Air conditioner

Abstract

The present invention relates to an air conditioner. The air conditioner according to an embodiment of the present invention comprises: an outdoor unit including a compressor and an outdoor heat exchanger; a first indoor unit connected to the outdoor unit and including a first heat exchanger and a second heat exchanger; and a second indoor unit connected to the outdoor unit and including an indoor heat exchanger. The first indoor unit may include: a high-pressure guide pipe extending from a high-pressure gas pipe of the outdoor unit and connected to a first inlet port of the first heat exchanger; an extension pipe extending from a first outlet port of the first heat exchanger and connected to a second inlet port of the first heat exchanger; a liquid guide pipe extending from a liquid pipe of the outdoor unit and connected to a second outlet port of the first heat exchanger and a first port of the second heat exchanger; a low-pressure guide pipe extended from a low-pressure gas pipe of the outdoor unit and connected to the second outlet port of the first heat exchanger and a second port of the second heat exchanger; and a first valve device connecting the low-pressure guide pipe and the liquid guide pipe and the second outlet port to each other.

Description

air conditioner

[0001] The present invention relates to an air conditioner.

[0002] An air conditioner is a device that maintains the air in a given space at the most suitable condition for its intended use or purpose. Typically, the air conditioner includes a compressor, a condenser, an expansion device, and an evaporator, and operates a refrigeration cycle that compresses, condenses, expands, and evaporates a refrigerant, thereby cooling or heating the given space.

[0003] The above-mentioned designated space may be proposed in various ways depending on the location where the air conditioner is used. For example, if the air conditioner is placed in a home or office, the above-mentioned designated space may be an indoor space of the home or building.

[0004] When an air conditioner performs 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 an air conditioner performs heating operation, the indoor heat exchanger functions as a condenser, and the outdoor heat exchanger functions as an evaporator.

[0005] The air conditioner can be operated in cooling mode and dehumidifying mode.

[0006] Cooling mode can be understood as a mode that sucks in indoor air, cools it, and then expels it, while dehumidifying mode can be understood as a mode that sucks in indoor air, lowers its humidity, and then expels it.

[0007] When the above dehumidification mode was implemented, the refrigeration cycle operated, resulting in a decrease in humidity and a drop in the temperature of the discharged air. Ultimately, users experienced unwanted cooling, resulting in discomfort.

[0008] Information on prior literature is as follows.

[0009] 1. Publication number (publication date): 10-2019-0088692 (July 29, 2019)

[0010] 2. Name of invention: Multi-type air conditioner

[0011] An embodiment of the present invention aims to provide an air conditioner capable of maintaining a constant temperature of air discharged during dehumidification mode operation.

[0012] An embodiment of the present invention aims to provide an air conditioner capable of increasing the dehumidification amount when operating in a dehumidification mode.

[0013] An embodiment of the present invention aims to provide an air conditioner capable of reducing power consumption by increasing the heat transfer area of ​​a heat exchanger according to indoor load.

[0014] An embodiment of the present invention aims to provide an air conditioner whose heating and cooling capabilities can be improved when performing heating and cooling modes.

[0015] An embodiment of the present invention aims to provide an air conditioner that can be operated in an optimal dehumidification mode based on the temperature and humidity of indoor air.

[0016] An embodiment of the present invention aims to provide an air conditioner with improved versatility by increasing the degree of freedom in installing an outdoor unit and an indoor unit.

[0017] An air conditioner according to the present embodiment includes an outdoor unit including a compressor and an outdoor heat exchanger, a first indoor unit connected to the outdoor unit and including a first heat exchanger and a second heat exchanger, and a second indoor unit connected to the outdoor unit and including an indoor heat exchanger.

[0018] The first indoor unit may include a high-pressure guide pipe extending from the high-pressure engine of the outdoor unit and connected to the first inlet port of the first heat exchanger.

[0019] The first indoor unit may include an extension pipe extending from a first outlet port of the first heat exchanger and connected to a second inlet port of the first heat exchanger.

[0020] The first indoor unit may include a liquid guide pipe extending from the liquid pipe of the outdoor unit and connected to the second outlet port of the first heat exchanger and the first port of the second heat exchanger.

[0021] The first indoor unit may include a low-pressure guide pipe extending from a low-pressure organ of the outdoor unit and connected to a second outlet port of the first heat exchanger and a second port of the second heat exchanger.

[0022] The first indoor unit may include a first valve device that connects the low-pressure guide pipe, the liquid guide pipe, and the second outlet port to each other.

[0023] The above first indoor unit may include a second valve device installed in the extension pipe.

[0024] The first indoor unit may include a third valve device that connects the second valve device, the liquid guide pipe, and the high-pressure guide pipe to each other.

[0025] The above first indoor unit may further include a first expansion device installed in the high-pressure guide pipe.

[0026] The above first indoor unit may further include a first connecting pipe connecting the high-pressure guide pipe and the third valve device.

[0027] A second expansion device may be installed in the above first connecting pipe.

[0028] The first indoor unit may further include a second connecting pipe branched from the liquid guide pipe and connected to a second port of the second heat exchanger.

[0029] A third expansion device may be installed in the above second connecting pipe.

[0030] The above first indoor unit may further include a first flow valve installed in the low-pressure guide pipe.

[0031] The first indoor unit may further include a third connecting pipe connecting the second inlet port of the first heat exchanger and the second port of the second heat exchanger.

[0032] A second flow valve may be installed in the third connecting pipe.

[0033] The first indoor unit may further include a fourth connecting pipe branched from the liquid guide pipe and connected to the third valve device.

[0034] The outdoor unit may include a high-pressure connecting pipe that provides at least a portion of the refrigerant compressed by the compressor to the high-pressure guide pipe.

[0035] The above outdoor unit may further include a four-way valve for sending the refrigerant compressed by the compressor to the outdoor heat exchanger or the low-pressure guide pipe.

[0036] When the air conditioner is in the first mode of operation, the first valve device and the second valve device may be opened, the third valve device may be closed, the first expansion device and the third expansion device may be opened, the second expansion device may be closed, and the first flow valve and the second flow valve may be closed.

[0037] When the air conditioner is in the second mode of operation, the first valve device and the second valve device may be opened, the third valve device may be closed, the first expansion device and the third expansion device may be opened, the second expansion device may be closed, and the first flow valve and the second flow valve may be closed.

[0038] When the air conditioner is in the third mode of operation, the first valve device, the second valve device, and the third valve device may be opened, the first expansion device and the third expansion device may be opened, the second expansion device may be closed, and the first flow valve and the second flow valve may be opened.

[0039] When the air conditioner is in the fourth mode of operation, the first valve device, the second valve device, and the third valve device may be opened, the first expansion device may be closed, the second expansion device and the third expansion device may be opened, the first flow valve may be opened, and the second flow valve may be closed.

[0040] When the air conditioner is in the sixth mode of operation, the first valve device may be closed, the second valve device and the third valve device may be opened, the first expansion device and the third expansion device may be opened, the second expansion device may be closed, and the first flow valve and the second flow valve may be closed.

[0041] When the air conditioner is operated in the seventh mode, the first valve device, the second valve device, and the third valve device may be closed, the first expansion device and the second expansion device may be closed, the third expansion device may be opened, and the first flow valve and the second flow valve may be closed.

[0042] When the air conditioner is in the eighth mode of operation, the first valve device may be opened, the second valve device and the third valve device may be closed, the first expansion device and the second expansion device may be closed, the third expansion device may be opened, and the first flow valve and the second flow valve may be opened.

[0043] The air conditioner may further include a temperature sensor that detects the temperature of air passing through the first indoor unit, a humidity sensor that detects the humidity of air passing through the first indoor unit, and a control unit that controls the operation mode of the air conditioner based on information detected by the temperature sensor and the humidity sensor.

[0044] The control unit can calculate a dew point temperature based on information detected by the temperature sensor and the humidity sensor, and compare the dew point temperature with the temperature of air passing through the second heat exchanger to determine the operation mode of the air conditioner.

[0045] The above control unit can determine the operation mode of the air conditioner by comparing the dew point temperature and the temperature of the air passing through the first heat exchanger.

[0046] According to an embodiment of the present invention, a portion of the refrigerant discharged from the compressor can be bypassed to an indoor heat exchanger and condensed, so that the temperature of the discharged air can be kept constant during dehumidification mode operation, and there is an advantage in that the dehumidification amount increases.

[0047] According to an embodiment of the present invention, the heat transfer area of ​​an indoor heat exchanger can be increased according to the indoor load, so there is an advantage of reducing power consumption due to a high pressure drop.

[0048] According to an embodiment of the present invention, since the flow path of the refrigerant can be changed through multiple valve controls when performing the heating mode and cooling mode, there is an advantage in that the heating capacity and cooling capacity are improved.

[0049] According to an embodiment of the present invention, since it can be operated in an optimal dehumidification mode based on the temperature and humidity of indoor air, there is an advantage in that a comfortable indoor environment can be created.

[0050] According to an embodiment of the present invention, it has the advantage of improved versatility because it can be used not only for a three-pipe outdoor unit but also for a two-pipe outdoor unit.

[0051] According to an embodiment of the present invention, it has the advantage of improved versatility because it can be used not only for a two-pipe indoor unit but also for a three-pipe indoor unit.

[0052] Figure 1 is a cycle diagram showing the configuration of an air conditioner according to a first embodiment of the present invention.

[0053] Figure 2 is a cycle diagram showing the configuration of a first indoor unit according to a first embodiment of the present invention.

[0054] FIG. 3 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the first mode operation of the air conditioner according to the first embodiment of the present invention.

[0055] FIG. 4 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the second mode operation of the air conditioner according to the first embodiment of the present invention.

[0056] FIG. 5 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the third mode operation of the air conditioner according to the first embodiment of the present invention.

[0057] FIG. 6 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the fourth mode operation of the air conditioner according to the first embodiment of the present invention.

[0058] FIG. 7 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the sixth mode operation of the air conditioner according to the first embodiment of the present invention.

[0059] FIG. 8 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the seventh mode operation of the air conditioner according to the first embodiment of the present invention.

[0060] FIG. 9 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the eighth mode operation of the air conditioner according to the first embodiment of the present invention.

[0061] Figure 10 is a psychrometric chart showing a set temperature and humidity range according to the first embodiment of the present invention.

[0062] FIG. 11 is a drawing showing an operation mode corresponding to a set temperature and humidity range according to the first embodiment of the present invention.

[0063] Figure 12 is a flowchart showing a control method of an air conditioner according to the first embodiment of the present invention.

[0064] Fig. 13 is a cycle diagram showing the configuration of an air conditioner according to a second embodiment of the present invention.

[0065] Fig. 14 is a cycle diagram showing the configuration of the first indoor unit according to the second embodiment of the present invention.

