CN115183400B

CN115183400B - Air conditioner and defrosting control method thereof

Info

Publication number: CN115183400B
Application number: CN202210760704.3A
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: CN115183400A

Abstract

The invention discloses an air conditioner and a defrosting control method of the air conditioner. Wherein, the air conditioner includes: a compressor, an indoor heat exchanger, an outdoor heat exchanger, a throttling device, an indoor fan, a first temperature sensor, a second temperature sensor, and a controller configured to: when the air conditioner heats and operates, the operation frequency of a compressor of the air conditioner 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; acquiring the temperature of an outdoor coil and the temperature of an indoor coil from the moment of entering a 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 n is a natural number; and when the temperature of the outdoor coil is kept unchanged within the first preset time period and the temperature of the coil and the indoor wind speed in the inner chamber are also kept unchanged within the first preset time period, controlling the air conditioner to exit the false defrosting mode.

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. Therefore, after the air conditioner operates for a period of time, the air conditioner needs to be timely and effectively defrosted. The current defrosting technology mainly comprises refrigeration mode (reverse circulation) defrosting, bypass defrosting and phase change energy storage defrosting.

In the related art, when the air conditioner is defrosted in a cooling mode, it is determined whether a defrosting condition is satisfied by using an outdoor ring temperature Tout, and an outdoor heat exchange temperature difference Δtout, where the outdoor heat exchange temperature difference Δtout=the outdoor ring temperature tout—the outdoor coil temperature T _{Outer disc} . In this way, on the occasion of entering the 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 enter a defrosting mode. However, at this time, no or very thin frost is formed on the outdoor heat exchanger, the heating capacity is very strong, and performing the defrosting mode 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, and can exit the false defrosting mode in time, thereby avoiding the extra energy consumption and ensuring 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: the device comprises a compressor, an indoor heat exchanger, an outdoor heat exchanger, a throttling device and an indoor fan; the first temperature sensor is used for acquiring the temperature of an indoor coil pipe of the indoor heat exchanger; the second temperature sensor is used for collecting the temperature of an outdoor coil pipe of the outdoor heat exchanger; a controller connected to the compressor, the first temperature sensor, and the second temperature sensor, respectively, the controller configured to: when the air conditioner heats and operates, the operation frequency of a compressor of the air conditioner 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; acquiring the outdoor coil temperature and the indoor 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, and controlling the air conditioner to keep heating operation so as not to defrost outdoors, wherein n is a natural number; and when the temperature of the outdoor coil is kept unchanged within a first preset time period and the temperature of the indoor coil and the indoor wind speed are also kept unchanged within the first preset time period, controlling the air conditioner to exit the false defrosting mode.

According to the air conditioner provided by the embodiment of the invention, the running frequency of the compressor is detected in real time, and the air conditioner is controlled to enter the false defrosting mode when the increased value of the running frequency of the compressor in the preset period exceeds the preset frequency threshold value. The first temperature sensor and the second temperature sensor are used for acquiring the indoor coil temperature and the outdoor coil temperature in real time, 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 pipe and the temperature of the indoor coil pipe are changed due to the change of the operation frequency of the compressor, and the control is more accurate. And after the fluctuation of the air conditioning system is determined to be stable, the air conditioner is timely controlled to exit the false defrosting mode to operate the conventional heating mode, 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 invention, the controller is configured to: when 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, the times that the outdoor coil temperature at the (n+1) th moment meets 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 are determined to reach the preset times, wherein the preset times are more than or equal to 2 times.

In some embodiments of the invention, the controller is configured to: and detecting that the air conditioner starts to operate a heating mode and the continuous operation time reaches a second preset time length, wherein the second preset time length is more than or equal to 9 minutes and less than or equal to 11 minutes.

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 is rising again after falling, the outdoor coil temperature is kept unchanged after rising to a first temperature, and the duration that the outdoor coil temperature is kept unchanged after reaching the first time is reduced again to a second temperature, and controlling the air conditioner to defrost outdoors when the operating frequency of the compressor is increased to the first frequency unchanged, wherein the second temperature reaches the defrosting temperature.

In some embodiments of the invention, 1s is less than or equal to the preset period is less than or equal to 1min, the preset frequency threshold is less than or equal to 3Hz, and 1min is less than or equal to the first preset time period is less than or equal to 5min.

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 a compressor of the air conditioner; 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 temperature of an outdoor coil and the temperature of an indoor 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 n is a natural number; and when the temperature of the outdoor coil is kept unchanged within a first preset time period and the temperature of the indoor coil and the indoor wind speed are also kept unchanged within the first preset time period, controlling the air conditioner to exit the false defrosting mode.

According to the defrosting control method of the air conditioner, a false defrosting mode is provided, and the defrosting mode of the air conditioner is not controlled under the unsteady state that the temperature of the outdoor coil, the temperature of the indoor coil and the indoor wind speed change caused by the change of the operating frequency of the compressor when the air conditioner is in heating operation, even if the temperature difference between the temperature of the outdoor coil and the outdoor heat exchange meets the condition of entering the defrosting mode. According to the method provided by the embodiment of the invention, the control parameter of the preset frequency threshold is introduced, when the fact that the increased value of the operation frequency of the compressor in the preset period exceeds the preset frequency threshold is detected, the air conditioner is controlled to enter the false defrosting mode, the temperature of the outdoor coil pipe and the temperature of the indoor coil pipe, which are caused by system fluctuation, are determined to be changed and then are stabilized again, the indoor air speed is unchanged, the air conditioner is controlled to timely exit the false defrosting mode to operate the conventional heating mode, the phenomenon control of defrosting without frost and frequent defrosting can be effectively avoided, the method is more accurate, the energy consumption is avoided, the experience of a user is ensured, and the requirements of the user on the comfort level under the heating working condition are met.

