Defrosting method, system, computer readable storage medium and air conditioner

Abstract

This invention relates to the field of air conditioning technology, and discloses a defrosting method, system, computer-readable storage medium, and air conditioner. The indoor heat exchanger includes an air inlet side heat exchange module and an air outlet side heat exchange module arranged sequentially along the air inlet and outlet directions of the indoor unit. The defrosting method includes the following steps: controlling the air conditioner to start the heating mode, and acquiring the heating operation time t and the temperature T of the outdoor heat exchanger. 外 When the heating operation time t and the outdoor heat exchanger temperature T are determined... 外 When the set defrosting start conditions are met, defrosting begins; and the temperature T of the outdoor heat exchanger is determined. 外 If the temperature exceeds the first set temperature threshold T1, the system controls the inlet-side heat exchange module to close and the outlet-side heat exchange module to open; otherwise, it controls the inlet-side heat exchange module to open and the outlet-side heat exchange module to close, and controls the four-way valve to switch the refrigerant flow direction. This invention improves the defrosting rate without affecting indoor heating comfort, achieving a balance between defrosting efficiency and heating comfort.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and more specifically to defrosting methods, systems, computer-readable storage media, and air conditioners. Background Technology

[0002] During the heating operation of an air conditioner, the refrigerant exchanges heat with the outdoor air through the outdoor heat exchanger, absorbing heat from the outdoor air and evaporating. The compressor compresses the low-temperature, low-pressure refrigerant into high-temperature, high-pressure refrigerant vapor, which enters the indoor heat exchanger to release heat. The heat released through the indoor heat exchanger heats the indoor air, allowing people to enjoy a more comfortable environment.

[0003] However, because the outdoor heat exchanger absorbs heat from the outdoor air, the temperature around it is low, causing water vapor in the air to condense and frost onto its surface. As the air conditioner runs for longer periods, the frost thickens, increasing the thermal resistance between the heat exchanger surface and the air, and increasing airflow resistance. This reduces the airflow through the heat exchanger, significantly lowering heat exchange efficiency and consequently decreasing the amount of heat exchanged between the outdoor environment and the refrigerant. Consequently, the air conditioner's heating capacity decreases, affecting user comfort. Therefore, when the air conditioner is in heating mode, timely and effective defrosting of the outdoor heat exchanger is necessary.

[0004] In existing technology, air conditioners typically use a reverse cycle defrosting method, which involves switching the four-way valve from heating mode to cooling mode and using the heat from the compressor and refrigerant to defrost the outdoor unit. However, this reverse cycle defrosting method requires the absorption of a large amount of heat from the room during defrosting, resulting in a decrease in indoor temperature. This is especially noticeable on the side near the air outlet of the air conditioner, which affects the comfort of the air conditioner's heating function. Summary of the Invention

[0005] In view of this, the present invention provides a defrosting method, system, computer-readable storage medium, and air conditioner to solve the problem in the prior art that the indoor unit of an air conditioner will transfer cold energy to the indoor unit during the defrosting process, affecting heating comfort.

[0006] In a first aspect, the present invention provides a defrosting method for an air conditioner, wherein the indoor heat exchanger of the air conditioner includes an air inlet side heat exchange module and an air outlet side heat exchange module arranged sequentially along the air inlet and outlet directions of the indoor unit.

[0007] The defrosting method includes the following steps:

[0008] Control the air conditioner to start the heating mode, and obtain the heating operation time t and the outdoor heat exchanger temperature T. 外 ;

[0009] When the heating operation time t and the outdoor heat exchanger temperature T are determined... 外 When the set defrosting start conditions are met, defrosting will begin;

[0010] And further determine the temperature T of the outdoor heat exchanger. 外 Is it greater than the first set temperature threshold T1?

[0011] If yes, then control the inlet side heat exchange module to close and the outlet side heat exchange module to open; if no, control the inlet side heat exchange module to open and the outlet side heat exchange module to close, and control the four-way valve of the air conditioner to switch the refrigerant flow direction.

[0012] Beneficial effects: When the heating operation time t and the outdoor heat exchanger temperature T are determined... 外 When the set defrosting start conditions are met, defrosting is controlled according to various frosting conditions of the outdoor condenser. Specifically, when the temperature T of the outdoor heat exchanger is determined... 外 When the temperature exceeds the first set temperature threshold T1, it can be inferred that the frost is not severe. At this time, while operating in normal heating mode, the heat exchange module on the air inlet side is turned off and the heat exchange module on the air outlet side is turned on, thereby reducing the actual heat exchange area of ​​the indoor heat exchanger and reducing the heat released by the indoor heat exchanger. This allows most of the heat in the circulating refrigerant to be directly transferred to the outdoor heat exchanger for heat release, ensuring both heat exchange efficiency and ensuring that the indoor heat exchanger can continuously supply heat to the indoor side when there is little frost, thus ensuring the continuity of heating and improving the thermal comfort experience.

[0013] Furthermore, when the temperature T of the outdoor heat exchanger is determined... 外 When the temperature is less than or equal to the first set temperature threshold T1, it can be inferred that the frost is severe. At this time, the inlet-side heat exchange module is turned on and the outlet-side heat exchange module is turned off. The four-way valve is also controlled to switch the refrigerant flow direction. After the four-way valve switches, the high-temperature refrigerant directly enters the outdoor heat exchanger for defrosting. Moreover, when the refrigerant circulates indoors, it only passes through the inlet-side heat exchange module and not the outlet-side heat exchange module. This ensures that the indoor evaporator does not transfer cold energy into the room when there is a lot of frost. While ensuring the defrosting effect, this method improves the problem of a sudden drop in indoor temperature during the defrosting process, especially the problem of a noticeable cold feeling on the side of the air conditioner's air outlet, thereby improving the user experience. The defrosting method provided in this embodiment ensures both the defrosting efficiency of the outdoor heat exchanger and the heating comfort of the indoor side. It improves the defrosting rate without affecting the indoor heating comfort, solving the problem that existing defrosting methods cannot balance defrosting efficiency and heating comfort.

