KR102008928B1 - A method for controlling an air conditioner - Google Patents

Abstract

The control method of the air conditioner of this invention is related. In the control method of the air conditioner according to the spirit of the present invention, in the control method of the air conditioner including an outdoor unit having a compressor, an outdoor heat exchanger and a main expansion device, the outdoor heat exchanger functions as an evaporator, Measure the discharge temperature of the refrigerant discharged from the controller and store the change amount (first information), measure the discharge temperature and the temperature of the refrigerant flowing into the compressor, and store the difference (second information), Measure and store the outside temperature (third information), and store the change in the opening degree (fourth information) of the main expansion device, so that the first to third information is in the respective predetermined numerical values (B, C, D) ranges. If the fourth information is smaller than zero, the control enters the limit control for limiting the amount of change in the opening degree of the main expansion device.

Description

Control method of air conditioner {A METHOD FOR CONTROLLING AN AIR CONDITIONER}

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

In general, an air conditioner refers to a device that controls an indoor temperature to create a comfortable indoor air environment.

Such an air conditioner includes an indoor unit installed indoors and an outdoor unit supplying a refrigerant to the indoor unit. At least one indoor unit may be connected to the outdoor unit. In addition, the outdoor unit may be provided with a compressor, an outdoor heat exchanger, and a main expansion device.

The air conditioner may be operated by cooling or heating operation by supplying a refrigerant to the indoor unit. Here, the cooling operation or the heating operation, which is an operation method of the air conditioner, is determined according to the flow of the circulating refrigerant. That is, the air conditioner may operate in a cooling operation or a heating operation depending on the flow of the refrigerant.

First, the flow of the refrigerant will be described when the air conditioner operates in a cooling operation. The refrigerant compressed by the compressor of the outdoor unit becomes a liquid refrigerant of medium temperature and high pressure through an outdoor heat exchanger functioning as a condenser. When the liquid refrigerant is supplied to the indoor unit, vaporization may occur as the refrigerant is expanded in the indoor heat exchanger functioning as an evaporator. The temperature of the ambient air of the indoor heat exchanger is lowered by the vaporization phenomenon. When the indoor unit fan rotates, ambient air of the heat exchanger of the indoor unit whose temperature is lowered is discharged to the room.

Next, when the air conditioner operates in a heating operation, the flow of the refrigerant is as follows. When the high temperature and high pressure gas refrigerant is supplied to the indoor unit from the compressor of the outdoor unit, the high temperature and high pressure gas refrigerant may be liquefied in the indoor heat exchanger that functions as a condenser. The energy released by the liquefaction phenomenon raises the temperature of the ambient air of the indoor heat exchanger. Then, when the indoor unit fan is rotated, the ambient air of the indoor heat exchanger whose temperature is raised may be discharged to the room. The liquefied refrigerant may be expanded by the main expansion device and then introduced into the outdoor heat exchanger functioning as an evaporator to be vaporized.

On the other hand, when the air conditioner performs a heating operation, if the outside temperature (outdoor temperature) of the outdoor unit is too low, a cycle hunting phenomenon may occur. In particular, in the case of using R32, which is attracting attention as an environmentally friendly refrigerant, the cycle hunting phenomenon is very likely to occur since the pressure is rapidly increased compared to other refrigerants.

Hereinafter, with reference to the drawings will be described in detail.

1 is a view showing a change in the discharge temperature and the like according to the conventional air conditioner control method. In detail, FIG. 1 is a view showing the discharge temperature and the frequency change of the compressor according to the driving time of the air conditioner, and the opening amount of the main expansion device (EEV).

In Fig. 1, section a corresponds to start control (start-up operation) and section b corresponds to timing control (general operation). At this time, despite the increase in the discharge temperature of the compressor in section c, the opening amount of the main expansion device continues to decrease to reduce the amount of refrigerant. As a result, the discharge temperature rises rapidly, and emergency control is performed in section d.

At this time, although the emergency control is performed to quickly increase the opening amount of the main expansion device, the discharge temperature continues to rise. Accordingly, the frequency of the compressor is drastically lowered and cycle hunting may occur. In addition, it can be seen that the discharge temperature is continuously changed even in the e section in which the discharge temperature is lowered and is unstable.

That is, the conventional control has a problem that the stable control according to the characteristics of the R32 is impossible. In addition, there is a problem that the efficiency of the air conditioner is very low as the unstable state continues.

An object of the present invention has been proposed to solve this problem, and to provide a control method of an air conditioner optimized according to the characteristics of R32.

Another object of the present invention is to provide a control method of an air conditioner which prevents a sudden rise in discharge temperature and maintains a stable state.

