Air conditioner and control method of air conditioner

Abstract

The present invention provides an air conditioner, comprising a compressor, an indoor unit, and an outdoor unit. The indoor unit comprises a plurality of indoor heat exchangers, and the exhaust port of the compressor can be selectively connected to at least one indoor heat exchanger through a four-way valve; the outdoor unit comprises an outdoor heat exchanger, and the outdoor heat exchanger can be selectively connected to at least one indoor heat exchanger through a four-way valve and a three-way valve body assembly. As needed, refrigerant can flow into one or more indoor heat exchangers for cooling adjustment to defrost the outdoor air conditioner, thereby avoiding frequent reversing of the four-way valve, thereby increasing the reliability of the air-conditioning system, and making the indoor temperature drop controllable. After defrosting is completed and heating is resumed, the hot air in the room can be blown out in time, thereby improving the user experience.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to an air conditioner and a control method of the air conditioner. Background Art

[0002] When the air conditioner is running in winter heating mode, when the outdoor heat exchanger temperature is lower than the dew point temperature of the humid air and the outdoor heat exchanger temperature is lower than 0°C, the water vapor in the air will condense into a frost layer on the surface of the outdoor heat exchanger. The frost layer will increase the thermal resistance of the outdoor heat exchanger, causing the heating capacity to decay. In order to ensure the heating performance, when the frost layer grows to a certain extent, the outdoor heat exchanger needs to be defrosted.

[0003] Existing air conditioners usually use the "reverse cycle defrosting" method for defrosting, that is, the air conditioner switches from heating mode to cooling mode by switching the four-way valve during defrosting. However, this method has many disadvantages. On the one hand, the indoor fan stops rotating during defrosting, and the surface temperature of the indoor heat exchanger is as low as -20°C, which will absorb a large amount of heat from the indoor side. There is no heat supplement in the room during defrosting, which causes the room temperature to drop significantly. After defrosting is completed and heating is resumed, hot air cannot be blown out for a long time in the room, affecting indoor comfort. On the other hand, in low temperature and high humidity areas such as the Yangtze River Basin, the frequent frost in winter causes the four-way valve to switch frequently, resulting in poor reliability of the air conditioner. Summary of the invention

[0004] The main purpose of the present invention is to provide an air conditioner and a control method for the air conditioner to solve the problem of large indoor temperature drop during reverse cycle defrosting in the prior art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided an air conditioner, comprising: a compressor, an indoor unit, and an outdoor unit, wherein the indoor unit comprises a plurality of indoor heat exchangers, and the exhaust port of the compressor is selectively connected to at least one indoor heat exchanger via a four-way valve; the outdoor unit comprises an outdoor heat exchanger, and the outdoor heat exchanger is selectively connected to at least one indoor heat exchanger via a four-way valve and a three-way valve body assembly.

[0006] Furthermore, the three-way valve body assembly includes a first three-way valve and a second three-way valve, and the heat exchange pipeline of the outdoor unit is connected to the heat exchange pipeline of the indoor unit through the first three-way valve and the second three-way valve.

[0007] Further, the plurality of indoor heat exchangers include a first indoor heat exchanger and a second indoor heat exchanger. The inlet of the first indoor heat exchanger is connected to an outlet of the first three-way valve, and the inlet of the first three-way valve is connected to the outlet of the outdoor unit; the inlet of the second indoor heat exchanger is connected to the inlet of the first indoor heat exchanger, and the outlet of the second indoor heat exchanger is connected through the inlet of the second three-way valve, and one outlet of the second three-way valve is connected to the four-way valve through a pipeline, and a first connecting branch is provided between the other outlet of the first three-way valve and the other outlet of the second three-way valve.

[0008] Furthermore, the air conditioner also includes a first two-way valve, a second two-way valve, a third two-way valve and a fourth two-way valve. The first two-way valve and the second two-way valve are arranged on the pipeline between the outlet of the first indoor heat exchanger and the inlet of the second indoor heat exchanger, and the third two-way valve and the fourth two-way valve are arranged on the first connecting branch.

[0009] Furthermore, the air conditioner also includes a second connecting branch, a first end of the second connecting branch is arranged on the pipeline connecting the first two-way valve and the second two-way valve, and a second connecting branch, a second end of the second connecting branch is arranged on the pipeline connecting the third two-way valve and the fourth two-way valve.

[0010] According to another aspect of the present invention, a control method for an air conditioner is provided, the control method is used to control the above-mentioned air conditioner, the control method comprising the following steps: when it is determined that the air conditioner enters a defrost mode, obtaining temperature information, wherein the temperature information at least includes the indoor ambient temperature, the indoor wall temperature and the set temperature of the air conditioner; generating a control instruction set based on the temperature information, and controlling the air conditioner to execute a target defrost mode based on the control instruction set, wherein the target defrost mode includes a plurality of defrost modes.

[0011] Furthermore, a control instruction set is generated based on the temperature information, and the air conditioner is controlled to execute a target defrost mode based on the control instruction set, including: when the difference between the set temperature and the ambient temperature is greater than or equal to a first preset value, a first control instruction in the control instruction set is generated, and the first control instruction is used to control the air conditioner to execute a first defrost mode in the target defrost mode.