In some embodiments of the present invention, determining that the outdoor coil temperature at time (n+1) is less than the outdoor coil temperature at time n comprises: and determining that the continuous preset times of the outdoor coil temperature meet the condition that the outdoor coil temperature at the (n+1) th moment is smaller than the outdoor coil temperature at the nth moment, wherein the preset times are more than or equal to 2 times.

In some embodiments of the present invention, the air conditioner defrost control method further includes: 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 is rising again after falling, the outdoor coil temperature is kept unchanged after rising to a first temperature, and the duration that the outdoor coil temperature is kept unchanged after reaching the first time is reduced again to a second temperature, and controlling the air conditioner to defrost outdoors when the operating frequency of the compressor is increased to the first frequency unchanged, wherein the second temperature reaches the defrosting temperature.

In some embodiments of the present invention, detecting the heating operation of the air conditioner includes: and detecting that the air conditioner starts to operate a heating mode and the continuous operation time reaches a second preset time length, wherein the second preset time length is more than or equal to 9 minutes and less than or equal to 11 minutes.

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 of an air conditioner according to an embodiment of the present invention;

FIG. 4 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. 5 is a flowchart of a defrosting control method of an air conditioner according to an embodiment of the present invention;

fig. 6 is a flowchart of a defrosting control method of an air conditioner according to 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;

fig. 9 is a flowchart of a defrosting control method of an air conditioner according to still another embodiment of the present invention;

fig. 10 is a block diagram of an air conditioner according to another embodiment of the present invention.

Reference numerals:

an air conditioner 10;

a processor 101, a memory 102;

a compressor 1, an indoor heat exchanger 2, an outdoor heat exchanger 3, a throttling device 4, an indoor fan 5, a first temperature sensor 6, a second temperature sensor 7, a controller 8 and a four-way valve N.

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 user comfort experience 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 effectively defrosted in time, so that defrosting without frost or excessive frosting is avoided. When the refrigeration mode is adopted for defrosting, 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 user comfort experience 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 no or very thin frost is formed on the outdoor heat exchanger at this time, the heating capacity is very strong, and the defrosting mode is performed, the room temperature is greatly fluctuated, user comfort is lowered, and energy is additionally consumed.

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.

An outdoor unit of an air conditioner refers to a portion of a refrigeration cycle including a compressor and an outdoor heat exchanger, an 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 of the refrigeration cycle, and the air conditioner indoor unit may be provided with an indoor heat exchanger and an indoor fan.

In some embodiments of the present invention, an air conditioner according to an embodiment of the present invention may be described with reference to fig. 2 and 3. Wherein fig. 2 is a block diagram of an air conditioner according to an embodiment of the present invention; fig. 3 is a schematic view of an air conditioner according to an embodiment of the present invention.

As shown in fig. 2, the air conditioner 10 includes a compressor 1, an indoor heat exchanger 2, an outdoor heat exchanger 3, a throttle device 4, an indoor fan 5, a first temperature sensor 6, a second temperature sensor 7, a four-way valve N, and a controller 8 (not shown in fig. 3), wherein the connection between the compressor 1, the indoor heat exchanger 2, the outdoor heat exchanger 3, the throttle device 4, the indoor fan 5, the first temperature sensor 6, the second temperature sensor 7, and the four-way valve N is not shown in fig. 2.

The throttling device 4 is used for realizing a refrigerant pressure adjusting function under a refrigerating condition or a heating condition of the air conditioner 10. When the air conditioner 10 operates under different working conditions, the flow direction of the refrigerant in the system pipeline can be changed through the four-way valve N, so that the mutual conversion between the refrigeration and the heating of the air conditioner 10 is realized.

Under heating conditions, the indoor fan 5 is used for blowing air heated by the indoor heat exchanger 2 into a room during operation, wherein the indoor fan 5 and the indoor heat exchanger 2 shown in fig. 2 and 3 are both disposed in the indoor unit, but specific disposition positions of the indoor fan 5 and the indoor heat exchanger 2 are not limited.

In an embodiment, as shown in fig. 3, the direction of the solid arrow indicates the flow direction of the refrigerant in the system pipeline in the cooling condition of the air conditioner 10, and the flow direction of the refrigerant in the system pipeline in the cooling condition is the compressor 1-the four-way valve N-the outdoor heat exchanger 3-the throttling device 4-the indoor heat exchanger 2-the compressor 1. For the air conditioner 10 using the refrigeration mode to defrost, when the air conditioner 10 operates in the defrost mode, the flow direction of the refrigerant in the system pipeline is the same as the flow direction of the refrigerant in the refrigeration mode. The direction of the dashed arrow indicates the flow direction of the refrigerant in the system piping of the air conditioner 10 under heating conditions. Under the heating working condition, the flow direction of the refrigerant in the system pipeline is the compressor 1-the four-way valve N-the indoor heat exchanger 2-the throttling device 4-the outdoor heat exchanger 3-the compressor 1.

