KR102437381B1 - Air conditioner and Method for controlling it - Google Patents

Abstract

The present invention provides an air conditioner including an outdoor unit having a compressor and an outdoor heat exchanger, and an indoor unit having an expansion valve and an indoor heat exchanger, comprising: a human body detecting device configured to detect the number of occupants in an air conditioning space; a memory for storing information on a plurality of levels of an opening degree of an expansion valve corresponding to the number of occupants; and a control unit electrically connected to the human body sensing device and the memory and configured to control the expansion valve, wherein the control unit is based on the number of first occupants detected at the initial stage of operation of the air conditioner and the corresponding opening degree information. Provided are an air conditioner and a control method therefor, wherein an opening degree of the expansion valve is controlled to an N-th level, and the opening degree of the expansion valve is controlled to a minimum opening degree when the temperature of the air conditioning space reaches a set temperature.

Description

Air conditioner and method for controlling it

The present invention relates to an air conditioner capable of appropriately regulating the amount of refrigerant circulating in a refrigerant cycle based on a set temperature and the number of occupants, and a method for controlling the same.

In general, an air conditioner includes a compressor for compressing a refrigerant, an indoor heat exchanger for exchanging heat with indoor air, an expansion valve for expanding the refrigerant, and an outdoor heat exchanger for exchanging heat with outdoor air.

The compressor and the outdoor heat exchanger may be provided in an outdoor unit, and the indoor heat exchanger may be provided in an indoor unit. The expansion valve may be provided in at least one of the indoor unit and the outdoor unit.

Such an air conditioner may include a heating mode and a cooling mode, and at least one of a driving frequency of a compressor provided in the air conditioner and an opening degree of an expansion valve may be adjusted based on a set temperature.

Recently, research has been conducted to increase the user's comfort level by adjusting the opening degree of the expansion valve based on the number of occupants in the air conditioning space.

For example, Japanese Unexamined Patent Publication No. Hei 11-311437 (hereinafter referred to as "conventional air conditioner") discloses a feature of adjusting the refrigerant flow rate based on the presence or absence of a person in the air conditioning space.

Specifically, the conventional air conditioner determines whether or not a person exists in the air conditioning space through the imaging device. In addition, the refrigerant flow rate flowing through the indoor unit is controlled by distinguishing between the human presence area and the person's absence area.

On the other hand, since the conventional air conditioner controls the expansion valve based on a preset control value (that is, the opening degree of the expansion valve) according to the number of occupants, there is a problem in that it cannot respond to changes in the environment in which the air conditioner is installed.

For example, according to the conventional air conditioner, since both the air conditioner installed in a relatively high temperature environment and the air conditioner installed in a relatively low temperature area operate with the same control logic, the refrigerant cycle is controlled to the optimum refrigerant flow rate. There is a problem that is difficult to become.

In addition, the conventional air conditioner has a problem in that the opening degree of the expansion valve cannot be flexibly adjusted according to a change in the number of occupants and a change in the temperature of the air conditioning space.

The present invention is to solve the above problems, and provides an air conditioner capable of minimizing the use of refrigerant and saving energy by continuously controlling the opening degree of an expansion valve in response to changes in the environment of an air conditioning space, and a method for controlling the same aim to do

Another object of the present invention is to provide an air conditioner capable of minimizing loss of refrigerant by controlling the amount of refrigerant circulating in a refrigerant cycle to the minimum possible, and a method for controlling the same.

In order to achieve the above object, the present invention is an air conditioner including an outdoor unit having a compressor and an outdoor heat exchanger, and an indoor unit having an expansion valve and an indoor heat exchanger. ; a memory for storing information on a plurality of levels of an opening degree of an expansion valve corresponding to the number of occupants; and a control unit electrically connected to the human body sensing device and the memory and configured to control the expansion valve, wherein the control unit is based on the number of first occupants detected at the initial stage of operation of the air conditioner and the corresponding opening degree information. An air conditioner is provided, wherein an opening degree of the expansion valve is controlled to an N-th level, and the opening degree of the expansion valve is controlled to a minimum opening degree when the temperature of the air conditioning space reaches a set temperature.

When the temperature of the air conditioning space reaches a set temperature, the controller may control the opening degree of the expansion valve to a first level that is a minimum opening degree.

The control unit controls the opening degree of the expansion valve to the first level, and after a predetermined period of time elapses, the second number of occupants sensed again by the human body detection device and the first occupant number sensed immediately before are compared with each other. An opening degree of the expansion valve may be controlled.

When the number of first occupants is equal to the number of second occupants, the controller may control the opening degree of the expansion valve to an N-1 th level.

