Air conditioner, defrosting method of air conditioner and controller of air conditioner

Abstract

The invention discloses an air conditioner, a defrosting method of the air conditioner and a controller of the air conditioner, the air conditioner is provided with a bypass pipeline, an outdoor heat exchanger is divided into a plurality of sub heat exchangers, one end of the bypass pipeline is connected with an exhaust port of a compressor through a refrigerant main path, and the other end of the bypass pipeline is divided into a plurality of refrigerant branch paths correspondingly connected with the sub heat exchangers; under the defrosting working condition, by controlling the first throttling assembly in the bypass pipeline and selecting the different sub heat exchangers to communicate with the exhaust port of the compressor, all the sub heat exchangers can be defrosted in sequence, so that the defrosting area of the air conditioner in the defrosting process is reduced, and the defrosting efficiency of the air conditioner is improved. The method is beneficial for the compressor to build the exhaust pressure, so that the operation power of the compressor is improved, more defrosting heat can be supplied, the defrosting time is finally shortened, and efficient and rapid defrosting is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioner defrosting, and in particular to an air conditioner, a defrosting method for the air conditioner, and a controller thereof. Background Art

[0002] When the outdoor temperature is low and the air conditioner is heating, the temperature of the outdoor heat exchanger of the air conditioner will drop below 0 degrees. Long-term operation will cause the moisture in the air to condense into frost on the outdoor evaporator, affecting the normal heating of the air conditioner. Therefore, under heating conditions, the air conditioner needs to defrost the outdoor heat exchanger regularly.

[0003] In the related art, the air conditioner can execute a refrigeration cycle to heat the outdoor heat exchanger to achieve defrosting, or an electric heater can be installed at the outdoor heat exchanger to heat and defrost, or a heat storage module can be installed to use heat for defrosting, etc.; no matter which solution is used, it will affect the normal heating of the room and easily cause discomfort to the user, so the duration of the defrosting process should be shortened as much as possible. Summary of the invention

[0004] The embodiments of the present application provide an air conditioner, a defrosting method for the air conditioner, and a controller thereof, which can shorten the duration of the defrosting process.

[0005] In a first aspect, an embodiment of the present application provides an air conditioner, comprising a compressor, an outdoor heat exchanger and an indoor heat exchanger, wherein the outdoor heat exchanger comprises a plurality of sub-heat exchangers connected in parallel with each other, and the air conditioner further comprises:

[0006] A bypass pipeline, wherein the bypass pipeline is provided with a first throttling assembly, the bypass pipeline comprises a refrigerant main pipeline and a plurality of refrigerant branches connected to the refrigerant main pipeline, the refrigerant main pipeline is connected to the exhaust port of the compressor, the refrigerant branches correspond to the sub-heat exchangers one by one, and are connected to the pipeline between the corresponding sub-heat exchanger and the indoor heat exchanger;

[0007] The controller is used to control the throttling component to connect the exhaust port of the compressor to the refrigerant branch corresponding to the sub-heat exchanger under the defrosting condition, so as to defrost the sub-heat exchanger in turn.

[0008] In some embodiments, the first throttling assembly includes a first solenoid valve and a first capillary tube, and the first solenoid valve and the first capillary tube are connected in series;

[0009] Each of the refrigerant branches is provided with the first solenoid valve and the first capillary tube;

[0010] Alternatively, the refrigerant main circuit is provided with the first capillary tube, and each of the refrigerant branch circuits is provided with the first solenoid valve.

[0011] In some embodiments, the first throttling component includes a plurality of first electronic expansion valves, and each of the refrigerant branches is provided with the first electronic expansion valve.

[0012] In some embodiments, the first throttling assembly includes a first electronic expansion valve, a first solenoid valve and a first capillary tube, and the first solenoid valve and the first capillary tube are connected in series;

[0013] A portion of the refrigerant branch is provided with the first electronic expansion valve, and another portion of the refrigerant branch is provided with the first solenoid valve and the first capillary tube.

[0014] In some embodiments, a pipeline switching assembly is provided between the refrigerant main circuit and the refrigerant main circuit, and the controller is also used to control the first throttling assembly and the pipeline switching assembly under defrost conditions, connecting the exhaust port of the compressor to the refrigerant branch corresponding to the sub-heat exchanger to defrost the sub-heat exchanger in turn.

[0015] In some embodiments, the first throttling assembly includes a second solenoid valve and a second capillary tube, and the first solenoid valve and the first capillary tube are connected in series;

[0016] The refrigerant main circuit is provided with the second solenoid valve, and each of the refrigerant branch circuits is provided with the second capillary tube;

[0017] Alternatively, the refrigerant main circuit is provided with the second capillary tube, and each of the refrigerant branch circuits is provided with the second solenoid valve;

[0018] Alternatively, the refrigerant main circuit is provided with the second solenoid valve and the second capillary tube;

[0019] Alternatively, a portion of the refrigerant branch is provided with the second solenoid valve and the second capillary tube, and another portion of the refrigerant branch is provided with the second capillary tube.

[0020] In some embodiments, the first throttling assembly includes a second electronic expansion valve and a second capillary tube;

[0021] The second electronic expansion valve is arranged on the refrigerant main circuit;

[0022] Alternatively, a portion of the refrigerant branch is provided with the second electronic expansion valve, and another portion of the refrigerant branch is provided with the second capillary tube.

[0023] In some embodiments, the air conditioner further includes a plurality of second throttling components, each of which corresponds to the sub-heat exchanger one by one and is arranged in a pipeline between the corresponding sub-heat exchanger and the indoor heat exchanger.

[0024] In some embodiments, the second throttling component is an electronic expansion valve or a capillary tube.

[0025] In a second aspect, an embodiment of the present application further provides a defrosting method for an air conditioner, which is applied to the air conditioner described in the first aspect, and the defrosting method comprises:

[0026] Under the defrosting condition, the throttling component is controlled to connect the exhaust port of the compressor to the refrigerant branch corresponding to the sub-heat exchanger, so as to defrost the sub-heat exchanger in turn.

[0027] In some embodiments, controlling the throttling assembly to connect the exhaust port of the compressor to the refrigerant branch corresponding to the sub-heat exchanger to defrost the sub-heat exchanger in sequence includes:

[0028] Controlling the air conditioner to enter a heating cycle;

[0029] Determine a first target sub-heat exchanger that needs to be defrosted, control the throttling component to connect the refrigerant branch from the exhaust port of the compressor to the first target sub-heat exchanger, and shut off the refrigerant branch from the exhaust port of the compressor to other sub-heat exchangers;

[0030] After the first target sub-heat exchanger completes defrosting, another sub-heat exchanger that needs to be defrosted is selected as the first target sub-heat exchanger for defrosting.

[0031] In some embodiments, after controlling the air conditioner to enter a heating cycle, the defrosting method further includes:

[0032] When the exhaust temperature of the compressor is lower than a preset exhaust temperature, gradually increasing the operating frequency of the compressor;

[0033] In the process of gradually increasing the operating frequency of the compressor, when at least one of the following conditions is met, the increasing of the operating frequency of the compressor is stopped:

[0034] The exhaust temperature of the compressor reaches the preset exhaust temperature;

[0035] The operating frequency of the compressor reaches a preset operating frequency threshold;

[0036] The exhaust pressure of the compressor reaches a preset exhaust pressure threshold.

[0037] In some embodiments, gradually increasing the operating frequency of the compressor includes:

[0038] The operating frequency of the compressor is increased according to a preset time interval and a preset frequency step.

[0039] In some embodiments, the first throttling component includes a target electronic expansion valve, and the target electronic expansion valve is connected in series with the first target sub-heat exchanger; after controlling the air conditioner to enter a heating cycle, the defrosting method further includes:

[0040] When the exhaust temperature of the compressor is lower than the preset exhaust temperature, gradually increasing the operating frequency of the compressor and gradually reducing the opening of the target electronic expansion valve;

[0041] In the process of gradually increasing the operating frequency of the compressor and gradually decreasing the opening of the target electronic expansion valve, when the exhaust temperature of the compressor reaches the preset exhaust temperature, or the exhaust pressure of the compressor reaches the preset exhaust pressure threshold, stop increasing the operating frequency of the compressor and stop decreasing the opening of the target electronic expansion valve; when the opening of the target electronic expansion valve is closed to the preset opening threshold, stop decreasing the opening of the target electronic expansion valve; when the operating frequency of the compressor reaches the preset operating frequency threshold, stop increasing the operating frequency of the compressor.

[0042] In some embodiments, the defrosting method further comprises:

[0043] In the defrosting condition, when the indoor ambient temperature is higher than the preset temperature value, the throttling component is controlled to shut off the refrigerant branch corresponding to the exhaust port of the compressor to the sub-heat exchanger, and the sub-heat exchanger is defrosted in sequence according to the refrigeration cycle of the air conditioner;

[0044] In the defrosting condition, when the indoor ambient temperature is lower than the preset temperature value, the throttling component is controlled to connect the exhaust port of the compressor to the refrigerant branch corresponding to the sub-heat exchanger to defrost the sub-heat exchanger in turn.

[0045] In some embodiments, the air conditioner further comprises a plurality of second throttling components, each of the second throttling components corresponds to the sub-heat exchanger one by one and is arranged in a pipeline between the corresponding sub-heat exchanger and the indoor heat exchanger; the defrosting of the sub-heat exchanger according to the refrigeration cycle of the air conditioner comprises:

[0046] Determine a second target sub-heat exchanger that needs to be defrosted, turn on the second throttling component corresponding to the second target sub-heat exchanger, and turn off the second throttling components corresponding to the other sub-heat exchangers;

[0047] After the second target sub-heat exchanger completes defrosting, another sub-heat exchanger that needs to be defrosted is selected as the second target sub-heat exchanger for defrosting.

[0048] In a third aspect, an embodiment of the present application provides a controller comprising at least one processor and a memory for communicating with the at least one processor; the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the defrost method for the air conditioner as described in the embodiment of the second aspect.

