KR20130027292A - An air conditioner and a control method the same - Google Patents

Abstract

PURPOSE: An air conditioner and a controlling method thereof are provided to allow a refrigerant, which passes through a condenser, to bypass a phase separator in cooling operation, thereby preventing pressure drop generated when the refrigerant passes through an expanding apparatus. CONSTITUTION: An air conditioner comprises a compressor(10), a condenser, a phase separator(100), multiple expanding apparatuses(120), and a bypass flow path(160). The compressor compresses a refrigerant. The condenser condenses the refrigerant compressed by the compressor. The phase separator separates a gaseous refrigerant from the refrigerant which passes through the condenser. The expanding apparatus is installed at least one side of the phase separator, and expands the refrigerant which flows in the phase separator, or the refrigerant which is discharged from the phase separator. In one operational mode, the bypass flow path bypasses the refrigerant at the inlet of the phase separator toward the outlet of the phase separator.

Description

An air conditioner and a control method the same

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

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

In detail, the air conditioner is driven by a refrigeration cycle that performs the compression, condensation, expansion and evaporation process of the refrigerant, thereby performing the cooling or heating operation of the indoor space.

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

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

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

On the other hand, the air conditioner may be provided with a phase separator for bypassing at least some of the refrigerant circulating the refrigeration cycle, the gas phase refrigerant is injected into the compressor.

Referring to FIG. 4, a conventional air conditioner includes a phase separator 4 provided between an outdoor heat exchanger 2 and an indoor heat exchanger 3 to separate a phase of a refrigerant.

When the air conditioner performs the cooling operation, the refrigerant condensed in the outdoor heat exchanger (2) flows into the phase separator (4) through the first expansion device (5), and the liquid refrigerant and the phase separator (4). The gaseous refrigerant is separated. The separated liquid refrigerant flows to the indoor heat exchanger 3 through the second expansion device 6. The separated gaseous refrigerant is injected into the compressor 1 via the third expansion device 7.

On the other hand, when the air conditioner performs the heating operation, the refrigerant condensed in the indoor heat exchanger (3) flows into the phase separator (4) through the second expansion device (6), the phase separator (4) In the liquid and gaseous refrigerant is separated. The separated liquid refrigerant flows to the outdoor heat exchanger 2 via the first expansion device 5. The separated gaseous refrigerant is injected into the compressor 1 via the third expansion device 7.

As such, by injecting some of the refrigerant circulating in the refrigeration system into the compressor, it is possible to ensure the amount of the refrigerant circulating in the compressor, thereby improving the cooling and heating ability.

However, the amount of system refrigerant required when the air conditioner performs the heating operation is larger than the amount of system refrigerant required when the air conditioner performs the cooling operation. Accordingly, the effect obtained by injecting into the compressor 1 is larger in the case of heating operation than in cooling operation.

That is, although the demand for the compressor injection is not great during the cooling operation, as described above, the first expansion device 5 and the second expansion device 6 in the process of passing the refrigerant through the phase separator 4. ), The pressure drops by passing through all of them. In this case, the heat exchange efficiency of the refrigeration cycle is lowered, there is a problem that the cooling capacity is reduced.

The present invention has been proposed to solve such a problem, and an object of the present invention is to provide an air conditioner that allows a refrigerant to bypass a phase separator during a cooling operation, thereby providing a cooling capability.

In an air conditioner according to an embodiment of the present invention, an air conditioner in which a refrigeration cycle is driven and the operation mode can be switched includes: a compressor for compressing a refrigerant; A condenser for condensing the refrigerant compressed in the compressor; A phase separator for separating the gaseous refrigerant from the refrigerant passing through the condenser; A plurality of expansion devices provided on at least one side of the phase separator, for expanding the refrigerant flowing into the phase separator or the refrigerant flowing out of the phase separator; And a bypass flow path for bypassing the inlet refrigerant of the phase separator to the outlet side of the phase separator in one of the operation modes.

