CN115183401B

CN115183401B - Air conditioner and defrosting control method thereof

Info

Publication number: CN115183401B
Application number: CN202210760711.3A
Authority: CN
Inventors: 张素珍
Original assignee: Hisense Air Conditioning Co Ltd
Current assignee: Hisense Air Conditioning Co Ltd
Priority date: 2022-06-30
Filing date: 2022-06-30
Publication date: 2023-07-14
Anticipated expiration: 2042-06-30
Also published as: CN115183401A

Abstract

The invention discloses an air conditioner and a defrosting control method of the air conditioner, wherein the air conditioner comprises a compressor, an outdoor heat exchanger, a temperature sensor and a controller, wherein the temperature sensor is used for detecting the temperature of an outdoor coil; the controller is configured to: when the air conditioner heats and operates, the operation frequency of the compressor is obtained, the increase value of the operation frequency in a preset period is determined to exceed a preset frequency threshold value, and the air conditioner is controlled to enter a false defrosting mode; in the pseudo defrosting mode, acquiring the temperature of an outdoor coil, determining that the temperature of the outdoor coil at the (n+1) th moment is smaller than the temperature of the outdoor coil at the n th moment, controlling the air conditioner to keep heating operation so as not to carry out outdoor defrosting, limiting that the temperature of the outdoor environment does not meet the condition of entering the conventional defrosting mode, further continuously determining that the temperature of the outdoor coil at the (m+1) th moment is not lower than the temperature of the outdoor coil at the m th moment for a first preset time, and controlling the air conditioner to continuously keep heating operation, wherein m and n are natural numbers, and the first preset time is more than or equal to 2 times.

Description

Air conditioner and defrosting control method thereof

Technical Field

The invention relates to the technical field of air conditioners, in particular to an air conditioner and a defrosting control method of the air conditioner.

Background

When outdoor ambient temperature is lower in winter, when the air conditioner runs the heating mode for a long time, the outdoor unit of the air conditioner is easy to frost on the evaporation side, and then the heating effect is reduced, and as the frost layer is thicker along with the increase of the frosting time, the heat transfer resistance of the outdoor unit of the air conditioner can be increased by the frost layer, so that the outdoor air circulation area is reduced, the flow resistance is increased, the air quantity of the outdoor unit is reduced, the outdoor evaporation temperature is further reduced, the heat exchange is poor, the indoor ambient comfort is reduced, the user requirements cannot be met, and the user experience is reduced. Thus, after the air conditioner is operated for a certain period of time, it is required to defrost the air conditioner timely and effectively. The current defrosting technology mainly comprises refrigeration mode (reverse circulation) defrosting, bypass defrosting and phase change energy storage defrosting.

Air conditioners commonly employ a cooling mode (reverse cycle) for defrosting, and in the related art, the cooling mode is performed using an outdoor ring temperature Tout and an outdoor heat exchange temperature difference ΔtoutDetermining whether a defrost condition is satisfied, wherein an outdoor heat exchange temperature difference Δtout=an outdoor ambient temperature tout—an outdoor coil temperature T _{Outer disc} . In this way, on the occasion of entering the normal defrosting mode, for some special scenes such as an increase in indoor temperature difference or an increase in indoor wind speed, an abrupt increase in the operating frequency F occurs so that T _{Outer disc} The outdoor heat exchange temperature difference delta Tout suddenly increases to meet the defrosting condition and enters the conventional defrosting mode. However, at this time, there is no or very thin frost on the outdoor heat exchanger, the heating capacity is very strong, the defrosting mode is performed, which causes a great fluctuation in room temperature, reduces user comfort, and consumes additional energy.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, one of the purposes of the present invention is to provide an air conditioner, which can effectively avoid the phenomena of defrosting without frost and frequent defrosting, avoid extra energy consumption, and ensure the experience of users.

The second objective of the present invention is to provide a defrosting control method for an air conditioner.

In order to achieve the above object, an air conditioner according to an embodiment of a first aspect of the present invention includes: a compressor and an outdoor heat exchanger; the temperature sensor is arranged on the outdoor heat exchanger and is used for detecting the temperature of the outdoor coil; a controller coupled to the compressor and the temperature sensor, the controller configured to: when the air conditioner heats and operates, the operation frequency of the compressor is obtained, the increase value of the operation frequency in a preset period is determined to exceed a preset frequency threshold value, and the air conditioner is controlled to enter a false defrosting mode; and under the pseudo defrosting mode, acquiring the outdoor coil temperature, determining that the outdoor coil temperature at the (n+1) th moment is smaller than the outdoor coil temperature at the n th moment, controlling the air conditioner to keep heating operation so as not to carry out outdoor defrosting, limiting that the outdoor environment temperature does not meet the condition of entering the conventional defrosting mode, further continuously determining that the outdoor coil temperature at the (m+1) th moment is not lower than the outdoor coil temperature at the m th moment for a first preset number of times, and controlling the air conditioner to keep heating operation continuously, wherein m and n are natural numbers, and the first preset number of times is more than or equal to 2.

According to the air conditioner provided by the embodiment of the invention, a false defrosting mode is provided, and the air conditioner is controlled to enter the false defrosting mode by detecting the operating frequency of the compressor and determining that the increased value of the operating frequency of the compressor in a preset period exceeds a preset frequency threshold value. The temperature sensor is used for acquiring the temperature of the outdoor coil, and further can provide data reference for the current operation strategy of the air conditioner. The phenomenon of defrosting without frost and frequent defrosting can be effectively avoided under the unsteady state that the temperature of the outdoor coil is changed due to the change of the operation frequency of the compressor, and the control is more accurate. And when the temperature of the outdoor coil begins to rise or tends to be stable in the unstable state of the system, the air conditioner is controlled to keep heating operation, the control of the exit condition of the false defrosting mode is more accurate, and the user experience is improved.

In some embodiments of the invention, in the false defrost mode, the controller is further configured to: the method includes the steps of recording an operating frequency of a compressor at a time when an outdoor coil temperature at an (m+1) th time is determined to be not lower than an outdoor coil temperature at an m-th time continuously a first preset number of times as a first frequency, starting from a time when an outdoor coil temperature at an (m+1) th time is determined to be not lower than an outdoor coil temperature at an m-th time continuously a first preset number of times, further determining that the outdoor coil temperature remains unchanged or determining that the outdoor coil temperature at an (i+1) th time is less than the outdoor coil temperature at an i-th time and the operating frequency of the compressor is not greater than the first frequency, controlling the air conditioner to exit the pseudo defrosting mode, continuing a heating operation, and canceling limitation of the outdoor environment temperature, wherein the second preset number of times is not less than 2 times and i > m.

According to the air conditioner provided by the embodiment of the invention, the temperature of the outdoor coil and the running frequency of the compressor are detected, after the fact that the air conditioning system fluctuates and tends to be stable is determined, the air conditioner is timely controlled to exit the false defrosting mode to run the conventional heating mode, so that extra energy consumption is avoided, the experience of a user is ensured, and the requirement of the user on the comfort degree under the heating working condition is met.

In some embodiments of the invention, the controller is further configured to, upon determining that the outdoor coil temperature at time (i+1) is less than the outdoor coil temperature at time i, continuously determine a second preset number of times that the outdoor coil temperature meets the outdoor coil temperature at time (i+1) less than the outdoor coil temperature at time i, wherein the second preset number of times is ∈2.

In some embodiments of the invention, the controller is further configured to: after determining that the outdoor coil temperature at the (n+1) th time is less than the outdoor coil temperature at the n-th time, further determining that the outdoor coil temperature rises again, the outdoor coil temperature remains unchanged after rising to a first temperature, and the duration of the outdoor coil temperature remaining unchanged after reaching the first time is reduced again to a second temperature, and the operating frequency of the compressor is increased to a second frequency unchanged, controlling the air conditioner to defrost outdoors and canceling the limitation of the outdoor environment temperature, wherein the second temperature reaches a defrost temperature.

In some embodiments of the present invention, the controller is further configured to determine that the air conditioner is in heating operation when the air conditioner is detected to start the heating mode and the continuous operation time reaches a first preset duration, wherein 10min is less than or equal to the first preset duration.

In order to achieve the above object, a defrosting control method for an air conditioner according to a second aspect of the present invention includes: detecting the heating operation of the air conditioner, and acquiring the operation frequency of the compressor; determining that the increased value of the running frequency in a preset period exceeds a preset frequency threshold value, and controlling the air conditioner to enter a false defrosting mode; acquiring the outdoor coil temperature from the moment of entering the pseudo defrosting mode, determining that the outdoor coil temperature at the (n+1) th moment is smaller than the outdoor coil temperature at the nth moment, controlling the air conditioner to keep heating operation so as not to perform outdoor defrosting, and limiting that the outdoor environment temperature does not meet the condition of entering the conventional defrosting mode, wherein n is a natural number; further continuously determining that the temperature of the outdoor coil meets the temperature of the outdoor coil at the (m+1) th moment and is not lower than the temperature of the outdoor coil at the m th moment for a first preset number of times, and controlling the air conditioner to continuously keep heating operation, wherein m is a natural number, and the first preset number of times is more than or equal to 2 times.