When the number of first occupants is different from the number of second occupants, the controller may control the expansion valve to an opening degree one level lower than an opening degree of the expansion valve stored in the memory in response to the second number of occupants.

The controller may control the opening degree of the expansion valve based on a first temperature difference between the initial temperature of the air conditioning space and the set temperature and a second temperature difference between the temperature of the air conditioning space and the set temperature after the lapse of the predetermined time.

When the first temperature difference is greater than the second temperature difference, the controller may maintain the opening degree of the expansion valve at an N-1 th level.

When the first temperature difference is less than or equal to the second temperature difference, the controller may control the opening degree of the expansion valve to an N+1th level.

When the temperature of the air conditioning space reaches the set temperature again and the opening degree of the expansion valve is greater than the minimum opening degree, the controller may control the opening degree of the expansion valve to the first level which is the minimum opening degree again.

In addition, the present invention provides a first occupant number detection step in which the number of occupants is detected by a human body sensor; an initial control step in which an opening degree of the expansion valve is controlled to an N-th level corresponding to a first number of occupants among a plurality of preset levels; a minimum control step of controlling the expansion valve to a minimum opening degree when the temperature of the air conditioning space reaches a set temperature; a second occupant number detection step in which the number of occupants is detected again by a human body sensor after a predetermined time has elapsed from the minimum control step; and a first opening degree adjusting step of controlling the opening degree of the expansion valve to the N-1th level based on a result of comparing the first number of occupants and the second number of occupants.

The first opening degree adjustment step may include: a occupant number comparison step in which the first occupant number and the second occupant number are compared; and adjusting the opening degree of the expansion valve to an N-1 th level when the number of first occupants and the number of second occupants are the same in the step of comparing the number of occupants.

In the first opening degree adjustment step, when the first number of occupants and the second number of occupants are different in the step of comparing the number of occupants, the N-th level may be changed to correspond to the second number of occupants. And, the opening degree of the expansion valve may be adjusted to the N-1th level.

The control method of the air conditioner may further include, after the first opening degree adjusting step, a second opening degree adjusting step of controlling the opening degree of the expansion valve based on the temperature of the air conditioning space and the set temperature.

The second opening degree control step may include a temperature difference comparison step of comparing a first temperature difference between an initial temperature and a set temperature of the air conditioning space and a second temperature difference between the temperature of the air conditioning space and a set temperature after the lapse of the predetermined time; and changing the opening degree of the expansion valve to the N+1th opening degree when the first temperature difference is less than or equal to the second temperature difference in the temperature difference comparison step.

After the second opening degree adjusting step, when the temperature of the air conditioning space reaches the set temperature, the minimum opening degree of the expansion valve may be changed or maintained to the minimum opening degree again.

According to the present invention, it is possible to provide an air conditioner capable of minimizing the use of refrigerant and saving energy by continuously controlling an opening degree of an expansion valve in response to a change in the environment of an air conditioning space, and a control method thereof.

In addition, according to the present invention, it is possible to provide an air conditioner capable of minimizing the loss of the refrigerant by controlling the amount of refrigerant circulating in the refrigerant cycle to the minimum possible, and a method for controlling the same.

1 is a flowchart illustrating a refrigerant of an air conditioner according to an embodiment of the present invention.
2 shows a connection relationship of main components of an air conditioner according to an embodiment of the present invention.
3 is a flowchart illustrating a method for controlling an air conditioner according to an embodiment of the present invention.
FIG. 4 is a flow chart embodying some steps (first opening degree adjustment step) of FIG. 3 .
FIG. 5 is a flow chart embodying some other steps (second opening degree adjustment step) of FIG. 3 .

Hereinafter, an air conditioner and a control method thereof according to the present invention will be described in detail with reference to the accompanying drawings. The accompanying drawings show exemplary forms of the present invention, which are only provided to explain the present invention in detail, and the technical scope of the present invention is not limited thereby.

In addition, regardless of the reference numerals, the same or corresponding components are given the same reference numerals and redundant description thereof will be omitted, and for convenience of explanation, the size and shape of each component shown may be exaggerated or reduced. have.

1 is a flowchart illustrating a refrigerant of an air conditioner according to an embodiment of the present invention.

Referring to FIG. 1 , the air conditioner 10 according to the embodiment of the present invention includes a compressor 100 , an indoor heat exchanger 200 , an expansion valve 300 , and an outdoor heat exchanger 400 . In the illustrated embodiment, "I" may indicate an indoor unit and "O" may indicate an outdoor unit.

Although the expansion valve 300 is illustrated in FIG. 1 as being provided in the indoor unit I, the expansion valve 300 may be provided in the outdoor unit O, and may be provided in the indoor unit I and the outdoor unit O, respectively. It is also possible to be provided.

