Defrosting control method of air conditioner

Abstract

The invention provides a defrosting control method of an air conditioner. The defrosting control method comprises the steps that whether an outdoor heat exchanger needs to be defrosted or not is judged; and if yes, the refrigerant enters the outdoor heat exchanger and then enters the indoor heat exchanger, a first on-off device, a second on-off device, a fourth on-off device, a fifth on-off device, a sixth on-off device and an eighth on-off device are controlled to be in the on state, and a third on-off device and a seventh on-off device are controlled to be in the off state. The problem that an outdoor heat exchanger of an existing air conditioner is low in defrosting efficiency can be solved, the defrosting time can be shortened, and the user experience can be improved.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to a defrosting control method for air conditioners. Background Technology

[0002] When an air conditioner is in heating mode during winter, the outdoor heat exchanger acts as an evaporator, absorbing heat from the air. Its surface temperature is usually lower than the dew point of the ambient air, causing moisture in the air to continuously condense and freeze into frost. The frost layer severely hinders air circulation and heat exchange, leading to a significant decrease in system heating efficiency and an increase in energy consumption. Therefore, periodic defrosting is necessary.

[0003] Currently, conventional air conditioners generally use a fixed flow path design for their outdoor heat exchangers. The defrosting process typically requires the system to execute a "reverse cycle," that is, switch to cooling mode to direct the high-temperature gaseous refrigerant to the outdoor unit to melt the frost. This operation directly causes the indoor unit to stop heating and blow cold air into the indoor environment, causing indoor temperature fluctuations and severely impacting the user experience. Furthermore, due to the limitations of the fixed flow path structure, the refrigerant flow path and heat exchange area cannot be optimized according to the frost condition during defrosting, resulting in inefficient utilization of defrosting heat and a slow, prolonged defrosting process. This problem is particularly pronounced in low-temperature, high-humidity environments, becoming a major technical bottleneck affecting user experience. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide a defrosting control method for an air conditioner that overcomes or at least partially solves the above problems, and can solve the problem of low defrosting efficiency of the outdoor heat exchanger of existing air conditioners, so as to shorten the defrosting time and improve the user experience.

[0005] Specifically, the present invention provides a defrosting control method for an air conditioner, the air conditioner including an outdoor heat exchanger and an indoor heat exchanger. The outdoor heat exchanger includes: The first tube has a first port, a plurality of second ports, a third port and a fourth port arranged sequentially along its extension direction; a first switching device is arranged between every two adjacent second ports, a second switching device is arranged between the last second port and the third port, and a third switching device is arranged between the third port and the fourth port. The second tube has a plurality of fifth, sixth, seventh and eighth ports arranged sequentially along its extension direction; a fourth switching device is arranged between every two adjacent fifth ports; a fifth switching device is arranged between the last fifth port and the sixth port, and a sixth switching device is arranged between the sixth port and the seventh port. Multiple heat exchange tubes, including multiple first heat exchange tubes and multiple second heat exchange tubes; each first heat exchange tube is disposed between a second port and a fifth port; the second heat exchange tube is disposed between a third port and a seventh port; The fourth port is connected to the seventh port; the sixth port is connected to the end of the second heat exchange tube furthest from the seventh port; a seventh on / off device is provided on the pipeline between the sixth port and the corresponding end of the second heat exchange tube; an eighth on / off device is provided on the pipeline between the third port and the corresponding end of the second heat exchange tube; the eighth port is connected to the indoor heat exchanger through a throttling device. The defrosting control method includes: Determine whether the outdoor heat exchanger needs defrosting; If so, the refrigerant enters the outdoor heat exchanger first and then the indoor heat exchanger, and the first, second, fourth, fifth, sixth, and eighth on / off devices are all in the conducting state, while the third and seventh on / off devices are in the off state.

[0006] Optionally, a plurality of the first heat exchange tubes and the second heat exchange tubes are arranged sequentially along the length or width direction of the outdoor heat exchanger; The defrosting control method further includes: Obtain the number of defrosted areas in the respective regions of each of the multiple heat exchange tubes; When the number is greater than or equal to a preset number, the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device are controlled so that no refrigerant passes through the heat exchange tubes corresponding to areas that have been partially or completely defrosted.

[0007] Optionally, when the number is greater than or equal to a preset number, controlling the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device to ensure that no refrigerant passes through the heat exchange tubes corresponding to areas that have been partially or completely defrosted includes: Control the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device so that the refrigerant only passes through the heat exchange tube corresponding to the area that has not been defrosted.

