KR101235546B1 - An air conditioner and a control method the same - Google Patents

Abstract

PURPOSE: A method for controlling an air conditioner is provided to save electricity by preventing the overshooting of a compressor, and to elastically control the frequency of the compressor by coping with adjustable target pressure. CONSTITUTION: A method for controlling an air conditioner comprises following steps. A compressor is operated with a first frequency according to a cooling cycle(S14). Condensation pressure is set as first pressure on the basis of the initial operation of the compressor. The elapsed time after the initial operation of the compressor is integrated. A rate value between the initial set temperature difference and the current set temperature difference is recognized(S18). The operation frequency of the compressor is changed into a second frequency by comparing the rate value to a set value(S19). If the rate value is higher than the set value, the compressor is controlled with the second frequency higher than the first frequency. If the rate value is higher than the set value, the compressor is controlled with second pressure higher than the first pressure. [Reference numerals] (AA) Start; (BB) End; (S11) Air conditioner ON; (S12) Inputting a set temperature of an air conditioning space and starting an operation; (S13) Initializing a compressor; (S14) Setting a compressor operation frequency(first frequency) according to an indoor set temperature difference and outdoor air temperature; (S15) Determining a target high pressure; (S16) Integrating the time after initialization of the compressor; (S17) Set time has passed?; (S18) Recognizing a ratio between the initial set temperature difference and the current set temperature difference; (S19) Determining whether to change the operation frequency according to comparison between the ratio and a set value; (S20) Ratio is equal to the set value?; (S21) Maintaining the compressor operation frequency; (S22) Maximum set time has passed?; (S23) Reaching a set indoor temperature; (S24) Ratio > Set value ?; (S25) Changing to a second frequency(> the first frequency); (S26) Changing to a second frequency(< the first frequency)

Description

An air conditioner and a control method the same}

The present invention relates to a control method of an air conditioner.

The air conditioner is an appliance for keeping the indoor air in the most suitable condition according to the purpose and purpose. For example, in the summer, the room is controlled by a cool air condition, while in winter the room is controlled by a warm heating condition, by the humidity of the room, and by the clean air of the room.

In detail, the air conditioner is driven by a refrigeration cycle that performs the compression, condensation, expansion and evaporation process of the refrigerant, thereby performing the cooling or heating operation of the indoor space. Elements constituting the refrigeration cycle include a compressor, a condenser, an expansion device and an evaporator.

Such an air conditioner may be classified into a separate type air conditioner that separates the indoor unit and the outdoor unit, and an integrated air conditioner that combines the indoor unit and the outdoor unit into one device, depending on whether the indoor unit and the outdoor unit are separated.

The outdoor unit includes an outdoor heat exchanger that exchanges heat with outside air, and the indoor unit includes an indoor heat exchanger that exchanges heat with indoor air. The air conditioner may be operated switchable to the cooling mode or the heating mode.

When the air conditioner is operated in a cooling mode, the outdoor heat exchanger functions as a condenser and the indoor heat exchanger functions as an evaporator. On the other hand, when the air conditioner is operated in the heating mode, the outdoor heat exchanger functions as an evaporator and the indoor heat exchanger functions as a condenser.

On the other hand, the target high pressure, that is, the condensation pressure of the refrigeration cycle is set while the air conditioner is turned on and the compressor is initially started, and the refrigeration cycle is operated according to the set condensation pressure.

Referring to FIG. 4, in the conventional air conditioner, when the power of the air conditioner is turned on and a specific operating condition is input, the operating frequency of the compressor is changed according to the indoor temperature and the outdoor temperature, and the set temperature recognized by the air conditioner. Are set (S1, S2, S3).

Then, the target high pressure corresponding to the set operating frequency is determined, and the refrigeration cycle by the determined target high pressure is operated (S4, S5).

According to the conventional air conditioner control method, since the target high pressure determined at the initial start of the compressor does not change, there is a problem that an operating condition (target high pressure) is not formed in response to the load in the room.

In other words, during the operation of the air conditioner after the initial startup of the compressor, the refrigeration cycle is operated depending on the target high pressure determined in the indoor environment conditions, that is, the value of the room set temperature and room temperature are not reflected at all. .