In the control method of the air conditioner according to the spirit of the present invention, in the control method of the air conditioner including an outdoor unit having a compressor, an outdoor heat exchanger and a main expansion device, the outdoor heat exchanger functions as an evaporator, Measure the discharge temperature of the refrigerant discharged from the controller and store the change amount (first information), measure the discharge temperature and the temperature of the refrigerant flowing into the compressor, and store the difference (second information), Measure and store the outside temperature (third information), and store the change in the opening degree (fourth information) of the main expansion device, so that the first to third information is in the respective predetermined numerical values (B, C, D) ranges. If the fourth information is smaller than zero, the control enters the limit control for limiting the amount of change in the opening degree of the main expansion device.

The first information is greater than or equal to the B value (first entry condition), the second information is greater than or equal to the C value (second entry condition), the third information is less than or equal to the D value (third entry condition), and the first If 4 information is less than 0 (fourth entry condition), it may enter into the limit control.

When the restriction control is performed, the restriction control may be released when at least one of the first to third pieces of information falls within a predetermined range of numerical values (E, F, G) or when the fourth information is zero or more. .

When performing the restriction control, the first information is equal to or less than the E value (first release condition), the second information is less than the F value (second release condition), or the third information is equal to or greater than the G value (third) Release condition), when the fourth information is equal to or greater than zero (fourth release condition), the restriction control may be released.

By measuring the discharge temperature of the refrigerant discharged from the compressor, when the discharge temperature is equal to or greater than the A value, it may be entered into the emergency control.

When the emergency control is performed, the opening degree of the main expansion device is increased by J value at predetermined time intervals, and the emergency control may be released when the discharge temperature is less than the A value.

When performing the limit control, when the first information is within a predetermined numerical range, the opening degree of the main expansion device is maintained (the amount of change in opening degree = 0), and when the first information exceeds the H value, the main expansion device The opening degree of can be increased to the I value.

When the first information is greater than or equal to the B value, one condition of entering the limit control is satisfied, and when performing the limit control, when the first information is greater than the E value or less than the H value, the opening degree of the main expansion device is maintained. The B value and the E value may be different from each other.

When performing the limit control, if the first information is equal to or less than the E value, the limit control is released. When the first information is greater than the E value and less than or equal to the H value, the opening degree of the main expansion device is maintained (the amount of change in the opening amount). = 0), when the first information exceeds the H value, the opening degree of the main expansion device may be increased to an I value.

The I value may be +2 pulse.

When the first information is 3 degrees or more, when the condition for entering the limited control is satisfied, and the first information is 1 degree or less when the limiting control is performed, the limiting control may be released.

When the second information is 20 degrees or more, when the condition for entering the limit control is satisfied, and when the limit control is performed, the limit control may be released when the second information is less than 18 degrees.

When the third information is less than 0 degrees, the condition for entering the limit control is satisfied, and when the limit control is performed, when the third information is 2 degrees or more, the limit control may be released.

The refrigerant may be R32.

In the control method of the air conditioner according to the embodiment of the present invention it can be expected the following effects.

According to an embodiment of the present invention, by providing an air conditioner control method optimized for R32 which is an environmentally friendly refrigerant, there is an advantage that R32 can be used more effectively.

In detail, there is an advantage that the cycle operation can be stabilized by preventing the rapid rise of the compressor discharge temperature.

In addition, due to the stable operation of the air conditioner to which the new refrigerant (R32) is applied, there is an advantage that the user's reliability can be secured.

In addition, the use of a new refrigerant (R32), there is an advantage that the price can be reduced to ensure price competitiveness.

In addition, as the cycle is operated stably, there is an advantage that the compressor can be operated for maximum efficiency.

In addition, there is an advantage that it is possible to control in response to a new refrigerant more easily by software control without having a separate device.

1 is a view showing a change in the discharge temperature and the like according to the conventional air conditioner control method.
2 is a diagram illustrating an outdoor unit of an air conditioner according to an embodiment of the present invention.
3 is an exploded view illustrating an outdoor unit of an air conditioner according to an embodiment of the present invention.
4 is a view briefly illustrating a refrigerant flow of an air conditioner according to an embodiment of the present invention.
5 is a view showing a control configuration according to an embodiment of the present invention.
6 and 7 illustrate control flows according to an embodiment of the present invention.
8 is a view showing a change in the discharge temperature and the like according to the air conditioner control method according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, the spirit of the present invention is not limited to the embodiments presented, and those skilled in the art who understand the spirit of the present invention can easily suggest other embodiments within the scope of the same idea.

An air conditioner according to the spirit of the present invention includes an indoor unit installed in an indoor space and an outdoor unit installed in an outdoor space. The indoor unit and the outdoor unit are connected by a refrigerant pipe to form a refrigeration cycle. Hereinafter, for convenience of description, only the outdoor unit is shown.

2 is a view showing the outdoor unit of the air conditioner according to an embodiment of the present invention, Figure 3 is a view showing an exploded view of the outdoor unit of the air conditioner according to an embodiment of the present invention.

2 and 3, the outdoor unit of the air conditioner according to the embodiment of the present invention is provided in the outdoor space to heat exchange with the outdoor air.

The outdoor unit 10 includes a case forming an exterior and containing a plurality of parts. The case includes a front panel 11, a rear panel 12, an upper panel 13, and side panels 14 and 15.