[0014] In one alternative implementation, when the temperature T of the outdoor heat exchanger is determined... 外 If the temperature exceeds the first set temperature threshold T1, the following steps will be performed:

[0015] Determine the temperature T of the outdoor heat exchanger 外 Whether it is greater than or equal to the second set temperature threshold T2, wherein the first set temperature threshold T1 < the second set temperature threshold T2 < 0℃;

[0016] If so, it enters the first defrosting mode, controls the inlet side heat exchange module to close and the outlet side heat exchange module to open, and at the same time controls the indoor fan speed to decrease.

[0017] If not, it enters the second defrosting mode, controlling the inlet-side heat exchange module to close and the outlet-side heat exchange module to open, while simultaneously controlling the indoor fan to close.

[0018] In one alternative implementation, upon entering the second defrost mode, the following steps are also performed:

[0019] The bypass defrosting branch between the compressor outlet and the outdoor heat exchanger is opened, allowing some high-temperature refrigerant to directly enter the outdoor heat exchanger for defrosting via the bypass defrosting branch.

[0020] In one alternative implementation, the following steps are performed while controlling the conduction of the bypass defrosting branch:

[0021] Obtain the temperature T of the heat exchange module on the air outlet side. 内 And indoor temperature T0;

[0022] By adjusting the opening of the throttle valve on the bypass defrosting branch, the temperature T of the heat exchange module on the outlet side is adjusted. 内 It is greater than the indoor temperature T0, and the difference between it and the indoor temperature T0 is greater than the set temperature difference △T.

[0023] In one alternative implementation, the temperature difference ΔT is set to be between 4°C and 6°C.

[0024] In one optional implementation, the defrosting start conditions include normal start conditions, which include:

[0025] The heating operation time t is greater than or equal to the set time t1, and the temperature T of the outdoor heat exchanger is... 外 Less than or equal to the set defrost start temperature, wherein the second set temperature threshold T2 < set defrost start temperature ≤ 0℃;

[0026] When the heating operation time t and the outdoor heat exchanger temperature T are determined... 外 If the normal startup conditions are met, the subsequent determination of the outdoor heat exchanger temperature T will proceed normally. 外 The step of determining whether the temperature exceeds the first set temperature threshold T1.

[0027] In an optional implementation, the defrosting start condition further includes an emergency start condition, which includes:

[0028] The heating operation time t is less than the set time t1, but the temperature T of the outdoor heat exchanger 外 Less than or equal to the third set temperature threshold T3, and the third set temperature threshold T3 < the first set temperature threshold T1;

[0029] When the heating operation time t and the outdoor heat exchanger temperature T are determined... 外 When the aforementioned emergency start conditions are met, the system will directly enter the third defrosting mode.

[0030] The third defrosting mode includes: controlling the inlet heat exchange module to be turned on, the outlet heat exchange module to be turned off, and controlling the four-way valve to switch the refrigerant flow direction.

[0031] In one optional implementation, during the defrosting process, when it is determined that the air conditioner meets the preset defrosting exit conditions, the defrosting mode is exited and the normal heating mode is restored.

[0032] Among them, the defrosting exit conditions include the outdoor heat exchanger temperature T. 外 The defrost exit temperature is greater than or equal to the set defrost exit temperature, or the defrost run time is greater than the set duration.

[0033] In a second aspect, the present invention also provides a defrosting system, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the defrosting method of any of the above embodiments.

[0034] Thirdly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the defrosting method of any of the above embodiments.

[0035] Fourthly, the present invention also provides an air conditioner that performs defrosting using any of the defrosting methods described above. The air conditioner includes an indoor unit and an outdoor unit, the indoor unit comprising:

[0036] The housing has an air inlet and an air outlet.

[0037] The indoor heat exchanger includes an air inlet side heat exchange module and an air outlet side heat exchange module arranged sequentially along the air inlet and outlet directions of the indoor unit.

[0038] The air inlet heat exchange module is located near the air inlet, and the air outlet heat exchange module is located near the air outlet.

[0039] In one alternative embodiment, the outdoor unit includes a compressor, a four-way valve, a first throttle valve, and an outdoor heat exchanger; the air conditioner also includes:

[0040] The main circuit is formed by connecting the compressor, four-way valve, indoor heat exchanger, first throttle valve and outdoor heat exchanger in series. The main circuit includes a first pipeline connecting the outlet end of the four-way valve and the inlet end of the indoor heat exchanger, and a second pipeline connecting the outlet end of the indoor heat exchanger and the inlet end of the outdoor heat exchanger.

[0041] The first branch and the second branch are connected in parallel on the main circuit. The heat exchange module on the air inlet side and the heat exchange module on the air outlet side are connected in parallel on the main circuit. The outlet end of the first pipeline branches to form the first branch and the second branch. The first branch is connected between the four-way valve and the inlet end of the heat exchange module on the air inlet side, and the second branch is connected between the four-way valve and the inlet end of the heat exchange module on the air outlet side.

[0042] A first control valve and a second control valve are provided. The first control valve is located on the first branch and is suitable for controlling the on / off state of the first branch. The second control valve is located on the second branch and is suitable for controlling the on / off state of the second branch.

