Air conditioner

Abstract

The present invention relates to an air conditioner. The present invention may comprise outdoor units (100, 200, 300) comprising a plurality of independent outdoor devices. The outdoor units (100, 200, 300) are connected to the plurality of outdoor devices, form an indoor duct for supplying external air or indoor air into an indoor space, and may have arranged therein a dehumidifying rotor (460) which dehumidifies the air in the indoor duct. A transfer unit is arranged between the outdoor units (100, 200, 300) and an indoor unit (400), and can transfer a main refrigerant between the outdoor units (100, 200, 300) and the indoor unit (400). Heat exchange units (700, 900) may be arranged between the transfer unit and the indoor unit (400). The heat exchange units (700, 900) may comprise a module compressor which compresses a regenerated refrigerant that flows independently of the main refrigerant, and a module heat exchanger in which each of the main refrigerant and the regenerated refrigerant circulates. Here, the module heat exchanger can carry out heat exchange between the main refrigerant and the regenerated refrigerant.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an air conditioner.BACKGROUND ART

[0002] An air conditioner is a device for controlling the temperature, humidity, cleanliness, and / or airflow distribution of air, and may include an indoor device, an outdoor device, and a controller for controlling air conditioning thereof.

[0003] Recently, an air conditioner with a dehumidifying function is also being used to maintain a constant humidity inside a building or factory. In order to keep the humidity at a predetermined level or less, an air conditioner that performs a dehumidifying function through several stages may be used.

[0004] For example, Korean Patent No. 10-1528640 (Prior Art 1) discloses a technique in which primary cooling and dehumidification are performed by using a refrigerant heat exchanger (or chilled water heat exchanger), followed by secondary dehumidification by using a dehumidifying rotor, and then tertiary cooling and dehumidification again by using the refrigerant heat exchanger (or the chilled water heat exchanger).

[0005] However, Prior Art 1 has a problem in that the operating efficiency of a cooling cycle decreases because the condensation temperature of a refrigerant varies depending on an outdoor air temperature. That is, Prior Art 1 cannot actively respond to conditions that change with the seasons (e.g., temperature or humidity conditions). In addition, Prior Art 1 has the disadvantage that, if air is excessively cooled during the tertiary cooling, an additional heat source is required for reheating, and an additional heat source is also needed to prevent the chilled water heat exchanger from freezing.

[0006] In addition, Korean Patent No. 10-1061944 (Prior Art 2) discloses an air conditioning system that can perform cooling, heating, dehumidification, and humidification functions, and is operated differently depending on the season.

[0007] However, Prior Art 2 dehumidifies indoor air by using only a desiccant rotor, which limits its ability to reduce the humidity of the indoor space below a predetermined level, and makes it unsuitable for dehumidifying large spaces. Prior Art 2 also has the problem that the condensation temperature of a refrigerant varies depending on the outdoor air temperature, resulting in low operating efficiency.

[0008] In addition, in Prior Arts 1 and 2, a regeneration heater must be operated to regenerate the dehumidifying rotor, which leads to an increase in the overall power consumption of the system due to energy required to operate the regeneration heater.

[0009] In particular, the high-temperature regeneration-type dehumidifying rotor requires regeneration at a high temperature. However, since the technologies of Prior Arts 1 and 2 have difficulty generating a high temperature through the heat exchanger, the regeneration heater must be used to create a high-temperature environment, and accordingly, this leads to increased power consumption and reduced energy efficiency.DISCLOSURETechnical Problem

[0010] The present disclosure is intended to address the problems of the prior arts as described above, and an objective of the present disclosure is to enhance dehumidification performance by including three or more stages of dehumidification and to recycle waste heat generated at each of the dehumidification stages.

[0011] Another objective of the present disclosure is to enable an air conditioner to actively respond to changing environmental conditions depending on seasons by varying operating conditions thereof.

[0012] Still another objective of the present disclosure is to reduce the use of a regeneration heater by regenerating a dehumidifying rotor by using a regeneration heat exchanger disposed in an indoor device.

[0013] Still another objective of the present disclosure is to regenerate the dehumidifying rotor in a high-temperature environment by using a regeneration refrigerant that operates independently of a main refrigerant.

[0014] Still another objective of the present disclosure is to add a heat exchange unit, which uses a regeneration refrigerant, independent of an air-conditioning unit using a main refrigerant, and to enable the heat exchange unit to utilize waste heat by exchanging heat between the main refrigerant and the regeneration refrigerant.

[0015] Still another objective of the present disclosure is to set different paths of low-pressure pipes respectively connected to a plurality of indoor heat exchangers so that the refrigerant pressure loss of a refrigerant passing through each of the paths is different.

