KR20240039436A - An air conditioner to perform a refrigerant injection into a compressor - Google Patents

Abstract

The present invention relates to an air conditioner that performs refrigerant injection into a compressor.
According to the present invention, it is possible to improve the separation efficiency of liquid refrigerant and gaseous refrigerant in the subcooler, reduce the discharge temperature of the compressor and improve operating efficiency through refrigerant injection into the compressor.
A flow path is configured to allow refrigerant separation at the front and rear ends of the supercooler, and the gaseous refrigerant separated or phase changed in the flow path is injected into the compressor, so the amount of injected refrigerant can be increased.

Description

An air conditioner to perform a refrigerant injection into a compressor}

The present invention relates to an air conditioner that performs refrigerant injection into a compressor.

An air conditioner is a device that maintains the air in a given space in the most suitable condition according to the use and purpose. Generally, the air conditioner includes a compressor, a condenser, an expansion device, and an evaporator, and operates a refrigeration cycle that performs the compression, condensation, expansion, and evaporation processes of the refrigerant, thereby cooling or heating the predetermined space. .

The predetermined space may be proposed in various ways depending on the location where the air conditioner is used. For example, when the air conditioner is placed in a home or office, the predetermined space may be an indoor space of the house or building. On the other hand, when the air conditioner is placed in a car, the predetermined space may be a boarding space for people.

When the air conditioner performs a cooling operation, the outdoor heat exchanger provided in the outdoor unit functions as a condenser, and the indoor heat exchanger provided in the indoor unit functions as an evaporator. On the other hand, when the air conditioner performs a heating operation, the indoor heat exchanger functions as a condenser and the outdoor heat exchanger functions as an evaporator.

Meanwhile, the air conditioner may further include an internal heat exchanger that performs heat exchange between the high-pressure refrigerant condensed in the condenser and the low-pressure refrigerant obtained by decompressing the condensed refrigerant. During the refrigerant heat exchange process in the internal heat exchanger, the low-pressure refrigerant absorbs heat and is vaporized, and the vaporized refrigerant can be injected into the compressor.

This refrigerant injection has the advantage of increasing the flow rate of the condenser when performing heating in a low-temperature environment and preventing pressure loss in the evaporator by reducing the amount of refrigerant flowing into the evaporator.

The amount of refrigerant (hereinafter referred to as injection refrigerant) injected into the compressor can be adjusted by the opening degree of the injection expansion device. When the opening degree of the injection expansion device is reduced, the amount of the injected refrigerant decreases, thereby increasing the superheating degree of the injected refrigerant. Conversely, when the opening degree of the injection expansion device increases, the amount of the injected refrigerant increases, thereby increasing the amount of the injected refrigerant. The degree of superheat can be reduced.

In the past, when the separation efficiency of gaseous refrigerant and liquid refrigerant was not good in the internal heat exchanger, there was a problem that the liquid refrigerant was injected into the compressor, deteriorating the reliability of the compressor.

Meanwhile, in order to solve this problem, when the opening degree of the injection expansion device is reduced to increase the superheat of the injection refrigerant, the amount of injected refrigerant is reduced and the discharge temperature of the compressor increases, which has the disadvantage of lowering operating efficiency.

1. Registered Patent 10-1639514 (Registration date: July 7, 2016) 2. Name of invention: Air conditioner

In order to solve the above problems, the present invention provides an air conditioner that improves the separation efficiency of liquid refrigerant and gaseous refrigerant in a supercooler, reduces the discharge temperature of the compressor and improves operating efficiency through refrigerant injection into the compressor. The purpose is to provide

The purpose of the present invention is to provide an air conditioner capable of configuring a flow path to enable refrigerant separation at the front and rear ends of a supercooler.

The present invention forms a branch at the front end of the supercooler, and consists of a first branch pipe extending to a higher position relative to the direction of gravity with respect to the branch and a second branch pipe extending to a lower position than the first branch pipe. The purpose is to provide an air conditioner that facilitates separation of gaseous refrigerant from refrigerant.

The purpose of the present invention is to provide an air conditioner having a T-shaped or Y-shaped pipe at the front of the supercooler to facilitate phase separation of the refrigerant.

The purpose of the present invention is to provide an air conditioner in which the branch part is formed between a supercooler and an expansion device, and the two-phase refrigerant decompressed in the expansion device flows into the branch part to cause phase separation.

The purpose of the present invention is to provide an air conditioner that can improve refrigerant injection efficiency by injecting gaseous refrigerant phase-separated at the front and rear ends of the subcooler into the suction end or middle stage of the compressor.