[0043] In one alternative implementation, the air conditioner further includes:

[0044] A bypass defrosting branch is connected between the first and second pipelines, and the bypass defrosting branch is set in parallel with the indoor heat exchanger;

[0045] The second throttle valve is installed on the bypass defrosting branch and is suitable for controlling the on / off state and flow rate of the bypass defrosting branch. Attached Figure Description

[0046] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of the refrigerant flow direction when the air conditioner is in heating mode in an embodiment of the present invention (shown by the dotted lines and arrows in the figure);

[0048] Figure 2 This is a schematic diagram of the refrigerant flow direction when the air conditioner is in the first defrosting mode in an embodiment of the present invention (shown by the dotted lines and arrows in the figure);

[0049] Figure 3 This is a schematic diagram of the refrigerant flow direction when the air conditioner is in the second defrosting mode in an embodiment of the present invention (shown by the dotted lines and arrows in the figure);

[0050] Figure 4This is a schematic diagram of the refrigerant flow direction when the air conditioner is in the third defrosting mode in an embodiment of the present invention (shown by the dotted lines and arrows in the figure);

[0051] Figure 5 This is a flowchart illustrating the first embodiment of the defrosting method for an air conditioner in this invention.

[0052] Figure 6 This is a flowchart illustrating the second embodiment of the defrosting method for an air conditioner in this invention.

[0053] Figure 7 This is a flowchart illustrating the third embodiment of the defrosting method for an air conditioner in this invention.

[0054] Explanation of reference numerals in the attached figures:

[0055] 10. Outdoor unit; 11. Outdoor heat exchanger; 12. Four-way valve; 13. Compressor; 14. First throttle valve; 15. Second throttle valve;

[0056] 20. Indoor unit; 21. Indoor heat exchanger; 211. Inlet air side heat exchange module; 212. Outlet air side heat exchange module; 22. First control valve; 23. Second control valve;

[0057] 101. Main circuit; 1011. First branch circuit; 1012. Second branch circuit; 102. Bypass defrosting branch circuit. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0060] Conventional air conditioners generally use a reverse-cycle defrosting method, which involves switching the four-way valve from heating mode to cooling mode to defrost the outdoor unit. During defrosting, the refrigerant in the indoor heat exchanger is in a cold state and exchanges heat with the warm indoor air, causing a drop in indoor temperature. This is especially noticeable near the air outlet, affecting the comfort of the air conditioner during heating. Because a large amount of heat needs to be absorbed from the indoor air during defrosting, the significant temperature drop severely impacts the user's thermal comfort experience.

[0061] Therefore, to solve the above problems, those skilled in the art have developed a hot gas defrosting method. During air conditioner defrosting, the system continues to operate in heating mode, with the electronic expansion valve fully open. This ensures that the refrigerant enters the condenser at a relatively high temperature for heat exchange and defrosting. Because the high-temperature refrigerant flows through the indoor unit's evaporator first during defrosting, the evaporator maintains a consistently high temperature. After defrosting, the electronic expansion valve resets, restoring normal heating operation. However, since evaporator heat exchange consumes a lot of heat, this method is inefficient and ineffective when the outdoor unit is heavily frosted. Switching to conventional reverse-cycle defrosting would compromise heating comfort.

[0062] In view of this, this embodiment is proposed to solve the problem that when the outdoor unit is severely frosted, the hot air defrosting method has low defrosting efficiency and poor defrosting effect, while switching to conventional reverse circulation defrosting will affect heating comfort. It is impossible to balance defrosting efficiency and heating comfort.

[0063] The following is combined with Figures 1 to 7 The following describes embodiments of the present invention.

[0064] According to an embodiment of the present invention, in one aspect, the present invention provides a defrosting method for an air conditioner, wherein the indoor heat exchanger 21 of the air conditioner includes an air inlet side heat exchange module 211 and an air outlet side heat exchange module 212 arranged sequentially along the air inlet and outlet directions of the indoor unit 20, combined with Figures 1 to 5 As shown, the defrosting method includes the following steps:

[0065] Step S101: Control the air conditioner to start the heating mode, and obtain the heating operation time t and the temperature T of the outdoor heat exchanger 11. 外 ;

[0066] Step S102: When the heating operation time t and the temperature T of the outdoor heat exchanger 11 are determined... 外 When the set defrosting start conditions are met, defrosting will begin;

[0067] Step S103: Further determine the temperature T of the outdoor heat exchanger 11. 外 Is the temperature greater than the first set temperature threshold T1? If yes, proceed to step S104; if no, proceed to step S105.

[0068] Step S104: Then control the inlet side heat exchange module 211 to close and the outlet side heat exchange module 212 to open;

[0069] Step S105: Then control the air inlet side heat exchange module 211 to be turned on and the air outlet side heat exchange module 212 to be turned off, and control the four-way valve 12 of the air conditioner to switch the refrigerant flow direction.

[0070] In the above embodiment, when the heating operation time t and the temperature T of the outdoor heat exchanger 11 are determined... 外 When the set defrosting start conditions are met, defrosting is controlled according to various frosting conditions of the outdoor condenser. Specifically, when the temperature T of the outdoor heat exchanger 11 is determined... 外 When the temperature exceeds the first set temperature threshold T1, it can be inferred that the frost is not severe. At this time, while operating in normal heating mode, the air inlet heat exchange module 211 is turned off and the air outlet heat exchange module 212 is turned on, thereby reducing the actual heat exchange area of ​​the indoor heat exchanger 21 and reducing the heat released by the indoor heat exchanger. This allows most of the heat in the circulating refrigerant to be directly transferred to the outdoor heat exchanger 11 for heat release, ensuring both heat exchange efficiency and ensuring that the indoor heat exchanger 21 can continuously supply heat to the indoor side when there is little frost, thus ensuring the continuity of heating and improving the thermal comfort experience.