The front panel 11 constitutes a front surface of the outdoor unit 10 and includes a front discharge port 11a through which air is discharged to the outside of the outdoor unit 10.

The rear panel 12 is disposed to be spaced rearward from the front panel 11 to form an internal space of the outdoor unit 10. In addition, the rear panel 12 is provided with a rear suction port 12a through which air is sucked into the outdoor unit 10.

The side panel constitutes both side surfaces of the outdoor unit 10, and includes a left panel 14 and a right panel 15. The left panel 14 and the right panel 15 are combined with the front panel 11 and the rear panel 12 to form an inner space of the outdoor unit 10. In addition, the left side panel 14 and the right side panel 15 are provided with side suction holes 14a and 15a, respectively.

The top panel 13 is coupled to an upper portion of the front panel 11, the rear panel 12, and the side panels 14 and 15 to form an upper surface of the outdoor unit 10.

In addition, the case further includes a base 17 forming a lower surface of the outdoor unit 10. As the lower surface of the base 17 is fixed to the installation position, the outdoor unit 10 may be fixed to the installation position.

Accordingly, the outdoor unit 10 may be formed with an inner space surrounded by the case, and the compressor may be disposed in the inner space. That is, the compressor or the like may be mounted on the upper surface of the base 17.

In addition, as described above, the outdoor unit 10 is formed with suction ports 12a, 14a, and 15a for sucking outdoor air and discharge ports 11a for discharging the sucked air. The discharge port 11a may be formed at the front of the case, and the suction ports 12a, 14a, and 15a may be formed at the rear or side of the case. However, this is exemplary and the discharge port and the suction port may be formed in various forms and positioned at various positions.

In addition, the outdoor unit 10 may further include a service panel 16 that covers an electrical equipment room in which a compressor or the like is installed. The service panel 16 may be formed to be rounded to one side from the front of the outdoor unit 10.

For example, the service panel 16 may be formed to be rounded from the front side of the outdoor unit 10 to the right side, and one end of the service panel 16 is fastened to the right end of the front panel 11. The other end of the service panel 16 may be fastened to the front end of the right panel 15. The service panel 16 is provided as one panel, so that the front and the side can be opened and closed at the same time, so that the installer or the manager can easily access the battlefield room.

In addition, the service panel 16 may include a service window and a service cover 16a.

The service window is an opening passing through the service panel 16, and the service cover 16a is installed to open and close the service window.

The service window may be formed to correspond to a display unit through which a user may determine and manipulate a state of the outdoor unit 10. In this case, since the display unit is exposed to the outside through the service window, the installer may check the state of the outdoor unit 10 by removing only the service cover 16a without removing the service panel 16.

In addition, the service window may be provided on the side of the outdoor unit (10). That is, the service cover 16a may be provided on the side of the outdoor unit 10, for example, on the right side of the service panel 16 as shown in FIGS. 2 and 3.

As the service window is disposed on the side of the outdoor unit 10, even when the outdoor unit 10 is located in a narrow space such as a veranda or a wall of a building, it is difficult to access the front surface of the outdoor unit 10. There is an advantage that can determine the state of the outdoor unit 10 through the service window installed in.

In addition, the outdoor unit 10 may include a partition wall 18 extending upward from the base 17 to divide the internal space into a heat exchange chamber and an electric compartment. The partition wall 18 may be understood as a configuration that prevents the moisture inside the heat exchange chamber from penetrating into the electric chamber.

The separation wall 18 is a plate extending in the vertical direction, one end may be coupled to the upper surface of the base 17. The partition wall 18 may be provided as a curved surface to correspond to the components arranged in the electrical equipment room.

The heat exchange chamber is a space where the outdoor heat exchanger 24 and the outdoor fan 32 are disposed, and the heat exchange between the refrigerant passing through the outdoor heat exchanger 24 and the external air flowing by the outdoor fan 32 is performed. It is a space made up.

The said electrical equipment room is a space where the compressor 21, the electrical equipment part 22, etc. are located. The electrical component 22 may be positioned above the electrical compartment to prevent penetration of moisture.

In addition, the internal space, the compressor 21, the oil separator, the flow switching unit (25, Figure 4), the main expansion device (27, Figure 4), the accumulator (26, Figure 4) and a plurality of refrigerant pipes are to be provided Can be. These are components for the refrigerant cycle, which will be briefly described below.

The compressor 21 is fixed to the base 18 so as to compress the refrigerant. The oil separator is disposed at the outlet side of the compressor 21 to separate oil from the refrigerant discharged from the compressor 21.

At the outlet side of the oil separator, a flow switching unit 25 for guiding the refrigerant discharged from the compressor 21 to the outdoor heat exchanger 24 or the indoor unit is disposed. The flow switching unit 25 flows the refrigerant to the outdoor heat exchanger 24 or the indoor unit in accordance with a cooling operation and a heating operation.