When the air conditioner 10 is operated under the cooling condition and the heating condition, the circulation directions of the refrigerant gas in the air conditioner 10 are different, that is, when the air conditioner 10 is operated in the defrosting mode and the heating mode, the circulation directions of the refrigerant gas in the air conditioner 10 are also different, and the switching process between the heating mode and the defrosting mode of the air conditioner 10 is similar to the switching process between the cooling mode and the heating mode, and the mode switching can be realized through the four-way valve N arranged outdoors.

The first temperature sensor 6 is arranged on a coil of the indoor heat exchanger 2, for example, inside the indoor heat exchanger 2 as shown in fig. 3, for acquiring the indoor coil temperature T of the indoor heat exchanger 2 _{Inner disc} . A second temperature sensor 7 is arranged on the coil of the outdoor heat exchanger 3, for example inside the outdoor heat exchanger 3 as shown in fig. 3, for detecting the outdoor coil temperature T of the outdoor heat exchanger 3 _{Outer disc} 。

The controller 8 is connected with the compressor 1, the first temperature sensor 6 and the second temperature sensor 7 respectively for acquiring the operating frequency F of the compressor 1 and the indoor coil temperature T _{Inner disc} And outdoor coil temperature T _{Outer disc} . The controller 8 may be a Processor with data processing and analysis functions, such as a CPU (Central Processing Unit/Processor, central processing unit) in the air conditioner 10, and the controller 8 may include a monitoring unit, a judging unit, a control unit, and the like for implementing data processing and analysis.

In an embodiment, the controller 8 is configured to: when the air conditioner 10 is in heating operation, the operating frequency F of the compressor 1 of the air conditioner 10 is acquired.

In the embodiment, when the air conditioner 10 is just started to operate, after a period of time of the start-up operation, the system tends to be in a steady state, and the operating frequency F of the compressor 1 is stabilized. Specifically, it may be set that the heating mode of the air conditioner 10 is detected to be started and the continuous operation time reaches the second preset duration, that is, it is determined that the air conditioner 10 is operated to be heated. For a general air conditioner 10, the compressor 1 may tend to be in a stable state after being started and operated for 10min, the second preset duration may be set to be less than or equal to 9min and less than or equal to 11min, if the heating operation state of the air conditioner 10 is detected when the second preset duration is less than or equal to 9min, the operation frequency of the compressor 1 is not stable, and the collected data may influence the judgment result. If the heating operation state of the air conditioner 10 is detected after more than 11 minutes, the waiting time is too long, so that the second preset time period may be set to 9 minutes, 10 minutes, 11 minutes, or the like.

Wherein the operating frequency of the compressor 1 can be denoted F. When the air conditioner 10 is operated in the heating mode, the operation frequency F of the compressor 1 is suddenly increased when the indoor environment temperature is reduced or the user controls the air conditioner 10 to change from a silent low-wind mode to a high-wind mode or the user controls the air conditioner 10 to change from a sleep mode or a silent mode to a normal heating mode in the process of actually using the air conditioner 10 by the user, and the operation state of the compressor 1 can be monitored in real time by detecting the operation frequency F of the compressor 1.

In some embodiments of the present invention, it is determined that the increased value of the operating frequency F 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 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 unit coil temperature to drop suddenly.

Specifically, referring to fig. 4, as shown in fig. 4, a schematic diagram of an outdoor coil temperature affected by an operation frequency of a compressor according to an embodiment of the present invention is shown, wherein the outdoor coil temperature is denoted as T _{Outer disc} Line in the figureM represents the change condition of the operation frequency F of the compressor along with 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 compressor operating frequency F suddenly increases and the outdoor unit coil temperature T _{Outer disc} Starts to fall and falls to the lowest at the time T1, if the temperature T of the coil pipe of the outdoor unit at the time _{Outer disc} Has been reduced to meet the conditions for entering defrost mode. But at this time, the coil temperature T of the outdoor unit _{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 environment temperature if the air conditioner is still operated in the defrost mode. However, the user controls the air conditioner 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 enters the defrosting mode and the user will be against, the user comfort experience is reduced, and if the air conditioner frequently has the frost-free defrosting phenomenon, the user experience is poor, and even user complaints can be caused.

And, as indicated by line N, the outdoor unit 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 defrosting mode, the air conditioner needs to exit the defrosting mode again at the moment to continue to operate the heating mode. In the process, the air conditioner can not achieve the corresponding defrosting effect when briefly operating in the defrosting mode, and energy is additionally consumed.

Therefore, based on the above situation, 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, the operating frequency F of the compressor may slightly fluctuate due to various reasons, and if the preset frequency threshold a is set to a smaller value, the air conditioner frequently enters the false defrosting mode, which may cause 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 operating frequency F of the compressor 1 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 can be understood that, by setting the preset period t to a small value, the change of the operating frequency F of the compressor in a short time can be detected in real time.

