KR100803145B1 - Air conditioner - Google Patents

Abstract

An air conditioner is provided to control an additional supercooling degree of an indoor unit, which is installed beyond a supercooling control range of a supercooling unit of an outdoor unit, by using a second supercooling unit, thereby minimizing refrigerant noise and capacity decrease resulted from the flashing phenomenon. An air conditioner includes at least an indoor unit(120a-120d) connected to an outdoor unit(110), a first supercooling unit for supercooling a refrigerant guided to the indoor unit from the outdoor unit, and a second supercooling unit(140) for supercooling a refrigerant guided to an indoor unit(120d) which is far located from the outdoor unit than a predetermined distance. The second supercooling unit is mounted to a first refrigerant pipe(150) which is farer than a predetermined distance, and has a second bypass pipe(142) branched from the first refrigerant pipe, a second expansion valve(144) mounted on the second bypass pipe for decompressing the refrigerant flowing through the second bypass pipe, and a second heat exchange part(146) for carrying out heat exchange between the refrigerants passing through second bypass pipe and the first refrigerant pipe.

Description

Air conditioner

1 is a P-H diagram showing a comparison between the case of not using and the supercooler

Figure 2 is a block diagram showing a refrigeration cycle of the air conditioner according to the present invention

3 is a configuration diagram of an air conditioner according to the present invention to which the second subcooling unit is applied;

4 is a cutaway perspective view of a first subcooling unit of an air conditioner according to the present invention;

5 is a configuration diagram of a second subcooling unit of the air conditioner according to the present invention.

6 is a P-H diagram of an air conditioner refrigeration cycle according to the present invention when the second subcooling unit is applied.

7A to 7D are diagrams illustrating various configurations of the air conditioner according to the present invention to which the second subcooling unit is applied.

** Description of symbols for the main parts of the drawing **

102: compressor 104: condenser

106: expansion valve 108: evaporator

110: outdoor unit 120: indoor unit

130: first subcooling unit 132a, 132b: first bypass pipe

134: first expansion valve 136: first heat exchanger

140: second subcooling unit 142: second bypass pipe

144: second expansion valve 146: second heat exchange unit

150: first refrigerant pipe 160: second refrigerant pipe

The present invention relates to an air conditioner, and more particularly, to an air conditioner capable of sufficiently securing supercooling during refrigerant flow, minimizing refrigerant noise and deterioration of capacity, and actively coping with design requirements.

In general, an air conditioner is a cooling / heating device installed in a space or a wall of an indoor space such as an office or a home to cool or heat a room, and is composed of a compressor-condenser-expansion valve-evaporator and constitutes a series of refrigeration cycles. .

In particular, the air conditioner is mainly an outdoor unit (sometimes called 'outside' or 'heat sink') installed outdoors, and an indoor unit (sometimes called 'indoor' or 'heat absorbing side') mainly installed inside a building. The outdoor unit is provided with a condenser (outdoor heat exchanger) and a compressor, and the indoor unit is provided with an evaporator (indoor heat exchanger).

As is well known, an air conditioner may be broadly divided into a separate type air conditioner in which the outdoor unit and the indoor unit are separately installed, and an integrated air conditioner in which the outdoor unit and the indoor unit are integrally installed.

Briefly looking at the series of operations of the refrigeration cycle implemented in the air conditioner, the high-temperature, high-pressure refrigerant gas compressed in the compressor (compressor) is converted into a liquid while heat exchange in the condenser (condensor).

The liquid refrigerant is then converted from a linear expansion valve (LEV) to a high pressure, low temperature liquid or high temperature, low pressure two-phase (gas, liquid) wet steam state, which is an evaporator. Inlet and evaporate.

On the other hand, a subcooler is used to increase the subcooling of the liquid refrigerant flowing out of the condenser. The subcooler increases the subcooling of the refrigerant to serve to maintain the state of the refrigerant flowing from the condenser to the indoor unit in the liquid phase.

The subcooler is guided and expanded by a subcooling expansion valve having a portion of the liquid refrigerant flowing out of the condenser and is expanded, and the subcooled refrigerant and the refrigerant flowing through the refrigerant pipe are heat-exchanged, thereby cooling the refrigerant flowing through the refrigerant pipe. It is a device to increase the degree.