[0008] Optionally, the preset number is the number of heat exchange tubes minus two; The number of the second port is four, the number of the fifth port is four; the number of the first heat exchange tubes is four; The plurality of first switching devices are a first control valve, a second control valve, and a third control valve arranged sequentially along the extension direction of the first pipe; The plurality of fourth on / off devices are respectively a fourth control valve, a fifth control valve, and a sixth control valve arranged sequentially along the extension direction of the first pipe.

[0009] Optionally, a temperature detection device is provided on each corresponding area of ​​the plurality of heat exchange tubes to determine, at least based on the detected temperature, whether defrosting has been completed on each corresponding area of ​​the heat exchange tubes; or Each of the heat exchange tubes is equipped with a temperature detection device on its corresponding outlet pipe to determine whether defrosting has been completed in the area corresponding to each heat exchange tube, based at least on the detected temperature.

[0010] Optionally, the defrosting control method for the air conditioner is characterized by further comprising: When the outdoor heat exchanger does not require defrosting, the degree of frost formation on the outdoor heat exchanger is obtained; Based on the degree of frost formation, the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device are controlled so that the number of refrigerants that directly enter the heat exchange tube through the eighth port corresponds to the degree of frost formation.

[0011] Optionally, controlling the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device according to the degree of frost includes: When the degree of frost increases, control the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device to increase the number of refrigerants that directly enter the heat exchange tube through the eighth port; When the degree of frost decreases, control the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device to reduce the number of refrigerants that directly enter the heat exchange tube through the eighth port.

[0012] Optionally, controlling the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device according to the degree of frost includes: After the frosting reaches the preset frosting level, the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device are controlled to gradually increase the number of refrigerants that directly enter the heat exchange tube through the eighth port.

[0013] Optionally, when the outdoor heat exchanger does not require defrosting, the defrosting control method further includes: Obtain the amount of frost on each corresponding area of ​​the heat exchange tube; When controlling the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device according to the degree of frost, the refrigerant is also allowed to directly enter the heat exchange tube through the eighth port, including the heat exchange tube corresponding to the area with the largest amount of frost.

[0014] Optionally, the defrosting control method further includes: Before the outdoor heat exchanger needs to be defrosted, the amount of frost on each area of ​​the heat exchange tube is obtained by pre-setting the time. Control the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device so that the refrigerant directly enters the heat exchange tube, including the heat exchange tube corresponding to the area with the largest amount of frost, through the eighth port.

[0015] In the defrosting control method of the air conditioner of the present invention, based on a variable flow outdoor heat exchanger, multiple heat exchange tubes of the outdoor heat exchanger form a parallel flow path during defrosting, so that the defrosting heat can evenly and quickly cover the entire surface of the heat exchanger, greatly shortening the defrosting time. This not only reduces energy waste, but more importantly, it minimizes the time that the indoor unit stops heating due to defrosting, effectively avoiding significant fluctuations in indoor temperature and significantly improving the user's heating comfort experience in severe winter.

[0016] Furthermore, in the defrosting control method of the air conditioner of the present invention, the air conditioner monitors the defrosting status of each area in real time during the defrosting process. When the number of areas that have been defrosted is greater than or equal to a preset number, the air conditioner readjusts the state of each on / off device to cut off or reduce the refrigerant flowing to the defrosted areas, which can further improve defrosting efficiency, save energy, and prevent the defrosted areas from being overheated, which is conducive to quickly restoring the heating mode after defrosting.

[0017] Furthermore, in the defrosting control method of the air conditioner of the present invention, the advantages of variable flow path technology are extended from the defrosting stage to the entire heating process. This achieves "on-demand defrosting" and "preventive defrosting," intervening in the early stages of frost formation to effectively delay the onset of severe frost, keeping the machine operating within its high-efficiency range, and improving overall heating efficiency and stability.

[0018] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0019] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic flowchart of a defrosting control method for an air conditioner according to an embodiment of the present invention; Figure 2 This is a schematic flowchart of a defrosting control method for an air conditioner according to an embodiment of the present invention; Figure 3 This is a schematic flowchart of a defrosting control method for an air conditioner according to an embodiment of the present invention; Figure 4 This is a schematic flowchart of a defrosting control method for an air conditioner according to an embodiment of the present invention; Figure 5 This is a schematic flowchart of a defrosting control method for an air conditioner according to an embodiment of the present invention; Figure 6 This is a schematic structural diagram of the outdoor heat exchanger of an air conditioner according to an embodiment of the present invention. Detailed Implementation

[0020] The following reference Figures 1 to 6This invention describes a defrosting control method for an air conditioner according to an embodiment of the present invention. In this description, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature, that is, include one or more of that feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. When a feature "includes or contains" one or more of the features it encompasses, unless otherwise specifically described, this indicates that other features are not excluded and may be further included.