[0071] Furthermore, when the temperature T of the outdoor heat exchanger 11 is determined... 外 When the temperature is less than or equal to the first set temperature threshold T1, it can be inferred that the frost is severe. At this time, the inlet-side heat exchange module 211 is turned on and the outlet-side heat exchange module 212 is turned off. The four-way valve 12 is also controlled to switch the refrigerant flow direction. After the four-way valve 12 is switched, the high-temperature refrigerant directly enters the outdoor heat exchanger 11 for defrosting. Moreover, when the refrigerant circulates indoors, it only passes through the inlet-side heat exchange module 211 and not the outlet-side heat exchange module 212. This ensures that the indoor evaporator does not transfer cold energy to the room when there is a lot of frost. While ensuring the defrosting effect, it improves the problem of a sudden drop in indoor temperature during the defrosting process, especially the obvious cold feeling on the side of the air conditioner outlet, thereby improving the user experience. The defrosting method provided in this embodiment ensures both the defrosting efficiency of the outdoor heat exchanger 11 and the heating comfort of the indoor side. It improves the defrosting rate without affecting the indoor heating comfort, and solves the problem that existing defrosting methods cannot balance defrosting efficiency and heating comfort.

[0072] In this embodiment, the inlet-side heat exchange module 211 and the outlet-side heat exchange module 212 each have independent flow paths, allowing refrigerant to pass through individually. Preferably, the inlet-side heat exchange module 211 and the outlet-side heat exchange module 212 are two independent heat exchangers, which can be installed independently or fixed together. The air inlet and air outlet of the indoor unit 20 of the air conditioner are usually located in different directions of the air conditioner, with the inlet-side heat exchange module 211 near the air inlet and the outlet-side heat exchange module 212 near the air outlet. Preferably, the air inlet and air outlet are located on opposite sides of the indoor unit 20, with the inlet-side heat exchange module 211 located on the side closer to the air inlet and the outlet-side heat exchange module 212 located on the side closer to the air outlet.

[0073] By dividing the indoor unit evaporator into an inlet-side heat exchange module 211 and an outlet-side heat exchange module 212, and linking it with the system's throttling valve and other control components during the defrosting of the outdoor unit 10, and controlling the defrosting of the inlet-side heat exchange module 211 and the outlet-side heat exchange module 212 according to various outdoor frost conditions, compared with the existing method of reducing the heat release of the indoor heat exchanger by simply controlling the indoor fan speed, it is not only easier to control, but also allows for flexible selection of the opening and closing of the inlet-side heat exchange module 211 and the outlet-side heat exchange module 212 according to the frost conditions. This ensures that the indoor heat exchanger 21 can continuously supply heat to the indoor side when there is little frost, and ensures that the indoor evaporator does not transfer cold energy to the indoor side when there is a lot of frost. This ensures both the defrosting efficiency of the outdoor heat exchanger 11 and the heating comfort of the indoor side.

[0074] Furthermore, in this embodiment, the defrosting mode includes at least two modes, corresponding to steps S104 and S105 respectively.

[0075] Preferably, in this embodiment, the defrosting modes include a first defrosting mode, a second defrosting mode, and a third defrosting mode. Combined with... Figure 4 As shown, when the temperature T of the outdoor heat exchanger 11 is determined... 外 When the temperature is ≤ the first set temperature threshold T1, the third defrosting mode is executed. In the third defrosting mode, the outlet heat exchange module 212 is first turned off and the inlet heat exchange module 211 is turned on. Then, the four-way valve 12 is reversed to switch the system flow route from heating mode to cooling mode. The defrosting is completed by using the heat of the compressor 13 and the refrigerant. Since the outlet heat exchange module 212 is turned off, not only will a part of the high-temperature refrigerant be stored in the outlet heat exchange module 212, which can dissipate heat to the air outlet, but when the refrigerant circulates in the room, it will only pass through the inlet heat exchange module 211 and will not pass through the outlet heat exchange module 212, effectively avoiding the problem of obvious coldness on the air outlet side.

[0076] Furthermore, when the temperature T of the outdoor heat exchanger 11 is determined... 外 >When the first set temperature threshold T1 is reached, the temperature T of the outdoor heat exchanger 11 is used as the reference. 外 The system can select between the first and second defrost modes within the specified temperature range to further improve the defrosting effect while reducing the impact on indoor temperature and ensuring continuous heating.

[0077] Specifically as follows:

[0078] Combination Figure 2 , Figure 3 , Figure 6 As shown, when the temperature T of the outdoor heat exchanger 11 is determined... 外 If the temperature exceeds the first set temperature threshold T1, the following steps will be performed:

[0079] Step S201: Determine the temperature T of the outdoor heat exchanger 11 外 Whether it is greater than or equal to the second set temperature threshold T2, wherein the first set temperature threshold T1 < the second set temperature threshold T2 < 0℃;

[0080] If yes, proceed to step S202; if no, proceed to step S203.

[0081] Step S202: Enter the first defrost mode (see...) Figure 2 As shown), the system controls the inlet side heat exchange module 211 to close and the outlet side heat exchange module 212 to open, while simultaneously reducing the speed of the indoor fan.

[0082] Step S203: Enter the second defrost mode (see...) Figure 3 As shown, the system controls the inlet heat exchange module 211 to close and the outlet heat exchange module 212 to open, while simultaneously controlling the indoor fan to close.

[0083] In the above embodiments, when T is detected 外 When the temperature reaches ≥T2, if the degree of frost is judged to be light and the frost layer is thin, the system enters the first defrosting mode. On the basis of heating operation, the system controls the air inlet side heat exchange module 211 to close through the first control valve 22, thereby reducing the actual heat exchange area of ​​the indoor heat exchanger 21, reducing the fan speed of the indoor unit 20, reducing the heat exchange efficiency of the indoor heat exchanger 21, and further reducing the heat released by the indoor heat exchanger 21. This allows most of the heat in the circulating refrigerant to run directly to the outdoor heat exchanger 11 for heat release, and this part of the heat is used for defrosting. At the same time, the refrigerant in the flow path of the indoor heat exchanger 21 is at high temperature, which will not affect the indoor heating comfort.

