CN114659234A

CN114659234A - Method and device for defrosting of air conditioner and air conditioner

Info

Publication number: CN114659234A
Application number: CN202210187018.1A
Authority: CN
Inventors: 许磊; 张晓迪; 高强
Original assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Qingdao Haier Air Conditioning Electric Co Ltd; Haier Smart Home Co Ltd
Current assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Qingdao Haier Air Conditioning Electric Co Ltd; Haier Smart Home Co Ltd
Priority date: 2022-02-28
Filing date: 2022-02-28
Publication date: 2022-06-24
Anticipated expiration: 2042-02-28
Also published as: CN114659234B

Abstract

The application relates to the technical field of intelligent household appliances, and discloses a method for defrosting an air conditioner, which comprises the following steps: judging whether a first defrosting condition is met or not according to the outdoor environment temperature and the saturation temperature; judging whether a second defrosting condition is met or not according to the air outlet temperature of the indoor unit; the defrost mode is operated under conditions that satisfy both the first defrost condition and the second defrost condition. A first defrosting condition that can start a defrosting mode is determined by the outdoor environment temperature and the saturation temperature. And determining a second defrosting condition capable of starting the defrosting mode according to the air outlet temperature of the indoor unit of the air conditioner. In order to avoid the air conditioner from starting the defrosting mode by mistake when the outdoor unit is not frosted, the air conditioner is controlled to operate the defrosting mode when the two defrosting conditions are simultaneously met. Therefore, the accuracy of the defrosting mode is improved, and the heating operation stability of the air conditioner can be further ensured. The application also discloses a device and air conditioner that are used for the air conditioner defrosting.

Description

Method and device for defrosting of air conditioner and air conditioner

Technical Field

The application relates to the technical field of intelligent household appliances, in particular to a method and a device for defrosting an air conditioner and the air conditioner.

Background

At present, along with the popularization of air conditioners in daily life, the utilization rate of the air conditioners is gradually improved, the condition that the air conditioners need to be defrosted can appear in the process of heating operation in winter, and if defrosting operation is not carried out for a long time, the oil circulation of a refrigerating machine is not facilitated, and even the service life of a compressor can be influenced.

In the related technology, the defrosting control method comprises the steps of detecting the outdoor environment temperature, the outdoor heat exchanger temperature and the indoor unit air outlet temperature in real time, and comparing the outdoor environment temperature with a first threshold temperature; and executing a defrosting control mode corresponding to the comparison result according to the comparison result of the outdoor environment temperature and the first threshold temperature.

In the process of implementing the embodiments of the present disclosure, it is found that at least the following problems exist in the related art:

under the condition that an outdoor unit is not frosted, the air conditioner frequently operates in a defrosting mode due to the fact that detection of a defrosting sensor has errors, and therefore the stability of heating operation of the air conditioner is poor.

Disclosure of Invention

The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview and is intended to neither identify key/critical elements nor delineate the scope of such embodiments, but is intended to be a prelude to the more detailed description that is presented later.

The embodiment of the disclosure provides a method and a device for defrosting an air conditioner and the air conditioner, so as to improve the accuracy of an operation defrosting mode and further ensure the stability of the heating operation of the air conditioner.

In some embodiments, the above method comprises: judging whether a first defrosting condition is met or not according to the outdoor environment temperature and the saturation temperature; judging whether a second defrosting condition is met or not according to the air outlet temperature of the indoor unit; the defrost mode is operated under conditions that satisfy both the first defrost condition and the second defrost condition.

In some embodiments, the apparatus comprises: a processor and a memory storing program instructions, the processor being configured to, upon execution of the program instructions, perform the above-described method for defrosting an air conditioner.

In some embodiments, the air conditioner includes: the device for defrosting the air conditioner is disclosed.

