WO2024109148A1

WO2024109148A1 - Air conditioner and control method therefor

Info

Publication number: WO2024109148A1
Application number: PCT/CN2023/110308
Authority: WO
Inventors: 赵江龙; 黄罡; 孙升华
Original assignee: 青岛海尔空调器有限总公司; 青岛海尔空调电子有限公司; 海尔智家股份有限公司
Priority date: 2022-11-25
Filing date: 2023-07-31
Publication date: 2024-05-30
Also published as: CN115899994A

Abstract

An air conditioner and a control method therefor. The control method for the air conditioner comprises: acquiring the surface temperature Tr of an evaporator of the air conditioner; if the surface temperature Tr meets a first anti-freezing mode starting condition, starting a first anti-freezing mode, regulation and control items of the first anti-freezing mode comprising one or more of increasing the air outlet area of an indoor air outlet of the air conditioner, increasing the rotating speed of an indoor fan of the air conditioner, decreasing the rotating speed of an outdoor fan of the air conditioner, and increasing the opening degree of an expansion valve of the air conditioner; and once the first anti-freezing mode reaches a regulation goal, starting a second anti-freezing mode. The present invention relieves temperature fluctuation caused when air conditioners operate a freezing protection mechanism.

Description

Air conditioner and control method thereof

Technical Field

The present invention relates to the technical field of air conditioning, and in particular to an air conditioner and a control method thereof.

Background technique

When the air conditioner is in cooling operation, the surface temperature of the evaporator is often too low due to various factors such as low inlet air temperature and insufficient refrigerant circulation, until ice forms, which is called evaporator freezing. Evaporator freezing will lead to adverse consequences such as water leakage, water blowing, and ice blowing.

To solve the problem of evaporator freezing, the air conditioner usually reduces the frequency of the compressor until it stops during cooling operation. However, the frequency reduction, shutdown, startup, and frequency increase during the operation of the air conditioner will cause large temperature fluctuations, affecting the user's cooling and heating experience.

Summary of the invention

The purpose of the present invention is to solve at least one of the above-mentioned defects in the prior art.

The purpose of the present invention is to alleviate the temperature fluctuation problem caused by the air conditioner when the freeze protection mechanism is running.

In one aspect, the present invention provides a method for controlling an air conditioner, comprising:

Obtaining the evaporator surface temperature Tr of the air conditioner;

If the surface temperature Tr meets the first antifreeze mode activation condition, the first antifreeze mode is activated; the control items of the first antifreeze mode include increasing the air outlet area of the indoor air outlet of the air conditioner, increasing the indoor fan speed of the air conditioner, decreasing the outdoor fan speed of the air conditioner, and increasing the opening of the expansion valve of the air conditioner.

After the first antifreeze mode reaches the adjustment target, the second antifreeze mode is activated.

Optionally, the adjustment target is: to make the surface temperature Tr no longer meet the first antifreeze mode activation condition, or the control parameter of the control item has been adjusted to a limit value.

Optionally, the control strategy of at least one of the control items is: adjusting the corresponding control parameters step by step until the control target is achieved.

Optionally, the control items of the first antifreeze mode include increasing the air outlet area of the indoor air outlet of the air conditioner, increasing the speed of the indoor fan of the air conditioner, decreasing the speed of the outdoor fan of the air conditioner, and increasing the opening of the expansion valve of the air conditioner;

In the first antifreeze mode, each of the control items is operated in a preset order; and

If the control parameter of the control item in the previous order is adjusted to below the limit value, so that the surface temperature Tr no longer meets the first antifreeze mode activation condition, it is determined that the control target is achieved, otherwise the next control item is entered;

The last control item in the sequence makes the surface temperature Tr no longer meet the first antifreeze mode activation condition, or the control parameter is adjusted to a limit value, and it is determined that the control target is achieved.

Optionally, the execution order of the control items of the first antifreeze mode is from front to back: increasing the air outlet area of the indoor air outlet of the air conditioner, increasing the indoor fan speed of the air conditioner, reducing the outdoor fan speed of the air conditioner, and increasing the opening of the expansion valve of the air conditioner.

