AIR CONDITIONER

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the priority benefit of Korean Patent Application No. 10-2025-0003212, filed on January 09, 2025, the disclosures of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the invention

[0002] The present disclosure relates to an air conditioner, and more specifically, an air conditioner that allows phase separation of a refrigerant.

Description of the Related Art

[0003] An air conditioner is a device that can be used in various environments such as industrial, commercial, or residential buildings, and it can cool or heat a desired space or equipment through a heat exchange process using a refrigerant.

[0004] Today, various eco-friendly alternative refrigerants are developed and used to reduce the global warming potential (GWP) of refrigerants.

[0005] However, these alternative refrigerants are often accompanied by temperature glide during condensation and evaporation processes. Therefore, in the phase change process of a refrigerant, the temperature is not constant, so there is a problem in that heat exchange efficiency decreases and the efficiency of an air conditioner is reduced.

[0006] This problem is a major cause of hindering the use of alternative refrigerants, and the inability to use alternative refrigerants may accelerate global warming.

SUMMARY OF THE INVENTION

[0007] An objective of the present disclosure is to provide an air conditioner capable of solving the various problems of the related art described above.

[0008] Another objective of the present disclosure is to provide an air conditioner capable of separating a liquid refrigerant at an intermediate section of a condenser.

[0009] Another objective of the present disclosure is to provide an air conditioner capable of improving the separation ratio of a vapor refrigerant and a liquid refrigerant at an intermediate section of a condenser.

[0010] Another objective of the present disclosure is to provide an air conditioner capable of increasing the subcooling degree of a liquid refrigerant separated at an intermediate section of a condenser.

[0011] Another objective of the present disclosure is to provide an air conditioner of which the heat exchange efficiency is improved even though it uses a substitute refrigerant that exhibits temperature glide.

[0012] The objectives of the present disclosure are not limited to those described above and other objectives not stated above may be made apparent to those skilled in the art from the following description.

[0013] In order to achieve the objectives, an air conditioner according to an embodiment of the present disclosure includes: a compressor configured to compress a refrigerant; a condenser having a heat exchange pipe into which the refrigerant discharged from the compressor is introduced; an evaporator configured to evaporate the refrigerant from the condenser; and a vapor-liquid separator configured to separate a portion of the refrigerant flowing through the heat exchange pipe, wherein the heat exchange pipe includes a first pipe into which the refrigerant discharged from the compressor is introduced, and a second pipe connected between the first pipe and the evaporator, and wherein the vapor-liquid separator includes a vapor-liquid separating pipe configured to separate a vapor refrigerant from the first pipe and direct the vapor refrigerant to the second pipe, and a bypass pipe through which a liquid refrigerant separated from the first pipe flows.

[0014] The condenser may further include a subcooling pipe configured to cool the liquid refrigerant from the bypass pipe.

[0015] The vapor-liquid separating pipe may include an insertion pipe inserted in the first pipe, and the insertion pipe may include a tapered portion of which at least a portion is spaced apart from an inner surface of the first pipe, and an extending portion extending from an end of the tapered portion.

[0016] The refrigerant may be a zeotropic mixture.

[0017] Lengths of the first pipe and the second pipe may be set in consideration of quality of the refrigerant flowing through the heat exchange pipe.

[0018] According to the air conditioner of the present disclosure, one or more effects can be achieved as follows.

[0019] It is possible to separate a liquid refrigerant at an intermediate section of the condenser through the vapor-liquid separator, and improve heat exchange efficiency.

[0020] It is possible to improve the separation ratio of a vapor refrigerant and a liquid refrigerant at an intermediate section of the condenser due to the structure of the tapered portion and the extending portion of the vapor-liquid separating pipe.

[0021] It is possible to increase the subcooling degree of a liquid refrigerant separated at the intermediate section of the condenser due to the subcooling pipe through which a liquid refrigerant flows.

[0022] It is possible to improve heat exchange efficiency by separating a liquid refrigerant having a lower temperature than a vapor refrigerant when a zeotropic mixture condenses.

[0023] The effects of the present disclosure are not limited to those described above and other effects not stated herein may be made apparent to those skilled in the art from claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024]FIG. 1 schematically illustrates an air conditioner according to an embodiment of the present disclosure.

[0025]FIG. 2 illustrates a condenser according to an embodiment of the present disclosure and an enlarged view thereof.

[0026]FIG. 3 illustrates a vapor-liquid separator according to an embodiment of the present disclosure.

