CN111189184A

CN111189184A - Air conditioner and anti-freezing control method thereof

Info

Publication number: CN111189184A
Application number: CN201811352389.0A
Authority: CN
Inventors: 许文明
Original assignee: Qingdao Haier Air Conditioner Gen Corp Ltd
Current assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Haier Smart Home Co Ltd
Priority date: 2018-11-14
Filing date: 2018-11-14
Publication date: 2020-05-22
Anticipated expiration: 2038-11-14
Also published as: CN111189184B

Abstract

The invention discloses an air conditioner and an anti-freezing control method thereof, and belongs to the technical field of air conditioners. The control method comprises the following steps: acquiring the current working current, the temperature of an inner coil, the air inlet temperature and the air outlet temperature of an inner fan when the air conditioner operates in the current working mode in response to receiving a trigger signal for detecting whether the air conditioner has a freezing problem; determining whether the air conditioner has a freezing problem or not according to the current working current of the inner fan, the temperature of the inner coil, the air inlet temperature and the air outlet temperature; and when the freezing problem of the air conditioner is determined, the anti-freezing operation corresponding to the anti-freezing mode is determined to be started according to the current working current and the temperature of the inner coil. The air conditioner and the anti-freezing control method thereof can judge the freezing condition of the air conditioner according to the working current, the air inlet temperature, the air outlet temperature and the temperature of the inner coil of the inner fan of the air conditioner, and can timely control the air conditioner to protect the indoor heat exchanger from freezing when the freezing problem of the air conditioner can be judged; the control method for preventing the freezing can enable the air conditioner to trigger the freezing prevention protection of the air conditioner more timely and sensitively.

Description

Air conditioner and anti-freezing control method thereof

Technical Field

The invention relates to the technical field of air conditioners, in particular to an air conditioner and an anti-freezing control method thereof.

Background

When the air conditioner is used for refrigerating or dehumidifying, the outer surface of the indoor heat exchanger is always in a lower temperature state due to the temperature angle of the refrigerant entering the indoor heat exchanger of the indoor unit, when indoor air flows through the indoor heat exchanger, water vapor in the air is easily condensed into dew or even frost on the indoor heat exchanger, so that the indoor heat exchanger of the indoor unit is frozen, the refrigerating effect of the air conditioner is influenced, and the refrigerating or dehumidifying capacity of the air conditioner is weaker and weaker.

For the freezing phenomenon of an indoor heat exchanger of an air conditioner, an anti-freezing implementation mode mainly adopted by the existing air conditioner is to detect the temperature of a coil by using a temperature sensor installed on the coil of the indoor heat exchanger, so that the air conditioner can judge whether the indoor heat exchanger is frozen or not according to the temperature of the coil of an indoor unit, and when the coil of the indoor unit is frozen, the air conditioner can timely treat the freezing phenomenon. However, the existing air conditioner is generally only provided with a single temperature sensor at the middle position of an indoor heat exchanger of an indoor unit of the air conditioner, and whether the freezing problem exists is judged only through the value of a single temperature parameter detected by the temperature sensor, and because the low-temperature refrigerant flows through a plurality of branch pipe flow paths of the indoor heat exchanger, when the branch pipe flow path position at a non-middle position freezes, the temperature sensor arranged at the middle position is not sensitive to the low-temperature sensing of the temperature sensor, which easily causes the whole freezing problem of the indoor heat exchanger of the air conditioner to be serious and then is easily sensed by the temperature sensor, so that the requirement of the air conditioner on timely and sensitive triggering of anti-freezing protection of the air conditioner cannot be met.

Disclosure of Invention

The invention provides an air conditioner and an anti-freezing method thereof, aiming at solving the defect that the traditional air conditioner is insensitive to anti-freezing protection triggering caused by adopting a single temperature sensor to sense the temperature of a coil. The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview and is intended to neither identify key/critical elements nor delineate the scope of such embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

According to a first aspect of the present invention, there is provided a control method for preventing freezing of an air conditioner, the control method comprising:

acquiring the current working current, the temperature of an inner coil, the air inlet temperature and the air outlet temperature of an inner fan when the air conditioner operates in the current working mode in response to receiving a trigger signal for detecting whether the air conditioner has a freezing problem;

determining whether the air conditioner has a freezing problem or not according to the current working current of the inner fan, the temperature of the inner coil, the air inlet temperature and the air outlet temperature; and when the freezing problem of the air conditioner is determined, the anti-freezing operation corresponding to the anti-freezing mode is determined to be started according to the current working current and the temperature of the inner coil.

In an alternative embodiment, determining whether the air conditioner has a freezing problem according to the current working current of the inner fan, the temperature of the inner coil, the temperature of the inlet air and the temperature of the outlet air comprises:

if the current working current of the inner fan is smaller than a preset first current threshold value, the temperature of the inner coil is larger than a preset freezing temperature threshold value, and the temperature difference value between the inlet air temperature and the outlet air temperature is smaller than a preset temperature difference threshold value, determining that the air conditioner does not have the freezing problem; otherwise, determining that the air conditioner has a freezing problem;

the first current threshold is used for representing the critical current of the corresponding inner fan when the air conditioner has a freezing problem.

In an alternative embodiment, in response to determining that the air conditioner has a freezing problem, the air conditioner switches to an anti-freeze mode;

determining the anti-freezing operation corresponding to the anti-freezing mode according to the current working current and the temperature of the inner coil, wherein the anti-freezing operation comprises the following steps:

if the current working current of the inner fan is greater than or equal to a preset first current threshold and less than a preset second current threshold, and the temperature of the inner coil is less than or equal to a preset freezing temperature threshold, the anti-freezing operation corresponding to the anti-freezing mode comprises the steps of increasing the opening degree of the throttling device and reducing the current frequency of the compressor to a first preset frequency; the first preset frequency is the product of the current frequency of the compressor and a first preset proportion, and the second current threshold is used for representing that the indoor heat exchanger of the air conditioner achieves a first icing degree;

if the current working current of the inner fan is greater than or equal to a preset second current threshold value and less than or equal to a preset third current threshold value, and the temperature of the inner coil is less than or equal to a preset freezing temperature threshold value, the anti-freezing operation corresponding to the anti-freezing mode comprises the step of reducing the current frequency of the compressor to a second preset frequency; the second preset frequency is the product of the current frequency of the compressor and a second preset proportion, and the third current threshold is used for representing that the indoor heat exchanger of the air conditioner reaches a second icing degree; the second preset proportion is smaller than the first preset proportion, and the second icing degree is larger than the first icing degree;

and if the current working current of the inner fan is greater than a preset third current threshold value and the temperature of the inner coil is less than or equal to a preset freezing temperature threshold value, the anti-freezing operation corresponding to the anti-freezing mode comprises controlling the air conditioner to stop.

In an optional embodiment, the control method further comprises:

after the air conditioner executes the anti-freezing operation and lasts for a set time, acquiring the working current of an internal fan when the air conditioner runs in the current working mode;

re-determining whether the air conditioner has a freezing problem or not according to the working current of the inner fan, the temperature of the inner coil, the air inlet temperature and the air outlet temperature;

and if the air conditioner is determined not to have the freezing problem, controlling the air conditioner to exit the anti-freezing mode.

In an optional implementation manner, after responding to the trigger signal, before obtaining the current working current of the inner fan, the temperature of the inner coil, the temperature of the inlet air and the temperature of the outlet air when the air conditioner operates in the current working mode, the control method further includes:

and controlling to switch the air deflector of the indoor unit of the air conditioner to the maximum air outlet angle.

According to the second aspect of the present invention, there is also provided an air conditioner, the air conditioner comprising an air conditioner body and a controller, the controller being configured to:

In an alternative embodiment, the controller is specifically configured to:

In an alternative embodiment, the controller is further configured to switch the air conditioner to the freeze prevention mode in response to determining that the air conditioner has a freezing problem;

the controller is specifically configured to:

In an alternative embodiment, the controller is further configured to:

In an optional implementation manner, the controller is further configured to control to switch an air deflector of an indoor unit of the air conditioner to a maximum air outlet angle after responding to the trigger signal and before acquiring a current working current, an inner coil temperature, an air inlet temperature, and an air outlet temperature of the inner fan when the air conditioner operates in the current working mode.

The air conditioner and the anti-freezing control method thereof can judge the freezing condition of the air conditioner according to the working current, the air inlet temperature, the air outlet temperature and the temperature of the inner coil of the inner fan of the air conditioner, and can timely control the air conditioner to protect the indoor heat exchanger from freezing when the freezing problem of the air conditioner can be judged; the control method for preventing the freezing can enable the air conditioner to trigger the freezing prevention protection of the air conditioner more timely and sensitively.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a schematic flow chart diagram illustrating a method for controlling freeze prevention of an air conditioner according to an exemplary embodiment of the present invention;

FIG. 2 is a flowchart illustrating a control method for preventing freezing of an air conditioner according to the present invention, in accordance with still another exemplary embodiment;

FIG. 3 is a flowchart illustrating a control method for preventing freezing of an air conditioner according to the present invention, in accordance with still another exemplary embodiment;

FIG. 4 is a flowchart illustrating a control method for preventing freezing of an air conditioner according to the present invention, in accordance with still another exemplary embodiment;

FIG. 5 is a flowchart illustrating a control method for preventing freezing of an air conditioner according to the present invention, in accordance with still another exemplary embodiment;

FIG. 6 is a flowchart illustrating a control method for preventing freezing of an air conditioner according to the present invention, in accordance with still another exemplary embodiment;

FIG. 7 is a flowchart illustrating a control method for preventing freezing of an air conditioner according to the present invention, in accordance with still another exemplary embodiment;

FIG. 8 is a flowchart illustrating a control method for preventing freezing of an air conditioner according to the present invention, in accordance with still another exemplary embodiment;

fig. 9 is a flowchart illustrating a control method for preventing freezing of an air conditioner according to another exemplary embodiment of the present invention.