[0021] Unless otherwise expressly specified and limited, the terms "set up," "install," "connect," "link," "fix," and "couple" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art should be able to understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] Furthermore, in the description of this embodiment, "above" or "below" the second feature can include direct contact between the first and second features, or it can include contact between the first and second features through another feature between them. That is, in the description of this embodiment, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "below" of the second feature can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] In the description of this embodiment, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0024] Figure 1 This is a schematic flowchart of a defrosting control method for an air conditioner according to an embodiment of the present invention, as shown below. Figure 1 As shown, and with reference Figures 2 to 6 This invention provides a defrosting control method for an air conditioner. The air conditioner includes an outdoor heat exchanger 1 and an indoor heat exchanger; the outdoor heat exchanger 1 includes a first pipe 10, a second pipe 20, and a plurality of heat exchange tubes.

[0025] The first pipe 10 is provided with a first port 11, a plurality of second ports 12, a third port 13 and a fourth port 14 in sequence along its extension direction; a first switching device is provided between every two adjacent second ports 12, a second switching device 52 is provided between the last second port 12 and the third port 13, and a third switching device 53 is provided between the third port 13 and the fourth port 14.

[0026] The second pipe 20 has a plurality of fifth ports 21, sixth ports 22, seventh ports 23 and eighth ports 24 arranged sequentially along its extension direction; a fourth switching device is arranged between every two adjacent fifth ports 21; a fifth switching device 55 is arranged between the last fifth port 21 and the sixth port 22, and a sixth switching device 56 is arranged between the sixth port 22 and the seventh port 23.

[0027] The multiple heat exchange tubes have multiple first heat exchange tubes 30 and second heat exchange tubes 40; each first heat exchange tube is disposed between a second port 12 and a fifth port 21; the second heat exchange tube is disposed between a third port 13 and a seventh port 23.

[0028] The fourth port 14 is connected to the seventh port 23; the sixth port 22 is connected to the end of the second heat exchange tube furthest from the seventh port 23; a seventh on / off device 57 is installed on the pipeline between the sixth port 22 and the corresponding end of the second heat exchange tube; an eighth on / off device 58 is installed on the pipeline between the third port 13 and the corresponding end of the second heat exchange tube; the eighth port 24 is connected to the indoor heat exchanger through a throttling device.

[0029] The defrosting control method for air conditioners may include the following steps: Step S100: Determine whether outdoor heat exchanger 1 needs defrosting; if so, proceed to step S200. In step S200, the refrigerant first enters the outdoor heat exchanger 1 and then the indoor heat exchanger, and the first on / off device, the second on / off device 52, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, and the eighth on / off device 58 are all in the conducting state, while the third on / off device 53 and the seventh on / off device 57 are in the off state; so that multiple first heat exchange tubes and second heat exchange tubes are in a parallel state, thereby allowing the refrigerant to directly enter each heat exchange tube through the first port.

[0030] Specifically, the air conditioner also includes a throttling device, and the eighth opening of the outdoor heat exchanger 1 is connected to the indoor heat exchanger through the throttling device. During the heating operation of the air conditioner, the refrigerant flow direction is: compressor → four-way valve → indoor heat exchanger (condenser) → throttling device → outdoor heat exchanger 1 (evaporator) → four-way valve → compressor. At this time, the on / off device can be controlled to a flow path state suitable for efficient heating; for example, the refrigerant can be concentrated to flow through a portion of the heat exchange tubes to improve flow rate and efficiency.

[0031] During the heating process of the air conditioner, step S100 is executed. In step S100, the judgment criteria may include the difference between the outdoor ambient temperature and the pipe temperature of the outdoor heat exchanger 1, the degree of heating performance degradation, or the surface temperature of the outdoor heat exchanger 1, etc.