[0066] Fig. 15 is a cycle diagram showing the configuration of an air conditioner according to a third embodiment of the present invention.

[0067] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. When designating components in the drawings, it should be noted that, where possible, identical components will be given the same reference numbers even if they appear in different drawings. Furthermore, when describing embodiments of the present invention, if a detailed description of a related known structure or function is deemed to hinder understanding of the embodiments of the present invention, the detailed description will be omitted.

[0068] FIG. 1 is a cycle diagram showing the configuration of an air conditioner according to a first embodiment of the present invention, and FIG. 2 is a cycle diagram showing the configuration of a first indoor unit according to the first embodiment of the present invention.

[0069] Referring to FIGS. 1 and 2, an air conditioner (10) according to a first embodiment of the present invention may include a plurality of components constituting a refrigeration cycle and a refrigerant pipe connecting the plurality of components and guiding the flow of refrigerant.

[0070] The above air conditioner (10) may include an outdoor unit (100) and an indoor unit (200, 300).

[0071] The outdoor unit (100) may be placed outside a building, and the indoor units (200, 300) may be placed inside the building. The indoor units (200, 300) may include multiple indoor units. In this case, the refrigerant pipe may connect the outdoor unit (100) and each of the multiple indoor units (200, 300).

[0072] The above multiple indoor units (200, 300) may include a first indoor unit (200) and a second indoor unit (300).

[0073] The above outdoor unit (100) may include a compressor (110), an outdoor heat exchanger (120), and an outdoor expansion valve (130).

[0074] The above outdoor unit (100) may further include a four-way valve (140) placed on the discharge side of the compressor (110).

[0075] The above outdoor unit (100) may further include an accumulator (150) placed on the suction side of the compressor (110).

[0076] The compressor (110) can compress a gaseous refrigerant into a high-temperature, high-pressure refrigerant. The compressor (110) can include a constant-speed compressor that rotates at a constant speed to compress to a constant capacity, or an inverter compressor that can adjust the compression capacity by varying the rotation speed according to the load.

[0077] The gas-liquid separator (150) may be connected to the suction side of the compressor (110).

[0078] The above-mentioned gas-liquid separator (150) may be configured to filter out liquid refrigerant among the refrigerant sucked into the compressor (110) and send the separated gas-phase refrigerant to the compressor (110).

[0079] The outdoor heat exchanger (120) can be connected to the discharge side of the compressor (110).

[0080] The refrigerant compressed in the compressor (110) may be introduced into the outdoor heat exchanger (120) through the four-way valve (140) and condensed. The outdoor heat exchanger (120) may be provided so that air and refrigerant exchange heat.

[0081] An outdoor fan (125) may be installed on one side of the outdoor heat exchanger (120). The outdoor fan (125) may blow air into the outdoor heat exchanger (120).

[0082] The outdoor expansion valve (130) can be connected to the outlet side of the outdoor heat exchanger (120).

[0083] The above outdoor expansion valve (130) may be configured as an electronic expansion valve (EEV) whose opening can be adjusted. The degree of pressure reduction of the refrigerant can be adjusted according to the opening adjustment of the outdoor expansion valve (130).

[0084] The above air conditioner (10) may further include three pipes (20, 30, 40) connecting the outdoor unit (100) and the indoor unit (200, 300).

[0085] The above three pipes (20, 30, 40) may include a high-pressure pipe (20) through which high-pressure gaseous refrigerant flows, a low-pressure pipe (30) through which low-pressure gaseous refrigerant flows, and a liquid pipe (40) through which liquid refrigerant flows.

[0086] The above outdoor unit (100) and the above indoor unit (200, 300) have a “three-pipe connection structure”, and the refrigerant can circulate through the outdoor unit (100) and the indoor unit (200, 300) through three pipes (20, 30, 40).

[0087] The above outdoor unit (100) may further include a suction pipe (160) that guides the refrigerant discharged from the gas-liquid separator (150) to the suction side of the compressor (110).

[0088] The above outdoor unit (100) may further include a discharge pipe (165) through which the refrigerant compressed in the compressor (110) is discharged.

[0089] The above discharge pipe (165) can connect the suction side of the compressor (110) and the four-way valve (140). The above discharge pipe (165) can extend from the suction side of the compressor (110) to the first port of the four-way valve (140).

[0090] The above outdoor unit (100) may further include a high-pressure connection pipe (170) connecting the discharge pipe (165) and the high-pressure engine (20).

[0091] The above high-pressure connecting pipe (170) may branch from one point of the discharge pipe (165) and extend to the high-pressure engine (20).

[0092] The above outdoor unit (100) may further include a low-pressure connecting pipe (175) connecting the four-way valve (140) and the low-pressure engine (30).

[0093] The above low pressure connecting pipe (175) can be extended from the second port of the four-way valve (140) to the low pressure engine (30).

[0094] The above outdoor unit (100) may further include a heat exchanger connection pipe (180) connecting the four-way valve (140) and the outdoor heat exchanger (120).

[0095] The above heat exchanger connection pipe (180) can be extended from the third port of the four-way valve (140) to the outdoor heat exchanger (120).

[0096] The above outdoor unit (100) may further include a liquid pipe connection pipe (185) connecting the outdoor heat exchanger (120) and the liquid pipe (40).

[0097] The above liquid pipe connection pipe (185) can extend from the outdoor heat exchanger (120) to the liquid pipe (40). The outdoor expansion valve (130) can be installed in the above liquid pipe connection pipe (185).

[0098] The above outdoor unit (100) may further include a return pipe (190) connecting the four-way valve (140) and the gas-liquid separator (150).

[0099] The above return pipe (190) can be extended from the fourth port of the four-way valve (140) to the gas-liquid separator (150).

[0100] When the air conditioner (10) is in the dehumidification mode or heating mode during operation, the valve mode of the four-way valve (140) can be switched to the first valve mode so that the outdoor heat exchanger (120) can function as an evaporator.

[0101] In detail, the air conditioner (10) can control the four-way valve (140) to fluidly connect the first port and the second port of the four-way valve (140), and fluidly connect the third port and the fourth port.

[0102] Accordingly, the refrigerant compressed in the compressor (110) can be introduced into the first port of the four-way valve (140) through the discharge pipe (165) and discharged through the second port. The refrigerant discharged from the four-way valve (140) can be introduced into the indoor unit (200, 300) and condensed.

[0103] When the cooling mode is performed among the operation modes of the above air conditioner (10), the valve mode of the four-way valve (140) can be switched to the second valve mode so that the outdoor heat exchanger (120) can function as a condenser.

[0104] In detail, the air conditioner (10) can control the four-way valve (140) to fluidly connect the first port and the third port of the four-way valve (140), and fluidly connect the second port and the fourth port.

[0105] Accordingly, the refrigerant compressed in the compressor (110) can be introduced into the first port of the four-way valve (140) through the discharge pipe (165) and discharged through the third port. The refrigerant discharged from the four-way valve (140) can be introduced into the outdoor heat exchanger (120) through the heat exchanger connection pipe (180) and condensed.

[0106] The above air conditioner (10) may further include a distributor (50, 60, 70) that connects the outdoor unit (100) and the indoor unit (200, 300).

[0107] The above distributor (50, 60, 70) may include a first distributor (50) connected to the high-pressure engine (20). Some of the refrigerant discharged from the compressor (110) may be introduced into the first distributor (50) and the introduced refrigerant may be distributed to the first indoor unit (200). In addition, the first distributor (50) may be introduced with the refrigerant discharged from the first indoor unit (200) and the introduced refrigerant may be guided to the outdoor unit (100).

[0108] The above air conditioner (10) may further include a first high-pressure engine connecting pipe (51) connecting the first distributor (50) and the first indoor unit (200).

[0109] The above distributor (50, 60, 70) may include a second distributor (60) connected to the low pressure engine (30). The second distributor (60) receives refrigerant discharged from the second port of the four-way valve (140) and distributes the received refrigerant to the first indoor unit (200) or the second indoor unit (300). In addition, the second distributor (60) may guide the refrigerant discharged from the first indoor unit (200) or the second indoor unit (300) to the outdoor unit (100) after the refrigerant is combined.

[0110] The above air conditioner (10) may further include a first low-pressure engine connection pipe (61) connecting the second distributor (60) and the first indoor unit (200).

[0111] The above air conditioner (10) may further include a second low-pressure engine connection pipe (62) connecting the second distributor (60) and the second indoor unit (300).

[0112] The above distributor (50, 60, 70) may include a third distributor (70) connected to the liquid pipe (40). The third distributor (70) receives refrigerant discharged from the outdoor heat exchanger (120) and distributes the received refrigerant to the first indoor unit (200) or the second indoor unit (300). In addition, the third distributor (70) may guide the refrigerant discharged from the first indoor unit (200) or the second indoor unit (300) to the outdoor unit (100) after the refrigerant is combined.

[0113] The above air conditioner (10) may further include a first liquid pipe connection pipe (71) connecting the third distributor (60) and the first indoor unit (200).

[0114] The above air conditioner (10) may further include a second liquid pipe connection pipe (72) connecting the third distributor (60) and the second indoor unit (300).

[0115] The above first indoor unit (200) may include a first heat exchanger (210) and a second heat exchanger (220).

[0116] The first heat exchanger (210) has a refrigerant path formed therein through which refrigerant flows. The first heat exchanger (210) may form a plurality of refrigerant paths. For example, the first heat exchanger (210) may form two independent refrigerant paths. The first heat exchanger (210) may have refrigerant pipes arranged in two rows to form separate refrigerant paths.

[0117] The first heat exchanger (210) may include a plurality of inlet ports through which refrigerant flows in and a plurality of outlet ports through which refrigerant flows out. For example, the first heat exchanger (210) may include two inlet ports and two outlet ports.

[0118] The first heat exchanger (210) may include a first inlet port (211) extending from one side of the first heat exchanger (210) and a first outlet port (212) extending from the other side of the first heat exchanger (210).

[0119] The refrigerant can be introduced into the interior of the first heat exchanger (210) through the first inlet port (211) and then discharged through the first outlet port (212). During this process, the refrigerant can exchange heat with air.

[0120] The first heat exchanger (210) may include a second inlet port (213) extending from one side of the first heat exchanger (210) and a second outlet port (214) extending from the other side of the first heat exchanger (210).

[0121] The refrigerant can be introduced into the interior of the first heat exchanger (210) through the second inlet port (213) and then discharged through the second outlet port (214). During this process, the refrigerant can exchange heat with air.

[0122] The second heat exchanger (220) has a refrigerant path formed therein through which refrigerant flows. The second heat exchanger (220) may be fluidly connected to the first heat exchanger (210). At least a portion of the refrigerant discharged from the first heat exchanger (210) may flow into the second heat exchanger (220).