When the operating frequency F of the compressor 1 suddenly increases, an operating frequency fsteup of the compressor 1 needs to be calculated. The frequency increment, i.e. the increment value of the operating frequency of the compressor, may be 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 the increment value of the operating frequency of the compressor 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 defrosting mode by mistake, the air conditioner can be controlled to enter the false defrosting mode at this time, and then whether the air conditioner needs to be controlled to operate the defrosting mode is further determined.

In some embodiments of the present invention, the outdoor coil temperature and the indoor coil temperature are acquired from the time of entering the pseudo-defrost mode, 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, and the air conditioner is controlled to keep the heating operation so as not to perform the outdoor defrost, wherein n is a natural number.

For example, as shown by line N in fig. 4, starting at time T0, the operating frequency F of the compressor suddenly increases, and the outdoor unit coil temperature T _{Outer disc} When the falling starts, the time t0 is recorded as the time when the pseudo defrosting mode is entered.

Wherein, the temperature of the indoor coil pipe is recorded as T _{Inner disc} The outdoor coil temperature at time (n+1) is denoted 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 the parameter characterizing the fluctuation of the air conditioning system is the indoor coil temperature T _{Inner disc} Temperature T of outdoor coil _{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. Wherein, "++number represents a strong correlation degree, i.e., the more" ++number affects the degree more,

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 versus the indoor coil temperature T _{Inner disc} And outdoor coil temperature T _{Outer disc} Has a great influence on the indoor coil temperature T, and _{inner disc} Is greatly influenced by the temperature T of the indoor coil, and is based on the indoor wind speed _{Inner disc} Temperature T of outdoor coil _{Outer disc} And the running frequency F of the compressor controls the conditions of frostless defrosting and frequent defrosting of the air conditioner, 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 11 suddenly changes, the indoor coil temperature T is inevitably caused _{Inner disc} And outdoor coil temperature T _{Outer disc} When the temperature of the outdoor coil T is changed, the temperature T of the outdoor coil T is necessarily also generated when the air conditioner starts to enter the false defrosting mode _{Outer disc} The decrease, i.e. from the time when the pseudo-defrost mode was initially entered, i.e. time T0, is checked for 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). But at this time the outdoor coil temperature T _{Outer disc} The rapid decrease is mainly caused by the increase of the operating frequency F of the compressor 1, which causes the short-time occurrence of insufficient refrigerant supply of the outdoor heat exchanger, which in turn causes the rapid decrease of the evaporating pressure, and when the outdoor coil temperature T _{Outer disc} The rapid decrease also inevitably causes the indoor coil temperature T _{Inner disc} Rise or remain unchanged, thus the indoor coil temperature T _{Inner disc} The state of the air conditioning system can be effectively represented to a certain extent. If the outdoor frosting condition is judged only by the temperature difference of the outdoor heat exchangerIn the case that the operating frequency F of the compressor 1 suddenly rises and the time of the following period such as time T0 to time T1, the outdoor heat exchange temperature difference is large, which cannot reflect the actual frosting condition of the outdoor heat exchanger, and it cannot be accurately determined whether the operating frequency F has actually reached the defrosting condition, if the operating frequency F is at this time, the outdoor coil temperature T is used as the temperature of the outdoor coil _{Outer disc} Lowering the condition for controlling the air conditioner to enter the defrosting mode may lead to misjudgment, and may lead to the air conditioner still entering the defrosting mode by mistake. Referring to line N in FIG. 2, 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, without judging the temperature T of the outdoor coil _{Outer disc} Whether the condition of entering the defrosting mode is met or not, the air conditioner is controlled not to enter the defrosting mode and continuously operates the heating mode at the moment, the condition that the indoor environment temperature is reduced due to the fact that the air conditioner enters the defrosting mode by mistake can be effectively avoided, and the condition that the user experience is influenced is avoided.

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 some embodiments of the invention, when the outdoor coil temperature T _{Outer disc} The coil temperature T in the inner chamber remains unchanged for a first preset period of time and is maintained for a first preset period of time _{Outer disc} And the indoor wind speed is also kept unchanged, the air conditioner 10 is controlled to exit the false defrosting mode.

Different first preset durations 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 duration is less than or equal to 1min and less than or equal to 5min, for example, the first preset duration can be 1min or 2min or 3min or 4min or 5min, and the like. Specifically, as shown by line Q in fig. 4, after time t2, when detectingOutdoor coil temperature T _{Outer disc} Which remains unchanged during a first preset period of time, then indicates the outdoor coil temperature T _{Outer disc} After falling, rise again and have stabilized and at the outdoor coil temperature T _{Outer disc} During the constant time period, the indoor coil temperature T _{Inner disc} And the indoor air speed is kept unchanged, if the conditions are met, the air conditioner system is characterized to be stable at the moment, and the air conditioner is controlled to exit the false defrosting mode and enter the conventional heating mode. If the conditions can not be fully met, the air conditioner system is characterized as not reaching a stable state at the moment, and the air conditioner continues to continue to control the temperature T of the outdoor coil pipe _{Outer disc} Temperature T of indoor coil pipe _{Inner disc} And periodically detecting the indoor wind speed and keeping the current heating mode to operate. By detecting the temperature T of the coil outside the inner chamber of the preset period _{Outer disc} Temperature T of indoor coil pipe _{Inner disc} And indoor wind speed, and find the outdoor coil temperature T _{Outer disc} At the lowest point of the outdoor coil temperature T _{Outer disc} And the judgment of whether the defrosting condition is met or not is stopped before stable operation after rising, so that the occurrence of false defrosting can be effectively avoided.