The method and the device for defrosting the air conditioner and the air conditioner provided by the embodiment of the disclosure can realize the following technical effects:

a first defrosting condition that can start a defrosting mode is determined by the outdoor environment temperature and the saturation temperature. And determining a second defrosting condition capable of starting the defrosting mode according to the air outlet temperature of the indoor unit of the air conditioner. In order to avoid that the air conditioner is wrongly started to a defrosting mode under the condition that the outdoor unit is not frosted when a single condition is met, the air conditioner is controlled to operate the defrosting mode under the condition that the two defrosting conditions are simultaneously met. Therefore, the accuracy of the operation defrosting mode is effectively improved, and the stability of the heating operation of the air conditioner can be further ensured.

The foregoing general description and the following description are exemplary and explanatory only and are not restrictive of the application.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the accompanying drawings and not in limitation thereof, in which elements having the same reference numeral designations are shown as like elements and not in limitation thereof, and wherein:

FIG. 1 is a schematic diagram of a method for defrosting an air conditioner according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram of another method for defrosting an air conditioner provided by an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of another method for defrosting an air conditioner provided by an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of another method for defrosting an air conditioner provided by an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of another method for defrosting an air conditioner provided by an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of another method for defrosting an air conditioner provided by an embodiment of the present disclosure;

fig. 7 is a schematic diagram of an apparatus for defrosting an air conditioner according to an embodiment of the present disclosure.

Detailed Description

So that the manner in which the features and advantages of the embodiments of the present disclosure can be understood in detail, a more particular description of the embodiments of the disclosure, briefly summarized above, may be had by reference to the appended drawings, which are included to illustrate, but are not intended to limit the embodiments of the disclosure. In the following description of the technology, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the disclosed embodiments. However, one or more embodiments may be practiced without these details. In other instances, well-known structures and devices may be shown in simplified form in order to simplify the drawing.

The terms "first," "second," and the like in the description and in the claims, and the above-described drawings of embodiments of the present disclosure, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the present disclosure described herein may be made. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion.

The term "plurality" means two or more unless otherwise specified.

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 represents: a or B.

The term "and/or" is an associative relationship that describes objects, meaning that three relationships may exist. E.g., a and/or B, represents: a or B, or A and B.

The term "correspond" may refer to an association or binding relationship, and a corresponds to B refers to an association or binding relationship between a and B.

In the embodiment of the disclosure, the intelligent household appliance is a household appliance formed by introducing a microprocessor, a sensor technology and a network communication technology into the household appliance, and has the characteristics of intelligent control, intelligent sensing and intelligent application, the operation process of the intelligent household appliance usually depends on the application and processing of modern technologies such as internet of things, internet and an electronic chip, for example, the intelligent household appliance can realize the remote control and management of a user on the intelligent household appliance by connecting the intelligent household appliance with the electronic device.

Referring to fig. 1, an embodiment of the present disclosure provides a method for defrosting an air conditioner, including:

and S01, the air conditioner judges whether the first defrosting condition is met according to the outdoor environment temperature and the saturation temperature.

And S02, the air conditioner judges whether the second defrosting condition is met according to the air outlet temperature of the indoor unit.

S03, the air conditioner operates the defrost mode if the first defrost condition and the second defrost condition are simultaneously satisfied.

By adopting the defrosting method for the air conditioner provided by the embodiment of the disclosure, a first defrosting condition which can start a defrosting mode can be determined according to the outdoor environment temperature and the saturation temperature. And determining a second defrosting condition capable of starting the defrosting mode according to the air outlet temperature of the indoor unit of the air conditioner. In order to avoid that the air conditioner starts the defrosting mode by mistake under the condition that the outdoor unit is not frosted when a single condition is met, the air conditioner is controlled to operate the defrosting mode under the condition that the two defrosting conditions are met simultaneously. Therefore, the accuracy of the operation defrosting mode is effectively improved, and the stability of the heating operation of the air conditioner can be further ensured.

Referring to fig. 2, another method for defrosting an air conditioner according to an embodiment of the present disclosure includes:

and S011, under the condition that the air conditioner operates to a stable state, the air conditioner acquires an initial saturation temperature.