[0123] The second heat exchanger (220) may include a plurality of ports through which refrigerant is introduced or discharged. For example, the second heat exchanger (220) may include two ports.

[0124] The second heat exchanger (220) may include a first port (221) extending from one side of the second heat exchanger (220) and a second port (222) extending from the other side of the second heat exchanger (220).

[0125] The refrigerant may be introduced into the interior of the second heat exchanger (220) through the first port (221) and then discharged through the second port (222). Alternatively, the refrigerant may be introduced into the interior of the second heat exchanger (220) through the second port (222) and then discharged through the first port (221). During this process, the refrigerant may exchange heat with air.

[0126] An indoor unit fan (215) may be installed on one side of the first heat exchanger (210) and the second heat exchanger (220). The indoor unit fan (215) may blow air to the first heat exchanger (210) and the second heat exchanger (220).

[0127] When the above indoor unit fan (215) operates, the indoor air can first pass through the second heat exchanger (220) and then pass through the first heat exchanger (210).

[0128] The first indoor unit (200) may further include a high-pressure guide pipe (231) extending from the high-pressure engine (20) and connected to the first heat exchanger (210).

[0129] The above high-pressure guide pipe (231) can connect the first high-pressure engine connection pipe (51) and the first inlet port (211) of the first heat exchanger (210).

[0130] The above first indoor unit (200) may further include a first expansion device (271) installed in the high-pressure guide pipe (231).

[0131] The above first expansion device (271) may be configured as an electronic expansion valve (EEV) whose opening can be adjusted. The degree of pressure reduction of the refrigerant can be adjusted according to the opening adjustment of the first expansion device (271).

[0132] The first indoor unit (200) may further include a low-pressure guide pipe (241) extending from the low-pressure engine (30) and connected to the first heat exchanger (210) and the second heat exchanger (220), respectively.

[0133] The above low-pressure guide pipe (241) can connect the first low-pressure engine connection pipe (61), the second outlet port (214) of the first heat exchanger (210), and the first port (221) of the second heat exchanger (220), respectively.

[0134] The above first indoor unit (200) may further include a first flow valve (281) installed in the low-pressure guide pipe (241).

[0135] The first flow valve (281) can restrict the flow of refrigerant through an opening and closing operation. For example, the first flow valve (281) can be configured as a solenoid valve.

[0136] The first indoor unit (200) may further include a liquid guide pipe (251) extending from the liquid pipe (40) and connected to the first heat exchanger (210).

[0137] The above liquid guide pipe (251) can connect the first liquid pipe connection pipe (71) and the second outlet port (214) of the first heat exchanger (210).

[0138] The first indoor unit (200) may further include a first valve device (291) connected to the second outlet port (214) of the first heat exchanger (210). The first valve device (291) may be configured as a three-way valve.

[0139] The first valve device (291) may be positioned at a point where the low-pressure guide pipe (241), the liquid guide pipe (251), and the second outlet port (241) are connected to each other. The first valve device (291) may connect an end of the low-pressure guide pipe (241), an end of the liquid guide pipe (251), and an end of the second outlet port (241).

[0140] The first indoor unit (200) may further include a second valve device (293) connecting the first outlet port (212) and the second inlet port (213) of the first heat exchanger (210). The second valve device (293) may be configured as a three-way valve.

[0141] The above second valve device (293) can be installed in a pipe connecting the first outlet port (212) and the second inlet port (213).

[0142] The first indoor unit (200) may further include a first connecting pipe (261) branched from the high-pressure guide pipe (231) and connected to the liquid guide pipe (251).

[0143] The above first indoor unit (200) may further include a second expansion device (273) installed in the first connecting pipe (261).

[0144] The second expansion device (273) may be configured as an electronic expansion valve (EEV) whose opening can be adjusted. The degree of pressure reduction of the refrigerant can be adjusted according to the opening adjustment of the second expansion device (273).

[0145] The first indoor unit (200) may further include a third valve device (295) connected to the first connecting pipe (261). The third valve device (295) may be configured as a three-way valve.

[0146] The third valve device (295) may be positioned at a point where the liquid guide pipe (251), the first connecting pipe (261), and the second valve device (293) are connected to each other. The third valve device (295) may connect a pipe branched from the liquid guide pipe (251), a pipe extending from the second valve device (293), and an end of the first connecting pipe (261).

[0147] The first indoor unit (200) may further include a second connecting pipe (262) branched from the liquid guide pipe (251) and connected to the second heat exchanger (220).

[0148] The above second connecting pipe (262) can extend from the first branch point (251a) of the liquid guide pipe (251) to the first port (222) of the second heat exchanger (220).

[0149] The above first indoor unit (200) may further include a third expansion device (275) installed in the second connecting pipe (262).

[0150] The third expansion device (276) may be configured as an electronic expansion valve (EEV) whose opening can be adjusted. The degree of pressure reduction of the refrigerant can be adjusted according to the opening adjustment of the third expansion device (275).

[0151] The first indoor unit (200) may further include a third connecting pipe (263) connecting the second inlet port (213) of the first heat exchanger (210) and the second port (222) of the second heat exchanger (220).

[0152] The third connecting pipe (263) may be branched from the second connecting pipe (262) and extended to the second inlet port (213).

[0153] The above first indoor unit (200) may further include a second flow valve (285) installed in the third connecting pipe (263).

[0154] The second flow valve (285) can restrict the flow of refrigerant through an opening and closing operation. For example, the second flow valve (285) can be configured as a solenoid valve.

[0155] The above first indoor unit (200) may further include a fourth connecting pipe (264) branched from the liquid guide pipe (251) and connected to the third valve device (295).

[0156] The above fourth connecting pipe (264) can be extended from the second branch point (251b) of the liquid guide pipe (251) to the third valve device (295).

[0157] The above first indoor unit (200) may further include a fifth connecting pipe (265) connecting the second valve device (293) and the third valve device (295).

[0158] The above second indoor unit (300) may include an indoor heat exchanger (310).

[0159] The above indoor heat exchanger (310) may be provided to allow heat exchange between air and refrigerant. The above indoor heat exchanger (310) may function as an evaporator or a condenser depending on the operating mode of the air conditioner (10).

[0160] An indoor unit fan (315) may be installed on one side of the indoor heat exchanger (310). The indoor unit fan (315) may blow air into the indoor heat exchanger (310).

[0161] The above second indoor unit (300) may further include an indoor expansion device (320) provided on the inlet side of the indoor heat exchanger (310).

[0162] The above indoor expansion device (320) may be configured with an electronic expansion valve (EEV) whose opening can be adjusted. The degree of depressurization of the refrigerant can be adjusted according to the opening adjustment of the indoor expansion device (320).

[0163] One side of the second indoor unit (300) may be connected to the second low-pressure engine connection pipe (62), and the other side of the second indoor unit (300) may be connected to the second liquid pipe connection pipe (72). The second low-pressure engine connection pipe (62) may be connected to the indoor heat exchanger (310), and the second liquid pipe connection pipe (72) may be connected to the indoor expansion device (320).

[0164] The above air conditioner (10) may include a first temperature sensor (201) that detects the temperature of air sucked into the first indoor unit (200). For example, the first temperature sensor (201) may be placed on the air suction side of the second heat exchanger (220).

[0165] The above air conditioner (10) may include a humidity sensor (203) that detects the humidity of air sucked into the first indoor unit (200). For example, the humidity sensor (203) may be placed on the air suction side of the second heat exchanger (220).

[0166] The above air conditioner (10) may include a second temperature sensor (205) that detects the temperature of air passing through the second heat exchanger (220). For example, the second temperature sensor (205) may be placed on the air discharge side of the second heat exchanger (220) or the air intake side of the first heat exchanger (210).

[0167] The above air conditioner (10) may include a third temperature sensor (207) that detects the temperature of air taken out from the first indoor unit (200). For example, the third temperature sensor (207) may be placed on the air discharge side of the first heat exchanger (210) or the discharge side of the indoor unit fan (215).

[0168] The above air conditioner (10) may include a control unit that controls the operation mode of the air conditioner based on information detected by the temperature sensor and humidity sensor.

[0169] The above control unit can calculate the dew point temperature based on information detected by the temperature sensor and humidity sensor, and control a plurality of valves using the dew point temperature.

[0170] The above air conditioner (10) can be operated in any one of heating mode, cooling mode, and dehumidification mode.

[0171] The heating mode can be understood as a mode in which the outdoor unit (100) functions as an evaporator, the first heat exchanger (210), the second heat exchanger (220), and the indoor heat exchanger (310) function as condensers, and the heated air is discharged from the first indoor unit (200) and the second indoor unit (300).

[0172] The cooling mode can be understood as a mode in which the outdoor unit (100) functions as a condenser and the first heat exchanger (210), the second heat exchanger (220) and the indoor heat exchanger (310) function as evaporators, and in which air cooled in the first indoor unit (200) and the second indoor unit (300) is discharged.

[0173] The dehumidification mode can be understood as a mode in which the outdoor unit (100) and the first heat exchanger (210) function as condensers, and the second heat exchanger (220) and the indoor heat exchanger (310) function as evaporators, and in which constant temperature dehumidified air is discharged from the first indoor unit (200) and cooled air is discharged from the second indoor unit (300).

[0174] In addition, the air conditioner (10) can be operated in a partial mode (partial heating mode, partial cooling mode, cooling / dehumidification mode) that partially uses the heat exchanger by utilizing two independent refrigerant passages of the first heat exchanger (210). The air conditioner (10) can use at least a portion of the heat exchanger (load) of the first heat exchanger (210) depending on the indoor load. The air conditioner (10) can control a valve to switch to various operation modes depending on the indoor load.

[0175] FIG. 3 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the first mode operation of the air conditioner according to the first embodiment of the present invention.

[0176] Referring to FIGS. 1 and 3 together, when the air conditioner (10) is operated in the first mode (high heating mode), the valve mode of the four-way valve (140) can be switched to the first valve mode so that the outdoor heat exchanger (120) can function as an evaporator and the first heat exchanger (210), the second heat exchanger (220) and the indoor heat exchanger (310) can function as condensers.

[0177] At this time, the first valve device (291) and the second valve device (293) may be opened, and the third valve device (295) may be closed. The first expansion device (271) and the third expansion device (275) may be opened, and the second expansion device (273) may be closed. The first flow valve (281) and the second flow valve (285) may be closed.

[0178] In detail, the air conditioner (10) can control the four-way valve (140) to fluidly connect the first port and the second port of the four-way valve (140), and fluidly connect the third port and the fourth port.