The outdoor heat exchanger 24 heats the outside air and the refrigerant, and functions as a condenser when the air conditioner is operated for cooling, and as an evaporator when the air conditioner is operated for heating. The outdoor heat exchanger 24 may include a heat exchange pipe 24a through which a refrigerant flows, and a heat exchange fin 24b that extends the heat exchange surface of the refrigerant and air.

When the air conditioner is cooled, the refrigerant passing through the outdoor heat exchanger 24 passes through the main expansion device 27. That is, the main expansion device 27 may be disposed at the outlet side of the outdoor heat exchanger 24 based on the cooling operation.

The accumulator 26 is disposed before the refrigerant flows into the compressor 21, that is, at the inlet side of the compressor 21 to separate the gaseous refrigerant. The gaseous phase refrigerant separated from the accumulator 26 flows into the compressor 21.

In addition, the outdoor unit 10 further includes a motor 31 and a motor mount 33 connected to the outdoor fan 32. The outdoor fan 32 is positioned to correspond to the front discharge port 11a provided in the front panel 11 and is fastened to a rotation shaft of the motor 31.

Therefore, as the motor 31 rotates, the outdoor fan 32 may force convection of the air inside the outdoor unit 10. In detail, air is introduced into the inlets 12a, 14a, and 15a formed at the rear and side surfaces of the outdoor unit 10 by the outdoor fan 32, and the air is discharged to the front discharge port 11a.

The motor 31 may be coupled to and supported by the motor mount 33. That is, the motor mount 33 may support the motor 31 and the outdoor fan 32 coupled to the motor 31.

The motor mount 33 is understood to be a structure formed between the base 17 and the top panel 13. Accordingly, one end of the motor mount 33 is fastened to the upper surface of the base 17, and the other end thereof is disposed adjacent to the lower surface of the upper panel 13.

The motor 31 and the outdoor fan 32 may be fastened to the front surface of the motor mount 33. In particular, the motor 31 and the outdoor fan 32 may be fastened to a position corresponding to the front discharge port 11a.

Referring to the flow of air passing through the outdoor unit 10 in detail, the outdoor fan 32 is rotated by the motor 31 to generate the flow of air. Air sucked through the inlets 12a, 14a, and 15a provided at the rear and side surfaces of the outdoor unit 10 passes through the outdoor heat exchanger 24 to exchange heat with the refrigerant. The air passing through the outdoor heat exchanger 24 is discharged to the outside of the outdoor unit 10 through the front discharge port 11a.

Hereinafter, the flow of the refrigerant flowing in the outdoor unit 10 will be described in detail.

4 is a view briefly illustrating a refrigerant flow of an air conditioner according to an embodiment of the present invention. FIG. 4 illustrates only a part of the above-described components to illustrate the flow of the refrigerant, and briefly illustrates the refrigerant pipes connecting the respective components. In addition, the refrigerant pipe extending to the outside of the outdoor unit to be connected to the indoor unit is omitted.

As described above, the outdoor unit 10 includes the compressor 21 and the outdoor heat exchanger 24. In addition, the outdoor unit 10 is provided with a main expansion device 27, the accumulator 26 and the flow switching unit 25.

The main expansion device 27 is configured to expand the liquid refrigerant in the high temperature and high pressure state condensed in the condenser into the liquid refrigerant in the low pressure state. For example, the main expansion device 27 may include an electric expansion valve (EEV).

That is, the main expansion device 27 is provided to change the opening rate. In this case, the opening amount may be controlled in pulse units, and the main expansion device 27 may change the opening amount within a predetermined range. For example, the opening amount of the main expansion device may be increased or decreased by 16 pulses at the maximum.

In this case, the increase in the opening amount means that the valve is opened and is represented by a positive value, and the decrease in the opening amount means that the valve is closed and is represented by a negative value. In addition, when the opening amount is increased, the amount of refrigerant flowing is increased, and when the opening amount is decreased, the amount of refrigerant flowing is decreased.

The flow switching unit 25 is disposed at the outlet side of the compressor 21 to change the direction of the refrigerant discharged from the compressor 21. For example, the flow switching unit 25 may be provided as a four-way valve.

In addition, the outdoor unit 10 is provided with a refrigerant pipe for connecting the respective components to the refrigerant flow. For convenience of description, when each refrigerant pipe is divided, the refrigerant pipe is connected to the main expansion device 27, the first pipe (40) extending to the indoor unit, the main expansion device 27 and the outdoor heat exchanger ( A second pipe 42 connecting the 24, a third pipe 44 connecting the outdoor heat exchanger 24 and the flow switching unit 25, and the accumulator 26 to pass through the flow switching unit ( 25 and the fourth pipe 46 connecting the suction side of the compressor 21, the fifth pipe 48 connecting the discharge side of the compressor 21 and the flow switching unit 25 and the flow switching A sixth pipe 50 extending from the unit 25 to the indoor unit is included.