[0049] The air conditioner, the defrosting method of the air conditioner and the controller thereof of the embodiments of the present application have at least the following beneficial effects: the air conditioner is provided with a bypass pipeline and divides the outdoor heat exchanger into multiple sub-heat exchangers, one end of the bypass pipeline is connected to the exhaust port of the compressor through the refrigerant main circuit, and the other end is divided into multiple refrigerant branches correspondingly connected to each sub-heat exchanger, thereby forming a refrigerant flow path from the exhaust port of the compressor to each sub-heat exchanger. Under the defrosting condition, by controlling the first throttling component in the bypass pipeline, different sub-heat exchangers can be selected to connect to the exhaust port of the compressor, so that each sub-heat exchanger can be defrosted in turn, that is, defrosting is performed on one or a part of the sub-heat exchangers each time, and after defrosting is completed, it is switched to another or another part of the sub-heat exchangers for defrosting. Compared with the scheme of defrosting the entire outdoor heat exchanger, the sub-heat exchanger area of ​​the present application is small, so the defrosting area of ​​the air conditioner becomes smaller, which is beneficial for the compressor to establish exhaust pressure, thereby improving the operating power of the compressor, and being able to supply more defrosting heat, ultimately reducing the defrosting time, and achieving efficient and fast defrosting.

[0050] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures specifically pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a schematic diagram of the structure of an air conditioner provided in an embodiment of the present application;

[0052] Figure 2 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0053] Figure 3 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0054] Figure 4 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0055] Figure 5 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0056] Figure 6is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0057] Figure 7 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0058] Figure 8 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0059] Fig. 9 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0060] Fig.10 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0061] Fig.11 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0062] Fig.12 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0063] Fig.13 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0064] Fig.14 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0065] Fig.15 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0066] Fig.16 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0067] Fig.17 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0068] Fig.18 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0069] Fig.19 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0070] Fig. 20 is a schematic diagram of the architecture of another air conditioner provided in an embodiment of the present application;

[0071] Fig.21 is an overall flow chart of the defrosting method for an air conditioner provided in an embodiment of the present application;

[0072] Fig. 22This is a flow chart of defrosting the sub-heat exchangers in sequence during hot gas bypass defrosting provided by an embodiment of the present application;

[0073] Fig.23 is a flow chart of the operating frequency control of the compressor during hot gas bypass defrosting provided by an embodiment of the present application;

[0074] Fig.24 is a control flow chart of the operating frequency of the compressor and the opening degree of the electronic expansion valve during hot gas bypass defrosting provided by an embodiment of the present application;

[0075] Fig.25 is a flow chart of determining a defrosting method according to an indoor ambient temperature provided by an embodiment of the present application;

[0076] Fig.26 This is a flow chart of defrosting the sub-heat exchangers in sequence during reverse cycle defrosting provided in an embodiment of the present application. DETAILED DESCRIPTION

[0077] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. In addition, the characteristics, operations or features described in the specification can be combined in any appropriate manner to form various implementation methods. At the same time, the steps or actions in the method description can also be replaced or adjusted in order in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the accompanying drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a necessary sequence, unless otherwise specified that a certain sequence must be followed.

[0078] In the description of this application, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0079] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0080] The common defrosting methods include the following:

[0081] 1. Reverse refrigeration and defrosting

[0082] Reverse refrigeration defrosting is one of the most common defrosting methods for air conditioners. The system structure and defrosting method are relatively simple. A four-way valve is added to the refrigeration system. When the control system detects that the defrosting conditions are met, the four-way valve switches from the heating state to the cooling state. The outdoor heat exchanger is in the heat dissipation state, and the hot gas from the refrigerant is used to defrost the outdoor heat exchanger.

[0083] The defrost process is as follows: when the control system detects that the defrost conditions are met, it controls the compressor to reduce frequency or stop, the indoor and outdoor fans stop running, the four-way valve solenoid valve is actuated, and the state is switched to cooling. After that, the compressor runs, allowing the high-temperature refrigerant to enter the outdoor heat exchanger, and defrosting begins. When it is detected that the defrost end conditions are met, the compressor is controlled to reduce frequency or stop, the four-way valve solenoid valve is actuated, and the state is switched to heating. After that, the compressor restarts, the indoor and outdoor fans start, and the defrost ends.

[0084] 2. Electric defrosting

[0085] Electric defrosting is to install electric heating devices in the outdoor heat exchanger and connect it to the control system. It is simple and easy to implement, but it is not economical from the perspective of energy consumption. Therefore, electric heating is usually used as a supplement to reverse refrigeration defrosting. However, for some equipment without reverse defrosting function, electric defrosting is a simple and easy method.

[0086] The defrost process is as follows: when the control system detects that the defrost conditions are met, it controls the compressor to stop, the indoor fan and the outdoor fan to stop running, and the electric heater to power on; when it detects that the defrost end conditions are met, the electric heater is powered off, and then the compressor, indoor fan and outdoor fan are started, and the defrost ends.

[0087] 3. Heat storage defrosting

[0088] Thermal storage defrosting is to add a thermal storage module to the refrigeration system, collect the waste heat generated by the machine operation through the thermal storage module, and then use this part of the heat when defrosting is needed. Generally, the thermal storage module is attached to the compressor housing to absorb the heat generated during the operation of the compressor.

[0089] From the perspective of energy consumption, heat storage defrosting has low energy consumption and good economy. It is one of the defrosting methods that has developed rapidly in recent years. However, the refrigeration system is relatively complex, the control technology is difficult, and the cost is high. It is usually only seen on high-end equipment.

[0090] In the above-mentioned reverse cooling defrosting, the indoor unit not only does not heat, but also needs to absorb heat in the room. For users who need heating, the experience effect is relatively poor. Therefore, in recent years, a hot air bypass defrosting solution has been proposed in air conditioners to supplement the shortcomings of reverse cooling defrosting. It can defrost without absorbing heat or even providing heat to the room.

[0091] The hot gas bypass defrosting process is as follows: when the control system detects that the defrosting conditions are met, the outdoor fan stops and the bypass valve opens for defrosting. When it detects that the defrosting end conditions are met, the bypass valve closes, the outdoor fan is turned on, and the defrosting ends.

[0092] From the above, it can be seen that no matter which method is used for defrosting, the indoor unit fan cannot operate. This results in the inability to heat the room normally. Generally speaking, the defrosting process takes 10-15 minutes to complete. During this period, the indoor heating will be suspended and the temperature will drop suddenly, which will bring a very bad experience to indoor users. Therefore, the length of defrosting time is a very core parameter that directly affects the indoor user experience. This application will focus on how to shorten the defrosting time and propose a series of efficient and fast defrosting solutions.

[0093] Based on this, an embodiment of the present application provides an air conditioner, a defrosting method for an air conditioner and a controller thereof. The air conditioner is provided with a bypass pipe and divides an outdoor heat exchanger into multiple sub-heat exchangers. One end of the bypass pipe is connected to the exhaust port of the compressor through a refrigerant main circuit, and the other end is divided into multiple refrigerant branches correspondingly connected to each sub-heat exchanger, thereby forming a refrigerant flow path from the exhaust port of the compressor to each sub-heat exchanger. Under the defrosting condition, by controlling the first throttling component in the bypass pipe, different sub-heat exchangers can be selected to connect to the exhaust port of the compressor, so that each sub-heat exchanger can be defrosted in turn. That is to say, defrosting is performed on one or a part of the sub-heat exchangers each time, and after defrosting is completed, it is switched to another or another part of the sub-heat exchangers for defrosting. Compared with the scheme of defrosting the entire outdoor heat exchanger, the sub-heat exchanger area of ​​the present application is small, so the defrosting area of ​​the air conditioner becomes smaller, which is beneficial for the compressor to establish exhaust pressure, thereby improving the operating power of the compressor, and being able to supply more defrosting heat, ultimately reducing the defrosting time, and achieving efficient and fast defrosting.

[0094] The air conditioner, the defrosting method of the air conditioner and the controller thereof are described below in conjunction with the accompanying drawings:

[0095] Reference Figure 1 As shown, an air conditioner provided in an embodiment of the present application includes a compressor 100, an outdoor heat exchanger and an indoor heat exchanger 300, wherein the outdoor heat exchanger includes a plurality of sub-heat exchangers connected in parallel, and the air conditioner further includes:

[0096] A bypass pipeline, wherein the bypass pipeline is provided with a first throttling assembly, and the bypass pipeline includes a refrigerant main pipeline and a plurality of refrigerant branches connected to the refrigerant main pipeline, wherein the refrigerant main pipeline is connected to the exhaust port of the compressor 100, and the refrigerant branches correspond to the sub-heat exchangers one by one and are connected to the pipeline between the corresponding sub-heat exchanger and the indoor heat exchanger 300;

[0097] The controller is used to control the first throttling component to connect the exhaust port of the compressor 100 to the refrigerant branch corresponding to the sub-heat exchanger under the defrosting condition, so as to defrost the sub-heat exchangers in turn.

[0098] The refrigerant circulation system of a conventional air conditioner is usually composed of a compressor 100, a four-way valve 400, an outdoor heat exchanger, an expansion valve and an indoor heat exchanger 300. The exhaust port of the compressor 100 is connected to the four-way valve 400. According to one valve state of the four-way valve 400, the exhaust port of the compressor 100 can be connected to the outdoor heat exchanger, the expansion valve, the indoor heat exchanger 300 and then return to the air intake port of the compressor 100 through the four-way valve 400, at which time a refrigeration cycle for the indoor room is realized; according to another valve state of the four-way valve 400, the exhaust port of the compressor 100 can also be connected to the indoor heat exchanger 300, the expansion valve, the outdoor heat exchanger and then return to the air intake port of the compressor 100 through the four-way valve 400, at which time a heating cycle for the indoor room is realized. Based on this refrigerant circulation system, the embodiment of the present application designs the outdoor heat exchanger into a plurality of separated sub-heat exchangers, and also adds a bypass pipeline to the sub-heat exchanger at the exhaust port of the compressor 100, so as to reduce the heat exchanger area for each defrost under defrost conditions, improve the defrost capacity of the compressor 100, and realize hot gas bypass defrost through the bypass pipeline.