And S012, acquiring the current saturation temperature by the air conditioner under the condition that the stable operation time length of the air conditioner is greater than or equal to a first set time length.

And S013, calculating a saturation temperature difference value by the air conditioner according to the initial saturation temperature and the current saturation temperature.

And S014, judging whether the first defrosting condition is met or not by the air conditioner according to the difference value between the outdoor environment temperature and the saturation temperature.

By adopting the defrosting method for the air conditioner, the calculation accuracy of the saturation temperature difference can be improved to the maximum extent, so that the accuracy of the operation defrosting mode is improved. The air conditioner starts the defrosting mode under the condition that the outdoor heat exchanger is not frosted because the air conditioner can cause wrong calculation of the saturation temperature difference under the condition that the air conditioner is not operated stably. Therefore, whether the air conditioner reaches a stable operation state is determined by limiting the operation time period of the air conditioner, thereby ensuring the accuracy of the calculation of the saturation temperature difference. In addition, the current state of the air conditioner can also be determined by presetting the stability of the running power of the compressor, the rotating speed of the fan or the temperature of the outlet air.

Alternatively, in the case that the air conditioner is operated to the steady state, if the air conditioner has an oil return phenomenon or a load transition phenomenon, after the oil return phenomenon or the load transition phenomenon is completed, the air conditioner obtains a new initial saturation temperature.

Therefore, the accuracy of calculation of the saturation temperature difference can be better ensured. The air conditioner may be considered to be unstable in operation because the saturation temperature of the air conditioner may vary during oil return or load conversion. In order to avoid influencing the value of the saturation temperature, the accuracy of the defrosting mode of the air conditioner is further influenced. Therefore, after oil return or load conversion is completed, the air conditioner obtains a new initial saturation temperature, and value determination is carried out again according to the method so as to ensure the accuracy of calculation of the saturation temperature difference.

Optionally, the determining, by the air conditioner, whether the first defrosting condition is satisfied according to a difference between the outdoor ambient temperature and the saturation temperature includes: the air conditioner determines a corresponding saturation temperature difference threshold value and a first time length threshold value according to the outdoor environment temperature; and under the condition that the duration of the saturation temperature difference value which is continuously less than or equal to the saturation temperature difference threshold value is greater than a first duration threshold value, the air conditioner judges that a first defrosting condition is met.

Therefore, the accuracy of the operation defrosting mode can be better improved, and the stability of the heating operation of the air conditioner is further ensured. For example, in the case where the outdoor ambient temperature is greater than or equal to 6 ℃, the temperature difference threshold is determined to be 15 ℃ and the first time length threshold is determined to be 5 minutes. That is, in the case that the outdoor ambient temperature is greater than or equal to 6 ℃, if the saturation temperature difference is continuously less than or equal to 15 ℃ within 5 minutes, it is determined that the air conditioner satisfies the first defrosting condition. And under the condition that the outdoor environment temperature is greater than or equal to-15 ℃ and less than 6 ℃, determining that the temperature difference threshold is 15 ℃ and the first time length threshold is 10 minutes. And under the condition that the outdoor environment temperature is greater than or equal to-23 ℃ and less than-15 ℃, determining that the temperature difference threshold is 8 ℃ and the first time length threshold is 10 minutes. And under the condition that the outdoor environment temperature is lower than-23 ℃, determining that the temperature difference threshold is 5 ℃ and the first time length threshold is 10 minutes.

Referring to fig. 3, another method for defrosting an air conditioner is provided in an embodiment of the present disclosure, including:

And S04, in the case that the difference between the time meeting the second defrosting condition and the time meeting the first defrosting condition is larger than the set time difference threshold, the air conditioner corrects the saturation temperature difference threshold.