[0016] Still another purpose of the present disclosure is to enable heat exchange between a refrigerant in a low-pressure pipe and a refrigerant in a liquid pipe through a refrigerant heat exchanger disposed between an indoor device and an outdoor device.Technical Solution

[0017] According to a feature of the present disclosure for achieving the above objectives, an air conditioner of the present disclosure may include an outdoor unit including a plurality of outdoor devices independent of each other, and an outdoor unit. The outdoor unit may be connected to the plurality of outdoor devices, and include an indoor duct that supplies external air or indoor air to an indoor space, and a dehumidifying rotor arranged therein for dehumidifying air inside the indoor duct. A transfer unit may be disposed between the outdoor unit and the indoor unit to transfer a main refrigerant between the outdoor unit and the indoor unit. In this way, according to the present disclosure, simultaneously with dehumidification by the dehumidifying rotor, a plurality of air-conditioning units may dehumidify air in several stages by using a cooling cycle. Therefore, the dehumidification performance of the air conditioner may be improved.

[0018] A heat exchange unit may be disposed between the transfer unit and the indoor unit. The heat exchange unit may include a module compressor that compresses a regeneration refrigerant flowing independently of the main refrigerant, and a module heat exchanger through which each of the main refrigerant and the regeneration refrigerant circulate. In this case, the module heat exchanger may condense the main refrigerant and evaporate the regeneration refrigerant. In this process, the module heat exchanger may enable heat exchange between the main refrigerant and the regeneration refrigerant. By enabling heat exchange between the regeneration refrigerant and the main refrigerant, the module heat exchanger may further increase heat dissipation energy of a regeneration heat exchanger.

[0019] In addition, a first regeneration heat exchanger, which forms a regeneration refrigerant cycle together with the heat exchange unit, may be disposed in the indoor unit. The first regeneration heat exchanger may condense the regeneration refrigerant compressed in the module compressor. While condensing the regeneration refrigerant, the first regeneration heat exchanger may dissipate heat to air flowing to the dehumidifying rotor. Since the first regeneration heat exchanger may regenerate the dehumidifying rotor, the usage of a regeneration heater may be reduced, thereby improving energy efficiency.

[0020] In addition, the indoor unit may include a plurality of indoor heat exchangers that exchange heat between air within the indoor duct and the main refrigerant. In the indoor unit, a first recovery heat exchanger may be disposed on a first exhaust outlet through which the air inside the indoor duct is discharged to the outside. The first recovery heat exchanger may form a main refrigerant cycle together with one of the plurality of outdoor devices and the indoor heat exchangers. In this case, the first recovery heat exchanger may exchange heat between exhaust air discharged to the outside through the first exhaust outlet and the main refrigerant. Therefore, multiple stages of dehumidification may be performed by using the plurality of indoor heat exchangers and the dehumidifying rotor, and energy efficiency may also be increased by recycling waste heat through the first recovery heat exchanger.

[0021] In addition, the module heat exchanger may be configured as a plate heat exchanger. Through the plate heat exchanger, refrigerant-to-refrigerant heat exchange between the main refrigerant and the regeneration refrigerant may be enabled.

[0022] In addition, the outdoor unit may include a first outdoor device, a second outdoor device, and a third outdoor device which are independent of each other. The main refrigerant may include a first main refrigerant compressed in the first outdoor device, a second main refrigerant compressed in the second outdoor device, and a third main refrigerant compressed in the third outdoor device. The third main refrigerant may provide additional dehumidification and cooling functions.

[0023] In addition, the indoor unit may include a first indoor heat exchanger, a second indoor heat exchanger, and the first recovery heat exchanger which constitute a first main refrigerant cycle together with the first outdoor device. The indoor unit may include a second recovery heat exchanger which constitutes a second main refrigerant cycle together with the second outdoor device, and may also include a third indoor heat exchanger and a fourth indoor heat exchanger which constitute a third main refrigerant cycle together with the third outdoor device. Since the second recovery heat exchanger operates as an evaporator, the refrigerant may effectively absorb heat from air inside the indoor unit.

[0024] In addition, the transfer unit may include a first transfer module that is disposed between the first outdoor device and the indoor unit and transfers the first main refrigerant between the first outdoor device and the indoor unit. The transfer unit may include a second transfer module that is disposed between the second outdoor device and the indoor unit and transfers the second main refrigerant between the second outdoor device and the indoor unit. The transfer unit may include a third transfer module that is disposed between the third outdoor device and the indoor unit and transfers the third main refrigerant between the third outdoor device and the indoor unit. Such a connection structure allows the plurality of heat exchangers to be operated as either condensers or evaporators.