According to the defrosting control method of the air conditioner, a false defrosting mode is provided, and the air conditioner is controlled to enter the false defrosting mode by detecting the operating frequency of the compressor and determining that the increased value of the operating frequency of the compressor in a preset period exceeds a preset frequency threshold value. And by acquiring the outdoor coil temperature, a data reference can be provided for the current operation strategy of the air conditioner. The phenomenon of defrosting without frost and frequent defrosting can be effectively avoided under the unsteady state that the temperature of the outdoor coil is changed due to the change of the operation frequency of the compressor, and the control is more accurate. And when the temperature of the outdoor coil begins to rise or tends to be stable in the unstable state of the system, the air conditioner is controlled to keep heating operation, the control of the exit condition of the false defrosting mode is more accurate, and the user experience is improved.

In some embodiments of the present invention, after further continuously determining that the outdoor coil temperature satisfies the outdoor coil temperature at the (m+1) th time not lower than the outdoor coil temperature at the m-th time a first preset number of times, the control method further includes: recording an operating frequency of the compressor at a time when the outdoor coil temperature at the (m+1) th time is determined not to be lower than the outdoor coil temperature at the m-th time continuously a first preset number of times as a first frequency; further determining that the outdoor coil temperature remains unchanged or that the outdoor coil temperature at the (i+1) th time is less than the outdoor coil temperature at the i th time and the operating frequency of the compressor is not greater than the first frequency from a time when the outdoor coil temperature at the (m+1) th time is not less than the outdoor coil temperature at the m th time continuously a first preset number of times, wherein i > m, the second preset number of times is not less than 2 times; and controlling the air conditioner to exit the pseudo defrosting mode, continuing heating operation, and canceling limitation on the outdoor environment temperature.

According to the defrosting control method for the air conditioner, provided by the embodiment of the invention, the air conditioner is timely controlled to exit the false defrosting mode to operate the conventional heating mode after the fluctuation and the stability of the air conditioning system are determined by detecting the temperature of the outdoor coil pipe and the operation frequency of the compressor, so that the extra consumption of energy is avoided, the experience of a user is ensured, and the requirement of the user on the comfort degree under the heating working condition is met.

In some embodiments of the present invention, determining that the outdoor coil temperature at time (i+1) is less than the outdoor coil temperature at time i comprises: and continuously determining that the outdoor coil temperature meets the requirement that the outdoor coil temperature at the (i+1) time is smaller than the outdoor coil temperature at the i time for a second preset time, wherein the second preset time is more than or equal to 2 times.

In some embodiments of the invention the method further comprises: after determining that the outdoor coil temperature at the (n+1) th time is less than the outdoor coil temperature at the n-th time, further determining that the outdoor coil temperature rises again, the outdoor coil temperature remains unchanged after rising to a first temperature, and the duration of the outdoor coil temperature remaining unchanged after reaching the first time is reduced again to a second temperature, and the operating frequency of the compressor is increased to a second frequency unchanged, controlling the air conditioner to defrost outdoors and canceling the limitation of the outdoor environment temperature, wherein the second temperature reaches a defrost temperature.

In some embodiments of the present invention, detecting the heating operation of the air conditioner includes: detecting that the air conditioner starts to operate a heating mode and the continuous operation time reaches a first preset duration, wherein 10min is less than or equal to the first preset duration.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic view of an air conditioner;

fig. 2 is a block diagram of an air conditioner according to an embodiment of the present invention;

FIG. 3 is a schematic view showing an outdoor unit coil temperature affected by an operating frequency of a compressor according to an embodiment of the present invention;

fig. 4 is a flowchart of a defrosting control method of an air conditioner according to an embodiment of the present invention;

fig. 5 is a flowchart of a defrosting control method of an air conditioner according to another embodiment of the present invention;

fig. 6 is a flowchart of a defrosting control method of an air conditioner according to still another embodiment of the present invention;

fig. 7 is a flowchart of a defrosting control method of an air conditioner according to still another embodiment of the present invention;

Fig. 8 is a flowchart of a defrosting control method of an air conditioner according to still another embodiment of the present invention.

Reference numerals:

an air conditioner 10;

a compressor 1, an outdoor heat exchanger 2, a temperature sensor 3, and a controller 4.

Detailed Description

Embodiments of the present invention will be described in detail below, by way of example with reference to the accompanying drawings.

The current defrosting technology mainly comprises refrigeration mode (reverse circulation) defrosting, bypass defrosting and phase change energy storage defrosting. When defrosting is carried out in a refrigeration mode, the indoor heat exchanger is used as an evaporation end, so that the indoor ring temperature is obviously reduced, the heating effect of the air conditioner is affected, and the comfort experience of a user is affected. But adopts a reverse circulation mode without other complex components, and has the advantages of simple system, mature technology, low cost and the like. When the bypass defrosting mode is adopted, the refrigerant can continuously enter the air conditioner internal unit to heat, so that the air conditioner can still maintain the heating working condition without changing the heating cycle of the unit, and the defrosting purpose is achieved by utilizing the heat released by exhaust. Therefore, the bypass defrosting mode can ensure indoor comfort relative to reverse circulation defrosting. But the hot gas bypass defrosting time is longer and is more than 2 times of reverse circulation defrosting time. The phase change heat storage defrosting, reverse circulation defrosting and bypass defrosting all have the problem that the heat source is not enough, and heat storage defrosting is under the heating mode, stores partial heat, and when need defrosting, is giving out heat, adopts the mode of parcel compressor to carry out energy storage often, but under the cooling mode in summer, influences the press heat dissipation, easily leads to exhaust temperature too high, and the accumulator energy storage is limited simultaneously, does not generally use at present.

The prior air conditioner generally adopts a refrigeration mode (reverse circulation) defrosting, and in order to ensure that the heating efficiency of the indoor environment is not affected, the outdoor unit should be timely and effectively defrosted, and defrosting or excessive frosting caused by no frost is avoided. When the refrigeration mode is adopted for defrosting, the indoor heat exchanger is used as the evaporation end, so that the indoor ring temperature is obviously reduced, the heating effect of the air conditioner is affected, and the comfort experience of a user is affected. Particularly, in some special situations, such as a sudden increase in the operating frequency of the compressor, the temperature of the outdoor coil drops rapidly, so that the outdoor heat exchange temperature difference Δtout increases suddenly to meet the defrosting condition and enter defrosting. However, since there is no or very thin frost on the outdoor heat exchanger at this time, the heating capacity is very strong, the defrosting mode is performed, which causes a great fluctuation in room temperature, reduces user comfort, and also consumes additional energy.

Based on the above, in order to solve the problem that the temperature of an outdoor coil pipe is rapidly reduced due to the fact that the operation frequency of a compressor suddenly rises, so that the outdoor heat exchange temperature difference delta Tout suddenly increases to meet the defrosting condition, and then the air conditioner is frostless to defrost, the embodiment of the invention provides an air conditioner defrosting control method and an air conditioner adopting the method.

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

Fig. 1 is a schematic view of an air conditioner, in which a basic structure of the air conditioner can be understood in conjunction with fig. 1, and in this application the air conditioner performs a cooling/heating cycle of the air conditioner by using a compressor, a condenser, an expansion valve, and an evaporator. Among them, the refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation, and supplies a refrigerant to air that has been conditioned and heat-exchanged.

The compressor compresses refrigerant gas in a high-temperature and high-pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

The expansion valve expands the liquid-phase refrigerant in a high-temperature and high-pressure state condensed in the condenser into a low-pressure liquid-phase refrigerant. The evaporator evaporates the refrigerant expanded in the expansion valve and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor. The evaporator may achieve a cooling effect by exchanging heat with a material to be cooled using latent heat of evaporation of a refrigerant. The air conditioner may adjust the temperature of the indoor space throughout the cycle.

The outdoor unit of the air conditioner refers to a portion of the system cycle including a compressor and an outdoor heat exchanger, the indoor unit of the air conditioner includes an indoor heat exchanger, and an expansion valve may be provided in the indoor unit or the outdoor unit.

The indoor heat exchanger and the outdoor heat exchanger function as a condenser or an evaporator. When the indoor heat exchanger is used as a condenser, the air conditioner is used as a heater of a heating mode, and when the indoor heat exchanger is used as an evaporator, the air conditioner is used as a cooler of a cooling mode.

An air conditioner according to some embodiments of the present application includes an air conditioner indoor unit installed in an indoor space. The indoor unit of the air conditioner is connected to the outdoor unit of the air conditioner installed in the outdoor space through a pipe. The air conditioner outdoor unit may be provided with a compressor, an outdoor heat exchanger, an outdoor fan, an expander and the like for system circulation, and the air conditioner indoor unit may be provided with an indoor heat exchanger and an indoor fan.

An air conditioner according to an embodiment of the present invention is described below with reference to fig. 2 and 3.

As shown in fig. 2, a block diagram of an air conditioner according to an embodiment of the present invention, in which an air conditioner 10 includes a compressor 1, an outdoor heat exchanger 2, a temperature sensor 3, and a controller 4. Wherein a temperature sensor 3 is provided on the outdoor heat exchanger 2 for detecting an outdoor coil temperature.

The controller 4 is connected with the compressor 1 and the temperature sensor 3, the controller 4 may be a Processor with data processing and analysis functions, such as a CPU (Central Processing Unit/Processor, central processing unit) in an air conditioner, and the controller 4 may include a monitoring unit, a judging unit, a control unit, and the like, for implementing data processing and analysis.

The controller 4 is configured to acquire an operating frequency of the compressor 1 when the air conditioner 10 is operated for heating.

In some embodiments of the present invention, the controller 4 is further configured to determine that the air conditioner 10 is heating operation when detecting that the air conditioner 10 starts to operate in the heating mode and the continuous operation time reaches the first preset time period, wherein 10min is less than or equal to the first preset time period.