Detailed Description

The following description and the drawings sufficiently illustrate specific embodiments of the invention to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. The examples merely typify possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in or substituted for those of others. The scope of embodiments of the invention encompasses the full ambit of the claims, as well as all available equivalents of the claims. Embodiments may be referred to herein, individually or collectively, by the term "invention" merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept if more than one is in fact disclosed. Herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method or apparatus that comprises the element. The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. As for the methods, products and the like disclosed by the embodiments, the description is simple because the methods correspond to the method parts disclosed by the embodiments, and the related parts can be referred to the method parts for description.

Fig. 1 is a control method for preventing freezing of an air conditioner according to the present invention, according to an exemplary embodiment.

As shown in fig. 1, the invention provides a control method for preventing freezing of an air conditioner, which can be used for solving the problem that the air outlet and heat exchange efficiency are affected due to freezing of a heat exchange tube of an indoor heat exchanger caused by a low-temperature refrigerant when the air conditioner operates in a refrigeration or dehumidification mode; the following mainly takes the anti-freezing protection in the cooling mode as an example, but it should be understood that other working modes of the air conditioner, which may cause the freezing problem of the indoor heat exchanger, may also apply the anti-freezing control method of the present invention; specifically, the method mainly comprises the following steps:

s101, acquiring the air inlet temperature, the air outlet temperature and the temperature of an inner coil of an indoor unit when the air conditioner operates in a refrigeration mode;

as an optional embodiment, a temperature sensor is respectively arranged at an air inlet and an air outlet of an indoor unit of the air conditioner, and the temperature sensors can be respectively used for detecting the real-time inlet air temperature of the air inlet and the real-time outlet air temperature of the air outlet of the indoor unit; step S101, the temperature data detected by the two sensors are used as the inlet air temperature and the outlet air temperature;

meanwhile, a coil pipe position of an indoor heat exchanger of the air conditioner is provided with a temperature sensor, and the temperature sensor can be used for detecting the real-time temperature of the coil pipe position; in step S101, the real-time temperature of the coil position detected by the temperature sensor is used as the temperature of the inner coil of the current control process.

S102, calculating a temperature difference value between an inlet air temperature and an outlet air temperature;

taking the absolute value of the temperature difference between the inlet air temperature and the outlet air temperature;

s103, determining that the indoor heat exchanger of the air conditioner has a freezing problem in response to the fact that the temperature difference between the inlet air temperature and the outlet air temperature is larger than a preset difference threshold value and the temperature of the inner coil is smaller than a preset temperature threshold value.

The preset difference threshold and the preset temperature threshold are preset threshold parameters of the air conditioner and are used for representing whether the indoor unit of the air conditioner has a freezing problem or not; if the temperature difference between the air temperature and the air outlet temperature is larger than a preset difference threshold value and the temperature of the inner coil is smaller than a preset temperature threshold value, the temperature of the inner coil is reduced at the moment at a higher speed, and further the freezing quantity and the freezing speed of the indoor unit can be judged to be higher, and at the moment, the air conditioner needs to perform anti-freezing treatment on the indoor unit; otherwise, the speed of the temperature drop of the inner coil is slower, so that the freezing quantity of the indoor unit is less and the freezing speed is slower, and at the moment, the air conditioner does not need to perform anti-freezing treatment on the indoor unit temporarily.

Optionally, the difference threshold value is 10 ℃; the temperature threshold value is 5 ℃.

Therefore, in step S103, the current freezing condition of the indoor unit is determined by comparing the temperature difference value with the difference threshold value and comparing the temperature of the inner coil with the temperature threshold value, so as to further determine whether the air conditioner needs to be switched to the anti-freezing mode.

Optionally, the method for controlling freezing prevention of an air conditioner of the present invention further comprises: and controlling the air conditioner to switch to an anti-freezing mode in response to determining that the indoor heat exchanger of the air conditioner has a freezing problem.

Specifically, the freeze prevention mode switched by the air conditioner includes: sequentially executing a plurality of periodic flows defining anti-freezing operations, the periodic flows sequentially including a first periodic flow defining one or more anti-freezing operations to increase an opening degree of a throttle device, a second periodic flow defining one or more anti-freezing operations to decrease a frequency of a compressor, and a third periodic flow defining one or more anti-freezing operations to control a shutdown of an air conditioner;

here, each cycle flow has a set cycle duration; optionally, the cycle durations of the plurality of cycle flows are sequentially reduced.

For example, when the temperature change rate of the temperature of the inner coil is greater than the set rate threshold value, the air conditioner performs the anti-freezing operation defined by the first periodic flow, that is, in the first periodic flow, the opening value of the throttling device is increased to the set value, and the time for maintaining the throttling device at the set opening value is 30 min; the first periodic flow may be performed only 1 time, or, alternatively, continuously performed a plurality of times; then, the air conditioner executes the anti-freezing operation defined by the second period process, namely in the second period process, the frequency value setting frequency value of the compressor is reduced, the running time of the compressor for maintaining the setting frequency value is set to be 10min, and the set time is the second period time; the second cycle flow may be executed only 1 time, or may be continuously executed a plurality of times; and then, the air conditioner executes the anti-freezing operation defined by the third periodic flow, namely in the third periodic flow, the air conditioner is controlled to stop, and the stop time of the air conditioner is set to be 2min, wherein the set time is the third periodic time.

Here, it is redetermined whether there is a freezing problem in the indoor heat exchanger of the air conditioner after the execution of the flow is completed every cycle; after the process is executed in each period, executing step S101 to step S103 again, if the newly determined indoor heat exchanger of the air conditioner does not have the freezing problem, exiting the anti-freezing mode, and at this time, switching the air conditioner back to the original working mode, such as the cooling mode; and if the newly determined indoor heat exchanger of the air conditioner still has the freezing problem, continuously executing the anti-freezing mode according to the original sequence.

In the second periodic flow of the anti-freezing mode, the frequency of the compressor of the air conditioner can be subjected to frequency reduction operation at a set frequency reduction amplitude, so that the frequency reduction amplitude of the compressor can be ensured to be adaptive to the current requirement for anti-freezing protection, and meanwhile, the original frequency can be quickly recovered after the air conditioner finishes the anti-freezing mode; the control method for preventing freezing of the air conditioner further comprises the following steps: and obtaining the attenuation speed of the temperature of the inner coil and the temperature of the inner coil, and matching according to a preset incidence relation to obtain the frequency reduction amplitude of the compressor of the second period process, wherein the incidence relation is used for representing the corresponding relation between the attenuation speed of the temperature of the inner coil and the frequency reduction amplitude.

For example, the air conditioner prestores a corresponding relationship between the attenuation speed for representing the temperature of the inner coil, the temperature of the inner coil and the frequency reduction amplitude, and the correlation relationship can be measured through an experiment before the air conditioner leaves a factory. Before the air conditioner leaves a factory, the defrosting and deicing conditions of the indoor heat exchanger and the time length for the compressor to recover the original frequency after the compressor performs frequency reduction at different amplitudes under the conditions of different attenuation speeds of the temperature of the inner coil and the temperature of the inner coil can be measured and calculated in a simulation experiment mode; and establishing a corresponding relation between the attenuation speed of the temperature of the inner coil, the temperature of the inner coil and the frequency reduction amplitude with the optimal defrosting and deicing time and the shortest restoration time of the compressor according to the measured experimental data.

For example, the association relationship between the two may include: when the decay rate of the temperature of the inner coil is 1.5 ℃/6min and the temperature of the inner coil is less than 7 ℃, the frequency reduction amplitude of the compressor is 20 Hz; when the decay rate of the temperature of the inner coil is 1.2 ℃/6min and the temperature of the inner coil is less than 7 ℃, the frequency reduction amplitude of the compressor is 15 Hz; when the decay rate of the temperature of the inner coil is 1 ℃/6min and the temperature of the inner coil is less than 7 ℃, the frequency reduction amplitude of the compressor is 10 Hz; here, in the pre-stored correspondence, the decay rate of the temperature of the inner coil in the correlation is positively correlated with the frequency reduction amplitude.

Optionally, the anti-freezing mode for switching the air conditioner may further include controlling the air conditioner to switch to a heating mode for operation; when the air conditioner is switched to the heating mode to operate, high-temperature refrigerant discharged by a compressor of the air conditioner flows into the indoor heat exchanger first, the surface temperature of the indoor heat exchanger can be raised by utilizing the heat of the refrigerant, so that frost frozen on the outer surface of the outdoor heat exchanger is melted, and the aim of preventing the air conditioner from freezing is fulfilled.