In the first antifreeze mode, various control items are executed simultaneously;

When the surface temperature Tr no longer satisfies the first antifreeze mode activation condition, or the control parameters of each of the control items have been adjusted to the limit value, it is determined that the control target is achieved.

Optionally, the surface temperature Tr satisfies a first antifreeze mode activation condition including: Tr≤T1, where T1 is a preset freezing protection temperature.

Optionally, the second antifreeze mode includes: controlling the compressor of the air conditioner to reduce frequency until it stops.

After the first anti-freeze mode achieves the adjustment target, the air conditioner is controlled to send a freezing reminder to the user to remind the user to clean the filter of the air conditioner and check the amount of refrigerant.

On the other hand, the present invention also provides an air conditioner, which includes a controller, the controller includes a processor and a memory, the memory stores a computer program, and the computer program is used to implement the control method described in any one of the above items when executed by the processor.

In the control method of the present invention, the antifreeze program includes a first antifreeze mode and a second antifreeze mode. The control items of the first antifreeze mode include increasing the air outlet area of the indoor air outlet of the air conditioner, increasing the indoor fan speed of the air conditioner, reducing the outdoor fan speed of the air conditioner, and increasing the expansion valve opening of the air conditioner. The second antifreeze mode includes controlling the compressor of the air conditioner to reduce the frequency until it stops. The first antifreeze mode is run first, and when its adjustment target is achieved, the second antifreeze mode is started. After double adjustment, the antifreeze target is gradually achieved, and the time of frequency reduction and shutdown is shortened, avoiding large fluctuations in indoor temperature caused by directly reducing the frequency or shutting down the compressor.

Furthermore, in the control method of the present invention, a plurality of control items are designed for the first antifreeze mode. In specific control, each control item is operated in a preset order. Before the parameter is adjusted to the limit value, the surface temperature Tr no longer meets the first antifreeze mode activation condition, and it is determined that the adjustment target is achieved (then enter the second antifreeze mode), otherwise it enters the next control item; the last control item in the sequence makes the surface temperature Tr no longer meet the first antifreeze mode activation condition, or the control parameter is adjusted to the limit value, and it is determined that the adjustment target is achieved (then enter the second antifreeze mode). In this way, the number of activated control items can be minimized and large temperature fluctuations can be avoided as much as possible.

Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

FIG1 is a schematic diagram of a circulation system of an air conditioner according to an embodiment of the present invention;

FIG2 is a schematic block diagram of an air conditioner according to an embodiment of the present invention;

FIG3 is a schematic structural diagram of an indoor unit of an air conditioner according to an embodiment of the present invention;

FIG4 is a schematic diagram of a method for controlling an air conditioner according to an embodiment of the present invention;

FIG5 is a flow chart of a method for controlling an air conditioner according to an embodiment of the present invention;

FIG. 6 is a flowchart of a method for controlling an air conditioner according to another embodiment of the present invention.

Detailed ways

An air conditioner and a control method thereof according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 6 .

The flow chart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to multiple embodiments of the present invention. In this regard, each square box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and a part of the module, program segment or instruction includes one or more executable instructions for realizing the specified logical function. In some alternative implementations, the function marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous square boxes can actually be executed substantially in parallel, and they can sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each square box in the block diagram and/or flow chart, and the combination of the square boxes in the block diagram and/or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

The flowchart provided in this embodiment is not intended to indicate that the operations of the method will be performed in any particular order. Execution, or all operations of the method are included in all each case. In addition, the method may include additional operations. Within the scope of the technical ideas provided by the method of this embodiment, additional changes can be made to the above method.

It should be noted that the logic and/or steps represented in the flowchart or described in other ways herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or equipment (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or equipment and execute instructions), or used in combination with these instruction execution systems, devices or equipment.

On the one hand, an embodiment of the present invention provides an air conditioner. The air conditioner is used to adjust indoor air, including adjusting the temperature, humidity, air quality of the air, humidifying, dehumidifying, introducing fresh air, etc. The air conditioner of the embodiment of the present invention can be a household air conditioner or a central air conditioner. Specifically, the specific form of the air conditioner can be various forms such as split wall-mounted type, split vertical type, integrated type, patio type, etc. The embodiment of the present invention does not have any limitation on the specific form of the air conditioner.

