Defrosting system and air conditioner

Abstract

The invention relates to the technical field of air conditioners, and discloses a defrosting system which comprises a frosting detection device electrically connected with a controller and used for detecting and sending the frosting condition of a heat exchanger to the controller; the controller is electrically connected with the external defrosting device, and the controller is used for triggering the external defrosting device to heat the heat exchanger when the frosting condition is that the heat exchanger is frosted; and the external defrosting device is arranged on the heat exchanger and used for heating the heat exchanger. In this way, the surface of the heat exchanger can be heated, so that frost on the heat exchanger is melted, no refrigerant flows in the reversing mode in the defrosting process, balance does not need to be established again, and the probability of indoor temperature fluctuation can be reduced. The invention further discloses the air conditioner.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioning, for example, to a system for defrosting and an air conditioner. Background Art

[0002] At present, when the air conditioner is running in winter for heating, the air conditioner outdoor unit absorbs heat from the outdoor air, and the temperature around the outdoor heat exchanger is low, so the water vapor in the air will condense into frost and adhere to the surface of the outdoor heat exchanger. Thick frost will reduce the heat exchange capacity of the air conditioner outdoor unit, thereby reducing the heating efficiency of the air conditioner. The existing technology is to switch the air conditioner operation state to the refrigeration cycle mode, so that the high-temperature and high-pressure refrigerant discharged by the compressor is discharged into the air conditioner outdoor unit through the four-way reversing valve to melt the frost layer on the air conditioner outdoor unit.

[0003] In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related art:

[0004] Since the air conditioner switches from a heating cycle to a cooling cycle during the defrosting process, the indoor temperature fluctuates greatly, resulting in a poor air conditioning experience.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0007] The embodiments of the present disclosure provide a defrosting system and an air conditioner, so as to reduce the probability of indoor temperature fluctuation during the defrosting process of the air conditioner.

[0008] In some embodiments, the defrosting system includes: a frost detection device electrically connected to the controller, the frost detection device is used to detect and send the frost condition of the heat exchanger to the controller. The controller is electrically connected to the external defrost device, the controller is used to trigger the external defrost device to heat the heat exchanger when the frost condition is that the heat exchanger is frosted; the external defrost device is arranged on the heat exchanger and is used to heat the heat exchanger.

[0009] In some embodiments, the system for defrosting, the frost thickness detection device is electrically connected to the controller, and the frost thickness detection device is used to detect and send the frost thickness on the heat exchanger to the controller.

[0010] In some embodiments, the controller is further configured to trigger a frost layer thickness detection device to detect the thickness of the frost layer on the heat exchanger when the frosting condition is frosting of the heat exchanger.

[0011] In some embodiments, the controller is further used to determine a heating temperature according to the thickness of the frost layer, and trigger an external defrost device to heat the heat exchanger according to the heating temperature.

[0012] In some embodiments, the controller determines the heating temperature according to the frost layer thickness in the following manner: determining a temperature correction value according to a first difference between the frost layer thickness and a preset first thickness threshold; and using the temperature correction value to correct a preset initial temperature to obtain a heating temperature.

[0013] In some embodiments, the controller is used to determine a temperature correction value based on a first difference between the frost layer thickness and a preset first thickness threshold in the following manner: when the first difference between the frost layer thickness and the preset first thickness threshold is less than or equal to 0, the temperature correction value is determined to be 0; and / or, when the first difference between the frost layer thickness and the preset first thickness threshold is greater than 0, the temperature correction value is determined to be the product of the first difference and the preset correction value.

[0014] In some embodiments, the defrosting system further includes: an external fan electrically connected to the controller, and the external fan is arranged at the rear of the air conditioner outdoor unit.

[0015] In some embodiments, the controller is further used to determine a target rotation speed according to the thickness of the frost layer, and trigger the external fan to rotate at the target rotation speed.

[0016] In some embodiments, the defrosting system further includes: a temperature detection device electrically connected to the controller, the temperature detection device is used to detect and send the outdoor ambient temperature to the controller; a humidity detection device electrically connected to the controller, the humidity detection device is used to detect and send the outdoor ambient humidity to the controller.

[0017] In some embodiments, the controller is further configured to trigger a frost detection device to detect frost on the heat exchanger when the outdoor ambient temperature is lower than a set temperature and the outdoor ambient humidity is lower than a set humidity.