The purpose of the present invention is to provide an air conditioner that can improve heat exchange efficiency in a subcooler, including a subcooler having a double pipe heat exchange structure.

The purpose of the present invention is to provide an air conditioner capable of controlling the amount of refrigerant flowing through the injection pipe by installing a control valve on the injection pipe that extends from the outlet of the branch or subcooler to the compressor and guides the injection of the refrigerant. .

An air conditioner according to an embodiment of the present invention may include a subcooler in which heat exchange is performed between a condensation pipe and a supercooling pipe connected to the outlet side of the condenser. The supercooling pipe may be branched from the first branch of the condensation pipe and connected to the supercooler.

A supercooling expansion valve is installed in the supercooling pipe to depressurize the liquid refrigerant branched from the first branch, and inside the supercooler, the main refrigerant condensed in the condenser, that is, the refrigerant flowing through the condensation pipe and the main refrigerant A portion of the refrigerant may be branched to allow heat exchange between the branch refrigerant decompressed in the supercooled expansion valve, that is, the refrigerant flowing through the supercooled pipe.

Based on the supercooling pipe, a first injection pipe may be provided at the rear end of the supercooler for injecting the gaseous refrigerant that has undergone heat exchange in the supercooler and changed phase into the compressor.

The first injection pipe may be connected from the supercooler to the suction end or middle end of the compressor.

The supercooling pipe may include a second branch connected to the second injection pipe to inject refrigerant into the compressor.

The second branch may be disposed at the front of the supercooler.

The second branch may be formed between the supercooled expansion valve and the inlet side of the supercooler.

The second injection pipe may be connected to the suction end or middle end of the compressor in the second branch part.

A main expansion valve for reducing the pressure of the main refrigerant may be installed at the inlet side of the evaporator. The main expansion valve may be installed between the first branch and the evaporator.

The supercooling pipe includes a first branch pipe extending to the supercooler and a second branch pipe that is divided from the first branch pipe at a second branch portion and is formed at a higher position than the first branch pipe based on the direction of gravity, Phase separation may be achieved such that liquid refrigerant flows in the first branch pipe and gaseous refrigerant flows in the second branch pipe.

The second branch pipe may be connected to the second injection pipe.

The supercooling pipe may include a T-shaped pipe forming the first and second branch pipes.

The first and second branch pipes may extend orthogonally from the second branch portion.

The second branch pipe may extend from the second branch portion to form an acute angle less than 90 degrees with respect to the first branch pipe.

The subcooler may include an outer tube through which a main refrigerant flows and an inner tube provided inside the outer tube through which a branch refrigerant flows.

The supercooled piping includes a first piping part connected to the front end of the supercooling expansion valve and a second piping part connected to the rear end of the supercooling expansion valve and extending to the supercooler, and the diameter of the second piping part is the diameter of the first piping part. It can be formed larger.

The second piping part may include a valve connection pipe connected to the outlet side of the supercooled expansion valve and a first branch pipe bent from the valve connection pipe and extending to the supercooler.

The second piping unit may further include a second branch pipe that is divided from the first branch pipe at the second branch portion.

The valve connector and the second branch pipe are each connected to the first branch pipe and extend in the same direction, and the valve connector and the second branch pipe are spaced apart by a set length (L1) to form a laminar flow. There is a need.

A first control valve for controlling the amount of injected refrigerant may be installed in the first injection pipe extending from the supercooler to the compressor.

A first control valve for controlling the amount of injected refrigerant may be installed in the first injection pipe extending from the supercooler to the compressor.

A second control valve for controlling the amount of injected refrigerant may be installed in the second injection pipe extending from the second branch to the compressor.

Depending on whether the first and second control valves are turned on or off, the amount of refrigerant injected into the compressor can be adjusted.

In one aspect of the present invention, an air conditioner includes a compressor including first and second ports and a condenser for condensing the refrigerant compressed in the compressor; a main expansion valve provided on the outlet side of the condenser; an evaporator that evaporates the refrigerant reduced in pressure from the main expansion valve; a condensation pipe connecting the condenser and the evaporator and forming a first branch; a supercooling pipe branched from the first branch; a subcooler that performs heat exchange between the main refrigerant flowing in the condensation pipe and the branch refrigerant flowing in the supercooling pipe; and a supercooling expansion valve installed in the supercooling pipe and disposed on an inlet side of the supercooler.

The air conditioner includes a second branch formed on an outlet side of the supercooled expansion valve; a first injection pipe connected to the supercooling pipe at an outlet side of the subcooler and injecting the refrigerant heat exchanged in the supercooler into a first port of the compressor; And it may further include a second injection pipe branched from the second branch portion and through which gaseous refrigerant among the refrigerant decompressed in the supercooled expansion valve flows and is injected into the second port of the compressor.