According to another aspect of the present invention, a control method of an air conditioner includes a refrigeration cycle including a compressor, a condenser, an expansion device, and an evaporator, and an air conditioner including a phase separator for separating a gaseous refrigerant from the refrigerant passing through the condenser. A method, comprising: recognizing an operating mode of an air conditioner; Determining whether the refrigerant passing through the condenser is introduced into the phase separator according to the operation mode; And the refrigerant passing through the condenser is bypassed to the outlet side of the phase separator when the operation mode is the first mode, and the refrigerant passing through the condenser is introduced into the phase separator when the operation mode is the second mode. .

According to the present invention, the refrigerant passing through the condenser during the cooling operation does not pass through the phase separator, there is an effect that can prevent the pressure drop phenomenon that may occur by passing through the expansion device. By preventing the pressure drop of the refrigerant, there is an advantage that can improve the heat exchange efficiency and cooling capacity of the refrigeration system.

In addition, since the refrigerant passing through the condenser in the heating operation passes through the phase separator to separate the gaseous refrigerant, and the separated gaseous refrigerant may be injected into the compressor, the amount of refrigerant circulating in the compressor may be increased. Accordingly, there is an advantage that the heating ability can be improved.

In addition, the refrigerant is configured to pass through the phase separator only during the heating operation, thereby increasing the phase separation efficiency of the phase separator and increasing the reliability of the phase separator operation.

In addition, since the gas phase pipe extends above the phase separator and the liquid phase pipe extends below the phase separator, the separation efficiency of the liquid refrigerant and the gaseous refrigerant in the phase separator may be increased, thereby improving heating capability.

1 is a system diagram showing the configuration of an air conditioner according to an embodiment of the present invention.
2 is a view showing a refrigerant flow in the phase separator according to an embodiment of the present invention.
3 is a flow chart showing a control method of an air conditioner according to an embodiment of the present invention.
4 is a view showing a conventional phase separator configuration.

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

1 is a system diagram showing the configuration of an air conditioner according to an embodiment of the present invention.

Referring to FIG. 1, a refrigeration cycle in which a refrigerant circulates is driven in an air conditioner 1 according to an embodiment of the present invention. The air conditioner 1 may be cooled or heated according to the circulation direction of the refrigerant.

When the air conditioner 1 performs a cooling operation, the air conditioner 1 includes a compressor 10 for compressing a refrigerant and a liquid refrigerant for separating liquid refrigerant from the refrigerant sucked into the compressor 10. A gas-liquid separator 40, an outdoor heat exchanger 30 for allowing the refrigerant compressed by the compressor 10 to exchange heat with outdoor air, and a first expansion device for expanding the refrigerant condensed in the outdoor heat exchanger 20. (110), an indoor heat exchanger (20) for allowing the refrigerant expanded by the first expansion device (110) to exchange heat with indoor air, and a four-way valve for controlling the circulation direction of the refrigerant discharged from the compressor (10). 50 and a refrigerant pipe 60 connecting these components and guiding the flow of the refrigerant.

And, one side of the indoor heat exchanger 20 and the outdoor heat exchanger 30, blowing fans 25 and 35 for blowing the fluid (air) that is heat-exchanged with the refrigerant is provided. The blowing fans 25 and 35 include an indoor fan 25 and an outdoor fan 35.

On the other hand, when the heating operation is performed under the control of the four-way valve 50, the circulation direction of the refrigerant is opposite to the refrigerant circulation direction in the heating operation described above. That is, after passing through the compressor 10 and the indoor heat exchanger 20, the refrigerant is expanded in the plurality of expansion devices 110 and 120 and evaporated in the outdoor heat exchanger 30.

The air conditioner 1 is provided with a phase separator 100 for separating the gaseous refrigerant from the refrigerant circulating in the heating operation.

The phase separator 100 is disposed at the outlet side of the indoor heat exchanger 20. In addition, a second expansion device 120 for expanding a refrigerant is provided at an inlet side of the phase separator 100. The refrigerant condensed in the indoor heat exchanger 20 is introduced into the phase separator 100 after the pressure is reduced in the second expansion device 120.

The refrigerant pipe 60 connecting the indoor heat exchanger 20 and the phase separator 100 is provided with a first branch 151 through which different flow paths are branched. The first branch unit 151 is connected to a suction passage 170 that guides the refrigerant to the phase separator 100 and a bypass passage 160 that bypasses the phase separator 100. The second expansion device 120 is provided in the suction flow path 170.