For a general air conditioner 10, after the compressor 1 is started to operate for 10min, the operating frequency is gradually stable, the system tends to be in a stable state, the starting time of the compressor 1 and the continuous operation time period are set to be equal to or longer than 10min, the first preset time period can be set to be equal to or longer than 10min, if the heating operation state of the air conditioner 10 is detected when the heating operation state of the air conditioner is smaller than 10min, the operating frequency of the compressor 1 is not stable, and the acquired data is not stable at the moment and possibly influences the judgment result.

In an embodiment, the system is brought to a steady state after the air conditioner 10 is turned on for a period of time, at which time the compressor 1 is operated at a steady frequency. When the air conditioner 10 is operated in the heating mode, the operating frequency F of the compressor 1 may be increased when the indoor environment temperature is reduced or the user controls the air conditioner to change from the mute mode to the low-wind mode or the user controls the air conditioner 10 to change from the sleep mode or the mute mode to the normal heating mode during the actual use of the air conditioner 10 by the user.

In some embodiments of the present invention, it is determined that the increased value of the operating frequency within the preset period exceeds the preset frequency threshold, and the air conditioner 10 is controlled to enter the pseudo defrost mode.

It will be appreciated that a change in the operating frequency F of the compressor 1 will cause the air conditioning system to fluctuate, while an insufficient supply of refrigerant in a short period of time will cause the vapor side pressure to drop, which in turn will cause the outdoor coil temperature to drop suddenly.

In particular, it will be described with reference to FIG. 3, as shown in FIG. 3, which is a schematic diagram of an outdoor coil temperature affected by an operating frequency of a compressor according to one embodiment of the present invention, wherein the outdoor coil temperature is denoted as T _{Outer disc} The line M in the figure shows the variation of the operating frequency F of the compressor 1 over time; line N in the figure indicates that the outdoor coil temperature is recorded as T _{Outer disc} A change over time; line Q in the figure shows the outdoor coil temperature recorded as T _{Outer disc} Time-dependent changes.

For example, as indicated by line N, starting at time T0, the operating frequency F of the compressor 1 suddenly increases, the outdoor coil temperature T _{Outer disc} Start to fall and at time T1 to the minimum, if at this time the outdoor coil temperature T _{Outer disc} Has been reduced to meet the conditions for entering the conventional defrost mode. But at this time the outdoor coil temperature T _{Outer disc} The drop is caused by the unstable operation of the compressor 1, and in fact the outdoor heat exchanger 2 may be frostless or have a very small amount of frost, which may result in a slight drop in indoor ambient temperature if the air conditioner 10 is still operated in the conventional defrost mode. However, the user controls the air conditioner 10 to increase the air output or change from the sleep mode or the mute mode to the conventional heating mode, so that the indoor environment temperature is required to be increased, the air conditioner 10 enters the conventional defrosting mode and the user will be violated, the user comfort experience is reduced, and if the air conditioner 10 frequently has the phenomenon of frostless defrosting, the user experience is poor, and even user complaints can be caused.

And, as shown by line N, the outdoor coil temperature T after time T3 _{Outer disc} Will rise back to a steady state, if the temperature after the rise does not meet the condition of the air conditioner 10 entering the normal defrost mode, the air conditioner will now10 need to exit the defrost mode again to continue operating the heating mode. In this process, the air conditioner 10 briefly operates in the normal defrosting mode, not only does not achieve the corresponding defrosting effect, but also consumes additional energy.

Based on the above, the embodiment of the present invention proposes a new defrosting control mode, and introduces a control parameter of a preset frequency threshold, where the preset frequency threshold is denoted by a, it can be understood that, during normal operation of the air conditioner 10, the operating frequency F of the compressor 1 may slightly fluctuate due to various reasons, and if the preset frequency threshold a is set to a smaller value, the air conditioner 10 frequently enters the false defrosting mode, which may result in waste of control resources. Specifically, different preset frequency thresholds a can be set according to the configuration of the air conditioning system and according to the characteristics and the configuration of the system. For example, a preset frequency threshold A is more than or equal to 3Hz, and if A can take the value of 3Hz or 4Hz or 6Hz or 8Hz or 10Hz, etc.

In the heating mode of operation of the air conditioner 10, the operation frequency F of the compressor is acquired once at regular intervals. Specifically, a preset period, which is a time period for detecting the operating frequency F of the compressor 1, may be set as needed, and denoted by t. Because the duration of the abrupt change of the operating frequency F of the compressor 1 is relatively short and the time of the system in the unsteady state is relatively short, the preset period t of the operating frequency F of the compressor 1 needs to be set and detected, so that the change condition of the operating frequency F of the compressor 1 cannot be detected in time. Different preset periods t can be set according to the configuration of the air conditioning system and the characteristics and the configuration of the system, wherein t is more than or equal to 1s and less than or equal to 1min can be set, and for example, the preset periods can be 1s or 10s or 20s or 30s or 50s or 1min and the like. It will be appreciated that setting the preset period t to a small value allows the detection of a change in the operating frequency F of the compressor in a short time.

Further, when an abrupt increase in the operating frequency fj of the compressor 1 is detected, an increase in the operating frequency fj of the compressor 1 needs to be calculated. Specifically, the last detected operating frequency of the compressor 1 may be denoted as F (n-1), the currently detected operating frequency of the compressor 1 may be denoted as F (n), and n is equal to or greater than 1, so that the increasing value Δf=f (n) -F (n-1) of the operating frequency of the compressor 1 may be calculated. If it is detected that the increased value Δf of the operating frequency of the compressor 1 satisfies Δf > a within the preset period t, it is determined that the operating frequency F of the compressor 1 is rapidly increased in a short time, and in order to prevent the air conditioner 10 from erroneously entering the normal defrosting mode, at this time, the air conditioner 10 may be controlled to enter the pseudo defrosting mode first, and then it is further determined whether it is necessary to control the air conditioner 10 to operate the normal defrosting mode.

In other embodiments, the outdoor coil temperature T is obtained in a pseudo-defrost mode _{Outer disc} The outdoor coil temperature at the (n+1) th time is determined to be less than the outdoor coil temperature at the n-th time, the air conditioner 10 is controlled to maintain the heating operation so as not to perform the outdoor defrosting, and the condition for entering the normal defrosting mode is defined that the outdoor ambient temperature is not satisfied, where n is a natural number.

Wherein, the outdoor coil temperature at the (n+1) th time is recorded as T _{Outer disc} (n+1) and the outdoor coil temperature at the nth time is denoted as T _{Outer disc} (n)。

Specifically, when the operating frequency F of the compressor 1 suddenly increases, the air conditioning system inevitably fluctuates, and the parameters characterizing the fluctuation of the air conditioning system are the indoor coil temperature, the outdoor coil temperature T _{Outer disc} The discharge temperature, the operating frequency F of the compressor 1, the indoor wind speed, etc. The degree of influence of the operating frequency F of the compressor 1 upon the abrupt change of the above-described parameters can be described in conjunction with table 1. Wherein, "+_number represents a strong correlation degree, i.e., the more" +_number affects the greater.

TABLE 1

	Indoor coil temperature	Outdoor coil temperature	Exhaust temperature
				Indoor wind speed	★★★★	★	★★★
Operating frequency of compressor	★★★★	★★★★★	★★★★★

As can be seen from table 1, the abrupt change in the operating frequency F of the compressor 1 versus the outdoor coil temperature T _{Outer disc} Is very influential and is therefore based on the outdoor coil temperature T _{Outer disc} And the running frequency F of the compressor 1 controls the conditions of frostless defrosting and frequent defrosting of the air conditioner possibly occurring under unsteady state, so that the user experience can be improved, and the consumption of energy sources is prevented.

As can be seen from table 1, when the operating frequency F of the compressor 1 suddenly changes, the outdoor coil temperature T is inevitably caused _{Outer disc} When the temperature T of the outdoor coil is changed, i.e. the air conditioner 10 just begins to enter the pseudo-defrosting mode, the temperature T of the outdoor coil is inevitably generated _{Outer disc} A reduced situation. That is to say, the outdoor coil temperature T is initially checked _{Outer disc} In the case of a change in (1), T must be satisfied _{Outer disc} (n+1)＜T _{Outer disc} (n). However, when the operating frequency F of the compressor 1 increases, the outdoor heat exchanger 2 may be in a short time with insufficient refrigerant supply, resulting in a rapid decrease in the evaporating pressure, i.e., the outdoor coil temperature T _{Outer disc} Rapidly decreasing, if the outdoor frosting condition is judged only by the outdoor heat exchange temperature difference, the compressor 1 is operatedThe sudden rise of the line frequency F and the subsequent time period, the large outdoor heat exchange temperature difference does not reflect the actual frosting of the outdoor heat exchanger 2, and thus the controller 4 cannot accurately determine whether it has actually reached the defrosting condition. Wherein the outdoor heat exchange temperature difference deltatout=the outdoor ambient temperature Tout-the outdoor coil temperature T _{Outer disc} If at this time, the outdoor coil temperature T _{Outer disc} Lowering the condition as a control to the air conditioner 10 to enter the normal defrosting mode may cause a misjudgment, and the air conditioner 10 is liable to enter the normal defrosting mode by mistake. Referring to the line in fig. 3, in the pseudo defrost mode, even if T is detected _{Outer disc} (n+1)＜T _{Outer disc} (n) determining the outdoor coil temperature T _{Outer disc} Drop, also need not to judge the temperature T of the outdoor coil _{Outer disc} Whether the condition of entering the normal defrosting mode is met or not, at this time, the air conditioner 10 is controlled not to enter the normal defrosting mode and keeps continuously the current heating operation, so that the condition that the indoor environment temperature is reduced and the user experience is influenced due to the fact that the air conditioner enters the normal defrosting mode by mistake is avoided.