The supercooler suppresses the flashing phenomenon of the refrigerant flowing from the outdoor unit to the indoor unit before the expansion valve due to pressure loss in the refrigerant pipe, and prevents the air conditioner from degrading. Operational stability can be secured. In addition, when the refrigerant phase changes in the vicinity of the expansion valve of the indoor unit, the noise that the refrigerant flows inside the indoor unit occurs, there is an effect of preventing such noise generation. This subcooler is mainly used for medium and large air conditioners.

FIG. 1 is a P-H diagram showing a case in which a supercooler is not used and a case in which the supercooler is used, where A is an outdoor heat exchanger, that is, a condenser is used without a subcooler, and B is a case where a supercooler is used. ΔP is the sum of the pressure loss in the refrigerant pipe due to friction and the pressure loss due to gravity.

As shown in FIG. 1, the proper supercooling degree must be secured by the subcooler so that the refrigerant can flow to the indoor unit without vaporization even if a pressure loss occurs on the refrigerant pipe.

However, the conventional subcooler is installed in the outdoor unit, so it is not a problem when it is necessary to secure the subcooling even to a plurality of indoor units that are close to the outdoor unit, but when there is an indoor unit that is separated from the outdoor unit by a certain distance, excessive supercooling Because it must be secured, the bypass flow rate for this is increased, and eventually there is a problem that the loss of the entire system becomes larger than necessary.

In addition, since the capacity of the heat exchanger used in the supercooler varies according to the distance difference, there is a disadvantage in that the unity is difficult to mass-produce in the outdoor unit.

The present invention is to solve the above-mentioned problems, to provide a sufficient air conditioning during refrigerant flow to minimize the refrigerant noise and reduced capacity, and to provide an air conditioner that can actively respond to the design requirements.

In order to achieve the above object, the present invention provides an outdoor unit, at least one indoor unit connected to the outdoor unit, a first subcooling unit for supercooling the refrigerant guided from the outdoor unit to the indoor unit, and a predetermined distance from the outdoor unit. Provided is an air conditioner including a second subcooling unit for additionally supercooling a refrigerant guided to an indoor unit installed remotely.

The first subcooling unit may be installed in the outdoor unit, the first bypass pipe branched from the first refrigerant pipe guiding the refrigerant from the outdoor unit to the indoor unit, and provided on the first bypass pipe. The first expansion valve for depressurizing the refrigerant flowing through the first bypass pipe, and the first heat exchange unit for performing heat exchange between the refrigerant flowing through the first bypass pipe and the first refrigerant pipe. In addition, the first bypass pipe is preferably in communication with the compressor suction side of the outdoor unit.

The second subcooling unit may be provided on the first refrigerant pipe, which is farther away from the predetermined distance, and is provided on the second bypass pipe and the second bypass pipe branched from the first refrigerant pipe. And a second heat exchanger configured to exchange heat between the second expansion valve for depressurizing the refrigerant flowing through the second bypass pipe and the refrigerant flowing through the second bypass pipe and the first refrigerant pipe.

Here, the second expansion valve may be made of a thermal expansion valve, the second bypass pipe is preferably in communication with the second refrigerant pipe for guiding the refrigerant from the indoor unit to the outdoor unit.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the present invention to those skilled in the art. Like numbers refer to like elements throughout.

Figure 2 is a block diagram showing a refrigeration cycle of the air conditioner according to the present invention. 3 is a configuration diagram of an air conditioner according to the present invention to which the second subcooling unit is applied, and FIG. 4 is a cutaway perspective view of a first subcooling unit of the air conditioner according to the present invention, and FIG. 5 is an air conditioner according to the present invention. It is a block diagram of the 2nd subcooling unit of group.

2 to 5, the air conditioner according to the present invention is an outdoor unit 110 and at least one indoor unit 120a, 120b, 120c, 120d connected to the outdoor unit 110, hereinafter referred to as 120). And a first subcooling unit 130 for subcooling the refrigerant guided from the outdoor unit 110 to the indoor unit 120, and an indoor unit 120 installed farther from the outdoor unit 110 than a predetermined distance. And a second subcooling unit 140 for further subcooling the refrigerant.