[0027]FIG. 4 illustrates the flow of a refrigerant during a cooling operation of the air conditioner according to an embodiment of the present disclosure.

[0028]FIG. 5 illustrates the flow of a refrigerant during a heating operation of the air conditioner according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

[0029] Hereafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings and the same or similar components are given the same reference numerals regardless of the numbers of figures and are not repeatedly described.

[0030] Terms “module” and “unit” that are used for components in the following description are used only for the convenience of description without having discriminate meanings or functions.

[0031] In the following description, if it is decided that the detailed description of known technologies related to the present disclosure makes the subject matter of the embodiments described herein unclear, the detailed description is omitted. Further, the accompanying drawings are provided only for easy understanding of embodiments disclosed in the specification, the technical spirit disclosed in the specification is not limited by the accompanying drawings, and all changes, equivalents, and replacements should be understood as being included in the spirit and scope of the present disclosure.

[0032] Terms including ordinal numbers such as “first” and “second” may be used to describe various components, but the components are not to be construed as being limited to the terms. The terms are used only to distinguish one component from another component.

[0033] It should be understood that when one component is referred to as being “connected to” or “coupled to” another component, it may be connected directly to or coupled directly to another component or be connected to or coupled to another component with the other component therebetween. On the other hand, it should be understood that when one component is referred to as being “connected directly to” or “coupled directly to” another component, it may be connected to or coupled to another component without other components therebetween.

[0034] Singular forms are intended to include plural forms unless the context clearly indicates otherwise.

[0035] It will be further understood that the terms "comprises" or "have" used in this specification, specify the presence of stated features, steps, operations, components, parts, or a combination thereof, but do not preclude the presence or addition of one or more other features, numerals, steps, operations, components, parts, or a combination thereof.

[0036] Referring to FIG. 1, the configuration of an air conditioner 1 according to an embodiment of the present disclosure can be seen.

[0037]The compressor 11 compresses a refrigerant. The compressor 11 can compress a vapor refrigerant and then discharge it. A flow of the refrigerant can be generated by a pressure difference produced by the compressor 11. The compressed refrigerant may be in a superheated vapor state of high temperature and high pressure.

[0038] A switching valve 12 can switch a flow path. The switching valve 12 may be connected to the compressor 11 and a discharge flow path 61. The switching valve 12 can direct the refrigerant discharged from the compressor 11 to an outdoor heat exchanger 20 or an indoor heat exchanger 14 to be described below. The switching valve 12 may be a four-way valve.

[0039] When the refrigerant discharged from the compressor 11 is directed to the outdoor heat exchanger 20 through the switching valve 12, the outdoor heat exchanger 20 can function as a condenser. In this case, the air conditioner 1 can operate in a cooling mode.

[0040] When the refrigerant discharged from the compressor 11 is directed to the indoor heat exchanger 14 through the switching valve 12, the indoor heat exchanger 14 can function as a condenser. In this case, the air conditioner 1 can operate in a heating mode.

[0041] The outdoor heat exchanger 20 can exchange heat between a refrigerant and air. A refrigerant can pass through the outdoor heat exchanger 20. A refrigerant can exchange heat with air while passing through the outdoor heat exchanger 20. The outdoor heat exchanger 20 and the switching valve 12 may be connected through a first connecting flow path 62.

[0042] The indoor heat exchanger 14 can exchange heat between a refrigerant and a predetermined heat medium. A refrigerant can pass through the indoor heat exchanger 14. A refrigerant can exchange heat with a heat medium while passing through the indoor heat exchanger 14. For example, the heat medium may be water. The indoor heat exchanger 14 and the switching valve 12 may be connected through a second connecting flow path 64.

[0043] An intermediate flow path 63 can connect the outdoor heat exchanger 20 and the indoor heat exchanger 14. The intermediate flow path 63 may include a first intermediate flow path 63a, a second intermediate flow path 63b, and a third intermediate flow path 63c.

[0044] A first expansion valve 71 and a second expansion valve 72 may be disposed in the intermediate flow path 63. The first expansion valve 71 and the second expansion valve 72 may be electric expansion valves (EEVs). The openings of the first expansion valve 71 and the second expansion valve 72 is controlled, whereby the expansion of a refrigerant can be regulated.

[0045]Alternatively, the first expansion valve 71 and the second expansion valve 72 may be fully opened or closed.