It will be appreciated that the specific decision process for the conventional defrost mode is as follows: after the compressor is continuously operated for a period of time, the outdoor environment temperature Tout and the outdoor coil temperature T are collected _{Outer disc} And determining a first temperature threshold value, T, for Tout _{Outer disc} When the temperature is less than or equal to the second temperature threshold and the temperature delta Tout is less than or equal to the third temperature threshold, entering a conventional defrosting mode, and in the conventional defrosting mode, when T is detected _{Outer disc} And when the temperature threshold value of the conventional defrosting mode is not smaller than the preset temperature threshold value, the conventional defrosting mode is not larger than the preset temperature threshold value. The first temperature threshold, the second temperature threshold, the third temperature threshold, and the temperature threshold for exiting the normal defrosting mode may be set as needed, which is not limited herein.

Based on the above, since the outdoor heat exchange temperature difference Δtout cannot represent the frosting condition in the pseudo-defrosting mode, the air conditioner 10 can be controlled to start entering the pseudo-defrosting mode without collecting the outdoor ambient temperature Tout, or can directly assign a fixed value to the outdoor ambient temperature Tout and set the fixed value to be greater than the second temperature threshold, so that in the pseudo-defrosting mode, the condition that the outdoor ambient temperature does not meet the condition of entering the conventional defrosting mode is always limited, thereby preventing the air conditioner from entering the conventional defrosting mode by mistake.

Further, in an embodiment, it may be determined that the outdoor coil temperature T at the (n+1) th time is satisfied by the continuous preset number of times of the outdoor coil temperature _{Outer disc} (n+1) is less than the outdoor coil temperature T at time n _{Outer disc} The condition of (n) in which there is a possibility that there is a false detection with a small number of times, for example, the number of times may be set to be 2 or more, for example, the number of times may be set to be 2 or 3 or 4, or the like, that is, by the temperature T of the outdoor coil _{Outer disc} Repeated detection and judgment are carried out, and the accuracy of the detection result and the judgment result can be ensured.

In other embodiments of the present invention, the outdoor coil temperature T at time (m+1) is further determined a first predetermined number of times _{Outer disc} (m+1) is not lower than the outdoor coil temperature T at the mth time _{Outer disc} (m) controlling the air conditioner 10 to continue the heating operation, wherein n is a natural number.

Wherein, different first preset times can be set according to the configuration of the air conditioning system and the characteristics and the configuration of the system, wherein the first preset times can be set to be more than or equal to 2 times, for example, the first preset times can be 2 times or 3 times or 4 times or 5 times or 6 times, etc., through the temperature T of the outdoor coil pipe _{Outer disc} Repeated detection and judgment are carried out, and the accuracy of the detection result and the judgment result can be ensured.

Wherein the outdoor coil temperature T at time (n+1) is determined _{Outer disc} (n+1) is less than the outdoor coil temperature T at time n _{Outer disc} (n) after that, repeatedly detecting the outdoor coil temperature T _{Outer disc} . Taking the first preset number of times as 2 times as an example, when the outdoor coil temperature T at the (m+1) th moment is detected for more than 2 times continuously _{Outer disc} (m+1) is not lower than the outdoor coil temperature T at the mth time _{Outer disc} (m), i.e. T _{Outer disc} (m+1)≥T _{Outer disc} (m) then represents the outer coil temperature T _{Outer disc} Inflection point appears, outdoor coil temperature T _{Outer disc} And starts to rise or is about to be stable, and at the moment, the air conditioner 10 is still in an unstable state, and the heating operation is controlled to be continuously kept.

Specifically, as shown by line N in FIG. 3, at t1-In the T3 period, the outdoor coil temperature T _{Outer disc} At a gradual rise, the outdoor coil temperature T detected during this process _{Outer disc} Will satisfy T _{Outer disc} (m+1)＞T _{Outer disc} (m) if the outdoor coil temperature T is detected at this time _{Outer disc} The outdoor coil temperature T has been restored to the temperature at which the air conditioner 10 normally operates in the heating mode _{Outer disc} However, in practice, the system is still in an unstable state, and the air conditioner 10 cannot be controlled to immediately exit the pseudo-defrosting mode, so that the air conditioner 10 should be controlled to continue to keep the heating operation. And, if at this time, the outdoor coil temperature T is detected _{Outer disc} Although it has risen, the outdoor coil temperature T at this time _{Outer disc} The condition for entering the normal defrosting mode is still lower or even satisfied, but because the system is still in an unstable state, if the air conditioner 10 is controlled to immediately exit the false defrosting mode at this time, the air conditioner 10 directly enters the normal defrosting mode after exiting the false defrosting mode, and in fact, the outdoor heat exchanger 2 may not be frosted or the frost amount is very small, if the air conditioner 10 still operates in the normal defrosting mode at this time, the indoor environment temperature may be slightly reduced, so that the air conditioner 10 should be controlled to continue to keep the heating operation and not enter the normal defrosting mode at this time, and the outdoor environment temperature should be continuously limited to not satisfy the condition for entering the normal defrosting mode at this time, so as to prevent the air conditioner from entering the normal defrosting mode by mistake.

According to the air conditioner 10 of the embodiment of the invention, a false defrosting mode is provided, and the air conditioner is controlled to enter the false defrosting mode by detecting the operating frequency F of the compressor 1 and determining that the added value delta F of the operating frequency F of the compressor 1 in a preset period exceeds a preset frequency threshold A. The temperature sensor 3 is used for acquiring the temperature T of the outdoor coil _{Outer disc} In turn, may provide a data reference for the current operating strategy of the air conditioner 10. For the outdoor coil temperature T caused by the variation of the operating frequency F of the compressor 1 _{Outer disc} Under the changed unsteady state, the phenomena of defrosting without frost and frequent defrosting can be effectively avoided, and the control is more accurate. And determining the outdoor coil temperature T in a system unsteady state _{Outer disc} When the air conditioner starts to rise or tends to be stable, the air conditioner 10 is controlled to keep heating operation and defrost falseThe control of the exit condition of the mode is more accurate, and the user experience is improved.

In some embodiments of the present invention, in the pseudo defrost mode, the controller 4 is further configured to: recording the outdoor coil temperature T at the (m+1) th moment determined continuously a first preset number of times _{Outer disc} (m+1) is not lower than the outdoor coil temperature T at the mth time _{Outer disc} The operating frequency F of the compressor 1 at the time of (m) is the first frequency.

From the above examples, it is understood that the outdoor coil temperature T at the (n+1) th time is determined _{Outer disc} (n+1) is less than the outdoor coil temperature T at time n _{Outer disc} After (n), when T is detected continuously for a first preset number of times _{Outer disc} (m+1)≥T _{Outer disc} (m) at this time, the system may still be in an unstable state, and at this time, the operating frequency F of the compressor 1 may not reach the stable operating state, and the operating frequency F of the compressor 1 at this time is recorded as a first frequency, which is generally greater than or equal to the operating frequency F of the compressor 1 when the air conditioner 10 is operating in the heating mode normally, and meanwhile, the air conditioner 10 should be controlled to continue to maintain the heating operation, not enter the normal defrosting mode, and perform the repetitive detection and determination.

Further, in other embodiments, the outdoor coil temperature T at time (m+1) is determined from a continuous first preset number of times _{Outer disc} (m+1) is not lower than the outdoor coil temperature T at the mth time _{Outer disc} Starting at the instant of (m), further determining the outdoor coil temperature T _{Outer disc} The outdoor coil temperature T remains unchanged or is determined at time (i+1) _{Outer disc} (i+1) an outdoor coil temperature T less than the i-th time _{Outer disc} (i) And the operating frequency F of the compressor 1 is not greater than the first frequency, where i > m.

Wherein, in some embodiments, at the time of determining (i+1) th outdoor coil temperature T _{Outer disc} (i+1) an outdoor coil temperature T less than the i-th time _{Outer disc} (i) Determining the outdoor coil temperature T continuously for a second preset number of times _{Outer disc} Satisfies the outdoor coil temperature T at the (i+1) th time _{Outer disc} (i+1) an outdoor coil temperature T less than the i-th time _{Outer disc} (i)。

Specifically, different first preset times can be set according to the configuration of the air conditioning system and according to the characteristics and the configuration of the system, wherein the second preset times can be set to be more than or equal to 2 times, for example, the second preset times can be 2 times or 3 times or 4 times or 5 times or 6 times, and the like, through the temperature T of the outdoor coil pipe _{Outer disc} Repeated detection and judgment are carried out, and the accuracy of the detection result and the judgment result can be ensured.

Specifically, as indicated by line N in FIG. 3, during the time period T1-T3, the outdoor coil temperature T _{Outer disc} At a gradual rise, the outdoor coil temperature T detected during this process _{Outer disc} Will satisfy T _{Outer disc} (m+1)≥T _{Outer disc} (m) at the time (m+1) th detected outdoor coil temperature T _{Outer disc} (m+1) is not lower than the outdoor coil temperature T at the mth time _{Outer disc} (m) after that, a further detection of the outdoor coil temperature T is also required _{Outer disc} . For example, after time T3, the outdoor coil temperature T is detected _{Outer disc} If the operating frequency F of the compressor 1 is not greater than the first frequency, that is, the operating frequency F of the compressor 1 is less than or equal to the first frequency, it is determined that the operating frequency F of the compressor 1 also substantially reaches the steady state, and it is confirmed that the system has been restored to the steady state at this time.