The second branch is formed on the inlet side of the supercooler, and the supercooled expansion valve is configured to allow the refrigerant decompressed in the supercooled expansion valve to flow from the second branch to the second injection pipe. It may be installed at a point between the branch and the second branch.

The supercooling pipe may include a first branch pipe and a second branch pipe so that the phase separation of the refrigerant from the gaseous refrigerant to be introduced from the second branch into the second injection pipe is to the liquid refrigerant to be introduced to the supercooler. .

The second branch pipe is positioned at the first injection pipe with respect to the ground so that the gaseous refrigerant flows into the second injection pipe through the second branch pipe and the liquid refrigerant flows into the supercooler through the first branch pipe. It can be placed in a higher position than the branch pipe.

Based on the ground, the height (H2) of the connection end where the second branch pipe is connected to the second injection pipe will be greater than the height (H1) of the connection end where the first branch pipe is connected to the supercooler. You can.

The second branch pipe may extend upward from the first branch pipe in the opposite direction of the ground in the second branch portion.

The supercooling pipe may include a T-shaped pipe so that the second branch pipe is perpendicular to the first branch pipe.

The supercooling pipe may include a Y-shaped pipe so that the angle formed by the second branch pipe with respect to the first branch pipe forms an acute angle.

The supercooled piping includes a first piping portion connected to an inlet side of the supercooling expansion valve and a second piping portion connected to an outlet side of the supercooling expansion valve, and the second piping portion extends downward toward the ground. It may include a part and a second part bent and extended from the first part.

The second part may extend parallel to the ground so that the first part and the second branch pipe can be spaced apart by a set distance.

In order to form a stratified flow of refrigerant in the second branch, the opening degree of the supercooling expansion valve can be adjusted in a range where the mass flow rate of the refrigerant flowing through the supercooling pipe is up to 250 kg/m2*s. .

The first port may be one of the suction port and injection port of the compressor, and the second port may be the other one of the suction port and injection port of the compressor.

A control valve for controlling the amount of injected refrigerant may be installed in at least one of the first and second injection pipes.

According to the present invention, it is possible to improve the separation efficiency of liquid refrigerant and gaseous refrigerant in the subcooler, reduce the discharge temperature of the compressor and improve operating efficiency through refrigerant injection into the compressor.

According to the present invention, the flow path is configured so that refrigerant separation can be performed at the front and rear ends of the subcooler, and the gaseous refrigerant separated or phase changed in the flow path is injected into the compressor, so the amount of injected refrigerant can be increased.

According to the present invention, a branch is formed at the front of the supercooler, and a first branch pipe extends to a higher position relative to the direction of gravity with respect to the branch and a second branch pipe extends to a lower position than the first branch pipe. By configuring, it can be easy to separate the gaseous refrigerant from the refrigerant.

According to the present invention, a T-shaped pipe is provided at the front of the supercooler, so that phase separation of the refrigerant can be easily performed.

According to the present invention, by forming the branch between the supercooler and the expansion device, the two-phase refrigerant depressurized in the expansion device can flow into the branch and easily undergo phase separation.

According to the present invention, the injection efficiency of the refrigerant can be improved by injecting the gaseous refrigerant phase-separated at the front and rear ends of the subcooler into the suction end or middle stage of the compressor.

According to the present invention, heat exchange efficiency in a subcooler, including a subcooler having a double pipe heat exchange structure, can be improved.

According to the present invention, the amount of refrigerant flowing through the injection pipe can be easily adjusted by installing a control valve on the injection pipe that extends from the outlet of the branch or supercooler to the compressor and guides injection of the refrigerant.

1 is a refrigeration cycle diagram showing the configuration of an air conditioner according to a first embodiment of the present invention.
Figure 2 is a cycle diagram showing the subcooler and its surrounding configuration of an air conditioner according to the first embodiment of the present invention.
Figure 3 is a cross-sectional view showing the internal structure of a supercooler according to the first embodiment of the present invention.
Figure 4 is a diagram showing a first example of the connection structure of a supercooled pipe and a supercooled expansion valve according to the first embodiment of the present invention.
Figure 5a is a graph showing the laminar flow conditions required for easy separation of gaseous refrigerant and liquid refrigerant.
Figure 5b is a schematic diagram showing stratiform flow and other flows in contrast to the stratiform flow.
Figure 6 is a diagram showing a second example of the connection structure of the supercooling pipe and the supercooling expansion valve according to the first embodiment of the present invention.
Figure 7 is a refrigeration cycle diagram showing the configuration of an air conditioner according to a second embodiment of the present invention.
Figure 8 is a refrigeration cycle diagram showing the configuration of an air conditioner according to a third embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through illustrative drawings. When adding reference numerals to components in each drawing, it should be noted that identical components are given the same reference numerals as much as possible even if they are shown in different drawings. Additionally, when describing embodiments of the present invention, if detailed descriptions of related known configurations or functions are judged to impede understanding of the embodiments of the present invention, the detailed descriptions will be omitted.

