KR20190036277A - A method for controlling an air conditioner - Google Patents

Abstract

The present invention relates to a method to control an air conditioner. According to the present invention, the air conditioner comprises: a compressor; and an outdoor unit including an outdoor heat exchanger and a main expansion apparatus. According to the present invention, the method to control the air conditioner comprises the following steps of: making the outdoor heat exchanger work as an evaporator; measuring the discharge temperature of a refrigerant discharged from the compressor to store the variation (first information); measuring the temperature of the refrigerant introduced into the compressor to store the difference between the discharge temperature and the temperature of the refrigerant (second information); measuring the external temperature of the outdoor unit (third information); storing a change of opening of the main expansion apparatus (fourth information); and limiting an opening variation of the main expansion apparatus when the first to third information respectively come under a certain range of value (B, C, D) and the fourth information is smaller than 0. According to the present invention, the method to control the air conditioner is able to provide an optimized method to control the air conditioner in accordance with the characteristics of R32.

Description

TECHNICAL FIELD The present invention relates to a control method for an air conditioner,

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

Generally, an air conditioner means a device for adjusting the room temperature to create a comfortable indoor air environment.

The air conditioner includes an indoor unit installed in the room and an outdoor unit supplying the refrigerant to the indoor unit. One or more indoor units may be connected to the outdoor unit. In addition, the outdoor unit may include a compressor, an outdoor heat exchanger, and a main expansion device.

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

First, the flow of the refrigerant when the air conditioner operates in the cooling operation will be described. The refrigerant compressed in the compressor of the outdoor unit becomes liquid refrigerant of medium temperature and high pressure through the outdoor heat exchanger functioning as a condenser. When the liquid refrigerant is supplied to the indoor unit, the refrigerant expands in the indoor heat exchanger functioning as the evaporator, and vaporization may occur. 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 into the room.

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

Meanwhile, when the outdoor unit (outdoor temperature) of the outdoor unit is too low when the air conditioner performs the heating operation, the cyclic hunting phenomenon may occur. In particular, when R32, which is attracting attention as an eco-friendly refrigerant, is used, there is a high possibility that cyclic hunting phenomenon occurs because the pressure rises suddenly as compared with other refrigerants.

Hereinafter, a detailed description will be given with reference to the drawings.

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

1, section a corresponds to start control (start operation), and section b corresponds to on-time control (normal operation). At this time, although the discharge temperature of the compressor is increased in the section c, the amount of opening of the main expansion device is continuously reduced to reduce the amount of refrigerant. As a result, the discharge temperature rises sharply and the emergency control is performed in the section d.

At this time, although the emergency control is performed to rapidly increase the opening amount of the main expansion device, the discharge temperature continues to rise. As a result, the frequency of the compressor is rapidly lowered and cycle hunting can occur. Also, it can be seen that the ejection temperature continuously changes even in the period e where the ejection temperature is lowered, and it is in an unstable state.

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

It is an object of the present invention to provide a control method of an air conditioner optimized according to characteristics of R32.

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

The control method of an air conditioner according to an embodiment of the present invention includes a compressor, an outdoor heat exchanger, and an outdoor unit including an outdoor unit having a main expansion device, wherein the outdoor heat exchanger functions as an evaporator, (First information), stores the difference between the discharge temperature and the temperature of the refrigerant flowing into the compressor, stores the difference (second information), and controls the temperature of the refrigerant discharged from the outdoor unit (B), (C), and (D) of the first to third pieces of information are stored in the main expansion unit And when the fourth information is smaller than 0, enters the restriction control for limiting the change amount of the opening of the main expansion device.

Wherein the first information is a B value or more (first entry condition), the second information is a C value or more (second entry condition), the third information is less than D value (third entry condition) 4 information is smaller than 0 (fourth entry condition), it can enter the restriction control.

If at least one of the first to third pieces of information corresponds to a predetermined range of values (E, F, G) or the fourth piece of information is equal to or larger than 0, the restriction control may be canceled .