[0032] In step S200, when it is determined that the outdoor heat exchanger 1 needs defrosting, the air conditioner stops heating operation, switches the four-way valve, and changes the overall flow direction of the refrigerant in the system, so that the high-temperature, high-pressure gaseous refrigerant discharged from the compressor flows to the outdoor heat exchanger 1 first, entering defrosting mode. Simultaneously, by connecting the first, second, fourth, fifth, sixth, and eighth switching devices and disconnecting the third and seventh switching devices, the internal flow path of the outdoor heat exchanger 1 is reconstructed, so that multiple first and second heat exchange tubes are connected in parallel. The specific defrosting flow path and process are as follows: The high-temperature, high-pressure refrigerant discharged from the compressor is guided through the four-way valve to the first port 11 of the first pipe 10. The refrigerant will directly flow from the first port 11 to each first and second heat exchange tube, allowing the high-temperature refrigerant to flow simultaneously and comprehensively through the entire outdoor heat exchanger 1, thereby achieving comprehensive and synchronous defrosting of the entire outdoor heat exchanger 1.

[0033] This embodiment, based on a variable flow outdoor heat exchanger 1, allows multiple heat exchange tubes of the outdoor heat exchanger 1 to form parallel flow paths during defrosting. This ensures that the defrosting heat evenly and quickly covers the entire surface of the heat exchanger, significantly reducing the defrosting time. This not only reduces energy waste but, more importantly, minimizes the time the indoor unit stops heating due to defrosting, effectively avoiding significant fluctuations in indoor temperature and significantly improving the user's heating comfort experience during harsh winters.

[0034] In some optional embodiments of the present invention, while performing step S200, the defrosting control method of the air conditioner may further include: turning off the indoor fan.

[0035] Turning off the indoor fan during the defrosting process can reduce the impact of defrosting on the indoor temperature.

[0036] Furthermore, while performing step S200, the defrosting control method of the air conditioner may also include: controlling the throttling device to perform a preset opening degree.

[0037] Preferably, the preset opening degree is the maximum opening degree. The throttling device is an expansion valve.

[0038] During the defrosting process, adjusting the throttling device to a larger opening will facilitate faster defrosting.

[0039] In some embodiments of the present invention, a plurality of first heat exchange tubes and second heat exchange tubes are arranged sequentially along the length or width direction of the outdoor heat exchanger.

[0040] like Figure 2 As shown, the defrosting control method also includes the following steps: Step S300: Obtain the number of defrosted areas in each of the multiple heat exchange tubes. In step S400, when the number is greater than or equal to the preset number, the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57 and the eighth on / off device 58 are controlled so that no refrigerant passes through the heat exchange tubes corresponding to the areas that have been partially or completely defrosted.

[0041] Specifically, the preset number can be set according to the total number of heat exchange tubes. For example, the preset number can be half or more of the total number of heat exchange tubes.

[0042] In this embodiment, during the defrosting process, the air conditioner monitors the defrosting status of each area in real time. When the number of areas that have completed defrosting is greater than or equal to a preset number, the air conditioner readjusts the state of each on / off device to cut off or reduce the flow of refrigerant to the defrosted areas, thus avoiding heat waste. Concentrating the defrosting heat supply to the areas that have not yet defrosted further improves defrosting efficiency, saves energy, and prevents the defrosted areas from being overheated, which is beneficial for quickly resuming the heating mode after defrosting is completed.

[0043] In some embodiments of the present invention, the preset number is the number of heat exchange tubes minus two. The number of second ports 12 is four, the number of fifth ports 21 is four, and the number of first heat exchange tubes is four. Multiple first on / off devices are a first control valve 511, a second control valve 512, and a third control valve 513 arranged sequentially along the extension direction of the first tube 10. Multiple fourth on / off devices are a fourth control valve 541, a fifth control valve 542, and a sixth control valve 543 arranged sequentially along the extension direction of the first tube 10.

[0044] In some embodiments of the present invention, step S400, when the number is greater than or equal to a preset number, controls the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57, and the eighth on / off device 58 so that no refrigerant passes through the heat exchange tubes corresponding to areas that have been partially or completely defrosted, may include: controlling the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57, and the eighth on / off device 58 so that the refrigerant only passes through the heat exchange tubes corresponding to areas that have not been defrosted.

[0045] This embodiment is a preferred implementation of the previous embodiment. By precisely controlling the on / off device, this embodiment ensures that the refrigerant flows only through the heat exchange tubes corresponding to areas that have not yet defrosted, completely bypassing the heat exchange tubes corresponding to areas that have already defrosted. This eliminates areas still covered in frost most quickly, maximizing defrosting efficiency.

