KR20120122704A - An air conditioner and a control method the same - Google Patents

Abstract

PURPOSE: An air conditioner and control method thereof are provided to increase the amount of refrigerant flowing into a compressor as the refrigerant is additionally cooled in a second heat exchanger so that enough liquid refrigerant bypasses. CONSTITUTION: An air conditioner(1) comprises a compressor(10), a suction pipe, an indoor heat exchanger(20), an indoor expansion unit(28), a first heat exchanger(60), and a second heat exchanger(100). The indoor expansion unit decompresses the refrigerant condensed in the indoor heat exchanger. The first heat exchanger facilitates the heat exchange between the refrigerant passing through the expansion unit and the refrigerant flowing in the suction pipe. The second heat exchanger facilitates the heat exchange by bypassing a part of the refrigerant passing through the first heat exchanger. The refrigerant passing through the second heat exchanger flows into the compressor.

Description

Air conditioner and control method {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.

In general, when the air conditioner performs a heating operation, a large amount of system refrigerant circulating in the refrigeration cycle is required. In this case, an input date to be input in order to achieve sufficient heating capacity, that is, a large amount of refrigerant to be sucked in the compressor is required.

However, according to the conventional air conditioner, when the air conditioner performs the heating operation, due to the limited system capacity (capacity), the amount of refrigerant circulating in the refrigerating system, in particular, the amount of refrigerant sucked into the compressor appeared to be insufficient.

Accordingly, there is a problem that the system capacity does not meet the required heating conditions (for example, increase in the amount of heating airflow, cryogenic outdoor temperature, etc.), and eventually the air conditioner does not achieve sufficient heating capacity.

The present invention has been proposed to solve such a problem, and an object of the present invention is to provide an air conditioner in which a liquid refrigerant is introduced into a compressor to increase heating performance.

An air conditioner according to an embodiment of the present invention includes a compressor for compressing a refrigerant; A suction pipe guiding the introduction of the refrigerant into the compressor; An indoor heat exchanger configured to heat exchange the refrigerant discharged from the compressor; An indoor expansion device for reducing the refrigerant condensed in the indoor heat exchanger; A first heat exchanger configured to exchange heat between the refrigerant passing through the indoor expansion device and the refrigerant flowing through the suction pipe; And a second heat exchanger configured to bypass at least a portion of the refrigerant passing through the first heat exchanger to perform heat exchange, and the refrigerant passing through the second heat exchanger flows into the compressor.

According to another aspect, a control method of an air conditioner includes: an air conditioner including a compressor, an indoor heat exchanger, and an indoor expansion device, including: driving the compressor; Exchanging heat with a second refrigerant, wherein the first refrigerant of at least a portion of the refrigerant passing through the indoor expansion device is sucked into the compressor; Sensing the temperature of the refrigerant discharged from the compressor; Recognizing whether the discharge refrigerant temperature of the compressor has exceeded a set temperature; And reducing the flow rate of the first refrigerant when the discharge refrigerant temperature of the compressor exceeds the set temperature.

According to the present invention, it is possible to increase the amount of refrigerant circulating through the compressor by bypassing the refrigerant discharged from the outdoor heat exchanger and introducing the bypassed refrigerant into the compressor after heat-exchange in the first heat exchanger. Accordingly, there is an advantage that the heating ability can be improved.

In addition, since the refrigerant is additionally cooled in the second heat exchanger before being introduced into the first heat exchanger, sufficient liquid refrigerant may be bypassed, thereby increasing the amount of refrigerant flowing into the compressor.

In addition, the refrigerant discharged from the outdoor heat exchanger is partially bypassed and flows into the second heat exchanger. Since the amount of refrigerant bypassed by the flow control valve is controlled, the amount of heat exchange with the compressor suction refrigerant can be controlled. There is an effect that can prevent the rise.

In addition, since the amount of refrigerant bypassed by the second heat exchanger can be controlled, the capacity of the second heat exchanger for additionally cooling the refrigerant can be largely designed without concern about the rise of the refrigerant discharge temperature of the compressor, and accordingly, There is an effect that the liquid refrigerant can be introduced into the first heat exchanger.

1 is a system diagram showing the configuration of an air conditioner according to an embodiment of the present invention.
2 is a block diagram showing the configuration of an air conditioner according to an embodiment of the present invention.
3 is a flowchart illustrating a method of controlling an air conditioner 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.

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. Hereinafter, the configuration of the air conditioner will be described based on the heating operation.

The air conditioner 1 includes a compressor 10 for compressing a refrigerant, an indoor heat exchanger 20 for allowing the refrigerant compressed by the compressor 10 to exchange heat, and condensation in the indoor heat exchanger 20. Controls the circulation direction of the indoor expansion device 28 and the outdoor expansion device 38 for expanding the refrigerant, the outdoor heat exchanger 30 for allowing the expanded refrigerant to heat exchange, and the refrigerant discharged from the compressor 10. Four-way valve 40 for connecting to these configurations and the refrigerant pipe 50 for guiding the flow of the refrigerant is included.