[0018] The defrosting system and air conditioner provided in the embodiments of the present disclosure can achieve the following technical effects: by utilizing a frost detection device to detect the frost condition of the heat exchanger, and utilizing a controller to control an external defrost device disposed on the heat exchanger to heat the heat exchanger when the heat exchanger is frosted, direct heating of the frost layer on the outer surface of the heat exchanger can be achieved. Since there is no reversing flow of the refrigerant during the defrosting process, there is no need to re-establish balance, thereby reducing the probability of indoor temperature fluctuations.

[0019] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

[0021] Figure 1 is a schematic diagram of a defrosting system provided by an embodiment of the present disclosure;

[0022] Figure 2 is a schematic diagram of another system for defrosting provided by an embodiment of the present disclosure;

[0023] Figure 3 is a schematic diagram of another system for defrosting provided by an embodiment of the present disclosure;

[0024] Figure 4 is a schematic diagram of another system for defrosting provided by an embodiment of the present disclosure;

[0025] Figure 5 is a schematic diagram of an air conditioner provided by an embodiment of the present disclosure;

[0026] Figure 6 is a schematic diagram of another air conditioner provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0027] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0028] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0029] Unless otherwise stated, the term "plurality" means two or more.

[0030] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B indicates: A or B.

[0031] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0032] The term "correspondence" may refer to an association relationship or a binding relationship. The correspondence between A and B means that there is an association relationship or a binding relationship between A and B.

[0033] Combination Figure 1 As shown, the embodiment of the present disclosure provides a system 100 for defrosting, including a frost detection device 101, a controller 102 and an external defrost device 103. The frost detection device 101 is electrically connected to the controller 102, and the frost detection device 101 is used to detect and send the frost condition of the heat exchanger to the controller 102. The frost condition is used to characterize whether the heat exchanger is frosted or not. The controller 102 is electrically connected to the external defrost device 103, and the controller 102 is used to trigger the external defrost device 103 to heat the heat exchanger when the frost condition is that the heat exchanger is frosted. The external defrost device 103 is used to heat the heat exchanger.

[0034] The defrosting system provided in the embodiment of the present disclosure detects the frosting condition of the heat exchanger by using a frost detection device, and controls the external defrost device provided on the heat exchanger to heat the heat exchanger when the heat exchanger is frosted by using a controller, thereby directly heating the frost layer on the outer surface of the heat exchanger. Since there is no reversing flow of the refrigerant during the defrosting process, there is no need to re-establish the balance, thereby reducing the possibility of indoor temperature fluctuations.

[0035] Optionally, the external defrost device is an electric heating device.

[0036] Further, the frost detection device 101 is arranged on the heat exchanger of the air conditioner, and upon receiving the frost detection instruction sent by the controller, the frost detection device detects the frost condition of the heat exchanger at intervals of a preset time period. The heat exchanger is arranged in the outdoor unit of the air conditioner. The frost detection device is, for example, a frost detection sensor.

[0037] Combination Figure 2As shown, the defrosting system 100 also includes a frost layer thickness detection device 104. The frost layer thickness detection device 104 is disposed on the heat exchanger, and the frost layer thickness detection device 104 is electrically connected to the controller 102. The frost layer thickness detection device 104 is used to detect and send the thickness of the frost layer on the heat exchanger to the controller 102. In some embodiments, the frost layer thickness detection device is an ultrasonic thickness gauge. Wherein, the frost layer thickness detection device detects the frost thickness of the heat exchanger when receiving a thickness detection instruction sent by the controller. Furthermore, when the frosting condition is that the heat exchanger is frosted, the controller sends a thickness detection instruction to the frost layer thickness detection device, triggering the frost layer detection device to detect the thickness of the frost layer on the heat exchanger.

[0038] Furthermore, the controller is also used to determine the interval time according to the thickness of the frost layer, and trigger the frost detection device to monitor the frost condition of the heat exchanger in real time after the interval time is reached. When the heat exchanger is not frosted, the external defrost device is controlled to be turned off. Since the thicker the frost layer, the longer the corresponding defrosting time is usually, it is not necessary to detect the thickness of the frost layer when it is known that the thickness of the frost layer on the heat exchanger is large. Therefore, determining the interval time according to the thickness of the frost layer and monitoring the frost condition of the heat exchanger only after the interval time is reached can reduce unnecessary detection steps, thereby saving energy.

[0039] Optionally, determining the interval time according to the thickness of the frost layer includes: matching the interval time corresponding to the thickness of the frost layer in a preset database. The database stores the corresponding relationship between the thickness of the frost layer and the interval time.