[0046] For example, such as Figure 6 As shown, when the areas corresponding to the top two first heat exchange tubes have not been defrosted, while the areas corresponding to the remaining heat exchange tubes have been defrosted, the first control valve 511, the fourth control valve 541, the fifth control valve 542, the sixth control valve 543, the fifth control device 55, and the sixth control device 56 are all in the conducting state, and the second control valve 512, the third control valve 513, the second control device 52, the third control device 53, the seventh control device 57, and the eighth control device 58 are all in the disconnected state, so that the refrigerant only passes through the top two first heat exchange tubes for precise defrosting.

[0047] In some embodiments of the present invention, after step S400, the defrosting control method further includes the following step: when the defrosting mode exit condition is met, exiting the defrosting mode and executing the heating mode. This exit condition can be that defrosting has been completed in the respective areas corresponding to each heat exchanger tube.

[0048] In some embodiments of the present invention, a temperature detection device is provided on each of the areas corresponding to the multiple heat exchange tubes, so as to determine whether defrosting has been completed on each of the areas corresponding to the heat exchange tubes, at least based on the detected temperature.

[0049] In some embodiments of the present invention, a temperature detection device is provided on the outlet pipe corresponding to each of the multiple heat exchange tubes, so as to determine whether defrosting has been completed in the area corresponding to each heat exchange tube, at least based on the detected temperature.

[0050] In the two embodiments described above, temperature sensors are installed on the surface of the heat exchange tube or its outlet pipe to directly or indirectly detect the temperature of the area corresponding to the heat exchange tube. When the temperature rises to a set value and remains at that value for a set duration, it can be determined that the frost layer in that area has completely melted. These two embodiments provide a direct and reliable technical means to determine whether defrosting is complete. This forms the basis for achieving a precise defrosting control strategy.

[0051] Furthermore, the set temperature is ≥5℃ and the set duration is ≥5 seconds. For example, when the heat exchange tube meets the condition of exceeding 7 degrees for 30 seconds or exceeding 10 degrees for 10 seconds, it can be determined that the area corresponding to the heat exchange tube has completed defrosting.

[0052] like Figure 3 As shown, in some embodiments of the present invention, the defrosting control method for an air conditioner may further include the following steps: Step S500: When defrosting is not required for the outdoor heat exchanger 1, obtain the degree of frost on the outdoor heat exchanger 1. In step S600, based on the degree of frost, control the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57 and the eighth on / off device 58 so that the number of refrigerants that directly enter the heat exchange tube through the eighth port 24 corresponds to the degree of frost.

[0053] Specifically, after step S100, if the outdoor heat exchanger 1 does not require defrosting, the air conditioner continues to operate in heating mode and proceeds to step S500. In step S500: during the operation of the air conditioner in heating mode, the degree of frost on the outdoor heat exchanger 1 is acquired in real-time or periodically. This degree of frost can be the overall temperature of the heat exchanger surface, which can be characterized by the average surface temperature of multiple heat exchange tubes; alternatively, the degree of frost can also be the surface temperature of each heat exchanger, i.e., a collection of multiple temperatures; the degree of frost can be indirectly characterized by the pressure difference between the air inlet and outlet of the outdoor heat exchanger, with an increased pressure difference indicating increased wind resistance due to frost; or, the degree of frost can be estimated by the ratio of the current operating current of the outdoor fan to the reference frost-free current.

[0054] In step S600: In normal heating mode, the flow path of the outdoor heat exchanger 1 is dynamically adjusted according to the degree of frost, so that the number of refrigerant tubes directly entering the heat exchange tubes through the eighth port 24 corresponds to the degree of frost. That is, the optimal refrigerant flow path is determined according to the degree of frost, and the refrigerant flow path is made to correspond to the optimal refrigerant flow path by controlling each on / off device door, so as to balance the heating effect of the air conditioner and the defrosting prevention effect.

[0055] For example, when there are 4 heat exchange tubes and 3 of them have refrigerant directly entering the heat exchange tubes through the eighth port 24, the three-way flow can be achieved in at least a few ways: Firstly, the second control valve 512, the third control valve 513, the fourth control valve 541, the sixth control valve 543, the second on / off device 52, the fifth on / off device 55, the sixth on / off device 56, and the eighth on / off device 58 are all in the conducting state, while the first control valve 511, the fifth control valve 542, the third on / off device 53, and the seventh on / off device 57 are all in the off state. In the second method, the first control valve 511, the third control valve 513, the fourth control valve 541, the fifth control valve 542, the sixth control valve 543, the second on / off device 52, the fifth on / off device 55, the third on / off device 53, and the seventh on / off device 57 are all in the conducting state, while the second control valve 512, the sixth on / off device 56, and the eighth on / off device 58 are all in the off state. In this case, the refrigerant flow path allows the refrigerant to directly enter the three heat exchange tubes through the eighth port 24, and the refrigerant flows through all the heat exchange tubes.