[0012] Furthermore, the process of controlling the air conditioner to execute the first defrost mode includes: controlling the outdoor fan to turn off, controlling the throttle valve to open to the maximum opening, controlling the first three-way valve, the second three-way valve and the fourth three-way valve to cut off power, and controlling the second three-way valve, the first two-way valve and the third two-way valve to turn on power.

[0013] Furthermore, the process of controlling the air conditioner to execute the first defrost mode includes: collecting the temperature of the indoor heat exchanger; when it is determined that the temperature of the indoor heat exchanger is greater than or equal to a second preset value, controlling the first indoor fan to operate at a first target speed, controlling the first electric heater to turn off, controlling the second indoor fan to turn off, and controlling the second electric heater to turn off; when it is determined that the temperature of the indoor heat exchanger is less than the second preset value, controlling the first indoor fan to operate at the first target speed, controlling the first electric heater to turn on, controlling the second indoor fan to turn off, and controlling the second electric heater to turn off.

[0014] Furthermore, a control instruction set is generated based on the temperature information, and the air conditioner is controlled to execute a target defrost mode based on the control instruction set, including: when it is determined that the difference between the ambient temperature and the wall temperature is greater than or equal to a third preset value, a second control instruction in the control instruction set is generated, and the second control instruction is used to control the air conditioner to execute a second defrost mode in the target defrost mode.

[0015] Furthermore, the process of controlling the air conditioner to execute the second defrost mode includes: controlling the outdoor fan to turn off, controlling the throttle valve to open to the maximum, controlling the first three-way valve, the second two-way valve and the fourth two-way valve to be energized, and controlling the second three-way valve, the first two-way valve and the third two-way valve to be de-energized.

[0016] Furthermore, the process of controlling the air conditioner to execute the second defrost mode includes: collecting the temperature of the indoor heat exchanger; when it is determined that the temperature of the indoor heat exchanger is greater than or equal to a second preset value, controlling the first electric heater to turn off, controlling the second indoor fan to turn off, controlling the second electric heater to turn off, controlling the first indoor fan to turn off and the first electric heater to turn off, controlling the second indoor fan to run at a first target speed, and controlling the second electric heater to turn off.

[0017] Furthermore, the method also includes: generating a third control instruction when it is determined that the temperature of the indoor heat exchanger is less than a second preset value, the third control instruction being used to control the air conditioner to execute a third defrost mode.

[0018] Furthermore, the process of controlling the air conditioner to perform the third defrost mode includes: controlling the outdoor fan to turn off, controlling the throttle valve to open to the maximum, controlling the first three-way valve and the second three-way valve to be energized, controlling the first two-way valve and the second two-way valve to be de-energized, controlling the third two-way valve and the fourth two-way valve to be energized, controlling the indoor fan to turn off, controlling the first heater to turn off, controlling the second indoor fan to turn off, and controlling the second electric heater to turn off.

[0019] By applying the technical solution of the present invention, the compressor is connected to at least one indoor heat exchanger through a four-way valve, and the gas in the compressor can flow into the indoor reversing device through the four-way valve, or the refrigerant in the indoor reversing device flows into the compressor through the four-way valve. The flow direction of the refrigerant is changed by the four-way valve, and then the refrigerant in the outdoor heat exchanger can flow into the indoor heat exchanger to realize air-conditioning cooling, or the refrigerant in the indoor heat exchanger can flow into the outdoor heat exchanger to realize air-conditioning heating. The outdoor heat exchanger can be connected to one or more indoor heat exchangers according to the selection. The refrigerant can flow into one or more indoor heat exchangers for cooling adjustment as needed to defrost the outdoor air conditioner, avoiding frequent reversing of the four-way valve, thereby increasing the reliability of the air-conditioning system, and the indoor temperature drop is controllable. After defrosting is completed and heating is resumed, the hot air in the room can be blown out in time, and the experience is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 A schematic diagram showing the system structure of a first embodiment of an air conditioner according to the present invention is shown;

[0022] Figure 2 A schematic diagram of a refrigeration cycle of a second embodiment of an air conditioner according to the present invention is shown;

[0023] Figure 3 A schematic diagram of a heating cycle according to a third embodiment of an air conditioner of the present invention is shown;

[0024] Figure 4 A schematic diagram showing a first defrosting state of a fourth embodiment of an air conditioner according to the present invention is shown;

[0025] Figure 5 A schematic diagram showing a second defrosting state of a fifth embodiment of an air conditioner according to the present invention is shown;

[0026] Figure 6 A schematic diagram showing a third defrosting state of a sixth embodiment of an air conditioner according to the present invention is shown;

[0027] Figure 7 A control flow chart showing a first embodiment of a method for controlling an air conditioner according to the present invention is shown;

[0028] Figure 8 A defrosting control flow chart of a second embodiment of a control method for an air conditioner according to the present invention is shown;

[0029] Fig. 9 A first defrosting state control flow chart of a third embodiment of a control method for an air conditioner according to the present invention is shown;

[0030] Fig.10 A second defrosting state control flow chart of a fourth embodiment of a control method for an air conditioner according to the present invention is shown;

[0031] Fig.11 A control flow chart of the third defrosting state of the fifth embodiment of the control method of the air conditioner according to the present invention is shown.