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 more than the G value Release condition), and when the fourth information is 0 or more (fourth release condition), the restriction control may be released.

The discharge temperature of the refrigerant discharged from the compressor may be measured, and if the discharge temperature is equal to or higher than the A value, it may enter the emergency control.

In the emergency control, the opening degree of the main expansion device is increased by J value at a predetermined time interval, and when the discharge temperature is lower than the A value, the emergency control can be released.

Wherein when the first information is in the predetermined numerical range, the opening degree of the main expansion device is maintained (opening change amount = 0), and when the first information exceeds the H value, Can be increased to an I value.

Wherein when the first information is equal to or greater than the B value, one condition of the restriction control entry is satisfied, and when the first information is equal to or greater than the E value and equal to or less than the H value during the restriction control, The B value and the E value may be different from each other.

When the first information is equal to or less than the E value, the restriction control is released. When the first information is equal to or more than the E value and H value or less, the opening degree of the main expansion device is maintained = 0), and when the first information exceeds the H value, the opening degree of the main expansion device can be increased to an I value.

The I value may be +2 pulses.

When the first information is equal to or greater than three degrees, one condition of the restriction control entry is satisfied, and when the first information is equal to or less than one degree at the time of performing the restriction control, the restriction control may be released.

If the second information is 20 degrees or more, one condition of the restriction control entry is satisfied, and if the second information is less than 18 degrees when the restriction control is performed, the restriction control may be released.

When the third information is less than 0 degree, one condition of the restriction control entry is satisfied, and when the third information is more than 2 degrees when the restriction control is performed, the restriction control may be released.

The refrigerant may be R32.

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

According to the embodiment of the present invention, the control method of the air conditioner optimized for the environment-friendly refrigerant R32 is provided, and R32 can be used more effectively.

Specifically, there is an advantage that stabilization of the cycle operation can be achieved by preventing sudden rise of the compressor discharge temperature.

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

In addition, since the new refrigerant (R32) is used, the unit price can be reduced and the price competitiveness can be ensured.

Further, as the cycle is operated stably, there is an advantage that the compressor can be operated with maximum efficiency.

Further, there is an advantage that it is possible to perform control in accordance with a new refrigerant more easily by controlling it with software without a separate device.

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

An air conditioner according to an embodiment 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 one refrigeration cycle. Hereinafter, only the outdoor unit is shown for convenience of explanation.

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

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

The outdoor unit (10) includes a case which forms an appearance and contains a large number 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 a front discharge port 11a through which air is discharged to the outside of the outdoor unit 10 is provided.

The rear panel 12 is spaced rearward from the front panel 11 so as to form an inner space of the outdoor unit 10. Also, the rear panel 12 is provided with a rear suction port 12a through which air is sucked into the outdoor unit 10.

The side panels constitute both side surfaces of the outdoor unit 10 and include a left panel 14 and a right panel 15. The left panel 14 and the right panel 15 are coupled to the front panel 11 and the rear panel 12 to form an internal space of the outdoor unit 10. The left panel 14 and the right panel 15 are provided with side suction ports 14a and 15a, respectively.

The upper panel 13 is coupled to the upper portions of the front panel 11, the rear panel 12 and the side panels 14 and 15 so as to constitute the upper surface of the outdoor unit 10.

Further, the case further includes a base 17 constituting the 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 can be fixed to the installation position.

Accordingly, the outdoor unit 10 is formed with an inner space surrounded by the case, and a compressor or the like to be described later 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.

As described above, the outdoor unit (10) is provided with the suction ports (12a, 14a, 15a) for sucking outdoor air and the discharge port (11a) through which the sucked air is discharged. The discharge port 11a may be formed in the front of the case, and the suction ports 12a, 14a, and 15a may be formed on the rear or side of the case. However, this is merely an example, and the discharge port and the suction port may be formed in various forms and may be located at various positions.

The outdoor unit (10) may further include a service panel (16) that covers an electric room including a compressor and the like. The service panel 16 may be formed to be rounded to one side from the front surface of the outdoor unit 10.