[0056] This embodiment extends the advantages of variable flow path technology from the defrosting stage to the entire heating process. It achieves "on-demand defrosting" and "preventive defrosting," intervening in the early stages of frost formation to effectively delay the onset of severe frost, keeping the machine operating in its high-efficiency range and improving overall heating efficiency and stability.

[0057] like Figure 4 As shown, in some embodiments of the present invention, step S600, controlling the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57, and the eighth on / off device 58 according to the degree of frost, includes: In step S610, when the degree of frost increases, control the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57 and the eighth on / off device 58 so that the number of refrigerants that directly enter the heat exchange tubes through the eighth port 24 increases.

[0058] In step S620, when the degree of frost decreases, control the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57 and the eighth on / off device 58 so that the number of refrigerants that directly enter the heat exchange tube through the eighth port 24 is reduced.

[0059] For example, the number of refrigerants that enter the outdoor heat exchanger 1 through the eighth port 24 and directly enter the first heat exchange tube is recorded as the first number.

[0060] When the frosting level reaches the first preset frosting level, control the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57 and the eighth on / off device 58 so that the number of refrigerant directly entering the heat exchange tube through the eighth port 24 is the second number, and the second number is greater than the first number.

[0061] When the frosting level reaches the second preset frosting level, control the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57, and the eighth on / off device 58 so that the number of refrigerant directly entering the heat exchange tube through the eighth port 24 is the third number, which is greater than the second number; the second preset frosting level is greater than the first preset frosting level.

[0062] This embodiment incorporates a bidirectional adjustment mechanism, enabling more precise and dynamic on-demand matching of the outdoor heat exchanger 1. Specifically, in the air conditioner's heating mode, when frost worsens, the number of refrigerants directly entering the heat exchange tubes through the eighth port 24 is increased to increase the refrigerant flow rate within the outdoor heat exchanger 1. This results in a corresponding increase in the refrigerant outlet temperature of the indoor heat exchanger, allowing the outdoor heat exchanger 1 to better perform its pre-defrosting function and delay the triggering of the defrosting mode. Conversely, when frost lessens, the number of refrigerants directly entering the heat exchange tubes through the eighth port 24 is reduced to decrease the refrigerant flow rate within the outdoor heat exchanger 1. This optimizes the system's operating efficiency under light frost or no-frost conditions, achieving energy-saving operation.

[0063] In some embodiments of the present invention, step S600, which controls the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57, and the eighth on / off device 58 according to the degree of frosting, may further include: In step S630, after the frosting level reaches a preset frosting level, the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57, and the eighth on / off device 58 are controlled to gradually increase the number of refrigerants that directly enter the heat exchange tubes through the eighth port 24. Specifically, the number gradually increases according to a preset time interval.

[0064] This embodiment achieves a smooth transition in the air conditioner's operating state by employing a gradual adjustment strategy. Specifically, after the frosting level reaches the preset level, the number of refrigerant tubes directly entering through port 24 is gradually increased at preset time intervals. This effectively avoids system pressure and flow fluctuations caused by sudden changes in the refrigerant flow path, gradually increasing the pre-defrosting effect on the heat exchanger while continuously maintaining the system's heating performance.

[0065] like Figure 5 As shown, in some embodiments of the present invention, when the outdoor heat exchanger 1 does not require defrosting, the defrosting control method of the air conditioner may further include the following steps: Step S700: Obtain the amount of frost on each corresponding area of ​​the heat exchange tube; In step S800, when controlling the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57 and the eighth on / off device 58 according to the degree of frost, the refrigerant is also allowed to directly enter the heat exchange tubes, including the heat exchange tubes corresponding to the area with the largest amount of frost, through the eighth port 24.

[0066] In this embodiment, while adjusting the refrigerant flow path of the outdoor heat exchanger 1 according to the overall frosting level, priority is given to ensuring that the refrigerant flows through the area with the largest amount of frosting, thereby specifically enhancing the heat exchange effect in that area. This control strategy enables early intervention and focused treatment of key frosting areas, effectively preventing excessive accumulation of local frost layers, and thus further delaying the triggering of the defrosting mode while maintaining the overall heating stability of the system.