[0025] In addition, the heat exchange unit may include a first heat exchange module that is disposed between the second transfer module and the indoor unit and operates a first regeneration refrigerant. The heat exchange unit may further include a second heat exchange module that is disposed between the third transfer module and the indoor unit and operates a second regeneration refrigerant. By operating the independent regeneration refrigerants, the first and second heat exchange modules enable each of the air-conditioning units to function as a type of cascade cycle in which high-pressure and low-pressure cycles are connected in parallel.

[0026] In addition, the first heat exchange module may include a first module compressor that compresses the first regeneration refrigerant. The first heat exchange module may further include a first module expansion valve that is connected to the first regeneration heat exchanger and expands the condensed first regeneration refrigerant. The first heat exchange module may include a first module heat exchanger that evaporates the first regeneration refrigerant and condenses the first main refrigerant.

[0027] In addition, the second heat exchange module may include a second module compressor that compresses the second regeneration refrigerant. The second heat exchange module may include a second module expansion valve that is connected to the second regeneration heat exchanger and expands the condensed second regeneration refrigerant. The second heat exchange module may include a second module heat exchanger that evaporates the second regeneration refrigerant and condenses the second main refrigerant.

[0028] In addition, the plurality of indoor heat exchangers may include the first indoor heat exchanger and the second indoor heat exchanger which are connected to the first transfer module, and the third indoor heat exchanger and the fourth indoor heat exchanger which are connected to the third transfer module. In this case, the first indoor heat exchanger and the second indoor heat exchanger may be sequentially arranged along the path of the indoor duct. The first indoor heat exchanger arranged in this manner may remove a sensible heat load that changes an indoor air temperature, and the second indoor heat exchanger may remove a latent heat load that changes indoor humidity.

[0029] In addition, the third indoor heat exchanger and the fourth indoor heat exchanger may be sequentially arranged along the path of the indoor duct, and the third indoor heat exchanger may be disposed on the opposite side of the second indoor heat exchanger with the dehumidifying rotor placed therebetween.

[0030] In addition, the first recovery heat exchanger may be connected to the first transfer module, the first indoor heat exchanger, and the second indoor heat exchanger by respective refrigerant pipes thereof.

[0031] In addition, the first transfer module may include a first refrigerant distribution valve that controls a refrigerant flow between the first outdoor device and the indoor unit, and a first refrigerant heat exchanger. In this case, the first refrigerant heat exchanger may exchange heat between the first main refrigerant flowing through a first low-pressure pipe connecting the first indoor heat exchanger and a first outdoor compressor, and the first main refrigerant flowing through a first liquid pipe connecting the second indoor heat exchanger and a first outdoor heat exchanger.

[0032] In addition, the first transfer module may transfer the first main refrigerant compressed by the first outdoor compressor to at least one of a portion of the plurality of indoor heat exchangers and the first recovery heat exchanger.

[0033] In addition, the first indoor heat exchanger may be directly connected to the first refrigerant heat exchanger, and the second indoor heat exchanger may be connected to the first refrigerant heat exchanger through the first refrigerant distribution valve.

[0034] In addition, the second transfer module may transfer the second main refrigerant compressed by a second outdoor compressor to the heat exchange unit.

[0035] In addition, the regeneration heater that regenerates the dehumidifying rotor may be arranged between the dehumidifying rotor and the first regeneration heat exchanger.

[0036] In addition, the indoor unit may include the first exhaust outlet that discharges the air inside the indoor duct to the outside and in which the first recovery heat exchanger is arranged. In addition, the indoor unit may further include a second exhaust outlet that is provided independently of the first exhaust outlet, discharges the air inside the indoor duct to the outside, and has the second recovery heat exchanger arranged therein to exchange heat between exhaust air discharged to the outside and the second main refrigerant, is arranged.

[0037] In addition, the dehumidifying rotor may be arranged between the first regeneration heat exchanger and the second recovery heat exchanger.

[0038] In addition, the second transfer module may include a second refrigerant distribution valve that controls the flow of the second main refrigerant between the second outdoor device and the first heat exchange module, and a second refrigerant heat exchanger. In this case, the second refrigerant heat exchanger may exchange heat between the second main refrigerant flowing through a second low-pressure pipe connecting the second recovery heat exchanger and the second outdoor compressor, and the second main refrigerant flowing through a second liquid pipe connecting a second outdoor heat exchanger and the heat exchange unit.

[0039] In addition, the third indoor heat exchanger may be arranged on the opposite side of the first indoor heat exchanger and the second indoor heat exchanger, with the dehumidifying rotor positioned therebetween.