[0099] Among them, multiple sub-heat exchangers are connected in parallel, and each sub-heat exchanger is connected to the four-way valve 400 at one end, and is connected to the indoor heat exchanger 300 at the other end (through the expansion valve). Under the cooling condition of the air conditioner, the high-temperature and high-pressure refrigerant discharged from the exhaust port of the compressor 100 enters the various sub-heat exchangers of the outdoor heat exchanger, and each sub-heat exchanger performs heat exchange with the outdoor environment. At this time, the total heat exchange area of ​​all sub-heat exchangers is equivalent to the heat exchange area of ​​an entire outdoor heat exchanger; under the heating condition of the air conditioner, the high-temperature and high-pressure refrigerant discharged from the exhaust port of the compressor 100 enters the indoor heat exchanger 300, and the refrigerant enters the various sub-heat exchangers of the outdoor heat exchanger after heat exchange (through the expansion valve) through the indoor heat exchanger 300. Each sub-heat exchanger performs heat exchange with the outdoor environment. At this time, the total heat exchange area of ​​all sub-heat exchangers is equivalent to the heat exchange area of ​​an entire outdoor heat exchanger.

[0100] The bypass pipeline is composed of a refrigerant main line and a refrigerant branch line. The refrigerant main line is connected to the exhaust port of the compressor 100 and is used to receive the high-temperature and high-pressure refrigerant discharged by the compressor 100. The refrigerant branch line is equivalent to a bifurcated pipeline of the refrigerant main line. Each refrigerant branch line corresponds to a sub-heat exchanger and is connected to the pipeline between the corresponding sub-heat exchanger and the indoor heat exchanger 300. In this way, a refrigerant pipeline from the exhaust port of the compressor 100 to the refrigerant branch of each sub-heat exchanger is formed. By controlling the exhaust port of the compressor 100 to be connected to different refrigerant branches through the first throttling component, the sub-heat exchangers can be defrosted in sequence. Specifically, in the defrosting condition of the air conditioner, the controller controls the first throttling component to connect the bypass line, so that the exhaust port of the compressor 100 is connected to the refrigerant branch where the sub-heat exchanger is located through the bypass line, and one or part of the sub-heat exchangers can be selected through the first throttling component, so that the high-temperature and high-pressure refrigerant will flow into one or part of the selected sub-heat exchangers, so as to perform centralized defrosting on one or part of the selected sub-heat exchangers, and after completing the defrosting of this part, another or another part of the sub-heat exchangers will be selected for defrosting. Therefore, the entire defrosting process is manifested as defrosting one or part of the sub-heat exchangers each time, and when the defrosting of all the sub-heat exchangers that need to be defrosted is completed, the entire defrosting process is completed.

[0101] In the above-mentioned defrosting process, since each sub-heat exchanger can be defrosted in turn and the area of ​​the sub-heat exchanger is small, the defrost area of ​​the air conditioner becomes smaller, which is beneficial for the compressor 100 to establish exhaust pressure. The greater the exhaust pressure, the greater the power of the compressor 100, thereby increasing the operating power of the compressor 100, being able to supply more defrosting heat, and ultimately reducing the defrosting time, achieving efficient and rapid defrosting.

[0102] It is understandable that the first throttling assembly can have a variety of different structures, such as a first throttling assembly composed of an electronic expansion valve, which controls the opening of the electronic expansion valve to realize the on-off of the refrigerant pipeline, thereby realizing the selection of the refrigerant branch of the sub-heat exchanger, etc. The specific structure of the first throttling assembly is described below through a variety of different embodiments.

[0103] In some embodiments, the first throttling assembly includes a first solenoid valve and a first capillary tube, and the first solenoid valve and the first capillary tube are connected in series;

[0104] Each refrigerant branch is provided with a first solenoid valve and a first capillary tube;

[0105] Alternatively, the refrigerant main circuit is provided with a first capillary tube, and each refrigerant branch circuit is provided with a first solenoid valve.

[0106] The above two situations refer to Figure 1 and Figure 2 shown.

[0107] The first case refers to Figure 1 As shown, an air conditioner having two sub-heat exchangers is used as an example for explanation, the outdoor heat exchanger is divided into a first sub-heat exchanger 210 and a second sub-heat exchanger 220, the first sub-heat exchanger 210 and the second sub-heat exchanger 220 are connected in parallel, and are respectively provided with a first refrigerant branch and a second refrigerant branch, the bypass pipeline can connect the refrigerant main line and the two refrigerant branches through a Y-shaped pipe, and a first solenoid valve and a first capillary tube are provided in the first refrigerant branch and the second refrigerant branch. For easy distinction, the first solenoid valve in the first refrigerant branch is marked as solenoid valve 11, the first capillary tube in the first refrigerant branch is marked as capillary tube 12, the first solenoid valve in the second refrigerant branch is marked as solenoid valve 13, and the first capillary tube in the second refrigerant branch is marked as solenoid valve 14. Recorded as capillary 14; at this time, under the defrosting condition, if the hot gas bypass method is used to defrost the first sub-heat exchanger 210 and the second sub-heat exchanger 220 in turn, the compressor 100 operates normally, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan stops, the solenoid valve 11 is opened, and the solenoid valve 13 is closed, so as to first concentrate heat to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the solenoid valve 13 is opened, the solenoid valve 11 is closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the solenoid valve 13 is closed, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0108] The second case refers to Figure 2 As shown, an air conditioner having two sub-heat exchangers is used as an example for explanation, the outdoor heat exchanger is divided into a first sub-heat exchanger 210 and a second sub-heat exchanger 220, the first sub-heat exchanger 210 and the second sub-heat exchanger 220 are connected in parallel, and are respectively provided with a first refrigerant branch and a second refrigerant branch, the bypass pipeline can connect the refrigerant main circuit and the two refrigerant branches through a Y-shaped pipe, a first solenoid valve is provided in both the first refrigerant branch and the second refrigerant branch, and a first capillary tube is provided in the refrigerant main circuit. For the convenience of distinction, the first solenoid valve in the first refrigerant branch is recorded as a solenoid valve 21, the first solenoid valve in the second refrigerant branch is recorded as a solenoid valve 22, and the first capillary tube in the refrigerant main circuit is recorded as a capillary tube 23; At this time, under the defrosting condition, if the hot gas bypass method is used to defrost the first sub-heat exchanger 210 and the second sub-heat exchanger 220 in turn, the compressor 100 operates normally, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan stops, the solenoid valve 11 is opened, and the solenoid valve 13 is closed, so as to first concentrate heat to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the solenoid valve 13 is opened, the solenoid valve 11 is closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the solenoid valve 13 is closed, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0109] In some embodiments, the first throttling assembly includes a plurality of first electronic expansion valves, and each refrigerant branch is provided with a first electronic expansion valve.

[0110] The above situation refers to Figure 3 As shown, an air conditioner with two sub-heat exchangers is used as an example for explanation. The outdoor heat exchanger is divided into a first sub-heat exchanger 210 and a second sub-heat exchanger 220. The first sub-heat exchanger 210 and the second sub-heat exchanger 220 are connected in parallel, and are respectively provided with a first refrigerant branch and a second refrigerant branch. The bypass pipeline can connect the refrigerant main line and the two refrigerant branches through a Y-shaped pipe. A first electronic expansion valve is provided in the first refrigerant branch and the second refrigerant branch. For easy distinction, the first electronic expansion valve in the first refrigerant branch is recorded as electronic expansion valve 31, and the first electronic expansion valve in the second refrigerant branch is recorded as electronic expansion valve 32. At this time, under the defrosting condition, if the hot gas bypass method is adopted, the first sub-heat exchanger 210 and the second sub-heat exchanger 220 are sequentially closed. When the heat exchanger 220 is defrosted, the compressor 100 operates normally, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan stops, the electronic expansion valve 31 is controlled to be at a certain opening or automatically adjusted to a suitable opening in real time, and the electronic expansion valve 32 is closed, so as to first concentrate heat to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the electronic expansion valve 31 is closed, the electronic expansion valve 32 is controlled to be at a certain opening or automatically adjusted to a suitable opening in real time, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the electronic expansion valve 32 is closed, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0111] In some embodiments, the first throttling component includes a first electronic expansion valve, a first solenoid valve and a first capillary tube, and the first solenoid valve and the first capillary tube are connected in series; a portion of the refrigerant branch is provided with the first electronic expansion valve, and another portion of the refrigerant branch is provided with the first solenoid valve and the first capillary tube.

[0112] The above situation refers to Figure 4As shown, an air conditioner having two sub-heat exchangers is used as an example for explanation, the outdoor heat exchanger is divided into a first sub-heat exchanger 210 and a second sub-heat exchanger 220, the first sub-heat exchanger 210 and the second sub-heat exchanger 220 are connected in parallel, and are respectively provided with a first refrigerant branch and a second refrigerant branch, the bypass pipeline can connect the refrigerant main line and the two refrigerant branches through a Y-shaped pipe, a first solenoid valve and a first capillary tube are provided in the first refrigerant branch, and a first electronic expansion valve is provided in the second refrigerant branch. For the convenience of distinction, the first solenoid valve in the first refrigerant branch is recorded as a solenoid valve 41, the first capillary tube in the first refrigerant branch is recorded as a capillary tube 42, and the first electronic expansion valve in the second refrigerant branch is recorded as an electronic expansion valve 43; at this time, under the defrosting condition, If the hot gas bypass method is used to defrost the first sub-heat exchanger 210 and the second sub-heat exchanger 220 in turn, the compressor 100 operates normally, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan stops, the solenoid valve 41 is opened, and the electronic expansion valve 43 is closed, so as to concentrate heat to defrost the first sub-heat exchanger 210 first. When the frost on the first sub-heat exchanger 210 is completely removed, the solenoid valve 41 is closed, and the electronic expansion valve 43 is controlled to be at a certain opening or automatically adjusted to a suitable opening in real time, so as to concentrate heat to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the electronic expansion valve 43 is closed, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0113] In some embodiments, a pipeline switching assembly 500 is provided between the refrigerant main circuit and the refrigerant main circuit, and the controller is also used to control the first throttling assembly and the pipeline switching assembly 500 under the defrost condition, connecting the exhaust port of the compressor 100 to the refrigerant branch corresponding to the sub-heat exchanger to defrost the sub-heat exchanger in turn.