[0067] In some embodiments of the present invention, the defrosting control method for an air conditioner may further include the following steps: Step S900: Before the outdoor heat exchanger 1 needs to be defrosted, the amount of frost on each corresponding area of ​​the heat exchange tube is obtained. Step S1000: Control the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57 and the eighth on / off device 58 so that the refrigerant can directly enter the heat exchange tubes, including the heat exchange tubes corresponding to the area with the largest amount of frost, through the eighth port 24.

[0068] Specifically, the preset time can be from 30s to 300s, preferably 60s.

[0069] In this embodiment, before determining that defrosting mode needs to be entered, the frost distribution in each area is obtained in advance, and the flow path is controlled to allow the relatively higher temperature refrigerant to flow preferentially to the areas with the most severe frost. This pre-adjustment method can alleviate the accumulation of frost in key areas before the formal defrosting begins, effectively reducing the initial load of subsequent formal defrosting, creating favorable conditions for shortening the overall defrosting time, and improving the overall efficiency of the defrosting process.

[0070] In a preferred embodiment of the present invention, the defrosting control method for an air conditioner may include: Step S1: Determine whether outdoor heat exchanger 1 needs defrosting; if yes, proceed to S2; otherwise, proceed to S6.

[0071] Step S2: Control the air conditioner to enter defrost mode: Turn off the indoor fan and adjust the throttling device to the maximum opening; allow the refrigerant to enter the outdoor heat exchanger 1 first and then the indoor heat exchanger, and control the first on / off device, the second on / off device 52, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, and the eighth on / off device 58 to be in the conducting state, and control the third on / off device 53 and the seventh on / off device 57 to be in the off state, so that multiple first heat exchange tubes and second heat exchange tubes are in parallel, thereby allowing the refrigerant to directly enter each heat exchange tube through the first port.

[0072] Step S3: In defrosting mode, obtain the number of areas that have been defrosted in the respective regions of multiple heat exchange tubes.

[0073] Step S4: When the number of defrosted areas is greater than or equal to a preset number, control the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57 and the eighth on / off device 58 so that no refrigerant passes through the heat exchange tubes corresponding to all defrosted areas.

[0074] Step S5: When defrosting has been completed in the area corresponding to each heat exchange tube, control the air conditioner to exit the defrosting mode and enter the heating mode. Step S6: Obtain the degree of frost on the outdoor heat exchanger 1; Step S7: Obtain the amount of frost on each corresponding area of ​​the heat exchange tube; Step S8: Based on the degree of frost, control the first on / off device, the second on / off device 52, the third on / off device 53, the fourth on / off device, the fifth on / off device 55, the sixth on / off device 56, the seventh on / off device 57, and the eighth on / off device 58, so that the number of heat exchange tubes through the eighth port 24 corresponds to the degree of frost, and also ensure that the heat exchange tubes through the eighth port 24 include the heat exchange tubes corresponding to the area with the largest amount of frost.

[0075] This embodiment achieves a dual improvement in defrosting efficiency and heating stability by integrating flow path control for both defrosting and heating modes. During defrosting, a fully parallel flow path is used for rapid defrosting, and the flow path in defrosted areas is dynamically cut off to concentrate heat. During heating, the flow path is precisely allocated according to the degree and distribution of frost. This method ensures both rapid and energy-efficient defrosting and effectively delays frost formation through preventative control, significantly improving user experience and system energy efficiency.

[0076] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A defrosting control method for an air conditioner, characterized in that, The air conditioner includes an outdoor heat exchanger and an indoor heat exchanger. The outdoor heat exchanger includes: The first tube has a first port, a plurality of second ports, a third port and a fourth port arranged sequentially along its extension direction; a first switching device is arranged between every two adjacent second ports, a second switching device is arranged between the last second port and the third port, and a third switching device is arranged between the third port and the fourth port. The second tube has a plurality of fifth, sixth, seventh and eighth ports arranged sequentially along its extension direction; a fourth switching device is arranged between every two adjacent fifth ports; a fifth switching device is arranged between the last fifth port and the sixth port, and a sixth switching device is arranged between the sixth port and the seventh port. Multiple heat exchange tubes, including multiple first heat exchange tubes and multiple second heat exchange tubes; each first heat exchange tube is disposed between a second port and a fifth port; the second heat exchange tube is disposed between a third port and a seventh port; The fourth port is connected to the seventh port; the sixth port is connected to the end of the second heat exchange tube furthest from the seventh port; a seventh on / off device is provided on the pipeline between the sixth port and the corresponding end of the second heat exchange tube; an eighth on / off device is provided on the pipeline between the third port and the corresponding end of the second heat exchange tube; the eighth port is connected to the indoor heat exchanger through a throttling device. The defrosting control method includes: Determine whether the outdoor heat exchanger needs defrosting; If so, the refrigerant enters the outdoor heat exchanger first and then the indoor heat exchanger, and the first, second, fourth, fifth, sixth, and eighth on / off devices are all in the conducting state, while the third and seventh on / off devices are in the off state.