[0046] The first intermediate flow path 63a may refer to the portion of the intermediate flow path 63 that connects the outdoor heat exchanger 20 and the first expansion valve 71.

[0047] The second intermediate flow path 63b may refer to the portion of the intermediate flow path 63 that connects the first expansion valve 71 and the second expansion valve 72.

[0048] The third intermediate flow path 63c may refer to the portion of the intermediate flow path 63 that connects the second expansion valve 72 and the indoor heat exchanger 14.

[0049] A subcooler 13 can cool a refrigerant. The subcooler 13 can improve the efficiency of the air conditioner 1 by cooling a refrigerant below a saturation temperature. A second inlet flow path 66 can connect the second intermediate flow path 63b and the compressor 11. The subcooler 13 may be disposed between the second intermediate flow path 63b and the second inlet flow path 66.

[0050]The third expansion valve 73 may be disposed between the point at which the second intermediate flow path 63b is connected to the second inlet flow path 66 and the subcooler 13. The third expansion valve 73 can expand a portion of a refrigerant introduced from the second intermediate flow path 63b and direct it to the subcooler 13. The subcooler 13 can cool the refrigerant flowing through the second intermediate flow path 63b below a saturation temperature by exchanging heat between the expanded low-temperature refrigerant and the remaining refrigerant.

[0051]The switching valve 12 and the compressor 11 may be connected through a first inlet flow path 65. An accumulator 15 may be disposed on the first inlet flow path 65.

[0052]The accumulator 15 can provide a vapor refrigerant to the compressor 11. The accumulator 15 can separate a vapor refrigerant and a liquid refrigerant. The accumulator 15 can prevent a liquid refrigerant from being introduced into the compressor 11.

[0053] The air conditioner 1 may include a plurality of sensors (not shown) that measure a temperature or a pressure of a refrigerant flowing through a refrigerant pipe.

[0054] A controller C (not shown) can control the operation of the air conditioner 1. The controller C may be electrically connected to each of the components of the air conditioner 1 described above. The controller C can control the operation of the components of the air conditioner 1, whereby the air conditioner 1 can operate in a heating mode or a cooling mode.

[0055]The outdoor heat exchanger 20 may include a heat exchange pipe 21, a subcooling pipe 24, a vapor-liquid separator 30, a first valve 28, etc.

[0056] When the outdoor heat exchanger 20 functions as a condenser, the refrigerant discharged from the compressor 11 can condense by exchanging heat with air while passing through the heat exchange pipe 21.

[0057]The vapor-liquid separator 30 can separate a refrigerant flowing through the heat exchange pipe 21 into a liquid refrigerant and a vapor refrigerant. The liquid refrigerant separated through the vapor-liquid separator 30 can flow to the subcooling pipe 24. The liquid refrigerant and the vapor refrigerant referred to below include not only a case in which they are completely in a liquid state or in a vapor state but also a case in which they are mostly in a liquid state or mostly in a vapor state.

[0058] The subcooling pipe 24 can cool the separated liquid refrigerant below a saturation temperature. Accordingly, damage to the expansion valve is prevented, whereby the stability of the air conditioner 1 can be improved. Further, more heat is absorbed in the evaporator, whereby the performance of the air conditioner 1 can be improved. The subcooling pipe 24 can be separated from the heat exchange pipe 21 as a separate region.

[0059]The first valve 28 may be disposed in the vapor-liquid separator 30. The flow of a refrigerant can be adjusted according to the opening and closing of the first valve 28. For example, when the outdoor heat exchanger 20 functions as a condenser, the first valve 28 can be opened, whereby a liquid refrigerant can be separated and can flow from the heat exchange pipe 21 to the subcooling pipe 24. By way of another example, when the indoor heat exchanger 14 functions as a condenser, the first valve 28 can be closed, and a refrigerant can flow only to the heat exchange pipe 21 without flowing to the subcooling pipe 24.

[0060] The first valve 28 may be a check valve 28 that allows a refrigerant to flow from the heat exchange pipe 21 to the subcooling pipe 24. Accordingly, when the outdoor heat exchanger 20 functions as a condenser, a refrigerant flows from the heat exchange pipe 21 to the subcooling pipe 24, but when the indoor heat exchanger 14 functions as a condenser, a refrigerant may not flow from the subcooling pipe 24 to the heat exchange pipe 21. When the first valve 28 is a check valve 28, the flow of a refrigerant can be controlled even without involvement of the controller C, whereby the complexity of the system of the air conditioner 1 can be reduced and control stability can be improved.