Additionally, in describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, or order of the component is not limited by the term. When a component is described as being "connected," "coupled," or "connected" to another component, that component may be directly connected or connected to that other component, but there is no need for another component between each component. It should be understood that may be “connected,” “combined,” or “connected.”

Figure 1 is a refrigeration cycle diagram showing the configuration of an air conditioner according to a first embodiment of the present invention, and Figure 2 is a cycle diagram showing a supercooler and its surrounding configuration of an air conditioner according to a first embodiment of the present invention. , and Figure 3 is a cross-sectional view showing the internal structure of the supercooler according to the first embodiment of the present invention.

Referring to FIG. 1, the air conditioner 10 according to the first embodiment of the present invention is provided with a compressor 100 for compressing refrigerant and a suction side of the compressor 100 to mix a gaseous refrigerant and a liquid refrigerant among the refrigerants. It may include a gas-liquid separator 150 for separation. The gaseous refrigerant separated in the gas-liquid separator 150 may be sucked into the suction port 101 of the compressor 100.

The air conditioner 10 may include a suction pipe 20 connected to the suction side of the compressor 100. The gas-liquid separator 150 is installed in the suction pipe 20, and the suction pipe 20 may be connected to the suction port 101 of the compressor 100.

The suction pipe 20 may be understood as a pipe connected to the outlet side of the evaporator 140 and extending to the suction port 101 of the compressor 100.

The air conditioner 10 is provided on the outlet side of the compressor 100 and may include a flow switching valve 110 that controls the flow direction of the refrigerant. For example, the flow switching valve 110 may include four sides.

The air conditioner 10 is disposed on the outlet side of the compressor 100 and may further include a condenser 120 that condenses the refrigerant compressed in the compressor 100. A discharge pipe 30 is connected to the discharge port 102 of the compressor 100, and the discharge pipe 30 may be connected to the flow switching valve 110.

The condenser 120 may be configured as an air-refrigerant heat exchanger in which heat exchange is performed between the refrigerant and air. A condensation fan that blows air toward the condenser 120 may be installed on one side of the condenser 120.

The flow switching valve 110 may include a first port connected to the discharge pipe 30 of the compressor 100 and a second port connected to the inlet pipe of the condenser 120.

The flow switching valve 110 may be connected to the suction pipe 20. The flow conversion valve 110 is connected to a third port connected to the outlet pipe of the evaporator 140 among the suction pipes 20 and a pipe extending from the flow conversion valve 110 to the gas-liquid separator 150. It may further include a fourth port for connection.

The air conditioner 10 may further include a main expansion valve 161 disposed on the outlet side of the condenser 120 to depressurize the refrigerant condensed in the condenser 120. For example, the main expansion valve 161 may include an electronic expansion valve (EEV) that can control the degree of decompression of the refrigerant by adjusting the opening degree.

The main expansion valve 161 may be installed in the condensation pipe 40 connecting the condenser 120 and the evaporator 140.

The air conditioner 10 may further include a supercooler 130 provided at the inlet side of the main expansion valve 161. That is, the main expansion valve 161 may be disposed on the outlet side of the supercooler 130.

The air conditioner 10 may further include an evaporator 140 that is disposed on the outlet side of the main expansion valve 161 and evaporates the refrigerant decompressed in the main expansion valve 161. The evaporator 140 may be configured as an air-refrigerant heat exchanger in which heat exchange is performed between the refrigerant and air. An evaporation fan that blows air toward the evaporator 140 may be installed on one side of the evaporator 140.

The gas-liquid separator 150 is installed on the outlet side of the evaporator 140. The refrigerant evaporated in the evaporator 140 flows into the gas-liquid separator 150 through the flow conversion valve 110 and is separated into gas and liquid, and the separated gaseous refrigerant can be sucked into the compressor 100.

A first branch 45 located on the outlet side of the condenser 120 may be formed in the condensation pipe 40. The first branch portion 45 may be formed on the outlet side of the supercooler 130 and the inlet side of the first expansion valve 161.