At this time, the air conditioner according to the spirit of the present invention includes a plurality of temperature sensors for measuring the temperature. The temperature sensor may be provided in various numbers at various places, and FIG. 4 illustrates only a specific temperature sensor for convenience of description.

Hereinafter, the temperature sensor installed in the fifth pipe 48 is referred to as the first temperature sensor 52 and the temperature sensor installed in the fourth pipe 46 is referred to as the second temperature sensor 54. In addition, a temperature sensor installed outside the outdoor unit 10 to measure the outside air temperature is referred to as a third temperature sensor 56.

The first temperature sensor 52 is installed to measure the temperature of the refrigerant discharged from the compressor 21. Hereinafter, the temperature of the refrigerant measured by the first temperature sensor 52 is referred to as 'T1'.

The second temperature sensor 54 is installed to measure the temperature of the refrigerant sucked into the compressor 21. Hereinafter, the temperature of the refrigerant measured by the second temperature sensor 54 is referred to as 'T2'.

The third temperature sensor 56 is installed to measure the outdoor air temperature. Hereinafter, the temperature of the air measured by the third temperature sensor 56 is referred to as 'T3'.

Position and number of the first to third temperature sensors 52, 54, and 56 shown in FIG. 4 are exemplary, and the first to third temperature sensors 52, 54, and 56 are various to measure a desired temperature. It can be installed in various numbers at the location.

Hereinafter, the flow of the refrigerant in the operation mode of the air conditioner will be described with reference to FIG. 4.

When the air conditioner according to the spirit of the present invention performs the cooling operation, the flow of the refrigerant is shown by the dotted arrows in FIG. The cooling operation corresponds to a case where cold air is supplied to a predetermined space in which the indoor unit is installed, and the outdoor heat exchanger 24 functions as a condenser. In addition, an indoor heat exchanger disposed in the indoor unit may function as an evaporator and supply cold air to the predetermined space.

Accordingly, the low temperature low pressure refrigerant evaporated from the indoor unit is introduced into the outdoor unit 10 through the sixth pipe 50. The flow switching unit 25 connects the sixth pipe 50 and the fourth pipe 46, and thus the refrigerant flows into the compressor 21 through the accumulator 26.

The refrigerant discharged at high temperature and high pressure from the compressor 21 flows along the fifth pipe 48 and the third pipe 44. In addition, the refrigerant may be condensed in the outdoor heat exchanger 24 functioning as a condenser, and introduced into the indoor unit along the second pipe 42 and the first pipe 40 and circulated as described above. At this time, the main expansion device 27 may not completely affect the refrigerant flowing through the open.

On the other hand, when the air conditioner according to the spirit of the present invention when the heating operation the flow of the refrigerant is shown with a solid arrow in FIG. The heating operation corresponds to a case where warm air is supplied to a predetermined space in which the indoor unit is installed, and the outdoor heat exchanger 24 functions as an evaporator. In addition, the indoor heat exchanger disposed in the indoor unit functions as a condenser and may supply warmth to the predetermined space.

Accordingly, the refrigerant condensed in the indoor unit is introduced into the outdoor unit 10 through the first pipe 40. Then, it is expanded in the main expansion device 27 and flows into the outdoor heat exchanger 24 along the second pipe 42.

At this time, the outdoor heat exchanger 24 heats the outdoor air and the refrigerant to evaporate the refrigerant. The evaporated refrigerant flows along the third pipe 44 to the flow diverting part 25, and the flow diverting part 25 connects the third pipe 44 and the fourth pipe 46. . That is, the pipes different from the cooling mode are connected.

In addition, the refrigerant flows into the compressor 21 through the accumulator 26 along the fourth pipe 46. The refrigerant discharged at high temperature and high pressure from the compressor 21 flows into the fifth pipe 48, and flows along the sixth pipe 50 in the flow switching unit 25. The refrigerant may be circulated as introduced above to the indoor unit along the sixth pipe 50.

On the other hand, in general, the air conditioner when the heating operation corresponds to the winter season when the outdoor temperature is low. In particular, the lower the outdoor temperature, the more unstable the cycle and the more likely the cycle hunting phenomenon occurs.

In addition, the refrigerant flowing into the air conditioner according to the spirit of the present invention corresponds to R32. The R32 refrigerant is attracting attention as a high efficiency eco-friendly refrigerant that can produce high efficiency in a relatively small amount. However, when the R32 refrigerant is used, the temperature of the refrigerant discharged from the compressor 21 tends to be higher than that of other refrigerants.

This tendency is intensified as the outdoor air is lower, which makes the cycle unstable and deteriorates the performance of the compressor 21. In order to prevent this, the air conditioner according to the spirit of the present invention includes a control unit 60 for controlling the air conditioner by optimizing the characteristics of R32.

Hereinafter, the configuration of the air conditioner associated with the control unit 60 will be described in detail.

5 is a view showing a control configuration according to an embodiment of the present invention. 5 illustrates only a configuration necessary for convenience of description, and a configuration controlled by the controller 60 is not limited thereto.