[0061] Meanwhile, since when the refrigerant discharged from the compressor 11 is directed to the indoor heat exchanger 14 through the switching valve 12, the indoor heat exchanger 14 can function as a condenser, the indoor heat exchanger 14, unlike this figure, may include the heat exchange pipe 21, the subcooling pipe 24, the vapor-liquid separator 30, the first valve 28, etc.

Cooling Operation Mode of Air Conditioner

[0062] Referring to the solid line shown for the switching valve 12 in FIG. 1, when a cooling operation signal is received by the air conditioner 1, the controller C can perform a cooling operation of the air conditioner 1. For example, the cooling operation signal may be a signal that is arbitrarily input by a user. By way of another example, the cooling operation signal may be a signal that a thermostat installed in an indoor space provides to the controller C when an indoor temperature detected by an indoor temperature sensor is higher than a desired temperature set by a user by a predetermined level or more.

[0063] During the cooling operation, the refrigerant discharged from the compressor 11 can be directed to the outdoor heat exchanger 20 by the switching valve 12. In this case, the outdoor heat exchanger 20 can function as a condenser and the indoor heat exchanger 14 can function as an evaporator.

[0064]A liquid refrigerant of the refrigerant passing through the outdoor heat exchanger 20 can flow to the subcooling pipe 24 through the vapor-liquid separator 30. The refrigerant passing through the subcooling pipe 24 can be cooled below a saturation temperature while exchanging heat with air.

[0065] A vapor refrigerant separated through the vapor-liquid separator 30 can condense into a liquid refrigerant by exchanging heat with air while passing through the heat exchange pipe 21.

[0066] The refrigerant that has passed through the heat exchange pipe 21 and the refrigerant that has passed through the subcooling pipe 24 can be merged in the first intermediate flow path 63a.

[0067] The first expansion valve 71 can be fully opened so that it does not expand the refrigerant passing through it. The refrigerant can be cooled below a saturation temperature while passing through the subcooler 13, and can expand while passing through the second expansion valve 72.

[0068] The expanded refrigerant can evaporate by exchanging heat with a heat medium while passing through the indoor heat exchanger 14. The evaporated refrigerant is directed to the accumulator 15 through the switching valve 12, and the vapor refrigerant in the accumulator 15 is directed to the compressor 11, so it can continuously circulate.

Heating Operation Mode of Air Conditioner

[0069] Referring to the dotted line shown for the switching valve 12 in FIG. 1, when a heating operation signal is received by the air conditioner 1, the controller C can perform a heating operation of the air conditioner 1. For example, the heating operation signal may be a signal that is arbitrarily input by a user. By way of another example, the heating operation signal may be a signal that a thermostat installed in an indoor space provides to the controller C when an indoor temperature detected by an indoor temperature sensor is lower than a desired temperature set by a user by a predetermined level or more.

[0070] During the heating operation, the refrigerant discharged from the compressor 11 can be directed to the indoor heat exchanger 14 by the switching valve 12. In this case, the indoor heat exchanger 14 can function as a condenser and the outdoor heat exchanger 20 can function as an evaporator.

[0071] While passing through the indoor heat exchanger 14, the refrigerant can exchange heat with a heat medium and can condense into a liquid refrigerant.

[0072] The second expansion valve 72 can be fully opened so that the refrigerant passing through it does not expand. The refrigerant can be cooled below a saturation temperature while passing through the subcooler 13, and can expand while passing through the first expansion valve 71.

[0073] The expanded refrigerant can flow to the heat exchange pipe 21. In this case, due to the closure of the first valve 28 or the directionality of the check valve 28, the refrigerant may not flow from the first intermediate flow path 63a to the subcooling pipe 24.

[0074] The refrigerant can evaporate while flowing through the heat exchange pipe 21. The evaporated refrigerant is directed to the accumulator 15 through the switching valve 12, and the vapor refrigerant in the accumulator 15 is directed to the compressor 11, so it can continuously circulate.

[0075] Referring to FIG. 2, a configuration of the outdoor heat exchanger 20 can be seen.

[0076] The outdoor heat exchanger 20 may include a plurality of passes. The outdoor heat exchanger 20 may have a plurality of heat exchange pipes 21a and 21b. Only the first heat exchange pipe 21a and the second heat exchange pipe 21b are illustrated in this figure, but the outdoor heat exchanger 20 may have one pipe or three or more pipes.