[0084] When T is detected 外 When the temperature is <T2, it is determined that the frost is moderate. On the basis of heating operation, the system controls the air inlet heat exchange module 211 to close through the first control valve 22, thereby reducing the actual heat exchange area of ​​the indoor heat exchanger 21 and controlling the indoor fan to close, further reducing the heat released by the indoor heat exchanger, so that more heat can be used for defrosting and improving the defrosting effect.

[0085] Compared to the conventional air conditioner that switches the refrigerant flow direction during defrosting, the indoor heat exchanger 21 uses low-temperature refrigerant, which radiates cold energy into the room, causing a certain degree of temperature drop. The first and second defrosting modes provided in this embodiment do not switch the refrigerant flow direction, so that the refrigerant inside the indoor unit 20 pipe is still high-temperature during defrosting, and the air inlet side heat exchange module 211 is controlled to be closed. Compared with the normal heating mode, the heat release is reduced, and the indoor temperature rise effect is reduced. However, since only half of the indoor heat exchanger 21 is closed, the temperature drop will not be too much. Moreover, since the fan speed is reduced or the indoor fan is turned off at the same time, the air outlet temperature of the air conditioner will not decrease, and the air felt by the human body will not become cooler.

[0086] It should be explained that "reducing the speed of the indoor fan" in the first defrosting mode refers to a lower range of fan speed compared to normal heating operation.

[0087] In some embodiments, when entering the second defrost mode, combined with Figure 3 As shown, the following steps are also performed:

[0088] Step S2031: Control the bypass defrosting branch 102 between the outlet end of the compressor 13 of the air conditioner and the inlet end of the outdoor heat exchanger 11 to be connected, so that some high-temperature refrigerant can directly enter the outdoor heat exchanger 11 through the bypass defrosting branch 102 for defrosting.

[0089] In the above embodiment, when entering the second defrosting mode, the second throttle valve 15 is also controlled to open, so that a part of the high-temperature refrigerant directly enters the outdoor heat exchanger 11 for defrosting, and another part of the high-temperature refrigerant enters the air outlet side of the indoor heat exchanger 21, that is, the air outlet side heat exchange module 212. Compared with the first defrosting mode, the heat used for defrosting is increased, and the defrosting capacity is further improved. At the same time, the indoor heat exchanger contains high-temperature refrigerant, which will not affect the indoor heating comfort.

[0090] In some embodiments, combined with Figure 3 , Figure 7 As shown, while controlling the conduction of the bypass defrosting branch 102, the following steps are also performed:

[0091] Step S2032: Obtain the temperature T of the outlet side heat exchange module 212. 内 And indoor temperature T0;

[0092] Step S2033: By adjusting the opening of the throttle valve on the bypass defrosting branch 102, the temperature T of the heat exchange module 212 on the air outlet side is reduced. 内 It is greater than the indoor temperature T0, and the difference between it and the indoor temperature T0 is greater than the set temperature difference △T.

[0093] In the above embodiment, a second throttle valve 15 is provided on the bypass defrosting branch 102. When the second throttle valve 15 is completely closed, the high-temperature refrigerant flows directly from the compressor 13 to the indoor unit 20. When the second throttle valve 15 is opened, the high-temperature refrigerant flows from the compressor 13 and is divided, with one part flowing to the indoor unit 20 and the other part flowing to the outdoor unit 10. The flow distribution of the two parts is controlled by adjusting the opening degree of the second throttle valve 15. When the opening degree of the second throttle valve 15 decreases, more refrigerant flows to the indoor unit 20; when the opening degree of the second throttle valve 15 increases, more refrigerant flows to the outdoor unit 10. The more high-temperature refrigerant in the indoor unit 20, the higher the temperature T of the outlet side heat exchange module 212. 内The higher the temperature, the higher the outlet air temperature; conversely, the lower the temperature, the less high-temperature refrigerant there is. Therefore, the temperature T of the outlet-side heat exchange module 212 can be adjusted by controlling the opening of the throttle valve. 内 By controlling T 内 -T0>△T can effectively prevent insufficient high-temperature refrigerant from flowing to the indoor unit 20, which would cause a significant drop in indoor temperature and affect the user's comfort experience.

[0094] In some embodiments, the temperature difference ΔT is set to be between 4°C and 6°C. Preferably, ΔT = 5°C.

[0095] In some embodiments, the defrosting start conditions include normal start conditions, which include: the heating operation time t is greater than or equal to a set time t1, and the temperature T of the outdoor heat exchanger 11 is... 外 The temperature is less than or equal to the set defrost start temperature, wherein the second set temperature threshold T2 < set defrost start temperature ≤ 0℃.

[0096] When the heating operation time t and the temperature T of the outdoor heat exchanger 11 are determined... 外 If the normal startup conditions are met, the subsequent determination of the temperature T of the outdoor heat exchanger 11 will proceed normally. 外 The step of determining whether the temperature exceeds the first set temperature threshold T1 is executed, i.e., steps S103 to S105.

[0097] In the above embodiment, when the heating operation time is detected to reach time t1, and T 外 When the temperature is ≤ the set defrost start temperature, defrosting will begin. The set defrost start temperature can be equal to 0℃ or less than 0℃. For example, if the set defrost start temperature is -1℃, defrosting will begin when T is detected. 外 When the temperature is below -1℃, defrosting will begin, and the appropriate defrosting mode will be determined. This embodiment does not limit the specific value of the defrosting start temperature.

[0098] In some embodiments, the defrosting start condition setting further includes an emergency start condition, the emergency start condition including:

[0099] The heating operation time t is less than the set time t1, but the temperature T of the outdoor heat exchanger 11 is... 外 Less than or equal to the third set temperature threshold T3, and the third set temperature threshold T3 < the first set temperature threshold T1;

[0100] When the heating operation time t and the temperature T of the outdoor heat exchanger 11 are determined... 外 When the aforementioned emergency start conditions are met, the system will directly enter the third defrosting mode.