[0032] The above drawings include the following reference numerals:

[0033] 10. Compressor;

[0034] 20. Four-way valve;

[0035] 30. Outdoor heat exchanger;

[0036] 40. External fan;

[0037] 50. Throttle valve;

[0038] 61. First three-way valve; 62. Second three-way valve;

[0039] 71, first two-way valve; 72, second two-way valve; 73, third two-way valve; 74, fourth two-way valve;

[0040] 81. a first electric heater; 82. a second electric heater;

[0041] 91. first internal fan; 92. second internal fan;

[0042] 101. A first indoor heat exchanger; 102. A second indoor heat exchanger;

[0043] 103. A first connecting branch; 104. A second connecting branch. DETAILED DESCRIPTION

[0044] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0045] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0046] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0047] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in a variety of different forms and should not be construed as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for the sake of clarity, the thickness of the layers and regions may be enlarged, and the same reference numerals are used to represent the same devices, and thus their descriptions will be omitted.

[0048] Combination Figures 1 to 11 As shown, according to a specific embodiment of the present invention, an air conditioner is provided.

[0049] like Figure 1 As shown, specifically, the air conditioner includes a compressor 10, an indoor unit, and an outdoor unit. The indoor unit includes a plurality of indoor heat exchangers, and the exhaust port of the compressor 10 can be selectively connected to at least one indoor heat exchanger through a four-way valve 20; the outdoor unit includes an outdoor heat exchanger 30, and the outdoor heat exchanger 30 can be selectively connected to at least one indoor heat exchanger through the four-way valve 20 and the three-way valve body assembly.

[0050] In this embodiment, the compressor 10 is connected to at least one indoor heat exchanger through a four-way valve 20. The gas in the compressor 10 can flow into the indoor reversing device through the four-way valve 20, or the refrigerant in the indoor reversing device can flow into the compressor 10 through the four-way valve 20. The flow direction of the refrigerant is changed by the four-way valve 20, and then the refrigerant in the outdoor heat exchanger 30 can flow into the indoor heat exchanger to realize air-conditioning cooling, or the refrigerant in the indoor heat exchanger can flow into the outdoor heat exchanger 30 to realize air-conditioning heating. The outdoor heat exchanger 30 can be connected to one or more indoor heat exchangers according to the selection. The refrigerant can flow into one or more indoor heat exchangers for cooling adjustment as needed to defrost the outdoor air conditioner, avoiding frequent reversing of the four-way valve 20, thereby increasing the reliability of the air-conditioning system, and the indoor temperature drop is controllable. After defrosting is completed and heating is resumed, the hot air in the room can be blown out in time, and the experience is improved.

[0051] like Figures 1 to 6 As shown, the three-way valve body assembly includes a first three-way valve 61 and a second three-way valve 62. The heat exchange pipeline of the outdoor unit is connected to the heat exchange pipeline of the indoor unit through the first three-way valve 61 and the second three-way valve 62. The three-way valve is used to change the flow direction of the medium so that two mutually perpendicular channels can be connected. This arrangement allows the outdoor heat exchanger 30 to be controlled to be connected to one indoor heat exchanger or to two indoor heat exchangers at the same time as needed.

[0052] Further, the plurality of indoor heat exchangers include a first indoor heat exchanger 101 and a second indoor heat exchanger 102. The inlet of the first indoor heat exchanger 101 is connected to an outlet of the first three-way valve 61, and the inlet of the first three-way valve 61 is connected to the outlet of the outdoor unit; the inlet of the second indoor heat exchanger 102 is connected to the inlet of the first indoor heat exchanger 101, and the outlet of the second indoor heat exchanger 102 is connected through the inlet of the second three-way valve 62, and one outlet of the second three-way valve 62 is connected to the four-way valve 20 through a pipeline, and a first connecting branch 103 is provided between the other outlet of the first three-way valve 61 and the other outlet of the second three-way valve 62. , the first indoor heat exchanger 101 and the second indoor heat exchanger 102 are connected in series, the first three-way valve 61, the second three-way valve 62 and the four-way valve 20 can control the flow direction of the refrigerant so that the refrigerant can flow in from the inlet of the first indoor heat exchanger 101, and flow to the outdoor heat exchanger 30 through the first indoor heat exchanger 101 and the second indoor heat exchanger 102 to achieve refrigeration and defrosting, or the refrigerant can enter from the outlet of the second indoor heat exchanger 102, and flow to the outdoor heat exchanger 30 through the second indoor heat exchanger 102 and the first indoor heat exchanger 101 to achieve heating and defrosting.

[0053] Furthermore, the air conditioner also includes a first two-way valve 71, a second two-way valve 72, a third two-way valve 73 and a fourth two-way valve 74. The first two-way valve 71 and the second two-way valve 72 are arranged on the pipeline between the outlet of the first indoor heat exchanger 101 and the inlet of the second indoor heat exchanger 102. The third two-way valve 73 and the fourth two-way valve 74 are arranged on the first connecting branch 103. The two-way valve can control the flow or blocking of the branch. When the two-way valve is energized, the branch flows. When the two-way valve is de-energized, the branch is blocked. The first two-way valve 71 and the second two-way valve 72 are used to control the flow of the refrigerant between the first indoor heat exchanger 101 and the second indoor heat exchanger 102. The third two-way valve 73 and the fourth two-way valve 74 are used to control the flow direction of the refrigerant in the first connecting branch 103.