The air conditioner 10 may further include a supercooling pipe 50 branched from the first branch 45 and extending to the supercooler 130. Some of the main refrigerant that has passed through the condenser 120 may be branched into the supercooling pipe 50 and flow into the subcooler 130.

The supercooling pipe 50 can be understood as a pipe for bypassing some of the main refrigerant and injecting it into the compressor 100.

The supercooler 130 can be understood as a heat exchanger in which heat is exchanged between the main refrigerant flowing through the condensation pipe 40 and the branch refrigerant flowing through the supercooling pipe 50.

Referring to FIG. 3, the supercooler 130 may include a double pipe structure. In detail, the supercooler 130 may include an outer tube 131 and an inner tube 133 provided inside the outer tube 131. The inner tube 133 may include multiple tubes.

The space formed outside the inner tube 133 as the inner space of the outer tube 131 may form a flow space 135 in which the main refrigerant of the condensation pipe 40 flows. The branch refrigerant of the supercooling pipe 50 may flow in the inner tube 133.

The supercooling pipe 50 may form the inner tube 133, and the condensation pipe 40 may form the outer tube 131.

A supercooling expansion valve 163 for depressurizing the branch refrigerant may be installed in the supercooling pipe 50. For example, the supercooled expansion valve 163 may include an electronic expansion valve (EEV) that can control the degree of decompression of the refrigerant by adjusting the opening degree.

The branch refrigerant may be decompressed in the process of passing through the supercooled expansion valve 163 and phase changed to a state of a refrigerant in which liquid refrigerant and gaseous refrigerant are mixed.

A second branch 55 may be formed in the supercooling pipe 50 at the outlet side of the supercooling expansion valve 163 and separates the liquid refrigerant and the gaseous refrigerant among the abnormal refrigerants. The supercooled expansion valve 163 may be installed in the pipe between the first branch 45 and the second branch 55.

In order to easily separate the liquid refrigerant and the gaseous refrigerant, the second branch portion 55 may be configured by a T-shaped or Y-shaped pipe.

In the pipe forming the second branch portion 55, the liquid refrigerant (Lp) may be located at the bottom of the pipe based on the direction of gravity, and the gaseous refrigerant (Gp) with a large specific volume may be located at the top of the pipe. Through this layer separation and flow, the liquid refrigerant and the gaseous refrigerant can be separated.

The gaseous refrigerant separated from the second branch 55 may be injected into the compressor 100. In detail, the air conditioner 10 may include a second injection pipe 70 extending from the second branch portion 55 to the suction side of the compressor 100.

The second injection pipe 70 may be connected to the suction pipe 20. The suction pipe 20 may include a joining portion 25 to which the second injection pipe 70 is connected.

The joining part 25 is formed on the suction side of the suction port 101 of the compressor 100, and the refrigerant flowing through the second injection pipe 70 flows from the joining part 25 to the evaporator 140. ) can be combined with the evaporated refrigerant and sucked into the suction port 101 of the compressor 100.

The liquid refrigerant separated from the second branch portion 55 may flow into the supercooler 130. Among the refrigerants decompressed in the supercooling expansion valve 163, the vapor phase refrigerant is a refrigerant that does not require additional heat exchange and is injected into the compressor 100, while the separated liquid refrigerant flows into the supercooler 130 and is discharged into the condensation pipe. It can exchange heat with the refrigerant of (40).

In the heat exchange process, the low-pressure refrigerant flowing through the supercooling pipe 50 may absorb heat from the high-pressure refrigerant (liquid refrigerant) flowing through the condensation pipe 40 and be vaporized. And, the refrigerant in the condensation pipe 40 may be supercooled.

In this way, before the refrigerant flowing through the supercooling pipe 50 flows into the supercooler 130, the gaseous refrigerant is first separated and injected into the compressor 100, and the separated liquid refrigerant is injected into the supercooler ( 130) and can exchange heat with the refrigerant in the condensation pipe 40, so heat exchange efficiency can be improved.

The refrigerant in the supercooled pipe 50 that absorbs heat and vaporizes in the supercooler 130 may be injected into the compressor 100. In detail, the first injection pipe 60 may be connected to the supercooling pipe 50 at the outlet side of the supercooler 130. For example, the supercooling pipe 50 and the first injection pipe 60 may be formed as one body.

The first injection pipe 60 may be connected to the injection port 103 of the compressor 100. The refrigerant vaporized in the supercooler 130 flows through the first injection pipe 60 and can be injected into the compressor 100 through the injection port 103.

The injection port 103 may be formed adjacent to a position where the refrigerant sucked into the compression chamber begins to be compressed. In the process of continuous suction, compression, and discharge in the compressor 100, the refrigerant injected through the injection port 103 can form approximately an intermediate pressure between the suction pressure and the discharge pressure.

