EP3734178B1

EP3734178B1 - Control method for air conditioner

Info

Publication number: EP3734178B1
Application number: EP18895635.3A
Authority: EP
Inventors: Chao AN; Chao GU
Original assignee: Qingdao Haier Air Conditioning Electric Co Ltd; Haier Smart Home Co Ltd
Current assignee: Qingdao Haier Air Conditioning Electric Co Ltd; Haier Smart Home Co Ltd
Priority date: 2017-12-25
Filing date: 2018-10-18
Publication date: 2024-04-10
Anticipated expiration: 2038-10-18
Also published as: EP3734178A4; EP3734178A1; US20210071924A1; CN108224704A; WO2019128397A1

Description

FIELD

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

BACKGROUND

An air conditioner is an apparatus that is capable of cooling or heating an indoor environment. During the cooling operation of the air conditioner, an indoor unit may freeze due to various reasons such as low indoor and outdoor ambient temperatures, long piping connection, and lack of freon, which in turn causes undesired phenomena such as poor cooling effect, water leakage, and pipe cracks, thus seriously affecting the user experience.
Therefore, there is a need in the art for a new control method for an air conditioner to solve the above problems.
Prior art documents that provide relevant information in regard of the present invention, are outlined in the following paragraphs.
European patent application EP2428751A2 relates to an air conditioner comprising a compressor and an indoor heat exchanger, and in particular to a control method for the air conditioner wherein the frequency of the compressor is adapted based on a temperature sensor of an indoor heat exchanger.
Likewise, the Chinese patent application CN103115417A relates to an air conditioner comprising a compressor and an indoor unit, and to a control method thereof. The air conditioner is specifically configured for operation at a low temperature range, including refrigeration.
Further relevant air conditioners and control methods thereof, are disclosed in Chinese patent applications CN104566645A and CN104697118A .