Here, the air conditioner is operated for a set period of time when switched to the heating mode. Optionally, the specific duration of the set duration is determined according to the temperature of the internal coil detected in step S101, where the specific duration of the set duration and the coil temperature are in a negative correlation relationship, that is, the lower the coil temperature is, the more serious the freezing problem of the air conditioner is, the longer the specific duration of the set duration is, so as to ensure that the air conditioner has enough time to defrost and melt ice for the indoor heat exchanger; and the higher the coil temperature is, the lighter the freezing problem of the air conditioner is, and the shorter the specific time length of the set time length is.

Or, the air conditioner can also adopt other anti-freezing modes in the prior art to perform anti-freezing protection on the indoor heat exchanger of the air conditioner.

In the present embodiment, the operation mode of the air conditioner includes a cooling mode, a heating mode, and the like. In a refrigeration mode, a low-temperature refrigerant flows into the indoor heat exchanger, and the indoor heat exchanger can be frozen under the conditions of low temperature of the refrigerant, overlarge flow rate of the refrigerant and the like; in the heating mode, a high-temperature refrigerant flows into the indoor heat exchanger, and the overall heat load of the air conditioner is high under the conditions of overhigh temperature and overlarge flow of the refrigerant, so that the safe operation of the air conditioner is influenced.

Here, in the conventional air conditioner, the determination of the freezing prevention and the determination of the thermal load protection are performed with high accuracy using the temperature of the refrigerant flowing into the indoor heat exchanger as a reference parameter. In the control flow of the invention, the invention can also utilize the temperature of the inner coil pipe detected by the temperature sensor arranged on the air conditioner to carry out load protection. Therefore, the process of the invention can not only judge the anti-freezing protection of the indoor heat exchanger according to the temperature of the coil; meanwhile, the heat load protection operation in the heating mode can be realized according to the temperature of the inner coil without being limited to the temperature parameter detected by the sensor which is arranged on the high-temperature refrigerant inflow pipe orifice of the indoor heat exchanger.

Specifically, for the problem of load protection in the heating mode, the control method of the present invention further includes: when the current working mode of the air conditioner is a heating mode, acquiring the exhaust temperature of a compressor and the temperature of an inner coil of an indoor heat exchanger; determining the cold-medium temperature according to the exhaust temperature of the compressor and the temperature of an inner coil of the indoor heat exchanger; and performing load protection operation on the air conditioner according to the cold and medium temperature.

Here, the related operation flow of the air conditioner load protection may be applied to a flow of starting a heating mode when the air conditioner is started in severe cold weather in winter, and may also be applied to the load protection operation when the heating mode is used for anti-freezing protection.

In this embodiment, the exhaust pipe orifice of the compressor of the air conditioner is further provided with another temperature sensor, and the temperature sensor can be used for detecting the obtained exhaust temperature of the compressor; meanwhile, the coil temperature is also detected by the temperature sensor arranged on the indoor heat exchanger of the indoor unit.

Optionally, determining the cold-medium temperature according to the discharge temperature of the compressor and the temperature of the inner coil of the indoor heat exchanger, includes: the cold medium temperature is calculated according to the following formula,

Tcoi l＝A*Td+B*Tc+D，

wherein Tcoi is the cold medium temperature, Td is the discharge temperature of the compressor, Tc is the inner coil temperature of the indoor heat exchanger, a is a first calculated coefficient associated with the discharge temperature, B is a second calculated coefficient associated with the coil temperature, and D is a calculated constant.

Optionally, in the load protection operation of the air conditioner according to the cold-medium temperature, whether the air conditioner needs to perform the load protection operation or not can be judged according to the cold-medium temperature; when it is determined that the air conditioner needs to perform the load protection operation, the air conditioner performs a responsive load protection operation.

In this embodiment, determining whether the air conditioner needs to perform the load protection operation according to the cold-medium temperature may specifically include: and comparing the cold medium temperature with a preset temperature threshold value, and determining whether the air conditioner needs to perform load protection operation according to the comparison result. Specifically, when the temperature in the cold air is greater than or equal to a preset temperature threshold, determining that the air conditioner needs to perform load protection operation; and when the cold-medium temperature is smaller than the preset temperature threshold value, determining that the air conditioner does not need to carry out load protection operation.

Optionally, the load protection operation performed by the air conditioner may include: reducing the operating frequency of the compressor, increasing the rotating speed of an inner fan of the indoor unit, increasing the flow opening of the throttling device, and the like. Alternatively, the air conditioner may also employ other load protection operations in the prior art to protect the safe operation of the heating mode of the air conditioner.

Fig. 2 is a control method for preventing freezing of an air conditioner according to the present invention, shown in accordance with still another exemplary embodiment.

As shown in fig. 2, the present invention further provides another control method for preventing freezing of an air conditioner, which can also be used to solve the problem that the air-out efficiency and the heat exchange efficiency are affected by freezing of a heat exchange tube of an indoor heat exchanger caused by a low-temperature refrigerant when the air conditioner operates in a refrigeration or dehumidification mode; specifically, the method mainly comprises the following steps:

s201, acquiring the air inlet temperature, the air outlet temperature and the temperature of an inner coil of an indoor unit when the air conditioner operates in a refrigeration mode;

in this embodiment, the specific execution process of step S201 may refer to step S201 in the foregoing, which is not described herein again;

s202, determining the temperature change rate of the temperature of the inner coil;

as an alternative embodiment, in order to determine the temperature change rate of the inner coil temperature in step S202, at least three inner coil temperatures may be sequentially detected at set time intervals in step S201, and the temperature difference between two inner coil temperatures that are adjacent in sequence is calculated respectively;

here, the time intervals are set to 1min, 2min, 5min, and so on.

Taking the set time interval as 1min as an example, detecting the temperature t0 of the inner coil pipe with the number 1 after the process is started; after 1min, detecting the temperature t1 of the inner coil pipe with the number 2 again; after another 1min interval, the inner coil temperature t2 of number 3 was detected.

Thus, the temperature difference between the two inner coil temperatures adjacent in sequence is calculated, wherein △ t1 is t1-t0, △ t2 is t2-t 1;

further, the difference between the two temperature differences in the order of adjacency was calculated to obtain a temperature change rate of (△ t2- △ t 1).

S203, calculating a temperature difference between the inlet air temperature and the outlet air temperature;

s204, in response to the fact that the temperature difference value between the air inlet temperature and the air outlet temperature is larger than a preset difference threshold value, the temperature change rate of the temperature of the inner coil pipe is larger than a set rate threshold value, and the temperature of the inner coil pipe is smaller than a preset temperature threshold value, it is determined that the indoor heat exchanger of the air conditioner has the freezing problem.

The air conditioner and the anti-freezing control method thereof can judge the freezing condition of the air conditioner according to the air inlet temperature, the air outlet temperature and the temperature of the inner coil pipe of the air conditioner, and can control the air conditioner to perform anti-freezing protection on the indoor heat exchanger in time when the freezing problem of the air conditioner can be judged; the control method for preventing the air conditioner from freezing can enable the air conditioner to trigger self anti-freezing protection more timely and sensitively, and ensures the safe and stable operation of the air conditioner.

Optionally, the freeze prevention mode switched by the air conditioner of the present invention includes: sequentially executing a plurality of periodic flows defining anti-freezing operations, the periodic flows sequentially including a first periodic flow defining one or more anti-freezing operations to increase an opening degree of a throttle device, a second periodic flow defining one or more anti-freezing operations to decrease a frequency of a compressor, and a third periodic flow defining one or more anti-freezing operations to control a shutdown of an air conditioner; re-determining whether the indoor heat exchanger of the air conditioner has a freezing problem after the execution of each cycle flow is completed; and if the newly determined indoor heat exchanger of the air conditioner has no freezing problem, exiting the anti-freezing mode. The specific execution flow of the above-mentioned anti-freeze mode may refer to the technical content disclosed in the corresponding part of the embodiment shown in fig. 1, and is not described herein again.

Optionally, the method for controlling freezing prevention of an air conditioner of the present invention further comprises: and acquiring the attenuation speed of the temperature of the inner coil and the temperature of the inner coil, and matching according to a preset incidence relation to obtain the frequency reduction amplitude of the compressor of the corresponding second period process, wherein the incidence relation is used for representing the corresponding relation between the attenuation speed of the temperature of the inner coil, the temperature of the inner coil and the frequency reduction amplitude. The decay rate of the inner coil temperature in the correlation is positively correlated with the magnitude of the downconversion. The specific flow of determining the frequency reduction amplitude of the compressor may refer to technical content disclosed in the corresponding part of the embodiment shown in fig. 1, and is not described herein again.

Or, the anti-freezing mode of the air conditioner switching can also comprise controlling the air conditioner to be switched to the heating mode for operation. Here, for the specific execution flow of switching the air conditioner to the heating mode and the load protection operation when the air conditioner operates in the heating mode, reference may be made to the technical contents disclosed in the foregoing embodiments, and details are not described herein.