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

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

The service window is an opening 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 so as to correspond to a display unit that allows the user to determine and operate the state of the outdoor unit 10. [ At this time, since the display unit is exposed to the outside through the service window, the installer can remove the service panel 16 and remove only the service cover 16a to check the state of the outdoor unit 10. [

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

The service window is disposed on the side surface of the outdoor unit 10 so that even when the outdoor unit 10 is disposed in a narrow space such as a veranda or a wall of a building and is difficult to access the front side, It is possible to grasp the state of the outdoor unit 10 through a service window installed in the outdoor unit 10.

The outdoor unit 10 may further include a partition wall 18 extending upward from the base 17 to divide the interior space into a heat exchange chamber and an electric compressor chamber. The separating wall 18 prevents the moisture in the heat exchange chamber from penetrating into the electric field chamber.

The separating wall 18 is a plate extending in the vertical direction, and one end thereof may be coupled to the upper surface of the base 17. The separating wall 18 may be formed in a curved surface so as to correspond to the arrangements disposed in the electric field chamber.

The heat exchange chamber is a space in which 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 outside air flowing by the outdoor fan 32 .

The electric room is a space in which the compressor (21) and the front section (22) are located. The front portion 22 may be positioned on top of the electric field chamber to prevent penetration of moisture

The internal space is provided with a compressor 21, an oil separator, a flow switching unit 25 (Fig. 4), a main expansion device 27 (Fig. 4), an accumulator 26 . This is a constitutional device for a refrigerant cycle. Hereinafter, a refrigerant cycle will be briefly described.

The compressor (21) is fixed to the base (18) to compress the refrigerant. The oil separator is disposed at the outlet side of the compressor (21) and separates oil from the refrigerant discharged from the compressor (21).

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 at the outlet side of the oil separator. The flow switching unit 25 causes the refrigerant to flow toward the outdoor heat exchanger 24 or the indoor unit in accordance with the cooling operation and the heating operation.

The outdoor heat exchanger 24 exchanges heat between the outside air and the refrigerant, and functions as a condenser when the air conditioner performs cooling operation and as an evaporator when the air conditioner performs heating operation. The outdoor heat exchanger 24 may include a heat exchange pipe 24a through which the refrigerant flows and a heat exchange pin 24b that expands the heat exchange surface between the refrigerant and the air.

When the air conditioner performs the cooling operation, the refrigerant that has passed through the outdoor heat exchanger (24) passes through the main expansion device (27). That is, the main expansion device 27 can be disposed on the outlet side of the outdoor heat exchanger 24 on the basis of 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 refrigerant separated from the accumulator (26) flows into the compressor (21).

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 of the front panel 11 and is fastened to the rotary shaft of the motor 31. [

Therefore, according to the rotation of the motor 31, the outdoor fan 32 can forcedly convect the air inside the outdoor unit 10. More specifically, the outdoor fan 32 introduces air into the inlets 12a, 14a, and 15a formed on the rear and side surfaces of the outdoor unit 10, and 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 can 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 upper panel 13. Therefore, one end of the motor mount 33 is fastened to the upper surface of the base 17, and the other end 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 at positions corresponding to the front discharge port 11a.

The flow of air passing through the outdoor unit (10) will be described in detail. The outdoor unit (32) is rotated by the motor (31) to generate a flow of air. Air sucked through the inlets (12a, 14a, 15a) provided on the rear and side surfaces of the outdoor unit (10) passes through the outdoor heat exchanger (24) and performs heat exchange with the refrigerant. The air having passed 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 into the outdoor unit 10 will be described in detail.

FIG. 4 is a view schematically showing a refrigerant flow of an air conditioner according to an embodiment of the present invention. FIG. 4 shows only a part of the structure described above to show the flow of the refrigerant, and a refrigerant pipe connecting the components is schematically shown. Also, 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) is provided with the compressor (21) and the outdoor heat exchanger (24). The outdoor unit 10 is provided with a main expansion device 27, an accumulator 26, and a 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 to 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. At this time, the opening amount can be controlled in a pulse unit, and the opening amount of the main expansion device 27 can be changed within a predetermined range. For example, the opening amount of the main expansion device can be increased or decreased by a maximum of 16 pulses.