[0179] Accordingly, some of the refrigerant compressed in the compressor (110) may flow through the high-pressure engine (20) along the high-pressure connecting pipe (170) and then flow into the first indoor unit (200) through the first distributor (50).

[0180] The refrigerant introduced into the first indoor unit (200) through the first high-pressure engine connecting pipe (51) can be condensed by passing through the first expansion device (271) along the high-pressure guide pipe (231) and then introduced into the first inlet port (211) of the first heat exchanger (210).

[0181] The refrigerant discharged through the first outlet port (212) of the first heat exchanger (210) can be further condensed by flowing into the second inlet port (213) of the first heat exchanger (210) through the second valve device (293).

[0182] The refrigerant discharged through the second outlet port (214) of the first heat exchanger (210) can be introduced into the liquid guide pipe (251) through the first valve device (291) and then discharged from the first indoor unit (200) through the first liquid pipe connection pipe (71).

[0183] Meanwhile, the remaining portion of the refrigerant compressed in the compressor (110) may flow into the first port of the four-way valve (140) along the discharge pipe (165) and be discharged through the second port. The refrigerant discharged from the four-way valve (140) may flow through the low-pressure engine (30) along the low-pressure connection pipe (175) and then be distributed and introduced into the first indoor unit (200) and the second indoor unit (300) through the second distributor (60).

[0184] The refrigerant that flows into the first indoor unit (200) through the first low-pressure engine connecting pipe (61) can flow into the first port (221) of the second heat exchanger (220) along the low-pressure guide pipe (241) and be condensed.

[0185] The refrigerant discharged through the second port (222) of the second heat exchanger (220) can be introduced into the liquid guide pipe (251) through the third expansion device (275) and then discharged from the first indoor unit (200) through the first liquid pipe connecting pipe (71).

[0186] The refrigerant introduced into the second indoor unit (300) through the second low-pressure engine connecting pipe (62) may be introduced into the indoor heat exchanger (310) and condensed. The refrigerant discharged from the indoor heat exchanger (310) may be discharged from the second indoor unit (300) through the indoor expansion device (320).

[0187] The refrigerant discharged from the first indoor unit (200) and the second indoor unit (300) is combined in the liquid pipe (40) and then introduced into the outdoor unit (100). The refrigerant introduced into the outdoor unit (100) may be introduced into the outdoor expansion valve (130) along the liquid pipe connection pipe (185), depressurized, and then evaporated in the outdoor heat exchanger (120). The refrigerant discharged from the outdoor heat exchanger (120) is introduced into the third port of the four-way valve (140) along the heat exchanger connection pipe (180) and then discharged through the fourth port.

[0188] The refrigerant discharged from the above four-way valve (140) flows into the gas-liquid separator (150) along the return pipe (190). The gaseous refrigerant separated by passing through the gas-liquid separator (150) can be sucked into the compressor (110) through the suction pipe (160).

[0189] This circulation of refrigerant can be repeated.

[0190] The above first mode can be called a “high heating mode” in that it uses both the heat transfer parts of the first heat exchanger (210) and the second heat exchanger (220) as condensers.

[0191] FIG. 4 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the second mode operation of the air conditioner according to the first embodiment of the present invention.

[0192] Referring to FIGS. 1 and 4 together, when the air conditioner (10) is operated in the second mode (constant temperature dehumidification mode), the valve mode of the four-way valve (140) can be switched to the second valve mode so that the outdoor heat exchanger (120) and the first heat exchanger (210) can function as condensers, and the second heat exchanger (220) and the indoor heat exchanger (310) can function as evaporators.

[0193] At this time, the first valve device (291) and the second valve device (293) may be opened, and the third valve device (295) may be closed. The first expansion device (271) and the third expansion device (275) may be opened, and the second expansion device (273) may be closed. The first flow valve (281) and the second flow valve (285) may be closed.

[0194] In detail, the air conditioner (10) can control the four-way valve (140) to fluidly connect the first port and the third port of the four-way valve (140), and fluidly connect the second port and the fourth port.

[0195] Accordingly, some of the refrigerant compressed in the compressor (110) may flow through the high-pressure engine (20) along the high-pressure connecting pipe (170) and then flow into the first indoor unit (200) through the first distributor (50).

[0196] The refrigerant introduced into the first indoor unit (200) through the first high-pressure engine connecting pipe (51) can be condensed by passing through the first expansion device (271) along the high-pressure guide pipe (231) and then introduced into the first inlet port (211) of the first heat exchanger (210).

[0197] The refrigerant discharged through the first outlet port (212) of the first heat exchanger (210) can be condensed by flowing into the second inlet port (213) of the first heat exchanger (210) through the second valve device (293).

[0198] The refrigerant discharged through the second outlet port (214) of the first heat exchanger (210) flows into the liquid guide pipe (251) through the first valve device (291) and then flows to the first branch point (251a) of the liquid guide pipe (251).

[0199] Meanwhile, the remaining portion of the refrigerant compressed in the compressor (110) may be introduced into the first port of the four-way valve (140) along the discharge pipe (165) and discharged through the third port. The refrigerant discharged from the four-way valve (140) may be introduced into the outdoor heat exchanger (120) and condensed.

[0200] The refrigerant discharged from the outdoor heat exchanger (120) can be discharged from the outdoor unit (100) through the liquid pipe (40) by passing through the outdoor expansion valve (130). The refrigerant discharged from the outdoor unit (100) can be distributed and introduced into the first indoor unit (200) and the second indoor unit (300) through the third distributor (70).

[0201] The refrigerant introduced into the first indoor unit (200) through the first liquid pipe connecting pipe (71) flows along the liquid guide pipe (251) to the first branch point (251a).

[0202] The refrigerant flowing to the first branch point (251a) is combined and then depressurized through the third expansion device (275) and flows into the second port (222) of the second heat exchanger (220) to be evaporated.

[0203] The refrigerant discharged through the first port (221) of the second heat exchanger (220) can be discharged from the first indoor unit (200) through the low-pressure guide pipe (241). The refrigerant discharged from the first indoor unit (200) is introduced into the low-pressure engine (30) through the second distributor (60).

[0204] The refrigerant introduced into the second indoor unit (300) through the second liquid pipe connection (72) may be introduced into the indoor expansion valve (320), depressurized, and then evaporated in the indoor heat exchanger (310). The refrigerant discharged from the indoor heat exchanger (310) is introduced into the low-pressure engine (30) through the second distributor (60).

[0205] The refrigerant introduced into the low-pressure device (30) is combined and then introduced into the outdoor unit (100). The refrigerant introduced into the outdoor unit (100) flows through the low-pressure connecting pipe (175) into the second port of the four-way valve (140) and is then discharged through the fourth port.

[0206] The refrigerant discharged from the above four-way valve (140) flows into the gas-liquid separator (150) along the return pipe (190). The gaseous refrigerant separated by passing through the gas-liquid separator (150) can be sucked into the compressor (110) through the suction pipe (160).

[0207] This circulation of refrigerant can be repeated.

[0208] The above second mode can be called a “constant temperature dehumidification mode” in that the first heat exchanger (210) functions as a condenser and the second heat exchanger (220) functions as an evaporator.

[0209] FIG. 5 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the third mode operation of the air conditioner according to the first embodiment of the present invention.

[0210] Referring to FIG. 1 and FIG. 5 together, when the air conditioner (10) is operated in the third mode (partial dehumidification mode or cooling / dehumidification mode), the valve mode of the four-way valve (140) can be switched to the second valve mode so that the outdoor heat exchanger (120) can function as a condenser and the second heat exchanger (220) and the indoor heat exchanger (310) can function as evaporators.

[0211] The first heat exchanger (210) may have a part of the heat exchange section (e.g., row 1) function as a condenser, and the remaining part (e.g., row 2) function as an evaporator.

[0212] At this time, some ports of the first valve device (291), the second valve device (293), and the third valve device (295) may be opened. The first expansion device (271) and the third expansion device (275) may be opened, and the second expansion device (273) may be closed. The first flow valve (281) and the second flow valve (285) may be opened.

[0213] In detail, the air conditioner (10) can control the four-way valve (140) to fluidly connect the first port and the third port of the four-way valve (140), and fluidly connect the second port and the fourth port.

[0214] Accordingly, some of the refrigerant compressed in the compressor (110) may flow through the high-pressure engine (20) along the high-pressure connecting pipe (170) and then flow into the first indoor unit (200) through the first distributor (50).

[0215] The refrigerant introduced into the first indoor unit (200) through the first high-pressure engine connecting pipe (51) can be condensed by passing through the first expansion device (271) along the high-pressure guide pipe (231) and then introduced into the first inlet port (211) of the first heat exchanger (210).

[0216] The refrigerant discharged through the first outlet port (212) of the first heat exchanger (210) flows into the third valve device (295) through the second valve device (293).

[0217] Here, the port of the second valve device (293) connected to the second inlet port (213) can be closed.

[0218] The refrigerant discharged from the third valve device (295) flows into the liquid guide pipe (251) and then to the first branch point (251a) of the liquid guide pipe (251).

[0219] Here, the port of the third valve device (295) connected to the first connecting pipe (261) can be closed.

[0220] Meanwhile, the remaining portion of the refrigerant compressed in the compressor (110) may be introduced into the first port of the four-way valve (140) along the discharge pipe (165) and discharged through the third port. The refrigerant discharged from the four-way valve (140) may be introduced into the outdoor heat exchanger (120) and condensed.

[0221] The refrigerant discharged from the outdoor heat exchanger (120) can be discharged from the outdoor unit (100) through the liquid pipe (40) by passing through the outdoor expansion valve (130). The refrigerant discharged from the outdoor unit (100) can be distributed and introduced into the first indoor unit (200) and the second indoor unit (300) through the third distributor (70).

[0222] The refrigerant introduced into the first indoor unit (200) through the first liquid pipe connecting pipe (71) flows along the liquid guide pipe (251) to the first branch point (251a).

[0223] The refrigerant flowing to the first branch point (251a) is combined and then flows into the third expansion device (275) and is depressurized.

[0224] Some of the refrigerant discharged from the third expansion device (275) may be introduced into the second inlet port (213) of the first heat exchanger (210) through the second flow valve (285) and evaporated. The refrigerant discharged into the second outlet port (214) of the first heat exchanger (210) is introduced into the low-pressure guide pipe (241) through the first valve device (291) and the first flow valve (281).

[0225] Here, the port of the first valve device (291) connected to the liquid guide pipe (251) can be closed.

[0226] The remaining portion of the refrigerant discharged from the third expansion device (275) may be introduced into the second port (222) of the second heat exchanger (220) and evaporated. The refrigerant discharged through the first outlet port (221) of the second heat exchanger (220) is introduced into the low-pressure guide pipe (241).