[0040] In addition, the first outdoor device and the first transfer module may be connected by refrigerant pipes. In this case, the refrigerant pipes may include the first low-pressure pipe connecting a suction part of the first outdoor compressor and the first transfer module, a first high-pressure pipe connecting a discharge part of the first outdoor compressor and the first transfer module, and the first liquid pipe connecting the first outdoor heat exchanger and the first transfer module.

[0041] In addition, the first outdoor device may include a first main outdoor valve connected to each of the discharge part of the first outdoor compressor, a recovery part of a first accumulator, and the first outdoor heat exchanger. The first outdoor device may further include a first sub-outdoor valve connected to the first main outdoor valve and connected to each of the first transfer module and the recovery part of the first accumulator.

[0042] In addition, the first outdoor device, the first transfer module, the first indoor heat exchanger, the second indoor heat exchanger, and the first recovery heat exchanger may constitute a first air-conditioning unit. The second outdoor device, the second transfer module, the first heat exchange module, the first regeneration heat exchanger, and the second recovery heat exchanger may constitute a second air-conditioning unit. The third outdoor device, the third transfer module, the third indoor heat exchanger, the fourth indoor heat exchanger, the second heat exchange module, and the second regeneration heat exchanger may constitute a third air-conditioning unit.

[0043] In addition, the first indoor heat exchanger, the second indoor heat exchanger, and the first recovery heat exchanger included in the first air-conditioning unit may each be composed of a plurality of heat exchangers connected in parallel.

[0044] In addition, the outdoor unit, the indoor unit, the transfer unit, and the heat exchange unit may operate in a first air-conditioning mode, a second air-conditioning mode, or a third air-conditioning mode, which is distinguished according to a condition of an outside air temperature or outside air humidity, and the first air-conditioning mode, the second air-conditioning mode, or the third air-conditioning mode may be controlled by a main controller.Advantageous Effects

[0045] As discussed above, the air conditioner according to the present disclosure may have the following effects.

[0046] The air conditioner of the present disclosure may include the first air-conditioning unit to the third air-conditioning unit. The first air-conditioning unit may cool, heat, or dehumidify air, and the second air-conditioning unit may dehumidify air and simultaneously regenerate the dehumidifying rotor. The third air-conditioning unit may additionally cool, heat, or dehumidify air while also regenerating the dehumidifying rotor. Accordingly, in the present disclosure, simultaneously with the dehumidification by the dehumidifying rotor, the plurality of air-conditioning units may dehumidify air in several stages by using the cooling cycle. Therefore, the dehumidification performance of the air conditioner may be improved.

[0047] In addition, according to the present disclosure, the indoor device may include the plurality of indoor heat exchangers arranged in series. When air passing through the indoor device sequentially passes through these indoor heat exchangers and the dehumidifying rotor, dehumidification of five or more stages may be performed. Therefore, the air conditioner of the present disclosure may realize an ultra-low dehumidification function.

[0048] In addition, the indoor device of the air conditioner of the present disclosure may include the recovery heat exchanger, whose refrigerant may either dissipate heat to or absorb heat from exhaust air discharged to the outside. By utilizing the waste heat of the exhaust air in this way, the efficiency of a refrigeration cycle may be improved, thereby reducing the power consumption of the air conditioner and enhancing energy efficiency.

[0049] In particular, each air-conditioning unit of the present disclosure may include an independent heat pump, and the recovery heat exchanger may operate as a condenser or an evaporator. When the recovery heat exchanger operates as the condenser, a refrigerant may dissipate heat to exhaust air, and when the recovery heat exchanger operates as the evaporator, the refrigerant may absorb heat from the exhaust air. Since the heat dissipation and heat absorption of the refrigerant uses indoor air (return air), which has more favorable conditions than outside air, the air conditioner may actively respond to various seasonal and environmental conditions.

[0050] In addition, the regeneration heat exchanger arranged in the indoor device of the present disclosure may operate as a condenser and may simultaneously regenerate the dehumidifying rotor through the heat dissipation of a refrigerant. Accordingly, the regeneration efficiency of the dehumidifying rotor may be increased, thereby reducing the operation of the regeneration heater required for regenerating the dehumidifying rotor. This may improve the energy efficiency of the air conditioner.

[0051] In particular, the heat exchange unit of the present disclosure may form an independent regeneration refrigerant cycle by using a different type of refrigerant (regeneration refrigerant) within the air-conditioning unit. The regeneration heat exchanger, which forms the regeneration refrigerant cycle, may dissipate heat during the condensation of the regeneration refrigerant, thereby regenerating the dehumidifying rotor in a high-temperature environment. Accordingly, the high-temperature regeneration type dehumidifying rotor may be applied to the indoor device, and an ultra-low humidity indoor environment may be established.