Fig. 1 is a schematic diagram of a circulation system of an air conditioner according to an embodiment of the present invention; Fig. 2 is a schematic block diagram of an air conditioner according to an embodiment of the present invention; and Fig. 3 is a schematic diagram of the structure of an indoor unit of an air conditioner according to an embodiment of the present invention.

As shown in FIG1 , the air conditioner of the embodiment of the present invention is composed of an evaporator 72, a condenser 74, a compressor 71, an expansion valve 73 and other necessary components to form a vapor compression refrigeration cycle system, so as to output cold air/hot air through an indoor fan 30 to achieve cooling and heating of the indoor environment.

As shown in Fig. 2, the wall-mounted air conditioner indoor unit of the embodiment of the present invention further includes a controller 800. The controller 800 includes a processor 810 and a memory 820, and the memory 820 stores a computer program 821. When the computer program 821 is executed by the processor 810, it is used to implement the air conditioner control method of any of the following embodiments of the present invention.

The processor 810 may be a central processing unit (CPU), or a digital processing unit, etc. The processor 810 sends and receives data via a communication interface. The memory 820 is used to store programs executed by the processor 810. The memory 820 is any medium that can be used to carry or store desired program codes in the form of instructions or data structures and can be accessed by a computer, and may also be a combination of multiple memories 820. The above-mentioned computer program 821 can be downloaded from a computer-readable storage medium to a corresponding computing/processing device or downloaded and installed to the controller 800 via a network (e.g., the Internet, a local area network, a wide area network, and/or a wireless network).

FIG3 illustrates an indoor unit of a split wall-mounted air conditioner. As shown in FIG3 , the indoor unit of the air conditioner includes a housing 10, and the housing 10 defines a storage space for accommodating the main components of the indoor unit, including an evaporator 72, an indoor fan 30, and the like. An indoor air outlet 12 is provided at the lower front side of the housing 10 for blowing out a heat exchange airflow. An indoor air inlet 11 may be provided at the top of the housing 10 for inhaling indoor air. An air duct 15 is defined inside the housing 10, and the outlet of the air duct 15 is connected to the indoor air outlet 12. The indoor fan 30 is arranged in the housing 10, and is used to blow the regulated airflow in the housing 10 out of the indoor air outlet 12 through the air duct 15 to regulate the indoor air. The regulated airflow is, for example, a heat exchange airflow (cold airflow, hot airflow), a purified airflow, a humidified airflow, a fresh airflow, and the like.

The air conditioner further includes an outdoor fan 90. When the outdoor fan 90 is in operation, it is used to realize forced convection heat exchange between outdoor air and the condenser 74. For a split air conditioner, the outdoor fan 90 is arranged in the outdoor unit of the air conditioner. The condenser 74 and the compressor 71 are also arranged in the outdoor unit.

Another aspect of the present invention is to provide a control method for an air conditioner. During the operation of the air conditioner, the surface temperature of the evaporator 72 is often too low due to various factors such as low inlet air temperature and insufficient refrigerant circulation, until ice forms, which is called evaporator freezing. Evaporator freezing will lead to adverse consequences such as water leakage, water blowing, and ice blowing. The control method of the present invention is to prevent and eliminate evaporator freezing.

FIG. 4 is a schematic diagram of a method for controlling an air conditioner according to an embodiment of the present invention.

As shown in FIG. 4 , the air conditioner control method according to the embodiment of the present invention may generally include the following steps:

Step S402: Acquire the surface temperature Tr of the evaporator 72 of the air conditioner. As shown in Fig. 2, the air conditioner may include a temperature detection device 80 for detecting the surface temperature Tr of the evaporator 72. The temperature detection device 80 may be a temperature sensor.