SUMMARY

In order to solve the above problem in the related art, that is, to solve the problem that an indoor unit of the air conditioner may easily freeze to cause phenomena such as poor cooling effect of the air conditioner, water leakage of the air conditioner or pipe cracks, the present invention provides a control method for an air conditioner according to claim 1. The air conditioner includes a compressor and an indoor unit, and the control method includes: acquiring a coil temperature of the indoor unit; and selectively adjusting the frequency of the compressor according to the coil temperature of the indoor unit, and after the compressor has been operated for a first preset duration, if the coil temperature of the indoor unit is lower than a fourth preset temperature for a second preset duration, stopping operation of the compressor for a third preset duration.
In a preferred technical solution of the above control method, the step of "selectively adjusting the frequency of the compressor according to the coil temperature of the indoor unit" includes: operating the compressor at a decreased frequency, if the coil temperature of the indoor unit is lower than a first preset temperature.
In a preferred technical solution of the above control method, the step of "selectively adjusting the frequency of the compressor according to the coil temperature of the indoor unit" further includes: maintaining the operating frequency of the compressor unchanged, if the coil temperature of the indoor unit is higher than or equal to the first preset temperature and lower than or equal to a second preset temperature, the first preset temperature being lower than the second preset temperature.
In a preferred technical solution of the above control method, the step of "selectively adjusting the frequency of the compressor according to the coil temperature of the indoor unit" further includes: operating the compressor at an increased frequency, if the coil temperature of the indoor unit is higher than the second preset temperature and lower than or equal to a third preset temperature, the second preset temperature being lower than the third preset temperature.
In a preferred technical solution of the above control method, the control method further includes: after stopping the operation, if the coil temperature of the indoor unit becomes higher than or equal to a fifth preset temperature, resuming the operation of the compressor, the fourth preset temperature being lower than the fifth preset temperature.
In a preferred technical solution of the above control method, when the coil temperature of the indoor unit is lower than the first preset temperature, the compressor is operated at a decreased frequency; when the coil temperature of the indoor unit is higher than or equal to the first preset temperature and lower than or equal to the second preset temperature, the operating frequency of the compressor is maintained unchanged; and when the coil temperature of the indoor unit is higher than the second preset temperature and lower than or equal to the third preset temperature, the compressor is operated at an increased frequency. With these arrangements, that is, by setting values of the first preset temperature, the second preset temperature and the third preset temperature, the frequency of the compressor is adjusted for different temperature intervals. By adopting the above described control method of the present invention, the frequency of the compressor can be adjusted according to the coil temperature of the indoor unit in practical applications, thereby ensuring that the indoor unit does not freeze and further effectively realizing anti-freezing protection for the air conditioner during the cooling operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic flowchart of a control method for an air conditioner of the present disclosure;
FIG. 2 is a schematic flowchart of a first embodiment of the control method for the air conditioner of the present disclosure; and
FIG. 3 is a schematic flowchart of a second embodiment of the control method for the air conditioner of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. It should be understood by those skilled in the art that the drawings are only used to explain the technical principles of the present invention, and are not intended to limit the scope of protection of the present invention which is defined in the appended claims.
It should be noted that in the description of the present disclosure, terms "first", "second", "third", "fourth" and "fifth" are used for descriptive purpose only, and should not be interpreted as indicating or implying relative importance.
In view of the problem pointed out in the "BACKGROUND OF THE INVENTION" that the indoor units of existing air conditioners may easily freeze to cause phenomena such as poor cooling effect of the air conditioner, water leakage of the air conditioner or pipe cracks, the present invention provides a control method for an air conditioner, which aims to avoid the freezing of the indoor unit of the air conditioner, and thus effectively solve the problem that the indoor unit is easy to freeze.
Specifically, reference is made to FIG. 1, which is a schematic flowchart of a control method for an air conditioner. As shown in FIG. 1 is provided a control method for an air conditioner, wherein the air conditioner includes a compressor and an indoor unit, and the control method includes: acquiring a coil temperature of the indoor unit; and selectively adjusting the frequency of the compressor according to the coil temperature of the indoor unit.
In the present invention, with the operation of the air conditioner, the coil temperature of the indoor unit will also change accordingly. According to the different coil temperatures of the indoor unit, the frequency of the compressor can be controlled differently. In practical applications, the coil temperature of the indoor unit can be detected in real time by an indoor unit coil sensor. Of course, the coil temperature of the indoor unit may also be an experimental value obtained by those skilled in the art based on experiments under specific working conditions, or an empirical value obtained from experience. That is, those skilled in the art can choose any method to obtain the coil temperature of the indoor unit according to the actual situation, as long as the operating frequency of the compressor can be adjusted according to the change of the coil temperature of the indoor unit. By adjusting the frequency of the compressor, the compressor can be always operated within a suitable frequency range, which not only can ensure the cooling effect, but also can prevent the indoor unit of the air conditioner from freezing.
Preferably, the step of "selectively adjusting the frequency of the compressor according to the coil temperature of the indoor unit" includes: operating the compressor at a decreased frequency, if the coil temperature of the indoor unit is lower than a first preset temperature. That is, according to the setting of the first preset temperature, an initial conclusion of operating the compressor at a decreased frequency can be given. Those skilled in the art can flexibly set the specific value of the first preset temperature in practical applications, as long as the boundary point determined by the first preset temperature can give the conclusion that the compressor needs to be operated at a decreased frequency, and the indoor unit of the air conditioner will not freeze after the adjustment of the operating frequency of the compressor.
Further, the step of "selectively adjusting the frequency of the compressor according to the coil temperature of the indoor unit" further includes: maintaining the operating frequency of the compressor unchanged, if the coil temperature of the indoor unit is higher than or equal to the first preset temperature and lower than or equal to a second preset temperature, the first preset temperature being lower than the second preset temperature. Similar to the first preset temperature, those skilled in the art can flexibly set the specific value of the second preset temperature in practical applications, as long as the boundary points determined by the first preset temperature and the second preset temperature can give the conclusion that the current operating frequency of the compressor needs to be maintained unchanged, and the indoor unit of the air conditioner will not freeze.