More specifically, as indicated by line Q in FIG. 3, during the period T1-T2, the outdoor coil temperature T _{Outer disc} Is also gradually raised, in the course of which the outdoor coil temperature T is detected _{Outer disc} Will also satisfy T _{Outer disc} (m+1)≥T _{Outer disc} (m) at the time (m+1) th detected outdoor coil temperature T _{Outer disc} (m+1) is not lower than the outdoor coil temperature T at the mth time _{Outer disc} (m) after time T2, the outdoor coil temperature T is further detected _{Outer disc} Starting to drop, e.g. determining the outdoor coil temperature T at time (i+1) _{Outer disc} (i+1) an outdoor coil temperature T less than the i-th time _{Outer disc} (i) Since the outdoor coil temperature T caused by unsteady state of the system has been experienced at this time _{Outer disc} Discrimination of the occurrence of fluctuations, when the outdoor coil temperature T is detected again _{Outer disc} Decline and detectIf the operating frequency F of the compressor 1 is not greater than the first frequency, i.e., if no abrupt change occurs in the operating frequency F of the compressor 1, the outdoor coil temperature T is determined _{Outer disc} The descent may be caused by the occurrence of a frost layer of the outdoor unit.

Based on the above, when it is confirmed that the system has been restored to the stable state, or the system has been restored to the stable state and the outdoor unit may have a frost layer, the air conditioner 10 is controlled to exit the pseudo-defrosting mode, continue the heating operation, and cancel the limitation of the outdoor environment temperature.

After the air conditioner 10 exits the pseudo defrost mode, it is necessary to normally perform a condition determination of the normal defrost mode, and thus it is necessary to normally detect the outdoor ambient temperature Tout. Based on this, the air conditioner 10 may be set to normally collect the outdoor ambient temperature Tout or cancel the assignment of the outdoor ambient temperature Tout while the air conditioner 10 exits the pseudo-defrost mode, to ensure that the air conditioner 10 can enter the normal defrost mode to perform the defrost operation.

According to the air conditioner 10 of the embodiment of the present invention, the outdoor coil temperature T is detected _{Outer disc} And the running frequency F of the compressor 1, after the fluctuation of the air conditioning system is determined and tends to be stable, the air conditioner 10 is timely controlled to exit the false defrosting mode to run the conventional heating mode, so that the extra energy consumption is avoided, the experience of a user is ensured, and the requirement of the user on the comfort degree under the heating working condition is met.

In some embodiments of the present invention, in the pseudo defrost mode, the controller 4 is further configured to: outdoor coil temperature T at time (n+1) of determination _{Outer disc} (n+1) is less than the outdoor coil temperature T at time n _{Outer disc} (n) after further determining the outdoor coil temperature T _{Outer disc} And rise again to an outdoor coil temperature T _{Outer disc} Is kept unchanged after rising to the first temperature, and the outdoor coil temperature T _{Outer disc} The period of time for which the first temperature is kept unchanged is reduced to a second temperature after reaching the first period of time, and the operating frequency F of the compressor 1 is increased to a second frequency unchanged, the air conditioner 10 is controlled to defrost outdoors, and the limitation of the outdoor ambient temperature is canceled, wherein the second temperature reaches the defrosting temperature.

In a system unsteady stateTemperature T of outdoor coil _{Outer disc} A decrease and then a rebound situation may occur. For example, as shown by line Q in fig. 3, starting at time T0, the operating frequency F of the compressor 1 suddenly increases, the outdoor coil temperature T _{Outer disc} Start to fall and at time T1 to the minimum, after time T1, the outdoor coil temperature T _{Outer disc} Gradually rise back and after time T2 the outdoor coil temperature T _{Outer disc} Will rise back to the second temperature and remain unchanged for a short period of time. The values of the second temperature and the first duration may be set as required, and are not limited herein.

Further, as shown by a line Q in fig. 3, if the operating frequency F of the compressor 1 is not changed and the air conditioning system is stable after a certain time, the outdoor coil temperature T is generated _{Outer disc} When the condition for entering the normal defrosting mode is lowered and satisfied, for example, the outdoor coil temperature T shown at time T3 _{Outer disc} When the temperature has fallen to the second temperature and the defrosting temperature has been reached, i.e., the condition for entering the normal defrosting mode is satisfied, it indicates that the outdoor coil is frosted at this time, and defrosting of the outdoor unit is required, and at this time, the air conditioner 10 can normally perform the defrosting operation. While the air conditioner 10 is exiting the normal heating mode of the pseudo-defrost mode, the air conditioner 10 may be set to normally collect the outdoor ambient temperature Tout or cancel the assignment of the outdoor ambient temperature Tout to ensure that the air conditioner 10 can enter the normal defrost mode to perform the defrost operation.

Therefore, according to the air conditioner 10 of the embodiment of the present invention, only the outdoor coil temperature T caused by the variation of the operation frequency F of the compressor 1 is aimed at _{Outer disc} The phenomena of frostless and defrosting, frequent defrosting and the like which occur under the changed unsteady state can not influence the defrosting operation of the air conditioner 10 when the outdoor coil is really in defrosting demand, and the air conditioner is more intelligent and can not influence the user experience.

A defrosting control method of an air conditioner according to an embodiment of the present invention will be described with reference to fig. 4 to 8. It should be noted that, the step numbers S1, S2, S3, S4, etc. in the present application are only for convenience of describing the present embodiment, and are not to be construed as limiting the order of the steps. That is, for example, the execution order of steps S1, S2, S3, S4, etc. may be specifically determined according to actual demands, and is not limited to control in the order of steps in the following embodiments.

In some embodiments of the present invention, as shown in fig. 4, a flowchart of a defrosting control method for an air conditioner according to an embodiment of the present invention is shown, wherein the defrosting control method for an air conditioner at least includes steps S1 to S4, which are specifically described below.

S1, detecting heating operation of the air conditioner and obtaining the operation frequency of the compressor.

In some embodiments of the present invention, it is detected that the air conditioner starts to operate the heating mode and the continuous operation time reaches a first preset duration, where 10min is less than or equal to the first preset duration.

For a general air conditioner, the compressor can tend to a stable state after being started to run for 10min, the first preset duration can be set to be less than or equal to 10min, and if the heating running state of the air conditioner is detected when the heating running state of the air conditioner is less than 10min, the running frequency of the compressor is unstable, and the judging result can be influenced by the unstable data acquired at the moment. Wherein the operating frequency of the compressor may be denoted by F.

In the embodiment, when the air conditioner is operated in the heating mode, in the process that the user actually uses the air conditioner, when the indoor environment temperature is reduced or the user controls the air conditioner to change from the mute mode and the low wind mode to the high wind mode, or when the user controls the air conditioner to change from the sleep mode or the mute mode to the conventional heating mode, the situation that the operation frequency F of the compressor is increased occurs.

S2, determining that the increased value of the running frequency in the preset period exceeds a preset frequency threshold value, and controlling the air conditioner to enter a false defrosting mode.

In particular, it can be described in connection with FIG. 3, wherein the outdoor coil temperature is noted as T _{Outer disc} As shown in fig. 3, a line M represents a time-dependent change in the operating frequency F of the compressorThe chemical condition; line N indicates the outdoor coil temperature is recorded as T _{Outer disc} A change over time; line Q indicates that the outdoor coil temperature is recorded as T _{Outer disc} Time-dependent changes.

For example, as indicated by line N, starting at time T0, the compressor operating frequency F suddenly increases, the outdoor coil temperature T _{Outer disc} Start to fall and at time T1 to the minimum, if at this time the outdoor coil temperature T _{Outer disc} Has been reduced to meet the conditions for entering the conventional defrost mode. But at this time the outdoor coil temperature T _{Outer disc} The drop is caused by unstable operation of the compressor, and in practice the outdoor heat exchanger may be frostless or have a very small amount of frost, which may result in a slight drop in indoor ambient temperature if the air conditioner is still operated in the conventional defrost mode. However, at this time, the air conditioner enters a conventional defrosting mode and the user wants to raise the indoor environment temperature, so that the user comfort experience is reduced, and if the air conditioner frequently has frostless defrosting, the user experience is poor, and even user complaints are caused.

And, as shown by line N, the outdoor coil temperature T after time T3 _{Outer disc} And the temperature can rise back to a stable state, and if the temperature after rising back does not meet the condition that the air conditioner enters the conventional defrosting mode, the air conditioner needs to exit the defrosting mode again at the moment to continue to operate the heating mode. In this process, the air conditioner briefly operates in the conventional defrosting mode, which cannot achieve the corresponding defrosting effect, and consumes additional energy.

Based on the above situation, the embodiment of the invention provides a new defrosting control mode, and introduces a control parameter of a preset frequency threshold, wherein the preset frequency threshold is denoted by a, and different preset frequency thresholds a can be set according to the configuration of the air conditioning system and the characteristics and configuration of the system. For example, a preset frequency threshold A is more than or equal to 3Hz, and if A can take the value of 3Hz or 4Hz or 6Hz or 8Hz or 10Hz, etc.