By adopting the method for defrosting the air conditioner, the problem that due to the fact that errors occur in the judgment of the first defrosting condition, defrosting is not started for a long time, and the service life of the air conditioner is further influenced can be avoided. Specifically, under the condition that the current air outlet temperature difference value of the air conditioner is continuously less than or equal to 10 ℃ within 20 minutes, the saturation temperature difference value at the time just meets the condition that the saturation temperature difference value is less than or equal to the saturation temperature difference threshold value (namely, the outdoor environment temperature is greater than or equal to-23 ℃ and less than-15 ℃, the temperature difference threshold value is determined to be 8 ℃, and the first time length threshold value is 10 minutes). It is required to ensure that the air conditioner operates in the defrost mode after the saturation temperature difference of the air conditioner continues to be less than or equal to 8 c for 10 minutes. Because the duration is too long, in order to prevent serious frosting or the air conditioner reports low-voltage faults, the saturation temperature difference threshold is corrected (reduced by 1 ℃). Under the condition that the current air outlet temperature difference of the air conditioner is continuously less than or equal to 10 ℃ within 20 minutes, and the saturation temperature difference is not less than or equal to the saturation temperature difference threshold after 10 minutes, correcting the saturation temperature difference threshold (reducing by 1 ℃).

Referring to fig. 4, another method for defrosting an air conditioner according to an embodiment of the present disclosure includes:

and S015, under the condition that the air conditioner operates to a stable state, the air conditioner acquires an initial air outlet temperature.

And S016, when the time length of the stable operation of the air conditioner is greater than or equal to a second set time length, the air conditioner acquires the current air outlet temperature.

And S017, calculating an air outlet temperature difference value by the air conditioner according to the initial air outlet temperature and the current air outlet temperature.

And S018, judging whether a second defrosting condition is met or not by the air conditioner according to the air outlet temperature difference value.

And S03, the air conditioner operates the defrost mode if the first defrost condition and the second defrost condition are simultaneously satisfied.

By adopting the method for defrosting the air conditioner, the accuracy of calculation of the air outlet temperature difference can be improved to the maximum extent, so that the accuracy of the operation defrosting mode is improved. The air conditioner starts the defrosting mode under the condition that the outdoor heat exchanger is not frosted because the air conditioner can wrongly calculate the air outlet temperature difference under the condition that the air conditioner is unstable in operation. Therefore, whether the air conditioner reaches a stable operation state is determined by limiting the operation time of the air conditioner, and the accuracy of the calculation of the outlet air temperature difference is ensured. In addition, the current state of the air conditioner can also be determined by presetting the stability of the running power of the compressor, the rotating speed of the fan or the temperature of the outlet air.

Optionally, in a case that the air conditioner is operated to a stable state, if an oil return phenomenon or a load transition phenomenon occurs in the air conditioner, after the oil return phenomenon or the load transition phenomenon is completed, the air conditioner obtains a new initial outlet air temperature.

Therefore, the accuracy of calculating the air outlet temperature difference can be better ensured. The air conditioner is considered to be unstable in operation because the air outlet temperature of the air conditioner changes in the process of oil return or load conversion. In order to avoid influencing the value of the air outlet temperature, the accuracy of the defrosting mode of the air conditioner is further influenced. Therefore, after oil return or load conversion is completed, the air conditioner obtains a new initial air outlet temperature, and value determination is carried out again according to the method so as to ensure the accuracy of air outlet temperature difference calculation.

Optionally, the air conditioner determines whether a second defrosting condition is satisfied according to the outlet air temperature difference, including: and under the condition that the duration of the air outlet temperature difference value which is continuously smaller than the preset temperature threshold value is larger than a second duration threshold value, the air conditioner judges that a second defrosting condition is met.

Therefore, the accuracy of the operation defrosting mode can be better improved, and the stability of the heating operation of the air conditioner is further ensured. Specifically, if the outlet air temperature difference is continuously less than or equal to 10 ℃ within 20 minutes, it is determined that the air conditioner meets the second defrosting condition.