As shown in FIG. 5, the controller 60 receives temperature information from the first to third temperature sensors 52, 54, and 56 described above. In this case, the controller 60 may receive temperature information from the first to third temperature sensors 52, 54, and 56 at predetermined time intervals. For example, temperature information may be provided at an interval of 1 minute (60 seconds).

In detail, the temperature value T1 of the refrigerant discharged to the compressor 21 measured by the first temperature sensor 52 is received and flowed into the compressor 21 measured by the second temperature sensor 54. Receive the temperature value T2 of the refrigerant. In addition, the external temperature value T3 of the outdoor unit 10 measured by the third temperature sensor 56 is received.

The controller 60 may store such temperature information in the memory 62. In detail, the controller 60 may store the temperature information provided by the first to third temperature sensors 52, 54, and 56 in the memory 62 as a value calculated by a predetermined formula.

In detail, the control unit 60 stores the change amount of the temperature value measured by the first temperature sensor 52 in the memory unit 62. At this time, a predetermined time interval described above is referred to as a cycle, and a value obtained by subtracting the previous cycle discharge temperature from the current discharge temperature is stored. This is defined as an amount of change in discharge temperature, hereinafter referred to as first information.

For example, when the predetermined time interval is 60 seconds, the period is 60 seconds. The temperature value measured by the first temperature sensor 52 60 seconds ago is T1,0 and the temperature value currently measured by the first temperature sensor 52 is T1. At this time, the control unit 60 stores the T1-T1,0 value as the first information in the memory unit 62.

In addition, the controller 60 subtracts a value T1-T2 obtained by subtracting the temperature value T2 measured by the second temperature sensor 54 from the temperature value T1 measured by the first temperature sensor 52. The memory unit 62 stores the memory 62. This is defined as the discharge superheat of the compressor 21, hereinafter referred to as second information.

In addition, the temperature value T3 measured by the third temperature sensor 56 is stored in the memory unit 62. This is defined as the external temperature of the outdoor unit 10, hereinafter referred to as third information.

As shown in FIG. 5, the controller 60 transmits a command to control the operations of the compressor 21, the outdoor fan 32, and the main expansion device EEV 27.

In detail, the control unit 60 may control the ON / OFF and driving steps of the compressor 21 and the outdoor fan 32. In this case, the controller 60 may control the operation through the frequency of the compressor 21.

In addition, the controller 60 may control the opening degree of the main expansion device 27. When the air conditioner is generally controlled (timely control), the controller 60 calculates the opening degree of the main expansion device 27 through various factors and controls it accordingly. At this time, each factor includes the discharge temperature, the refrigerant amount, the room temperature and the set temperature of the compressor (21). Such control of the main expansion device 27 is generally used and a detailed description thereof will be omitted.

At this time, the controller 60 calculates the opening degree of the main expansion device 27 at predetermined time intervals as described above. That is, as each element changes, the controller 60 may continuously calculate the opening degree of the main expansion device 27 and its value may continue to change.

For example, the controller 60 calculates the opening degree of the main expansion device 27 every 60 seconds (1 minute). That is, the amount of change in the opening degree at which the main expansion device 27 is opened or closed by a predetermined value is calculated based on the factors of the previous period.

In this case, whether the opening degree change amount is a positive value or a negative value is defined as an opening degree change, and this is called fourth information. That is, the fourth information means whether the main expansion device 27 is in a closed state or an open state. In addition, the controller 60 stores the fourth information in the memory 62.

Hereinafter, a control method of the air conditioner will be described as an example based on such a configuration.

6 and 7 illustrate control flows according to an embodiment of the present invention. 6 and 7 illustrate one control process and are shown separately for convenience of illustration.

6 and 7, the air conditioner is turned on and driven by heating operation (S10 and S11). That is, the refrigerant is circulated so that the outdoor heat exchanger 24 functions as an evaporator. At this time, the refrigerant is understood as R32.

Accordingly, the compressor 21 is driven and the start control is performed (S12). At this time, the start control is understood as a kind of driving preparation step. For example, the zero point and base value of each device can be adjusted and can be performed in about 5 minutes. In this case, when an error is detected in the start control, the air conditioner may be turned off.

When the start control is finished, the control enters the on-time control (S13). The on-time control is understood as general driving. As described above, the main expansion device 27 is controlled by the value calculated through a plurality of factors.

In the timing control, the discharge temperature (hereinafter, referred to as T1) of the compressor 21 measured by the first temperature sensor 52 is continuously monitored. For convenience of description, this step is described as checking this step once, but it can be monitored continuously by period during driving.

Accordingly, when the T1 is equal to or larger than the A value (S14), the vehicle enters emergency control (S15). The emergency control may be performed in preference to other control. That is, even if the other control conditions correspond to when the T1 or more than the A value enters the emergency control (S15).

