by the throttling element, but returns directly to the compressor. This facilitates the rapid return of the refrigerant carrying away carbon deposits to the compressor, preventing carbon deposits from being throttled in the pipeline and improving the self-cleaning effect inside the pipeline.

[0071] Of course, controlling the throttling element to be fully open is only a preferred method, and those skilled in the art can choose to omit this step.

[0072] In one embodiment, the control method further includes: if the air conditioner is operating in cooling mode before performing self-cleaning, then controlling the indoor fan of the air conditioner to stop operating at the same time as or before entering self-cleaning.

[0073] Specifically, if the cooling mode is running before self-cleaning, the indoor unit will blow hot air after entering self-cleaning mode. To avoid affecting the user experience, the indoor fan will be stopped before entering self-cleaning mode. The indoor fan will be turned on again after self-cleaning is completed and the temperature of the indoor heat exchanger coil drops below the indoor temperature.

[0074] In one embodiment, the control method further includes: if the heating mode is running before self-cleaning, then after self-cleaning is completed, controlling the on-off valve group to reset to the open / closed state before self-cleaning; controlling the throttling element according to the target exhaust temperature, and starting the indoor fan when the indoor coil temperature drops to the anti-cold air temperature.

[0075] At the same time, the first and second ports of the first three-way control valve are connected, while the third port is blocked. The first port of the second three-way control valve is blocked, while the second and third ports are connected. At this time, the indoor heat exchanger splits into two inlets and one outlet, which not only meets the counter-current air intake requirement but also reduces the cold outlet temperature, preventing the indoor radiant heat exhaust from affecting the external exhaust heating.

[0076] Of course, the control methods described above after the self-cleaning process are merely exemplary and are not intended to limit the scope of protection of this application. Those skilled in the art can make adjustments based on specific needs.

[0077] Although the steps in the above embodiments are described in the above order, those skilled in the art will understand that in order to achieve the effect of this embodiment, different steps do not need to be executed in such order. They can be executed simultaneously (in parallel) or in reverse order. These simple changes are all within the protection scope of this application.

[0078] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, any of the claimed embodiments in the claims of this application can be used in any combination.

[0079] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A method for controlling the self-cleaning of the tubes of an indoor heat exchanger, applied to air conditioning, characterized in that, The outdoor heat exchanger of the air conditioner includes multiple heat exchange tube sections. The outdoor heat exchanger is also equipped with an on / off valve assembly, which includes multiple on / off valves. The on / off valve assembly is configured to control the connection between the multiple heat exchange tube sections. The control method includes: Control the air conditioner to operate in heating mode; The on / off valve group is controlled to operate in a preset opening and closing mode so that the refrigerant does not pass through the heat exchange tube section of the outdoor heat exchanger and flows directly back to the compressor of the air conditioner; The outdoor heat exchanger includes a first heat exchange tube section, a second heat exchange tube section, and a third heat exchange tube section connected in sequence. The outdoor heat exchanger also includes a first branch pipe, a second branch pipe, and a third branch pipe. A first end of the first branch pipe is connected to a refrigerant pipe between the air conditioner's compressor and the first heat exchange tube section. A second end of the first branch pipe is connected to a refrigerant pipe between the second and third heat exchange tube sections. A first end of the second branch pipe is connected to the third branch pipe, and a second end of the second branch pipe is connected to the end of the third heat exchange tube section closest to the second heat exchange tube section. A first end of the third branch pipe is connected to a refrigerant pipe between the first and second heat exchange tube sections. A second end of the third branch pipe is connected to a refrigerant pipe between the third heat exchange tube section and the air conditioner's throttling element. The on / off valve group includes a first on / off valve, a second on / off valve, a third on / off valve, and a fourth on / off valve. The first on / off valve is located on the first branch pipe. The second on / off valve is located on the refrigerant pipe between the second heat exchange pipe section and the third heat exchange pipe section and is situated between the second end of the first branch pipe and the third heat exchange pipe section. The third on / off valve is located on the second branch pipe. The fourth on / off valve is located on the third branch pipe and is situated between the first end of the second branch pipe and the second end of the third branch pipe.

2. The self-cleaning control method for the tubes of an indoor heat exchanger according to claim 1, characterized in that, The step of "controlling the on / off valve assembly to operate in a preset opening / closing mode" further includes: The first on / off valve, the second on / off valve, the third on / off valve, and the fourth on / off valve are all opened.

3. The self-cleaning control method for the tubes of an indoor heat exchanger according to claim 1, characterized in that, The air conditioner's compressor is a variable displacement compressor, which has two compression cylinders. The control method further includes: Control the variable capacity compressor to operate in two-stage mode; The variable capacity compressor operates in two modes: a dual-cylinder mode and a two-stage mode. In the dual-cylinder mode, the two compression cylinders of the variable capacity compressor compress the refrigerant individually. In the two-stage mode, the two compression cylinders of the variable capacity compressor compress the refrigerant sequentially.

4. The self-cleaning control method for the tubes of an indoor heat exchanger according to claim 1, characterized in that, The indoor heat exchanger of the air conditioner includes an independent internal heat exchange pipeline and an external heat exchange pipeline. The first end of the internal heat exchange pipeline and the first end of the external heat exchange pipeline are respectively connected to the throttling element of the air conditioner through a first liquid pipe and a second liquid pipe. The second ends of the internal heat exchange pipeline and the external heat exchange pipeline are respectively connected to the compressor of the air conditioner through a first gas pipe and a second gas pipe.

5. The self-cleaning control method for the tubes of an indoor heat exchanger according to claim 4, characterized in that, The second trachea can be selectively connected or blocked, and the first trachea and the second trachea can be selectively connected or blocked. The control method further includes: Control the connection of the second trachea and block the connection between the first trachea and the second trachea.

6. The self-cleaning control method for the tubes of an indoor heat exchanger according to claim 4, characterized in that, The first liquid tube can be selectively connected or disconnected, and the first liquid tube and the second liquid tube can be selectively connected or disconnected. The control method further includes: Control the connection of the first liquid pipe, and block the connection between the first liquid pipe and the second liquid pipe.

7. The self-cleaning control method for the tubes of an indoor heat exchanger according to claim 1, characterized in that, The control method further includes: While controlling the on / off valve group to operate in the preset opening / closing mode, before, or after, control the air conditioner compressor to operate at the highest frequency; After the compressor runs at the highest frequency for a first preset time, it is controlled to run at the frequency before self-cleaning.

8. The self-cleaning control method for the tubes of an indoor heat exchanger according to claim 1, characterized in that, The control method further includes: During the self-cleaning process, the throttling element of the air conditioner is fully open.

9. The self-cleaning control method for the tubes of an indoor heat exchanger according to claim 1, characterized in that, The control method further includes: If the air conditioner is operating in cooling mode before performing self-cleaning, the internal fan of the air conditioner is controlled to stop operating at the same time as or before entering self-cleaning.

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