[0114] The pipeline switching component 500 can be controlled based on its own structure to connect the main refrigerant circuit to which refrigerant branch or branches, and the switching of the refrigerant branches can be achieved based on electric control. For example, the pipeline switching component 500 is a three-way valve. For the case where there are only two sub-heat exchangers, the main refrigerant circuit can only be connected to the refrigerant branch of one of the sub-heat exchangers at any time. The pipeline switching component 500 can also be other one-to-many port control components, such as providing an independent control valve for each refrigerant branch, etc. The structural forms of the pipeline switching component 500 are not exemplified one by one here. With the addition of the pipeline switching component 500, the air conditioner needs to increase the control of the pipeline switching component 500 when the hot gas bypass defrosts. Therefore, the controller simultaneously controls the first throttling component and the pipeline switching component 500 to connect the bypass pipeline, so that the exhaust port of the compressor 100 is connected to the refrigerant branch where the sub-heat exchanger is located through the bypass pipeline, and one or part of the sub-heat exchangers can be selected through the first throttling component and the pipeline switching component 500, so that the high-temperature and high-pressure refrigerant will flow into one or part of the selected sub-heat exchangers, so as to perform centralized defrosting on one or part of the selected sub-heat exchangers, and after completing this part of defrosting, another or another part of the sub-heat exchangers will be selected for defrosting. Therefore, the entire defrosting process is manifested as defrosting one or part of the sub-heat exchangers each time, and when the defrosting of all the sub-heat exchangers that need to be defrosted is completed, the entire defrosting process is completed.

[0115] Based on the system architecture of the pipeline switching component 500, the first throttling component of the present application can have a variety of different structures. The specific structure of the first throttling component is described below through a variety of different embodiments.

[0116] In some embodiments, the first throttling assembly includes a second solenoid valve and a second capillary tube, and the first solenoid valve and the first capillary tube are connected in series;

[0117] The refrigerant main circuit is provided with a second solenoid valve, and each refrigerant branch circuit is provided with a second capillary tube;

[0118] Alternatively, the refrigerant main circuit is provided with a second capillary tube, and each refrigerant branch circuit is provided with a second solenoid valve;

[0119] Alternatively, the refrigerant main circuit is provided with a second solenoid valve and a second capillary tube;

[0120] Alternatively, a portion of the refrigerant branch is provided with a second solenoid valve and a second capillary tube, and another portion of the refrigerant branch is provided with a second capillary tube.

[0121] The above two situations refer to Figures 5 to 8 shown.

[0122] The first case refers to Figure 5As shown, an air conditioner having two sub-heat exchangers is used as an example for explanation. The outdoor heat exchanger is divided into a first sub-heat exchanger 210 and a second sub-heat exchanger 220. The first sub-heat exchanger 210 and the second sub-heat exchanger 220 are connected in parallel, and are respectively provided with a first refrigerant branch and a second refrigerant branch. The management switching component is a three-way valve, one end of the three-way valve is connected to the refrigerant main circuit, and the remaining two ends are respectively connected to the first refrigerant branch and the second refrigerant branch. A second solenoid valve is provided in the refrigerant main circuit, and a second capillary is provided in the first refrigerant branch and the second refrigerant branch. For the convenience of distinction, the second solenoid valve in the refrigerant main circuit is recorded as solenoid valve 51, the second capillary in the first refrigerant branch is recorded as capillary 52, and the second capillary in the second refrigerant branch is recorded as capillary 53. At this time, under the defrosting condition, if hot gas bypass is used The first sub-heat exchanger 210 and the second sub-heat exchanger 220 are defrosted in turn in this manner, the compressor 100 operates normally, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan stops, the solenoid valve 51 is opened, and the pipeline switching component 500 is in a power-off state (the main refrigerant path is connected to the first refrigerant branch), so as to first concentrate heat to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the pipeline switching component 500 is in a power-on state (the main refrigerant path is connected to the second refrigerant branch), and concentrate heat to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the solenoid valve 51 is closed, the pipeline switching component 500 is in a power-off state, and then the indoor fan is turned on, and the air conditioner operates in a normal heating mode.

[0123] The second case refers to Figure 6As shown, an air conditioner having two sub-heat exchangers is used as an example for explanation, the outdoor heat exchanger is divided into a first sub-heat exchanger 210 and a second sub-heat exchanger 220, the first sub-heat exchanger 210 and the second sub-heat exchanger 220 are connected in parallel, and are respectively provided with a first refrigerant branch and a second refrigerant branch, the management switching component is a three-way valve, one end of the three-way valve is connected to the refrigerant main circuit, and the remaining two ends are respectively connected to the first refrigerant branch and the second refrigerant branch, a second capillary tube is provided in the refrigerant main circuit, and a second solenoid valve is provided in the first refrigerant branch and the second refrigerant branch, for the convenience of distinction, the second capillary tube in the refrigerant main circuit is recorded as capillary tube 61, the second solenoid valve in the first refrigerant branch is recorded as solenoid valve 62, and the second solenoid valve in the second refrigerant branch is recorded as solenoid valve 63; at this time, under the defrosting condition, if the hot gas bypass method is adopted, the first sub-heat exchanger 2 10 and the second sub-heat exchanger 220 are defrosted, the compressor 100 operates normally, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan stops, the pipeline switching component 500 is in a power-off state (the main refrigerant path is connected to the first refrigerant branch), the solenoid valve 62 is opened, and the solenoid valve 63 is closed, so as to first concentrate heat to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the pipeline switching component 500 is in a power-on state (the main refrigerant path is connected to the second refrigerant branch), the solenoid valve 62 is closed, and the solenoid valve 63 is opened to concentrate heat to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the solenoid valve 63 is closed, the pipeline switching component 500 is in a power-off state, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0124] The third case refers to Figure 7As shown, an air conditioner having two sub-heat exchangers is used as an example for explanation, the outdoor heat exchanger is divided into a first sub-heat exchanger 210 and a second sub-heat exchanger 220, the first sub-heat exchanger 210 and the second sub-heat exchanger 220 are connected in parallel, and are respectively provided with a first refrigerant branch and a second refrigerant branch, the management switching component is a three-way valve, one end of the three-way valve is connected to the refrigerant main circuit, and the remaining two ends are respectively connected to the first refrigerant branch and the second refrigerant branch, a second solenoid valve and a second capillary tube are provided in the refrigerant main circuit, for easy distinction, the second solenoid valve in the refrigerant main circuit is recorded as solenoid valve 71, and the second capillary tube in the refrigerant main circuit is recorded as capillary tube 72; at this time, under the defrosting condition, if the hot gas bypass method is adopted, the first sub-heat exchanger 210 and the second sub-heat exchanger are sequentially 220 is defrosted, the compressor 100 operates normally, the four-way valve 400 is switched to the valve state of the heating cycle, the indoor fan stops, the pipeline switching component 500 is in a power-off state (the main refrigerant path is connected to the first refrigerant branch), and the solenoid valve 71 is opened to concentrate heat to defrost the first sub-heat exchanger 210 first. When the frost on the first sub-heat exchanger 210 is completely removed, the pipeline switching component 500 is in a power-on state (the main refrigerant path is connected to the second refrigerant branch), and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the solenoid valve 71 is closed, the pipeline switching component 500 is in a power-off state, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0125] The fourth case refers to Figure 8As shown, an air conditioner with two sub-heat exchangers is used as an example for explanation. The outdoor heat exchanger is divided into a first sub-heat exchanger 210 and a second sub-heat exchanger 220. The first sub-heat exchanger 210 and the second sub-heat exchanger 220 are connected in parallel, and are respectively provided with a first refrigerant branch and a second refrigerant branch. The management switching component is a three-way valve, one end of the three-way valve is connected to the refrigerant main circuit, and the remaining two ends are respectively connected to the first refrigerant branch and the second refrigerant branch. A second capillary is provided in the first refrigerant branch and the second refrigerant branch, and a first solenoid valve is also provided in the first refrigerant branch. For ease of distinction, the second capillary in the first refrigerant branch is recorded as capillary 81, the second capillary in the second refrigerant branch is recorded as capillary 82, and the second solenoid valve in the first refrigerant branch is recorded as solenoid valve 83; at this time, under the defrosting condition, if the heat is used The air bypass method defrosts the first sub-heat exchanger 210 and the second sub-heat exchanger 220 in turn, the compressor 100 operates normally, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan stops, the pipeline switching component 500 is in a power-off state (the main refrigerant path is connected to the first refrigerant branch), and the solenoid valve 83 is opened to concentrate heat to defrost the first sub-heat exchanger 210 first. When the frost on the first sub-heat exchanger 210 is completely removed, the pipeline switching component 500 is in a power-on state (the main refrigerant path is connected to the second refrigerant branch), and the solenoid valve 83 is closed to concentrate heat to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the pipeline switching component 500 is in a power-off state, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0126] In some embodiments, the first throttling assembly includes a second electronic expansion valve and a second capillary tube;

[0127] The second electronic expansion valve is arranged in the main refrigerant circuit;

[0128] Alternatively, a portion of the refrigerant branch is provided with a second electronic expansion valve, and another portion of the refrigerant branch is provided with a second capillary tube.