[0054] Furthermore, the air conditioner also includes a second connecting branch 104, a first end of the second connecting branch 104 is arranged on a pipeline connecting the first two-way valve 71 and the second two-way valve 72, and a second connecting branch 104, a second end of the second connecting branch 104 is arranged on a pipeline connecting the third two-way valve 73 and the fourth two-way valve 74. The second connecting branch 104 enables the first indoor heat exchanger 101 and the second indoor heat exchanger 102 to be connected in parallel. Under the control of the first two-way valve 71, the second two-way valve 72, the third two-way valve 73, and the fourth two-way valve 74, the refrigerant can pass only through the first indoor heat exchanger 101 or only through the second indoor heat exchanger 102 or through the first indoor heat exchanger 101 and the second indoor heat exchanger 102 or not through the first indoor heat exchanger 101 and the second indoor heat exchanger 102, so that the air conditioner has a variety of different defrost modes to choose from.

[0055] like Figure 7 As shown, according to another aspect of the present invention, a control method is also provided, which is used to control the above-mentioned air conditioner, and the control method includes the following steps: when it is determined that the air conditioner enters the defrost mode, obtaining temperature information, wherein the temperature information at least includes the indoor ambient temperature, the indoor wall temperature and the set temperature of the air conditioner; generating a control instruction set based on the temperature information, and controlling the air conditioner to execute a target defrost mode based on the control instruction set, and the target defrost mode includes multiple defrost modes.

[0056] In this embodiment, the control method is used to control the air conditioner to select a suitable defrost mode for defrosting according to actual conditions. Under multiple defrost modes, the air conditioner can meet different actual conditions and achieve the best defrost effect, avoiding frequent reversing of the four-way valve 20, which causes a decrease in system reliability.

[0057] like Figure 8As shown, a control instruction set is generated based on temperature information, and the air conditioner is controlled to execute a target defrost mode based on the control instruction set, including: when the difference between the set temperature and the ambient temperature is greater than or equal to a first preset value, a first control instruction in the control instruction set is generated, and the first control instruction is used to control the air conditioner to execute a first defrost mode in the target defrost mode. In the first defrost mode, the refrigerant only passes through the first indoor heat exchanger 101, and the second indoor heat exchanger 102 does not work.

[0058] Furthermore, the process of controlling the air conditioner to execute the first defrost mode includes: controlling the outdoor fan 40 to close, controlling the throttle valve 50 to open to the maximum opening, controlling the first three-way valve 61, the second three-way valve 62 and the fourth three-way valve to cut off power, and controlling the second three-way valve 62, the first two-way valve 71 and the third two-way valve 73 to turn on power, so that the refrigerant only flows through the first indoor heat exchanger 101.

[0059] like Fig. 9 As shown, the process of controlling the air conditioner to execute the first defrost mode includes: collecting the temperature of the indoor heat exchanger; when it is determined that the temperature of the indoor heat exchanger is greater than or equal to the second preset value, controlling the first indoor fan 91 to operate at the first target speed, controlling the first electric heater 81 to be turned off, controlling the second indoor fan 92 to be turned off, and controlling the second electric heater 82 to be turned off; when it is determined that the temperature of the indoor heat exchanger is less than the second preset value, controlling the first indoor fan 91 to operate at the first target speed, controlling the first electric heater 81 to be turned on, controlling the second indoor fan 92 to be turned off, and controlling the second electric heater 82 to be turned off. By turning on the first indoor fan 91, heat can be provided to the room from the downwind outlet to reduce the defrosting temperature drop; by turning on the first electric heater 81, the heat provided to the room can be further supplemented, so that the air outlet temperature during defrosting is higher and more comfortable.

[0060] Furthermore, a control instruction set is generated based on the temperature information, and the air conditioner is controlled to execute a target defrost mode based on the control instruction set, including: when it is determined that the difference between the ambient temperature and the wall temperature is greater than or equal to a third preset value, a second control instruction in the control instruction set is generated, and the second control instruction is used to control the air conditioner to execute a second defrost mode in the target defrost mode, so that the refrigerant only flows through the second indoor heat exchanger 102.

[0061] Among them, the first preset value is ΔT 1， The second preset value is T 预设 , the third preset value is ΔT2.

[0062] like Fig.10As shown, the process of controlling the air conditioner to execute the second defrost mode includes: controlling the outdoor fan 40 to be closed, controlling the throttle valve 50 to be opened to the maximum, controlling the first three-way valve 61, the second two-way valve 72 and the fourth two-way valve 74 to be energized, controlling the second three-way valve 62, the first two-way valve 71 and the third two-way valve 73 to be de-energized, and the refrigerant only flows through the second indoor heat exchanger 102, and the first indoor heat exchanger 101 does not work.