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 cooling operation is performed under the control of the four-way valve 40, the refrigerant is the compressor 10, the outdoor heat exchanger 30, the outdoor expansion device 38, the indoor expansion device 28 and the indoor heat exchanger Cycle through 20.

When the air conditioner 1 performs the heating operation, a plurality of heat exchangers 60 and 100 are provided between the indoor heat exchanger 20 and the outdoor heat exchanger 30 based on the flow direction of the refrigerant.

The plurality of heat exchangers 60 and 100 may include a second heat exchanger 60 to allow at least some of the refrigerant injected into the compressor 10 to exchange heat among the refrigerant flowing through the refrigerant pipe 50.

The second heat exchanger 60, the third heat exchanger 61 and the third heat exchanger 61 for allowing the refrigerant flowing in the refrigerant pipe 50 to exchange heat, and the refrigerant pipe 50 A fourth heat exchanger 62 through which some of the refrigerant flowing through the refrigerant flows is included.

The third heat exchange part 61 or the fourth heat exchange part 62 may be understood as a part of the refrigerant pipe, or may be understood as a separate heat exchange member connected to the refrigerant pipe.

The refrigerant pipe 50 includes a second branch 71 to allow at least a portion of the refrigerant flowing through the refrigerant pipe 50 to be branched to the fourth heat exchange part 62.

In addition, the air conditioner 1 further includes a second branch pipe 77 extending from the second branch 71 to the compressor 10 to guide the flow of the refrigerant. The fourth heat exchange part 62 may be understood as at least a portion of the second branch pipe 77.

The refrigerant bypassed to the second branch pipe 77 is a liquid refrigerant, and when the amount of the liquid refrigerant is sufficiently secured, the effect of being injected into the compressor 10 may be increased.

The second branch pipe 77 is provided with an injection expansion device 65 for expanding the refrigerant branched from the second branch 71.

The refrigerant bypassed by the second branch part 71 is decompressed while passing through the injection expansion device 65, and obtains heat while exchanging heat with the third heat exchange part 61. When the refrigerant obtains the predetermined heat, the state of the refrigerant may reduce the proportion of the liquid phase.

The refrigerant passing through the fourth heat exchange part 62 is injected (injected) into the compressor 10 along the first branch pipe 77. The compressor 10 is provided with an injection port 13 through which the refrigerant bypassed from the refrigerant pipe 50 flows.

The second branch pipe 77 may be referred to as an “injection pipe” in that the bypassed refrigerant is injected into the compressor 10.

As such, since the refrigerant passing through the indoor heat exchanger 20 and the indoor expansion device 28 may be bypassed and introduced into the compressor 10, the refrigerant circulating through the compressor 10 may be increased. Accordingly, the heating performance can be improved.

Meanwhile, among the refrigerants flowing along the refrigerant pipe 50, the remaining refrigerant except the refrigerant bypassed to the fourth heat exchange part 62 passes through the third heat exchange part 61 to the outdoor expansion device 38. Can be introduced into.

The plurality of heat exchangers 60 and 100 are provided between the second heat exchanger 60 and the indoor expansion device 28 so that the refrigerant passing through the indoor expansion device 28 is further cooled. 100 is included.

The first heat exchanger 100 includes at least a portion of the first heat exchanger 101 and the compressor 10 and the suction pipe 15 to allow the refrigerant passing through the indoor expansion device 28 to bypass and exchange heat. The second heat exchanger 102 is included.

The first heat exchange part 101 or the second heat exchange part 102 may be understood as a part of the refrigerant pipe, or may be understood as a separate heat exchange member connected to the refrigerant pipe.

The refrigerant pipe 50 is provided with a first branch portion 73 for bypassing at least a portion of the refrigerant flowing through the first heat exchange part 101. The first branch pipe 79 extends from the first branch 73, and the first heat exchange part 101 forms a part of the first branch pipe 79.

The refrigerant pipe 50 is provided with a lamination part 75 to allow the first branch pipe 79 to be laminated on the refrigerant pipe 50.

As such, since the second branch pipe 77 and the first branch pipe 79 are pipes provided to bypass at least a portion of the refrigerant flowing through the refrigerant pipe 50, the refrigerant pipe 50 may be separated. The main branch pipe and the second branch pipe 77 and the first branch pipe 79 may be referred to as "branch pipe".