Fig. 3 is a control method for preventing freezing of an air conditioner according to the present invention, shown in accordance with still another exemplary embodiment.

As shown in fig. 3, the present invention further provides another control method for preventing freezing of an air conditioner, which can also be used to solve the problem that the air-out efficiency and the heat exchange efficiency are affected by freezing of a heat exchange tube of an indoor heat exchanger caused by a low-temperature refrigerant when the air conditioner operates in a refrigeration or dehumidification mode; specifically, the method mainly comprises the following steps:

s301, responding to a received trigger signal for detecting whether the air conditioner has a freezing problem, and acquiring a first working current of an inner fan, a first air inlet temperature and a first air outlet temperature of an indoor unit when the air conditioner runs in a current working mode;

optionally, the air conditioner may preset a trigger signal for detecting whether the air conditioner has a freezing problem when the air conditioner operates in a specific mode (e.g., a refrigeration mode), for example, after the air conditioner is set to operate in the refrigeration mode, the trigger signal for detecting the freezing problem is generated every half an hour;

or, a remote controller or a control panel of the air conditioner provides an instruction input mode for performing anti-freezing detection by user input; a user can send a trigger signal for detecting whether the air conditioner has a freezing problem or not to the air conditioner by operating a mode related to the anti-freezing detection of the remote controller or the control panel;

here, the air conditioner is provided with a motor for driving the inner fan to operate, and the first working current in step S301 is a real-time working current of the motor in the current working mode;

optionally, the current working mode in step S301 is a cooling mode or a dehumidification mode, and the like, which are prone to cause a freezing problem inside the indoor unit;

here, the specific execution process of the first inlet air temperature and the first outlet air temperature of the indoor unit may refer to step S101 in the foregoing, which is not described herein again;

s302, determining whether the air conditioner has a freezing problem or not according to the first working current of the inner fan, the first air inlet temperature and the first air outlet temperature of the indoor unit.

Optionally, in step S302, it is determined whether the air conditioner has a freezing problem according to a first working current of the inner fan, a first inlet air temperature of the indoor unit, and a first outlet air temperature, and the specific process includes: and if the ratio of the first working current of the inner fan to the preset reference current is smaller than a preset ratio threshold value, and the temperature difference value between the first air inlet temperature and the first air outlet temperature is larger than a preset first temperature difference threshold value, determining that the indoor heat exchanger of the air conditioner has the freezing problem.

The reference current is a current parameter preset by the air conditioner and used for representing the current value of the inner fan under the condition that the air conditioner does not have the freezing problem; here, before the air conditioner leaves the factory, the current standard value I b of the motor under different inner fan gears in the non-frozen state of the air conditioner can be measured by means of test and determination, for example, the current standard value of the high wind gear is Ib1, the current standard value of the medium wind gear is I b2, the current standard value of the low wind gear is I b3, and the like; therefore, the invention can prestore the plurality of current standard values in the air conditioner as the reference current; here, when step S302 is executed, a corresponding current standard value may be obtained by searching and matching according to a currently set inner fan gear, and the current standard value is used as a reference current for calculating with the first operating current in step S302;

optionally, the value of the ratio threshold is 0.9;

for example, the reference current matched with a certain inner fan gear is I b, the first operating current of the inner fan acquired in step S301 is I S, and when I S/I b is less than 0.9, it may be determined that a judgment sub-condition related to the current parameter when performing the air conditioner freezing judgment is satisfied; when I s/I b is not less than 0.9, it is judged that the judgment sub-condition concerning the current parameter at the time of the air conditioner freezing judgment is not satisfied.

The first temperature difference threshold is also a preset threshold parameter of the air conditioner, and optionally, the value of the first temperature difference threshold is 10 ℃;

the air conditioner and the anti-freezing control method thereof can judge the freezing condition of the air conditioner according to the working current, the air inlet temperature and the air outlet temperature of an inner fan of the air conditioner, and can timely control the air conditioner to perform anti-freezing protection on an indoor heat exchanger when the freezing problem of the air conditioner can be judged; the control method for preventing the air conditioner from freezing can enable the air conditioner to trigger self anti-freezing protection more timely and sensitively, and ensures the safe and stable operation of the air conditioner.

The control method for preventing freezing of the air conditioner further comprises the following steps: in response to determining that the indoor heat exchanger of the air conditioner has a freezing problem, controlling the air conditioner to switch to an anti-freezing mode; when the air conditioner determines that the indoor heat exchanger of the air conditioner has the freezing problem, the freezing problem of the indoor unit of the air conditioner can be prevented from being further aggravated by switching the anti-freezing mode, the amount of frozen frost on the indoor heat exchanger can be reduced, and the stable and safe operation of the air conditioner can be guaranteed.

Optionally, the freeze prevention mode for switching the air conditioner includes: controlling to reduce the current frequency of the compressor to a preset frequency, wherein the preset frequency is the product of the current frequency of the compressor and a preset proportion.

Here, the frequency of the compressor is reduced, the amount of refrigerant in a refrigerant circulation pipeline conveyed to the air conditioner by the compressor can be reduced, and the exhaust temperature is reduced; therefore, the quantity of the refrigerant flowing into the indoor heat exchanger through the refrigerant circulating pipeline is reduced, the liquid inlet temperature is increased, and the temperature condition that the indoor heat exchanger of the air conditioner generates frost freezing can be effectively improved.

Optionally, the value of the preset frequency is 0.8; that is, after the air conditioner is switched to the anti-freezing mode, the frequency of the compressor is reduced to 80% of the original frequency.

Optionally, the method for controlling freezing prevention of an air conditioner of the present invention further comprises: after the air conditioner executes the anti-freezing operation and lasts for a set time, acquiring a second working current of an internal fan, a second air inlet temperature and a second air outlet temperature of an indoor unit when the air conditioner runs in a current working mode; if the second working current is equal to the preset reference current and the temperature difference value between the second inlet air temperature and the second outlet air temperature is smaller than a preset second temperature difference threshold value, controlling the air conditioner to exit the anti-freezing mode;

after the air conditioner executes the anti-freezing operation and continues to set the duration, the freezing condition of the air conditioner is judged for the second time again by using the detection and judgment process, the air conditioner exits from the anti-freezing mode after meeting the preset condition, and the air conditioner is switched back to the working mode before the air conditioner executes the anti-freezing mode, such as the refrigeration mode; therefore, the influence of the air conditioner to execute the anti-freezing mode on the originally set refrigeration and cooling requirements of the user can be reduced, and the use experience of the user is improved.

Here, the specific obtaining manner of the second working current, the second inlet air temperature and the second outlet air temperature may refer to step S301 in the foregoing, and is not described herein again.

The second temperature difference threshold is smaller than the first temperature difference threshold; optionally, the value of the second temperature difference threshold is 5 ℃.

In addition, optionally, after the triggering signal is responded, before the first working current of the inner fan, the first inlet air temperature of the indoor unit and the first outlet air temperature of the indoor unit when the air conditioner operates in the current working mode are obtained, the control method further includes: and controlling to switch the air deflector of the indoor unit of the air conditioner to the maximum air outlet angle. Here, when the air deflector of the air conditioner is at different air outlet angles, the air outlet volume of the air conditioner is also affected, and further certain interference influence is caused on the air outlet temperature of the air conditioner, the current of the inner fan and the like, so that in order to ensure the accuracy of judging the anti-freezing problem of the air conditioner, the air deflector of the air conditioner is switched to the maximum air outlet angle before the first working current of the inner fan, the first air inlet temperature of the indoor unit and the first air outlet temperature of the air conditioner are obtained when the air conditioner operates in the current working mode, and therefore the air conditioner can perform air outlet at the maximum air outlet volume, and the detection accuracy of relevant parameters is improved.

Here, in the above test calculation process of the reference current required by the air conditioner, the air deflector of the air conditioner is also kept at the maximum air outlet angle position.

Fig. 4 is a control method for preventing freezing of an air conditioner according to the present invention, which is shown in accordance with still another exemplary embodiment.

As shown in fig. 4, the present invention further provides another control method for preventing freezing of an air conditioner, which can also be used to solve the problem that the air-out efficiency and the heat exchange efficiency are affected by freezing of a heat exchange tube of an indoor heat exchanger caused by a low-temperature refrigerant when the air conditioner operates in a refrigeration or dehumidification mode; specifically, the method mainly comprises the following steps:

s401, responding to a received trigger signal for detecting whether the air conditioner has a freezing problem, and acquiring a first working current of an inner fan, a first air inlet temperature of an indoor unit, a first air outlet temperature and an inner coil temperature when the air conditioner runs in a current working mode;

in this embodiment, in step S401, in addition to detecting the first operating current, the first inlet air temperature and the first outlet air temperature by using the content disclosed in step S301, the indoor heat exchanger of the indoor unit is further provided with another temperature sensor, and the temperature sensor can be used for sensing the real-time temperature of the inner coil of the indoor heat exchanger, so that the real-time temperature of the inner coil detected by the temperature sensor is used as the temperature of the inner coil in step S401;

s402, determining whether the air conditioner has a freezing problem or not according to the first working current of the inner fan, the first air inlet temperature, the first air outlet temperature and the temperature of the inner coil pipe of the indoor unit.