[0129] The above two situations refer to Fig. 9 and Fig.10 shown.

[0130] The first case refers to Fig. 9As shown, an air conditioner with two sub-heat exchangers is used as an example for explanation, the outdoor heat exchanger is divided into a first sub-heat exchanger 210 and a second sub-heat exchanger 220, the first sub-heat exchanger 210 and the second sub-heat exchanger 220 are connected in parallel, and are respectively provided with a first refrigerant branch and a second refrigerant branch, the management switching component is a three-way valve, one end of the three-way valve is connected to the refrigerant main circuit, and the remaining two ends are respectively connected to the first refrigerant branch and the second refrigerant branch, and a second electronic expansion valve is provided in the refrigerant main circuit. For the convenience of distinction, the second electronic expansion valve in the refrigerant main circuit is recorded as electronic expansion valve 91; at this time, under the defrosting condition, if the hot gas bypass method is used to defrost the first sub-heat exchanger 210 and the second sub-heat exchanger 220 in turn, the compressor 100 operates normally, and the four-way valve is connected to the first refrigerant branch and the second refrigerant branch. The valve 400 switches to the valve state of the heating cycle, the indoor fan stops, the pipeline switching component 500 is in a power-off state (the main refrigerant circuit is connected to the first refrigerant branch), and the electronic expansion valve 91 is controlled to be in a certain opening or automatically adjusted to a suitable opening in real time, so as to first concentrate heat to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the pipeline switching component 500 is in a power-on state (the main refrigerant circuit is connected to the second refrigerant branch), and concentrates heat to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the electronic expansion valve 91 is closed, the pipeline switching component 500 is in a power-off state, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0131] The second case refers to Fig.10As shown, an air conditioner with two sub-heat exchangers is used as an example for explanation. The outdoor heat exchanger is divided into a first sub-heat exchanger 210 and a second sub-heat exchanger 220. The first sub-heat exchanger 210 and the second sub-heat exchanger 220 are connected in parallel, and are respectively provided with a first refrigerant branch and a second refrigerant branch. The management switching component is a three-way valve, one end of the three-way valve is connected to the refrigerant main circuit, and the remaining two ends are respectively connected to the first refrigerant branch and the second refrigerant branch. A second capillary tube is provided in the first refrigerant branch, and a second electronic expansion valve is provided in the second refrigerant branch. For the convenience of distinction, the second capillary tube in the second refrigerant branch is recorded as capillary tube 101, and the second electronic expansion valve in the first refrigerant branch is recorded as electronic expansion valve 102. At this time, under the defrosting condition, if the hot gas bypass method is adopted, the first sub-heat exchanger 210 and the second sub-heat exchanger 220 are sequentially 0 for defrosting, the compressor 100 operates normally, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan stops, the pipeline switching component 500 is in a power-off state (the refrigerant main circuit is connected to the first refrigerant branch), the electronic expansion valve 102 is controlled to be in a certain opening or automatically adjusted to a suitable opening in real time, so as to first concentrate heat to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the pipeline switching component 500 is in a power-on state (the refrigerant main circuit is connected to the second refrigerant branch), closes the electronic expansion valve 102, and concentrates heat to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the pipeline switching component 500 is in a power-off state, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0132] In some embodiments, the air conditioner further includes a plurality of second throttling components, which correspond to the sub-heat exchangers one by one and are arranged in the pipeline between the corresponding sub-heat exchanger and the indoor heat exchanger 300. The second throttling components are electronic expansion valves or capillaries.

[0133] When the second throttling component is an electronic expansion valve, the setting position of the second throttling component can refer to Figures 1 to 10 The electronic expansion valve 610 and the electronic expansion valve 620 in the heat exchanger 210 are connected in series, that is, the electronic expansion valve 610 is connected in series with the first sub-heat exchanger 210, and the electronic expansion valve 620 is connected in series with the second sub-heat exchanger 220. In this case, when the first sub-heat exchanger 210 is defrosted, the electronic expansion valve 610 is additionally controlled to be fully opened and the electronic expansion valve 620 is closed. When the defrosting of the first sub-heat exchanger 210 is completed and the defrosting of the second sub-heat exchanger 220 is switched, the electronic expansion valve 610 is additionally controlled to be closed and the electronic expansion valve 620 is fully opened.

[0134] For the above Figures 1 to 10 The second throttling component may also be a capillary, which is respectively denoted as capillary 710 and capillary 720, and the following is obtained: Figures 11 to 20The control process of each architecture sequentially defrosting the first sub-heat exchanger 210 and the second sub-heat exchanger 220 can be directly referred to Figures 1 to 10 The control process described above will not be repeated here.

[0135] The present application also provides a defrosting method for an air conditioner, which is applied to the above Figures 1 to 20 Any air conditioner, refer to Fig.21 As shown, the defrosting method includes but is not limited to the following steps:

[0136] Step S100, under the defrost condition, control the first throttling component to connect the exhaust port of the compressor 100 to the refrigerant branch corresponding to the sub-heat exchanger to defrost the sub-heat exchanger in turn.

[0137] Under the defrost condition, by controlling the first throttling component in the bypass line, different sub-heat exchangers can be selected to connect to the exhaust port of the compressor 100, so that each sub-heat exchanger can be defrosted in turn. That is to say, one or a part of the sub-heat exchangers are defrosted each time, and then switched to another or another part of the sub-heat exchangers for defrosting after the defrosting is completed. Compared with the solution of defrosting the entire outdoor heat exchanger, the sub-heat exchanger area of ​​the present application is small, so the defrost area of ​​the air conditioner becomes smaller, which is beneficial for the compressor 100 to establish exhaust pressure, thereby improving the operating power of the compressor 100, and being able to supply more defrost heat, ultimately reducing the defrost time and achieving efficient and fast defrosting.

[0138] Among them, refer to Fig. 22 As shown, step S100 may specifically include the following steps:

[0139] Step S110, controlling the air conditioner to enter a heating cycle;

[0140] Step S120, determining a first target sub-heat exchanger that needs to be defrosted, controlling the first throttling component to connect the refrigerant branch from the exhaust port of the compressor 100 to the first target sub-heat exchanger, and shutting off the refrigerant branch from the exhaust port of the compressor 100 to other sub-heat exchangers;

[0141] Step S130: After the first target sub-heat exchanger completes defrosting, another sub-heat exchanger that needs to be defrosted is selected as the first target sub-heat exchanger for defrosting.

[0142] The bypass pipeline is composed of a refrigerant main line and a refrigerant branch line. The refrigerant main line is connected to the exhaust port of the compressor 100 and is used to receive the high-temperature and high-pressure refrigerant discharged by the compressor 100. The refrigerant branch line is equivalent to a bifurcated pipeline of the refrigerant main line. Each refrigerant branch line corresponds to a sub-heat exchanger and is connected to the pipeline between the corresponding sub-heat exchanger and the indoor heat exchanger 300. In this way, a refrigerant pipeline from the exhaust port of the compressor 100 to the refrigerant branch of each sub-heat exchanger is formed. By controlling the exhaust port of the compressor 100 to be connected to different refrigerant branches through the first throttling component, the sub-heat exchangers can be defrosted in sequence. Specifically, in the defrosting condition of the air conditioner, the controller controls the first throttling component to connect the bypass line, so that the exhaust port of the compressor 100 is connected to the refrigerant branch where the sub-heat exchanger is located through the bypass line, and one or part of the sub-heat exchangers can be selected through the first throttling component, so that the high-temperature and high-pressure refrigerant will flow into one or part of the selected sub-heat exchangers, so as to perform centralized defrosting on one or part of the selected sub-heat exchangers, and after completing the defrosting of this part, another or another part of the sub-heat exchangers will be selected for defrosting. Therefore, the entire defrosting process is manifested as defrosting one or part of the sub-heat exchangers each time, and when the defrosting of all the sub-heat exchangers that need to be defrosted is completed, the entire defrosting process is completed.

[0143] In the above-mentioned hot gas bypass defrosting process, the compressor 100 can adjust the operating frequency in a certain manner, for example, referring to Fig.23 As shown, after controlling the air conditioner to enter a heating cycle, the defrosting method further includes:

[0144] Step S111, when the exhaust temperature of the compressor 100 is lower than the preset exhaust temperature, gradually increase the operating frequency of the compressor 100;

[0145] Step S112: during the process of gradually increasing the operating frequency of the compressor 100, when at least one of the following conditions is met, stop increasing the operating frequency of the compressor 100:

[0146] The exhaust temperature of the compressor 100 reaches a preset exhaust temperature;

[0147] The operating frequency of the compressor 100 reaches a preset operating frequency threshold;

[0148] The exhaust pressure of the compressor 100 reaches a preset exhaust pressure threshold.

[0149] The operating frequency of the compressor 100 is adjusted according to its exhaust temperature, that is, when the exhaust temperature is lower than a certain value (preset exhaust temperature), the operating frequency of the compressor 100 is increased at a certain speed, and each frequency increase is performed at a certain time interval, that is, the operating frequency of the compressor 100 is increased according to the preset time interval and the preset frequency step; it can be understood that when the above conditions are met, the operating frequency of the compressor 100 is stopped from being increased, and the current operating frequency of the compressor 100 can be kept unchanged until the entire defrosting process of the sub-heat exchanger is completed.