Step S404: If the surface temperature Tr meets the first antifreeze mode activation condition, the first antifreeze mode is activated. The control items of the first antifreeze mode include increasing the air outlet area of the indoor air outlet 12 of the air conditioner, increasing the speed of the indoor fan 30 of the air conditioner, reducing the speed of the outdoor fan 90 of the air conditioner, and increasing the opening of the expansion valve 73 of the air conditioner.

For example, the surface temperature Tr satisfies the first antifreeze mode activation condition including: Tr≤T1, T1 is the preset freezing protection temperature. When Tr≤T1, it is considered that the evaporator 72 has a greater risk of freezing or may have begun to freeze. The critical temperature at which the evaporator 72 is about to freeze can be determined based on multiple experiments to reasonably determine the value of T1, for example, T1 can be 0°C, 1°C, 2°C, etc.

The goal of the first antifreeze mode is to delay the freezing process of the evaporator 72, or eliminate partial freezing. However, during the operation of the first antifreeze mode, the compressor 71 is prevented from being significantly reduced in frequency or even shut down, thereby avoiding causing large fluctuations in indoor temperature.

Step S406: After the first anti-freeze mode reaches the adjustment target, the second anti-freeze mode is activated.

Specifically, the second antifreeze mode includes: controlling the compressor 71 of the air conditioner to reduce the frequency until it stops, so that the air conditioner stops cooling. Since the first antifreeze mode (equivalent to the antifreeze pre-processing process) is added, the second antifreeze mode (equivalent to the antifreeze main process) is processed faster, that is, the time for reducing the frequency and stopping the compressor 71 is shorter, so that the time for indoor temperature fluctuation is shorter.

In addition, after the first anti-freeze mode achieves the adjustment target, the controller 800 can also control the air conditioner to send a freezing reminder to the user to remind the user to clean the filter and check the amount of refrigerant. The reminder can be displayed as a prompt message, lighting a warning light, etc. The inventors recognize that the main reasons for the freezing of the evaporator are as follows: the inlet air temperature of the indoor unit is low; severe throttling and uneven diversion caused by insufficient refrigerant circulation; low indoor fan speed and low indoor circulating air volume; high outdoor fan speed, resulting in excessive heat exchange of the condenser and dirty and clogged indoor filter layer. Based on the above understanding, the embodiments of the present invention particularly design the above four adjustment items in the first anti-freeze mode.

In some embodiments, in the first antifreeze mode, the air conditioner can select one of the above four items according to experimental results, which is called "single-item adjustment mode".

The following describes the preferred control process based on the above-mentioned "single-item adjustment method" with reference to FIG. 5 .

FIG. 5 is a flow chart of a method for controlling an air conditioner according to an embodiment of the present invention.

As shown in FIG5 , a method for controlling an air conditioner according to an embodiment of the present invention sequentially performs the following steps:

Step S502: the air conditioner is in cooling mode.

Step S504: Obtain the surface temperature Tr of the evaporator 72 of the air conditioner.

Step S506: Determine whether the surface temperature Tr meets the first antifreeze mode activation condition. If yes, execute step S508, otherwise continue to execute step S502 to make the air conditioner continue cooling operation.

Step S508: start the first antifreeze mode, that is, increase the air outlet area of the indoor air outlet 12 of the air conditioner, increase the speed of the indoor fan 30 of the air conditioner, reduce the speed of the outdoor fan 90, or increase the opening of the expansion valve 73 of the air conditioner, or only perform one of the above.

Step S510: Determine whether Tr no longer meets the first antifreeze mode activation condition, or whether the control parameter of the control item has been adjusted to the limit value. If so, execute step S512, otherwise continue to execute step S508.

Step S512: Start the second antifreeze mode.

In the above steps, the adjustment target of the first antifreeze mode (hereinafter referred to as "adjustment target") is: the surface temperature Tr no longer meets the first antifreeze mode activation condition, or the adjustment parameter of the adjustment item has been adjusted to the limit value. Of course, it can be understood that if the above adjustment item has been adjusted before adjustment, After reaching its limit value, it is directly judged that the adjustment target of the first antifreeze mode has been achieved.

For example, if the activation condition is set to Tr≤T1, “Tr no longer satisfies the first antifreeze mode activation condition” means Tr>T1.