The compressor 100 is configured to compress the refrigerant. That is, the compressor 100 may be formed to pressurize a low-temperature and low-pressure refrigerant into a high-temperature and high-pressure refrigerant. One or more compressors 100 may be provided in the air conditioner 10 . The compressor 100 may be an inverter compressor with adjustable frequency.

When a plurality of compressors 100 are provided in the air conditioner 10, the plurality of compressors may be provided in series and/or in parallel along the flow direction of the refrigerant.

The indoor heat exchanger 200 may be formed to exchange heat with indoor air. That is, the indoor heat exchanger 200 may be formed so that indoor air and the refrigerant flowing into the indoor heat exchanger 200 exchange heat.

For example, the indoor heat exchanger 200 may perform a function of an evaporator in a cooling mode of the air conditioner 10 and a function of a condenser in a heating mode.

The expansion valve 300 may be formed to expand the refrigerant. For example, in the heating mode, the expansion valve 300 may expand the refrigerant toward the outdoor heat exchanger 400 functioning as an evaporator. Alternatively, in the cooling mode, the expansion valve 300 may expand the refrigerant directed to the indoor heat exchanger 200 functioning as an evaporator.

The expansion valve 300 may be controlled by a control unit C, which will be described later. For example, the expansion valve 300 may be controlled such that its opening degree is adjusted by the control unit C.

For example, as the opening degree of the expansion valve 300 increases, the amount of refrigerant circulating in the refrigerant cycle may increase. When the amount of refrigerant circulating in the refrigerant cycle is increased, the amount of refrigerant exchanging heat between the indoor heat exchanger 200 and the outdoor heat exchanger 400 may be increased, so that cooling and heating performance may be increased.

Conversely, as the opening degree of the expansion valve 300 decreases, the amount of refrigerant circulating in the refrigerant cycle may be reduced. When the amount of refrigerant circulating in the refrigerant cycle is reduced, the amount of refrigerant exchanging heat between the indoor heat exchanger 200 and the outdoor heat exchanger 400 may be reduced, thereby reducing cooling/heating performance.

Here, the heating/cooling performance may mean a time for which the temperature of the air conditioning space reaches the set temperature.

The outdoor heat exchanger 400 may be formed to exchange heat with outdoor air. That is, the outdoor heat exchanger 400 may be formed so that outdoor air and the refrigerant flowing into the outdoor heat exchanger 400 exchange heat.

For example, the outdoor heat exchanger 400 may perform a function of a condenser in a cooling mode of the air conditioner 10 and a function of an evaporator in a heating mode.

The indoor heat exchanger 200 and the outdoor heat exchanger 400 may be a fin-tube type heat exchanger. In addition, an indoor fan 210 may be provided on the indoor heat exchanger 200 side, and an outdoor fan 410 may be provided on the outdoor heat exchanger 400 side.

The air conditioner 10 may include a flow path switching valve 600 for switching the circulation direction of the refrigerant when the cooling mode and the heating mode are switched. The flow path switching valve 600 may be formed as a four-way valve.

For example, the flow path switching valve 600 may be configured to guide the refrigerant discharged from the compressor 100 to the outdoor unit in the cooling mode, and guide the refrigerant discharged from the compressor 100 to the indoor unit in the heating mode.

An accumulator 500 may be provided at one side of the compressor 100 . The accumulator 500 may be configured to separate the refrigerant directed to the compressor 100 into a gaseous refrigerant and a liquid refrigerant, and supply only the gaseous refrigerant to the compressor 100 .

Meanwhile, the air conditioner 10 may have different cooling/heating performance depending on the environment in which it is installed, and user comfort or satisfaction may also vary.

For example, the time required until the temperature of the air conditioning space reaches the set temperature may be an index for the user's comfort level or satisfaction. If the required time is too long, it may cause discomfort to the user, and if it is too short, it may cause discomfort to the user.

The required time may be predetermined as a desired value through experimentation, and may be, for example, 5 minutes to 15 minutes. Preferably, the required time may be 10 minutes.

In order to allow the temperature of the air conditioning space to reach the set temperature according to the required time, the opening degree of the expansion valve 300 may be adjusted. And, by adjusting the opening degree of the expansion valve 300 , the amount of refrigerant circulating in the refrigerant cycle may be adjusted.

However, in general, the opening degree of the expansion valve 300 is already set by an administrator before the product is released. In particular, recently, research on an air conditioner capable of detecting the number of occupants and adjusting the opening degree of the expansion valve 300 based on the sensed number of occupants is being conducted.