At this time, the increase of the opening amount means that the valve is opened and is represented by (+) value, and the decrease of the opening amount means that the valve is closed and it is indicated by (-) value. Also, when the opening amount is increased, the amount of the refrigerant flowing increases, and when the opening amount is decreased, the amount of the refrigerant flowing decreases.

The flow switching unit 25 is disposed at the outlet side of the compressor 21 and switches 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 through which respective components are connected to flow the refrigerant. The refrigerant pipe is provided with a first pipe 40 connected to the main expansion device 27 and extending to the indoor unit, a second pipe 40 connected to the main expansion device 27 and the outdoor heat exchanger A third pipe 44 connecting the outdoor heat exchanger 24 and the flow switching unit 25 and a third pipe 44 connecting the outdoor heat exchanger 24 and the flow switching unit 25 through the accumulator 26, 25) and a suction side of the compressor (21), a fifth pipe (48) connecting the discharge side of the compressor (21) to the flow switching portion (25) And a sixth pipe (50) extending from the second pipe (25) to the indoor unit.

In this case, the air conditioner according to the present invention includes a plurality of temperature sensors for measuring the temperature. The temperature sensors may be provided in various numbers in various places, and only a specific temperature sensor is shown in FIG. 4 for convenience of explanation.

Hereinafter, a temperature sensor installed in the fifth pipe 48 is referred to as a first temperature sensor 52, and a temperature sensor provided in the fourth pipe 46 is referred to as a second temperature sensor 54. A temperature sensor provided outside the outdoor unit 10 for measuring the outdoor 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 outdoor air temperature. Hereinafter, the temperature of the air measured by the third temperature sensor 56 is referred to as 'T3'.

The positions and numbers 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 may be various And can be installed in various positions in the position.

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

The flow of the refrigerant when the air conditioner according to the present invention is operated in the cooling mode is indicated by a dashed arrow in FIG. Cooling operation corresponds to a case where cool air is supplied to a predetermined space provided with the indoor unit, and the outdoor heat exchanger 24 functions as a condenser. In addition, the indoor heat exchanger disposed in the indoor unit functions as an evaporator and can supply cold air to the predetermined space.

Accordingly, the low-temperature and low-pressure refrigerant evaporated in the indoor unit through the sixth pipe (50) flows into the outdoor unit (10). The flow switching unit 25 connects the sixth piping 50 and the fourth piping 46 so that the refrigerant flows into the compressor 21 through the accumulator 26.

The refrigerant discharged from the compressor (21) at high temperature and high pressure flows along the fifth pipe (48) and the third pipe (44). The refrigerant is condensed in the outdoor heat exchanger 24 functioning as a condenser and flows into the indoor unit along the second pipe 42 and the first pipe 40 so as to be circulated as described above. At this time, the main expansion device 27 may not have any influence on the refrigerant being completely opened and flowing.

Meanwhile, when the air conditioner according to the present invention operates in a heating operation, the flow of the refrigerant is indicated by a solid line arrow in FIG. The heating operation corresponds to a case where warm air is supplied to a predetermined space provided with the indoor unit, 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 can supply warmth to the predetermined space.

Accordingly, the refrigerant condensed in the indoor unit flows into the outdoor unit (10) through the first pipe (40). The refrigerant 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) exchanges heat between the outdoor air and the refrigerant to evaporate the refrigerant. The evaporated refrigerant flows along the third pipe 44 to the flow switching unit 25 and the flow switching unit 25 connects the third pipe 44 and the fourth pipe 46 . That is, different pipes are connected to the cooling mode.