[0052] In addition, the heat exchange unit may form a cascade cycle by circulating an independent regeneration refrigerant. The module heat exchanger included in the heat exchange unit may exchange heat between the regeneration refrigerant and the main refrigerant, thereby further enhancing the heat dissipation energy of the regeneration heat exchanger. As a result, the regeneration efficiency of the dehumidifying rotor may be further improved.

[0053] In addition, the second recovery heat exchanger, which constitutes the second air-conditioning unit of the present disclosure, may operate as an evaporator, and may be disposed at the outlet side of the high-temperature dehumidifying rotor. Accordingly, the refrigerant of the second recovery heat exchanger may be effectively evaporated by absorbing heat from high-temperature air discharged to the outside after passing through the dehumidifying rotor, and waste heat may be reused, thereby improving energy efficiency.

[0054] In particular, since air passing through the dehumidifying rotor is at a very high temperature, the evaporation efficiency of the second recovery heat exchanger may be significantly increased. In this case, the absorbed heat energy may be used to drive another heat exchanger (the regeneration heat exchanger).

[0055] Accordingly, the energy efficiency of the second air-conditioning unit may be further improved.

[0056] In addition, refrigerants discharged from the plurality of indoor heat exchangers provided in the indoor device of the present disclosure may be delivered to the first outdoor device through the first transfer module. In this case, low-pressure pipes respectively connected to the plurality of indoor heat exchangers may have different flow paths, which may result in different refrigerant pressure loss among the refrigerants discharged from the indoor heat exchangers. A controller may utilize temperature differences caused by the pressure loss differences to more precisely control the cooling and dehumidification functions of the air conditioner.

[0057] In addition, each of the first transfer module, the second transfer module, and the third transfer module, which are disposed between the indoor device and the outdoor device of the present disclosure, may be provided with the refrigerant heat exchanger. A refrigerant flowing through the low-pressure pipe and a refrigerant flowing through the liquid pipe may exchange heat with each other as they pass through the refrigerant heat exchanger. Accordingly, the refrigerant flowing through the liquid pipe (i) may be additionally subcooled and stabilized when the refrigerant is in a liquid state, or (ii) may be liquefied when the refrigerant is in a two-phase state. Through such cooling of the refrigerant, the operational reliability of the air conditioner may be enhanced.DESCRIPTION OF DRAWINGS

[0058] FIG. 1 is a structural diagram schematically illustrating the configuration of an air conditioner according to an embodiment of the present disclosure.

[0059] FIG. 2 is a block diagram showing the configuration of a controller and structures controlled by the controller according to an embodiment of the present disclosure.

[0060] FIG. 3 is a flowchart sequentially illustrating a process in which the air conditioner is controlled in each mode by the controller according to an embodiment of the present disclosure.

[0061] FIG. 4 is a structural diagram illustrating a refrigerant flow in a first air-conditioning mode according to an embodiment of the present disclosure.

[0062] FIG. 5 is a flowchart illustrating the refrigerant flow and air flow of a first air-conditioning unit in the first air-conditioning mode according to an embodiment of the present disclosure.

[0063] FIG. 6 is a flowchart illustrating the refrigerant flow and air flow of a second air-conditioning unit constituting in the first air-conditioning mode according to an embodiment of the present disclosure.

[0064] FIG. 7 is a flowchart illustrating the refrigerant flow and air flow of a third air-conditioning unit in the first air-conditioning mode according to an embodiment of the present disclosure.

[0065] FIG. 8 is a structural diagram showing a refrigerant flow in a second air-conditioning mode according to an embodiment of the present disclosure.

[0066] FIG. 9 is a flowchart showing the refrigerant flow and air flow of the first air-conditioning unit in the second air-conditioning mode according to an embodiment of the present disclosure.

[0067] FIG. 10 is a flowchart showing the refrigerant flow and air flow of the second air-conditioning unit in the second air-conditioning mode according to an embodiment of the present disclosure.

[0068] FIG. 11 is a flowchart showing the refrigerant flow and air flow of the third air-conditioning unit in the second air-conditioning mode according to an embodiment of the present disclosure.

[0069] FIG. 12 is a structural diagram showing a refrigerant flow in a third air-conditioning mode according to an embodiment of the present disclosure.

[0070] FIG. 13 is a flowchart showing the refrigerant flow and air flow of the first air-conditioning unit in the third air-conditioning mode according to an embodiment of the present disclosure.