[0150] Regarding the above Figures 1 to 20 In the case where an electronic expansion valve is connected in series with a sub-heat exchanger, in addition to controlling the frequency of the compressor 100 according to the above steps S111 and S112, the opening of the electronic expansion valve connected in series with the sub-heat exchanger can also be controlled. Specifically, the first throttling component includes a target electronic expansion valve, which is connected in series with the first target sub-heat exchanger; Fig.24 As shown, after controlling the air conditioner to enter a heating cycle, the defrosting method further includes:

[0151] Step S113, when the exhaust temperature of the compressor 100 is lower than the preset exhaust temperature, gradually increase the operating frequency of the compressor 100 and gradually reduce the opening of the target electronic expansion valve;

[0152] Step S114, in the process of gradually increasing the operating frequency of the compressor 100 and gradually decreasing the opening of the target electronic expansion valve, when the exhaust temperature of the compressor 100 reaches the preset exhaust temperature, or the exhaust pressure of the compressor 100 reaches the preset exhaust pressure threshold, stop increasing the operating frequency of the compressor 100 and stop decreasing the opening of the target electronic expansion valve; when the opening of the target electronic expansion valve is closed to the preset opening threshold, stop decreasing the opening of the target electronic expansion valve; when the operating frequency of the compressor 100 reaches the preset operating frequency threshold, stop increasing the operating frequency of the compressor 100.

[0153] It can be seen that when the exhaust temperature of the compressor 100 is lower than a certain value (preset exhaust temperature), the operating frequency of the compressor 100 is increased at a certain speed, and the opening of the target electronic expansion valve is closed at a certain speed. At this time, the operating frequency of the compressor 100 and the opening of the target electronic expansion valve are adjusted at a certain time interval. Combining the above steps S112 and S114, it can be seen that the conditions for stopping the adjustment of the compressor 100 and the target electronic expansion valve include:

[0154] When the exhaust temperature of the compressor 100 reaches the preset exhaust temperature, the operating frequency of the compressor 100 and the opening degree of the target electronic expansion valve no longer change;

[0155] When the opening degree of the target electronic expansion valve is closed to the preset opening degree threshold, the opening degree of the target electronic expansion valve no longer changes;

[0156] When the operating frequency of the compressor 100 reaches the preset operating frequency threshold, the operating frequency of the compressor 100 no longer changes;

[0157] When the exhaust pressure of the compressor 100 reaches the preset exhaust pressure threshold, the operating frequency of the compressor 100 and the opening degree of the target electronic expansion valve no longer change.

[0158] Before executing the hot gas bypass defrosting, it can also be determined whether to first execute reverse cycle defrosting for a period of time according to the indoor ambient temperature. Fig.25 As shown, the above-mentioned defrosting method also includes:

[0159] Step S210, in the defrosting condition, when the indoor ambient temperature is higher than the preset temperature value, the throttling component is controlled to shut off the refrigerant branch corresponding to the exhaust port of the compressor 100 to the sub-heat exchanger, and the sub-heat exchanger is defrosted in sequence according to the refrigeration cycle of the air conditioner;

[0160] Step S220, under the defrost condition, when the indoor ambient temperature is lower than the preset temperature value, the first throttling component is controlled to connect the exhaust port of the compressor 100 to the refrigerant branch corresponding to the sub-heat exchanger to defrost the sub-heat exchanger in turn.

[0161] The air conditioner further includes a plurality of second throttling components, each of which corresponds to a sub-heat exchanger and is arranged in a pipeline between the corresponding sub-heat exchanger and the indoor heat exchanger 300; Fig.26 As shown, in the above step S220, the sub-heat exchanger is defrosted according to the refrigeration cycle of the air conditioner, including:

[0162] Step S221, determining a second target sub-heat exchanger that needs to be defrosted, turning on the second throttling component corresponding to the second target sub-heat exchanger, and turning off the second throttling components corresponding to other sub-heat exchangers;

[0163] Step S222: After the second target sub-heat exchanger completes defrosting, another sub-heat exchanger that needs to be defrosted is selected as the second target sub-heat exchanger for defrosting.

[0164] Reverse cycle defrosting also defrosts the sub-heat exchangers in sequence. An air conditioner with two sub-heat exchangers is used as an example for explanation. The outdoor heat exchanger is divided into a first sub-heat exchanger 210 and a second sub-heat exchanger 220. The first sub-heat exchanger 210 and the second sub-heat exchanger 220 are connected in parallel, and are respectively provided with a first refrigerant branch and a second refrigerant branch. The reverse cycle defrosting does not open the bypass pipeline, so the four-way valve 400 switches to the valve state of the refrigeration cycle, the indoor fan stops, and the target electronic expansion of the first sub-heat exchanger 210 is The expansion valve is fully opened, the target electronic expansion valve of the second sub-heat exchanger 220 is closed, and the heat is concentrated to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the target electronic expansion valve of the first sub-heat exchanger 210 is closed, and the target electronic expansion valve of the second sub-heat exchanger 220 is fully opened, and the heat is concentrated to defrost the second sub-heat exchanger 220. During the above defrosting process, when it is detected that the indoor ambient temperature is lower than the preset temperature value, it is immediately switched to the hot gas bypass mode for defrosting. When the frost on the first sub-heat exchanger 210 and the second sub-heat exchanger 220 is completely removed, the four-way valve 400 is switched to the valve state of the heating cycle, and then the indoor fan is turned on, and the air conditioner operates in the normal heating mode.

[0165] The air conditioner and the defrosting method thereof of the present application are described in detail below through several specific examples.

[0166] The following examples satisfy the following requirements: the outdoor heat exchanger of the air conditioner is divided into a first sub-heat exchanger 210 and a second sub-heat exchanger 220. When the system enters the defrost condition, the defrost method is determined according to the indoor ambient temperature. If the indoor ambient temperature is higher than a certain value, reverse cycle defrost is used first, and then hot air bypass defrost is used. If the indoor ambient temperature is lower than a certain value, hot air bypass defrost is used directly.

[0167] Example 1

[0168] Reference Figure 1 The architecture shown.

[0169] The reverse cycle defrost control process is as follows: the four-way valve 400 switches to the valve state of the refrigeration cycle, the indoor fan stops, the indoor expansion valve of the indoor heat exchanger 300 opens to the maximum, the electronic expansion valve 610 opens to the maximum, the electronic expansion valve 620 is closed, the solenoid valve 11 and the solenoid valve 13 are closed, and the heat is first concentrated to quickly defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the electronic expansion valve 610 is closed, the electronic expansion valve 620 opens to the maximum, the solenoid valve 11 and the solenoid valve 13 are closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0170] The hot gas bypass defrost control process is as follows: the four-way valve 400 is switched to the valve state of the heating cycle, the indoor fan is stopped, the indoor expansion valve of the indoor heat exchanger 300 is opened to the maximum, the electronic expansion valve 610 and the electronic expansion valve 620 are at a certain opening or automatically adjusted to a suitable opening in real time, the solenoid valve 11 is opened, the solenoid valve 13 is closed, and the heat is first concentrated to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the solenoid valve 13 is opened, the solenoid valve 11 is closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the solenoid valve 13 is closed, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0171] The operating frequency control process of the compressor 100 under the hot gas bypass defrosting condition is as follows: the operating frequency of the compressor 100 is jointly determined by its own exhaust temperature, exhaust pressure and the opening of the electronic expansion valve (if it is a capillary tube, this component does not participate in the operating frequency control of the compressor 100). Please refer to the description of the above steps S113 and S114. This can ensure that the exhaust temperature of the compressor 100 is above a certain value to ensure the defrosting effect.

[0172] Example 2

[0173] Reference Figure 2 The architecture shown.

[0174] The reverse cycle defrost control process is as follows: the four-way valve 400 switches to the valve state of the refrigeration cycle, the indoor fan stops, the indoor expansion valve of the indoor heat exchanger 300 opens to the maximum, the electronic expansion valve 610 opens to the maximum, the electronic expansion valve 620 is closed, the solenoid valve 21 and the solenoid valve 22 are closed, and the heat is first concentrated to quickly defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the electronic expansion valve 610 is closed, the electronic expansion valve 620 opens to the maximum, the solenoid valve 21 and the solenoid valve 22 are closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0175] The hot gas bypass defrost control process is as follows: the four-way valve 400 is switched to the valve state of the heating cycle, the indoor fan is stopped, the indoor expansion valve of the indoor heat exchanger 300 is opened to the maximum, the electronic expansion valve 610 and the electronic expansion valve 620 are at a certain opening or automatically adjusted to a suitable opening in real time, the solenoid valve 21 is opened, the solenoid valve 22 is closed, and the heat is first concentrated to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the solenoid valve 22 is opened, the solenoid valve 21 is closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the solenoid valve 22 is closed, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0176] The operating frequency control process of the compressor 100 under hot gas bypass defrosting conditions may refer to Example 1.

[0177] Example 3

[0178] Reference Figure 3 The architecture shown.

[0179] The reverse cycle defrost control process is as follows: the four-way valve 400 switches to the valve state of the refrigeration cycle, the indoor fan stops, the indoor expansion valve of the indoor heat exchanger 300 opens to the maximum, the electronic expansion valve 610 opens to the maximum, the electronic expansion valve 620 is closed, the electronic expansion valve 31 and the electronic expansion valve 32 are closed, and the heat is first concentrated to quickly defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the electronic expansion valve 610 is closed, the electronic expansion valve 620 opens to the maximum, the electronic expansion valve 31 and the electronic expansion valve 32 are closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0180] The hot gas bypass defrost control process is as follows: the four-way valve 400 is switched to the valve state of the heating cycle, the indoor fan is stopped, the indoor expansion valve of the indoor heat exchanger 300 is opened to the maximum, the electronic expansion valve 610 and the electronic expansion valve 620 are at a certain opening or automatically adjusted to a suitable opening in real time, the electronic expansion valve 31 is controlled to be at a certain opening or automatically adjusted to a suitable opening in real time, the electronic expansion valve 32 is closed, and the heat is first concentrated to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the electronic expansion valve 31 is closed, the electronic expansion valve 32 is controlled to be at a certain opening or automatically adjusted to a suitable opening in real time, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the electronic expansion valve 32 is closed, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0181] The operating frequency control process of the compressor 100 under hot gas bypass defrosting conditions may refer to Example 1.

[0182] Example 4

[0183] Reference Figure 4 The architecture shown.