2. The defrosting control method for an air conditioner according to claim 1, characterized in that, Multiple first heat exchange tubes and second heat exchange tubes are arranged sequentially along the length or width of the outdoor heat exchanger; The defrosting control method further includes: Obtain the number of defrosted areas in the respective regions of each of the multiple heat exchange tubes; When the number is greater than or equal to a preset number, the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device are controlled so that no refrigerant passes through the heat exchange tubes corresponding to areas that have been partially or completely defrosted.

3. The defrosting control method for an air conditioner according to claim 2, characterized in that, When the number is greater than or equal to a preset number, controlling the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device, so that no refrigerant passes through the heat exchange tubes corresponding to areas that have been partially or completely defrosted, includes: Control the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device so that the refrigerant only passes through the heat exchange tube corresponding to the area that has not been defrosted.

4. The defrosting control method for an air conditioner according to claim 3, characterized in that, The preset number is the number of heat exchange tubes minus two; The number of the second port is four, the number of the fifth port is four; the number of the first heat exchange tubes is four; The plurality of first switching devices are a first control valve, a second control valve, and a third control valve arranged sequentially along the extension direction of the first pipe; The plurality of fourth on / off devices are respectively a fourth control valve, a fifth control valve, and a sixth control valve arranged sequentially along the extension direction of the first pipe.

5. The defrosting control method for an air conditioner according to claim 1, characterized in that, Each of the heat exchange tubes is equipped with a temperature detection device in its respective area to determine whether defrosting has been completed in its respective area based at least on the detected temperature. or Each of the heat exchange tubes is equipped with a temperature detection device on its corresponding outlet pipe to determine whether defrosting has been completed in the area corresponding to each heat exchange tube, based at least on the detected temperature.

6. The defrosting control method for an air conditioner according to claim 1, characterized in that, Also includes: When the outdoor heat exchanger does not require defrosting, the degree of frost formation on the outdoor heat exchanger is obtained; Based on the degree of frost formation, the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device are controlled so that the number of refrigerants that directly enter the heat exchange tube through the eighth port corresponds to the degree of frost formation.

7. The defrosting control method for an air conditioner according to claim 6, characterized in that, The step of controlling the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device according to the degree of frost includes: When the degree of frost increases, control the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device to increase the number of refrigerants that directly enter the heat exchange tube through the eighth port; When the degree of frost decreases, control the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device to reduce the number of refrigerants that directly enter the heat exchange tube through the eighth port.

8. The defrosting control method for an air conditioner according to claim 6, characterized in that, The step of controlling the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device according to the degree of frost includes: After the frosting reaches the preset frosting level, the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device are controlled to gradually increase the number of refrigerants that directly enter the heat exchange tube through the eighth port.

9. The defrosting control method for an air conditioner according to claim 6, characterized in that, When the outdoor heat exchanger does not require defrosting, it also includes: Obtain the amount of frost on each corresponding area of ​​the heat exchange tube; When controlling the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device according to the degree of frost, the refrigerant is also allowed to directly enter the heat exchange tube through the eighth port, including the heat exchange tube corresponding to the area with the largest amount of frost.

10. The defrosting control method for an air conditioner according to claim 1, characterized in that, Also includes: Before the outdoor heat exchanger needs to be defrosted, the amount of frost on each area of ​​the heat exchange tube is obtained by pre-setting the time. Control the first on / off device, the second on / off device, the third on / off device, the fourth on / off device, the fifth on / off device, the sixth on / off device, the seventh on / off device, and the eighth on / off device so that the refrigerant directly enters the heat exchange tube, including the heat exchange tube corresponding to the area with the largest amount of frost, through the eighth port.

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