[0071] FIG. 14 is a flowchart showing the refrigerant flow and air flow of the second air-conditioning unit in the third air-conditioning mode according to an embodiment of the present disclosure.

[0072] FIG. 15 is a flowchart showing the refrigerant flow and air flow of the third air-conditioning unit in the third air-conditioning mode according to an embodiment of the present disclosure.

[0073] FIG. 16 is a structural diagram showing the approximate configuration of an air conditioner according to a second embodiment of the present disclosure.

[0074] FIG. 17 is a structural diagram showing the approximate configuration of an air conditioner according to a third embodiment of the present disclosure.

[0075] FIG. 18 is a schematic diagram showing a first embodiment of a first recovery heat exchanger applied to the third embodiment of FIG. 17.

[0076] FIG. 19 is a structural diagram showing a second embodiment of the first recovery heat exchanger applied to the third embodiment of FIG. 17.

[0077] FIG. 20 is a structural diagram showing a third embodiment of the first recovery heat exchanger applied to the third embodiment of FIG. 17.MODE FOR INVENTION

[0078] Hereinafter, some embodiments of the present disclosure will be described in detail with exemplary drawings. When adding reference numerals to components in each drawing, it should be noted that identical components are given the same numerals as much as possible even if they are shown in different drawings. In addition, when explaining the embodiments of the present disclosure, if a detailed description of a related known structure or function is determined to hinder understanding of the embodiments of the present disclosure, the detailed description is omitted.

[0079] The present disclosure relates to an air conditioner, and, particularly, to an air conditioner capable of dehumidifying an indoor space. In the present disclosure, the air conditioner may intake and discharge air, and during this process, the air conditioner may control the temperature and humidity of the air. The flow of air into and out of the air conditioner may be classified as follows. First, air that is controlled inside the air conditioner and discharged to the outside of the air conditioner may be divided into (i) air supplied to the indoor space (hereinafter referred to as “supply air,” SA) and (ii) air discharged to the outdoors (hereinafter referred to as “exhaust air,” EA). Conversely, air from the outside that is drawn into the air conditioner may be classified into (i) air flowing from the outside into the air conditioner (hereinafter referred to as “outside air,” OA) and (ii) air flowing from the indoor space into the air conditioner (hereinafter referred to as “return air,” RA).

[0080] In this embodiment, the waste heat of the exhaust air EA may be recycled. More specifically, heat dissipation from a refrigerant in an indoor heat exchanger to the exhaust air EA may occur, or heat absorption from the exhaust air EA to the refrigerant in the indoor heat exchanger may take place. By utilizing the exhaust air EA discarded after controlling the temperature and humidity of the indoor space for heat dissipation or absorption of a main refrigerant, energy consumption of the air conditioner may be reduced. Hereinafter, “recovery” refers to energy recovery.

[0081] In this embodiment, the air conditioner may include independent refrigerant cycles for a main refrigerant (a first refrigerant) and a regeneration refrigerant (a second refrigerant). In this case, the main refrigerant and the regeneration refrigerant may exchange heat with each other. During this refrigerant-to-refrigerant heat exchange process, waste heat generated in a main refrigerant cycle by the main refrigerant may be absorbed into a regeneration refrigerant cycle by the regeneration refrigerant. The regeneration refrigerant cycle may use the waste heat to regenerate a dehumidifying rotor 460 in a higher temperature environment, thereby saving energy of the air conditioner. Hereinafter, “regeneration” refers to the regeneration of the dehumidifying rotor 460.

[0082] Hereinafter, this embodiment will be described focusing on heat recovery structure and the regeneration structure.

[0083] Referring to FIG. 1, the air conditioner of the present embodiment may largely include a first air-conditioning unit U1, a second air-conditioning unit U2, and a third air-conditioning unit U3. The first air-conditioning unit U1, the second air-conditioning unit U2, and the third air-conditioning unit U3 may each have independent refrigerant cycles. The first air-conditioning unit U1, the second air-conditioning unit U2, and the third air-conditioning unit U3 may share an indoor duct S that supplies outside air or indoor air to the indoor space.

[0084] The first air-conditioning unit U1, the second air-conditioning unit U2, and the third air-conditioning unit U3 may respectively have independent main refrigerants flowing therein. Hereinafter, to distinguish the independent main refrigerants, the refrigerant of the first air-conditioning unit U1 may be referred to as a first main refrigerant, the refrigerant of the second air-conditioning unit U2 as a second main refrigerant, and the refrigerant of the third air-conditioning unit U3 as a third main refrigerant.