According to the air conditioner 10 of the embodiment of the invention, the air conditioner is controlled to enter the false defrosting mode by detecting the operating frequency F of the compressor in real time and determining that the added value delta F of the operating frequency F of the compressor in a preset period exceeds the preset frequency threshold A. The first temperature sensor 6 and the second temperature sensor 7 are used for acquiring the indoor coil temperature T in real time _{Inner disc} And outdoor coil temperature T _{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} Temperature T of indoor coil pipe _{Inner 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 after the air conditioning system is determined to be fluctuated and tends to be stable, the air conditioner 10 is timely controlled to exit the false defrosting mode to operate 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 the present inventionIn some embodiments, the controller 8 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} Rising after falling, the outdoor coil temperature T _{Outer disc} Is kept unchanged after rising to the first temperature, and the outdoor coil temperature T _{Outer disc} The duration of keeping the first temperature unchanged reaches the first duration and then decreases to the second temperature, and the operating frequency F of the compressor 1 increases to the first frequency unchanged, and the air conditioner 10 is controlled to defrost outdoors, 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, the operating frequency F of the compressor suddenly increases from time T0, and the outdoor unit 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 and after the time T2, the temperature T of the coil pipe of the outdoor unit _{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 the line Q in fig. 4, 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 defrosting mode is 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 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 at the moment. 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 removal of the air conditioner when the outdoor coil really has defrosting requirementsThe frost operation is more intelligent, and the user experience sense can not be influenced.

A defrosting control method of an air conditioner according to an embodiment of the present invention will be described with reference to fig. 5 to 10. 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. 5, 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 a compressor of the air conditioner.

In an embodiment, when the air conditioner is just started to operate, after a period of time of starting operation, the system tends to be in a stable state, and the operation frequency of the compressor is stable. Specifically, it may be set that the heating mode of the air conditioner is detected to be started and the continuous operation time reaches the second preset duration, that is, the heating operation of the air conditioner is determined. For a general air conditioner, the compressor can tend to a stable state after being started to run for 10min, the second preset time length can be set to be less than or equal to 9min and less than or equal to 11min, if the heating running state of the air conditioner is detected when the second preset time length is less than 9min, the running frequency of the compressor is unstable, and the acquired data is unstable and possibly influences the judging result. If the temperature is higher than 11min, the waiting time is too long due to the fact that the heating operation state of the air conditioner is detected, and therefore the second preset time length can be set to be 9min or 10min or 11 min.

Wherein the operating frequency of the compressor may be denoted by F. When the air conditioner is operated in the heating mode, in the process of actually using the air conditioner by a user, when the indoor environment temperature is reduced or the air conditioner is controlled by the user to be changed from a mute mode and a low wind mode to a high wind mode, or the air conditioner is controlled by the user to be changed from a sleep mode or a mute mode to a conventional heating mode, the operation frequency F of the compressor can suddenly rise, and the operation state of the compressor can be monitored in real time by detecting the operation frequency F of the compressor.

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.

Specifically, it will be described with reference to fig. 4, in which, as indicated by line N, starting at time T0, the operating frequency F of the compressor suddenly increases, and the outdoor unit coil temperature T _{Outer disc} Starts to fall and falls to the lowest at the time T1, if the temperature T of the coil pipe of the outdoor unit at the time _{Outer disc} Has been reduced to meet the conditions for entering defrost mode. But at this time, the coil temperature T of the outdoor unit _{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 environment temperature if the air conditioner is still operated in the defrost mode. However, the user controls the air conditioner 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 enters the defrosting mode and the user will be against, the user comfort experience is reduced, and if the air conditioner frequently has the frost-free defrosting phenomenon, the user experience is poor, and even user complaints can be caused.

And when the air conditioner operates in a heating mode, the operation frequency F of the compressor is obtained once at regular intervals. 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 can be understood that, by setting the preset period t to a small value, the change of the operating frequency F of the compressor in a short time can be detected in real time.

When the operating frequency F of the compressor suddenly increases, an operating frequency fstep of the compressor needs to be calculated. The frequency increment, i.e. the increment value of the operating frequency of the compressor, may be 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 the increment value of the operating frequency of the compressor 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 defrosting mode by mistake, the air conditioner can be controlled to enter the false defrosting mode at this time, and then whether the air conditioner needs to be controlled to operate the defrosting mode is further determined.

S3, acquiring the temperature of the outdoor coil and the temperature of the indoor 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 n is a natural number.