When the air outlet area of the indoor air outlet 12 is increased, if the air outlet area has been adjusted to the maximum, it indicates that its control parameter has been adjusted to the limit value. When the speed of the indoor fan 30 of the air conditioner is increased, if the speed has been adjusted to the maximum speed and cannot be further increased, it indicates that its control parameter has been adjusted to the limit value. When the opening of the expansion valve 73 of the air conditioner is increased, if the opening has been adjusted to 100%, it indicates that its control parameter has been adjusted to the limit value.

As shown in Fig. 3, the indoor unit of the air conditioner may include at least one air guide plate 51, 52 for adjusting the air outlet area of the indoor air outlet 12, and also has an upper and lower air outlet angle for guiding the indoor air outlet 12. As shown in Fig. 3, there are two air guide plates, namely, an air guide plate 51 and an air guide plate 52 arranged up and down.

In the first antifreeze mode, the control strategy of at least one control item is: adjusting the corresponding control parameter step by step until the control target is achieved. Preferably, each control item is adjusted step by step.

For example, when the air outlet area of the indoor air outlet 12 is increased, if the air outlet area is already the maximum, it is directly judged that the adjustment target is achieved. If the air outlet area is not the maximum, the first step is to appropriately increase the air outlet area, and then obtain Tr. If "Tr no longer meets the first antifreeze mode activation condition", it is judged that the adjustment target is achieved and the adjustment is stopped, otherwise the second step of adjustment is started. After the second step of adjustment, Tr at this time is obtained again. When it is judged that "Tr no longer meets the first antifreeze mode activation condition", it is judged that the adjustment target is achieved and the adjustment is stopped, otherwise the third step of adjustment is started. And so on, until "Tr no longer meets the first antifreeze mode activation condition", or the air outlet area is already the maximum and cannot be adjusted further.

When the speed of the indoor fan 30 of the air conditioner is increased, if the speed is already at the maximum, it is directly judged that the adjustment target is achieved. If the speed is not the maximum, the first step is to appropriately increase the speed, and then obtain Tr. If "Tr no longer meets the first antifreeze mode activation condition", it is judged that the adjustment target is reached and the adjustment is stopped, otherwise the second step of adjustment is started. After the second step of adjustment, Tr at this time is obtained again. When it is judged that "Tr no longer meets the first antifreeze mode activation condition", it is judged that the adjustment target is reached and the speed adjustment is stopped, otherwise the third step of adjustment is started. And so on, until "Tr no longer meets the first antifreeze mode activation condition", or the speed is at the maximum and cannot be adjusted further.

When the speed of the outdoor fan 90 of the air conditioner is reduced, if the speed is already the minimum, it is directly determined that the adjustment target has been achieved. If the speed is not the minimum, the first step is to appropriately reduce the speed, and then obtain Tr. If "Tr no longer meets the first antifreeze mode opening condition", it is determined that the adjustment target has been achieved and the adjustment is stopped. Otherwise, the second step of adjustment is started. After the second step of adjustment, Tr is obtained again and it is determined that "Tr no longer meets the first antifreeze mode opening condition". If the speed no longer meets the first antifreeze mode activation condition, it is determined that the adjustment target is reached and the speed adjustment is stopped, otherwise the third step of adjustment is started. This process is repeated in this way until "Tr no longer meets the first antifreeze mode activation condition" or the speed is already at the minimum and cannot be adjusted further.

When increasing the opening of the expansion valve 73 of the air conditioner, if the opening is already at the maximum, it is directly judged that the adjustment target is achieved. If the opening is not at the maximum, the first step is to appropriately increase the opening, and then obtain Tr. If "Tr no longer meets the first antifreeze mode opening condition", it is judged that the adjustment target is achieved and the adjustment is stopped, otherwise the second step of adjustment is started. After the second step of adjustment, Tr at this time is obtained again. When it is judged that "Tr no longer meets the first antifreeze mode opening condition", it is judged that the adjustment target is achieved and the opening adjustment is stopped, otherwise the third step of adjustment is started. And so on, until "Tr no longer meets the first antifreeze mode opening condition", or the opening is at the maximum and cannot be adjusted further.