The refrigerant passes through the accumulator (26) along the fourth pipe (46) and flows into the compressor (21). The refrigerant discharged from the compressor 21 at a high temperature and a high pressure flows into the fifth pipe 48 and flows along the sixth pipe 50 in the flow switching unit 25. The refrigerant may flow into the indoor unit along the sixth pipe 50 and may be circulated as described above.

On the other hand, when the air conditioner performs the heating operation in general, it corresponds to the winter season in which 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 will occur.

The refrigerant flowing into the air conditioner according to the present invention corresponds to R32. The R32 refrigerant has attracted attention as a highly efficient eco-friendly refrigerant capable of achieving high efficiency with 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 other refrigerants.

Such a tendency is exacerbated as the outdoor air is lowered, thereby making the cycle unstable and deteriorating the performance of the compressor (21). In order to prevent this, the air conditioner according to the present invention includes a controller 60 for controlling the air conditioner optimally to the characteristics of R32.

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

5 is a diagram illustrating a control configuration according to an embodiment of the present invention. 5 shows only the necessary configuration for convenience of explanation, and the 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. At this time, 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 can be provided at intervals of 1 minute (60 seconds).

Specifically, the refrigerant temperature T 1 of the refrigerant discharged to the compressor 21 measured by the first temperature sensor 52 is received, and the refrigerant is supplied to the compressor 21 measured by the second temperature sensor 54 And receives the temperature value T2 of the refrigerant. The outdoor temperature T3 of the outdoor unit 10 measured by the third temperature sensor 56 is also received.

The control unit 60 may store the temperature information in the memory unit 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 unit 62 as a value calculated by a predetermined formula.

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

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

The control unit 60 calculates 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 And stores it in the memory unit 62. This is defined as the discharge overheating degree of the compressor (21), hereinafter referred to as second information.

Also, the temperature value T3 measured by the third temperature sensor 56 is stored in the memory unit 62. This is defined as the outside temperature of the outdoor unit (10), and is hereinafter referred to as third information.

5, the control unit 60 transmits a command for controlling the operation of the compressor 21, the outdoor fan 32, and the main expansion unit (EEV) 27.

In detail, the control unit 60 can control ON / OFF and drive steps of the compressor 21 and the outdoor fan 32. [ At this time, the controller 60 can control its 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 (on-time control), the controller 60 calculates the opening degree of the main expansion device 27 through various factors and controls the opening degree of the main expansion device 27 accordingly. At this time, factors include the discharge temperature of the compressor (21), the refrigerant quantity, the room temperature, the set temperature, and the like. The 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 a predetermined time interval as described above. That is, as each element is changed, the controller 60 continues to calculate the opening of the main expansion device 27, and the value thereof can be continuously changed.

For example, the controller 60 calculates the opening of the main expansion device 27 at intervals of 60 seconds (1 minute). That is, the main expansion device 27 calculates the amount of opening change that the main expansion device 27 opens or closes by a predetermined value by each factor of the previous period.

At this time, whether the opening change amount is a (+) value or a (-) value is defined as an opening degree change and is referred to as fourth information. That is, the fourth information means whether the main expansion device 27 is closed or opened. In addition, the control unit 60 stores the fourth information in the memory unit 62. [

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

FIG. 6 and FIG. 7 are diagrams showing a control flow according to an embodiment of the present invention. 6 and 7 illustrate one control process and are shown separately for convenience of illustration.

As shown in Figs. 6 and 7, the air conditioner is turned on and driven by the heating operation (S10, 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 startup control is performed (S12). At this time, the start-up control is understood to be a kind of drive preparation step. For example, the zero and basal values of each device can be adjusted and can be performed for about 5 minutes or less. At this time, if an error is detected in the startup control, the air conditioner may be turned off.

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

The on-time control continuously monitors the discharge temperature (hereinafter referred to as " T1 ") of the compressor 21 measured by the first temperature sensor 52. [ For the convenience of description, it is described in FIG. 6 that this step is checked once, but it can be continuously monitored for each cycle during driving.