Specifically, when the operating frequency F of the compressor suddenly increases, the air conditioning system inevitably fluctuates, and the parameter characterizing the fluctuation of the air conditioning system is the indoor coil temperature T _{Inner disc} Temperature T of outdoor coil _{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, it is inevitable to cause the indoor coil temperature T _{Inner disc} And outdoor coil temperature T _{Outer disc} When the air conditioner starts to enter the false defrosting modeThe outdoor coil temperature T will also necessarily occur _{Outer disc} The decrease, i.e. from the time when the pseudo-defrost mode was initially entered, i.e. time T0, is checked for 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). But at this time the outdoor coil temperature T _{Outer disc} The main reason is that the operation frequency F of the compressor is increased, so that the refrigerant supply of the outdoor heat exchanger is insufficient in a short time, the evaporation pressure is reduced rapidly, and the temperature T of the outdoor coil is reduced _{Outer disc} The rapid decrease also inevitably causes the indoor coil temperature T _{Inner disc} Rise or remain unchanged, thus the indoor coil temperature T _{Inner disc} The state of the air conditioning system can be effectively represented to a certain extent. If the outdoor frosting condition is judged only by the temperature difference of the outdoor heat exchanger, the outdoor heat exchange temperature difference is large and cannot reflect the real frosting condition of the outdoor heat exchanger, whether the outdoor frosting condition really reaches the defrosting condition cannot be accurately judged, if the operating frequency F of the compressor suddenly rises and the time of the following period such as the time T0 to the time T1, the outdoor coil temperature T is used at the moment _{Outer disc} Lowering the condition for controlling the air conditioner to enter the defrosting mode may lead to misjudgment, and may lead to the air conditioner still entering the defrosting mode by mistake. Referring to line N in FIG. 2, 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, without judging the temperature T of the outdoor coil _{Outer disc} Whether the condition of entering the defrosting mode is met or not, the air conditioner is controlled not to enter the defrosting mode and continuously operates the heating mode at the moment, the condition that the indoor environment temperature is reduced due to the fact that the air conditioner enters the defrosting mode by mistake can be effectively avoided, and the condition that the user experience is influenced is avoided.

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 of detection, for example, the number of times may be preset to be 2 or more times, for example, the preset number of times may be 2 or 3 timesOr 4 times, i.e. by applying a temperature T to 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.

And S4, when the temperature of the outdoor coil is kept unchanged within a first preset time period and the temperature of the coil and the indoor wind speed in the inner chamber are also kept unchanged within the first preset time period, controlling the air conditioner to exit the false defrosting mode.

Different first preset durations 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 duration is less than or equal to 1min and less than or equal to 5min, for example, the first preset duration can be 1min or 2min or 3min or 4min or 5min, and the like. Specifically, as shown by line Q in FIG. 2, after time T2, when the outdoor coil temperature T is sensed _{Outer disc} Which remains unchanged during a first preset period of time, then indicates the outdoor coil temperature T _{Outer disc} After falling, rise again and have stabilized and at the outdoor coil temperature T _{Outer disc} During the constant time period, the indoor coil temperature T _{Inner disc} And the indoor air speed is kept unchanged, if the conditions are met, the air conditioner system is characterized to be stable at the moment, and the air conditioner is controlled to exit the false defrosting mode and enter the conventional heating mode. If the conditions can not be fully met, the air conditioner system is characterized as not reaching a stable state at the moment, and the air conditioner continues to continue to control the temperature T of the outdoor coil pipe _{Outer disc} Temperature T of indoor coil pipe _{Inner disc} And periodically detecting the indoor wind speed and keeping the current heating mode to operate. By detecting the temperature T of the coil outside the inner chamber of the preset period _{Outer disc} Temperature T of indoor coil pipe _{Inner disc} And indoor wind speed, and find the outdoor coil temperature T _{Outer disc} At the lowest point of the outdoor coil temperature T _{Outer disc} And the judgment of whether the defrosting condition is met or not is stopped before stable operation after rising, so that the occurrence of false defrosting can be effectively avoided.

According to the defrosting control method of the air conditioner provided by the embodiment of the invention, a false defrosting mode is provided, and when the air conditioner is in heating operation, the temperature T of the outdoor coil is caused by the change of the operating frequency F of the compressor _{Outer disc} Temperature T of indoor coil pipe _{Inner disc} And indoor spaceIn unsteady state with varying wind speed, even at outdoor coil temperature T _{Outer disc} And the outdoor heat exchange temperature difference delta Tout meets the condition of entering the defrosting mode, and the air conditioner is not controlled to operate in the defrosting mode. The method of the embodiment of the invention introduces a control parameter of a preset frequency threshold A, controls an air conditioner to enter a false defrosting mode when detecting that the increment delta F of the operating frequency F of the compressor in a preset period exceeds the preset frequency threshold A, and determines the temperature T of an outdoor coil pipe caused by system fluctuation _{Outer disc} Temperature T of indoor coil pipe _{Inner disc} After the change, the indoor air speed is stable again and is unchanged at the moment, the air conditioner is controlled to timely exit the false defrosting mode to operate the conventional heating mode, frostless defrosting and frequent defrosting phenomenon control can be effectively avoided, the air conditioner is more accurate, extra energy consumption is avoided, the experience of a user is ensured, and the requirement of the user on comfort level 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 defrosting control method for an air conditioner 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 is increased again after being decreased, the outdoor coil temperature is kept unchanged after being increased to reach the first temperature, the duration of keeping the first temperature unchanged for the first time is reduced again to the second temperature, and the operating frequency of the compressor is increased to be unchanged at the first frequency, and controlling the air conditioner to conduct outdoor defrosting, 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. 4, the operating frequency F of the compressor suddenly increases from time T0, and the outdoor unit 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 and after the time T2, the temperature T of the coil pipe of the outdoor unit _{Outer disc} Will return to the second temperature and atRemains 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 the line Q in fig. 4, 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 defrosting mode is 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 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 at the moment. 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.