The refrigerant bypassed by the first branch unit 73 may be heat-exchanged with the refrigerant sucked into the compressor 10 through the first heat exchanger 100 to be cooled. As the bypass refrigerant is further cooled, the amount of liquid refrigerant can be increased. On the other hand, the suction refrigerant of the compressor 10 may be heated.

The refrigerant passing through the first heat exchanger 100 is laminated to the refrigerant pipe 50 at the lamination part 75. In addition, the liquid refrigerant laminated to the refrigerant pipe 50 may be bypassed to the injection expansion device 65 through the second branch pipe 77.

That is, the liquid refrigerant cooled and increased in the first heat exchanger 100 may be bypassed into the second branch pipe 77 to be injected into the compressor 10.

As such, the amount of the liquid refrigerant may be increased by the heat exchange action of the first heat exchanger 100, and the increased liquid refrigerant may be increased through the injection expansion device 65 and the fourth heat exchanger 62. ), The circulating refrigerant of the compressor 10 may be increased. Therefore, the heating capability of the air conditioner 1 can be improved.

The compressor 10 includes a suction port 11 for guiding the refrigerant sucked into the compressor 10 and a discharge port 12 for guiding the refrigerant discharged from the compressor 10.

The suction port 11 is connected to the suction pipe 15, and the refrigerant heat exchanged in the first heat exchanger 100 passes through the suction pipe 15 and the suction port 11 to the compressor 10. Can be introduced.

The first branch pipe 79 is provided with a flow rate controller 105 for controlling the amount of refrigerant bypassed to the first heat exchange unit 101. The flow control unit 105 may be a valve capable of adjusting the opening degree.

In the process of performing heat exchange between the first refrigerant bypassed by the first branch unit 73 and the second refrigerant flowing into the compressor 10, the temperature of the second refrigerant rises to increase the temperature of the compressor 10. There may be a problem that the discharge refrigerant temperature is excessively increased. When the discharge temperature of the compressor 10 is excessively high, the compressor 10 may be crowded, and the refrigeration efficiency may be lowered.

In this case, the flow rate adjusting unit 105 may be closed or its opening degree may be lowered. That is, the amount of the refrigerant flowing through the first heat exchange part 101 may be reduced, and accordingly, the heat transferred to the second heat exchange part 102 may be reduced.

Therefore, it is possible to reduce the temperature of the refrigerant sucked into the compressor 10 and, as a result, prevent the excessively increased discharge temperature of the compressor 10.

Other embodiments are suggested.

In FIG. 1, at least a portion of the refrigerant having passed through the indoor expansion device 28 has been described as being branched from the first branch 73 and introduced into the first heat exchanger 100.

Alternatively, however, the refrigerant having passed through the indoor expansion device 28 may be configured to be introduced into the first heat exchanger 100. In this case, the first branch portion 73 and the lamination portion 75 may be omitted.

Figure 2 is a block diagram showing the configuration of an air conditioner according to an embodiment of the present invention, Figure 3 is a flow chart showing a control method of the air conditioner according to an embodiment of the present invention.

2, in the air conditioner 1 according to the embodiment of the present invention, the operation unit 80 to input a predetermined command for the operation of the air conditioner 1, and the compressor 10 A discharge temperature sensor 85 for detecting the discharge temperature of the) is included. The operation unit 80 may be provided in the air conditioner 1 or the indoor unit.

In addition, the air conditioner 1 is based on values detected by the compressor 10 and the discharge temperature sensor 85 which are driven according to an operation command input of the air conditioner 1 through the operation unit 80. It includes a flow rate control unit 105 to adjust the opening degree.

Hereinafter, a control method of the air conditioner according to the present embodiment will be described with reference to FIG. 3.

The operation of the air conditioner 1 is started by the operation of the operation unit 80. When the operation of the air conditioner 1 starts, the compressor 10 is driven and the refrigerant cycle of the compression-condensation-expansion-evaporation process is driven (S11).

In addition, a condenser, that is, the refrigerant condensed in the indoor heat exchanger 20 passes through the indoor expansion device 28, and is heat-exchanged in the first heat exchanger 100 and the second heat exchanger 60, thereby providing the compressor 10. Is injected into the.

In addition, the flow rate control unit 105 may be opened. By opening the flow rate controller 105, the second heat exchanger 100 may exchange heat between the bypassed first refrigerant and the compressor 10 suction refrigerant (second refrigerant). Of course, the flow rate control unit 105 may be completely open, it may be opened in a predetermined opening (S13).

In the process of heat exchange in the first heat exchanger 100, the discharge temperature of the compressor 10 may be sensed by the discharge temperature sensor 85. The detection of the discharge temperature may be made during the operation of the air conditioner 1 (S14).

It is recognized whether the compressor discharge temperature has exceeded the set temperature. When the compressor discharge temperature exceeds the set temperature, the flow rate control unit 105 may be closed or the opening degree thereof may be reduced.