[0077]The outdoor heat exchanger 20 may include a header 25. The header 25 can distribute the refrigerant discharged from the compressor 11 to a plurality of passes or can merge the refrigerant introduced from the plurality of passes. The header 25 may be connected to the heat exchange pipes 21a and 21b. The header 25 may be connected to one end of a plurality of first pipes 22.

[0078]The heat exchange pipe 21a and 21b each may include a first pipe 22 and a second pipe 23. The first pipe 22 and the second pipe 23 can be separated by the vapor-liquid separator 30, which will be described later. When the outdoor heat exchanger 20 functions as a condenser, the refrigerant discharged from the compressor 11 can be introduced into the first pipe 22. The second pipe 23 may be connected between the first pipe 22 and the indoor heat exchanger 14.

[0079]The first pipe 22 and the second pipe 23 may be connected to a vapor-liquid separator 30. The vapor-liquid separator 30 may include a vapor-liquid separating pipe 40 and a bypass pipe 50. The vapor-liquid separating pipe 40 can separate a vapor refrigerant from the first pipe 22 and can direct it to the second pipe 23. The bypass pipe 50 can direct a liquid refrigerant separated from the first pipe 22 to the subcooling pipe 24.

[0080] One end of the first pipe 22 may be connected to the header 25 and the other end thereof may be connected to one end of the vapor-liquid separating pipe 40. One end of the second pipe 23 may be connected to the other end of the vapor-liquid separating pipe 40 and the other end thereof may be connected to a distributor 29.

[0081] The distributor 29 may be disposed on the intermediate flow path 63. When the outdoor heat exchanger 20 functions as a condenser, the distributor 29 can merge the refrigerant that has passed through the second pipe 23 and can direct it to the intermediate flow path 63. When the indoor heat exchanger 14 functions as a condenser, the distributor 29 can distribute the refrigerant flowing through the intermediate flow path 63 to a plurality of passes.

[0082]The vapor-liquid separator 30 may be provided in a number corresponding to the number of passes of the heat exchange pipes 21a and 21b. For example, as illustrated in this figure,

[0083]the heat exchange pipes 21a and 21b may be configured with two passes, and two vapor-liquid separators 30 may also be provided to be able to be connected respectively to the two passes.

[0084]The outdoor heat exchanger 20 may include an inlet header 26. The refrigerants that have passed through the bypass pipe 50 by the plurality of passes can be merged in the inlet header 26. The inlet header 26 and the subcooling pipe 24 may be connected through an inlet pipe 27.

[0085] Unlike FIG. 1, the first valve 28 or the check valve 28 may be disposed in the inlet pipe 27. Due to the first valve 28 or the check valve 28, a refrigerant may not be introduced into the inlet header 26 from the subcooling pipe 24. Meanwhile, unlike this figure, when the heat exchange pipe 21 is configured with a single pass, the first valve 28 or the check valve 28 may be disposed in the bypass pipe 50.

[0086] One end of the subcooling pipe 24 may be connected to the inlet pipe 27 and the other end thereof may be connected to the intermediate flow path 63. Accordingly, the liquid refrigerant separated by the vapor-liquid separator 30 is cooled while passing through the subcooling pipe 24, and can be merged with the refrigerant that has passed through the heat exchange pipe 21 in the intermediate flow path 63.

[0087] The heat exchange pipe 21 may be formed to be longer than the subcooling pipe 24. This can be a suitable structure for sufficiently condensing a refrigerant through the heat exchange pipe 21 and additionally cooling the liquid refrigerant separated through the subcooling pipe 24 in the outdoor heat exchanger 20 having a limited volume.

[0088]Meanwhile, in this figure, one vapor-liquid separator 30 is connected to each pass, but, unlike this figure, multiple vapor-liquid separators 30 may be connected in series to a single pass. When the vapor-liquid separators 30 are connected in series, each vapor-liquid separator 30 can separate the liquid refrigerant condensed while flowing through the heat exchange pipe 21 and divert it to the subcooling pipe 24.

[0089]For example, the vapor-liquid separator 30 may be connected in two stages. In this case, the heat exchange pipe 21 may be divided into a first pipe 22, a second pipe 23, and a third pipe as the vapor-liquid separator 30 is connected in two stages. A liquid refrigerant can be separated between the first pipe 22 and the second pipe 23 by one of the vapor-liquid separators 30, and a liquid refrigerant can be separated between the second pipe 23 and the third pipe by the other vapor-liquid separator 30.