[0040] In some embodiments, when the frosting thickness is less than or equal to 1 mm, the interval time corresponding to the frosting thickness is 10 minutes. When the frosting thickness is greater than 1 mm and less than or equal to 5 mm, the interval time corresponding to the frosting thickness is 20 minutes. When the frosting thickness is greater than 5 mm, the interval time corresponding to the frosting thickness is 30 minutes.

[0041] Optionally, combined Figure 3 As shown, the defrosting system 100 further includes a frost layer image acquisition device 105, which is electrically connected to the controller 102. The frost layer image acquisition device 105 is used to acquire image information of the heat exchanger. Further, the frost layer image acquisition device acquires image information of the heat exchanger when receiving a frost layer thickness acquisition instruction sent by the controller. Further, when the frosting condition is that the heat exchanger is frosted, the controller sends a frost layer thickness acquisition instruction to the frost layer image acquisition device to trigger the image information of the heat exchanger fed back by the frost layer image acquisition device. Further, the controller is also used to input the image information into a preset frost thickness recognition model to obtain the frost thickness of the heat exchanger.

[0042] Optionally, the controller is further used to determine a heating temperature according to the thickness of the frost layer, and trigger an external defrost device to heat the heat exchanger according to the heating temperature.

[0043] Furthermore, the controller determines the heating temperature according to the thickness of the frost layer in the following manner: determining a temperature correction value according to a first difference between the thickness of the frost layer and a preset first thickness threshold; and correcting a preset initial temperature using the temperature correction value to obtain the heating temperature.

[0044] Optionally, determining the temperature correction value according to the first difference between the frost layer thickness and a preset first thickness threshold comprises: when the first difference between the frost layer thickness and the preset first thickness threshold is less than or equal to 0, determining the temperature correction value to be 0. And / or, when the first difference between the frost layer thickness and the preset first thickness threshold is greater than 0, determining the temperature correction value to be the product of the first difference and the preset correction value.

[0045] In some embodiments, a first difference between the frost layer thickness and the preset first thickness threshold is obtained by subtracting a preset first thickness threshold from the frost layer thickness.

[0046] In some embodiments, the preset first thickness threshold is 2 mm. The preset initial temperature is 100 degrees Celsius, and the preset correction value is 100 degrees Celsius. When the first difference between the frost layer thickness and the preset first thickness threshold is less than or equal to 0, that is, when the frost layer thickness is less than or equal to 2 mm, the temperature correction value is determined to be 0, and the heating temperature is directly determined to be 100 degrees Celsius. When the first difference between the frost layer thickness and the preset first thickness threshold is greater than 0, that is, when the frost layer thickness is greater than 2 mm, the temperature correction value is determined as the product of the first difference and the preset correction value. That is, when the frost layer thickness increases by 1 mm, the temperature of the infrared heating tube is increased by 100 degrees Celsius.

[0047] Optionally, the preset initial temperature is corrected by using the temperature correction value to obtain the heating temperature; including: determining the sum of the temperature correction value and the initial temperature as the heating temperature.

[0048] Optionally, the defrosting system further includes an external fan electrically connected to the controller, and the external fan is arranged at the rear of the air conditioner outer unit. Further, the external fan rotates according to the target speed when receiving the target speed sent by the controller. In this way, the air circulation speed can be accelerated, thereby accelerating the defrosting efficiency. Among them, the controller determines the target speed according to the thickness of the frost layer. The external fan is coaxially connected to the internal fan of the air conditioner.

[0049] Optionally, the controller is further used to determine a target rotation speed according to the thickness of the frost layer, and trigger the external fan to rotate at the target rotation speed.

[0050] Further, the target speed of the external fan is determined according to the thickness of the frost layer, including: when the thickness of the frost layer is less than a preset second thickness threshold, determining the target speed of the external fan to be 0. And / or, when the thickness of the frost layer is greater than or equal to the second thickness threshold, obtaining a second difference between the thickness of the frost layer and the second thickness threshold, and calculating using the second difference according to a preset algorithm to obtain the target speed. Wherein, the first thickness threshold is less than the second thickness threshold. In this way, when the thickness of the frost layer is greater than the second thickness threshold, not only the external defrosting device is controlled to heat the heat exchanger, but also the external fan is controlled to rotate, so that the air flow speed around the heat exchanger can be accelerated, thereby accelerating defrosting.