By controlling the opening degree of the flow rate control unit 105, the amount of bypass refrigerant (first refrigerant) that is bypassed to the first heat exchange unit 101 may be reduced. Therefore, since the heat exchange amount of the first heat exchanger 100 is reduced, the discharge temperature of the compressor 10 may be reduced (S16).

The opening degree control of the flow rate control unit 105 may be maintained until the discharge temperature of the compressor 10 decreases below the set temperature. When the discharge temperature of the compressor 10 is reduced below the set temperature, the flow rate adjusting unit 105 may be maintained at a set opening degree.

Here, the set opening degree may be an opening degree for allowing the first refrigerant to flow by a predetermined amount.

On the other hand, if the discharge temperature of the compressor 10 in step S15 does not exceed the set temperature, the open state of the flow control unit 105 in the step S13 is maintained, the steps of S13 and S14 can be repeated.

In this way, the flow rate control unit 105 is controlled according to the discharge temperature value of the compressor 10 to adjust the amount of the first refrigerant, that is, the amount of heat exchange in the first heat exchanger 100, Excessive increase in the discharge temperature of the compressor 10 can be prevented.

In addition, in order to increase the amount of the liquid refrigerant injected into the compressor 10 in a state in which the discharge temperature of the compressor 10 is prevented from being excessively increased by the adjustment of the flow rate adjusting unit 105, the The effect is that the capacity or capacity of the first heat exchanger 100 can be designed large.

1: air conditioner 10: compressor
20: indoor heat exchanger 28: indoor expansion device
30: outdoor heat exchanger 38: outdoor expansion device
50: refrigerant pipe 60: first heat exchanger
65: injection expansion device 71,73: first and second branch
75: lamination 77,79: branch 1,2 pipe
100: second heat exchanger 105: flow rate control unit

Claims (11)

A compressor for compressing the refrigerant;
A suction pipe guiding the introduction of the refrigerant into the compressor;
An indoor heat exchanger configured to heat exchange the refrigerant discharged from the compressor;
An indoor expansion device for reducing the refrigerant condensed in the indoor heat exchanger;
A first heat exchanger configured to exchange heat between the refrigerant passing through the indoor expansion device and the refrigerant flowing through the suction pipe; And
At least a portion of the refrigerant passing through the first heat exchanger is bypassed to include a second heat exchanger to perform heat exchange,
The refrigerant passing through the second heat exchanger is introduced into the compressor. The method of claim 1,
The air conditioner further comprises a flow rate adjusting unit for adjusting the amount of the refrigerant flowing into the first heat exchanger of the refrigerant passing through the indoor expansion device. The method of claim 1,
Further comprising a discharge temperature sensor for sensing the temperature of the refrigerant discharged from the compressor,
The opening degree of the flow rate adjusting unit is adjusted based on the value sensed by the discharge temperature sensor. The method of claim 3, wherein
And when the discharge temperature exceeds a set temperature, the opening degree of the flow rate control unit is reduced. The method of claim 1,
Refrigerant pipe further comprises a refrigerant flowing through the indoor expansion device,
The refrigerant pipe further comprises a first branch portion for allowing at least some of the refrigerant to be bypassed to the first heat exchanger. The method of claim 5, wherein
A second branch part provided in the refrigerant pipe and allowing at least some of the refrigerant to be bypassed to the second heat exchanger;
Branch piping extending from the second branch to the compressor; And
And an injection expansion device provided in the branch pipe and allowing the refrigerant bypassed in the second branch to expand. The method according to claim 6,
In the compressor,
A suction port for guiding the refrigerant flowing into the compressor;
A discharge port for guiding the refrigerant discharged from the compressor; And
And an injection port for guiding the refrigerant passing through the second heat exchanger into the compressor. In an air conditioner comprising a compressor, an indoor heat exchanger and an indoor expansion device,
Driving the compressor;
Exchanging heat with a second refrigerant, wherein the first refrigerant of at least a portion of the refrigerant passing through the indoor expansion device is sucked into the compressor;
Sensing the temperature of the refrigerant discharged from the compressor;
Recognizing whether the discharge refrigerant temperature of the compressor has exceeded a set temperature; And
If the discharge refrigerant temperature of the compressor exceeds the set temperature, reducing the flow rate of the first refrigerant. The method of claim 8,
And a first refrigerant exchanged with the second refrigerant is injected into the compressor. The method of claim 9,
And in the process of injecting the first refrigerant into the compressor, the first refrigerant is heat-exchanged after expansion. The method of claim 8,
Further comprising a flow rate control valve for adjusting the flow rate of the first refrigerant,
In the process of reducing the flow rate of the first refrigerant, the control method of the air conditioner, characterized in that the closing or opening is reduced.

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