[0090]Referring to FIG. 3, the structure of the vapor-liquid separator 30 can be seen. The flow direction of a refrigerant illustrated in this figure corresponds to the case in which the outdoor heat exchanger 20 functions as a condenser.

[0091] The refrigerant discharged from the compressor 11 can condense by exchanging heat with air while flowing through the heat exchange pipe 21. Since a refrigerant gradually condenses while flowing through the heat exchange pipe 21, the refrigerant flowing through the heat exchange pipe 21 may be a two-phase refrigerant in which a liquid refrigerant and a vapor refrigerant coexist.

[0092] Meanwhile, the flow characteristics of a two-phase refrigerant in a pipe may vary depending on a flow velocity or quality of the refrigerant. When the two-phase refrigerant flowing through the heat exchange pipe 21 has a flow velocity and quality within a predetermined range, the two-phase refrigerant can exhibit an annular flow characteristic in the heat exchange pipe 21. Here, the annular flow refers to a flow in which the flow of a vapor refrigerant having a relatively high flow velocity is concentrated in the central region of a pipe, whereas the flow of a liquid refrigerant having relatively low flow velocity and high viscosity is concentrated on an inner wall of the pipe. An annular flow characteristic may appear when the quality of a refrigerant is 0.4 to 0.6.

[0093] The vapor-liquid separating pipe 40 may include an insertion pipe 41 that is inserted in the first pipe 22. The insertion pipe 41 may include a tapered portion 42 of which at least a portion is spaced apart from the inner surface of the first pipe 22, and an extending portion 43 that extends from an end of the tapered portion 42.

[0094] The tapered portion 42 may be formed to decrease in diameter as it is inserted deeper into the first pipe 22. Accordingly, a liquid refrigerant and a vapor refrigerant flowing through the first pipe 22 can be separated. Specifically, when a refrigerant exhibits an annular flow characteristic, a vapor refrigerant is concentrated in the central region of the first pipe 22, so it can flow to the second pipe 23 through the tapered portion 42. A liquid refrigerant is concentrated on the inner wall of the first pipe 22, so it cannot pass through the tapered portion 42 and can be separated from the vapor refrigerant.

[0095] The extending portion 43 can guide a vapor refrigerant to the second pipe 23. Since the extending portion 43 extends from an end of the tapered portion 42, a liquid refrigerant and a vapor refrigerant can be separated at the extending portion 43.

[0096] The extending portion 43 may be formed to be longer than the tapered portion 42. Accordingly, even when a liquid refrigerant separated from a vapor refrigerant forms a vortex inside the pipe, the inflow of the liquid refrigerant into the separating pipe 40 can be minimized.

[0097] The bypass pipe 50 may be connected adjacent to the other end of the first pipe 22. The bypass pipe 50 can divert a liquid refrigerant separated by the insertion pipe 41.

[0098] The bypass pipe 50 may be connected to one side of the section of the first pipe 22 that surrounds the extending portion 43 and the tapered portion 42. Accordingly, backflow of a liquid refrigerant separated in the insertion pipe 41 can be prevented, vortex formation can be minimized, and the refrigerant can be effectively diverted.

[0099] The bypass pipe 50 may be connected in a direction crossing the longitudinal direction of the first pipe 22. This can be a structure that facilitates connecting the bypass pipe 50 to the first pipe 22. Further, by changing the flow direction of the liquid refrigerant separated through the insertion pipe 41, a separation ratio from a vapor refrigerant can be increased.

[0100] The separated vapor refrigerant can exchange heat with air and condense into a liquid refrigerant while flowing through the second pipe 23.

[0101] The structure of the separating pipe 30 that separates a vapor refrigerant and a liquid refrigerant can improve a heat exchange efficiency of the condenser. As a liquid refrigerant is separated, a ratio at which a vapor refrigerant exchanges heat with air can be increased. Accordingly, most of the refrigerant passing through the condenser condenses into a liquid phase, whereby the performance and efficiency of the air conditioner 1 can be improved.

[0102] Meanwhile, in order to increase a vapor-liquid separation ratio, the outdoor heat exchanger 20 or the heat exchange pipe 21 may be designed so that a two-phase refrigerant passing through the heat exchange pipe 21 exhibits an annular flow characteristic, or the operating frequency of the compressor 11 may be adjusted.