[0063] Furthermore, the process of controlling the air conditioner to execute the second defrost mode includes: collecting the temperature of the indoor heat exchanger; when it is determined that the temperature of the indoor heat exchanger is greater than or equal to the second preset value, controlling the first electric heater 81 to turn off, controlling the second indoor fan 92 to turn off, controlling the second electric heater 82 to turn off, controlling the first indoor fan 91 to turn off and the first electric heater 81 to turn off, controlling the second indoor fan 92 to run at the first target speed, and controlling the second electric heater 82 to turn off. By turning on the second indoor fan 92, heat can be provided to the room from the upwind outlet, thereby reducing the defrosting temperature drop. Since the upwind outlet is located at the upper part of the room, the wind does not blow on people. When the air outlet temperature is higher than the current indoor temperature, it can supply heat to the room. Therefore, there is no need to turn on the second electric heater 82, thereby saving electricity.

[0064] Furthermore, the method also includes: when it is determined that the temperature of the indoor heat exchanger is less than a second preset value, generating a third control instruction, the third control instruction is used to control the air conditioner to execute a third defrost mode. In the third defrost mode, the refrigerant does not flow through the first indoor heat exchanger 101 and the second indoor heat exchanger 102, does not supply heat to the room, nor absorb heat from the room, and the indoor temperature remains unchanged.

[0065] like Fig.11 As shown, the process of controlling the air conditioner to execute the third defrost mode includes: controlling the outdoor fan 40 to close, controlling the throttle valve 50 to open to the maximum, controlling the first three-way valve 61 and the second three-way valve 62 to be energized, controlling the first two-way valve 71 and the second two-way valve 72 to be de-energized, controlling the third two-way valve 73 and the fourth two-way valve 74 to be energized, controlling the indoor fan to close, controlling the first heater to close, controlling the second indoor fan 92 to close, and controlling the second electric heater 82 to close. In the third defrost state, the wall temperature and the indoor temperature are relatively high, and heat can be transferred to the outdoors for defrosting, without the need for defrosting with the help of the air conditioner, thereby improving the defrosting efficiency and saving electricity resources.

[0066] In another embodiment of the present application, the circulation system of the air conditioner is a heat pump system, the outdoor unit is composed of a compressor 10, a four-way valve 20, an outdoor heat exchanger 30, an outdoor fan 40, and a throttle valve 50, and the indoor unit is composed of a first three-way valve 61, a second three-way valve 62, a first two-way valve 71, a second two-way valve 72, a third two-way valve 73, a fourth two-way valve 74, a first indoor heat exchanger 101, a second indoor heat exchanger 102, a first indoor fan 91, a second indoor fan 92, a first electric heater 81, and a second electric heater 82.

[0067] Specifically, the second indoor heat exchanger 102 and the first indoor heat exchanger 101 are vertically arranged up and down, the second indoor heat exchanger 102 is located above the first indoor heat exchanger 101, the first indoor fan 91 and the second indoor fan 92 are arranged corresponding to the first indoor heat exchanger 101 and the second indoor heat exchanger 102 respectively, and the first electric heater 81 and the second electric heater 82 are arranged corresponding to the first indoor heat exchanger 101 and the second indoor heat exchanger 102 respectively; the first indoor fan 91, the first indoor heat exchanger 101 and the first electric heater 81 are close to the lower air outlet, and the second indoor fan 92, the second indoor heat exchanger 102 and the second electric heater 82 are close to the upper air outlet.

[0068] Specifically, the components of the heat pump system are connected by pipelines. A first two-way valve 71 and a second two-way valve 72 are provided between the first indoor heat exchanger 101 and the second indoor heat exchanger 102. The other end of the first indoor heat exchanger 101 is connected to the c end of the first three-way valve 61, and the other end of the second indoor heat exchanger 102 is connected to the f end of the second three-way valve 62; the a end of the first three-way valve 61 is connected to the throttle valve 50 of the outdoor unit, and the d end of the second three-way valve 62 is connected to the four-way valve 20 of the outdoor unit; the b end of the first three-way valve 61 is connected to the fourth two-way valve 74, and the other end of the fourth two-way valve 74 is connected to the third two-way valve 73, and the other end of the third two-way valve 73 is connected to the e end of the second three-way valve 62; there is a pipeline between the first two-way valve 71 and the second two-way valve 72, and the pipeline is connected between the third two-way valve 73 and the fourth two-way valve 74.

[0069] In this embodiment, the two-way valve can control the flow or blockage of the branch. When the two-way valve is in the power-on state, the branch flows, and when the two-way valve is in the power-off state, the branch is blocked. The three-way valve is used to switch the flow direction of the medium, and can connect two mutually perpendicular channels. When the first three-way valve 61 is in the power-off state, the ab end is connected; when the first three-way valve 61 is powered on, the valve switches to connect the ac end. When the second three-way valve 62 is in the power-off state, the de end is connected; when the second three-way valve 62 is powered on, the valve switches to connect the df end. By controlling the power-off and power-on of the two-way valve and the three-way valve, the refrigerant flow direction switching can be controlled, and the refrigerant can flow through the first indoor heat exchanger 101 and the second indoor heat exchanger 102, or only flow through the first indoor heat exchanger 101, or only flow through the second indoor heat exchanger 102, or not flow through the first indoor heat exchanger 101 and the second indoor heat exchanger 102.