[0051] Optionally, the target speed is obtained by calculating the second difference according to a preset algorithm, including: F=n×2×R1+R2, where F is the target speed, n is the second difference, R1 is a preset speed correction value, and R2 is a preset initial speed.

[0052] In some embodiments, the second thickness threshold is 10 mm. The rotation speed correction value is 200 rpm. The initial rotation speed is 600 rpm. The target rotation speed is less than or equal to 2000 rpm.

[0053] Optionally, after the controller triggers the external defrost device to heat the heat exchanger, the process further includes: when the heat exchanger is not frosted, the controller controls the external defrost device to turn off.

[0054] Optionally, combined Figure 4 As shown, the defrosting system 100 further includes: a temperature detection device 106 and a humidity detection device 107. The temperature detection device 106 is electrically connected to the controller 102, and the temperature detection device 106 is used to detect and send the outdoor environment temperature to the controller 102. The humidity detection device 107 is electrically connected to the controller 102, and the humidity detection device 107 is used to detect and send the outdoor environment humidity to the controller 102. The outdoor environment temperature is the temperature of the area where the air conditioner outdoor unit is located. The outdoor environment humidity is the humidity of the area where the air conditioner outdoor unit is located.

[0055] Optionally, the controller is also used to send a frost detection instruction to the frost detection device when the outdoor ambient temperature is lower than a preset temperature and the outdoor ambient humidity is lower than a preset humidity. When the air conditioner is running in heating mode, the outdoor heat exchanger of the air conditioner absorbs heat from the air and reduces the surface temperature of the outdoor heat exchanger. At this time, if the outdoor ambient temperature is low and the outdoor ambient humidity is high, frost is likely to form on the surface of the outdoor heat exchanger. Therefore, by obtaining the frost condition of the heat exchanger only when the outdoor ambient temperature is lower than a preset temperature and the outdoor ambient humidity is lower than a preset humidity, unnecessary detection steps can be reduced.

[0056] Furthermore, the defrosting system further includes a first heat exchange device 108 and a second heat exchange device 109. The first heat exchange device 108 is connected to the second heat exchange device 109, and the first heat exchange device 108 is used to use a high-temperature and high-pressure refrigerant to perform heat exchange with an intermediate medium in the second heat exchange device 109. The second heat exchange device 109 stores an intermediate medium, and the second heat exchange device 109 is used to defrost the heat exchanger using the intermediate medium.

[0057] An embodiment of the present disclosure provides an air conditioner, comprising the above-mentioned system for defrosting.

[0058] Combination Figure 5 As shown, the embodiment of the present disclosure provides an air conditioner 200, including: a frost detection device 101, a controller 102, an external defrost device 103 and a heat exchanger 110. The frost detection device 101 is electrically connected to the controller 102, and the frost detection device 101 is used to detect and send the frost condition of the heat exchanger 110 to the controller 102. The controller 102 is electrically connected to the external defrost device 103, and the controller 102 is used to trigger the external defrost device 103 to heat the heat exchanger 110 when the frost condition is that the heat exchanger is frosted. The external defrost device 103 is used to heat the heat exchanger 110. Among them, the frost detection device 101 and the external defrost device 103 are both arranged on the heat exchanger 110.

[0059] The air conditioner provided by the embodiment of the present disclosure detects the frosting condition of the heat exchanger by using a frosting detection device, and controls the external defrosting device provided on the heat exchanger to heat the heat exchanger by using a controller when the heat exchanger is frosted, thereby directly heating the frost layer on the outer surface of the heat exchanger. Since there is no reversing flow of the refrigerant during the defrosting process, there is no need to re-establish the balance, thereby reducing the probability of indoor temperature fluctuations. This can provide users with an experience of using the air conditioner.

[0060] Combination Figure 6 As shown, the embodiment of the present disclosure provides an air conditioner 200, including: a compressor 201, a first heat exchange device 202, a second heat exchange device 203 and a heat exchanger 204. The compressor 201 is used to deliver refrigerant to the first heat exchange device 202 during operation, and receive the refrigerant flowing out of the first heat exchange device 202. The first heat exchange device 202 is connected to the second heat exchange device 203, and the first heat exchange device 202 is used to use the refrigerant to perform heat exchange with the intermediate medium in the second heat exchange device 203. The second heat exchange device 203 is arranged on the heat exchanger 204, and the intermediate medium is stored in the second heat exchange device 203. The second heat exchange device 203 is used to defrost the heat exchanger 204 using the intermediate medium.