Optionally, in step S402, determining whether the air conditioner has a freezing problem according to a first working current of the inner fan, a first inlet air temperature of the indoor unit, and a first outlet air temperature, which may specifically include: if the ratio of the first working current of the inner fan to the preset reference current is smaller than a preset ratio threshold value, the temperature difference value between the first air inlet temperature and the first air outlet temperature is larger than a preset first temperature difference threshold value, and the temperature of the inner coil is smaller than a preset freezing temperature threshold value, the indoor heat exchanger of the air conditioner is determined to have the freezing problem.

Here, for a specific execution flow in which the ratio of the first working current of the inner fan to the preset reference current is smaller than the preset ratio threshold, and the temperature difference between the first inlet air temperature and the first outlet air temperature is greater than the preset first temperature difference threshold, reference may be made to the technical content of the corresponding part of the embodiment shown in fig. 3, and details are not repeated here.

The freezing temperature threshold is a threshold parameter pre-stored in the air conditioner, and optionally, the value of the freezing temperature threshold is 0 ℃.

The air conditioner and the anti-freezing control method thereof can judge the freezing condition of the air conditioner according to the working current, the air inlet temperature, the air outlet temperature and the temperature of the inner coil of the inner fan of the air conditioner, and can timely control the air conditioner to protect the indoor heat exchanger from freezing when the freezing problem of the air conditioner can be judged; the control method for preventing the air conditioner from freezing can enable the air conditioner to trigger self anti-freezing protection more timely and sensitively, and ensures the safe and stable operation of the air conditioner.

Optionally, the method for controlling freezing prevention of an air conditioner of the present invention further comprises: in response to determining that the indoor heat exchanger of the air conditioner has a freezing problem, controlling the air conditioner to switch to an anti-freezing mode;

wherein the freeze prevention mode includes: controlling to reduce the current frequency of the compressor to a preset frequency, wherein the preset frequency is the product of the current frequency of the compressor and a preset proportion.

Optionally, the method for controlling freezing prevention of an air conditioner of the present invention further comprises: after the air conditioner executes the anti-freezing operation and lasts for a set time, acquiring a second working current of an internal fan, a second air inlet temperature and a second air outlet temperature of an indoor unit when the air conditioner runs in a current working mode; if the second working current is equal to the preset reference current and the temperature difference value between the second inlet air temperature and the second outlet air temperature is smaller than a preset second temperature difference threshold value, controlling the air conditioner to exit the anti-freezing mode; the second temperature difference threshold is less than the first temperature difference threshold.

Optionally, after responding to the trigger signal, before obtaining a first working current of the inner fan, a first air inlet temperature of the indoor unit, a first air outlet temperature, and an inner coil temperature when the air conditioner operates in the current working mode, the control method further includes: and controlling to switch the air deflector of the indoor unit of the air conditioner to the maximum air outlet angle.

Here, for the specific process of the air conditioner executing the above flow, reference may be made to the technical content disclosed in the corresponding part of the embodiment shown in fig. 3, and details are not described herein.

Fig. 5 is a control method for preventing freezing of an air conditioner according to the present invention, shown in accordance with still another exemplary embodiment.

As shown in fig. 5, the present invention further provides another control method for preventing freezing of an air conditioner, which can also be used to solve the problem that the air-out efficiency and the heat exchange efficiency are affected by freezing of a heat exchange tube of an indoor heat exchanger caused by a low-temperature refrigerant when the air conditioner operates in a refrigeration or dehumidification mode; specifically, the method mainly comprises the following steps:

s501, responding to a received trigger signal for detecting whether the air conditioner has a freezing problem, and acquiring a first working current of an inner fan, a first air inlet temperature of an indoor unit, a first air outlet temperature and an inner coil temperature when the air conditioner runs in a current working mode;

in this embodiment, the specific execution process of step S501 may refer to step S401 in the foregoing, which is not described herein again;

s502, determining whether the air conditioner has a freezing problem or not according to the first working current of the inner fan, the first air inlet temperature of the indoor unit, the first air outlet temperature, the temperature of the inner coil and a preset freezing temperature threshold value.

Optionally, in step S502, it is determined whether the air conditioner has a freezing problem according to a first working current of the inner fan, a first air inlet temperature of the indoor unit, and a first air outlet temperature, and the specific process may include: and if the ratio of the first working current of the inner fan to the preset reference current is smaller than a preset ratio threshold value, the temperature difference value between the first air inlet temperature and the first air outlet temperature is larger than a preset first temperature difference threshold value, and the temperature difference value between the temperature of the inner coil pipe and the preset freezing temperature threshold value is larger than a preset second temperature difference threshold value, determining that the indoor heat exchanger of the air conditioner has the freezing problem.

The freezing temperature threshold and the second temperature difference threshold are both threshold parameters prestored in the air conditioner, and optionally, the value of the freezing temperature threshold is 0 ℃, and the value of the second temperature difference threshold is 5 ℃.

The air conditioner and the anti-freezing control method thereof can judge the freezing condition of the air conditioner according to the working current, the air inlet temperature, the air outlet temperature, the temperature of the inner coil and the freezing temperature threshold of the inner fan of the air conditioner, and can control the air conditioner to perform anti-freezing protection on the indoor heat exchanger in time when the freezing problem of the air conditioner can be judged; the control method for preventing the air conditioner from freezing can enable the air conditioner to trigger self anti-freezing protection more timely and sensitively, and ensures the safe and stable operation of the air conditioner.

Optionally, the method for controlling freezing prevention of an air conditioner of the present invention further comprises: in response to determining that the indoor heat exchanger of the air conditioner has a freezing problem, controlling the air conditioner to switch to an anti-freezing mode; wherein the freeze prevention mode includes: controlling to reduce the current frequency of the compressor to a preset frequency, wherein the preset frequency is the product of the current frequency of the compressor and a preset proportion; alternatively, the opening degree of the throttle device is increased.

Optionally, the method for controlling freezing prevention of an air conditioner of the present invention further comprises: after the air conditioner executes the anti-freezing operation and lasts for a set time, acquiring a second working current of an internal fan, a second air inlet temperature and a second air outlet temperature of an indoor unit when the air conditioner runs in a current working mode; if the second working current is equal to the preset reference current and the temperature difference value between the second inlet air temperature and the second outlet air temperature is smaller than a preset third temperature difference threshold value, controlling the air conditioner to exit the anti-freezing mode; the third temperature difference threshold is less than the first temperature difference threshold.

Fig. 6 is a control method for preventing freezing of an air conditioner according to the present invention, which is shown in accordance with still another exemplary embodiment.

As shown in fig. 6, the present invention further provides another control method for preventing freezing of an air conditioner, which can also be used to solve the problem that the air-out efficiency and the heat exchange efficiency are affected by freezing of a heat exchange tube of an indoor heat exchanger caused by a low-temperature refrigerant when the air conditioner operates in a refrigeration or dehumidification mode; specifically, the method mainly comprises the following steps:

s601, responding to a received trigger signal for detecting whether the air conditioner has a freezing problem, and acquiring a first working current of an inner fan, a first air inlet temperature of an indoor unit, a first air outlet temperature and an inner coil temperature when the air conditioner runs in a current working mode;

in this embodiment, the specific execution process of step S601 may refer to step S401 in the foregoing, which is not described herein again;

s602, determining whether the air conditioner has a freezing problem or not according to the first working current of the inner fan, a preset ratio threshold value, the first air inlet temperature of the indoor unit, the first air outlet temperature and the temperature of the inner coil.

Optionally, in step S602, it is determined whether the air conditioner has a freezing problem according to a first working current of the inner fan, a first air inlet temperature of the indoor unit, and a first air outlet temperature, where the determining includes: if the ratio of the first working current of the inner fan to the preset reference current is larger than a preset ratio threshold value, the temperature difference value between the first air inlet temperature and the first air outlet temperature is larger than a preset first temperature difference threshold value, and the temperature of the inner coil is smaller than a preset freezing temperature threshold value, the indoor heat exchanger of the air conditioner is determined to have the freezing problem.

Here, the specific execution flow when the temperature difference between the first inlet air temperature and the first outlet air temperature is greater than the preset first temperature difference threshold, and the temperature of the inner coil is less than the preset freezing temperature threshold may refer to the technical content of the corresponding part of the embodiment shown in fig. 4, and is not described herein again.

Optionally, the value of the ratio threshold is 1.2;

for example, the reference current matched with a certain inner fan gear is I b, the first operating current of the inner fan acquired in step S301 is I S, and when I S/I b > 1.2, it may be determined that a judgment sub-condition related to the current parameter when performing the air conditioner freezing judgment is satisfied; when I s/I b is less than or equal to 1.2, it is determined that the judgment sub-condition concerning the current parameter at the time of the air conditioner freezing judgment is not satisfied.

Alternatively, the anti-freeze mode may increase the opening degree of the throttle device in addition to reducing the frequency of the compressor.

Fig. 7 is a control method for preventing freezing of an air conditioner according to the present invention, shown in accordance with still another exemplary embodiment.