On the other hand, when the amount of the refrigerant circulating in the refrigerant cycle is unnecessarily large, there is a problem in that the amount of energy consumption is increased as well as the amount of loss of the refrigerant is increased. Therefore, it is desirable to control the amount of refrigerant circulating in the refrigerant cycle to the minimum possible as the number of occupants changes or the temperature of the air conditioning space changes.

In this regard, it will be described in detail below with further reference to other drawings.

2 shows a connection relationship of main components of an air conditioner according to an embodiment of the present invention.

1 and 2 together, the air conditioner 10 according to an embodiment of the present invention has a memory (M) for storing information on the opening degree of the human body detecting device 710 , the temperature sensor 720 , and the expansion valve 300 . ), and a control unit (C) electrically connected to the memory (M).

In addition, the air conditioner 10 may further include a command input unit 800 to which an operation mode and a set temperature may be input.

The human body sensing device 710 may be formed to detect the number of occupants existing in the air conditioning space. The human body detecting device 710 may be formed of an infrared camera or a thermal imaging camera. Since many of these human body sensing devices 710 are generally known, a detailed description thereof will be omitted.

The temperature sensor 720 may be provided in the indoor unit I or a remote controller (not shown) installed on the wall of the air conditioning space. The temperature sensor 720 may be formed to sense the temperature of the air conditioning space in real time.

The memory M may be configured to store an opening value of the expansion valve 300 based on the number of occupants. Here, the value of the opening degree of the expansion valve 300 is a value derived through an experiment, and may be input and stored in the memory M by an administrator at the initial stage of product manufacturing.

The memory M may store the values of the opening degree of the expansion valve 300 defined as a plurality of preset levels. The plurality of levels may be N levels, and N may be 1 to 5. Of course, it is also possible to further subdivide the plurality of levels.

For example, the opening value of the expansion valve 300 may be defined and stored in the memory M as a first level to a fifth level. In this case, the first level may mean an opening degree of 10%, the second level may mean an opening degree of 30%, the third level may mean an opening degree of 50%, and the fourth level may mean an opening degree of 70% It may mean an opening degree of %, and the fifth level may mean an opening degree of 100%.

In addition, the memory M may be stored so that the value of the opening degree of the expansion valve 300 corresponds to the number of occupants.

For example, 0 occupants may correspond to the first level, 2 occupants may correspond to the second level, 3 occupants may correspond to the third level, and 4 occupants may correspond to the fourth level It can correspond to the level, and the number of occupants of 5 or more can correspond to the fifth level.

Accordingly, when the number of occupants of the air conditioning space sensed by the human body sensor 710 is three, the expansion valve 300 may be controlled by the controller C at an opening degree of 50%. To this end, the control unit (C) may be electrically connected to the human body detection sensor (710) and the memory (M).

Since the opening value of the expansion valve 300 stored in the memory M is a value determined through an experiment, the opening value may not be the optimal value depending on changes in the environment in which the air conditioner is installed.

Therefore, in order to maintain the performance of the air conditioner while maintaining the amount of the refrigerant circulating in the refrigerant cycle to the minimum possible (that is, to maintain the predetermined minimum amount, not "0"), it expands according to the environmental change of the air conditioning space. It is necessary to change the opening degree of the valve 300 .

Specifically, the control unit C stores the number of occupants (hereinafter, also referred to as “first occupants”) detected by the human body sensor 710 at the initial stage of driving of the air conditioner and stored in the memory M to correspond thereto. The opening degree of the expansion valve 300 may be controlled to the Nth level based on the opening degree information.

That is, the controller C may adjust the opening degree of the expansion valve 300 to the Nth level based on the opening degree information stored in the memory M as a value corresponding to the first number of occupants. The control of the opening degree of the expansion valve 300 may be a basic control generally used in the control based on the number of occupants.

Meanwhile, when the temperature of the air conditioning space reaches a set temperature, the controller C may control the opening degree of the expansion valve 300 to a minimum opening degree. Here, the minimum opening degree may be a first level among the first to fifth levels described above.

That is, when the temperature of the air conditioning space reaches the set temperature, the controller C may control the opening degree of the expansion valve 300 to a first level, which is the minimum opening degree.

This is because, when the temperature of the air conditioning space reaches the set temperature, the temperature of the air conditioning space can be maintained even with a minimum amount of refrigerant. By such control, the present invention can minimize the amount of refrigerant circulating in the refrigerant cycle, and can prevent unnecessary refrigerant use.

On the other hand, the environment of the air conditioning space can be changed at any time. That is, a change in the number of occupants of the air conditioning space and a sudden change in the temperature of the air conditioning space due to inflow of external air may occur over time.