It can be understood that, during normal operation of the air conditioner, the operation frequency F of the compressor may slightly fluctuate due to various reasons, and if the preset frequency threshold value a is set to a smaller value, the air conditioner frequently enters the false defrosting mode, which may cause waste of control resources. Specifically, the operation frequency F of the compressor is obtained once at regular intervals when the air conditioner is operated in the heating mode. Specifically, a preset period, which is a period of time for detecting the operating frequency F of the compressor as required, may be set, and the preset period is denoted by t. Because the duration of the abrupt change of the operating frequency F of the compressor is relatively short and the time of the system in an unsteady state is relatively short, the preset period t of the operating frequency F of the compressor needs to be set and detected, so that the condition that the change of the operating frequency F of the compressor cannot be detected in time is avoided. Different preset periods t can be set according to the configuration of the air conditioning system and the characteristics and the configuration of the system, wherein t is more than or equal to 1s and less than or equal to 1min can be set, and for example, the preset periods can be 1s or 10s or 20s or 30s or 50s or 1min and the like. It will be appreciated that setting the preset period t to a small value allows detection of a change in the operating frequency F of the compressor in a short time.

Further, when an abrupt increase in the operating frequency fj of the compressor is detected, an operating frequency fj of the compressor needs to be calculated. The frequency increment, i.e. the increment value of the operating frequency of the compressor, is denoted as Δf, specifically, the last detected operating frequency of the compressor may be denoted as F (n-1), the current detected operating frequency of the compressor may be denoted as F (n), and n is greater than or equal to 1, where Δf=f (n) -F (n-1) may be calculated. If the increased value DeltaF of the operating frequency of the compressor meets DeltaF & gtA within the preset period t is detected, the operating frequency F of the compressor is determined to be rapidly increased in a short time, and in order to prevent the air conditioner from entering the conventional defrosting mode by mistake, the air conditioner can be controlled to enter the pseudo-defrosting mode at this time, and then whether the air conditioner needs to be controlled to operate the conventional defrosting mode is further determined.

S3, acquiring the temperature of the outdoor coil from the moment of entering the pseudo-defrosting mode, determining that the temperature of the outdoor coil at the (n+1) th moment is smaller than the temperature of the outdoor coil at the nth moment, and controlling the air conditioner to keep heating operation so as not to defrost outdoors, wherein the condition that the temperature of the outdoor environment does not meet the condition of entering the normal defrosting mode is limited, and n is a natural number.

Wherein, the outdoor coil temperature at the (n+1) th time is recorded as T _{Outer disc} (n+1) the outdoor coil temperature at the nth time is referred to as T _{Outer disc} (n)。

Specifically, when the operating frequency F of the compressor suddenly increases, the air conditioning system inevitably fluctuates, and parameters characterizing the fluctuation of the air conditioning system are the indoor coil temperature and the outdoor coil temperature T _{Outer disc} The exhaust temperature, the operating frequency F of the compressor, the indoor wind speed, etc. The degree of influence of the operating frequency F of the compressor upon a sudden change in the above parameters can be described in conjunction with table 1.

As can be seen from table 1 above, when the operating frequency F of the compressor suddenly changes, the outdoor coil temperature T is inevitably caused _{Outer disc} When the temperature T of the outdoor coil is changed, namely the air conditioner starts to enter the false defrosting mode, the temperature T of the outdoor coil is also necessarily generated _{Outer disc} A reduced situation. That is to say, at the beginning, checking the outdoor coil temperature T _{Outer disc} In the case of a change in (1), T must be satisfied _{Outer disc} (n+1)＜T _{Outer disc} (n). However, when the operating frequency F of the compressor increases, the refrigerant supply of the outdoor heat exchanger is insufficient in a short time, resulting in a rapid decrease in the evaporating pressure, i.e., the outdoor coil temperature T _{Outer disc} If the outdoor frosting condition is judged only by the outdoor heat exchange temperature difference, the outdoor heat exchange temperature difference is large and cannot reflect the real frosting condition of the outdoor heat exchanger in the period of sudden rise of the operation frequency F of the compressor and the subsequent period of time, wherein the outdoor heat exchange temperature difference delta tout=the outdoor environment temperature Tout-the outdoor coil temperature T _{Outer disc} The controller cannot accurately determine whether it has actually reached the defrost condition. If at this time at the outdoor coil temperature T _{Outer disc} Lowering the condition for controlling the air conditioner to enter the normal defrosting mode may result in misjudgment, and the air conditioner is still prone to enter the normal defrosting mode by mistake. Referring to the line in fig. 3, in the pseudo defrost mode, even if T is detected _{Outer disc} (n+1)＜T _{Outer disc} (n) determining the outdoor coil temperature T _{Outer disc} Drop, also need not to judge the temperature T of the outdoor coil _{Outer disc} Whether the condition of entering the conventional defrosting mode is met or not, at the moment, the air conditioner is controlled not to enter the conventional defrosting mode and keeps continuously the current heating operation, and the condition that the indoor environment temperature is reduced to influence the user experience caused by the fact that the air conditioner enters the conventional defrosting mode by mistake is avoided.

It will be appreciated that the specific determination of the normal defrost mode is to collect the outdoor ambient temperature Tout and the outdoor coil temperature T after a period of continuous compressor operation _{Outer disc} And determining a first temperature threshold value, T, for Tout _{Outer disc} And when the temperature is less than or equal to the second temperature threshold and the temperature delta Tout is less than or equal to the third temperature threshold, entering a conventional defrosting mode, wherein the temperature thresholds of the first temperature threshold, the second temperature threshold, the third temperature threshold and exiting the conventional defrosting mode can be set according to the needs, and the temperature thresholds are not limited herein. The outdoor heat exchange temperature difference delta Tout can not represent frosting condition in the pseudo defrosting mode, so that the air conditioner can be controlled to not collect the outdoor environment temperature Tout at the beginning of entering the pseudo defrosting mode, or can be directly assigned to the outdoor environment temperature Tout to be a fixed value, and the fixed value is set to be more than a second temperature threshold value, and further, in the pseudo defrosting mode, the condition that the outdoor environment temperature does not meet the condition of entering the conventional defrosting mode is always limited, so that the conventional defrosting mode is prevented from being wrongly entered.

Further, in an embodiment, it may be determined that the outdoor coil temperature T at the (n+1) th time is satisfied by the continuous preset number of times of the outdoor coil temperature _{Outer disc} (n+1) is less than the outdoor coil temperature T at time n _{Outer disc} The condition of (n) in which there is a possibility that there is a false detection with a small number of times, for example, the number of times may be set to be 2 or more, for example, the number of times may be set to be 2 or 3 or 4, or the like, that is, by the temperature T of the outdoor coil _{Outer disc} Repeated detection and determination can be performedAnd the accuracy of the detection result and the judgment result is ensured.

S4, further continuously determining that the temperature of the outdoor coil meets the requirement that the temperature of the outdoor coil at the (m+1) th moment is not lower than the temperature of the outdoor coil at the m th moment for a first preset time, and controlling the air conditioner to continuously keep heating operation, wherein m is a natural number, and the first preset time is more than or equal to 2 times.

Wherein the outdoor coil temperature T at time (n+1) is determined _{Outer disc} (n+1) is less than the outdoor coil temperature T at time n _{Outer disc} (n) after that, repeatedly detecting the outdoor coil temperature T _{Outer disc} . Taking the first preset number of times as 2 times as an example, when more than 2 times continuously detect T _{Outer disc} (m+1)≥T _{Outer disc} (m) then represents the outer coil temperature T _{Outer disc} Inflection point appears, outdoor coil temperature T _{Outer disc} The air conditioner 10 should be controlled to continue to maintain the heating operation while the outdoor ambient temperature should be continuously limited not to satisfy the condition of entering the conventional defrost mode in order to prevent erroneous entry into the conventional defrost mode, starting to rise or coming to a steady state.

Specifically, as indicated by line N in FIG. 3, during the time period T1-T3, the outdoor coil temperature T _{Outer disc} At a gradual rise, the outdoor coil temperature T detected during this process _{Outer disc} Will satisfy T _{Outer disc} (m+1)≥T _{Outer disc} (m) if the outdoor coil temperature T is detected at this time _{Outer disc} Outdoor coil temperature T when air conditioner normal operation heating mode has been restored _{Outer disc} However, in practice, the system is still in an unstable state, and the air conditioner cannot be controlled to immediately exit the pseudo-defrosting mode, so that the air conditioner 10 should be controlled to continue to keep the heating operation. And, if at this time, the outdoor coil temperature T is detected _{Outer disc} Although it has risen, the outdoor coil temperature T at this time _{Outer disc} Still lower or even meeting the condition of entering the normal defrost mode, but because the system is still in an unstable state, if the air conditioner 10 is controlled to immediately exit the false defrost mode at this time, the normal defrost mode will be directly entered after the air conditioner 10 exits the false defrost mode, and in practice the outdoor heat exchanger may be frostless or have a very small amount of frost, which may result in a slight decrease in indoor environment temperature if the air conditioner is still operating in the normal defrost mode at this time. At this time, therefore, the air conditioner 10 should be controlled to continue the heating operation without entering the normal defrosting mode.

According to the defrosting control method of the air conditioner, a false defrosting mode is provided, and the air conditioner is controlled to enter the false defrosting mode by detecting the operating frequency F of the compressor and determining that the added value delta F of the operating frequency F of the compressor in a preset period exceeds a preset frequency threshold A. And by taking the outdoor coil temperature T _{Outer disc} And further, a data reference can be provided for the current operation strategy of the air conditioner. For the outdoor coil temperature T caused by the variation of the operating frequency F of the compressor _{Outer disc} Under the changed unsteady state, the phenomena of defrosting without frost and frequent defrosting can be effectively avoided, and the control is more accurate. And determining the outdoor coil temperature T in a system unsteady state _{Outer disc} When the air conditioner starts to rise or tends to be stable, the air conditioner is controlled to continue to keep heating operation, the control of the exit condition of the false defrosting mode is more accurate, and the user experience is improved.