The bypass flow path 160 is provided with a first flow control device 141 for restricting the introduction of refrigerant into the bypass flow path 160 during the heating operation. That is, the refrigerant flows through the bypass flow path 160 only in the cooling operation and flows in the left direction of FIG. 2. The first flow regulating device 141 includes a check valve.

Inside the phase separator 100, a suction port 172 is provided to allow the refrigerant flowing along the suction flow path 170 to flow into the phase separator 100. The suction port 172 extends from the suction passage 170 and protrudes into the phase separator 100. In addition, the suction port 172 extends downwardly from the top surface of the phase separator 100, and thus the refrigerant flows into the bottom of the phase separator 100.

One side of the phase separator 100 is provided with a gas phase pipe 64 through which the gas phase refrigerant separated from the phase separator 100 is discharged. The gas phase pipe 64 extends upward from the top surface of the phase separator 100, and thus the gas phase refrigerant flows outwardly above the phase separator 100.

The gas phase pipe 64 is provided with a third expansion device 130 that is selectively openable so that the gaseous refrigerant can be injected into the compressor 10. The third expansion device 130 is disposed at the inlet side of the compressor 10. For example, the third expansion device 130 may be opened during a heating operation, and the third expansion device 140 may be closed during a cooling operation.

The other side of the phase separator 100 is provided with a liquid pipe 62 through which the liquid refrigerant separated from the phase separator 100 is discharged. The liquid pipe 62 extends downward from the bottom surface of the phase separator 100, and thus the liquid refrigerant flows downward outside the phase separator 100.

The liquid flow pipe 62 is provided with a second flow rate adjusting device 142 that allows the refrigerant to flow through the liquid pipe 62 only during the heating operation.

That is, during the cooling operation of the air conditioner, the second flow rate adjusting device 142 is closed, whereby the refrigerant is restricted from flowing into the liquid pipe 62. In addition, during the heating operation, the second flow control device 142 is opened so that the refrigerant flows upward in FIG. 2. The second flow control device 142 includes a check valve.

As such, since the gas phase pipe 64 extends above the phase separator 100 and the liquid pipe 62 extends below the phase separator 100, the gas phase refrigerant having a specific gravity lower than that of the liquid refrigerant may be It is easily discharged to the gas phase pipe 64 and the liquid refrigerant is discharged to the liquid pipe 62.

That is, the separation efficiency of the liquid refrigerant and the gaseous refrigerant is increased, thereby effectively injecting the compressor to improve the heating performance.

The air conditioner 1 is provided with a second branch 152 to which the liquid pipe 62 and the bypass flow path 160 are connected. In the heating operation, the refrigerant flows along the liquid pipe 62 and then flows into the first expansion device 110 through the second branch portion 152. In addition, the refrigerant may be depressurized by the first expansion device 110 and flow into the outdoor heat exchanger 30.

On the other hand, the refrigerant condensed in the outdoor heat exchanger 30 during the cooling operation is bypassed in the second branch unit 152 and flows into the indoor heat exchanger 20 without passing through the phase separator 100. . In this regard, it will be described below with reference to the drawings.

2 is a view showing a refrigerant flow in the phase separator according to an embodiment of the present invention. Referring to Figure 2, the flow of the refrigerant during the cooling operation and heating operation of the air conditioner (1) will be described.

First, during the heating operation of the air conditioner (solid arrow), the refrigerant is condensed in the indoor heat exchanger 20 and then flows from the first branch portion 151 to the suction passage 170. At this time, the first flow control device 141 is closed so that the refrigerant does not flow into the bypass flow path 160.

The refrigerant flowing through the suction passage 170 flows into the lower portion of the phase separator 100 through the suction port 172. The refrigerant introduced into the phase separator (100) is separated into a gaseous phase and a liquid phase refrigerant, and the separated gaseous phase refrigerant flows out of the outside of the phase separator (100) through the gas phase pipe (64). It flows out to the outside of the phase separator 100 through the liquid pipe 62.

The third expansion device 130 is opened, and the gaseous refrigerant is injected into the compressor 10 through the third expansion device 130.