In some embodiments of the present invention, as shown in fig. 7, a flowchart of a defrosting control method for an air conditioner according to still another embodiment of the present invention is shown, wherein after detecting a heating operation of the air conditioner, the defrosting control method for an air conditioner further includes at least one of step S11 and step S12, specifically as follows.

S11, detecting that the indoor temperature is reduced and the temperature difference between the indoor temperature and the set temperature is increased.

For example, when a user uses the air conditioner to perform heating operation for a period of time, the indoor temperature gradually rises, the set temperature difference is smaller and smaller, wherein the set temperature difference=room temperature-set temperature, the smaller the set temperature difference is, the closer the room temperature is to the set temperature, the air conditioner is gradually cooled from the initial high-frequency operation to the middle-low frequency operation, and when the user set temperature requirement is met, the middle-low frequency operation is maintained. During the period that the air conditioner keeps the medium-low frequency operation, the frequent opening and closing of the door or the personnel change can cause the indoor temperature to be reduced, so that the set temperature difference is increased, and the air conditioner can be operated again in an ascending frequency mode. When air conditioner When the operating frequency F of the compressor of (a) suddenly increases, the outdoor coil temperature T _{Outer disc} Will quickly decrease and lower than the outdoor coil temperature T in high frequency stable operation _{Outer disc} . At this time, if the temperature difference and the operation time of the outdoor heat exchange are according to the conventional temperature difference, the temperature T of the outdoor coil pipe can be determined _{Outer disc} If the defrosting condition is met, the outdoor unit is easy to enter a defrosting mode, such as a defrosting mode, and at the moment, no frost or small quantity of frost possibly exists on the outdoor unit, and if defrosting operation is performed at the moment, the indoor temperature is reduced, so that the user comfort experience is affected.

S12, detecting the increase of the wind speed of the indoor fan.

For example, when the air conditioner is operated in the heating condition and in the mute or sleep mode, the compressor is operated at low frequency, and the fan is operated at low wind speed, if the indoor temperature requirement is not met after the air conditioner is operated in the operation mode for a period of time, if the user feels colder, the air conditioner is controlled to be adjusted to be operated in the conventional heating mode, and at the moment, the wind speed of the fan is changed from low wind to high wind, and the operation frequency F of the compressor is also increased rapidly.

For another example, when the user starts up and operates for a period of time by using high wind or strong wind, the temperature of the indoor coil pipe rises, the power of the air conditioner increases, at this time, the current protection or the overload protection of the inner disc may be triggered to generate the frequency reduction phenomenon, the air conditioner is further changed into a low wind mode, the compressor keeps running at a low frequency, and when the air conditioning system keeps running at a low frequency, the evaporating temperature is higher at this time, the frost is not easy to be formed, and the frost amount of the outdoor unit is generally little or not. When the compressor keeps running at low frequency for a period of time, if the user changes to adjust the wind speed to high wind or strong wind again, the protection mode is released, and the running frequency F of the compressor is rapidly increased.

By combining the above information, the decrease of the indoor temperature and the increase of the temperature difference between the indoor temperature and the set temperature, and the increase of the wind speed of the indoor fan can lead to the rapid increase of the operating frequency F of the compressor, the change of the operating frequency F of the compressor leads to the fluctuation of the air conditioning system, and when the operating frequency F of the compressor is increased, the refrigerant supply of the outdoor heat exchanger is insufficient in a short time, the evaporation pressure can be rapidly reduced, and the temperature T of the outdoor coil is further caused _{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 the outdoor frosting condition is judged only through the outdoor heat exchange temperature difference, the phenomenon of false defrosting and frequent defrosting of the air conditioner can be caused, the comfort experience of a user is reduced, and the 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. 8 and 9, as shown in fig. 8, 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 second preset time period, and acquiring the operating frequency of the compressor. Wherein, the second operation time length 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. Wherein A is a preset frequency threshold, and A is more than or equal to 3Hz.

In some embodiments of the present invention, as shown in fig. 9, a flowchart of a defrosting control method for an air conditioner according to another embodiment of the present invention is shown, wherein the defrosting control method for an air conditioner further includes steps S105 to S112, 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 without entering the defrosting mode, and the heating mode is maintainedAnd (3) operating in a formula.

S107, continuously detecting T _{Outer disc} 、T _{Inner disc} And indoor wind speed, judging whether T is satisfied _{Outer disc} 、T _{Inner disc} And the indoor wind speed is kept unchanged within a first preset time period, if the judgment result is yes, the temperature T of the outdoor coil is represented _{Outer disc} After falling, the system is stable, and the step S110 is executed, if the judgment result is NO, the system is not stable, and the T is continued _{Outer disc} 、T _{Inner disc} And detecting the indoor wind speed. Wherein, the first preset time period can be set to be 5min.

S110, continuously judging whether T in three continuous periods is met _{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, the outdoor coil temperature T is indicated _{Outer disc} If the temperature is not lowered, the step S108 is executed, the pseudo defrosting mode is exited, the step S109 is executed, and the normal heating mode is entered.