The air conditioner may include components that constitute a general refrigeration cycle. As shown in FIG. 2, first, a compressor 102 that sucks gaseous refrigerant and compresses the gas into a high temperature and a high pressure is provided. The compressor 102 increases the pressure of the gaseous refrigerant so that it can be liquefied even at a relatively high temperature, and provides power to circulate between the components constituting the refrigeration cycle.

The gaseous refrigerant compressed by the compressor 102 undergoes heat exchange while passing through the condenser 102 to liquefy the heat, becoming a medium-temperature, high-pressure liquid refrigerant. Here, the working fluid which heat exchanges with the refrigerant may be air or cooling water. Through the heat exchange with the working fluid, the refrigerant begins to liquefy and becomes a fully condensed liquid state through a mixture of vapor and liquid.

The refrigerant liquefied in the condenser 102 is introduced into the expansion valve 106. Here, the expansion valve 106 may be a linear expansion valve (LEV). The linear expansion valve is a valve for linearly adjusting the refrigerant flow rate of the evaporator 108 by an electronic controller. Linear expansion valves have been used in recent years because they can reduce energy use by applying to long operating time and large load fluctuations.

The expansion valve 106 serves to lower the pressure of the refrigerant. This is because the refrigerant must be lowered in order to easily evaporate, and if the pressure is not lowered, the liquid refrigerant will not be easily evaporated. In conclusion, the expansion valve 106 reduces the refrigerant introduced from the condenser 102 so that the liquid refrigerant can be easily evaporated at a relatively high temperature. In addition, the expansion valve 106 also serves to supply a proper amount to the evaporator 108 by adjusting the flow rate of the refrigerant.

The liquid refrigerant flowing out of the expansion valve 106 is in a state of wet steam that is almost like water vapor spraying. The refrigerant in the wet vapor state enters the evaporator 108 to absorb the heat around the evaporation occurs to change into a gas. That is, the low-temperature, low-pressure liquid refrigerant flowing into the evaporator 108 from the expansion valve 106 is evaporated while exchanging heat with the indoor air, and as a result, the cooling effect of lowering room temperature is exerted.

Between the expansion valve 106 and the evaporator 108 is provided with a silencer 150 that serves to reduce the flow noise due to abnormal flow. The inlet, the body, and the outlet of the muffler 109 form a main flow path (not shown) having the same diameter. In the main passage, splitting means (not shown) having a predetermined length in the same direction as the refrigerant flow direction are provided so that large bubbles of the refrigerant flowing through the main passage are divided and flowed.

Meanwhile, the refrigerant flowing out of the evaporator 108 flows back into the compressor 102 and circulates repeatedly doing the same work.

Here, the air conditioner is composed of a compressor 102, an outdoor unit 110 having a condenser 102, and an indoor unit 120 having an expansion valve 106 and an evaporator 108 to perform only cooling of an indoor space. It can be made to.

In addition, the air conditioner is the expansion valve 106 is provided in both the outdoor unit 110 and the indoor unit 120, and is provided with a flow path switching valve (not shown) to be configured to perform both cooling and heating of the indoor space Can be. In this case, an indoor heat exchanger (not shown) is provided in the indoor unit 120, and an outdoor heat exchanger (not shown) is provided in the outdoor unit 110, respectively, depending on whether the indoor space is cooled or heated. Serves as evaporator 108.

As shown in FIG. 3, a multi air conditioner in which a plurality of indoor units 120 are connected to the outdoor unit 110 may be assumed. Recently, a multi air conditioner in which a plurality of indoor units 120 are connected to a plurality of outdoor units 110 is also widely used.

Meanwhile, the air conditioner according to the present invention may further include a first subcooling unit 130 for subcooling the refrigerant guided from the outdoor unit 110 to the indoor unit 120.

The first subcooling unit 130 is installed in the outdoor unit 110 and serves to supercool the refrigerant flowing out of the condenser 102.

Specifically, the first subcooling unit 130, the first bypass pipe (132a, 132b) branched from the first refrigerant pipe 150 for guiding the refrigerant from the outdoor unit 110 to the indoor unit, and the first A first expansion valve 134 provided on the bypass pipes 132a and 132b for reducing the refrigerant flowing through the first bypass pipes 132a and 132b, and the first bypass pipes 132a and 132b; ) And a first heat exchanger 136 that performs heat exchange between the refrigerant flowing through the first refrigerant pipe 150.