[0101] The third defrosting mode includes: controlling the inlet side heat exchange module 211 to be turned on, the outlet side heat exchange module 212 to be turned off, and controlling the four-way valve 12 to switch the refrigerant flow direction.

[0102] In the above embodiment, if T is detected when the heating mode is first activated... 外 If the value is ≤T3, it indicates that the frost is already quite severe, and the system will enter the third defrosting mode to eliminate the frost on the outdoor heat exchanger 11 as soon as possible.

[0103] In this embodiment, when "t≥t1 and T 外 <T1” or “T” 外 When T3 ≤ T1, it is determined that the condenser of the outdoor unit 10 has severe frost buildup and a thick frost layer. Therefore, the third defrosting mode is entered. The indoor unit 20 fan is shut off, the first throttle valve 14 and the first control valve 22 are opened, and the second control valve 23 and the second throttle valve 15 are closed. Then, the four-way valve 12 is reversed. After the indoor fan is shut off and the second control valve 23 is closed, the refrigerant in the outlet pipe of the indoor heat exchanger 21 is high-temperature refrigerant. After the four-way valve 12 is reversed, the high-temperature refrigerant directly enters the outdoor heat exchanger 11 for defrosting. During indoor circulation, it passes through the inlet-side heat exchange module 211 but not the outlet-side heat exchange module 212, thus increasing the defrosting rate without affecting indoor heating comfort.

[0104] In some embodiments, during the defrosting process, when it is determined that the air conditioner meets the preset defrosting exit conditions, the defrosting mode is exited and the normal heating mode is restored.

[0105] Among them, the defrosting exit conditions include the temperature T of the outdoor heat exchanger 11. 外 The defrost exit temperature is greater than or equal to the set defrost exit temperature, or the defrost run time is greater than the set duration.

[0106] Preferably, in this embodiment, when the temperature T of the outdoor heat exchanger 11 is detected... 外 When the defrost exit temperature is greater than or equal to the set defrost exit temperature, the defrost mode will be exited and the normal heating mode will be restored. The set defrost exit temperature is greater than 0℃.

[0107] In this embodiment, the third set temperature threshold T3 < the first set temperature threshold T1 < the second set temperature threshold T2 < the set defrost start temperature T 启动 ≤0℃<Set defrost exit temperature T 退出 That is, T3 < T1 < T2 < T 启动 <T4≤0℃<T 退出 .

[0108] The third set temperature threshold T3 is -12 to -9℃; the first set temperature threshold T1 is -9 to -5℃; the second set temperature threshold T2 is -5 to -3℃; the set defrost start temperature T...启动 Between -2°C and 0°C; the set defrost exit temperature T 退出 At 5–8℃.

[0109] The following is combined with Figures 1 to 4 as well as Figure 7 The judgment logic and principle of the defrosting method in this embodiment will be introduced.

[0110] This embodiment provides a defrosting control method to improve thermal comfort. The air conditioner includes a compressor 13, a four-way valve 12, an outdoor heat exchanger 11, a first throttling valve 14, a first control valve 22, a second control valve 23, a second throttling valve 15, and an indoor heat exchanger 21. The indoor heat exchanger 21 is divided into an inlet-side heat exchange module 211 and an outlet-side heat exchange module 212. The method utilizes a defrosting control system that links various throttling valves to handle different outdoor frosting conditions.

[0111] During the heating operation of the air conditioner, the second throttle valve 15 is completely closed, the first control valve 22 and the second control valve 23 are completely open, and the opening degree of the first throttle valve 14 is intelligently adjusted according to the heating operation mode.

[0112] During heating operation, the pipe temperature T of outdoor heat exchanger 11 is continuously monitored. 外 The heating duration t is used to cyclically determine whether "t is less than t1 and T is less than t2". 外 ≤T3”: If so, proceed directly to the third defrosting mode;

[0113] If not, loop to check if "t≥t1":

[0114] If not, return "Continuously monitor the pipe temperature T of outdoor heat exchanger 11 during heating operation". 外 Heating duration t”;

[0115] If so, then determine T. 外 Is it less than or equal to T? 启动 If not, return "Continuously monitor the pipe temperature T of outdoor heat exchanger 11 during heating operation". 外 Heating duration t”;

[0116] If so, then loop to check if "T" is true. 外 ≥T2”:

[0117] If so, then enter the first defrosting mode.

[0118] If not, then loop to check if "T1 < T". 外 <T2”:

[0119] If so, then proceed to the second defrosting mode;

[0120] If not, then proceed to the third defrosting mode.

[0121] During the defrosting process until "T" is detected 外 ≥T 退出 When the time comes, exit defrosting mode and run in the set heating mode.

[0122] It should be noted that t1 above is the set value for heating operation time, which can be set according to the air conditioner system configuration and actual test conditions; T3 < T1 < T2 < T 启动 <T4≤0℃<T 退出 To differentiate the severity of condenser frosting on outdoor unit 10, the set value is the temperature T on the surface of outdoor heat exchanger 11 at the defrosting moment. 外 The lower the temperature, the more severe the frost formation on the outdoor heat exchanger 11.

[0123] When t≥t1 and T 外 When T2 is ≥, the first defrosting mode is entered. At this time, the first control valve 22 is closed, the second control valve 23 is fully open, the first throttle valve 14 is intelligently adjusted according to the defrosting mode, the second throttle valve 15 is fully closed, and the indoor fan speed is reduced to the preset speed.

[0124] When t≥t1 and T1<T 外 When T2 < T2, the second defrosting mode is entered. At this time, the first control valve 22 is closed, the second throttle valve 15 is open, the first throttle valve 14 is intelligently adjusted according to the defrosting mode, the second control valve 23 is fully open, the indoor fan is turned off, and the opening of the second throttle valve 15 is adjusted through feedback to control the tube temperature T of the heat exchanger on the air outlet side. 内 >Indoor ambient temperature +5℃.