[0184] The reverse cycle defrost control process is as follows: the four-way valve 400 switches to the valve state of the refrigeration cycle, the indoor fan stops, the indoor expansion valve of the indoor heat exchanger 300 opens to the maximum, the electronic expansion valve 610 opens to the maximum, the electronic expansion valve 620 is closed, the solenoid valve 41 and the electronic expansion valve 43 are closed, and the heat is first concentrated to quickly defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the electronic expansion valve 610 is closed, the electronic expansion valve 620 opens to the maximum, the solenoid valve 41 and the electronic expansion valve 43 are closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0185] The hot gas bypass defrost control process is as follows: the four-way valve 400 is switched to the valve state of the heating cycle, the indoor fan is stopped, the indoor expansion valve of the indoor heat exchanger 300 is opened to the maximum, the electronic expansion valve 610 and the electronic expansion valve 620 are at a certain opening or automatically adjusted to a suitable opening in real time, the solenoid valve 41 is opened, the electronic expansion valve 43 is closed, and the heat is first concentrated to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the solenoid valve 41 is closed, and the electronic expansion valve 43 is controlled to be at a certain opening or automatically adjusted to a suitable opening in real time, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the electronic expansion valve 43 is closed, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0186] The operating frequency control process of the compressor 100 under hot gas bypass defrosting conditions may refer to Example 1.

[0187] Example 5

[0188] Reference Figure 5 The architecture shown.

[0189] The reverse cycle defrost control process is as follows: the four-way valve 400 switches to the valve state of the refrigeration cycle, the indoor fan stops, the indoor expansion valve of the indoor heat exchanger 300 opens to the maximum, the electronic expansion valve 610 opens to the maximum, the electronic expansion valve 620 is closed, the solenoid valve 51 is closed, and the heat is first concentrated to quickly defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the electronic expansion valve 610 is closed, the electronic expansion valve 620 opens to the maximum, the solenoid valve 51 is closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0190] The hot gas bypass defrost control process is as follows: the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan stops, the indoor expansion valve of the indoor heat exchanger 300 is opened to the maximum, the electronic expansion valve 610 and the electronic expansion valve 620 are at a certain opening or automatically adjusted to a suitable opening in real time, the solenoid valve 51 is opened, and the pipeline switching component 500 is in a power-off state (the main refrigerant path is connected to the first refrigerant branch), so as to first concentrate heat to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the pipeline switching component 500 is in a power-on state (the main refrigerant path is connected to the second refrigerant branch), and concentrates heat to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the solenoid valve 51 is closed, the pipeline switching component 500 is in a power-off state, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0191] The operating frequency control process of the compressor 100 under hot gas bypass defrosting conditions may refer to Example 1.

[0192] Example 6

[0193] Reference Figure 6 The architecture shown.

[0194] The reverse cycle defrost control process is as follows: the four-way valve 400 switches to the valve state of the refrigeration cycle, the indoor fan stops, the indoor expansion valve of the indoor heat exchanger 300 opens to the maximum, the electronic expansion valve 610 opens to the maximum, the electronic expansion valve 620 is closed, the solenoid valve 62 and the solenoid valve 63 are closed, and the heat is first concentrated to quickly defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the electronic expansion valve 610 is closed, the electronic expansion valve 620 opens to the maximum, the solenoid valve 62 and the solenoid valve 63 are closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0195] The hot gas bypass defrost control process is as follows: the four-way valve 400 is switched to the valve state of the heating cycle, the indoor fan is stopped, the indoor expansion valve of the indoor heat exchanger 300 is opened to the maximum, the electronic expansion valve 610 and the electronic expansion valve 620 are at a certain opening or automatically adjusted to a suitable opening in real time, the solenoid valve 62 is opened, the solenoid valve 63 is closed, and the pipeline switching component 500 is in a power-off state (the main refrigerant path is connected to the first refrigerant branch), so that heat is first concentrated to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the solenoid valve 62 is closed, the solenoid valve 63 is opened, and the pipeline switching component 500 is in a power-on state (the main refrigerant path is connected to the second refrigerant branch), and heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the solenoid valve 63 is closed, the pipeline switching component 500 is in a power-off state, and then the indoor fan is turned on, and the air conditioner operates in a normal heating mode.

[0196] The operating frequency control process of the compressor 100 under hot gas bypass defrosting conditions may refer to Example 1.

[0197] Example 7

[0198] Reference Figure 7 The architecture shown.

[0199] The reverse cycle defrost control process is as follows: the four-way valve 400 switches to the valve state of the refrigeration cycle, the indoor fan stops, the indoor expansion valve of the indoor heat exchanger 300 opens to the maximum, the electronic expansion valve 610 opens to the maximum, the electronic expansion valve 620 is closed, the solenoid valve 71 is closed, and the heat is first concentrated to quickly defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the electronic expansion valve 610 is closed, the electronic expansion valve 620 opens to the maximum, the solenoid valve 71 is closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0200] The hot gas bypass defrost control process is as follows: the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan stops, the indoor expansion valve of the indoor heat exchanger 300 is opened to the maximum, the electronic expansion valve 610 and the electronic expansion valve 620 are at a certain opening or automatically adjusted to a suitable opening in real time, the solenoid valve 71 is opened, and the pipeline switching component 500 is in a power-off state (the main refrigerant path is connected to the first refrigerant branch), so as to first concentrate heat to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the pipeline switching component 500 is in a power-on state (the main refrigerant path is connected to the second refrigerant branch), and concentrates heat to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the solenoid valve 71 is closed, the pipeline switching component 500 is in a power-off state, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0201] The operating frequency control process of the compressor 100 under hot gas bypass defrosting conditions may refer to Example 1.

[0202] Example 8

[0203] Reference Figure 8 The architecture shown.

[0204] The reverse cycle defrost control process is as follows: the four-way valve 400 switches to the valve state of the refrigeration cycle, the indoor fan stops, the indoor expansion valve of the indoor heat exchanger 300 opens to the maximum, the electronic expansion valve 610 opens to the maximum, the electronic expansion valve 620 is closed, the solenoid valve 83 is closed, and the heat is first concentrated to quickly defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the electronic expansion valve 610 is closed, the electronic expansion valve 620 opens to the maximum, the solenoid valve 83 is closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0205] The hot gas bypass defrost control process is as follows: the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan stops, the indoor expansion valve of the indoor heat exchanger 300 is opened to the maximum, the electronic expansion valve 610 and the electronic expansion valve 620 are at a certain opening or automatically adjusted to a suitable opening in real time, the solenoid valve 83 is opened, and the pipeline switching component 500 is in a power-off state (the main refrigerant path is connected to the first refrigerant branch), so as to first concentrate heat to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the solenoid valve 83 is closed, and the pipeline switching component 500 is in a power-on state (the main refrigerant path is connected to the second refrigerant branch), and heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the pipeline switching component 500 is in a power-off state, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0206] The operating frequency control process of the compressor 100 under hot gas bypass defrosting conditions may refer to Example 1.

[0207] Example 9

[0208] Reference Fig. 9 The architecture shown.

[0209] The reverse cycle defrost control process is as follows: the four-way valve 400 switches to the valve state of the refrigeration cycle, the indoor fan stops, the indoor expansion valve of the indoor heat exchanger 300 opens to the maximum, the electronic expansion valve 610 opens to the maximum, the electronic expansion valve 620 is closed, the electronic expansion valve 91 is closed, and the heat is first concentrated to quickly defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the electronic expansion valve 610 is closed, the electronic expansion valve 620 opens to the maximum, the electronic expansion valve 91 is closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0210] The hot gas bypass defrost control process is as follows: the four-way valve 400 is switched to the valve state of the heating cycle, the indoor fan is stopped, the indoor expansion valve of the indoor heat exchanger 300 is opened to the maximum, the electronic expansion valve 610 and the electronic expansion valve 620 are at a certain opening or automatically adjusted to a suitable opening in real time, the electronic expansion valve 91 is controlled to be at a certain opening or automatically adjusted to a suitable opening in real time, and the pipeline switching component 500 is in a power-off state (the refrigerant main circuit is connected to the first refrigerant branch), so as to first concentrate heat to defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the pipeline switching component 500 is in a power-on state (the refrigerant main circuit is connected to the second refrigerant branch), and concentrates heat to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the electronic expansion valve 91 is closed, the pipeline switching component 500 is in a power-off state, and then the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0211] The operating frequency control process of the compressor 100 under hot gas bypass defrosting conditions may refer to Example 1.

[0212] Example 10

[0213] Reference Fig.10 The architecture shown.

[0214] The reverse cycle defrost control process is as follows: the four-way valve 400 switches to the valve state of the refrigeration cycle, the indoor fan stops, the indoor expansion valve of the indoor heat exchanger 300 opens to the maximum, the electronic expansion valve 610 opens to the maximum, the electronic expansion valve 620 is closed, the electronic expansion valve 102 is closed, and the heat is first concentrated to quickly defrost the first sub-heat exchanger 210. When the frost on the first sub-heat exchanger 210 is completely removed, the electronic expansion valve 610 is closed, the electronic expansion valve 620 opens to the maximum, the electronic expansion valve 102 is closed, and the heat is concentrated to defrost the second sub-heat exchanger 220. When the frost on the second sub-heat exchanger 220 is completely removed, the four-way valve 400 switches to the valve state of the heating cycle, the indoor fan is turned on, and the air conditioner operates in normal heating mode.