As shown in fig. 7, the present invention further provides another control method for preventing freezing of an air conditioner, which can also be used to solve the problem that the air-out efficiency and the heat exchange efficiency are affected by freezing of a heat exchange tube of an indoor heat exchanger caused by a low-temperature refrigerant when the air conditioner operates in a refrigeration or dehumidification mode; specifically, the method mainly comprises the following steps:

s701, acquiring the current working current of an internal fan when the air conditioner operates in the current working mode in response to receiving a trigger signal for detecting whether the air conditioner has a freezing problem;

in this embodiment, the specific obtaining process of the current working current may refer to the step S401 in the foregoing, which is not described herein again.

S702, determining whether the air conditioner has a freezing problem or not according to the current working current of the inner fan;

optionally, in step S702, it is determined whether the air conditioner has a freezing problem according to the current working current of the inner fan, and the specific process may include: if the current working current of the inner fan is smaller than a preset first current threshold value, determining that the air conditioner does not have the freezing problem; if the current working current of the inner fan is larger than or equal to a preset first current threshold value, determining that the air conditioner has a freezing problem;

here, the first current threshold is a preset threshold parameter of the air conditioner, and is used for representing a critical current of the corresponding inner fan when the air conditioner has a freezing problem.

And S703, when the freezing problem of the air conditioner is determined, determining to start the anti-freezing operation corresponding to the anti-freezing mode according to the current working current.

In response to determining that there is a freezing problem with the air conditioner, switching the air conditioner to an anti-freeze mode; therefore, the step S703 of determining, according to the current operating current, that the anti-freeze operation corresponding to the anti-freeze mode is enabled includes:

if the current working current of the inner fan is greater than or equal to a preset first current threshold and less than a preset second current threshold, the anti-freezing operation corresponding to the anti-freezing mode comprises the steps of increasing the opening degree of the throttling device and reducing the current frequency of the compressor to a first preset frequency; the first preset frequency is the product of the current frequency of the compressor and a first preset proportion, and the second current threshold is used for representing that the indoor heat exchanger of the air conditioner achieves a first icing degree;

if the current working current of the inner fan is greater than or equal to a preset second current threshold and less than or equal to a preset third current threshold, the anti-freezing operation corresponding to the anti-freezing mode comprises reducing the current frequency of the compressor to a second preset frequency; the second preset frequency is the product of the current frequency of the compressor and a second preset proportion, and the third current threshold is used for representing that the indoor heat exchanger of the air conditioner reaches a second icing degree; the second preset proportion is smaller than the first preset proportion, and the second icing degree is larger than the first icing degree;

and if the current working current of the inner fan is greater than a preset third current threshold value, the anti-freezing operation corresponding to the anti-freezing mode comprises controlling the air conditioner to stop.

Optionally, the method for controlling freezing prevention of an air conditioner of the present invention further comprises: after the air conditioner executes the anti-freezing operation and lasts for a set time, acquiring the working current of an internal fan when the air conditioner runs in the current working mode; re-determining whether the air conditioner has a freezing problem or not according to the working current of the inner fan; and if the air conditioner is determined not to have the freezing problem, controlling the air conditioner to exit the anti-freezing mode.

Here, the above-mentioned process for re-determining the freezing problem of the air conditioner according to the operating current of the internal fan may refer to the foregoing steps S701 to S702, which are not described herein again.

Optionally, after responding to the trigger signal, before obtaining the current working current of the internal fan when the air conditioner operates in the current working mode, the control method further includes: and controlling to switch the air deflector of the indoor unit of the air conditioner to the maximum air outlet angle. Here, for the specific process of the air conditioner executing the above flow, reference may be made to the technical content disclosed in the corresponding part of the embodiment shown in fig. 3, and details are not described herein.

Fig. 8 is a control method for preventing freezing of an air conditioner according to the present invention, which is shown in accordance with still another exemplary embodiment.

As shown in fig. 8, the present invention further provides another control method for preventing freezing of an air conditioner, which can also be used to solve the problem that the air-out efficiency and the heat exchange efficiency are affected by freezing of a heat exchange tube of an indoor heat exchanger caused by a low-temperature refrigerant when the air conditioner operates in a refrigeration or dehumidification mode; specifically, the method mainly comprises the following steps:

s801, responding to a received trigger signal for detecting whether the air conditioner has a freezing problem, and acquiring the current working current, the temperature of an inner coil, the air inlet temperature and the air outlet temperature of an inner fan when the air conditioner runs in the current working mode;

in this embodiment, the specific execution flow of step S801 may refer to step S401 in the foregoing, which is not described herein again.

S802, determining whether the air conditioner has a freezing problem or not according to the current working current of the inner fan, the temperature of the inner coil, the air inlet temperature and the air outlet temperature;

optionally, in step S802, it is determined whether the air conditioner has a freezing problem according to the current working current of the inner fan, the temperature of the inner coil, the temperature of the inlet air, and the temperature of the outlet air, and the specific process includes: if the current working current of the inner fan is smaller than a preset first current threshold value, the temperature of the inner coil is larger than a preset freezing temperature threshold value, and the temperature difference value between the inlet air temperature and the outlet air temperature is smaller than a preset temperature difference threshold value, determining that the air conditioner does not have the freezing problem; otherwise, determining that the air conditioner has a freezing problem;

here, the first current threshold, the freezing temperature threshold, and the temperature difference threshold are threshold parameters preset by the air conditioner. The first current threshold is used for representing the critical current of the corresponding inner fan when the air conditioner has a freezing problem; optionally, the value of the freezing temperature threshold is 0 ℃; the value of the temperature difference threshold is 5 ℃.

And S803, when the freezing problem of the air conditioner is determined, the anti-freezing operation corresponding to the anti-freezing mode is determined to be started according to the current working current and the temperature of the inner coil.

In response to determining that there is a freezing problem with the air conditioner, switching the air conditioner to an anti-freeze mode; therefore, in step S803, the anti-freezing operation corresponding to the anti-freezing mode is determined to be enabled according to the current working current and the temperature of the internal coil, and includes:

and if the current working current of the inner fan is greater than a preset third current threshold value and the temperature of the inner coil is less than or equal to a preset freezing temperature threshold value, the anti-freezing operation corresponding to the anti-freezing mode comprises controlling the air conditioner to stop. Or, the anti-freezing mode of the air conditioner switching can also comprise controlling the air conditioner to be switched to the heating mode for operation.

Here, for the specific execution flow of switching the air conditioner to the heating mode and the load protection operation when the air conditioner operates in the heating mode, reference may be made to the technical contents disclosed in the foregoing embodiments, and details are not described herein.

Optionally, the method for controlling freezing prevention of an air conditioner of the present invention further comprises: after the air conditioner executes the anti-freezing operation and lasts for a set time, acquiring the working current of an internal fan when the air conditioner runs in the current working mode; re-determining whether the air conditioner has a freezing problem or not according to the working current of the inner fan, the temperature of the inner coil, the air inlet temperature and the air outlet temperature;

here, the above-mentioned process for re-determining the freezing problem of the air conditioner according to the operating current of the inner fan may refer to step S803 in the foregoing, which is not described herein again.

Optionally, after responding to the trigger signal, before obtaining the current working current, the temperature of the inner coil, the temperature of the inlet air and the temperature of the outlet air of the inner fan when the air conditioner operates in the current working mode, the control method further includes: and controlling to switch the air deflector of the indoor unit of the air conditioner to the maximum air outlet angle. Here, for the specific process of the air conditioner executing the above flow, reference may be made to the technical content disclosed in the corresponding part of the embodiment shown in fig. 3, and details are not described herein.

Fig. 9 is a control method for preventing freezing of an air conditioner according to the present invention, shown in accordance with still another exemplary embodiment.

As shown in fig. 9, the present invention further provides another control method for preventing freezing of an air conditioner, which can also be used to solve the problem that the air-out efficiency and the heat exchange efficiency are affected by freezing of a heat exchange tube of an indoor heat exchanger caused by a low-temperature refrigerant when the air conditioner operates in a refrigeration or dehumidification mode; specifically, the method mainly comprises the following steps:

s901, acquiring the current working current, the temperature of an outer coil, the air inlet temperature and the air outlet temperature of an inner fan when the air conditioner runs in the current working mode in response to receiving a trigger signal for detecting whether the air conditioner has a freezing problem;

in this embodiment, in step S901, in addition to the current working current, the inlet air temperature and the outlet air temperature detected in step S301, another temperature sensor is further provided in the outdoor heat exchanger of the outdoor unit, and the temperature sensor can be used to sense the real-time temperature of the external coil of the outdoor heat exchanger, so that in step S901, the real-time temperature of the external coil detected by the temperature sensor is taken as the external coil temperature;

s902, determining whether the air conditioner has a freezing problem or not according to the current working current of the inner fan, the temperature of the outer coil, the air inlet temperature and the air outlet temperature;

optionally, in step S902, it is determined whether the air conditioner has a freezing problem according to the current working current of the inner fan, the temperature of the outer coil, the temperature of the inlet air, and the temperature of the outlet air, and the determining may specifically include: if the current working current of the inner fan is smaller than a preset first current threshold value, the temperature of the outer coil is larger than a preset freezing temperature threshold value, and the temperature difference value between the inlet air temperature and the outlet air temperature is smaller than a preset temperature difference threshold value, determining that the air conditioner does not have the freezing problem; otherwise, determining that the air conditioner has a freezing problem;

here, the first current threshold, the freezing temperature threshold and the temperature difference threshold are preset threshold parameters of the air conditioner; the first current threshold is used for representing the critical current of the corresponding inner fan when the air conditioner has a freezing problem; optionally, the freezing temperature threshold value is-2 ℃; the value of the temperature difference threshold is 5 ℃.