Accordingly, after a certain period of time has elapsed in a state in which the opening degree of the expansion valve 300 is controlled to the minimum opening degree (ie, the first level), the change in the environment of the air conditioning space needs to be sensed again.

The control unit C controls the number of occupants detected again by the human body detecting device 710 (hereinafter, referred to as “second The degree of opening of the expansion valve 300 may be controlled based on a comparison result between the number of occupants”) and the number of first occupants sensed immediately before.

That is, after the predetermined time has elapsed, the number of occupants of the air conditioning space may be detected again by the human body detecting device 710 and transmitted to the control unit C. Here, the predetermined time may be 1 minute to 10 minutes.

On the other hand, when a predetermined time elapses with the minimum opening degree of the expansion valve 300 , a difference may occur between the temperature of the air conditioning space and the set temperature. Therefore, it is necessary to adjust the opening degree of the expansion valve 300 based on the number of occupants again.

Specifically, when the number of first occupants and the number of second occupants are the same, the controller C controls the opening degree of the expansion valve 300 to an N-1 th level that is one step lower than the N th level applied at the initial stage of operation of the air conditioner. can be adjusted. For example, when the expansion valve 300 is controlled to the third level at the initial stage of operation and the number of first occupants and the number of second occupants are the same after the lapse of the predetermined time, the opening degree of the expansion valve 300 is the second level can be adjusted again.

That is, it is highly likely that the difference between the temperature of the air conditioning space and the set temperature after a certain time has elapsed than the difference between the temperature of the air conditioning space and the set temperature eye at the initial stage of driving the air conditioner. In this case, even if the opening degree of the expansion valve is adjusted to the N-1 level, which is one step lower than the N-th level opening degree applied in response to the number of occupants at the initial stage of operation of the air conditioner, the temperature of the air conditioning space can be brought to the set temperature within a sufficiently fast time. In addition to being able to close, the amount of refrigerant circulating in the refrigerant cycle can be minimized.

Alternatively, it can be assumed that a change occurs in the number of occupants after the lapse of the predetermined time. That is, when the number of first occupants is different from the number of second occupants, the opening degree of the expansion valve may be adjusted to an opening degree one level lower than the opening degree stored in the memory M with a value corresponding to the second number of occupants.

Even in this case, the opening degree of the expansion valve 300 is controlled to a level lower than the level according to the number of occupants stored in the memory M, which is the same as the case in which the number of occupants is not changed. However, since the number of first occupants is different from the number of second occupants, the reference level may be the level based on the second occupant number.

For example, when the number of first occupants is 3 and the number of second occupants is 4, the Nth level may be the fourth level. In addition, the opening degree of the expansion valve 300 may be controlled to a third level (ie, N-1 th level) one step lower than the fourth level stored in the memory M in response to the second number of occupants.

As a result, the control unit C may adjust the opening degree of the expansion valve 300 to an opening degree one level lower than the opening degree stored in the memory M in response to the number of occupants detected after the predetermined time has elapsed.

Meanwhile, another change may occur in the environment in the air conditioning space due to disturbances other than the occupants (eg, the use of heat generating products or the inflow of external air due to the opening of a window). It is preferable to control the expansion valve 300 so that the optimum amount of refrigerant circulates the refrigerant cycle even when the environment of the air conditioning space changes.

The control unit C resets the opening degree of the expansion valve 300 based on the first temperature difference between the initial temperature and the set temperature of the air conditioning space and the second temperature difference between the temperature of the air conditioning space and the set temperature after the lapse of the predetermined time. can be adjusted

In general, the first temperature difference may be greater than the second temperature difference. In this case, the opening degree of the expansion valve 300 does not need to be adjusted differently from before. Accordingly, the opening degree of the expansion valve 300 may be controlled to the previous N-1 th level.

That is, when the first temperature difference is greater than the second temperature difference, the control unit C may maintain the opening degree of the expansion valve 300 at an N-1th opening degree.

Alternatively, the first temperature difference may be less than or equal to the second temperature difference. In this case, it can be assumed that disturbance has occurred in the air conditioning space. In this case, the controller C may adjust the opening degree of the expansion valve 300 to the N+1th level.

As described above, when the second temperature difference becomes greater than or equal to the first temperature difference due to the occurrence of disturbance, the controller C controls the opening degree of the expansion valve 300 to compensate for the temperature effect of the air conditioning space caused by the disturbance. It can be controlled at N+1 level.

for example. When the opening degree of the expansion valve 300, which was initially controlled at the third level, is adjusted to the second level because there is no change in the number of occupants, if the second temperature difference is greater than or equal to the first temperature difference, it can be adjusted to the fourth level again. have.