[0215] The hot gas bypass defrost control process is as follows: the four-way valve 400 is switched to the valve state of the heating cycle, the indoor fan is stopped, the indoor expansion valve of the indoor heat exchanger 300 is opened to the maximum, the electronic expansion valve 610 and the electronic expansion valve 620 are at a certain opening or automatically adjusted to a suitable opening in real time, the electronic expansion valve 102 is controlled to be at a certain opening or automatically adjusted to a suitable opening in real time, the pipeline switching component 500 is in a power-off state (the refrigerant main circuit is connected to the first refrigerant branch), so as to first concentrate heat to defrost the first sub-heat exchanger 210, and when the frost on the first sub-heat exchanger 210 is completely removed, the electronic expansion valve 102 is closed, the pipeline switching component 500 is in a power-on state (the refrigerant main circuit is connected to the second refrigerant branch), and the heat is concentrated to defrost the second sub-heat exchanger 220, and when the frost on the second sub-heat exchanger 220 is completely removed, the pipeline switching component 500 is in a power-off state, and then the indoor fan is turned on, and the air conditioner operates in a normal heating mode.

[0216] The operating frequency control process of the compressor 100 under hot gas bypass defrosting conditions may refer to Example 1.

[0217] It is worth noting that the electronic expansion valve 610 and the electronic expansion valve 620 in Examples 1 to 10 can be replaced by the capillary tube 710 and the capillary tube 720. Accordingly, the reverse cycle defrosting control process is as follows: the four-way valve 400 is switched to the valve state of the refrigeration cycle, the indoor fan is stopped, the indoor expansion valve of the indoor heat exchanger 300 is opened to the maximum, and the first sub-heat exchanger 210 and the second sub-heat exchanger 220 are defrosted. When the frost on the first sub-heat exchanger 210 and the second sub-heat exchanger 220 is completely removed, the four-way valve 400 is switched to the valve state of the heating cycle, the indoor fan is turned on, and the air conditioner operates in the normal heating mode. The hot gas bypass defrosting control process is the same and will not be repeated here.

[0218] An embodiment of the present application also provides a controller, comprising at least one processor and a memory for communicating with the at least one processor; the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the defrost method of the air conditioner as described in the above embodiment.

[0219] It will be appreciated by those skilled in the art that all or some of the steps and systems in the disclosed method above may be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or may be implemented as hardware, or may be implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or a non-transitory medium) and a communication medium (or a temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0220] The above is a specific description of the preferred implementation of the present application, but the present application is not limited to the above-mentioned implementation mode. Technical personnel familiar with the field can also make various equivalent deformations or substitutions without violating the spirit of the present application. These equivalent deformations or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. An air conditioner comprising a compressor, an outdoor heat exchanger and an indoor heat exchanger, characterized in that: The outdoor heat exchanger includes a plurality of sub-heat exchangers connected in parallel, and the air conditioner further includes: A bypass pipeline, wherein the bypass pipeline is provided with a first throttling assembly, the bypass pipeline comprises a refrigerant main pipeline and a plurality of refrigerant branches connected to the refrigerant main pipeline, the refrigerant main pipeline is connected to the exhaust port of the compressor, the refrigerant branches correspond to the sub-heat exchangers one by one, and are connected to the pipeline between the corresponding sub-heat exchanger and the indoor heat exchanger; The controller is used to control the throttling component to connect the exhaust port of the compressor to the refrigerant branch corresponding to the sub-heat exchanger under the defrosting condition, so as to defrost the sub-heat exchanger in turn.

2. The air conditioner according to claim 1, characterized in that: The first throttling assembly includes a first solenoid valve and a first capillary tube, and the first solenoid valve and the first capillary tube are connected in series; Each of the refrigerant branches is provided with the first solenoid valve and the first capillary tube; Alternatively, the refrigerant main circuit is provided with the first capillary tube, and each of the refrigerant branch circuits is provided with the first solenoid valve.

3. The air conditioner according to claim 1, characterized in that: The first throttling component includes a plurality of first electronic expansion valves, and each of the refrigerant branches is provided with the first electronic expansion valve.

4. The air conditioner according to claim 1, characterized in that: The first throttling assembly includes a first electronic expansion valve, a first solenoid valve and a first capillary tube, wherein the first solenoid valve and the first capillary tube are connected in series; A portion of the refrigerant branch is provided with the first electronic expansion valve, and another portion of the refrigerant branch is provided with the first solenoid valve and the first capillary tube.

5. The air conditioner according to claim 1, characterized in that: A pipeline switching component is arranged between the refrigerant main circuit and the refrigerant main circuit. The controller is also used to control the first throttling component and the pipeline switching component under the defrosting condition, connecting the exhaust port of the compressor to the refrigerant branch corresponding to the sub-heat exchanger to defrost the sub-heat exchanger in turn.

6. The air conditioner according to claim 5, characterized in that: The first throttling assembly comprises a second solenoid valve and a second capillary tube, wherein the first solenoid valve and the first capillary tube are connected in series; The refrigerant main circuit is provided with the second solenoid valve, and each of the refrigerant branch circuits is provided with the second capillary tube; Alternatively, the refrigerant main circuit is provided with the second capillary tube, and each of the refrigerant branch circuits is provided with the second solenoid valve; Alternatively, the refrigerant main circuit is provided with the second solenoid valve and the second capillary tube; Alternatively, a portion of the refrigerant branch is provided with the second solenoid valve and the second capillary tube, and another portion of the refrigerant branch is provided with the second capillary tube.

7. The air conditioner according to claim 5, characterized in that: The first throttling assembly includes a second electronic expansion valve and a second capillary tube; The second electronic expansion valve is arranged on the refrigerant main circuit; Alternatively, a portion of the refrigerant branch is provided with the second electronic expansion valve, and another portion of the refrigerant branch is provided with the second capillary tube.

8. The air conditioner according to any one of claims 1 to 7, characterized in that: The air conditioner further comprises a plurality of second throttling components, which correspond one to one with the sub-heat exchangers and are arranged in the pipeline between the corresponding sub-heat exchangers and the indoor heat exchanger.

9. The air conditioner according to claim 8, characterized in that: The second throttling component is an electronic expansion valve or a capillary tube.

10. A defrosting method for an air conditioner, characterized in that: Applied to the air conditioner according to any one of claims 1 to 9, the defrosting method comprises: Under the defrosting condition, the throttling component is controlled to connect the exhaust port of the compressor to the refrigerant branch corresponding to the sub-heat exchanger, so as to defrost the sub-heat exchanger in turn.

11. The defrosting method according to claim 10, characterized in that: The controlling the throttling assembly to connect the exhaust port of the compressor to the refrigerant branch corresponding to the sub-heat exchanger to defrost the sub-heat exchanger in sequence includes: Controlling the air conditioner to enter a heating cycle; Determine a first target sub-heat exchanger that needs to be defrosted, control the throttling component to connect the refrigerant branch from the exhaust port of the compressor to the first target sub-heat exchanger, and shut off the refrigerant branch from the exhaust port of the compressor to other sub-heat exchangers; After the first target sub-heat exchanger completes defrosting, another sub-heat exchanger that needs to be defrosted is selected as the first target sub-heat exchanger for defrosting.

12. The defrosting method according to claim 11, characterized in that: After controlling the air conditioner to enter a heating cycle, the defrosting method further includes: When the exhaust temperature of the compressor is lower than a preset exhaust temperature, gradually increasing the operating frequency of the compressor; In the process of gradually increasing the operating frequency of the compressor, when at least one of the following conditions is met, the increasing of the operating frequency of the compressor is stopped: The exhaust temperature of the compressor reaches the preset exhaust temperature; The operating frequency of the compressor reaches a preset operating frequency threshold; The exhaust pressure of the compressor reaches a preset exhaust pressure threshold.

13. The defrosting method according to claim 12, characterized in that: The step of gradually increasing the operating frequency of the compressor comprises: The operating frequency of the compressor is increased according to a preset time interval and a preset frequency step.

14. The defrosting method according to claim 12, characterized in that: The first throttling assembly includes a target electronic expansion valve, and the target electronic expansion valve is connected in series with the first target sub-heat exchanger; After controlling the air conditioner to enter a heating cycle, the defrosting method further includes: When the exhaust temperature of the compressor is lower than the preset exhaust temperature, gradually increasing the operating frequency of the compressor and gradually reducing the opening of the target electronic expansion valve; In the process of gradually increasing the operating frequency of the compressor and gradually decreasing the opening of the target electronic expansion valve, when the exhaust temperature of the compressor reaches the preset exhaust temperature, or the exhaust pressure of the compressor reaches the preset exhaust pressure threshold, stop increasing the operating frequency of the compressor and stop decreasing the opening of the target electronic expansion valve; when the opening of the target electronic expansion valve is closed to the preset opening threshold, stop decreasing the opening of the target electronic expansion valve; when the operating frequency of the compressor reaches the preset operating frequency threshold, stop increasing the operating frequency of the compressor.

15. The defrosting method according to claim 10, characterized in that: The defrosting method further comprises: In the defrosting condition, when the indoor ambient temperature is higher than the preset temperature value, the throttling component is controlled to shut off the refrigerant branch corresponding to the exhaust port of the compressor to the sub-heat exchanger, and the sub-heat exchanger is defrosted in sequence according to the refrigeration cycle of the air conditioner; In the defrosting condition, when the indoor ambient temperature is lower than the preset temperature value, the throttling component is controlled to connect the exhaust port of the compressor to the refrigerant branch corresponding to the sub-heat exchanger to defrost the sub-heat exchanger in turn.

16. The defrosting method according to claim 15, characterized in that: The air conditioner further comprises a plurality of second throttling components, each of which corresponds to each of the sub-heat exchangers and is arranged in a pipeline between the corresponding sub-heat exchanger and the indoor heat exchanger; The defrosting of the sub-heat exchanger according to the refrigeration cycle of the air conditioner comprises: Determine a second target sub-heat exchanger that needs to be defrosted, turn on the second throttling component corresponding to the second target sub-heat exchanger, and turn off the second throttling components corresponding to the other sub-heat exchangers; After the second target sub-heat exchanger completes defrosting, another sub-heat exchanger that needs to be defrosted is selected as the second target sub-heat exchanger for defrosting.

17. A controller, characterized in that It includes at least one processor and a memory for communicating with the at least one processor; the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the defrosting method of the air conditioner as described in any one of claims 10 to 16.

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