An example of the configuration and operation of the first subcooling unit 130 will be described with reference to FIG. 3.

First, the suction side first bypass pipe 132a is branched from the first refrigerant pipe 150. A portion of the liquid refrigerant flowing through the first refrigerant pipe 150 through the suction side first bypass pipe 132a flows into the first expansion valve 134.

The refrigerant introduced into the first expansion valve 134 is decompressed while expanding, and the reduced pressure refrigerant exchanges heat with the refrigerant flowing through the first refrigerant pipe 150 in the first heat exchanger 136 to evaporate. Therefore, the refrigerant flowing through the first refrigerant pipe 150 in the first heat exchange part 136 is decooled by being deprived of heat.

The first heat exchange part 136 is configured to form an outer pipe surrounding the first refrigerant pipe 150, the first refrigerant pipe 150 passing through the first heat exchange unit 136 is a spiral tube type It is composed. This is to increase the contact area of the refrigerant to improve the cooling efficiency.

A discharge side first bypass pipe 132b is provided at one side of the first heat exchanger 136, and the discharge side first bypass pipe 132b is a suction side of the compressor 102 inside the outdoor unit 110. Communicating with Therefore, the refrigerant that is heat exchanged with the refrigerant flowing through the first refrigerant pipe 150 in the first heat exchange part 136 and vaporized, exits the first heat exchange part 136 and is discharged to the first bypass pipe 132b. The compressor 102 is guided to the suction side and compressed.

Meanwhile, the air conditioner according to the present invention may further include a second subcooling unit 140 for additionally supercooling the refrigerant guided to the indoor unit 120 installed farther from the outdoor unit 110 than a predetermined distance.

The first subcooling unit 130 is installed in the outdoor unit 110 to control the basic subcooling, to control the indoor unit 120 connected within a predetermined distance from the outdoor unit 110, the indoor unit installed farther than the predetermined distance For 120, the second subcooling unit 140 is installed to control the degree of subcooling. Here, the predetermined distance will be the distance that the liquid refrigerant can be delivered to the indoor unit 120 without a flashing phenomenon by the subcooling control of the first subcooling unit 130, and includes a height difference.

Here, the second subcooling unit 140 is not installed in the outdoor unit 110, but is provided on the first refrigerant pipe 150 farther than the predetermined distance.

Specifically, the second subcooling unit 140 is provided on the second bypass pipe 142 and the second bypass pipe 142 branched from the first refrigerant pipe 150. Second heat exchange between the second expansion valve 144 for reducing the refrigerant flowing through the bypass tube 142 and the refrigerant flowing through the second bypass tube 142 and the first refrigerant pipe 150 It may include a portion 146.

2 and 4, an example of the configuration and operation of the second subcooling unit 140 will be described.

First, the second bypass pipe 142 is branched from the first refrigerant pipe 150. A portion of the liquid refrigerant flowing through the first refrigerant pipe 150 through the second bypass pipe 142 flows into the second expansion valve 144.

Here, the second expansion valve 144 may be made of a thermal expansion valve (TXV).

The thermal expansion valve is a type of mechanical expansion valve, and a thermostat (not shown) senses the temperature at the suction side to control the flow of the liquid refrigerant. Thermal expansion valves are widely used because they are inexpensive, easy to attach, and rarely malfunction. In particular, the linear expansion valve is mainly used as an expansion valve of a large-capacity air conditioner, and since the price is relatively expensive, the expansion valve used in the second subcooling unit 140 is preferably a thermal expansion valve.

The refrigerant introduced into the second expansion valve 144 expands and is decompressed, and the reduced pressure evaporates while exchanging heat with the refrigerant flowing through the first refrigerant pipe 150 in the second heat exchanger 146. Therefore, the refrigerant passing through the first refrigerant pipe 150 in the second heat exchange part 146 is decooled by losing heat.

At this time, the second heat exchanger 146 may be a plate heat exchanger having a variable capacity and a small installation volume.