[0085] Meanwhile, a heat exchange unit 700 and 900 independent from the air-conditioning units may have a refrigerant, which is different from the main refrigerant, flowing therein. The heat exchange unit 700 and 900 may have a regeneration refrigerant flowing therein, wherein a first regeneration refrigerant may flow in the first heat exchange module 700 constituting the heat exchange unit 700 and 900, and a second regeneration refrigerant may flow in a second heat exchange module 900 constituting the heat exchange unit 700 and 900.

[0086] In this embodiment, the first air-conditioning unit U1 may cool, heat, and dehumidify air, and may recycle waste heat of the exhaust air EA. The second air-conditioning unit U2 may recycle waste heat of the exhaust air (EA) and regenerate the dehumidifying rotor 460. In addition, the third air-conditioning unit U3 may cool and dehumidify air, and regenerate the dehumidifying rotor 460.

[0087] The first air-conditioning unit U1 may include a first outdoor device 100 and a portion of an indoor device 400. The second air-conditioning unit U2 may include a second outdoor device 200 and another portion of the indoor device 400. The third air-conditioning unit U3 may include a third outdoor device 300 and the remaining portion of the indoor device 400.

[0088] In addition, the first air-conditioning unit U1 may include a first transfer module 500, the second air-conditioning unit U2 may include a second transfer module 600, and the third air-conditioning unit U3 may include a third transfer module 800. The first transfer module 500 may transfer the first main refrigerant between the first outdoor device 100 and the indoor device 400, the second transfer module 600 may transfer the second main refrigerant between the second outdoor device 200 and the indoor device 400, and the third transfer module 800 may transfer the third main refrigerant between the third outdoor device 300 and the indoor device 400.

[0089] Below, each detailed structure constituting the first air-conditioning unit U1, the second air-conditioning unit U2, and the third air-conditioning unit U3 will be described in order. Referring to FIG. 2, a controller 1000 may control the first outdoor device 100, the second outdoor device 200, the third outdoor device 300, the indoor device 400, the first transfer module 500, the second transfer module 600, the third transfer module 800, the first heat exchange module 700, and the second heat exchange module 900. The controller 1000 may control valves connecting the first outdoor device 100, the second outdoor device 200, the third outdoor device 300, the indoor device 400, the first transfer module 500, the second transfer module 600, the third transfer module 800, the first heat exchange module 700, and the second heat exchange module 900, thereby controlling both the flow direction and the flow amount of the refrigerant.

[0090] The plurality of heat exchangers included in the first air-conditioning unit U1, the second air-conditioning unit U2 and the third air-conditioning unit U3 can operate as a condenser or as an evaporator under the control of the controller 1000. This control may be implemented differently depending on a first air-conditioning mode to a third air-conditioning mode, which will be described later. Here, the heat exchangers may include first and second outdoor heat exchangers 130 and 230, first to fourth indoor heat exchangers 421, 422, 430, and 435, first and second recovery heat exchangers 410 and 440, first and second regeneration heat exchangers 450 and 470, and first and second module heat exchangers 730 and 930.

[0091] The first transfer module 500, the second transfer module 600 and the third transfer module 800 may respectively include a first refrigerant heat exchanger 530, a second refrigerant heat exchanger 630 and a third refrigerant heat exchanger 830. The first refrigerant heat exchanger 530, the second refrigerant heat exchanger 630, and the third refrigerant heat exchanger 830 may not operate as the condenser or the evaporator, but assist in heat exchange between refrigerants flowing inside the first refrigerant heat exchanger 530 and the second refrigerant heat exchanger 630.

[0092] For example, referring to FIG. 4, a medium-temperature, high-pressure first main refrigerant condensed by a first indoor heat exchanger 421 in the first air-conditioning mode may be introduced into the first refrigerant heat exchanger 530 of the first transfer module 500. In this case, a first main refrigerant of low temperature / low pressure, which has been evaporated from the first and second indoor heat exchangers 421 and 425 may flow in the first refrigerant heat exchanger 530. Accordingly, the medium-temperature, high-pressure first main refrigerant, which has been previously condensed by the first indoor heat exchanger 421, may be converted into a liquid refrigerant by dissipating heat (heat exchange) to the low temperature, low pressure first main refrigerant when passing through the first refrigerant heat exchanger 530, and then may be introduced into the first and second indoor heat exchangers 421 and 425.