[0070] When cooling or heating is performed: the first three-way valve 61 is in the off state, so that the ab end is connected; the second three-way valve 62 is in the off state, so that the de end is connected; the first two-way valve 71 and the second two-way valve 72 are energized, and the third two-way valve 73 and the fourth two-way valve 74 are off, so that the refrigerant flows through the first indoor heat exchanger 101 and the second indoor heat exchanger 102, such as Figure 2 , Figure 3 shown.

[0071] This circulation system can have multiple defrosting states: the first defrosting state: Figure 4 As shown, the first three-way valve 61 is in the de-energized state, so that the ab end is connected; the second three-way valve 62 is in the energized state, so that the df end is connected; the first two-way valve 71 and the third two-way valve 73 are energized, and the second two-way valve 72 and the fourth two-way valve 74 are de-energized, so that the refrigerant only flows through the first indoor heat exchanger 101. The second defrosting state: Figure 5 As shown, the first three-way valve 61 is energized, so that the ac end is connected; the second three-way valve 62 is de-energized, so that the de end is connected; the second two-way valve 72 and the fourth two-way valve 74 are energized, and the first two-way valve 71 and the third two-way valve 73 are de-energized, so that the refrigerant only flows through the second indoor heat exchanger 102. The third defrosting state: Figure 6 As shown, the first three-way valve 61 is energized, so that the ac end is connected; the second three-way valve 62 is energized, so that the df end is connected; the first two-way valve 71 and the second two-way valve 72 are de-energized, and the third two-way valve 73 and the fourth two-way valve 74 are energized, so that the refrigerant does not flow through the first indoor heat exchanger 101 and the second indoor heat exchanger 102.

[0072] When defrosting is performed, the defrost state to be entered is determined according to the preset value, and the opening state of the indoor fan and the electric heater is determined. The four-way valve 20 is controlled not to be reversed, the outdoor fan 40 is turned off, and the throttle valve 50 is opened to the maximum so that the refrigerant is not throttled at the throttle valve 50, and the hot air flows directly to the outdoor heat exchanger 30 for defrosting.

[0073] The control process of the present invention is as follows Figure 7 As shown, step one: the air conditioner enters defrost, and the defrost state to be entered is determined according to the preset value; step two: the on / off state of the two-way valve and the three-way valve is controlled according to the current defrost state, and the switch state of the internal fan and the electric heater is controlled according to the defrost state and the preset value.

[0074] The defrosting control method of the present invention is as follows Figure 8 As shown, when the air conditioner enters defrosting mode, the current indoor ambient temperature T is detected. 内环 、Current indoor wall temperature T 墙温 、Current user set temperature T 设定 ; If T is satisfied 设定 -T 内环 ≥ΔT1, the first defrosting state is performed; if not, it is determined whether T 内环 -T 墙温 ≥ΔT2; if satisfied, proceed to the second defrost state, otherwise proceed to the third defrost state.

[0075] The first defrost state control process is as follows Fig. 9 As shown, the air conditioner enters the first defrosting state; the outdoor fan 40 is turned off, the throttle valve 50 is opened to the maximum, the first three-way valve 61, the second two-way valve 72, and the fourth two-way valve 74 are powered off, and the second three-way valve 62, the first two-way valve 71, and the third two-way valve 73 are powered on; the current indoor heat exchanger temperature T is detected. 内管 ; If T is satisfied 内管 ≥T 预设 ,, the first inner fan 91 is operated at a speed of X, the first electric heater 81 is turned off, the second inner fan 92 is turned off, and the second electric heater 82 is turned off. Otherwise, the first inner fan 91 is operated at a speed of X, the first electric heater 81 is turned on, the second inner fan 92 is turned off, and the second electric heater 82 is turned off.

[0076] The second defrost state control process is as follows Fig.10 As shown, the air conditioner enters the second defrost state; the outdoor fan 40 is turned off, the throttle valve 50 is opened to the maximum, the first three-way valve 61, the second two-way valve 72, and the fourth two-way valve 74 are energized, and the second three-way valve 62, the first two-way valve 71, and the third two-way valve 73 are de-energized; the first indoor fan 91 is turned off, the first electric heater 81 is turned off, the second indoor fan 92 runs at a speed X, and the second electric heater 82 is turned off.

[0077] The third defrost state control process is as follows Fig.11As shown, the air conditioner enters the third defrost state; the outdoor fan 40 is turned off, the throttle valve 50 is opened to the maximum, the first three-way valve 61 and the second three-way valve 62 are energized, the first two-way valve 71 and the second two-way valve 72 are de-energized, and the third two-way valve 73 and the fourth two-way valve 74 are energized; the first indoor fan 91 is turned off, the first electric heater 81 is turned off, the second indoor fan 92 is turned off, and the second electric heater 82 is turned off.