In this situation, when the air conditioner matches a narrow indoor space, the compressor is overshooted to meet the determined target high pressure, even though the room temperature can be quickly reached. There was a problem causing unnecessary power consumption.

On the contrary, in the case where the air conditioner matches a large indoor space, the compressor is undershooted to meet only the determined target high pressure, even though the room temperature is late at the set temperature, so that the user can quickly reach the desired room temperature. The problem of missing was caused.

The present invention has been proposed to solve such a problem, and an object of the present invention is to provide a control method of an air conditioner in which operation can be controlled in response to an indoor load condition.

In the control method of the air conditioner according to an embodiment of the present invention, a method for controlling an air conditioner that is driven according to a set refrigeration cycle, and operates so that the temperature of the conditioning space reaches a set temperature, the compressor according to the refrigeration cycle Is initially started and operated at a first frequency; In accordance with an initial startup of the compressor, forming a condensation pressure at a first pressure; Integrating an elapsed time since the compressor was initially started; Recognizing a ratio value between the initial set temperature difference and the current set temperature difference at the set elapsed time; And comparing the ratio value with the set value, and changing an operating frequency of the compressor to a second frequency.

According to the present invention, even if the target high pressure is determined at the initial start of the compressor, since the target high pressure can be adjusted in response to the indoor load thereafter, the set temperature can be reached within the set time regardless of the size of the harmonic space. There is.

In addition, it is possible to flexibly control the frequency of the compressor in response to the target high pressure to be adjusted, thereby preventing the overshooting of the compressor has the advantage of reducing unnecessary power consumption.

In addition, by preventing the undershooting of the compressor has the effect that the user can quickly reach the desired room temperature.

In addition, since the indoor temperature can be adjusted to the set temperature within a predetermined time, there is an advantage that can provide a comfortable indoor space to the user to ensure the reliability (satisfaction) for the product.

1 is a block diagram showing the configuration of an air conditioner according to an embodiment of the present invention.
2 is a flowchart illustrating a method of controlling an air conditioner according to an embodiment of the present invention.
3 is a graph showing a set value trend with respect to a ratio of an initial set temperature difference and a current set temperature difference in the control method of the air conditioner according to the embodiment of the present invention.
4 is a flow chart showing a control method of the air conditioner according to the prior art.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. It is to be understood, however, that the spirit of the invention is not limited to the embodiments shown and that those skilled in the art, upon reading and understanding the spirit of the invention, may easily suggest other embodiments within the scope of the same concept.

1 is a block diagram showing the configuration of an air conditioner according to an embodiment of the present invention, Figure 3 is a control method of the air conditioner according to an embodiment of the present invention, in the ratio of the initial set temperature difference and the current set temperature difference This graph shows the trend of the set value.

1 and 3, the air conditioner 1 according to the embodiment of the present invention is driven according to the refrigeration cycle, so that the temperature of the harmonic space reaches the set temperature. The air conditioner 1 includes a compressor for compressing a refrigerant, and by controlling the operating frequency of the compressor, the outlet pressure of the compressor or the inlet pressure of the condenser can be adjusted.

The outlet pressure of the compressor or the inlet pressure of the condenser is called "high pressure", and the high pressure to be reached as a control target on the refrigeration cycle is called "target high pressure".

The air conditioner 1 includes an input unit 10 for inputting a condition or a specific command related to the operation of the air conditioner 1, an indoor temperature sensor 20 for sensing a temperature of an indoor space to be air-conditioned, Ambient temperature sensor 30 for sensing the ambient temperature, a timer 40 for integrating elapsed time after a specific time point, and a memory unit 50 for storing predetermined information necessary for controlling the operation of the air conditioner 1. And a control unit 70 receiving information from these components and generating a control signal, and a compressor 60 driven according to the control signal of the control unit 70.

The input unit 10 includes an input unit for inputting a set temperature value of the harmonic space (indoor space). For example, a user may input a specific set temperature value or a preset temperature value may be automatically input.

The temperature value detected by the room temperature sensor 20 and the outside air temperature sensor 30 may be transmitted to the controller 70 periodically or aperiodically.