And S903, when the freezing problem of the air conditioner is determined, the anti-freezing operation corresponding to the anti-freezing mode is determined to be started according to the current working current and the temperature of the external coil.

In response to determining that there is a freezing problem with the air conditioner, switching the air conditioner to an anti-freeze mode; therefore, in step S903, the anti-freezing operation corresponding to the anti-freezing mode is determined to be activated according to the current working current and the temperature of the external coil, and includes:

if the current working current of the inner fan is greater than or equal to a preset first current threshold and less than a preset second current threshold, and the temperature of the outer coil is less than or equal to a preset freezing temperature threshold, the anti-freezing operation corresponding to the anti-freezing mode comprises the steps of increasing the opening degree of the throttling device and reducing the current frequency of the compressor to a first preset frequency; the first preset frequency is the product of the current frequency of the compressor and a first preset proportion, and the second current threshold is used for representing that the indoor heat exchanger of the air conditioner achieves a first icing degree;

if the current working current of the inner fan is greater than or equal to a preset second current threshold value and less than or equal to a preset third current threshold value, and the temperature of the outer coil is less than or equal to a preset freezing temperature threshold value, the anti-freezing operation corresponding to the anti-freezing mode comprises the step of reducing the current frequency of the compressor to a second preset frequency; the second preset frequency is the product of the current frequency of the compressor and a second preset proportion, and the third current threshold is used for representing that the indoor heat exchanger of the air conditioner reaches a second icing degree; the second preset proportion is smaller than the first preset proportion, and the second icing degree is larger than the first icing degree;

and if the current working current of the inner fan is greater than a preset third current threshold value and the temperature of the outer coil is less than or equal to a preset freezing temperature threshold value, the anti-freezing operation corresponding to the anti-freezing mode comprises controlling the air conditioner to stop.

Optionally, the method for controlling freezing prevention of an air conditioner of the present invention further comprises: after the air conditioner executes the anti-freezing operation and lasts for a set time, acquiring the working current of an internal fan when the air conditioner runs in the current working mode; re-determining whether the air conditioner has a freezing problem or not according to the working current of the inner fan, the temperature of the outer coil, the air inlet temperature and the air outlet temperature;

here, the aforementioned step S902 may be referred to according to the working current of the inner fan, the temperature of the outer coil, the temperature of the inlet air, and the temperature of the outlet air, and will not be described herein again.

Optionally, after responding to the trigger signal, before obtaining the current working current of the internal fan, the temperature of the external coil, the temperature of the intake air, and the temperature of the outtake air when the air conditioner operates in the current working mode, the control method further includes: and controlling to switch the air deflector of the indoor unit of the air conditioner to the maximum air outlet angle. Here, for the specific process of the air conditioner executing the above flow, reference may be made to the technical content disclosed in the corresponding part of the embodiment shown in fig. 3, and details are not described herein.

In an alternative embodiment, the present invention further provides an air conditioner capable of performing the control flow disclosed in the embodiment of fig. 1 above.

The air conditioner also comprises an air conditioner body and a controller, wherein the controller is used for:

acquiring the air inlet temperature, the air outlet temperature and the temperature of an inner coil of an indoor unit when the air conditioner operates in a refrigeration mode;

and determining that the indoor heat exchanger of the air conditioner has a freezing problem in response to the fact that the temperature difference between the inlet air temperature and the outlet air temperature is larger than a preset difference threshold value and the temperature of the inner coil is smaller than a preset temperature threshold value.

Optionally, the controller is further configured to:

and controlling the air conditioner to switch to an anti-freezing mode in response to determining that the indoor heat exchanger of the air conditioner has a freezing problem.

Optionally, the freeze prevention mode includes:

sequentially executing a plurality of periodic flows defining anti-freezing operations, the periodic flows sequentially including a first periodic flow defining one or more anti-freezing operations to increase an opening degree of a throttle device, a second periodic flow defining one or more anti-freezing operations to decrease a frequency of a compressor, and a third periodic flow defining one or more anti-freezing operations to control a shutdown of an air conditioner; re-determining whether the indoor heat exchanger of the air conditioner has a freezing problem after the execution of each cycle flow is completed; and if the newly determined indoor heat exchanger of the air conditioner has no freezing problem, exiting the anti-freezing mode.

Optionally, the controller is further configured to:

and acquiring the attenuation speed of the temperature of the inner coil and the temperature of the inner coil, and matching according to a preset incidence relation to obtain the frequency reduction amplitude of the compressor of the corresponding second period process, wherein the incidence relation is used for representing the corresponding relation between the attenuation speed of the temperature of the inner coil, the temperature of the inner coil and the frequency reduction amplitude.

Optionally, the decay rate of the temperature of the inner coil in the correlation is positively correlated to the down-conversion amplitude.

The specific manner of executing the above process by the air conditioner control may refer to the foregoing embodiments, which are not described herein again.

In an alternative embodiment, the present invention further provides an air conditioner capable of performing the control flow disclosed in the embodiment of fig. 2 above.

The air conditioner includes air conditioner organism and controller, and the controller is used for:

and determining that the indoor heat exchanger of the air conditioner has a freezing problem in response to the fact that the temperature difference between the inlet air temperature and the outlet air temperature is larger than a preset difference threshold, the temperature change rate of the temperature of the inner coil is larger than a set rate threshold and the temperature of the inner coil is smaller than a preset temperature threshold.

Optionally, the controller is further configured to:

Optionally, the freeze prevention mode includes:

Optionally, the controller is further configured to:

In an alternative embodiment, the present invention further provides an air conditioner capable of performing the control flow disclosed in the embodiment of fig. 3 above.

responding to a received trigger signal for detecting whether the air conditioner has a freezing problem, and acquiring a first working current of an inner fan, a first air inlet temperature and a first air outlet temperature of an indoor unit when the air conditioner operates in a current working mode;

and determining whether the air conditioner has a freezing problem or not according to the first working current of the inner fan, the first air inlet temperature and the first air outlet temperature of the indoor unit.

Optionally, the controller is specifically configured to:

and if the ratio of the first working current of the inner fan to the preset reference current is smaller than a preset ratio threshold value, and the temperature difference value between the first air inlet temperature and the first air outlet temperature is larger than a preset first temperature difference threshold value, determining that the indoor heat exchanger of the air conditioner has the freezing problem.

Optionally, the controller is further configured to:

in response to determining that the indoor heat exchanger of the air conditioner has a freezing problem, controlling the air conditioner to switch to an anti-freezing mode;

Optionally, the controller is further configured to:

after the air conditioner executes the anti-freezing operation and lasts for a set time, acquiring a second working current of an internal fan, a second air inlet temperature and a second air outlet temperature of an indoor unit when the air conditioner runs in a current working mode;

if the second working current is equal to the preset reference current and the temperature difference value between the second inlet air temperature and the second outlet air temperature is smaller than a preset second temperature difference threshold value, controlling the air conditioner to exit the anti-freezing mode;

the second temperature difference threshold is less than the first temperature difference threshold.

Optionally, the controller is further configured to control to switch the air deflector of the indoor unit of the air conditioner to the maximum air outlet angle after responding to the trigger signal and before acquiring the first working current of the inner fan, the first air inlet temperature of the indoor unit, and the first air outlet temperature when the air conditioner operates in the current working mode.

In an alternative embodiment, the present invention further provides an air conditioner capable of executing the control flow disclosed in the embodiment of fig. 4 above.

responding to a received trigger signal for detecting whether the air conditioner has a freezing problem, and acquiring a first working current of an inner fan, a first air inlet temperature of an indoor unit, a first air outlet temperature and an inner coil temperature when the air conditioner operates in a current working mode;

and determining whether the air conditioner has a freezing problem or not according to the first working current of the inner fan, the first air inlet temperature, the first air outlet temperature and the temperature of the inner coil pipe of the indoor unit.

Optionally, the controller is specifically configured to:

if the ratio of the first working current of the inner fan to the preset reference current is smaller than a preset ratio threshold value, the temperature difference value between the first air inlet temperature and the first air outlet temperature is larger than a preset first temperature difference threshold value, and the temperature of the inner coil is smaller than a preset freezing temperature threshold value, the indoor heat exchanger of the air conditioner is determined to have the freezing problem.

Optionally, the controller is further configured to:

Optionally, the controller is further configured to control to switch the air deflector of the indoor unit of the air conditioner to the maximum air outlet angle after responding to the trigger signal and before acquiring the first working current of the inner fan, the first air inlet temperature, the first air outlet temperature, and the inner coil temperature when the air conditioner operates in the current working mode.