[0227] The refrigerant introduced into the low-pressure guide pipe (241) can be combined and then discharged from the first indoor unit (200). The refrigerant discharged from the first indoor unit (200) is introduced into the low-pressure engine (30) through the second distributor (60).

[0228] The refrigerant introduced into the second indoor unit (300) through the second liquid pipe connection (72) may be introduced into the indoor expansion valve (320), depressurized, and then evaporated in the indoor heat exchanger (310). The refrigerant discharged from the indoor heat exchanger (310) is introduced into the low-pressure engine (30) through the second distributor (60).

[0229] The refrigerant introduced into the low-pressure device (30) is combined and then introduced into the outdoor unit (100). The refrigerant introduced into the outdoor unit (100) flows through the low-pressure connecting pipe (175) into the second port of the four-way valve (140) and is then discharged through the fourth port.

[0230] The refrigerant discharged from the above four-way valve (140) flows into the gas-liquid separator (150) along the return pipe (190). The gaseous refrigerant separated by passing through the gas-liquid separator (150) can be sucked into the compressor (110) through the suction pipe (160).

[0231] This circulation of refrigerant can be repeated.

[0232] The above third mode may be called a “partial dehumidification mode” or a “cooling dehumidification mode” in that a part of the first heat exchanger (210) functions as a condenser and the remaining part of the first heat exchanger (210) and the second heat exchanger (220) function as an evaporator.

[0233] FIG. 6 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the fourth mode operation of the air conditioner according to the first embodiment of the present invention.

[0234] Referring to FIG. 1 and FIG. 6 together, when the air conditioner (10) is operated in the fourth mode (high cooling mode), the valve mode of the four-way valve (140) can be switched to the second valve mode so that the outdoor heat exchanger (120) can function as a condenser and the first heat exchanger (210), the second heat exchanger (220) and the indoor heat exchanger (310) can function as evaporators.

[0235] At this time, the first valve device (291), the second valve device (293), and the third valve device (295) can be opened. The first expansion device (271) can be closed, and the second expansion device (273) and the third expansion device (275) can be opened. The first flow valve (281) can be opened, and the second flow valve (285) can be closed.

[0236] In detail, the air conditioner (10) can control the four-way valve (140) to fluidly connect the first port and the third port of the four-way valve (140), and fluidly connect the second port and the fourth port.

[0237] Accordingly, the refrigerant compressed in the compressor (110) can be introduced into the first port of the four-way valve (140) along the discharge pipe (165) and discharged through the third port. The refrigerant discharged from the four-way valve (140) can be introduced into the outdoor heat exchanger (120) and condensed.

[0238] The refrigerant discharged from the outdoor heat exchanger (120) can be discharged from the outdoor unit (100) through the liquid pipe (40) by passing through the outdoor expansion valve (130). The refrigerant discharged from the outdoor unit (100) can be distributed and introduced into the first indoor unit (200) and the second indoor unit (300) through the third distributor (70).

[0239] The refrigerant introduced into the first indoor unit (200) through the first liquid pipe connecting pipe (71) flows along the liquid guide pipe (251) to the first branch point (251a).

[0240] Some of the refrigerant flowing to the first branch point (251a) may flow into the first connecting pipe (261) through the third valve device (295).

[0241] Here, the port of the third valve device (295) connected to the second valve device (293) can be closed.

[0242] The refrigerant of the first connecting pipe (261) may be introduced into the second expansion valve (273), depressurized, and then introduced into the first inlet port (211) of the first heat exchanger (210) to be evaporated.

[0243] The refrigerant discharged through the first outlet port (212) of the first heat exchanger (210) can be further evaporated by flowing into the second inlet port (213) of the first heat exchanger (210) through the second valve device (293).

[0244] Here, the port of the second valve device (293) connected to the third valve device (295) can be closed.

[0245] The refrigerant discharged through the second outlet port (214) of the first heat exchanger (210) can be introduced into the low-pressure guide pipe (241) through the first valve device (291) and the first flow valve (281).

[0246] The remaining portion of the refrigerant that has flowed to the first branch point (251a) may be introduced into the third expansion device (275), depressurized, and introduced into the second port (222) of the second heat exchanger (220) to be evaporated. The refrigerant discharged into the first port (221) of the second heat exchanger (220) may be introduced into the low-pressure guide pipe (241).

[0247] The refrigerant introduced into the low-pressure guide pipe (241) can be combined and then discharged from the first indoor unit (200). The refrigerant discharged from the first indoor unit (200) is introduced into the low-pressure engine (30) through the second distributor (60).

[0248] The refrigerant introduced into the second indoor unit (300) through the second liquid pipe connection (72) may be introduced into the indoor expansion valve (320), depressurized, and then evaporated in the indoor heat exchanger (310). The refrigerant discharged from the indoor heat exchanger (310) is introduced into the low-pressure engine (30) through the second distributor (60).

[0249] The refrigerant introduced into the low-pressure device (30) is combined and then introduced into the outdoor unit (100). The refrigerant introduced into the outdoor unit (100) flows through the low-pressure connecting pipe (175) into the second port of the four-way valve (140) and is then discharged through the fourth port.

[0250] The refrigerant discharged from the above four-way valve (140) flows into the gas-liquid separator (150) along the return pipe (190). The gaseous refrigerant separated by passing through the gas-liquid separator (150) can be sucked into the compressor (110) through the suction pipe (160).

[0251] This circulation of refrigerant can be repeated.

[0252] The above-mentioned fourth mode can be called a “high cooling mode” in that it uses both the heat transfer parts of the first heat exchanger (210) and the second heat exchanger (220) as evaporators.

[0253] FIG. 7 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the sixth mode operation of the air conditioner according to the first embodiment of the present invention.

[0254] Referring to FIG. 1 and FIG. 7 together, when the air conditioner (10) is operated in the sixth mode (partial heating mode), the valve mode of the four-way valve (140) can be switched to the first valve mode so that the outdoor heat exchanger (120) can function as an evaporator and the first heat exchanger (210), the second heat exchanger (220) and the indoor heat exchanger (310) can function as condensers.

[0255] At this time, the first valve device (291) may be closed, and the second valve device (293) and the third valve device (295) may be opened. The first expansion device (271) and the third expansion device (275) may be opened, and the second expansion device (275) may be closed. The first flow valve (281) and the second flow valve (285) may be closed.

[0256] In detail, the air conditioner (10) can control the four-way valve (140) to fluidly connect the first port and the second port of the four-way valve (140), and fluidly connect the third port and the fourth port.

[0257] Accordingly, some of the refrigerant compressed in the compressor (110) may flow through the high-pressure engine (20) along the high-pressure connecting pipe (170) and then flow into the first indoor unit (200) through the first distributor (50).

[0258] The refrigerant introduced into the first indoor unit (200) through the first high-pressure engine connecting pipe (51) can be condensed by passing through the first expansion device (271) along the high-pressure guide pipe (231) and then introduced into the first inlet port (211) of the first heat exchanger (210).

[0259] The refrigerant discharged through the first outlet port (212) of the first heat exchanger (210) can flow into the third valve device (295) through the second valve device (293). The refrigerant discharged from the third valve device (295) flows into the liquid guide pipe (251).

[0260] Meanwhile, the remaining portion of the refrigerant compressed in the compressor (110) may flow into the first port of the four-way valve (140) along the discharge pipe (165) and be discharged through the second port. The refrigerant discharged from the four-way valve (140) may flow through the low-pressure engine (30) along the low-pressure connection pipe (175) and then be distributed and introduced into the first indoor unit (200) and the second indoor unit (300) through the second distributor (60).

[0261] The refrigerant introduced into the first indoor unit (200) through the first low-pressure engine connecting pipe (61) may be condensed by flowing into the first port (221) of the second heat exchanger (220) along the low-pressure guide pipe (241). The refrigerant discharged through the second port (222) of the second heat exchanger (220) is introduced into the liquid guide pipe (251) through the third expansion device (275).

[0262] The refrigerant introduced into the liquid guide pipe (251) can be combined and then discharged from the first indoor unit (200) through the first liquid pipe connection pipe (71). The refrigerant discharged from the first indoor unit (200) is introduced into the liquid pipe (40) through the third distributor (70).

[0263] The refrigerant introduced into the second indoor unit (300) through the second low-pressure engine connecting pipe (62) may be introduced into the indoor heat exchanger (310) and condensed. The refrigerant discharged from the indoor heat exchanger (310) may be discharged from the second indoor unit (300) through the indoor expansion device (320).

[0264] The refrigerant discharged from the first indoor unit (200) and the second indoor unit (300) is combined in the liquid pipe (40) and then introduced into the outdoor unit (100). The refrigerant introduced into the outdoor unit (100) may be introduced into the outdoor expansion valve (130) along the liquid pipe connection pipe (185), depressurized, and then evaporated in the outdoor heat exchanger (120). The refrigerant discharged from the outdoor heat exchanger (120) is introduced into the third port of the four-way valve (140) along the heat exchanger connection pipe (180) and then discharged through the fourth port.

[0265] The refrigerant discharged from the above four-way valve (140) flows into the gas-liquid separator (150) along the return pipe (190). The gaseous refrigerant separated by passing through the gas-liquid separator (150) can be sucked into the compressor (110) through the suction pipe (160).

[0266] This circulation of refrigerant can be repeated.

[0267] The above-mentioned sixth mode can be called a “partial heating mode” in that a part of the first heat exchanger (210) functions as a condenser and the second heat exchanger (220) functions as a condenser.

[0268] FIG. 8 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the seventh mode operation of the air conditioner according to the first embodiment of the present invention.

[0269] Referring to FIG. 1 and FIG. 8 together, when the air conditioner (10) is operated in the seventh mode (weak cooling mode), the valve mode of the four-way valve (140) can be switched to the second valve mode so that the outdoor heat exchanger (120) can function as a condenser and the second heat exchanger (220) and the indoor heat exchanger (310) can function as evaporators.

[0270] Refrigerant does not flow through the first heat exchanger (210). That is, the first heat exchanger (210) is not used.

[0271] At this time, the first valve device (291), the second valve device (293), and the third valve device (295) can be closed. The first expansion device (271) and the second expansion device (273) can be closed, and the third expansion device (275) can be opened. The first flow valve (281) and the second flow valve (285) can be closed.

[0272] In detail, the air conditioner (10) can control the four-way valve (140) to fluidly connect the first port and the third port of the four-way valve (140), and fluidly connect the second port and the fourth port.

[0273] Accordingly, the refrigerant compressed in the compressor (110) can be introduced into the first port of the four-way valve (140) along the discharge pipe (165) and discharged through the third port. The refrigerant discharged from the four-way valve (140) can be introduced into the outdoor heat exchanger (120) and condensed.