Referring to fig. 5, another method for defrosting an air conditioner according to an embodiment of the present disclosure includes:

And S05, reducing the fan speed of the indoor unit and correcting the preset temperature threshold value by the air conditioner under the condition that the time meeting the second defrosting condition is earlier than the time meeting the first defrosting condition.

By adopting the method for defrosting the air conditioner, the condition that the air conditioner releases cold air under the condition that the time of the second defrosting condition is earlier than the time of meeting the first defrosting condition can be avoided. And controlling the rotating speed of the fan of the indoor unit to be reduced under the condition that the second defrosting condition is met. And under the condition that the air conditioner meets the first defrosting condition, correcting the preset temperature threshold.

Referring to fig. 6, another method for defrosting an air conditioner according to an embodiment of the present disclosure includes:

and S06, the air conditioner acquires the pressure value at the exhaust pipe.

And S07, the air conditioner determines the corresponding saturation temperature according to the pressure value.

By adopting the defrosting method for the air conditioner provided by the embodiment of the disclosure, the corresponding pressure value can be obtained through the high-pressure sensor arranged at the exhaust pipe of the air conditioner. And determining the saturation temperature corresponding to the pressure value according to the preset corresponding relation. Or according to the preset calculation logic, calculating the corresponding saturation temperature through the pressure value.

As shown in fig. 7, an embodiment of the present disclosure provides an apparatus for defrosting an air conditioner, which includes a processor (processor)100 and a memory (memory) 101. Optionally, the apparatus may also include a Communication Interface (Communication Interface)102 and a bus 103. The processor 100, the communication interface 102, and the memory 101 may communicate with each other via a bus 103. The communication interface 102 may be used for information transfer. The processor 100 may call logic instructions in the memory 101 to perform the method for defrosting an air conditioner of the above-described embodiment.

In addition, the logic instructions in the memory 101 may be implemented in the form of software functional units and stored in a computer readable storage medium when the logic instructions are sold or used as independent products.

The memory 101, which is a computer-readable storage medium, may be used for storing software programs, computer-executable programs, such as program instructions/modules corresponding to the methods in the embodiments of the present disclosure. The processor 100 executes functional applications and data processing by executing program instructions/modules stored in the memory 101, that is, implements the method for defrosting an air conditioner in the above-described embodiment.

The memory 101 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created according to the use of the terminal device, and the like. In addition, memory 101 may include high speed random access memory and may also include non-volatile memory.

The embodiment of the disclosure provides an air conditioner, which comprises the device for defrosting the air conditioner.

Embodiments of the present disclosure provide a storage medium storing computer-executable instructions configured to perform the above-described method for defrosting an air conditioner.

The storage medium may be a transitory storage medium or a non-transitory storage medium.

The technical solution of the embodiments of the present disclosure may be embodied in the form of a software product, where the computer software product is stored in a storage medium and includes one or more instructions to enable a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method of the embodiments of the present disclosure. And the aforementioned storage medium may be a non-transitory storage medium comprising: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes, and may also be a transient storage medium.

The above description and the drawings sufficiently illustrate embodiments of the disclosure to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. The examples merely typify possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in or substituted for those of others. Furthermore, the words used in the specification are words of description only and are not intended to limit the claims. As used in the description of the embodiments and the claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Similarly, the term "and/or" as used in this application is meant to encompass any and all possible combinations of one or more of the associated listed. Furthermore, the terms "comprises" and/or "comprising," when used in this application, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Without further limitation, an element defined by the phrase "comprising an …" does not exclude the presence of other like elements in a process, method or apparatus that comprises the element. In this document, each embodiment may be described with emphasis on differences from other embodiments, and the same and similar parts between the respective embodiments may be referred to each other. For methods, products, etc. of the embodiment disclosures, reference may be made to the description of the method section for relevance if it corresponds to the method section of the embodiment disclosure.