Through the above control, the temperature of the air conditioning space may gradually reach the set temperature again. When the temperature of the air conditioning space reaches the set temperature again and the opening degree of the expansion valve 300 is greater than the minimum opening degree, the controller C sets the opening degree of the expansion valve 300 again to the first level, which is the minimum opening degree. can be controlled with

As described above, by controlling the opening degree of the expansion valve 300 to the minimum opening degree when the temperature of the air conditioning space reaches the set temperature, the amount of refrigerant circulating in the refrigerant cycle can be minimized as much as possible, and refrigerant loss can be minimized, and energy can save

Hereinafter, a method for controlling an air conditioner according to an embodiment of the present invention will be described with reference to other drawings.

3 is a flowchart illustrating a method for controlling an air conditioner according to an embodiment of the present invention. In describing the control method of the air conditioner with reference to FIG. 3 , it is obvious that the above-described characteristics of the air conditioner can be equally applied to the control method of the air conditioner.

3, the control method of the air conditioner according to the embodiment of the present invention includes a driving start step (S100), a first occupant count detection step (S200), an initial control step of the expansion valve 300 (S300), It may include a determination step (S400) of reaching the set temperature, and a control step (S500) of the minimum opening degree of the expansion valve 300 .

In the driving start step ( S100 ), the driving of the air conditioner may be started based on the set temperature input by the user.

In the first occupant number detection step ( S200 ), the number of occupants of the air conditioning space may be detected by the human body sensor 710 . The air-conditioning space mentioned below may mean one air-conditioning space identical to the above-mentioned air-conditioning space.

In the initial control step ( S300 ), the opening degree of the expansion valve 300 may be controlled to an N-th level corresponding to the number of first occupants among a plurality of preset levels. That is, the number of occupants of the air conditioning space detected in the first occupant number sensing step S200 may be defined as the first occupant number. In addition, in the initial control step ( S300 ), the opening degree of the expansion valve 300 may be adjusted to the N-th level stored in advance in the memory M in response to the first number of occupants. For example, when the first number of occupants is three, the opening degree of the expansion valve 300 may be adjusted to a third level (eg, an opening degree of 50%).

It may further include a determination step (S400) of reaching the set temperature, and the expansion valve 300 may be maintained at the opening adjusted in the initial control step (S300) until the temperature of the air conditioning space reaches the set temperature.

When the temperature of the air conditioning space reaches the set temperature, the opening degree of the expansion valve 300 may be controlled to the minimum opening degree in the minimum opening degree control step ( S500 ). In this case, the level corresponding to the minimum opening degree may be a first level (eg, an opening degree of 10%).

Through the minimum opening degree control step (S500), it is possible to maintain the temperature of the air conditioning space near the set temperature by using the minimum amount of refrigerant.

Meanwhile, after the minimum opening degree control step S500 is maintained for a predetermined time (eg, 1 to 10 minutes), the opening degree control of the expansion valve 300 corresponding to the environmental change of the air conditioning space may be performed.

Therefore, it is necessary to detect the number of occupants of the air conditioning space again and compare it with the initially detected number of occupants.

FIG. 4 is a flow chart embodying some steps (first opening degree adjustment step) of FIG. 3 . Hereinafter, it will be described with reference to FIG. 4 together.

The control method of the air conditioner according to the present invention includes a second occupant number detection step (S600) and the first occupant number detection step (S600) in which the number of occupants is detected again by the human body sensor 710 after a predetermined time has elapsed from the minimum opening degree control step (S500). The method may further include a first opening degree adjusting step ( S700 ) in which the opening degree of the expansion valve 300 is controlled to the N-1 th level based on the comparison result of the number of first occupants and the second occupants.

That is, while the minimum opening degree control step ( S500 ) is maintained, the temperature of the air conditioning space may slightly deviate from the set temperature. However, the difference between the temperature of the air conditioning space and the set temperature during the minimum opening degree control step S500 may be smaller than the difference between the temperature of the air conditioning space and the set temperature at the initial stage of driving the air conditioner.

Accordingly, when the number of occupants does not change, it is sufficient if the opening degree of the expansion valve 300 is controlled to the N-1th level, which is one step lower than the Nth level in the initial control step ( S300 ). For example, when the opening degree of the expansion valve 300 is adjusted to the third level in the initial control step S300 and there is no change in the number of occupants, the opening degree of the expansion valve 300 in the first opening degree adjusting step S700 may be controlled to the second level.