[0125] When "t≥t1 and T 外 <T1” or “T” 外 When ≤T3”, the third defrosting mode is entered. At this time, the indoor fan is turned off, the second control valve 23 is closed, the first throttle valve 14 is intelligently adjusted according to the defrosting mode, the second throttle valve 15 is completely closed, the first control valve 22 is fully opened, and then the four-way valve 12 is reversed.

[0126] According to an embodiment of the present invention, in another aspect, a defrosting system is provided, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the defrosting method of any of the above embodiments.

[0127] According to an embodiment of the present invention, in another aspect, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the defrosting method of any of the above embodiments.

[0128] According to an embodiment of the present invention, on the other hand, such as Figures 1 to 4As shown, an air conditioner is provided, which is defrosted using any of the defrosting methods described above. The air conditioner includes an indoor unit 20 and an outdoor unit 10. The indoor unit 20 includes a casing and an indoor heat exchanger 21, wherein the casing is provided with an air inlet and an air outlet. The indoor heat exchanger 21 includes an air inlet-side heat exchange module 211 and an air outlet-side heat exchange module 212 arranged sequentially along the air inlet and outlet directions of the indoor unit 20. The air inlet-side heat exchange module 211 is located near the air inlet, and the air outlet-side heat exchange module 212 is located near the air outlet.

[0129] Preferably, the air inlet and air outlet are located on opposite sides of the indoor unit 20.

[0130] In some embodiments, such as Figure 1 As shown, the outdoor unit 10 includes a compressor 13, a four-way valve 12, a first throttle valve 14, and an outdoor heat exchanger 11. The air conditioner also includes a main circuit 101, a first branch circuit 1011 and a second branch circuit 1012, a first control valve 22, and a second control valve 23. The main circuit 101 is formed by connecting the compressor 13, the four-way valve 12, the indoor heat exchanger 21, the first throttle valve 14, and the outdoor heat exchanger 11 in series. The main circuit 101 includes a first pipe connecting the outlet end of the four-way valve 12 and the inlet end of the indoor heat exchanger 21, and a second pipe connecting the outlet end of the indoor heat exchanger 21 and the inlet end of the outdoor heat exchanger 11. The inlet-side heat exchange module 211 and the outlet-side heat exchange module 212 are connected in parallel on the main circuit 101. The outlet end of the first pipeline branches to form a first branch 1011 and a second branch 1012. The first branch 1011 connects the four-way valve 12 to the inlet end of the inlet-side heat exchange module 211, and the second branch 1012 connects the four-way valve 12 to the inlet end of the outlet-side heat exchange module 212. A first control valve 22 is provided on the first branch 1011 and is suitable for controlling the on / off state of the first branch 1011. A second control valve 23 is provided on the second branch 1012 and is suitable for controlling the on / off state of the second branch 1012.

[0131] In the above embodiments, the first throttle valve 14 is preferably an electronic expansion valve, and the first control valve 22 and the second control valve 23 can be electronic expansion valves or solenoid valves. Preferably, the first control valve 22 and the second control valve 23 are also electronic expansion valves, which can control the on / off of the air inlet heat exchange module 211 and the air outlet heat exchange module 212, and also control the flow rate.

[0132] In some embodiments, the air conditioner further includes a bypass defrosting branch 102 and a second throttle valve 15. The bypass defrosting branch 102 is connected between the first pipeline and the second pipeline, and the bypass defrosting branch 102 is arranged in parallel with the indoor heat exchanger 21. The second throttle valve 15 is disposed on the bypass defrosting branch 102 and is adapted to control the on / off state and flow rate of the bypass defrosting branch 102.

[0133] The air conditioner provided in this embodiment includes a compressor 13, an outdoor heat exchanger 11, an indoor heat exchanger 21, a first throttle valve 14, a four-way valve 12, a second throttle valve 15, a first control valve 22, and a second control valve 23. The indoor heat exchanger 21 has two parts: an air inlet heat exchanger near the air inlet side of the indoor unit 20 and an air outlet heat exchanger near the air outlet side of the indoor unit 20. Both the air inlet and outlet heat exchangers contain heat exchange tubes arranged in a serpentine pattern. These heat exchange tubes are not interconnected but are connected in parallel to the main circuit 101. A four-way valve 12 is used to switch the refrigerant flow direction and switch between cooling and heating modes. A four-way valve 12 is provided in both cooling and heating air conditioners. A second throttle valve 15 controls the opening and closing of the bypass defrosting branch 102 of the compressor 13. A first control valve 22 controls the opening and closing of the refrigerant flow path in the air inlet heat exchanger. A second control valve 23 controls the opening and closing of the refrigerant flow path in the air outlet heat exchanger.