Those of skill in the art would appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software may depend upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the disclosed embodiments. It can be clearly understood by the skilled person that, for convenience and simplicity of description, the specific working processes of the above-described systems, apparatuses, and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the embodiments disclosed herein, the disclosed methods, products (including but not limited to devices, apparatuses, etc.) may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units may be merely a logical division, and in actual implementation, there may be another division, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form. The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to implement the present embodiment. In addition, functional units in the embodiments of the present disclosure may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. In the description corresponding to the flowcharts and block diagrams in the figures, operations or steps corresponding to different blocks may also occur in different orders than disclosed in the description, and sometimes there is no specific order between the different operations or steps. For example, two sequential operations or steps may in fact be executed substantially concurrently, or they may sometimes be executed in the reverse order, depending upon the functionality involved. Each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

Claims

1. A method for defrosting an air conditioner, comprising:

judging whether a first defrosting condition is met or not according to the outdoor environment temperature and the saturation temperature;

judging whether a second defrosting condition is met or not according to the air outlet temperature of the indoor unit;

operating a defrost mode if the first defrost condition and the second defrost condition are simultaneously satisfied.

2. The method of claim 1, wherein determining whether a first defrost condition is satisfied based on the outdoor ambient temperature and the saturation temperature comprises:

acquiring an initial saturation temperature under the condition that the air conditioner operates to a stable state;

under the condition that the stable operation time of the air conditioner is longer than or equal to a first set time, acquiring the current saturation temperature;

calculating a saturation temperature difference value according to the initial saturation temperature and the current saturation temperature;

and judging whether a first defrosting condition is met or not according to the difference value between the outdoor environment temperature and the saturation temperature.

3. The method of claim 2, wherein said determining whether a first defrost condition is satisfied based on the difference between the outdoor ambient temperature and the saturation temperature comprises:

determining a corresponding saturation temperature difference threshold value and a first time length threshold value according to the outdoor environment temperature;

and under the condition that the duration of the saturation temperature difference value which is continuously less than or equal to the saturation temperature difference threshold value is greater than a first duration threshold value, determining that the air conditioner meets a first defrosting condition.

4. The method of claim 3, further comprising, after said determining whether a second defrost condition is met:

and under the condition that the time difference value between the time meeting the second defrosting condition and the time meeting the first defrosting condition is greater than a set time difference threshold value, correcting the saturated temperature difference threshold value.

5. The method of claim 1, wherein the determining whether the second defrosting condition is satisfied according to the outlet air temperature of the indoor unit comprises:

acquiring an initial air outlet temperature under the condition that the air conditioner operates to a stable state;

acquiring the current air outlet temperature under the condition that the time length of the air conditioner in stable operation is greater than or equal to a second set time length;

calculating an air outlet temperature difference value according to the initial air outlet temperature and the current air outlet temperature;

and judging whether a second defrosting condition is met or not according to the air outlet temperature difference.

6. The method according to claim 5, wherein the determining whether a second defrosting condition is satisfied according to the outlet air temperature difference includes:

and under the condition that the duration of the air outlet temperature difference value which is continuously smaller than the preset temperature threshold value is larger than a second duration threshold value, judging that the air conditioner meets a second defrosting condition.

7. The method of claim 6, after determining that the air conditioner satisfies the second defrost condition, further comprising:

and under the condition that the time meeting the second defrosting condition is earlier than the time meeting the first defrosting condition, reducing the rotating speed of a fan of the indoor unit and correcting the preset temperature threshold.

8. The method of any of claims 1 to 7, further comprising, before said determining whether a first defrost condition is satisfied based on the outdoor ambient temperature and the saturation temperature:

acquiring a pressure value at the exhaust pipe;

and determining the corresponding saturation temperature according to the pressure value.

9. An apparatus for defrosting an air conditioner comprising a processor and a memory having stored thereon program instructions, wherein the processor is configured to perform the method for defrosting an air conditioner according to any one of claims 1 to 8 when executing the program instructions.

10. An air conditioner characterized by comprising the device for defrosting an air conditioner according to claim 9.