[0103] For example, the length of the first pipe 22 (see FIG. 2) may be equal to or smaller than the length of the second pipe 23 (see FIG. 2). Accordingly, a refrigerant may condense to exhibit an annular flow characteristic between the first pipe 22 and the second pipe 23, and heat exchange efficiency can be improved by separating a liquid refrigerant at the front end of the heat exchange pipe 21.

[0104]By way of another example, the lengths of the first pipe 22 and the second pipe 23 may be set in consideration of the quality of the refrigerant flowing through the heat exchange pipe 21. The lengths of the first pipe 22 and the second pipe 23 may be set so that the quality of a refrigerant becomes 0.4 to 0.6 between the first pipe 22 and the second pipe 23, whereby the vapor-liquid separation ratio can be increased.

[0105] Meanwhile, the refrigerant may be a zeotropic mixture. The zeotropic mixture may refer to a refrigerant having temperature glide during a phase-change process. The zeotropic mixture may be an eco-friendly mixed refrigerant having a low global warming potential. For example, the temperature of a refrigerant may decrease while the refrigerant condenses from a vapor phase to a liquid phase. Accordingly, the temperature of the refrigerant may gradually decrease during a process in which the refrigerant condenses while exchanging heat with air, and the temperature difference from the air may decrease. Such a decrease in the temperature difference may reduce the amount of heat exchanged between the refrigerant and the air, and the refrigerant passing through the condenser may fail to completely condense. Therefore, stability and efficiency of the air conditioner 1 may be degraded.

[0106]However, when a liquid refrigerant having a low temperature is separated through the vapor-liquid separator 30, a vapor refrigerant having a high temperature can increase the heat exchange efficiency by exchanging heat with air. As a result, the performance of the air conditioner 1 can be significantly improved.

[0107] Referring to FIG. 4, the flow of a refrigerant in the outdoor heat exchanger 20 when the air conditioner 1 operates in the cooling mode can be seen. In this case, the outdoor heat exchanger 20 can function as a condenser.

[0108]The vapor refrigerant discharged from the compressor 11 can be introduced into the header 25 through the first connecting flow path 62. In the header 25, the refrigerant can be distributed to the heat exchange pipes 21a and 21b. For example, when the heat exchange pipe 21 has two passes, as illustrated in the figure, the header 25 can distribute the refrigerant to the first heat exchange pipe 21a and the second heat exchange pipe 21b.

[0109]The vapor-liquid separating pipe 40 connecting the first pipe 22 (see FIG. 2) and the second pipe 23 (see FIG. 2) can separate a liquid refrigerant and a vapor refrigerant. The vapor-liquid separating pipe 40 can direct the vapor refrigerant to the second pipe 23. The bypass pipe 50 can divert the liquid refrigerant to the inlet header 26.

[0110] The vapor refrigerant can condense while flowing through the second pipe 23. The condensed refrigerant can be merged through the distributor 29 and can be directed to the intermediate flow path 63.

[0111] The liquid refrigerant merged in the inlet header 26 can flow to the subcooling pipe 24 through the inlet pipe 27 and the check valve 28. The liquid refrigerant can be cooled below a saturation temperature by exchanging heat with air while passing through the subcooling pipe 24. The refrigerant that has passed through the subcooling pipe 24 can be merged with the refrigerant that has passed through the second pipe 23 in the intermediate flow path 63.

[0112] Referring to FIG. 5, the flow of a refrigerant in the outdoor heat exchanger 20 when the air conditioner 1 operates in the heating mode can be seen. In this case, the outdoor heat exchanger 20 can function as an evaporator.

[0113] The refrigerant that is introduced into the outdoor heat exchanger 20 through the intermediate flow path 63 may be a two-phase refrigerant in which a liquid phase and a vapor phase are mixed.

[0114] The refrigerant may not flow to the subcooling pipe 24 by the first valve 28 or the check valve 28. The refrigerant can be distributed to the heat exchange pipes 21a and 21b by the distributor 29. For example, when the heat exchange pipes 21a and 21b have two passes, as illustrated in the figure, the distributor 29 can distribute the refrigerant to the first heat exchange pipe 21a and the second heat exchange pipe 21b.