[0078] When the air conditioner enters defrosting mode, it first determines the current indoor ambient temperature T 内环 , and the current user set temperature T 设定 Whether the difference meets the preset temperature difference 1ΔT1, if it meets T 设定 -T 内环 ≥ΔT1, it indicates that when the current indoor ambient temperature is significantly different from the user's preset temperature and the indoor temperature is still in the heating state, it is necessary to add a large amount of heat to the room during the defrosting period, so the first defrosting state is performed; when the first defrosting state is performed, it is determined that the current indoor heat exchanger temperature T 内管 and preset temperature value T 预设 , when T is satisfied 内管 ≥T 预设 , indicating that the current indoor heat exchanger temperature is high, the outlet air temperature is more suitable, and can provide more heat. When it is not satisfied, the electric heating is turned on to increase the outlet air temperature and supplement the heat provided to the room.

[0079] When T is not satisfied 设定 -T 内环 ≥ΔT1, further detect the current indoor ambient temperature T 内环 and the current indoor wall temperature T 墙温 The difference 2ΔT2, when T 内环 -T 墙温 When ≥ΔT2, it indicates that although the current indoor ambient temperature is high, the current indoor wall temperature is low, and heat still needs to be supplied to the room, so the second defrosting state is entered. The indoor wall is usually a brick wall structure, which can store heat. When heating, when the wall temperature is low, it will continue to absorb heat from the room. Once the indoor heating stops, the room temperature drops rapidly due to the wall absorbing heat, which further increases the temperature drop during the defrosting period. Therefore, when the indoor wall temperature is significantly different from the indoor ambient temperature, even if the indoor ambient temperature is high or close to the user's set temperature, heat should continue to be supplied to the room to prevent the indoor temperature from dropping sharply due to the wall absorbing heat.

[0080] When T is not satisfied 内环 -T 墙温When ≥ΔT2, it indicates that the current indoor ambient temperature is high, and the wall temperature is also high. The wall has accumulated enough heat, and stops supplying heat to the room during defrosting. The wall does not absorb heat from the room, and the indoor temperature can be maintained stably. All heat is used for defrosting to improve defrosting efficiency. Therefore, the third defrosting method is used in this case.

[0081] The above parameters are explained as follows: T 内环 is the indoor ambient temperature, which is the detection value; T 墙温 is the indoor wall temperature, which is the detection value and can be detected by infrared sensor; T 设定 is the temperature set by the user for the air conditioner; ΔT1 is the preset temperature difference 1, the value range is 0℃~10℃, one of which can be 2℃; ΔT2 is the preset temperature difference 2, the value range is 0℃~15℃, one of which can be 5℃; T 内管 is the indoor heat exchanger temperature, which is the detection value; T 预设 The preset value of the indoor heat exchanger temperature is used to determine whether the electric heater is turned on. The value range is 40℃~60℃, and one of the possible values ​​is 55℃; X is the operating speed of the indoor fan during defrosting, and the value range is 5~1000rpm. In order to ensure that there is enough heat for defrosting, the lowest speed allowed by the fan is usually taken, and one of the possible values ​​is 300rpm.

[0082] The above parameter values ​​are all determined based on experiments, and must meet the requirements of fast defrosting speed, clean defrosting, and small indoor temperature drop during defrosting.

[0083] According to the above parameter values, the defrost control method of the present invention is adopted, and the refrigerant only passes through a part of the indoor heat exchanger or does not pass through the heat exchanger, and most of the heat or all of the heat is used for defrosting, thereby increasing the defrosting speed; during the defrosting period, the heat exchanger does not absorb heat from the room or the room has heat supplement, which reduces the indoor temperature drop. Experimental verification shows that the indoor temperature drop during defrosting is compared between the same set of air conditioners, the "reverse defrosting" method, and the defrosting control method of the present invention as follows:

[0084]

[0085] Among them, the outdoor ambient temperature is a dry bulb temperature of -5°C, a relative humidity of 85%, the air conditioner is set to a heating mode, 25°C, and a high wind speed operation. Compared with reverse defrosting, the defrost control method of the present invention is adopted. During the defrosting period, the indoor temperature drop is reduced by 3.3 to 6.8°C. After the defrosting is completed, the air conditioner can directly blow out hot air, effectively ensuring indoor thermal comfort; at the same time, there is no need to reverse the four-way valve 20, which reduces the probability of failure of the four-way valve 20.

[0086] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0087] In addition to the above, it should be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present invention.

[0088] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0089] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for controlling an air conditioner, the method being used to control the air conditioner, characterized in that: The air conditioner comprises: a compressor (10); an indoor unit, the indoor unit comprising a plurality of indoor heat exchangers, the plurality of indoor heat exchangers comprising a first indoor heat exchanger (101) and a second indoor heat exchanger (102), an exhaust port of the compressor (10) being selectively connected to at least one of the indoor heat exchangers via a four-way valve (20); and an outdoor unit, the outdoor unit comprising an outdoor heat exchanger (30), the outdoor heat exchanger (30) being selectively connected to at least one of the indoor heat exchangers via the four-way valve (20) and a three-way valve body assembly. The control method comprises the following steps: When it is determined that the air conditioner enters the defrost mode, temperature information is acquired, wherein the temperature information at least includes the indoor ambient temperature, the indoor wall temperature and the set temperature of the air conditioner; A control instruction set is generated based on the temperature information, and based on the control instruction set, the air conditioner is controlled to execute a target defrost mode, wherein the target defrost mode includes a plurality of defrost modes. When the difference between the set temperature and the ambient temperature is greater than or equal to a first preset value, a first control instruction in the control instruction set is generated, and the first control instruction is used to control the air conditioner to execute the first defrost mode in the target defrost mode, so that the refrigerant only flows through the first indoor heat exchanger (101), and the second indoor heat exchanger (102) does not work. When it is determined that the difference between the ambient temperature and the wall temperature is greater than or equal to a third preset value, a second control instruction in the control instruction set is generated, and the second control instruction is used to control the air conditioner to execute the second defrost mode in the target defrost mode, so that the refrigerant only flows through the second indoor heat exchanger (102), and the first indoor heat exchanger (101) does not work.