[0274] The refrigerant discharged from the outdoor heat exchanger (120) can be discharged from the outdoor unit (100) through the liquid pipe (40) by passing through the outdoor expansion valve (130). The refrigerant discharged from the outdoor unit (100) can be distributed and introduced into the first indoor unit (200) and the second indoor unit (300) through the third distributor (70).

[0275] The refrigerant introduced into the first indoor unit (200) through the first liquid pipe connecting pipe (71) flows along the liquid guide pipe (251) to the first branch point (251a). Then, the refrigerant is introduced into the third expansion device (275), depressurized, and then introduced into the second port (222) of the second heat exchanger (220) to be evaporated.

[0276] The refrigerant discharged through the first port (221) of the second heat exchanger (220) may be discharged from the first indoor unit (200) after flowing into the low-pressure guide pipe (241). The refrigerant discharged from the first indoor unit (200) flows into the low-pressure engine (30) through the second distributor (60).

[0277] The refrigerant introduced into the second indoor unit (300) through the second liquid pipe connection (72) may be introduced into the indoor expansion valve (320), depressurized, and then evaporated in the indoor heat exchanger (310). The refrigerant discharged from the indoor heat exchanger (310) is introduced into the low-pressure engine (30) through the second distributor (60).

[0278] The refrigerant introduced into the low-pressure device (30) is combined and then introduced into the outdoor unit (100). The refrigerant introduced into the outdoor unit (100) flows through the low-pressure connecting pipe (175) into the second port of the four-way valve (140) and is then discharged through the fourth port.

[0279] The refrigerant discharged from the above four-way valve (140) flows into the gas-liquid separator (150) along the return pipe (190). The gaseous refrigerant separated by passing through the gas-liquid separator (150) can be sucked into the compressor (110) through the suction pipe (160).

[0280] This circulation of refrigerant can be repeated.

[0281] The above-mentioned seventh mode can be called a “weak cooling mode” in that it uses only the second heat exchanger (220) as an evaporator.

[0282] FIG. 9 is a cycle diagram of the first indoor unit showing the refrigerant flow pattern during the eighth mode operation of the air conditioner according to the first embodiment of the present invention.

[0283] Referring to FIG. 1 and FIG. 9 together, when the air conditioner (10) is operated in the eighth mode (partial cooling mode), the valve mode of the four-way valve (140) can be switched to the second valve mode so that the outdoor heat exchanger (120) can function as a condenser and the first heat exchanger (210), the second heat exchanger (220) and the indoor heat exchanger (310) can function as evaporators.

[0284] At this time, the first valve device (291) may be opened, and the second valve device (293) and the third valve device (295) may be closed. The first expansion device (271) and the second expansion device (273) may be closed, and the third expansion device (275) may be opened. The first flow valve (281) and the second flow valve (285) may be opened.

[0285] In detail, the air conditioner (10) can control the four-way valve (140) to fluidly connect the first port and the third port of the four-way valve (140), and fluidly connect the second port and the fourth port.

[0286] Accordingly, the refrigerant compressed in the compressor (110) can be introduced into the first port of the four-way valve (140) along the discharge pipe (165) and discharged through the third port. The refrigerant discharged from the four-way valve (140) can be introduced into the outdoor heat exchanger (120) and condensed.

[0287] The refrigerant discharged from the outdoor heat exchanger (120) can be discharged from the outdoor unit (100) through the liquid pipe (40) by passing through the outdoor expansion valve (130). The refrigerant discharged from the outdoor unit (100) can be distributed and introduced into the first indoor unit (200) and the second indoor unit (300) through the third distributor (70).

[0288] The refrigerant introduced into the first indoor unit (200) through the first liquid pipe connecting pipe (71) flows along the liquid guide pipe (251) to the first branch point (251a) and is introduced into the third expansion device (275) to be depressurized.

[0289] Some of the refrigerant discharged from the third expansion device (275) may be introduced into the second inlet port (213) of the first heat exchanger (210) through the second flow valve (285) and evaporated. The refrigerant discharged into the second outlet port (214) of the first heat exchanger (210) is introduced into the low-pressure guide pipe (241) through the first valve device (291) and the first flow valve (281).

[0290] The remaining portion of the refrigerant discharged from the third expansion device (275) may be introduced into the second port (222) of the second heat exchanger (220) and evaporated. The refrigerant discharged into the first port (221) of the second heat exchanger (220) is introduced into the low-pressure guide pipe (241).

[0291] The refrigerant introduced into the low-pressure guide pipe (241) can be combined and then discharged from the first indoor unit (200). The refrigerant discharged from the first indoor unit (200) is introduced into the low-pressure engine (30) through the second distributor (60).

[0292] The refrigerant introduced into the second indoor unit (300) through the second liquid pipe connection (72) may be introduced into the indoor expansion valve (320), depressurized, and then evaporated in the indoor heat exchanger (310). The refrigerant discharged from the indoor heat exchanger (310) is introduced into the low-pressure engine (30) through the second distributor (60).

[0293] The refrigerant introduced into the low-pressure device (30) is combined and then introduced into the outdoor unit (100). The refrigerant introduced into the outdoor unit (100) flows through the low-pressure connecting pipe (175) into the second port of the four-way valve (140) and is then discharged through the fourth port.

[0294] The refrigerant discharged from the above four-way valve (140) flows into the gas-liquid separator (150) along the return pipe (190). The gaseous refrigerant separated by passing through the gas-liquid separator (150) can be sucked into the compressor (110) through the suction pipe (160).

[0295] This circulation of refrigerant can be repeated.

[0296] The above-mentioned eighth mode can be called a “partial cooling mode” in that a part of the first heat exchanger (210) functions as an evaporator and the second heat exchanger (220) functions as an evaporator.

[0297] Fig. 10 is a hygroscopic diagram showing a set temperature and humidity area according to the first embodiment of the present invention, and Fig. 11 is a table summarizing the set temperature and humidity area according to the first embodiment of the present invention.

[0298] The horizontal axis of Fig. 10 represents dry bulb temperature, and the vertical axis of Fig. 10 represents relative humidity. Referring to Figs. 10 and 11, according to the present invention, the temperature and humidity region can be divided into multiple regions based on the psychrometric chart.

[0299] In this embodiment, the temperature and humidity zones may include a first zone (A1), a second zone (A2), a third zone (A3), a fourth zone (A4), a fifth zone (A5), a sixth zone (A6), a seventh zone (A7), an eighth zone (A8), a ninth zone (A9), and a comfort zone (Comfort Zone, A0).

[0300] The above first region (A1) can be defined as a region where the dry bulb temperature is 14 degrees or lower. The above first region (A1) can be understood as a low-temperature region.

[0301] The above air conditioner (10) can detect the temperature and humidity of an indoor space and, when the temperature and humidity range corresponds to the first area (A1), switch to the first mode (high heating mode) and operate. Accordingly, the indoor temperature can rise, creating a comfortable indoor environment.

[0302] The second region (A2) above can be defined as a region where the dry bulb temperature is between 15 and 22 degrees and the relative humidity is 20% or higher. The second region (A2) above can be understood as a region where the temperature falls within a comfortable range.

[0303] The above air conditioner (10) can detect the temperature and humidity of an indoor space and, when the temperature and humidity range corresponds to the second range (A2), switch to the second mode (constant temperature dehumidification mode) and operate. Accordingly, the indoor humidity can be lowered, creating a comfortable indoor environment.

[0304] The third region (A3) above can be defined as a region where the dry bulb temperature is between 22 and 26 degrees and the relative humidity is 60% or higher. The third region (A3) above can be understood as a medium temperature and high humidity region.

[0305] The above air conditioner (10) can detect the temperature and humidity of an indoor space and, when the temperature and humidity range corresponds to the third area (A2), switch to the third mode (cooling and dehumidification mode) and operate. Accordingly, the indoor temperature and humidity can drop, creating a comfortable indoor environment.

[0306] The above fourth region (A4) can be defined as a region where the dry bulb temperature is 27 degrees or higher and the relative humidity is 60% or higher. The above fourth region (A4) can be understood as a high temperature and high humidity region.

[0307] The above air conditioner (10) can detect the temperature and humidity of an indoor space and, when the temperature and humidity range corresponds to the fourth area (A4), switch to the fourth mode (high cooling mode) and operate. Accordingly, the indoor temperature and humidity can drop, creating a comfortable indoor environment.

[0308] The above fifth region (A5) can be defined as a region where the dry bulb temperature is 27 degrees or higher and the relative humidity is between 20 and 60%. The above fifth region (A5) can be understood as a region where the humidity falls within a comfortable range.

[0309] The above air conditioner (10) detects the temperature and humidity of the indoor space, and when the temperature and humidity range corresponds to the fifth range (A5), it can switch to the second mode (constant temperature and dehumidification mode) and operate. Accordingly, the indoor humidity can be maintained, creating a comfortable indoor environment.

[0310] The above sixth region (A6) can be defined as a region where the dry bulb temperature is between 15 and 22 degrees and the relative humidity is 20 or less. The above sixth region (A6) can be understood as a low-temperature region.

[0311] The above air conditioner (10) detects the temperature and humidity of the indoor space, and when the temperature and humidity range corresponds to the sixth area (A6), it can be operated by switching to the sixth mode (partial heating mode). Accordingly, the indoor temperature rises, creating a comfortable indoor environment.

[0312] The above seventh region (A7) can be defined as a region where the dry bulb temperature is between 22 and 26 degrees and the relative humidity is 20% or less. The above seventh region (A7) can be understood as a high temperature and low humidity region.

[0313] The above air conditioner (10) can detect the temperature and humidity of an indoor space and, when the temperature and humidity range falls within the seventh area (A7), switch to the seventh mode (mild cooling mode) and operate. Accordingly, the indoor temperature rises, creating a comfortable indoor environment.

[0314] The above-mentioned eighth region (A8) can be defined as a region where the dry bulb temperature is 27 degrees or higher and the relative humidity is 20% or lower. The above-mentioned eighth region (A8) can be understood as a high temperature and low humidity region.

[0315] The above air conditioner (10) can detect the temperature and humidity of the indoor space, and when the temperature and humidity range corresponds to the eighth area (A8), it can be switched to the eighth mode (mild cooling mode) and operated. Accordingly, the indoor temperature can be lowered, creating a comfortable indoor environment.

[0316] Figure 12 is a flowchart showing a control method of an air conditioner according to the first embodiment of the present invention.

[0317] Referring to Fig. 12, the air conditioner (10) can be selected for an automatic dehumidification operation mode. The automatic dehumidification operation mode can be understood as a mode in which the operation mode is automatically set to create a comfortable indoor environment by detecting the temperature and humidity of the indoor space (S10).