[0115] The refrigerant can be introduced through the other end of the second pipe 23 and can flow to one end of the first pipe 22. In this case, the refrigerant may not be separated into phases while passing through the vapor-liquid separating pipe 40. Meanwhile, since the pressure of the bypass pipe 50 located at the downstream side is lower than the pressure of the subcooling pipe 24 located at the upstream side, the check valve 28 is closed, whereby the refrigerant may not flow from the bypass pipe 50 to the subcooling pipe 24.

[0116] The refrigerant that has flowed to one end of the first pipe 22 can be merged in the header 25 and can flow to the first connecting flow path 62.

[0117]Referring to FIGS. 1 to 5, an air conditioner according to an aspect of the present disclosure includes: a compressor 11 that compresses a refrigerant; a condenser 20 that has a heat exchange pipe 21 into which the refrigerant discharged from the compressor 11 is introduced; an evaporator 14 that evaporates the refrigerant from the condenser 20; and a vapor-liquid separator 30 that separates a portion of the refrigerant flowing through the heat exchange pipe 21, wherein the heat exchange pipe 21 includes a first pipe 22 into which the refrigerant discharged from the compressor 11 is introduced, and a second pipe 23 that is connected between the first pipe 22 and the evaporator 14, and wherein the vapor-liquid separator 30 includes a vapor-liquid separating pipe 40 that separates a vapor refrigerant from the first pipe 22 and directs the vapor refrigerant to the second pipe 23, and a bypass pipe 50 through which a liquid refrigerant separated from the first pipe 22 flows.

[0118] According to another aspect of the present disclosure, the length of the first pipe 22 may be equal to or smaller than the length of the second pipe 23.

[0119] According to another aspect of the present disclosure, the condenser 20 may further include a subcooling pipe 24 that cools the liquid refrigerant from the bypass pipe 50.

[0120] According to another aspect of the present disclosure, the air conditioner may include a first valve 28 disposed in the bypass pipe 50.

[0121] According to another aspect of the present disclosure, the first valve 28 may be a check valve that directs a liquid refrigerant from the bypass pipe 50 to the subcooling pipe 24.

[0122] According to another aspect of the present disclosure, the heat exchange pipe 21 may be formed to be longer than the subcooling pipe 24.

[0123] According to another aspect of the present disclosure, the condenser 20 may have a plurality of the heat exchange pipes 21 and a plurality of the bypass pipes 50 configured to form a plurality of passes, and may further include an inlet header 26 into which the refrigerant that has passed through the bypass pipes 50 is introduced, and an inlet pipe 27 that connects the inlet header 26 and the subcooling pipe 24.

[0124] According to another aspect of the present disclosure, the air conditioner may include a first valve 28 disposed in the inlet pipe 27.

[0125] According to another aspect of the present disclosure, the vapor-liquid separating pipe 40 may include an insertion pipe 41 inserted in the first pipe 22, and the insertion pipe 41 may include a tapered portion 42 of which at least a portion is spaced apart from the inner surface of the first pipe 22, and an extending portion 43 that extends from an end of the tapered portion 42.

[0126] According to another aspect of the present disclosure, the tapered portion 42 may be formed to decrease in diameter as it is inserted deeper into the first pipe 22.

[0127] According to another aspect of the present disclosure, the extending portion 43 may be formed to be longer than the tapered portion 42.

[0128] According to another aspect of the present disclosure, the bypass pipe 50 may be connected to one side of the section of the first pipe 22 that surrounds the extending portion 43 and the tapered portion 42.

[0129] According to another aspect of the present disclosure, the bypass pipe 50 may be connected in a direction crossing the longitudinal direction of the first pipe 22.

[0130] According to another aspect of the present disclosure, the refrigerant may be a zeotropic mixture.

[0131] According to another aspect of the present disclosure, the lengths of the first pipe 22 and the second pipe 23 may be set in consideration of the quality of the refrigerant flowing through the heat exchange pipe 21.

[0132] Some embodiments or other embodiments of the present disclosure described above are not exclusive or discriminated from each other. The configurations or functions of some embodiments or other embodiments of the present disclosure described above may be simultaneously used or combined.

[0133] For example, it means that the configuration A described in a specific embodiment and/or the drawings and the configuration B described in another embodiment and/or the drawings may be combined. That is, it means that even if combination of configurations is not directly described, combination is possible unless it is described that combination is impossible.

[0134] The detailed description should not be construed as being limited in all respects and should be construed as an example. The scope of the present disclosure should be determined by reasonable analysis of the claims and all changes within an equivalent range of the present disclosure are included in the scope of the present disclosure.