Accordingly, if T1 is equal to or more than the A value (S14), emergency control is started (S15). The emergency control can be performed in preference to other controls. That is, even if the other control conditions are met, the emergency control is entered if the value of T1 is equal to or greater than the A value (S15).

The emergency control is performed so as to increase the opening degree of the main expansion device 27 by a predetermined number of time intervals. For example, the A value may be 95 degrees and the J value may be + 5pulse. That is, when T1 is equal to or greater than 95 degrees, the opening degree of the main expansion device 27 is periodically increased by 5 pulses. At this time, the cycle may be 30 seconds.

Further, when T1 is less than the A value, the emergency control can be released. That is, in the above example, when T1 is measured to be less than 95 degrees, the emergency control is released. When the emergency control is canceled, the control enters the regular control again.

Then, there is a case in which the time control enters the limit control. In order to enter the limit control from the time control, the first to fourth entry conditions must be satisfied. That is, the first to fourth entry conditions correspond to the 'AND' condition.

The first to fourth entry conditions are associated with the first to fourth information described above. At this time, if the first to third pieces of information correspond to the predetermined range of values (B, C, D) and the fourth piece of information is less than 0,

More specifically, the first entry condition is that the first information is greater than or equal to the B value (S16), the second entry condition is the C number or more (S17) 3 information is less than the D value (S18), and the fourth entry condition is that the fourth information is less than 0 (S19). If all of the first to fourth entry conditions are satisfied, the restriction control may be entered (S20).

As described above, the fourth information relates to whether the main expansion device 27 is in the closed state or the 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 may be 20 degrees, and the D value may be 0 degrees. At this time, the B value and the C value are understood to be abrupt temperature values with relatively large rise and difference, and the D value is understood as a comparatively low outdoor temperature value. That is, the numerical values are not limited thereto and may vary depending on operating conditions and the like.

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

The first to fourth release conditions are associated with the first to fourth information described above. At this time, if at least one of the first to third information corresponds to each predetermined numerical value (E, F, G) or if the fourth information is 0 or more, the restriction control may be canceled.

More specifically, 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), the third release condition is the third release condition The information is a G value or more (S23), and the fourth release condition is that the fourth information is 0 or more (S24). If any one of the first to fourth release conditions is satisfied, the restriction control is released and the control can be entered into the on-time control (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 are understood as a stable temperature value with relatively small rise and difference, and the G value is understood as a comparatively high outdoor temperature value. That is, the numerical values are not limited thereto and may vary depending on operating conditions and the like.

Further, the fourth release condition means that the main expansion device 27 is being opened.

The limiting control is performed to limit the amount of change in opening of the main expansion device (27). That is, the control unit 60 ignores the amount of opening change of the main expansion device 27 calculated by a plurality of factors, and restricts the opening amount to a predetermined value.

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

Further, when the first information exceeds the H value, the opening degree of the main expansion device 27 can be increased to the I value. For example, the I value may be +2 pulses. The + 2pulse means that the main expansion device 27 is opened with a relatively small change amount.

That is, in the restriction 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.

Further, as described above, when the first information is equal to or greater than the B value, one condition of the restriction control entry is satisfied. At this time, the minimum value E that maintains the opening degree of the main expansion device during the restriction control may be a numerical value different from the B value. When the first information is equal to or less than the E value at the time of performing the restriction control, the restriction 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 can enter the restriction control. And, the restriction control can be released only when the first information is less than 1 degree. That is, the restriction control is not released when the first information is more than 1 degree and less than 3 degrees, unless another condition is satisfied.

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

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

Here, FIG. 8 is shown to explain the difference from FIG. 1 showing the change of the discharge temperature or the like according to the conventional control method described above, and may be different from an actual experimental value.

As shown in Fig. 8, as the air conditioner is turned on, startup control (startup operation) is performed in a section a. After the start-up control, the normal control (normal operation) is performed in the section b. This control is the same as the conventional control method shown in Fig.

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

Accordingly, the limit control is performed in the section c. Therefore, the amount of opening change of the main expansion device 27 is not present or limited to a predetermined value. In FIG. 8, the condition is 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.