[0318] When the automatic dehumidification operation mode is selected, the air conditioner (10) detects the temperature and humidity of the air being sucked in and determines whether the detected temperature and humidity are within a comfortable range.

[0319] Specifically, the air conditioner (10) can detect the temperature of air sucked into the second heat exchanger (220) through the first temperature sensor (201). In addition, the air conditioner (10) can detect the humidity of air sucked into the second heat exchanger (220) through the humidity sensor (203).

[0320] For example, a temperature corresponding to a comfortable range may be a temperature between 22 and 26 degrees, and a humidity corresponding to a comfortable range may be a humidity between 20 and 60%. However, this is not limited to this, and the temperature and humidity corresponding to a comfortable range may be set arbitrarily (S20, S30).

[0321] If the detected temperature and humidity are within the comfortable range, the air conditioner (10) can maintain the current operation mode (S40).

[0322] If the detected temperature and humidity do not fall within the comfortable range, the air conditioner (10) sets the operation mode.

[0323] Specifically, if the detected temperature and humidity do not fall within the comfortable range, the air conditioner (10) can determine which of the multiple temperature and humidity areas described above the detected temperature and humidity fall within, and can be operated in an operation mode corresponding to the area. That is, the air conditioner (10) can determine which of the first to eighth areas (A1 to A8) the detected temperature and humidity area falls within, and can be operated in any one of the first to eighth modes based on the determination result (S50).

[0324] The above air conditioner (10) determines whether the first discharge temperature reaches the dew point temperature.

[0325] Here, the first discharge temperature refers to the temperature of the air that has passed through the second heat exchanger (220). The first discharge temperature can be detected through the second temperature sensor (205).

[0326] Dew point temperature refers to the temperature at which water vapor in the air becomes saturated and dew forms when the temperature of the air decreases under a constant pressure. The dew point temperature can vary based on temperature and humidity (S60).

[0327] When the first discharge temperature does not reach the dew point temperature, the air conditioner (10) controls the frequency of the compressor (110), controls the opening of the third expansion device (275), and controls the flow valve (281, 285) and the three-way valve (291, 293, 295) (S70, S80, S90, S100).

[0328] If the first discharge temperature reaches the dew point temperature, the air conditioner (10) determines whether the second discharge temperature reaches the dew point temperature.

[0329] Here, the second discharge temperature refers to the temperature of the air discharged from the first indoor unit (200). The second discharge temperature can be detected through the third temperature sensor (207) (S110).

[0330] If the second discharge temperature does not reach the dew point temperature, the air conditioner (10) controls the opening degree of the first expansion device (271) (S120).

[0331] If the second discharge temperature reaches the dew point temperature, the air conditioner (10) can maintain the current operation mode. Then, the air conditioner (10) can re-enter step S20.

[0332] Fig. 13 is a cycle diagram showing the configuration of an air conditioner according to a second embodiment of the present invention, and Fig. 14 is a cycle diagram showing the configuration of a first indoor unit according to a second embodiment of the present invention.

[0333] The second embodiment of the present invention is otherwise identical to the first embodiment, but is characterized by the omission of the high-pressure pipe connecting the outdoor unit and the indoor unit, resulting in a "two-pipe connection structure." Therefore, only the distinctive features of this embodiment will be described below, and the identical parts from the first embodiment will be referenced.

[0334] Referring to FIGS. 13 and 14, an air conditioner (10) according to a second embodiment of the present invention may include a plurality of components constituting a refrigeration cycle and a refrigerant pipe connecting the plurality of components and guiding the flow of refrigerant.

[0335] The above air conditioner (10) may include an outdoor unit (100) and an indoor unit (200, 300).

[0336] The outdoor unit (100) may be placed outside a building, and the indoor units (200, 300) may be placed inside the building. The indoor units (200, 300) may include multiple indoor units. In this case, the refrigerant pipe may connect the outdoor unit (100) and each of the multiple indoor units (200, 300).

[0337] The above multiple indoor units (200, 300) may include a first indoor unit (200) and a second indoor unit (300).

[0338] The above outdoor unit (100) may include a compressor (110), an outdoor heat exchanger (120), an outdoor expansion valve (130), a four-way valve (140), and a gas-liquid separator (150).

[0339] The above air conditioner (10) may further include two pipes (30, 40) connecting the outdoor unit (100) and the indoor unit (200, 300).

[0340] The above two pipes (30, 40) may include a gas pipe (30) through which high-pressure or low-pressure gaseous refrigerant flows, and a liquid pipe (40) through which liquid refrigerant flows.

[0341] The above outdoor unit (100) and the above indoor unit (200, 300) have a “two-pipe connection structure”, and the refrigerant can circulate through the outdoor unit (100) and the indoor unit (200, 300) through two pipes (30, 40).

[0342] The above air conditioner (10) may further include a distributor (60, 70) that connects the outdoor unit (100) and the indoor unit (200, 300).

[0343] The above distributor (60, 70) may include a second distributor (60) connected to the gas pipe (30). The second distributor (60) receives refrigerant discharged from the second port of the four-way valve (140) and distributes the received refrigerant to the first indoor unit (200) or the second indoor unit (300). In addition, the second distributor (60) may guide the refrigerant discharged from the first indoor unit (200) or the second indoor unit (300) to the outdoor unit (100) after the refrigerant is combined.

[0344] The above air conditioner (10) may further include a first gas pipe connection pipe (61) connecting the second distributor (60) and the first indoor unit (200).

[0345] The above air conditioner (10) may further include a second gas pipe connection pipe (62) connecting the second distributor (60) and the second indoor unit (300).

[0346] The above distributor (60, 70) may include a third distributor (70) connected to the liquid pipe (40). The third distributor (70) receives refrigerant discharged from the outdoor heat exchanger (120) and distributes the received refrigerant to the first indoor unit (200) or the second indoor unit (300). In addition, the third distributor (70) may guide the refrigerant discharged from the first indoor unit (200) or the second indoor unit (300) to the outdoor unit (100) after the refrigerant is combined.

[0347] The above air conditioner (10) may further include a first liquid pipe connection pipe (71) connecting the third distributor (60) and the first indoor unit (200).

[0348] The above air conditioner (10) may further include a second liquid pipe connection pipe (72) connecting the third distributor (60) and the second indoor unit (300).

[0349] The above first indoor unit (200) may include a first heat exchanger (210) and a second heat exchanger (220).

[0350] The first heat exchanger (210) has a refrigerant flow path formed therein through which refrigerant flows. The first heat exchanger (210) may include a plurality of ports through which refrigerant is introduced or discharged. For example, the first heat exchanger (210) may include two ports.

[0351] The first heat exchanger (210) may include a first port (214) extending from one side of the first heat exchanger (210) and a second port (213) extending from the other side of the first heat exchanger (210).

[0352] The refrigerant may be introduced into the interior of the first heat exchanger (210) through the first port (214) and then discharged through the second port (213). Alternatively, the refrigerant may be introduced into the interior of the first heat exchanger (210) through the second port (213) and then discharged through the first port (214). During this process, the refrigerant may exchange heat with air.

[0353] The second heat exchanger (220) has a refrigerant path formed therein through which refrigerant flows. The second heat exchanger (220) can be fluidly connected to the first heat exchanger (210).

[0354] The second heat exchanger (220) may include a plurality of ports through which refrigerant is introduced or discharged. For example, the second heat exchanger (220) may include two ports.

[0355] The second heat exchanger (220) may include a first port (221) extending from one side of the second heat exchanger (220) and a second port (222) extending from the other side of the second heat exchanger (220).

[0356] The refrigerant may be introduced into the interior of the second heat exchanger (220) through the first port (221) and then discharged through the second port (222). Alternatively, the refrigerant may be introduced into the interior of the second heat exchanger (220) through the second port (222) and then discharged through the first port (221). During this process, the refrigerant may exchange heat with air.

[0357] The first indoor unit (200) may further include a gas guide pipe (241) extending from the gas pipe (30) and connected to the first heat exchanger (210) and the second heat exchanger (220), respectively.

[0358] The above gas guide pipe (241) can connect the first gas pipe connection pipe (61), the first port (214) of the first heat exchanger (210), and the first port (221) of the second heat exchanger (220), respectively.

[0359] The above first indoor unit (200) may further include a first flow valve (281) installed in the gas guide pipe (241).

[0360] The first flow valve (281) can restrict the flow of refrigerant through an opening and closing operation. For example, the first flow valve (281) can be configured as a solenoid valve.

[0361] The first indoor unit (200) may further include a first valve device (291) connected to the first port (214) of the first heat exchanger (210). The first valve device (291) may be configured as a three-way valve.

[0362] The first indoor unit (200) may further include a liquid guide pipe (251) extending from the liquid pipe (40) and connected to the first heat exchanger (210) and the second heat exchanger (220), respectively.

[0363] The above liquid guide pipe (251) can connect the first liquid pipe connection pipe (71), the second port (213) of the first heat exchanger (210), and the second port (222) of the second heat exchanger (220).

[0364] The above first indoor unit (200) may further include a third expansion device (275) installed in the liquid guide pipe (251).

[0365] The third expansion device (276) may be configured as an electronic expansion valve (EEV) whose opening can be adjusted. The degree of pressure reduction of the refrigerant can be adjusted according to the opening adjustment of the third expansion device (275).

[0366] The above first indoor unit (200) may further include a second flow valve (285) installed in the liquid guide pipe (251).

[0367] The second flow valve (285) can restrict the flow of refrigerant through an opening and closing operation. For example, the second flow valve (285) can be configured as a solenoid valve.

[0368] The above second indoor unit (300) may include an indoor heat exchanger (310).

[0369] The above indoor heat exchanger (310) may be provided to allow heat exchange between air and refrigerant. The above indoor heat exchanger (310) may function as an evaporator or a condenser depending on the operating mode of the air conditioner (10).

[0370] An indoor unit fan (315) may be installed on one side of the indoor heat exchanger (310). The indoor unit fan (315) may blow air into the indoor heat exchanger (310).

[0371] The above second indoor unit (300) may further include an indoor expansion device (320) provided on the inlet side of the indoor heat exchanger (310).

[0372] The above indoor expansion device (320) may be configured with an electronic expansion valve (EEV) whose opening can be adjusted. The degree of depressurization of the refrigerant can be adjusted according to the opening adjustment of the indoor expansion device (320).

[0373] One side of the second indoor unit (300) may be connected to the second gas pipe connection pipe (62), and the other side of the second indoor unit (300) may be connected to the second liquid pipe connection pipe (72). The second gas pipe connection pipe (62) may be connected to the indoor heat exchanger (310), and the second liquid pipe connection pipe (72) may be connected to the indoor expansion device (320).