In some embodiments of the present invention, as shown in fig. 5, which is a flowchart of a defrosting control method of an air conditioner according to another embodiment of the present invention, after further continuously determining that the outdoor coil temperature satisfies the outdoor coil temperature at the (m+1) th time not to be lower than the outdoor coil temperature at the m-th time a first preset number of times, the defrosting control method of an air conditioner further includes steps S41 to S43.

S41, recording the operation frequency of the compressor at the moment when the outdoor coil temperature at the (m+1) th moment is not lower than the outdoor coil temperature at the m th moment continuously and for a first preset number of times as a first frequency.

From the above examples, it is understood that the outdoor coil temperature T at the (n+1) th time is determined _{Outer disc} (n+1) is less than the outdoor coil temperature T at time n _{Outer disc} After (n), when T is detected continuously for a first preset number of times _{Outer disc} (m+1)≥T _{Outer disc} (m) when the system may still be in an unstable state and the operating frequency F of the compressor may not reach a stable operating state, recording the operating frequency F of the compressor at the next time as a first frequency F, where the first frequency is generally greater than or equal to the operating frequency of the compressor 1 when the air conditioner is in a normal operation heating mode, and meanwhile, the air conditioner should be controlled to continue to keep the heating operation, not enter a normal defrosting mode, and performing repeated detection and judgment.

S42, starting from a moment when the outdoor coil temperature at the (m+1) th moment is continuously and preset times to be not lower than the outdoor coil temperature at the m th moment, further determining that the outdoor coil temperature is unchanged or determining that the outdoor coil temperature at the (i+1) th moment is lower than the outdoor coil temperature at the i th moment and the operating frequency of the compressor is not greater than a first frequency, wherein i is greater than m.

Specifically, as indicated by line N in FIG. 3, during the time period T1-T3, the outdoor coil temperature T _{Outer disc} At a gradual rise, the outdoor coil temperature T detected during this process _{Outer disc} Will satisfy T _{Outer disc} (m+1)≥T _{Outer disc} (m) at the time (m+1) th detected outdoor coil temperature T _{Outer disc} (m+1) is not lower than the outdoor coil temperature T at the mth time _{Outer disc} (m) after that, a further detection of the outdoor coil temperature T is also required _{Outer disc} . For example, after time T3, the outdoor coil temperature T is detected _{Outer disc} And if the operating frequency F of the compressor is not greater than the first frequency, that is, the operating frequency F of the compressor is smaller than or equal to the first frequency, determining that the operating frequency F of the compressor also basically reaches the steady operation state, and confirming that the system is restored to the steady state at the moment.

More specifically, as indicated by line Q in FIG. 3, during the period T1-T2, the outdoor coil temperature T _{Outer disc} Is also gradually raised, in the course of which the outdoor coil temperature T is detected _{Outer disc} Will also satisfy T _{Outer disc} (m+1)≥T _{Outer disc} (m) at the time (m+1) th detected outdoor coil temperature T _{Outer disc} (m+1) is not lower than the outdoor coil temperature T at the mth time _{Outer disc} (m) after time T2, the outdoor coil temperature T is further detected _{Outer disc} Starting to drop, e.g. determining the outdoor coil temperature T at time (i+1) _{Outer disc} (i+1) an outdoor coil temperature T less than the i-th time _{Outer disc} (i) Since the outdoor coil temperature T caused by unsteady state of the system has been experienced at this time _{Outer disc} Discrimination of the occurrence of fluctuations, when the outdoor coil temperature T is detected again _{Outer disc} Falling and detecting that the operating frequency F of the compressor is not greater than the first frequency, i.e., that no abrupt change has occurred in the operating frequency F of the compressor, confirming the outdoor coil temperature T _{Outer disc} The descent may be caused by the occurrence of a frost layer of the outdoor unit.

S43, controlling the air conditioner to exit the false defrosting mode, continuing the heating operation, and canceling the limitation of the outdoor environment temperature.

Based on the above, when the system is confirmed to be restored to the stable state, or the system is confirmed to be restored to the stable state and the outdoor unit may have a frost layer, the air conditioner is controlled to exit the pseudo-defrosting mode, and the heating operation is continued. Further, after the air conditioner exits the pseudo defrosting mode, it is necessary to normally perform a condition determination of the normal defrosting mode, and thus it is necessary to normally detect the outdoor ambient temperature Tout. Based on this, the air conditioner may be set to normally collect the outdoor ambient temperature Tout while the air conditioner exits the pseudo-defrost mode, or cancel the assignment of the outdoor ambient temperature Tout, to ensure that the air conditioner can enter the normal defrost mode to perform the defrost operation.

According to the defrosting control method of the air conditioner, disclosed by the embodiment of the invention, the temperature T of the outdoor coil pipe is detected _{Outer disc} And the running frequency F of the compressor, after the fluctuation of the air conditioning system is determined and tends to be stable, the air conditioner is timely controlled to exit the false defrosting mode to run the conventional heating mode, so that the extra energy consumption is avoided, the experience of a user is ensured, and the requirement of the user on the comfort degree under the heating working condition is met.

In some embodiments of the present invention, as shown in fig. 6, a flowchart of a defrosting control method for an air conditioner according to still another embodiment of the present invention is shown, wherein the method further includes step S31.

S31, after the outdoor coil temperature at the (n+1) th moment is determined to be smaller than the outdoor coil temperature at the n th moment, further determining that the outdoor coil temperature rises again, keeping unchanged after the outdoor coil temperature rises to the first temperature, and reducing to the second temperature after the duration of keeping unchanged the outdoor coil temperature at the first temperature reaches the first time, and increasing the operating frequency of the compressor to the second frequency unchanged, controlling the air conditioner to defrost the outdoor, and canceling limitation on the outdoor environment temperature, wherein the second temperature reaches the defrosting temperature.

In the unsteady state of the system, the outdoor coil temperature T _{Outer disc} A decrease and then a rebound situation may occur. For example, as shown by line Q in fig. 3, starting at time T0, the operating frequency F of the compressor suddenly increases, the outdoor coil temperature T _{Outer disc} Start to fall and at time T1 to the minimum, after time T1, the outdoor coil temperature T _{Outer disc} Gradually rise back and after time T2 the outdoor coil temperature T _{Outer disc} Will rise back to the second temperature and remain unchanged for a short period of time. Wherein the second temperature is equal to the firstThe values of the time periods may be set as needed, and are not limited herein.

Further, as shown by the line Q in fig. 3, if the operating frequency F of the compressor is not changed and the air conditioning system is stable after a certain period of time, the outdoor coil temperature T is reached _{Outer disc} When the condition for entering the normal defrosting mode is lowered and satisfied, for example, the outdoor coil temperature T shown at time T3 _{Outer disc} When the temperature is reduced to the second temperature and the defrosting temperature is reached, namely the condition of entering the conventional defrosting mode is met, the outdoor coil is frosted at the moment, the outdoor unit needs to be defrosted, and the air conditioner can normally execute defrosting operation. When the air conditioner exits the normal heating mode in the pseudo-defrosting mode, the air conditioner can be set to normally collect the outdoor environment temperature Tout or cancel assignment of the outdoor environment temperature Tout so as to ensure that the air conditioner can enter the normal defrosting mode to execute defrosting operation.

Therefore, the defrosting control method of the air conditioner only aims at the outdoor coil temperature T caused by the change of the operation frequency F of the compressor _{Outer disc} The phenomena of frostless defrosting, frequent defrosting and the like which occur under the changed unsteady state can not influence the defrosting operation of the air conditioner when the outdoor coil is really in defrosting demand, and the air conditioner is more intelligent and can not influence the user experience.

By combining the above information, the temperature in the room is reduced and the temperature difference between the room temperature and the set temperature is increased, which causes the operation frequency F of the compressor to be rapidly increased, the operation frequency F of the compressor is changed to cause the fluctuation of the air conditioning system, and when the operation frequency F of the compressor is increased, the refrigerant supply of the outdoor heat exchanger is insufficient in a short time, which causes the evaporation pressure to be rapidly reduced, and further causes the temperature T of the outdoor coil pipe _{Outer disc} And rapidly decreases so that a defrost condition may be satisfied. And the air conditioning system fluctuation caused by the change of the operating frequency F of the compressor can be stabilized finally after a certain time, so that the outdoor heat exchange temperature difference is large and cannot reflect the actual frosting condition of the outdoor heat exchanger in the period that the operating frequency F of the compressor suddenly rises and is in a subsequent period of time, and further whether the defrosting condition is really achieved cannot be accurately judged. If only lead to Judging outdoor frosting condition by outdoor heat exchange temperature difference can cause false defrosting and frequent defrosting of the air conditioner, so that user comfort experience is reduced, and energy consumption is additionally increased.

Thus, a specific flow of the air conditioner defrosting control method according to an embodiment of the present invention can be described with reference to fig. 7 and 8, as shown in fig. 7, which is a flowchart of the air conditioner defrosting control method according to still another embodiment of the present invention, wherein the air conditioner defrosting control method includes steps S101 to S104, specifically as follows.

S101, the air conditioner operates in a heating mode.

S102, detecting that the compressor is continuously started to operate for a first preset time period, and acquiring the operating frequency of the compressor. The first operation time period can take a value of 10min.