The timer 40 may accumulate the time elapsed since the air conditioner 1 is turned on and the compressor 60 is initially started. That is, the elapsed time since the time when the compressor 60 starts to be driven may be accumulated.

The memory unit 50 includes a difference between a room temperature and a set temperature (hereinafter, referred to as an “initial set temperature difference”) at the time when the compressor 60 is initially started and a room detected after a predetermined time has elapsed. Information about the ratio of the difference between the temperature and the set temperature (hereinafter, referred to as “current set temperature difference”) may be stored.

Referring to FIG. 3, the X-axis value defines an elapsed time value, and the Y-axis value defines a target value K with respect to the ratio of the current set temperature difference to the initial set temperature difference. That is, the K value is the current set temperature difference / initial set temperature difference.

In the X-axis value, "0" means the time when the compressor 60 is initially started, and the last time value (end value, 600 seconds in the figure) at which the K value becomes 0 sets the temperature of the indoor space. It means the target time value to adjust the temperature.

That is, the air conditioner 1 aims to adjust the temperature of the indoor space to the set temperature within 600 seconds. However, the 600 seconds is a value arbitrarily set for the control of the air conditioner, it may be set to a different value.

K (Y-axis value) of Figure 3 is determined by the following function.

(t: Elapsed time after initial compressor start (X-axis value), t _s : Target time to reach set temperature)

Here, the t _s value is understood as a value corresponding to 600 seconds described above. And, as shown in Figure 3, it can be seen that the K value decreases nonlinearly with time.

In summary, an object of the present invention is to maintain the K value at 0 at the time ts has elapsed by controlling the frequency of the compressor and controlling the target high pressure after the compressor is initially started.

When the room temperature reaches the set temperature, it is possible to sufficiently assume that the K value may be 0 according to the definition of the K value (set temperature difference / initial set temperature difference).

Meanwhile, the K value is used as reference information for adjusting the target high pressure in the process of driving the compressor 60, that is, controlling the frequency of the compressor 60.

In detail, when the compressor 60 is initially started, the operating frequency is determined so that the target high pressure is formed in response to the indoor and outdoor temperatures and the set temperature. The target high pressure formed at this time may be a minimum pressure that can be set. The operating frequency at the initial start of the compressor is called "first frequency".

In a state where a predetermined time has elapsed since the initial startup of the compressor 60, when the K value is larger than the actual ratio value, that is, the ratio value of the current set temperature difference to the actual initial set temperature difference, the frequency of the compressor 60 ( Hz) to increase the target high pressure. In this case, the cooling and heating ability is increased, and the speed at which the room temperature converges to the set temperature is increased.

On the other hand, when the K value is smaller than the actual ratio value, the target high pressure may be lowered by lowering the frequency of the compressor 60. In this case, the cooling and heating ability can be reduced, and the speed at which the room temperature converges to the set temperature can be reduced.

The frequency that is changed (raised or lowered) after the initial startup of the compressor 60 is called "second frequency". In the process of driving the compressor 60, the second frequency may be increased or decreased depending on the result of comparing the K value with the actual ratio value, and this increase or decrease may be repeated.

On the other hand, the time point at which the K value is compared with the actual ratio value may be selected (set) periodically or according to a set period or aperiodic based on an indoor / outdoor temperature value.

As such, in a process of operating the air conditioner, when a predetermined time elapses, a ratio value between the initial set temperature difference and the current set temperature difference is recognized, and the frequency of the compressor is changed by comparing the ratio value with the set value (K value). Therefore, it is possible to control the compressor corresponding to the indoor load.

2 is a flowchart illustrating a method of controlling an air conditioner according to an embodiment of the present invention. 2, a control method of an air conditioner according to an embodiment of the present invention will be described.

The air conditioner 1 is turned on, and operation conditions related to the operation of the air conditioner 1 are input. The operating condition may include a set temperature of the harmonic space. When the operation condition is input and the start command is recognized, the operation of the air conditioner is started, and the compressor 60 is initially started (S11, S12, S13).

The temperature and the set temperature of the indoor and outdoor space can be detected, the operating frequency (first frequency) of the compressor is set according to the difference between the indoor temperature and the set temperature, the outside temperature, and the target high pressure (condensation pressure) can be determined. . Here, the target high pressure is called the first pressure (S14, S15).