[0374] When the above air conditioner (10) is operated in cooling mode, the valve mode of the four-way valve (140) can be switched to the second valve mode so that the outdoor heat exchanger (120) can function as a condenser and the first heat exchanger (210), the second heat exchanger (220) and the indoor heat exchanger (310) can function as evaporators.

[0375] At this time, the first valve device (291) and the third expansion device (275) can be opened. The first flow valve (281) and the second flow valve (285) can be opened.

[0376] In detail, the air conditioner (10) can control the four-way valve (140) to fluidly connect the first port and the third port of the four-way valve (140), and fluidly connect the second port and the fourth port.

[0377] Accordingly, the refrigerant compressed in the compressor (110) can be introduced into the first port of the four-way valve (140) along the discharge pipe (165) and discharged through the third port. The refrigerant discharged from the four-way valve (140) can be introduced into the outdoor heat exchanger (120) and condensed.

[0378] The refrigerant discharged from the outdoor heat exchanger (120) can be discharged from the outdoor unit (100) through the liquid pipe (40) by passing through the outdoor expansion valve (130). The refrigerant discharged from the outdoor unit (100) can be distributed and introduced into the first indoor unit (200) and the second indoor unit (300) through the third distributor (70).

[0379] The refrigerant that flows into the first indoor unit (200) through the first liquid pipe connection pipe (71) can be depressurized by flowing into the third expansion device (275) along the liquid guide pipe (251).

[0380] The refrigerant discharged from the third expansion device (275) may be introduced into the first heat exchanger (210) and the second heat exchanger (220) and evaporated.

[0381] The refrigerant discharged from the first heat exchanger (210) and the second heat exchanger (220) can be combined in the gas guide pipe (241) and then discharged from the first indoor unit (200). The refrigerant discharged from the first indoor unit (200) is introduced into the gas pipe (30) through the second distributor (60).

[0382] The refrigerant introduced into the second indoor unit (300) through the second liquid pipe connection (72) may be introduced into the indoor expansion valve (320), depressurized, and then evaporated in the indoor heat exchanger (310). The refrigerant discharged from the indoor heat exchanger (310) is introduced into the gas pipe (30) through the second distributor (60).

[0383] The refrigerant introduced into the above gas pipe (30) is combined and then introduced into the outdoor unit (100). The refrigerant introduced into the outdoor unit (100) is introduced into the second port of the four-way valve (140) and then discharged through the fourth port.

[0384] The refrigerant discharged from the above four-way valve (140) flows into the gas-liquid separator (150) along the return pipe (190). The gaseous refrigerant separated by passing through the gas-liquid separator (150) can be sucked into the compressor (110) through the suction pipe (160).

[0385] This circulation of refrigerant can be repeated.

[0386] Fig. 15 is a cycle diagram showing the configuration of an air conditioner according to a third embodiment of the present invention.

[0387] The third embodiment of the present invention is otherwise identical to the first embodiment, with the only difference being the configuration of the second indoor unit. Therefore, only the distinctive features of this embodiment will be described below, and the same parts as the first embodiment will be referenced.

[0388] Referring to FIG. 15, an air conditioner (10) according to a third embodiment of the present invention includes an outdoor unit (100), a first indoor unit (200), and a second indoor unit (300).

[0389] In this embodiment, the first indoor unit (200) and the second indoor unit (300) have the same configuration. That is, the second indoor unit (300) in this embodiment may have the same configuration as the first indoor unit (200) described in the first embodiment.

[0390] Specifically, the air conditioner (10) may further include a distributor (50, 60, 70) that connects the outdoor unit (100) and the indoor unit (200, 300).

[0391] The above distributor (50, 60, 70) may include a first distributor (50) connected to the high-pressure engine (20). Some of the refrigerant discharged from the compressor (110) flows into the first distributor (50), and the introduced refrigerant can be distributed to the first indoor unit (200) or the second indoor unit (300). In addition, the first distributor (50) may receive the refrigerant discharged from the first indoor unit (200) or the second indoor unit (300), and guide the introduced refrigerant to the outdoor unit (100).

[0392] The above air conditioner (10) may further include a first high-pressure engine connecting pipe (51) connecting the first distributor (50) and the first indoor unit (200).

[0393] The above air conditioner (10) may further include a first high-pressure engine connecting pipe (52) connecting the first distributor (50) and the second indoor unit (300).

[0394] The above distributor (50, 60, 70) may include a second distributor (60) connected to the low pressure engine (30). The second distributor (60) receives refrigerant discharged from the second port of the four-way valve (140) and distributes the received refrigerant to the first indoor unit (200) or the second indoor unit (300). In addition, the second distributor (60) may guide the refrigerant discharged from the first indoor unit (200) or the second indoor unit (300) to the outdoor unit (100) after the refrigerant is combined.

[0395] The above air conditioner (10) may further include a first low-pressure engine connection pipe (61) connecting the second distributor (60) and the first indoor unit (200).

[0396] The above air conditioner (10) may further include a second low-pressure engine connection pipe (62) connecting the second distributor (60) and the second indoor unit (300).

[0397] The above distributor (50, 60, 70) may include a third distributor (70) connected to the liquid pipe (40). The third distributor (70) receives refrigerant discharged from the outdoor heat exchanger (120) and distributes the received refrigerant to the first indoor unit (200) or the second indoor unit (300). In addition, the third distributor (70) may guide the refrigerant discharged from the first indoor unit (200) or the second indoor unit (300) to the outdoor unit (100) after the refrigerant is combined.

[0398] The above air conditioner (10) may further include a first liquid pipe connection pipe (71) connecting the third distributor (60) and the first indoor unit (200).

[0399] The above air conditioner (10) may further include a second liquid pipe connection pipe (72) connecting the third distributor (60) and the second indoor unit (300).

Claims

1. Outdoor unit including a compressor and an outdoor heat exchanger; A first indoor unit connected to the outdoor unit and including a first heat exchanger and a second heat exchanger; and It includes a second indoor unit connected to the outdoor unit and including an indoor heat exchanger, The above first indoor unit is, A high-pressure guide pipe extending from a high-pressure organ of the outdoor unit and connected to a first inlet port of the first heat exchanger; An extension pipe extending from the first outlet port of the first heat exchanger and connected to the second inlet port of the first heat exchanger; A liquid guide pipe extending from the liquid pipe of the outdoor unit and connected to the second outlet port of the first heat exchanger and the first port of the second heat exchanger; A low-pressure guide pipe extending from the low-pressure organ of the outdoor unit and connected to the second outlet port of the first heat exchanger and the second port of the second heat exchanger; and An air conditioner including a first valve device connecting the low pressure guide pipe, the liquid guide pipe, and the second outlet port to each other.

2. In paragraph 1, The above first indoor unit is, A second valve device installed in the above extension pipe; and An air conditioner including a third valve device connecting the second valve device, the liquid guide pipe, and the high-pressure guide pipe to each other.

3. In paragraph 2, An air conditioner wherein the first indoor unit further includes a first expansion device installed in the high-pressure guide pipe.

4. In paragraph 3, The above first indoor unit further includes a first connecting pipe connecting the high pressure guide pipe and the third valve device, An air conditioner in which a second expansion device is installed in the first connecting pipe.

5. In paragraph 4, The above first indoor unit further includes a second connecting pipe branched from the liquid guide pipe and connected to the second port of the second heat exchanger, An air conditioner in which a third expansion device is installed in the second connecting pipe.

6. In paragraph 5, An air conditioner wherein the first indoor unit further includes a first flow valve installed in the low-pressure guide pipe.

7. In Article 6, The first indoor unit further includes a third connecting pipe connecting the second inlet port of the first heat exchanger and the second port of the second heat exchanger. An air conditioner in which a second flow valve is installed in the third connecting pipe.

8. In paragraph 7, An air conditioner in which the first indoor unit further includes a fourth connecting pipe branched from the liquid guide pipe and connected to the third valve device.

9. In paragraph 1, An air conditioner wherein the outdoor unit includes a high-pressure connecting pipe that supplies at least a portion of the refrigerant compressed by the compressor to the high-pressure guide pipe.

10. In paragraph 9, An air conditioner wherein the outdoor unit further includes a four-way valve for sending the refrigerant compressed by the compressor to the outdoor heat exchanger or the low-pressure guide pipe.

11. In paragraph 7, When the above air conditioner is operating in the first mode, The first valve device and the second valve device are opened, and the third valve device is closed. The first expansion device and the third expansion device are opened, and the second expansion device is closed. An air conditioner in which the first flow valve and the second flow valve are closed.

12. In paragraph 7, When the above air conditioner is operated in the second mode, The first valve device and the second valve device are opened, and the third valve device is closed. The first expansion device and the third expansion device are opened, and the second expansion device is closed. An air conditioner in which the first flow valve and the second flow valve are closed.

13. In paragraph 7, When the above air conditioner is operated in the third mode, The first valve device, the second valve device and the third valve device are opened, The first expansion device and the third expansion device are opened, and the second expansion device is closed. An air conditioner in which the first flow valve and the second flow valve are opened.

14. In paragraph 7, When operating the above air conditioner in the 4th mode, The first valve device, the second valve device and the third valve device are opened, The first expansion device is closed, the second expansion device and the third expansion device are open, An air conditioner in which the first flow valve is open and the second flow valve is closed.

15. In paragraph 7, When operating the 6th mode of the above air conditioner, The first valve device is closed, the second valve device and the third valve device are open, The first expansion device and the third expansion device are opened, and the second expansion device is closed. An air conditioner in which the first flow valve and the second flow valve are closed.

16. In paragraph 7, When operating the 7th mode of the above air conditioner, The above first valve device, second valve device and third valve device are closed, The first expansion device and the second expansion device are closed, and the third expansion device is open. An air conditioner in which the first flow valve and the second flow valve are closed.

17. In paragraph 7, When operating the 8th mode of the above air conditioner, The first valve device is opened, the second valve device and the third valve device are closed, The first expansion device and the second expansion device are closed, and the third expansion device is open. An air conditioner in which the first flow valve and the second flow valve are opened.

18. In paragraph 1, A temperature sensor that detects the temperature of air passing through the first indoor unit; A humidity sensor that detects the humidity of air passing through the first indoor unit; and An air conditioner further comprising a control unit that controls the operation mode of the air conditioner based on information detected by the temperature sensor and the humidity sensor.

19. In paragraph 18, The above control unit, Calculate the dew point temperature based on the information detected by the temperature sensor and the humidity sensor, An air conditioner that determines the operation mode of the air conditioner by comparing the dew point temperature and the temperature of air passing through the second heat exchanger.

20. In paragraph 19, The above control unit, An air conditioner that determines the operation mode of the air conditioner by comparing the dew point temperature and the temperature of air passing through the first heat exchanger.

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