In this way, since refrigerant can be injected into the compressor 100 through the first injection pipe 60 and the second injection pipe 70, the amount of injected refrigerant increases, and this increases the evaporator in the heating and low temperature area, which is an area with a large specific volume. Pressure loss in the evaporator can be improved by reducing the amount of refrigerant flowing into the evaporator.

Additionally, since the gaseous refrigerant can be injected into the compressor through the first and second injection pipes 60 and 70, liquid refrigerant can be prevented from being injected into the compressor, and thus the reliability of the compressor can be improved.

Figure 4 is a diagram showing a first example of the connection structure of the supercooling piping and the supercooling expansion valve according to the first embodiment of the present invention, and Figure 5a shows the stratified flow required for easy separation of gaseous refrigerant and liquid refrigerant. It is a graph showing flow conditions, and FIG. 5b is a schematic diagram showing stratified flow and other flows in contrast to the stratolaminar flow.

Referring to FIGS. 2 and 4 together, the supercooling pipe 50 branching from the first branch 45 of the condensation pipe 40 and extending to the supercooler 130 is located on the inlet side of the supercooling expansion valve 163. It may include a first piping part 51 connected to the outlet side of the supercooled expansion valve 163 and a second piping part 52 connected to the outlet side of the supercooled expansion valve 163.

The refrigerant whose pressure is reduced in the supercooled expansion valve 163 flows through the second piping section 52 and may have the flow characteristics of an ideal refrigerant depending on dryness and mass flow rate.

The second piping unit 52 may include a T-shaped pipe.

The second piping portion 52 may include a valve connection portion 52a connected to the outlet end of the supercooled expansion valve 163. The valve connection part 52a may include a first connection end 52a1 connected to the outlet end of the supercooled expansion valve 163.

The valve connection portion 52a may have a bent shape.

In detail, the valve connection portion 52a includes a first part extending downward from the outlet end of the supercooled expansion valve 163 corresponding to the direction of gravity, and a first part bent from the first part to be parallel to the ground G. ) may include a second part extending in the direction.

The downward direction corresponding to the direction of gravity may be a direction from the supercooled expansion valve 163 toward the ground (G).

The ground G may be understood as a surface on which the air conditioner 10 is installed. For example, the air conditioner 10 includes a base having an installation surface on which the compressor 100 is placed, and the ground G can be understood as an installation surface of the base.

The second piping portion 52 may further include a first branch pipe 52b branched from the valve connection portion 52a. The first branch pipe 52b may be branched from the second branch portion 55 of the second pipe portion 52 and connected to the supercooler 130. The end of the first branch pipe 52b may have a second connection end 52b1 connected to the supercooler 130.

The first branch pipe 52b may extend from the second branch portion 55 in a direction substantially parallel to the ground (G).

The second piping portion 52 may further include a second branch pipe 52c branched from the valve connection portion 52a. The second branch pipe 52c may be branched from the second branch portion 55 of the second pipe portion 52 and connected to the second injection pipe 70. The end of the second branch pipe 52c may have a third connection end 52c1 connected to the second injection pipe 70.

The second branch pipe 52c may be placed at a higher position than the first branch pipe 52b. For example, the second branch pipe 52c may extend upward from the second branch portion 55.

The angle formed by the second branch pipe (52c) and the first branch pipe (52b) may be approximately 90 degrees (vertical).

The second connection end 52b1 of the first branch pipe 52b is located at a first height H1 from the ground G, and the second branch pipe 52c is located above the first branch pipe 52b. The height of the third connection end 52c1 may be configured to form a second height H2.

Due to this configuration, the refrigerant is phase separated in the second branch portion 55, so that the liquid refrigerant can flow into the first branch pipe (52b) and the gaseous refrigerant can flow into the second branch pipe (52c). there is.

Referring to FIGS. 5A and 5B, it is preferable that the two-phase refrigerant forms a stratified flow to facilitate phase separation of the refrigerant in the second branch portion 55.

In the drawing, (A) shows slug flow, (B) shows annular flow, (C) shows dry out, and (D) shows the stratified flow. It shows. The laminar flow can be understood as a flow that facilitates the phase separation of the refrigerant required in the present invention.

Figure 5a shows areas of mass flow rate according to dryness, and the flows corresponding to each area (A), (B), (C), and (D) can be matched.

In order for the ideal refrigerant to form a stratified flow, the mass flow rate (refrigerant flow rate) of the refrigerant needs to be up to 250 kg/m2*s. The opening degree of the supercooled expansion valve 163 may be adjusted to form this mass flow rate.