The time elapsed since the compressor 60 was initially started is accumulated. Then, it is recognized whether or not the set time has elapsed. As described above, the set time may be set periodically or may be set aperiodically according to indoor and outdoor temperature information (S17).

When the set time has elapsed, a ratio value between the initial set temperature difference and the current set temperature difference is recognized. Then, whether or not to change the operating frequency of the compressor 60 is determined according to the comparison between the ratio value and the set value (K value) (S18, S19).

If the ratio value and the set value are the same, it is recognized that the control is controlled according to the target value of the room temperature compared to the set time, the operating frequency of the compressor will be maintained at the first frequency (S20, S21).

On the other hand, if it is recognized that the ratio value is larger than the set value, the operating frequency of the compressor 60 is changed to the second frequency. Here, the second frequency may form a value larger than the first frequency. Then, the target high pressure is corrected to a second pressure larger than the first pressure (S24, S25).

If it is recognized that the ratio value is smaller than the set value, the operating frequency of the compressor 60 is changed to the second frequency. Here, the second frequency may form a value smaller than the first frequency. Then, the target high pressure is corrected to a second pressure smaller than the first pressure (S26).

Depending on whether the set time has elapsed, the steps of S16 to S26 may be repeated. That is, it is recognized whether the maximum set time (preset time end value, ts) has elapsed, and if the maximum set time has not elapsed, the process returns to step S16.

On the other hand, if the maximum set time has elapsed, it may be recognized that the room temperature has reached the set temperature, and the refrigeration cycle may be operated at the target high pressure and the operating frequency of the compressor at the maximum set time (S22, S23).

According to this control method, the target high pressure can be corrected by controlling the operating frequency of the compressor by comparing the ratio value of the actual temperature difference and the set ratio value in the process of driving the compressor.

As a result, since the room temperature can reach the set temperature within the maximum set time, it has a constant operating performance regardless of the size of the space can be improved reliability of the product.

1: air conditioner 10: input unit
20: room temperature sensor 30: outside temperature sensor
40: timer 50: memory
60: compressor 70: control unit

Claims (11)

A method of controlling an air conditioner, which is driven according to a set refrigeration cycle and is operated so that the temperature of a harmonic space reaches a set temperature,
A compressor is initially started and operated at a first frequency according to the refrigeration cycle;
In accordance with an initial startup of the compressor, forming a condensation pressure at a first pressure;
Integrating an elapsed time since the compressor was initially started;
Recognizing a ratio value between the initial set temperature difference and the current set temperature difference at the set elapsed time; And
Comparing the ratio value with a set value, and changing the operation frequency of the compressor to a second frequency. The method of claim 1,
In the step of changing the operating frequency of the compressor to the second frequency,
And controlling the condensation pressure to a second pressure greater than or less than the first pressure. The method of claim 2,
And if the ratio value is greater than the set value, the compressor is controlled such that the second frequency is made larger than the first frequency. The method of claim 2,
And if the ratio value is greater than the set value, the compressor is controlled such that the second pressure is formed higher than the first pressure. The method of claim 2,
And if the ratio value is smaller than the set value, the compressor is controlled such that the second frequency is formed smaller than the first frequency. The method of claim 2,
And if the ratio value is smaller than the set value, the compressor is controlled such that the second pressure is made larger than the first pressure. The method of claim 1,
The initial set temperature difference is the difference between the set temperature and the temperature of the harmonic space during the initial startup of the compressor,
And the current set temperature difference is a temperature difference between the set temperature and the set space at the set elapsed time. The method of claim 1,
In the set elapsed time,
A control method of an air conditioner including a plurality of elapsed time selected aperiodically based on a predetermined cycle or indoor and outdoor temperature. The method of claim 1,
The set value is a value
The control method of the air conditioner which is a function value regarding the said set elapsed time t and the maximum set elapsed time ts. The method of claim 9,
And the set value becomes nonlinearly smaller as the set elapsed time increases. The method of claim 9,
When the set elapsed time reaches the maximum set elapsed time,
And the temperature of the harmonic space reaches the set temperature.

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