The liquid refrigerant flows along the liquid pipe 64 and is introduced into the first expansion device 110 through the second branch portion 152. In addition, the liquid refrigerant may be expanded by the first expansion device 110 and then introduced into the outdoor heat exchanger 30 to be evaporated.

As such, during the heating operation, the refrigerant flows into the phase separator 100 to perform phase separation, and the separated gas phase refrigerant is injected into the compressor 10 to compensate for the amount of refrigerant circulated in the compressor.

During the cooling operation of the air conditioner (dashed arrow), the refrigerant is condensed in the outdoor heat exchanger 30 and then expanded in the first expansion device 110. The expanded refrigerant flows into the bypass flow path 160 from the second branch portion 152. At this time, since the first flow control device 141 is opened, the second flow control device 142 is closed, the refrigerant can be easily introduced into the bypass flow path (160).

The refrigerant flowing through the bypass flow path 160 flows into the refrigerant pipe 60 through the first branch unit 151 and is evaporated in the indoor heat exchanger 20. At this time, in order to prevent the refrigerant from flowing into the phase separator 100 from the first branch 151, the second expansion device 120 is full-closed.

On the other hand, since the refrigerant is not introduced into the phase separator 100 during the cooling operation, the injection action to the compressor 10 may be limited. Thus, the third expansion device 130 may be closed.

As such, during the cooling operation, the refrigerant is expanded in the first expansion device 110 and then bypasses the phase separator 100 and flows into the indoor heat exchanger 20, thereby passing through the phase separator 100. It is possible to prevent the additional pressure in the process. As a result, it is possible to prevent the pressure drop of the refrigerant to increase the system efficiency and increase the cooling capacity.

3 is a flow chart showing a control method of an air conditioner according to an embodiment of the present invention. 3, a control method of an air conditioner according to an embodiment of the present invention will be described.

As the air conditioner is turned on and operating conditions are input, the operation mode of the air conditioner is recognized. The operation mode may include a heating mode and a cooling mode (S11).

When the operating mode of the air conditioner is the cooling mode, the first expansion device 110 is opened, and the refrigerant condensed in the outdoor heat exchanger 30 is expanded in the first expansion device 110 and then the second expansion device. It flows to the branch part 152 (S12, S13).

The first flow control device 141 is opened and the second flow control device 142 is closed. Therefore, the refrigerant flows into the bypass flow path 160 from the second branch portion 152. That is, the refrigerant does not flow into the phase separator 100, but bypass flows to the outlet side of the phase separator 100 (S14, S15, S16).

The second expansion device 120 is closed. Therefore, the refrigerant flowing through the bypass flow path 160 does not flow from the first branch portion 151 to the suction flow path 170 but flows to the refrigerant pipe 60. The refrigerant flows along the refrigerant pipe 60 and is evaporated in the indoor heat exchanger 20 (S17).

As such, during the cooling operation, the refrigerant bypasses the phase separator 100 so as not to pass through the second expansion device 120, thereby preventing additional pressure drop of the refrigerant.

On the other hand, when the operation mode of the air conditioner is recognized as the heating mode in step S12, the second expansion device 120 is opened, the refrigerant flows from the first branch portion 151 to the suction flow path 170. And is expanded in the second expansion device (120). At this time, the first flow control device 141 may be closed or opened.

When the first flow control device 141 is closed, the refrigerant is restricted from flowing from the first branch portion 151 to the bypass flow path 160. On the other hand, even if the first flow control device 141 is open, the pressure of the first branch portion 151 is higher than the pressure of the second branch portion 152, the refrigerant is the first branch portion 151 Inflow into the bypass flow path 160 will be limited.

In summary, the bypass flow passage 160 may be understood as a flow passage extending from the first branch portion 151 to the second branch portion 152.

In addition, since the pressure in the second branch portion 152 is formed as low as the pressure reduced in the second expansion device 120 with respect to the pressure in the first branch portion 151, the bypass flow path 160 ), The flow from the second branch portion 152 to the first branch portion 151 will be limited (S21, S22).

The refrigerant flowing along the suction flow path 170 is introduced into the phase separator 100 through the suction port 172. The refrigerant is separated into a liquid refrigerant and a gaseous refrigerant in the phase separator 100 (S23).