In addition, when there is a change in the number of occupants, it is sufficient if the opening degree of the expansion valve 300 is controlled to a level lower than the level stored in the memory M in response to the changed number of occupants. For example, when the opening degree of the expansion valve 300 is adjusted to the third level in the initial control step S300 and the number of occupants is increased by one, the Nth level may be a fourth level corresponding to the number of four occupants. . Accordingly, the opening degree of the expansion valve 300 in the first opening degree adjusting step (S700) may be controlled to the third level, which is the N-1th level.

As described above, in the first opening degree adjustment step (S700), the first occupant number and the second occupant number are compared (S710), and when the first occupant number and the second occupant number are the same, the expansion valve 300 It may include a step (S750) of adjusting the opening degree of the N-1 th level.

That is, when the number of first occupants and the number of second occupants are the same, the amount of refrigerant circulating in the refrigerant cycle can be reduced by adjusting the opening degree of the expansion valve 300 to the N-1th level, which is one step lower than the preset Nth level. .

Also, in the first opening degree adjusting step (S700), if the number of first occupants is different from the number of second occupants, the N-th level is changed to the N-th level to correspond to the second number of occupants (S730) The step of adjusting the opening degree of the expansion valve 300 to the N-1th level (S750) may be further included.

For example, if the first number of occupants is 3 and the second number of occupants is 4, then the Nth level corresponding to 3 people (ie, the third level) is the N'th level corresponding to 4 people (ie, the fourth level) ) may be changed to (S730). And, the opening degree of the expansion valve 300 may be controlled to the N-1th level (ie, the third level) (S750).

On the other hand, when a disturbance such as disposition of a heating material or opening of a window occurs in the air conditioning space, it is necessary to adjust the opening degree of the expansion valve 300 again so that the temperature of the air conditioning space follows the set temperature.

In the control method of the air conditioner according to the present invention, after the first opening degree adjusting step (S700), the second opening degree adjusting step (S800) in which the opening degree of the expansion valve 300 is adjusted again based on the temperature of the air conditioning space and the set temperature ) may be further included.

FIG. 5 is a flow chart embodying some other steps (second opening degree adjustment step) of FIG. 3 . Hereinafter, it will be described with reference to FIG. 5 .

The second opening degree control step (S800) is a temperature difference comparison step (S810) in which the first temperature difference between the initial temperature and the set temperature of the air conditioning space and the second temperature difference between the temperature of the air conditioning space and the set temperature after the lapse of the predetermined time are compared (S810) and adjusting the opening degree of the expansion valve 300 based on the comparison result in the temperature difference comparison step (S810) (S830 and S850).

The initial temperature may be the temperature of the air conditioning space sensed in the driving start step (S100). In addition, the set temperature input by the user may be constantly maintained.

Accordingly, in a general case where the disturbance does not occur in the air conditioning space, the first temperature difference may be greater than the second temperature difference. In this case, the opening degree of the expansion valve 300 may be maintained at the N-1 th level described above (S850).

Alternatively, when the disturbance occurs in the air conditioning space, the first temperature difference may be less than or equal to the second temperature difference. That is, when disturbance occurs in the air conditioning space, the second temperature difference may be greater than or equal to the first temperature difference.

In this case, the opening degree of the expansion valve 300 may be adjusted to the N+1th level in order to compensate for the temperature change of the air conditioning space due to disturbance and to allow the temperature of the air conditioning space to quickly reach the set temperature (S830). . For example, in the first opening degree adjusting step (S700), the opening degree of the expansion valve 300 is adjusted to the third level, which is the N-1th level, and in the second opening degree adjusting step (S800), the first temperature difference is the When it is determined to be less than or equal to the second temperature difference, the opening degree of the expansion valve 300 may be adjusted to a fifth level, which is an N+1th level.

As described above, according to the present invention, it is possible to circulate the refrigerant cycle with the minimum amount of refrigerant possible in response to changes in the environment of the air conditioning space such as fluctuations in the number of occupants and disturbances.

In the control method of the air conditioner according to the present invention, after the second opening degree adjusting step (S800), the step of determining whether the temperature of the air conditioning space has reached the set temperature again (S900), the temperature of the air conditioning space is the set temperature The method may further include a step (S930) of determining whether the opening degree of the expansion valve 300 is the minimum opening degree when reached.

When it is determined that the minimum opening degree of the expansion valve 300 is not the minimum opening degree, the above-described minimum opening degree control step S500 to second opening degree adjustment step S800 may be repeatedly performed.

Alternatively, when it is determined that the minimum opening degree of the expansion valve 300 is the minimum opening degree, the opening degree of the expansion valve 300 may be maintained at the minimum opening degree.