Still further, the step of "selectively adjusting the frequency of the compressor according to the coil temperature of the indoor unit" further includes: operating the compressor at an increased frequency, if the coil temperature of the indoor unit is higher than the second preset temperature and lower than or equal to a third preset temperature, the second preset temperature being lower than the third preset temperature. Similar to the first preset temperature and the second preset temperature, those skilled in the art can flexibly set the specific value of the third preset temperature in practical applications, as long as the boundary point determined by the third preset temperature can give the conclusion that the compressor needs to be operated at an increased frequency, and the indoor unit of the air conditioner will not freeze after the adjustment of the operating frequency of the compressor.
By setting the first preset temperature, the second preset temperature and the third preset temperature as described above, the coil temperature of the indoor unit can be divided into different temperature intervals, and the compressor can be adjusted accordingly within each temperature interval and the compressor can be operated at the most suitable frequency. This method is more advantageous for the adjustment of the compressor frequency. At the same time, by detecting the coil temperature of the indoor unit in real time and adjusting the compressor frequency in real time, a situation that the operating frequency of the compressor is too high or too low can be effectively avoided, thereby preventing the indoor unit of the air conditioner from freezing.
It should be noted that in the above technical solution of the present invention, the temperature intervals divided according to the first preset temperature, the second preset temperature and the third preset temperature may be further divided. For example, when the coil temperature of the indoor unit is higher than the first preset temperature and lower than or equal to the second preset temperature, the temperature interval between the first preset temperature and the second preset temperature may be re-divided into multiple temperature sub-intervals, and different adjustment strategies for the compressor frequency are set within the temperature sub-intervals. Those skilled in the art may set the same or different ways of adjusting the compressor frequency according to different temperature intervals in practical applications, so that the air conditioner can be operated stably in different environments and the indoor unit can be effectively prevented from freezing.
In addition, it should also be noted that when controlling the compressor frequency to increase/decrease, the compressor frequency may be controlled to increase/decrease slowly, or the compressor frequency may be controlled to increase/decrease fast. In practice, those skilled in the art may flexibly set the adjustment speed of increasing/decreasing the compressor frequency, as long as the speed setting enables the compressor frequency to smoothly increase/decrease.
According to the invention, after the compressor has been operated for a first preset duration, if the coil temperature of the indoor unit is lower than a fourth preset temperature for a second preset duration, the operation of the compressor is stopped for a third preset duration. In practical applications, the fourth preset temperature may be set to be lower than the above first preset temperature. The fourth preset temperature may be an experimental temperature value obtained by those skilled in the art based on experiments under specific working conditions, or may be an empirical temperature value obtained from experience. Those skilled in the art can flexibly set the specific temperature value of the fourth preset temperature in practical applications, as long as the boundary point determined by the fourth preset temperature can give the conclusion that the operation of the compressor needs to be stopped, and the operating mode of the compressor and the anti-freezing function of the air conditioner can be optimized. In addition, the first preset duration, the second preset duration and the third preset duration can be flexibly adjusted and set according to actual conditions, as long as the boundary points determined by the above-mentioned first preset duration, the second preset duration, and the third preset duration can optimize the anti-freezing function of the air conditioner.
Further, the control method further includes: after stopping the operation of the compressor, if the coil temperature of the indoor unit becomes higher than or equal to a fifth preset temperature, resuming the operation of the compressor, the fourth preset temperature being lower than the fifth preset temperature. That is, after the operation of the compressor has been stopped for the third preset duration, if the coil temperature of the indoor unit rises to or above the fifth preset temperature, the operation of the compressor needs to be resumed. In practical applications, the fifth preset temperature may be set to be equal to the above-mentioned third preset temperature. Of course, this is not limiting, and the fifth preset temperature may also be other temperature values. In practical applications, those skilled in the art may flexibly set the specific temperature value of the fifth preset temperature, as long as the boundary point determined by the fifth preset temperature can give the conclusion that the operation of the compressor needs to be resumed, and the operating mode of the compressor and the anti-freezing function of the air conditioner can be optimized.
As shown in FIG. 2, the above control method can include the following steps s1 to s4.
Step s1, operating the air conditioner in a cooling mode at the maximum capacity.
Step s2: acquiring the coil temperature of the indoor unit.
wherein the coil temperature of the indoor unit may be directly detected by the temperature sensor, or it may be an experimental temperature value obtained by those skilled in the art based on experiments under specific working conditions, or an empirical temperature value obtained from experience.
Step s3, dividing the temperature interval of the value of the coil temperature of the indoor unit.
wherein the temperature interval of the coil temperature of the indoor unit may be divided according to the indoor temperature, or may be divided according to the outdoor ambient temperature, as long as the range determined by the temperature interval enables the operating frequency of the compressor to be adjusted and can prevent the air conditioner from freezing.
Step s4: selectively adjusting the frequency of the compressor according to the temperature interval of the coil temperature of the indoor unit.
In the above method, steps s1 and s2 may be executed sequentially or simultaneously. Those skilled in the art may flexibly set the execution of steps s1 and s2 in practical applications, as long as the coil temperature of the indoor unit can be acquired through the setting.
The technical solution of the present invention is further explained below in combination with specific embodiments:
In a possible situation, as shown in FIG. 3, after the air conditioner is started, or while the air conditioner is started, the coil temperature TM of the indoor unit is detected by the indoor unit coil temperature sensor disposed on the air conditioner. The first preset temperature is set to 6°C, the second preset temperature is set to 8°C, and the third preset temperature is set to 10°C. The operating frequency of the compressor is adjusted by judging the temperature interval of the indoor unit coil temperature TM. If TM<6°C, the frequency of the compressor is decreased at a constant rate of 1Hz/10s; if 6°C≤TM≤8°C, the frequency of the compressor is maintained unchanged; and if 8°C<TM≤10°C, the frequency of the compressor is increased at a constant rate of 1Hz/10s.
During the operation of the compressor, the operation duration thereof is recorded. After the compressor has been operated for 6 minutes, if TM<2°C for 10 seconds, the operation of the compressor is stopped for a minimum duration of 5 minutes and a maximum duration of 9 minutes; when TM rises above 10°C, the normal operation of the compressor is resumed.
It should be understood that the specific values of the above parameters do not serve as limitations, but are only used to help understand the solutions.