The defrosting control method of the air conditioner provided by the embodiment of the invention can be used for controlling the outdoor environment temperature and the outdoor coil pipe temperature T _{Outer disc} Temperature T of indoor coil pipe _{Inner disc} On the basis of using exhaust temperature and indoor wind speed as parameters for controlling defrosting mode, the operation frequency F of compressor and outdoor coil pipe temperature T are introduced _{Outer disc} Temperature T of indoor coil pipe _{Inner disc} And the indoor wind speed so as to control the conditions of frostless defrosting and frequent defrosting of the compressor when the running frequency F of the compressor is in an unsteady state, the control is more accurate, the extra energy consumption is avoided, and the user comfort experience is improved.

In some embodiments of the present invention, an air conditioner 10 employing the method of the above embodiment is also provided, as shown in fig. 10, which is a block diagram of an air conditioner according to an embodiment of the present invention, wherein the air conditioner 10 includes at least one processor 101 and a memory 102.

The memory 102 is communicatively connected to the at least one processor 101, and a computer program executable by the at least one processor 101 is stored in the memory 102, and the at least one processor 101 implements any one of the above defrosting control methods when executing the computer program.

According to the air conditioner 10 provided by the embodiment of the invention, the defrosting control method of the air conditioner of the above embodiment is realized when the at least one processor 101 executes the computer program stored in the memory 102, by adopting the method, the phenomena of defrosting and frequent defrosting of the air conditioner 10 without frost can be effectively avoided, the control is more accurate, 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.

And, the defrosting control method of the air conditioner of the embodiment is applied to the air conditioner 10, so that the frost-free defrosting and frequent defrosting conditions which are easy to occur in the unsteady state of the air conditioning system can be controlled more effectively without increasing hardware cost, the extra energy consumption is avoided, and the method has important significance for the intelligent development of the air conditioner 10.

Other constructions and operations of the air conditioner 10 and the like 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:

the device comprises a compressor, an indoor heat exchanger, an outdoor heat exchanger, a throttling device and an indoor fan;

the first temperature sensor is used for acquiring the temperature of an indoor coil pipe of the indoor heat exchanger;

the second temperature sensor is used for collecting the temperature of an outdoor coil pipe of the outdoor heat exchanger;

a controller connected to the compressor, the first temperature sensor, and the second temperature sensor, respectively, the controller configured to:

when the air conditioner heats and operates, the operation frequency of a compressor of the air conditioner 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;

acquiring the outdoor coil temperature and the indoor 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, and controlling the air conditioner to keep heating operation so as not to defrost outdoors, wherein n is a natural number;

and when the temperature of the outdoor coil is kept unchanged within a first preset time period and the temperature of the indoor coil and the indoor wind speed are also kept unchanged within the first preset time period, controlling the air conditioner to exit the false defrosting mode.

2. The air conditioner of claim 1, wherein the controller is configured to: when 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, the times that the outdoor coil temperature at the (n+1) th moment meets 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 are determined to reach the preset times, wherein the preset times are more than or equal to 2 times.

3. The air conditioner of claim 1, wherein the controller is configured to: and detecting that the air conditioner starts to operate a heating mode and the continuous operation time reaches a second preset time length, wherein the second preset time length is more than or equal to 9 minutes and less than or equal to 11 minutes.

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 is rising again after falling, the outdoor coil temperature is kept unchanged after rising to a first temperature, and the duration that the outdoor coil temperature is kept unchanged after reaching the first time is reduced again to a second temperature, and controlling the air conditioner to defrost outdoors when the operating frequency of the compressor is increased to the first frequency unchanged, wherein the second temperature reaches the defrosting temperature.

5. The air conditioner according to claim 1, wherein 1s is equal to or less than the preset period is equal to or less than 1min, the preset frequency threshold is equal to or more than 3hz, and 1min is equal to or less than the first preset time period is equal to or less than 5min.

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

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

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 temperature of an outdoor coil and the temperature of an indoor 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 n is a natural number;

7. The defrosting control method of claim 6, wherein determining that the outdoor coil temperature at the (n+1) th time is smaller than the outdoor coil temperature at the n-th time comprises:

And determining that the continuous preset times of the outdoor coil temperature meet the condition that the outdoor coil temperature at the (n+1) th moment is smaller than the outdoor coil temperature at the nth moment, wherein the preset times are more than or equal to 2 times.

8. The defrosting control method of an air conditioner as set forth in claim 6, wherein 1s is equal to or less than 1min of the preset period, the preset frequency threshold is equal to or more than 3hz, and 1min is equal to or less than 5min of the first preset duration.

9. The defrosting control method of an air conditioner as set forth in 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 is rising again after falling, the outdoor coil temperature is kept unchanged after rising to a first temperature, and the duration that the outdoor coil temperature is kept unchanged after reaching the first time is reduced again to a second temperature, and controlling the air conditioner to defrost outdoors when the operating frequency of the compressor is increased to the first frequency unchanged, wherein the second temperature reaches the defrosting 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:

And detecting that the air conditioner starts to operate a heating mode and the continuous operation time reaches a second preset time length, wherein the second preset time length is more than or equal to 9 minutes and less than or equal to 11 minutes.