The second bypass pipe 142 communicates with the second refrigerant pipe 160 that guides the refrigerant from the indoor unit 120 to the outdoor unit. Therefore, the refrigerant evaporated in the second heat exchange part 146 is guided and compressed to the suction side of the compressor 102 through the second bypass pipe 142 and the second refrigerant pipe 160.

Figure 6 shows the P-H diagram of the air conditioner refrigeration cycle according to the present invention when the second subcooling unit is applied.

As shown in FIG. 6, when the second subcooling unit 140 is provided to prevent insufficient flashing by additionally securing insufficient subcooling, the first subcooling unit 130 does not have to excessively secure the subcooling on the high pressure side. Therefore, there is an advantage that can minimize the capacity degradation.

That is, the first subcooling unit 130 catches the subcooling degree of about 1-2 sections, and the second subcooling unit 140 additionally subcools the section 3-4 in a state where the pressure is lowered to some extent by the pressure loss of the pipe. It will catch the road.

7A to 7D are diagrams illustrating various configurations of the air conditioner according to the present invention to which the second subcooling unit is applied.

The indoor unit 120 from the outdoor unit 110 to the indoor unit 120 within a predetermined height d1 is covered by the subcooling control of the first subcooling unit 130, and the second indoor unit 120 is located at a height d2 above. By the subcooling unit 140 to secure the subcooling degree of the refrigerant, it is possible to prevent the flashing phenomenon. Here, the d1, that is, the predetermined height may be composed of a design value of the base product 40m, d2 is a height that varies depending on the height of the building or the number of floors. Of course, the specific numerical value can be changed, it is understood that it can also be used as a value representing the distance difference.

In addition, since the second subcooling unit 140 is provided, the first subcooling unit 130 of the outdoor unit 110 may be designed to have a capacity capable of ensuring a constant subcooling degree, thereby providing uniformity in manufacturing the outdoor unit 110. And mass production is improved, there is an advantage that can meet a variety of design requirements.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art to various modifications and changes to the present invention without departing from the spirit and scope of the invention described in the claims described below You can do it. Therefore, it should be seen that all modifications included in the technical scope of the present invention are basically included in the scope of the claims of the present invention.

According to the air conditioner according to the present invention has the following effects.

First, in the existing medium and large air conditioners, when the height difference is to be extended, the capacity of the supercooler installed in the outdoor unit increases, thereby overcoming the disadvantage that the capacity decreases.

Second, because it can catch the additional subcooling to the indoor unit installed outside the subcooling control range of the subcooler installed in the outdoor unit, it is possible to minimize the refrigerant noise and capacity degradation due to the flashign phenomenon.

Third, there is an advantage that can improve the unity and mass production of outdoor unit manufacturing, and can meet a variety of design requirements.

Claims (8)

Outdoor unit; At least one indoor unit connected to the outdoor unit; A first subcooling unit for subcooling the refrigerant guided from the outdoor unit to the indoor unit; And And a second subcooling unit for additionally supercooling a refrigerant guided to an indoor unit installed farther than a predetermined distance from the outdoor unit. The method of claim 1, The first sub-cooling unit is installed in the outdoor unit air conditioner. The method of claim 2, The first subcooling unit, A first bypass pipe branched from the first refrigerant pipe guiding the refrigerant from the outdoor unit to the indoor unit; A first expansion valve provided on the first bypass pipe and configured to reduce the refrigerant flowing through the first bypass pipe; And a first heat exchanger configured to exchange heat between the refrigerant flowing through the first bypass pipe and the first refrigerant pipe. The method of claim 3, wherein And the first bypass pipe communicates with a compressor suction side of the outdoor unit. The method according to claim 3 or 4, The second subcooling unit, Air conditioner, characterized in that provided on the first refrigerant pipe farther than the predetermined distance. The method of claim 5, wherein The second subcooling unit, A second bypass pipe branched from the first refrigerant pipe, A second expansion valve provided on the second bypass pipe and configured to reduce the refrigerant flowing through the second bypass pipe; And a second heat exchanger configured to perform heat exchange between the second bypass pipe and the refrigerant flowing through the first refrigerant pipe. The method of claim 6, And the second expansion valve is a thermal expansion valve. The method of claim 7, wherein The second bypass pipe, And a second refrigerant pipe communicating with the refrigerant from the indoor unit to the outdoor unit.

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