Additionally, the diameter and length of the second piping portion 52 may act as factors affecting the flow of abnormal refrigerant.

In detail, the distance between the first part of the valve connection portion 52a and the second branch pipe 523c needs to be spaced apart by a set distance L1. For example, the set distance L1 may be determined in a range of 15 cm or more.

The set distance (L1) corresponds to the length of the second part of the valve connection (52a), and when the length of the second part extending in a direction parallel to the ground (G) is secured at a certain length or more, in the refrigerant flow process Space for phase separation can be secured.

In order to facilitate phase separation of the refrigerant, the diameter of the second piping part 52 through which the abnormal refrigerant flows by reducing the pressure in the supercooling expansion valve 163 is formed to be larger than the diameter of the first piping part 51 through which the liquid refrigerant flows. It can be.

In this way, when the pipe diameter and length of the supercooling pipe 50 and the mass flow rate of the refrigerant are within an appropriate range, a stratified flow is formed in the second pipe portion 52 to facilitate phase separation of the refrigerant. It can be done.

The gaseous refrigerant phase-separated in the second branch 55 flows upward through the second branch pipe 52c and flows to the second injection pipe 70, and the phase-separated liquid refrigerant flows through the first branch pipe 52b. It may flow into the supercooler 130 from a position lower than the second branch pipe 52c.

Figure 6 is a diagram showing a second example of the connection structure of a supercooled pipe and a supercooled expansion valve according to the first embodiment of the present invention.

Referring to FIG. 6, the second example has a difference in the direction in which the second branch pipe 52c' extends compared to FIG. 4. The other components, the first piping part 51', the valve connection part 52a', and the first branch pipe 52b', are the first piping part 51, the valve connection part 52a, and the first branch pipe 52b' described in FIG. The explanation of the branch pipe 52b is used.

The second piping unit 52' according to the second example may include a Y-shaped pipe.

Based on the ground (G), the second branch pipe (52c') may be placed at a higher position than the first branch pipe (52b'). The angle θ formed by the second branch pipe 52c' and the first branch pipe 52b' may form an acute angle (an angle greater than 0 degrees and less than 90 degrees).

According to this structure, the gaseous refrigerant separated in the second branch portion 55 flows upward along the second branch pipe 52c', and the separated liquid refrigerant flows toward the supercooler 130 on the ground (G). It may extend in a direction approximately parallel to .

According to this configuration, phase separation of the refrigerant can be easily achieved.

Figure 7 is a refrigeration cycle diagram showing the configuration of an air conditioner according to a second embodiment of the present invention.

Referring to Figure 7, the air conditioner (10a) according to the second embodiment of the present invention differs from the first embodiment only in the configuration of the first injection pipe (60a) and the second injection pipe (70a), so the difference is The explanation will be mainly given, and for other parts that are the same, the description of the first embodiment (FIG. 1) will be used.

The air conditioner 10a is connected to the supercooling pipe 50 at the outlet side of the supercooler 130 and may include a first injection pipe 60a connected to the joint portion 25 of the compressor 100. .

The air conditioner 10a is connected to the second branch portion 55 and may include a second injection pipe 70a connected to the injection port 103 of the compressor 100.

When considering the first and second embodiments of the present invention together, for convenience of explanation, the port of the compressor 100 through which the refrigerant flowing through the first injection pipe 60a is injected is referred to as the “first port.” , the port of the compressor 100 through which the refrigerant flowing through the second injection pipe 70a is injected may be called “second port.”

According to this configuration, the phase-separated or heat-exchanged gaseous refrigerant can be easily injected into the compressor 100 through the first and second injection pipes 60a and 70a.

Figure 8 is a refrigeration cycle diagram showing the configuration of an air conditioner according to a third embodiment of the present invention.

Referring to FIG. 8, the air conditioner 10b according to the third embodiment of the present invention is similar to the first embodiment only in that valves for controlling the refrigerant flow rate are provided in the first and second injection pipes 60 and 70. Since there is a difference, the explanation will focus on the differences, and the description of the first embodiment (FIG. 1) will be used for other parts that are the same.

A first control valve 181 may be installed in the first injection pipe 60 to control the amount of refrigerant flowing through the first injection pipe 60.

A second control valve 183 may be installed in the second injection pipe 70 to control the amount of refrigerant flowing through the second injection pipe 70.

The first and second control valves 181 and 183 may be configured as either a solenoid valve capable of on-off control or an electronic expansion valve capable of adjusting the opening degree.