2. The air conditioner control method according to claim 1, characterized in that: The three-way valve body assembly comprises a first three-way valve (61) and a second three-way valve (62), and the heat exchange pipeline of the outdoor unit is connected to the heat exchange pipeline of the indoor unit through the first three-way valve (61) and the second three-way valve (62).

3. The air conditioner control method according to claim 2, characterized in that: The plurality of indoor heat exchangers include: A first indoor heat exchanger (101), wherein an inlet of the first indoor heat exchanger (101) is connected to an outlet of the first three-way valve (61), and an inlet of the first three-way valve (61) is connected to an outlet of the outdoor unit; A second indoor heat exchanger (102), wherein the inlet of the second indoor heat exchanger (102) is connected to the inlet of the first indoor heat exchanger (101), the outlet of the second indoor heat exchanger (102) is connected to the inlet of the second three-way valve (62) via a pipeline, one outlet of the second three-way valve (62) is connected to the four-way valve (20) via a pipeline, and a first connecting branch (103) is provided between the other outlet of the first three-way valve (61) and the other outlet of the second three-way valve (62).

4. The control method of the air conditioner according to claim 3, characterized in that: The air conditioner further comprises a first two-way valve (71), a second two-way valve (72), a third two-way valve (73) and a fourth two-way valve (74); the first two-way valve (71) and the second two-way valve (72) are arranged on a pipeline connecting an outlet of the first indoor heat exchanger (101) and an inlet of the second indoor heat exchanger (102); and the third two-way valve (73) and the fourth two-way valve (74) are arranged on the first connecting branch (103).

5. The air conditioner control method according to claim 4, characterized in that: The air conditioner further comprises a second connecting branch (104), a first end of the second connecting branch (104) being arranged on a pipeline connecting the first two-way valve (71) and the second two-way valve (72), and a second connecting branch (104), a second end of the second connecting branch (104) being arranged on a pipeline connecting the third two-way valve (73) and the fourth two-way valve (74).

6. The control method according to claim 5, characterized in that: The process of controlling the air conditioner to execute the first defrost mode includes: The outdoor fan is controlled to be closed, the throttle valve is controlled to be opened to the maximum opening, the first three-way valve, the second three-way valve and the fourth three-way valve are controlled to be powered off, and the second three-way valve, the first two-way valve and the third two-way valve are controlled to be powered on.

7. The control method according to claim 6, characterized in that: The process of controlling the air conditioner to execute the first defrost mode includes: Collect the temperature of the indoor heat exchanger; When it is determined that the temperature of the indoor heat exchanger is greater than or equal to a second preset value, the first indoor fan is controlled to operate at a first target speed, the first electric heater is controlled to be turned off, the second indoor fan is controlled to be turned off, and the second electric heater is controlled to be turned off; When it is determined that the temperature of the indoor heat exchanger is less than the second preset value, the first indoor fan is controlled to operate at a first target speed, the first electric heater is controlled to be turned on, the second indoor fan is controlled to be turned off, and the second electric heater is controlled to be turned off.

8. The control method according to claim 5, characterized in that: The process of controlling the air conditioner to perform the second defrost mode includes: The outdoor fan is controlled to be turned off, the throttle valve is controlled to be opened to the maximum, the first three-way valve, the second two-way valve and the fourth two-way valve are controlled to be energized, and the second three-way valve, the first two-way valve and the third two-way valve are controlled to be de-energized.

9. The control method according to claim 8, characterized in that: The process of controlling the air conditioner to perform the second defrost mode includes: Collect the temperature of the indoor heat exchanger; When it is determined that the temperature of the indoor heat exchanger is greater than or equal to a second preset value, the first electric heater is controlled to be turned off, the second indoor fan is controlled to be turned off, the second electric heater is controlled to be turned off, the first indoor fan and the first electric heater are controlled to be turned off, the second indoor fan is controlled to operate at the first target speed, and the second electric heater is controlled to be turned off.

10. The control method according to claim 9, characterized in that: The method further comprises: When it is determined that the temperature of the indoor heat exchanger is less than the second preset value, a third control instruction is generated, where the third control instruction is used to control the air conditioner to execute a third defrosting mode.

11. The control method according to claim 10, characterized in that: The process of controlling the air conditioner to execute the third defrost mode includes: Control the outdoor fan to turn off, control the throttle valve to open to the maximum, control the first three-way valve and the second three-way valve to be energized, control the first two-way valve and the second two-way valve to be de-energized, control the third two-way valve and the fourth two-way valve to be energized, control the indoor fan to turn off, control the first heater to turn off, control the second indoor fan to turn off, and control the second electric heater to turn off.

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