In some embodiments, the control items of the first antifreeze mode include increasing the air outlet area of the indoor air outlet 12 of the air conditioner, increasing the speed of the indoor fan 30 of the air conditioner, reducing the speed of the outdoor fan 90, and increasing the opening of the expansion valve 73 of the air conditioner. For example, any two or three of them, or all four of them.

In the first antifreeze mode, each control item is run in a preset order. If the control parameter of the control item in the first order is adjusted to a value below the limit value, so that the surface temperature Tr no longer meets the first antifreeze mode start-up condition, it is determined that the control target is achieved, otherwise it enters the next control item. The control item at the end of the order makes the surface temperature Tr no longer meet the first antifreeze mode start-up condition, or the control parameter is adjusted to the limit value, and it is determined that the control target is achieved.

For example, the first antifreeze mode can use all four control items, and the execution order of the control items is as follows: first, the air outlet area of the indoor air outlet 12 of the air conditioner is increased, then the speed of the indoor fan 30 of the air conditioner is increased, then the speed of the outdoor fan 90 is reduced, and finally the opening of the expansion valve 73 of the air conditioner is increased. The control scheme of this embodiment is introduced below with reference to FIG. 6.

Step S602: The air conditioner is in cooling mode.

Step S604: Acquire the surface temperature Tr of the evaporator 72 of the air conditioner.

Step S606: Determine whether the surface temperature Tr meets the first antifreeze mode activation condition. If yes, execute step S608, otherwise continue to execute step S602 to make the air conditioner continue cooling operation.

Step S608: gradually increasing the air outlet area of the indoor air outlet 12.

Step S610: Determine whether "Tr no longer satisfies the first antifreeze mode activation condition before the air outlet area is adjusted to the maximum value" is true. If so, execute step S622: Control the compressor 71 to reduce the frequency until Shut down and send a freeze reminder to the user. If not, execute step S612.

Step S612: gradually increase the rotation speed of the indoor fan 30.

Step S614: Determine whether "Before the indoor fan speed is adjusted to the maximum value, Tr no longer meets the first antifreeze mode activation condition" is true. If so, execute step S622: control the compressor 71 to reduce the frequency until it stops and send a freezing reminder to the user. Otherwise, execute step S616.

Step S616: gradually reduce the rotation speed of the outdoor fan 90.

Step S618: Determine whether "Before the outdoor fan speed is adjusted to the minimum value, Tr no longer meets the first antifreeze mode activation condition" is true. If so, execute step S622: control the compressor 71 to reduce the frequency until it stops and send a freezing reminder to the user. Otherwise, execute step S620.

Step S620: Increase the opening of the expansion valve 73 until Tr no longer meets the first antifreeze mode activation condition, or the opening of the expansion valve 73 is adjusted to the maximum value.

Step S622: Control the compressor 71 to reduce frequency until it stops, and send a freeze reminder to the user to remind the user to clean the air conditioner filter and check the amount of refrigerant. The reminder can be displayed as a prompt message, light up a warning light, etc.

The antifreeze program of the embodiment of the present invention includes a first antifreeze mode and a second antifreeze mode. When the control items of the first antifreeze mode include increasing the air outlet area of the indoor air outlet 12 of the air conditioner, increasing the speed of the indoor fan 30 of the air conditioner, reducing the speed of the outdoor fan 90, and increasing the opening of the expansion valve 73 of the air conditioner, the second antifreeze mode includes controlling the compressor 71 of the air conditioner to reduce the frequency until it stops. The first antifreeze mode is run first, and when its adjustment target is achieved, the second antifreeze mode is started. After double adjustment, the antifreeze target is gradually achieved, avoiding large fluctuations in indoor temperature caused by directly reducing the frequency or stopping the compressor 71.