The third expansion device 130 is opened, and the separated gaseous refrigerant passes through the third expansion device 130 through the gas phase pipe 64 and is injected into the compressor 10 (S24).

The second flow control device 142 is open, the separated liquid refrigerant is introduced into the second branch portion 152 through the liquid pipe (62). Then, the first expansion device 110 is opened, the refrigerant is expanded again while passing through the first expansion device 110 in the second branch 152, and evaporated in the outdoor heat exchanger (30). .

As described above, since the pressure of the second branch portion 152 is lower than the pressure of the first branch portion 151, the refrigerant flows from the second branch portion 152 into the bypass flow path 160. Can be limited (S25, S26).

As described above, since the refrigerant flows into the phase separator 100 to separate the gaseous refrigerant during the heating operation, and the separated gaseous refrigerant may be injected into the compressor, the heating performance may be improved.

1: air conditioner 10: compressor
20: indoor heat exchanger 28: indoor expansion device
30: outdoor heat exchanger 40: gas-liquid separator
50: four sides 60: refrigerant pipe
100: phase separator 110: first expansion device
120: second expansion device 130: third expansion device
141: first flow control device 142: second flow control device
151: first branch 152: second branch
160: bypass flow path 170: suction flow path

Claims (13)

In the air conditioner where the refrigeration cycle is driven and the operation mode can be switched,
A compressor for compressing the refrigerant;
A condenser for condensing the refrigerant compressed in the compressor;
A phase separator for separating the gaseous refrigerant from the refrigerant passing through the condenser;
A plurality of expansion devices provided on at least one side of the phase separator, for expanding the refrigerant flowing into the phase separator or the refrigerant flowing out of the phase separator; And
In one of the operation modes, the air conditioner includes a bypass flow path for bypassing the inlet-side refrigerant of the phase separator to the outlet side of the phase separator. The method of claim 1,
The bypass flow path further comprises a first flow control device for allowing the flow of the refrigerant only in the one mode. The method of claim 1,
The operation mode includes a cooling mode and a heating mode,
The one mode is the air conditioner, characterized in that the cooling mode. The method of claim 3, wherein
In the heating mode,
Refrigerant is introduced into the interior of the phase separator, the air conditioner is limited to flow into the bypass flow path. The method of claim 3, wherein
Based on the refrigerant flow direction in the heating mode,
A second expansion device disposed at an inlet side of the phase separator to primary expand the refrigerant; And
And a first expansion device disposed at an outlet side of the phase separator to expand second refrigerant. The method of claim 5, wherein
In the heating mode,
A liquid flow path through which the liquid refrigerant separated by the phase separator flows; And
The air conditioner is provided in the liquid flow path, the air conditioner further comprises a second flow control device for guiding the liquid refrigerant to the first expansion device. The method according to claim 6,
The liquid flow path is an air conditioner extending below the outside of the phase separator. The method of claim 5, wherein
In the cooling mode, the second expansion device is closed. The method according to claim 6,
At least one of the first flow regulating device and the second flow regulating device is a check valve. A refrigeration cycle comprising a compressor, a condenser, an expansion device, and an evaporator is driven, and a method for controlling an air conditioner including a phase separator for separating a gaseous refrigerant from the refrigerant passing through the condenser,
Recognizing an operation mode of the air conditioner;
Determining whether the refrigerant passing through the condenser is introduced into the phase separator according to the operation mode; And
If the operation mode is the first mode, the refrigerant passing through the condenser is bypassed to the outlet side of the phase separator,
And the refrigerant passing through the condenser is introduced into the phase separator when the operation mode is the second mode. 11. The method of claim 10,
If the driving mode is the first mode,
A first flow control device for operating the refrigerant passing through the condenser to the outlet side of the phase separator is operated,
And operating a second flow regulator for preventing the refrigerant passing through the condenser from entering the phase separator. 11. The method of claim 10,
If the driving mode is the second mode,
A second expansion device for primary expansion of the refrigerant passing through the condenser before entering the phase separator;
And operating a first expansion device for secondary expansion of the liquid refrigerant separated from the phase separator. 11. The method of claim 10,
And the first mode is a cooling mode, and the second mode is a heating mode.

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