S103, detecting that the operation frequency F of the compressor is increased, judging whether delta F & gtA is met, if yes, executing step S104, and entering a false defrosting mode; if the determination result is "no", the process returns to step S101, and the current heating mode is maintained.

In some embodiments of the present invention, as shown in fig. 8, a flowchart of a defrosting control method for an air conditioner according to still another embodiment of the present invention is shown, wherein the defrosting control method for an air conditioner further includes steps S105 to S113, which are specifically described below.

S105, the air conditioner operates in a false defrosting mode.

S106, judging whether the values of two or more consecutive times meet T _{Outer disc} (n+1)＜T _{Outer disc} (n) if the determination result is yes, step S107 is executed, and if the determination result is no, step S111 is executed, and the heating mode operation is maintained.

S107, judging whether the values of two or more consecutive times satisfy T _{Outer disc} (m+1)≥T _{Outer disc} (m) and recording that the time is tm and the operation frequency F of the compressor is F1, if the determination result is yes, step S108 is executed, and if the determination result is no, step S111 is executed.

S108, after tm time, continuously detecting the temperature T of the outdoor coil _{Outer disc} Judging whether the values of two or more consecutive times meet T _{Outer disc} (i+1)＜T _{Outer disc} (i) Or T _{Outer disc} (i+1)＝T _{Outer disc} (i) The operation frequency of the compressor is stable and F is less than or equal to F1, if the judgment result is yes, the step S109 is executed, and if the judgment result is no, the step S111 is executed.

S109, keeping the current heating mode, and exiting the false defrosting mode.

S110, entering a conventional heating mode.

S111, keeping the heating mode running.

S113, continuously judging whether T in three continuous periods is satisfied _{Outer disc} (n+1)＜T _{Outer disc} (n) if the determination result is "yes", the process returns to the execution of step S107, if the determination result is "no", the process proceeds to step S109, the current heating mode is maintained, the pseudo-defrosting mode is exited, and the normal heating mode is entered.

And, the outdoor coil temperature T is also detected when the above step S111 is performed _{Outer disc} And judges whether the values of two or more times continuously satisfy T _{Outer disc} (n+1)＜T _{Outer disc} (n) in other words, in the process of maintaining the operation of the heating mode, the defrosting control method of the air conditioner of the embodiment repeatedly executes the steps S106 to S113, so as to realize the cycle monitoring of the operation state of the air conditioner, and avoid the situations of defrosting without frost and frequent defrosting under the unsteady state of the system.

According to the defrosting control method of the air conditioner provided by the embodiment of the invention, the temperature T of the outdoor coil can be introduced on the basis of the outdoor environment temperature, the temperature of the outdoor coil, the temperature of the indoor coil, the temperature of the exhaust air and the like as parameters for controlling the air conditioner to enter the conventional defrosting mode _{Outer disc} And the running frequency F of the compressor is controlled to control the conditions of frostless defrosting and frequent defrosting when the running frequency F of the compressor is in an unsteady state, so that the control is more accurate, the extra energy consumption is avoided, and the user comfort experience is improved.

Other constructions and operations of the air conditioner 10 according to the embodiment of the present invention are known to those skilled in the art, and will not be described in detail herein.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An air conditioner, comprising:

a compressor and an outdoor heat exchanger;

the temperature sensor is arranged on the outdoor heat exchanger and is used for detecting the temperature of the outdoor coil;

a controller coupled to the compressor and the temperature sensor, the controller configured to:

when the air conditioner heats and operates, the operation frequency of the compressor is obtained, the increase value of the operation frequency in a preset period is determined to exceed a preset frequency threshold value, and the air conditioner is controlled to enter a false defrosting mode;

And under the pseudo defrosting mode, acquiring the outdoor coil temperature, determining that the outdoor coil temperature at the (n+1) th moment is smaller than the outdoor coil temperature at the n th moment, controlling the air conditioner to keep heating operation so as not to carry out outdoor defrosting, limiting that the outdoor environment temperature does not meet the condition of entering a conventional defrosting mode, further continuously determining that the outdoor coil temperature at the (m+1) th moment is not lower than the outdoor coil temperature at the m th moment for a first preset number of times, and controlling the air conditioner to keep heating operation continuously, wherein m and n are natural numbers, and the first preset number of times is more than or equal to 2.

2. The air conditioner of claim 1, wherein in the pseudo defrost mode, the controller is further configured to: the method includes the steps of recording an operating frequency of a compressor at a time when an outdoor coil temperature at an (m+1) th time is determined to be not lower than an outdoor coil temperature at an m-th time continuously a first preset number of times as a first frequency, starting from a time when an outdoor coil temperature at an (m+1) th time is determined to be not lower than an outdoor coil temperature at an m-th time continuously a first preset number of times, further determining that the outdoor coil temperature remains unchanged or determining that the outdoor coil temperature at an (i+1) th time is less than the outdoor coil temperature at an i-th time and the operating frequency of the compressor is not greater than the first frequency, controlling the air conditioner to exit the pseudo defrosting mode, continuing a heating operation, and canceling limitation of the outdoor environment temperature, wherein i > m.

3. The air conditioner of claim 2, wherein the controller is further configured to, upon determining that the outdoor coil temperature at the (i+1) th time is less than the outdoor coil temperature at the i th time, continuously determine that the outdoor coil temperature satisfies the outdoor coil temperature at the (i+1) th time less than the outdoor coil temperature at the i th time a second preset number of times, wherein the second preset number of times is not less than 2 times.

4. The air conditioner of claim 1, wherein the controller is further configured to: after determining that the outdoor coil temperature at the (n+1) th time is less than the outdoor coil temperature at the n-th time, further determining that the outdoor coil temperature rises again, the outdoor coil temperature remains unchanged after rising to a first temperature, and the duration of the outdoor coil temperature remaining unchanged after reaching the first time is reduced again to a second temperature, and the operating frequency of the compressor is increased to a second frequency unchanged, controlling the air conditioner to defrost outdoors and canceling the limitation of the outdoor environment temperature, wherein the second temperature reaches a defrost temperature.

5. The air conditioner according to any one of claims 1-4, wherein the controller is further configured to determine that the air conditioner is heating operation when the air conditioner is detected to start a heating mode of operation and a continuous operation time reaches a first preset time period, wherein 10min is equal to or less than the first preset time period.

6. A defrosting control method of an air conditioner, comprising:

detecting the heating operation of the air conditioner, and obtaining the operation frequency of a compressor;

determining that the increased value of the running frequency in a preset period exceeds a preset frequency threshold value, and controlling the air conditioner to enter a false defrosting mode;

acquiring an outdoor coil temperature from the moment of entering the pseudo defrosting mode, determining that the outdoor coil temperature at the (n+1) th moment is smaller than the outdoor coil temperature at the nth moment, controlling the air conditioner to keep heating operation so as not to perform outdoor defrosting, and limiting that the outdoor environment temperature does not meet the condition of entering the conventional defrosting mode, wherein n is a natural number;

further continuously determining that the temperature of the outdoor coil meets the temperature of the outdoor coil at the (m+1) th moment and is not lower than the temperature of the outdoor coil at the m th moment for a first preset number of times, and controlling the air conditioner to continuously keep heating operation, wherein m is a natural number, and the first preset number of times is more than or equal to 2 times.

7. The defrosting control method of claim 6, wherein after further continuously determining that the outdoor coil temperature satisfies the outdoor coil temperature at the (m+1) th time not lower than the outdoor coil temperature at the m-th time a first preset number of times, the control method further comprises:

Recording an operating frequency of the compressor at a time when the outdoor coil temperature at the (m+1) th time is determined not to be lower than the outdoor coil temperature at the m-th time continuously a first preset number of times as a first frequency;

further determining that the outdoor coil temperature remains unchanged or that the outdoor coil temperature at (i+1) th moment is less than the outdoor coil temperature at i moment and the operating frequency of the compressor is not greater than the first frequency, starting from a moment when the outdoor coil temperature at (m+1) th moment is determined not to be lower than the outdoor coil temperature at m moment continuously a first preset number of times, wherein i > m;

and controlling the air conditioner to exit the pseudo defrosting mode, continuing heating operation, and canceling limitation on the outdoor environment temperature.

8. The defrosting control method of claim 7, wherein determining that the outdoor coil temperature at the (i+1) th time is smaller than the outdoor coil temperature at the i th time comprises:

and continuously determining that the outdoor coil temperature meets the requirement that the outdoor coil temperature at the (i+1) time is smaller than the outdoor coil temperature at the i time for a second preset time, wherein the second preset time is more than or equal to 2 times.

9. The defrosting control method of claim 6, further comprising:

After determining that the outdoor coil temperature at the (n+1) th time is less than the outdoor coil temperature at the n-th time, further determining that the outdoor coil temperature rises again, the outdoor coil temperature remains unchanged after rising to a first temperature, and the duration of the outdoor coil temperature remaining unchanged after reaching the first time is reduced again to a second temperature, and the operating frequency of the compressor is increased to a second frequency unchanged, controlling the air conditioner to defrost outdoors and canceling the limitation of the outdoor environment temperature, wherein the second temperature reaches a defrost temperature.

10. The defrosting control method for an air conditioner as claimed in any one of claims 6 to 8, wherein detecting the heating operation of the air conditioner includes:

detecting that the air conditioner starts to operate a heating mode and the continuous operation time reaches a first preset duration, wherein 10min is less than or equal to the first preset duration.