[0061] With the air conditioner provided by the embodiment of the present disclosure, when the air conditioner is running, the refrigerant discharged from the compressor flows into the first heat exchange device to exchange heat with the intermediate medium in the second heat exchange device. Since the second heat exchange device is arranged on the heat exchanger and the refrigerant flowing out of the compressor is a high-temperature and high-pressure gas, when the refrigerant flows from the air conditioner into the first heat exchange device, the temperature of the intermediate medium in the second heat exchange device will rise accordingly, thereby achieving the effect of heating and defrosting the surface of the heat exchanger. In this process, the defrosting effect can be achieved without switching the operating state of the air conditioner, thereby reducing the fluctuation of the indoor temperature and improving the user's experience of using the air conditioner.

[0062] The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in the embodiment of the present disclosure. The aforementioned storage medium may be a non-transient storage medium, including: a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a disk or an optical disk, and other media that can store program codes, or a transient storage medium.

[0063] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent only possible changes. Unless explicitly required, separate components and functions are optional, and the order of operation may vary. The parts and features of some embodiments may be included in or replace the parts and features of other embodiments. Moreover, the words used in this application are only used to describe the embodiments and are not used to limit the claims. As used in the description of the embodiments and the claims, unless the context clearly indicates, the singular forms of "a", "an" and "the" are intended to include plural forms as well. Similarly, the term "and / or" as used in this application refers to any and all possible combinations of listings containing one or more associated ones. In addition, when used in the present application, the term "comprise" and its variants "comprises" and / or comprising refer to the presence of stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the presence of other identical elements in the process, method or device comprising the elements. In this article, each embodiment may focus on the differences from other embodiments, and the same and similar parts between the various embodiments may refer to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can refer to the description of the method part.

[0064] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software may depend on the specific application and design constraints of the technical solution. The technicians may use different methods for each specific application to implement the described functions, but such implementations should not be considered to exceed the scope of the embodiments of the present disclosure. The technicians may clearly understand that, for the convenience and simplicity of description, the specific working processes of the systems, devices and units described above may refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

[0065] In the embodiments disclosed herein, the disclosed methods and products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units can be only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to implement this embodiment. In addition, each functional unit in the embodiment of the present disclosure may be integrated in a processing unit, or each unit may exist physically alone, or two or more units may be integrated in one unit.

[0066] The flowchart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to the embodiment of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and the block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in a different order from the order disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A system for defrosting, characterized in that: include: A frost detection device, electrically connected to the controller, for detecting and sending frost conditions of the heat exchanger to the controller; A controller is electrically connected to the external defrost device, and the controller is used to trigger the external defrost device to heat the heat exchanger when the heat exchanger is frosted; The external defrost device is arranged on the heat exchanger and is used for heating the heat exchanger.

2. The system according to claim 1, characterized in that Also includes: The frost layer thickness detection device is electrically connected to the controller, and is used to detect and send the frost layer thickness of the heat exchanger to the controller.

3. The system according to claim 2, characterized in that The controller is also used to trigger the frost layer thickness detection device to detect the frost layer thickness on the heat exchanger when the frosting condition is that the heat exchanger is frosted.

4. The system according to claim 2, characterized in that The controller is also used to determine the heating temperature according to the thickness of the frost layer, and trigger the external defrosting device to heat the heat exchanger according to the heating temperature.

5. The system according to claim 4, characterized in that The controller determines the heating temperature according to the frost thickness in the following way: Determining a temperature correction value according to a first difference between the thickness of the frost layer and a preset first thickness threshold; The preset initial temperature is corrected using the temperature correction value to obtain the heating temperature.

6. The system according to claim 2, characterized in that Also includes: The external fan is electrically connected to the controller and is arranged at the rear of the air conditioner outdoor unit.

7. The system according to claim 6, characterized in that The controller is also used to determine a target speed according to the thickness of the frost layer, and trigger the external fan to rotate at the target speed.

8. The system according to claim 1, characterized in that Also includes: A temperature detection device is electrically connected to the controller, and is used to detect and send the outdoor ambient temperature to the controller; The humidity detection device is electrically connected to the controller, and is used to detect and send the outdoor environment humidity to the controller.

9. The system according to claim 8, characterized in that The controller is also used to trigger the frost detection device to detect the frost condition of the heat exchanger when the outdoor ambient temperature is lower than the set temperature and the outdoor ambient humidity is lower than the set humidity.

10. An air conditioner, characterized in that: A defrosting system comprising the system as claimed in any one of claims 1 to 9.

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