The preferred embodiments of the present invention described above are disclosed for the purpose of illustration, and various modifications, changes, and additions may be made by those skilled in the art having ordinary knowledge of the present invention within the spirit and scope of the present invention, and such modifications, changes and additions shall be deemed to fall within the scope of the following claims.

100 Compressor 200 Indoor Heat Exchanger
210 Indoor fan 300 Expansion valve
400 Outdoor Heat Exchanger 410 Outdoor Fan
500 Accumulator 600 Euro Switching Valve
710 Human body detection device 720 Temperature sensor

Claims (15)

An air conditioner comprising: an outdoor unit having a compressor and an outdoor heat exchanger; and an indoor unit having an expansion valve and an indoor heat exchanger;
a human body detecting device configured to detect the number of occupants in the air conditioning space;
a memory for storing information on opening degree of a plurality of (N) levels of the expansion valve corresponding to the number of occupants, and setting the level as a ratio to the maximum degree of opening; and
A control unit electrically connected to the human body sensing device and the memory, and controlling the expansion valve,
stored in the memory so that the value of the opening degree of the expansion valve corresponds to the number of occupants;
the control unit controls the opening degree of the expansion valve based on the number of first occupants detected at the initial stage of driving the air conditioner and the corresponding opening degree information;
increasing or decreasing the opening degree of the expansion valve based on a comparison result between the second number of occupants sensed again by the human body detection device and the first occupant number detected immediately after a predetermined time elapses;
increasing or decreasing the opening degree of the expansion valve by comparing the first temperature difference between the initial temperature of the air conditioning space and the set temperature and the second temperature difference between the temperature of the air conditioning space and the set temperature after the lapse of the predetermined time;
An air conditioner, characterized in that when the temperature of the air conditioning space reaches a set temperature, the opening degree of the expansion valve is controlled to the minimum opening degree. According to claim 1,
and the controller controls the opening degree of the expansion valve to a first level, which is a minimum opening degree, when the temperature of the air conditioning space reaches a set temperature. delete According to claim 1,
When the number of the first occupants is the same as the number of the second occupants,
The control unit controls the opening degree of the expansion valve to an N-1 th level. According to claim 1,
When the number of the first occupants is different from the number of the second occupants,
and the control unit controls the expansion valve to an opening degree one level lower than the opening degree of the expansion valve stored in the memory in response to the second number of occupants. delete According to claim 1,
The control unit maintains the opening degree of the expansion valve at an N-1 th level when the first temperature difference is greater than the second temperature difference. According to claim 1,
The control unit controls the opening degree of the expansion valve to an N+1th level when the first temperature difference is less than or equal to the second temperature difference. 8. The method of claim 7,
When the temperature of the air conditioning space reaches the set temperature again and the opening degree of the expansion valve is greater than the minimum opening degree, the control unit controls the opening degree of the expansion valve back to the first level, which is the minimum opening degree. . a first occupant number detection step of detecting the number of occupants by a human body detection sensor;
an initial control step in which an opening degree of the expansion valve is controlled to an N-th level corresponding to a first number of occupants among a plurality of preset levels;
a minimum opening degree control step of controlling the expansion valve to a minimum opening degree when the temperature of the air conditioning space reaches a set temperature;
a second occupant number detection step in which the number of occupants is detected again by a human body sensor after a predetermined period of time has elapsed from the minimum opening degree control step;
a first opening degree adjusting step of controlling an opening degree of the expansion valve to an N-1th level based on a result of comparing the first number of occupants and the second number of occupants; and
After the first opening degree control step, the first temperature difference between the initial temperature and the set temperature of the air conditioning space and the second temperature difference between the temperature and the set temperature of the air conditioning space after the lapse of the predetermined time are compared, and in the temperature difference comparison step, the and a second opening degree adjusting step in which the opening degree of the expansion valve is changed to an N+1th opening degree when the first temperature difference is less than or equal to the second temperature difference,
After the second opening degree adjusting step, when the temperature of the air conditioning space reaches a set temperature, the opening degree of the expansion valve is changed to the minimum opening degree or maintained at the minimum opening degree. 11. The method of claim 10,
The first opening degree control step is,
a occupant number comparison step of comparing the first occupant number with the second occupant number; and
and adjusting the opening degree of the expansion valve to an N-1 th level when the number of first occupants and the number of second occupants are the same in the step of comparing the number of occupants. 12. The method of claim 11,
The first opening degree control step is,
The method further comprising the step of changing the N-th level to correspond to the second number of occupants when the number of first occupants is different from the number of second occupants in the step of comparing the number of occupants;
The control method of the air conditioner, characterized in that the opening degree of the expansion valve is adjusted to the N-1th level. delete delete delete

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