The emergency control is performed to increase the opening degree of the main inflation device 27 by a J value at predetermined time intervals. For example, the A value may be 95 degrees and the J value may be +5 pulses. That is, when the T1 is 95 degrees or more, the opening degree of the main expansion device 27 is periodically increased by 5 pulses. In this case, the period may be 30 seconds.

In addition, when the T1 is less than the A value, the emergency control can be released. That is, in the above example, the emergency control is released when T1 is measured to be less than 95 degrees. When the emergency control is released, the control returns to the on-time control.

In addition, there may be a case where the limited control is entered from the on-time control. In order to enter the limit control in the timing control, all of the first to fourth entry conditions must be satisfied. That is, the first to fourth entry conditions correspond to an 'AND' condition.

The first to fourth entry conditions are associated with the first to fourth information described above. In this case, when the first to third information falls within a predetermined range of numerical values B, C, and D, and the fourth information is less than zero, control is entered.

In detail, the first entry condition is that the first information is greater than or equal to the B value (S16), the second entry condition is that the second information is greater than or equal to the C value (S17), and the third entry condition is the third entry condition. 3 information is less than the value D (S18), the fourth entry condition is that the fourth information is less than zero (S19). If all of the first to fourth entry conditions are satisfied, the control may be entered (S20).

As described above, the fourth information relates to whether the main expansion device 27 is in a closed state or an open state, and the fourth entry condition means that the main expansion device 27 is closed.

For example, the B value may be 3 degrees, the C value is 20 degrees, and the D value may be 0 degrees. At this time, the B value and the C value is understood as a sudden temperature value with a relatively large rise and difference, and the D value is understood as a relatively low outdoor temperature value. That is, each value is not limited thereto and may vary depending on driving conditions.

In addition, in order to release the limit control, one of the first to fourth release conditions must be satisfied. That is, the first to fourth release conditions correspond to an 'OR' condition. Alternatively, as described above, when entering the emergency control, the limit control may be released and the emergency control may be entered.

The first to fourth release conditions are associated with the first to fourth information described above. In this case, when at least one of the first to third information falls within a predetermined range of numerical values (E, F, G) or when the fourth information is zero or more, the restriction control may be released.

In detail, the first release condition is that the first information is equal to or less than the E value (S21), the second release condition is that the second information is less than the F value (S22), and the third release condition is the third The information is equal to or greater than the G value (S23), and the fourth release condition is that the fourth information is equal to or greater than 0 (S24). When any one of the first to fourth release conditions is satisfied, the limit control may be released and the timing control may be entered (S25).

For example, the E value may be 1 degree, the F value may be 18 degrees, and the G value may be 2 degrees. At this time, the E value and the F value is understood to be a stable temperature value having a relatively small rise and difference, and the G value is understood to be a relatively high outdoor temperature value. That is, each value is not limited thereto and may vary depending on driving conditions.

In addition, the fourth release condition means that the main expansion device 27 is open.

The limit control is performed to limit the amount of change in the opening degree of the main expansion device 27. That is, the amount of change in the opening degree of the main expansion device 27 calculated by the plurality of factors in the controller 60 is ignored, and the control is limited to a predetermined value.

In detail, when the first information is within a predetermined numerical range, the opening degree of the main expansion device 27 is maintained (the opening change amount = 0). At this time, the predetermined numerical range may be greater than the E value, less than the H value.

In addition, when the first information exceeds the H value, the opening degree of the main expansion device 27 may be increased to an I value. For example, the I value may be +2 pulse. The + 2pulse means opening the main inflation device 27 with a relatively small amount of change.

That is, in the limiting control, it can be understood as a control that does not change the main expansion device 27 as much as possible. Thus, the system can be stabilized.

In addition, as described above, when the first information is equal to or greater than the B value, one condition of entering the limit control is satisfied. At this time, the E value, which is the minimum value that maintains the opening degree of the main expansion device when the limiting control is performed, may be different from the B value. In addition, when performing the limit control, if the first information is equal to or less than the E value, the limit control is released.

For example, the B value may be 3 degrees, and the E value may be 1 degree. Therefore, when the first information exceeds 3 degrees, it may enter the limit control. In addition, the limit control may be released when the first information is less than or equal to 1 degree. That is, unless the other conditions are satisfied, the limit control is not released when the first information is more than 1 degree but less than 3 degrees.

The same applies to the second information and the third information.

8 is a view showing a change in the discharge temperature and the like according to the air conditioner control method according to an embodiment of the present invention. FIG. 8 shows changes in discharge temperature and frequency of the compressor according to the driving time of the air conditioner, and the amount of opening of the main expansion device EEV.

At this time, Figure 8 is shown to explain the difference from Figure 1 showing the change in the discharge temperature and the like according to the conventional control method described above may be different from the actual experimental value.

As shown in Fig. 8, as the air conditioner is turned on, start control (start-up operation) is performed in section a. In addition, after the start control, timing control (general operation) is performed in section b. This control is the same as the conventional control method shown in FIG.