In an alternative embodiment, the present invention further provides an air conditioner capable of executing the control flow disclosed in the embodiment of fig. 5 above.

and determining whether the air conditioner has a freezing problem or not according to the first working current of the inner fan, the first air inlet temperature, the first air outlet temperature, the temperature of the inner coil pipe and a preset freezing temperature threshold value of the indoor unit.

Optionally, the controller is specifically configured to:

and if the ratio of the first working current of the inner fan to the preset reference current is smaller than a preset ratio threshold value, the temperature difference value between the first air inlet temperature and the first air outlet temperature is larger than a preset first temperature difference threshold value, and the temperature difference value between the temperature of the inner coil pipe and the preset freezing temperature threshold value is larger than a preset second temperature difference threshold value, determining that the indoor heat exchanger of the air conditioner has the freezing problem.

Optionally, the controller is further configured to:

wherein the freeze prevention mode includes: controlling to reduce the current frequency of the compressor to a preset frequency, wherein the preset frequency is the product of the current frequency of the compressor and a preset proportion; alternatively, the opening degree of the throttle device is increased.

Optionally, the controller is further configured to:

if the second working current is equal to the preset reference current and the temperature difference value between the second inlet air temperature and the second outlet air temperature is smaller than a preset third temperature difference threshold value, controlling the air conditioner to exit the anti-freezing mode;

the third temperature difference threshold is less than the first temperature difference threshold.

Optionally, the controller is further configured to: after the trigger signal is responded, before the first working current of the inner fan, the first air inlet temperature of the indoor unit, the first air outlet temperature and the inner coil temperature of the air conditioner in the current working mode are obtained, the air deflector of the indoor unit of the air conditioner is controlled to be switched to the maximum air outlet angle.

In an alternative embodiment, the present invention further provides an air conditioner capable of performing the control flow disclosed in the embodiment of fig. 6 above.

and determining whether the air conditioner has a freezing problem or not according to the first working current of the inner fan, a preset ratio threshold value, the first air inlet temperature of the indoor unit, the first air outlet temperature and the temperature of the inner coil.

Optionally, the controller is specifically configured to:

if the ratio of the first working current of the inner fan to the preset reference current is larger than a preset ratio threshold value, the temperature difference value between the first air inlet temperature and the first air outlet temperature is larger than a preset first temperature difference threshold value, and the temperature of the inner coil is smaller than a preset freezing temperature threshold value, the indoor heat exchanger of the air conditioner is determined to have the freezing problem.

Optionally, the controller is further configured to:

In an alternative embodiment, the present invention further provides an air conditioner capable of performing the control flow disclosed in the embodiment of fig. 7 above.

acquiring the current working current of an inner fan when the air conditioner operates in the current working mode in response to receiving a trigger signal for detecting whether the air conditioner has a freezing problem;

determining whether the air conditioner has a freezing problem or not according to the current working current of the inner fan; and when the freezing problem of the air conditioner is determined, the anti-freezing operation corresponding to the anti-freezing mode is determined to be started according to the current working current.

Optionally, the controller is specifically configured to:

if the current working current of the inner fan is smaller than a preset first current threshold value, determining that the air conditioner does not have the freezing problem;

if the current working current of the inner fan is larger than or equal to a preset first current threshold value, determining that the air conditioner has a freezing problem;

Optionally, the controller is further configured to: in response to determining that there is a freezing problem with the air conditioner, switching the air conditioner to an anti-freeze mode;

the controller is specifically configured to:

Optionally, the controller is further configured to:

re-determining whether the air conditioner has a freezing problem or not according to the working current of the inner fan;

Optionally, the controller is further configured to: and after responding to the trigger signal, controlling to switch an air deflector of an indoor unit of the air conditioner to the maximum air outlet angle before acquiring the current working current of the inner fan when the air conditioner operates in the current working mode.

In an alternative embodiment, the present invention further provides an air conditioner capable of executing the control flow disclosed in the embodiment of fig. 8 above.

Optionally, the controller is specifically configured to:

Optionally, the controller is further configured to switch the air conditioner to an anti-freezing mode in response to determining that the air conditioner has a freezing problem;

the controller is specifically configured to:

Optionally, the controller is further configured to:

Optionally, the controller is further configured to control to switch an air deflector of an indoor unit of the air conditioner to a maximum air outlet angle after responding to the trigger signal and before acquiring a current working current, an inner coil temperature, an air inlet temperature, and an air outlet temperature of the inner fan when the air conditioner operates in the current working mode.

In an alternative embodiment, the present invention further provides an air conditioner capable of executing the control flow disclosed in the embodiment of fig. 9 above.

acquiring the current working current, the temperature of an outer coil pipe, the air inlet temperature and the air outlet temperature of an inner fan when the air conditioner operates in the current working mode in response to receiving a trigger signal for detecting whether the air conditioner has a freezing problem;

determining whether the air conditioner has a freezing problem or not according to the current working current of the inner fan, the temperature of the outer coil pipe, the air inlet temperature and the air outlet temperature; and when the freezing problem of the air conditioner is determined, the anti-freezing operation corresponding to the anti-freezing mode is determined to be started according to the current working current and the temperature of the external coil.

Optionally, the controller is specifically configured to:

if the current working current of the inner fan is smaller than a preset first current threshold value, the temperature of the outer coil is larger than a preset freezing temperature threshold value, and the temperature difference value between the inlet air temperature and the outlet air temperature is smaller than a preset temperature difference threshold value, determining that the air conditioner does not have the freezing problem; otherwise, determining that the air conditioner has a freezing problem;

the controller is specifically configured to:

Optionally, the controller is further configured to:

re-determining whether the air conditioner has a freezing problem or not according to the working current of the inner fan, the temperature of the outer coil, the air inlet temperature and the air outlet temperature;

Optionally, the controller is further configured to: and after responding to the trigger signal, controlling to switch an air deflector of an indoor unit of the air conditioner to a maximum air outlet angle before acquiring the current working current of the inner fan, the temperature of the outer coil pipe, the air inlet temperature and the air outlet temperature when the air conditioner operates in the current working mode.

It is to be understood that the present invention is not limited to the procedures and structures described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims

1. A control method for preventing freezing of an air conditioner is characterized by comprising the following steps:

the method comprises the steps that in response to the fact that a trigger signal for detecting whether the air conditioner has a freezing problem or not is received, the current working current, the temperature of an inner coil pipe, the air inlet temperature and the air outlet temperature of an inner fan when the air conditioner runs in a current working mode are obtained;

2. The control method according to claim 1, wherein the determining whether the air conditioner has a freezing problem according to the current working current of the inner fan, the temperature of the inner coil, the temperature of the inlet air and the temperature of the outlet air comprises:

if the current working current of the inner fan is smaller than a preset first current threshold value, the temperature of the inner coil is larger than a preset freezing temperature threshold value, and the temperature difference value between the inlet air temperature and the outlet air temperature is smaller than a preset temperature difference threshold value, determining that the air conditioner does not have a freezing problem; otherwise, determining that the air conditioner has a freezing problem;

3. The control method according to claim 2, wherein in response to determining that there is a freezing problem with the air conditioner, the air conditioner switches to an anti-freeze mode;

the determining of the anti-freezing operation corresponding to the anti-freezing mode according to the current working current and the temperature of the inner coil comprises the following steps:

if the current working current of the inner fan is greater than or equal to the preset first current threshold and less than the preset second current threshold, and the temperature of the inner coil is less than or equal to the preset freezing temperature threshold, the anti-freezing operation corresponding to the anti-freezing mode comprises increasing the opening degree of the throttling device and reducing the current frequency of the compressor to a first preset frequency; the first preset frequency is the product of the current frequency of the compressor and a first preset proportion, and the second current threshold is used for representing that the indoor heat exchanger of the air conditioner achieves a first icing degree;

and if the current working current of the inner fan is greater than the preset third current threshold value and the temperature of the inner coil is less than or equal to the preset freezing temperature threshold value, the anti-freezing operation corresponding to the anti-freezing mode comprises controlling the air conditioner to stop.

4. The control method according to claim 1, characterized by further comprising:

re-determining whether the air conditioner has a freezing problem or not according to the working current of the inner fan, the temperature of the inner coil, the temperature of inlet air and the temperature of outlet air;

5. The control method of claim 1, wherein after responding to the trigger signal, before obtaining a current operating current, an inner coil temperature, an inlet air temperature and an outlet air temperature of an inner fan in a current operating mode of the air conditioner, the control method further comprises:

6. An air conditioner, characterized in that, the air conditioner includes air conditioner organism and controller, the controller is used for:

7. The air conditioner of claim 6, wherein the controller is specifically configured to:

8. The air conditioner of claim 7, wherein the controller is further configured to switch to an anti-freeze mode in response to determining that the air conditioner has a freeze problem;

the controller is specifically configured to:

9. The air conditioner of claim 6, wherein the controller is further configured to:

10. The air conditioner of claim 6, wherein the controller is further configured to control the air deflector of the indoor unit of the air conditioner to be switched to the maximum air outlet angle after the trigger signal is responded and before the current working current, the temperature of the inner coil, the air inlet temperature, and the air outlet temperature of the inner fan in the current working mode of the air conditioner are obtained.