Claims

A control method for an air conditioner, the air conditioner comprising a compressor and an indoor unit, wherein the control method comprises:
acquiring coil temperature of the indoor unit; and

selectively adjusting frequency of the compressor according to the coil temperature of the indoor unit, and

after the compressor has been operated for a first preset duration, if the coil temperature of the indoor unit is lower than a fourth preset temperature for a second preset duration, stopping operation of the compressor for a third preset duration.
The control method according to claim 1, wherein the step of "selectively adjusting frequency of the compressor according to the coil temperature of the indoor unit" comprises:
operating the compressor at a decreased frequency, if the coil temperature of the indoor unit is lower than a first preset temperature.
The control method according to claim 2, wherein the step of "selectively adjusting frequency of the compressor according to the coil temperature of the indoor unit" further comprises:
maintaining the operating frequency of the compressor unchanged, if the coil temperature of the indoor unit is higher than or equal to the first preset temperature and lower than or equal to a second preset temperature, and

wherein the first preset temperature is lower than the second preset temperature.
The control method according to claim 3, wherein the step of "selectively adjusting frequency of the compressor according to the coil temperature of the indoor unit" further comprises:
operating the compressor at an increased frequency, if the coil temperature of the indoor unit is higher than the second preset temperature and lower than or equal to a third preset temperature, and

wherein the second preset temperature is lower than the third preset temperature.
The control method according to claim 1, further comprising:
after stopping the operation, if the coil temperature of the indoor unit becomes higher than or equal to a fifth preset temperature, resuming the operation of the compressor,

wherein the fourth preset temperature is lower than the fifth preset temperature.
The control method according to claim 3, further comprising:
after stopping the operation, if the coil temperature of the indoor unit becomes higher than or equal to a fifth preset temperature which is higher than the fourth preset temperature, resuming the operation of the compressor.