At this time, the discharge temperature of the compressor is gradually increased in section b, and the first to fourth entry conditions are satisfied between section b and section c. That is, the discharge temperature of the compressor 21 is increased by a relatively large difference, the superheat degree is represented by a relatively large value, and the outdoor temperature is relatively low. In addition, the change in the opening degree of the main expansion device 27 calculated by the control unit 60 corresponds to a negative value.

Accordingly, the limit control is performed in section c. Therefore, the opening degree of the main expansion device 27 is not changed or is limited to a predetermined value. In FIG. 8, it corresponds to a condition limited to a predetermined value. As the main expansion device 27 is opened to a predetermined value, the rate of increase of the discharge temperature of the compressor 21 is reduced.

Then, between the sections c and d, any one of the first to fourth release conditions is satisfied to release the limit control. Therefore, the opening degree of the main expansion device 27 is controlled again by the timing control. At this time, the rate of change of the discharge temperature is close to zero, which is very stable.

Therefore, in the section e, the discharge temperature is kept at the same value to stabilize the cycle. In addition, it can be seen that the frequency value showing the drive of the compressor 21 continues to appear stably. That is, the compressor 21 is stably operated to have maximum efficiency.

In other words, the limiting control prevents a sudden rise in the discharge temperature, thereby stabilizing the cycle.

10: outdoor unit 21: compressor
24: outdoor heat exchanger 27: main expansion valve
52: first temperature sensor 54: second temperature sensor
56: third temperature sensor 60: control unit
T1: Compressor discharge temperature T2: Compressor inlet temperature
T3: outside temperature

Claims (14)

In the control method of the air conditioner including a compressor, an outdoor heat exchanger and an outdoor unit having a main expansion device,
The outdoor heat exchanger functions as an evaporator,
Measure the discharge temperature of the refrigerant discharged from the compressor and store the change amount (first information);
Measuring the discharge temperature and the temperature of the refrigerant flowing into the compressor and storing the difference (second information);
Measure and store the external temperature (third information) of the outdoor unit,
By changing the opening degree (fourth information) of the main expansion device,
When the first to third information falls within a predetermined range of values B, C, and D, and the fourth information is less than zero, the controller enters the limiting control for limiting the amount of change in the opening degree of the main expansion device. Control method of the air conditioner. The method of claim 1,
The first information is equal to or greater than the B value (first entry condition),
The second information is equal to or greater than the C value (second entry condition),
The third information is less than the D value (third entry condition),
If the fourth information is less than zero (fourth entry condition),
The control method of the air conditioner, characterized in that the entry into the limit control. The method of claim 1,
When performing the limit control,
The restriction control is released when at least one of the first to third pieces of information falls within a predetermined range of numerical values (E, F, G) or when the fourth information is zero or more. Control method. The method of claim 3, wherein
When performing the limit control,
The first information is equal to or less than the E value (first release condition),
The second information is less than the F value (second release condition),
The third information is equal to or greater than the G value (third release condition),
When the fourth information is 0 or more (fourth release condition),
The control method of the air conditioner, characterized in that the restriction control is released. The method of claim 1,
Measuring the discharge temperature of the refrigerant discharged from the compressor, and when the discharge temperature is equal to or greater than the A value, the emergency control method of the air conditioner, characterized in that entered. The method of claim 5,
When performing the emergency control, increase the opening degree of the main inflator by J value at predetermined time intervals,
And the emergency control is released when the discharge temperature is lower than the A value. The method of claim 1,
When performing the limit control,
When the first information is within a predetermined numerical range, the opening degree of the main expansion device is maintained (opening amount change = 0),
And when the first information exceeds the H value, increasing the opening degree of the main expansion device to an I value. The method of claim 7, wherein
When the first information is equal to or greater than the B value, one condition of entering the limit control is satisfied
When the limit control is performed, when the first information is greater than the E value and less than the H value, the opening degree of the main expansion device is maintained.
The B value and the E value is a control method of the air conditioner, characterized in that different from each other. The method of claim 1,
When performing the limit control,
If the first information is equal to or less than the E value, the restriction control is released;
When the first information is greater than the E value or less than the H value, the opening degree of the main expansion device is maintained (opening amount change = 0),
And when the first information exceeds the H value, increases the opening degree of the main expansion device to an I value. The method according to any one of claims 7 and 9,
The I value is a control method of the air conditioner, characterized in that + 2pulse. The method of claim 1,
When the first information is 3 degrees or more, one condition of the limit control entry is satisfied,
And the limit control is released when the first information is 1 degree or less when the limit control is performed. The method of claim 1,
When the second information is 20 degrees or more, one condition of entering the limit control is satisfied,
And the limit control is released when the second information is less than 18 degrees when the limit control is performed. The method of claim 1,
When the third information is less than 0 degrees, one condition of entering the limit control is satisfied,
And the limit control is released when the third information is 2 degrees or more when the limit control is performed. The method of claim 1,
The refrigerant is a control method of an air conditioner, characterized in that R32.

Images