During specific control, each control item is run in a preset order. If the control parameter of the control item at the front of the order is adjusted to before the limit value, so that the surface temperature Tr no longer meets the first antifreeze mode activation condition, it is determined that the control target is achieved (then enter the second antifreeze mode), otherwise it enters the next control item; the control item at the end of the order makes the surface temperature Tr no longer meet the first antifreeze mode activation condition, or the control parameter is adjusted to the limit value, and it is determined that the control target is achieved (then enter the second antifreeze mode). In this way, the control items can be reduced as much as possible, and large temperature fluctuations can be avoided as much as possible.

In other embodiments, in the first antifreeze mode, various control items are executed simultaneously; when the surface temperature Tr no longer meets the first antifreeze mode activation condition, or the control parameters of each control item have been adjusted to the limit value, it is determined that the control target is achieved.

By now, those skilled in the art will recognize that although the present invention has been fully shown and described herein, However, many other variations or modifications that conform to the principles of the present invention can be directly determined or derived from the contents disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all these other variations or modifications.

Claims

A method for controlling an air conditioner, comprising:

Obtaining the evaporator surface temperature Tr of the air conditioner;

If the surface temperature Tr meets the first antifreeze mode activation condition, the first antifreeze mode is activated; the control items of the first antifreeze mode include increasing the air outlet area of the indoor air outlet of the air conditioner, increasing the indoor fan speed of the air conditioner, decreasing the outdoor fan speed of the air conditioner, and increasing the opening of the expansion valve of the air conditioner.

After the first antifreeze mode reaches the adjustment target, the second antifreeze mode is activated.
The control method according to claim 1, wherein

The adjustment target is: to make the surface temperature Tr no longer meet the first antifreeze mode activation condition, or the control parameter of the control item has been adjusted to a limit value.
The control method according to claim 2, wherein

The control strategy of at least one of the control items is: adjusting the corresponding control parameters step by step until the control target is achieved.
The control method according to any one of claims 1 to 3, wherein

The control items of the first antifreeze mode include increasing the air outlet area of the indoor air outlet of the air conditioner, increasing the speed of the indoor fan of the air conditioner, decreasing the speed of the outdoor fan of the air conditioner, and increasing the opening of the expansion valve of the air conditioner;

In the first antifreeze mode, each of the control items is operated in a preset order; and

If the control parameter of the control item in the previous order is adjusted to a limit value so that the surface temperature Tr no longer meets the first antifreeze mode activation condition, it is determined that the control target is achieved, otherwise the next control item is entered;

The last control item in the sequence makes the surface temperature Tr no longer meet the first antifreeze mode activation condition, or the control parameter is adjusted to a limit value, and it is determined that the control target is achieved.
The control method according to claim 4, wherein

The execution order of the control items of the first antifreeze mode is from front to back: increasing the air outlet area of the indoor air outlet of the air conditioner, increasing the speed of the indoor fan of the air conditioner, and reducing the speed of the indoor fan of the air conditioner. The outdoor fan speed is increased and the expansion valve opening of the air conditioner is increased.
The control method according to claim 4, wherein

The control items of the first antifreeze mode include increasing the air outlet area of the indoor air outlet of the air conditioner, increasing the speed of the indoor fan of the air conditioner, decreasing the speed of the outdoor fan of the air conditioner, and increasing the opening of the expansion valve of the air conditioner;

In the first antifreeze mode, various control items are executed simultaneously;

When the surface temperature Tr no longer satisfies the first antifreeze mode activation condition, or the control parameters of each of the control items have been adjusted to the limit value, it is determined that the control target is achieved.
The control method according to any one of claims 1 to 3, wherein

The surface temperature Tr satisfies the first antifreeze mode activation condition including: Tr≤T1, T1 is a preset freezing protection temperature.
The control method according to any one of claims 1 to 3, wherein

The second antifreeze mode includes: controlling the compressor of the air conditioner to reduce frequency until it stops.
The control method according to any one of claims 1 to 3, further comprising:

After the first anti-freeze mode achieves the adjustment target, the air conditioner is controlled to send a freezing reminder to the user to remind the user to clean the filter of the air conditioner and check the amount of refrigerant.
An air conditioner comprises a controller, wherein the controller comprises a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the computer program is used to implement the control method according to any one of claims 1 to 9.