In the interval c, any one of the first to fourth release conditions is satisfied between the interval d, and the restriction control is released. Therefore, the opening degree of the main expansion device 27 is controlled again on a regular basis. At this time, the rate of change of the discharge temperature is almost zero and is very stabilized.

Therefore, the discharge temperature is maintained at the same value continuously in the period e, and the cycle is stabilized. In addition, it can be seen that the frequency value showing the driving of the compressor 21 continues to appear stably. That is, the compressor 21 is operated stably so as to have the maximum efficiency.

In other words, by the restriction control, the discharge temperature is prevented from suddenly rising, and the cycle can be stabilized.

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:
T1: compressor discharge temperature T2: compressor inlet temperature
T3: Outside temperature

Claims (14)

A control method for an 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,
A discharge temperature of the refrigerant discharged from the compressor is measured to store the change amount (first information)
The discharge temperature and the temperature of the refrigerant flowing into the compressor are measured to store the difference (second information)
The outdoor temperature (third information) of the outdoor unit is measured and stored,
(Fourth information) of the opening degree of the main expansion device,
When the first to third pieces of information correspond to a predetermined range of values (B, C, D) and the fourth information is smaller than 0, the control unit enters restriction control for limiting the amount of opening change of the main expansion device Wherein the air conditioner is controlled by the air conditioner. The method according to claim 1,
If the first information is equal to or greater than the B value (first entry condition)
If the second information is a C value or more (second entry condition)
If the third information is less than the D value (third entry condition)
When the fourth information is smaller than 0 (fourth entry condition)
Wherein the controller enters the restriction control. The method according to claim 1,
When performing the restriction control,
Wherein the limiting control is released when at least one of the first to third information corresponds to a predetermined range of values (E, F, G) or the fourth information is equal to or greater than zero Control method. The method of claim 3,
When performing the restriction control,
If the first information is equal to or less than the E value (first release condition)
If the second information is less than the F value (second release condition)
If the third information is G number or more (third release condition)
When the fourth information is 0 or more (fourth release condition)
And the restriction control is released. The method according to claim 1,
Wherein the control unit measures the discharge temperature of the refrigerant discharged from the compressor and enters the emergency control when the discharge temperature is equal to or higher than the A value. 6. The method of claim 5,
Increasing the opening of the main expansion device by J values at predetermined time intervals during the execution of the emergency control,
And the emergency control is released when the discharge temperature is lower than the A value. The method according to claim 1,
When performing the restriction control,
When the first information is in a predetermined numerical range, the opening degree of the main expansion device is maintained (opening amount of change = 0)
And increases the opening degree of the main expansion device to an I value when the first information exceeds the H value. 8. The method of claim 7,
When the first information is equal to or greater than the B value, a condition of the restriction control entry is satisfied,
Wherein when the first information is equal to or greater than the E value and equal to or less than the H value at the time of performing the restriction control, the opening degree of the main expansion device is maintained,
Wherein the B value and the E value are different from each other. The method according to claim 1,
When performing the restriction control,
When the first information is equal to or less than the E value, the restriction control is released,
And maintains the opening degree of the main expansion device (opening amount change amount = 0) when the first information is equal to or more than the E value and H value or less,
Wherein when the first information exceeds the H value, the opening degree of the main expansion device is increased to an I value. 10. The method according to claim 7 or 9,
Wherein the I value is + 2pulse. The method according to claim 1,
Wherein if the first information is greater than or equal to three degrees,
Wherein when the first information is less than or equal to one degree, the restriction control is canceled. The method according to claim 1,
If the second information is 20 degrees or more, satisfies a condition of the restriction control entry,
Wherein when the second information is less than 18 degrees, the restriction control is canceled. The method according to claim 1,
And when the third information is less than 0 degree, satisfies a condition of the restriction control entry,
Wherein when the third information is greater than or equal to two degrees, the restriction control is canceled. The method according to claim 1,
Wherein the refrigerant is R32.

Images