[0134] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A defrosting method for an air conditioner, characterized in that, The indoor heat exchanger (21) of the air conditioner includes an air inlet side heat exchange module (211) and an air outlet side heat exchange module (212) arranged sequentially along the air inlet and outlet directions of the indoor unit (20). The defrosting method includes the following steps: Control the air conditioner to start the heating mode, and obtain the heating operation time t and the temperature T of the outdoor heat exchanger (11). 外 ; When the heating operation time t and the temperature T of the outdoor heat exchanger (11) are determined... 外 When the set defrosting start conditions are met, defrosting will begin; And further determine the temperature T of the outdoor heat exchanger (11). 外 Is it greater than the first set temperature threshold T1? If yes, then control the inlet side heat exchange module (211) to close and the outlet side heat exchange module (212) to open; if no, then control the inlet side heat exchange module (211) to open and the outlet side heat exchange module (212) to close, and control the four-way valve (12) of the air conditioner to switch the refrigerant flow direction; When the temperature T of the outdoor heat exchanger (11) is determined... 外 If the temperature exceeds the first set temperature threshold T1, the following steps will be performed: Determine the temperature T of the outdoor heat exchanger (11) 外 Whether it is greater than or equal to the second set temperature threshold T2, wherein the first set temperature threshold T1 < the second set temperature threshold T2 < 0℃; If so, the system enters the first defrosting mode, controls the air inlet heat exchange module (211) to close and the air outlet heat exchange module (212) to open, and simultaneously controls the indoor fan speed to decrease. If not, then enter the second defrosting mode, control the air inlet heat exchange module (211) to close and the air outlet heat exchange module (212) to open, and control the indoor fan to close at the same time; Upon entering the second defrost mode, the following steps are also performed: The bypass defrosting branch (102) between the outlet end of the compressor (13) of the air conditioner and the inlet end of the outdoor heat exchanger (11) is opened, so that some high-temperature refrigerant directly enters the outdoor heat exchanger (11) through the bypass defrosting branch (102) for defrosting. While controlling the conduction of the bypass defrosting branch (102), the following steps are also performed: Obtain the temperature T of the outlet side heat exchange module (212) 内 And indoor temperature T0; By adjusting the opening of the throttle valve on the bypass defrosting branch (102), the temperature T of the heat exchange module (212) on the air outlet side is adjusted. 内 It is greater than the indoor temperature T0, and the difference between it and the indoor temperature T0 is greater than the set temperature difference ΔT.

2. The defrosting method according to claim 1, characterized in that, The set temperature difference ΔT is between 4℃ and 6℃.

3. The defrosting method according to claim 1, characterized in that, The defrosting start conditions include normal start conditions, which include: The heating operation time t is greater than or equal to the set time t1, and the temperature T of the outdoor heat exchanger (11) is... 外 Less than or equal to the set defrost start temperature, wherein the second set temperature threshold T2 < set defrost start temperature ≤ 0℃; When the heating operation time t and the temperature T of the outdoor heat exchanger (11) are determined... 外 When the normal start-up conditions are met, the subsequent determination of the temperature T of the outdoor heat exchanger (11) is performed normally. 外 The step of determining whether the temperature exceeds the first set temperature threshold T1.

4. The defrosting method according to any one of claims 1 to 3, characterized in that, The defrosting start conditions also include emergency start conditions, which include: The heating operation time t is less than the set time t1, but the temperature T of the outdoor heat exchanger (11) is less than the set time t1. 外 Less than or equal to the third set temperature threshold T3, and the third set temperature threshold T3 < the first set temperature threshold T1; When the heating operation time t and the temperature T of the outdoor heat exchanger (11) are determined... 外 When the aforementioned emergency start conditions are met, the system will directly enter the third defrosting mode. The third defrosting mode includes: controlling the air inlet heat exchange module (211) to be turned on and the air outlet heat exchange module (212) to be turned off, and controlling the four-way valve (12) to switch the refrigerant flow direction.

5. The defrosting method according to any one of claims 1 to 3, characterized in that, During the defrosting process, when it is determined that the air conditioner meets the preset defrosting exit conditions, the defrosting mode is exited and the normal heating mode is restored. The defrosting exit condition includes the temperature T of the outdoor heat exchanger (11). 外 The defrost exit temperature is greater than or equal to the set defrost exit temperature, or the defrost run time is greater than the set duration.

6. A defrosting system, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the defrosting method according to any one of claims 1 to 5.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the defrosting method according to any one of claims 1 to 5.

8. An air conditioner, wherein the defrosting method according to any one of claims 1 to 5 is used for defrosting, characterized in that, The air conditioner includes an indoor unit (20) and an outdoor unit (10), wherein the indoor unit (20) includes: The housing has an air inlet and an air outlet respectively. The indoor heat exchanger (21) includes an air inlet side heat exchange module (211) and an air outlet side heat exchange module (212) arranged sequentially along the air inlet and outlet directions of the indoor unit (20). The air inlet heat exchange module (211) is located near the air inlet, and the air outlet heat exchange module (212) is located near the air outlet.

9. The air conditioner according to claim 8, characterized in that, The outdoor unit (10) includes a compressor (13), a four-way valve (12), a first throttle valve (14), and an outdoor heat exchanger (11). The air conditioner also includes: The main circuit (101) is formed by connecting the compressor (13), the four-way valve (12), the indoor heat exchanger (21), the first throttle valve (14) and the outdoor heat exchanger (11) in series. The main circuit (101) includes a first pipeline connecting the outlet end of the four-way valve (12) and the inlet end of the indoor heat exchanger (21), and a second pipeline connecting the outlet end of the indoor heat exchanger (21) and the inlet end of the outdoor heat exchanger (11). The first branch (1011) and the second branch (1012) are connected in parallel on the main circuit (101) and the air inlet heat exchange module (211) and the air outlet heat exchange module (212) are connected in parallel. The outlet end of the first pipeline branches to form the first branch (1011) and the second branch (1012). The first branch (1011) connects the four-way valve (12) and the inlet end of the air inlet heat exchange module (211), and the second branch (1012) connects the four-way valve (12) and the inlet end of the air outlet heat exchange module (212). A first control valve (22) and a second control valve (23), wherein the first control valve (22) is disposed on the first branch (1011) and is adapted to control the opening and closing of the first branch (1011), and the second control valve (23) is disposed on the second branch (1012) and is adapted to control the opening and closing of the second branch (1012).

10. The air conditioner according to claim 9, characterized in that, The air conditioner also includes: A bypass defrosting branch (102) is connected between the first pipeline and the second pipeline, and the bypass defrosting branch (102) is connected in parallel with the indoor heat exchanger (21); The second throttle valve (15) is installed on the bypass defrosting branch (102) and is suitable for controlling the on / off state and flow rate of the bypass defrosting branch (102).

Images