Since the amount of refrigerant injected through the first and second injection pipes (60, 70) can be adjusted through control of the first and second control valves (181 and 183), the cycle formation range during operation of the air conditioner (10) can be adjusted. Accordingly, the amount of refrigerant bypassed by the compressor can be easily adjusted.

10: air conditioner 20: suction pipe
25: joint part 30: discharge pipe
40: condensation pipe 45: first branch
50: Supercooling pipe 51: First pipe section
52: second piping section 55: second branch section
100: Compressor 110: Flow conversion valve
120: condenser 130: supercooler
140: Evaporator 150: Gas-liquid separator
161: first expansion valve 163: second expansion valve

Claims (13)

A compressor including first and second ports and a condenser for condensing the refrigerant compressed in the compressor;
a main expansion valve provided on the outlet side of the condenser;
an evaporator that evaporates the refrigerant reduced in pressure from the main expansion valve;
a condensation pipe connecting the condenser and the evaporator and forming a first branch;
a supercooling pipe branched from the first branch;
a subcooler that performs heat exchange between the main refrigerant flowing in the condensation pipe and the branch refrigerant flowing in the supercooling pipe;
a supercooling expansion valve installed in the supercooling pipe and disposed on an inlet side of the supercooler;
a second branch formed on the outlet side of the supercooled expansion valve;
a first injection pipe connected to the supercooling pipe at an outlet side of the subcooler and injecting the refrigerant heat exchanged in the supercooler into a first port of the compressor; and
A second injection pipe branched from the second branch and through which gaseous refrigerant among the refrigerant decompressed in the supercooled expansion valve flows and is injected into the second port of the compressor,
An air conditioner that performs refrigerant injection into the compressor. According to paragraph 1,
The second branch is formed at the inlet side of the supercooler,
The supercooled expansion valve is installed at a point between the first branch and the second branch so that the refrigerant decompressed in the supercooled expansion valve can flow from the second branch to the second injection pipe.
An air conditioner that performs refrigerant injection into the compressor. According to paragraph 1,
The supercooling pipe is configured to achieve phase separation of the refrigerant into a gaseous refrigerant to be flowed from the second branch to the second injection pipe and a liquid refrigerant to be flowed into the supercooler.
Including a first branch pipe and a second branch pipe,
An air conditioner that performs refrigerant injection into the compressor. According to paragraph 3,
So that the gaseous refrigerant flows to the second injection pipe through the second branch pipe and the liquid refrigerant flows to the supercooler through the first branch pipe,
The second branch pipe is disposed at a higher position than the first branch pipe relative to the ground,
An air conditioner that performs refrigerant injection into the compressor. According to clause 4,
Based on the ground, the height (H2) of the connection end where the second branch pipe is connected to the second injection pipe is greater than the height (H1) of the connection end where the first branch pipe is connected to the supercooler. ,
An air conditioner that performs refrigerant injection into the compressor. According to paragraph 3,
The second branch pipe extends upward from the first branch pipe in the direction opposite to the ground in the second branch portion,
An air conditioner that performs refrigerant injection into the compressor. According to clause 6,
The supercooling pipe includes a T-shaped pipe so that the second branch pipe is perpendicular to the first branch pipe,
An air conditioner that performs refrigerant injection into the compressor. According to clause 6,
The supercooling pipe includes a Y-shaped pipe so that the angle formed by the second branch pipe with respect to the first branch pipe forms an acute angle.
An air conditioner that performs refrigerant injection into the compressor. According to paragraph 3,
The supercooling piping includes a first piping portion connected to an inlet side of the supercooling expansion valve and a second piping portion connected to an outlet side of the supercooling expansion valve,
The second piping portion includes a first part extending downward toward the ground and a second part extending by bending from the first part,
An air conditioner that performs refrigerant injection into the compressor. According to clause 9,
The second part extends parallel to the ground so that the first part and the second branch pipe can be separated by a set distance,
An air conditioner that performs refrigerant injection into the compressor. According to paragraph 1,
In order to form a stratified flow of refrigerant in the second branch, the opening degree of the supercooled expansion valve is adjusted in a range where the mass flow rate of the refrigerant flowing through the supercooled pipe is up to 250 kg/m2*s,
An air conditioner that performs refrigerant injection into the compressor. According to paragraph 1,
The first port is one of the suction port and injection port of the compressor, and the second port is the other one of the suction port and injection port of the compressor,
An air conditioner that performs refrigerant injection into the compressor. According to paragraph 1,
At least one of the first and second injection pipes is provided with a control valve for controlling the amount of injected refrigerant,
An air conditioner that performs refrigerant injection into the compressor.

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