[0093] Before describing each configuration, for convenience of explanation, a refrigerant pipe will first be described. The refrigerant pipe may be composed of a total of three pipes. The three refrigerant pipes may be divided into a low-pressure pipe, a high-pressure pipe, and a liquid pipe. In this case, the low-pressure pipe, the high-pressure pipe, and the liquid pipe may respectively include a plurality of components connected to each other to constitute a single low-pressure pipe, a single high-pressure pipe, and a single liquid pipe. The low-pressure pipe may be regarded as referring to components through which a low-pressure refrigerant flows, and the high-pressure pipe may be regarded as referring to components through which a high-pressure refrigerant flows.

[0094] In this case, the low-pressure pipe and the high-pressure pipe may be configured differently depending on the operating mode of the air conditioner. For example, a component used as the high-pressure pipe when the air conditioner operates in the first air-conditioning mode may be used as the low-pressure pipe when the air conditioner operates in a second air-conditioning mode. Such a three-pipe structure allows the flow direction of a refrigerant to be variable. The specific structure of the refrigerant pipe will be described again below.

[0095] In addition, the first outdoor device 100, the second outdoor device 200, and the third outdoor device 300 may constitute one outdoor unit 100, 200, 300. The outdoor unit 100, 200, 300 may be disposed outside a building. In addition, the indoor device 400 may be regarded as an indoor unit 400 corresponding thereto. The indoor unit 400 may be disposed inside a building. The first transfer module, the second transfer module, the third transfer module 800, the first heat exchange module 700, and the second heat exchange module 900 may be disposed inside or outside the building.

[0096] Referring to FIG. 1, the first outdoor device 100 may include, within its interior, a first outdoor compressor 110, a first outdoor heat exchanger 130, a first outdoor expansion valve 135, a first main outdoor valve 150, a first sub-outdoor valve 160, and a first accumulator 120. In addition, the interior of the first outdoor device 100 may include a plurality of refrigerant pipes configured to allow the first main refrigerant to flow.

[0097] Referring to the refrigerant pipes of the first outdoor device 100, the first outdoor compressor 110 and the first main outdoor valve 150 may be connected to each other by a first compressor discharge pipe L101. The first compressor discharge pipe L101 may basically constitute a portion of a first high-pressure pipe. The first outdoor heat exchanger 130 and the first main outdoor valve 150 may be connected to each other by a first-1 outdoor heat exchange connection pipe L102.

[0098] The first outdoor device 100 may include the first main outdoor valve 150 and the first sub-outdoor valve 160. The first main outdoor valve 150 and the first sub-outdoor valve 160 may be connected to each other and may control the flow direction of the first main refrigerant. In the present embodiment, each of the first main outdoor valve 150 and the first sub-outdoor valve 160 may be configured as a four-way valve.

[0099] The first main outdoor valve 150 may selectively connect the first compressor discharge pipe L101 and the first-1 outdoor heat exchange connection pipe L102 to each other. (i) When the first compressor discharge pipe L101 and the first-1 outdoor heat exchange connection pipe L102 are connected to each other by the first main outdoor valve 150, a portion of the high-temperature and high-pressure first main refrigerant discharged from the first outdoor compressor 110 may be delivered to the first outdoor heat exchanger 130 (in the first air-conditioning mode and the third air-conditioning mode). (ii) When the first compressor discharge pipe L101 and the first-1 outdoor heat exchange connection pipe L102 are blocked from each other by the first main outdoor valve 150, all of the high-temperature, high-pressure first main refrigerant discharged from the first outdoor compressor 110 may be delivered to the second indoor heat exchanger 425, which will be described later, through the first sub-outdoor valve 160 (in the second air-conditioning mode).

[0100] The first sub-outdoor valve 160 may deliver a low-temperature, low-pressure refrigerant delivered from outside the first outdoor device 100, to the first accumulator 120. In addition, the first sub-outdoor valve 160 may be connected to the first outdoor compressor 110 by the first compressor discharge pipe L101, and may be connected to the first transfer module 500 by a first-1 outdoor device connection pipe L103. Accordingly, the first sub-outdoor valve 160 may deliver all or a portion main of the high-temperature, high-pressure first refrigerant discharged from the first outdoor compressor 110 to the first transfer module 500.

[0101] The first outdoor heat exchanger 130 may operate as a condenser or an evaporator. For example, when the air conditioner operates in the first air-conditioning mode and the third air-conditioning mode, the first outdoor heat exchanger 130 may function as the condenser, and when the air conditioner operates in the second air-conditioning mode, the first outdoor heat exchanger 130 may function as the evaporator. To this end, the first outdoor expansion valve 135 may be connected to the first outdoor heat exchanger 130 via a first-2 outdoor heat exchange connection pipe L121. In addition, the first outdoor expansion valve 135 may be connected to the first transfer module 500 via a first-2 outdoor device connection pipe L122.

[0102] Next, referring to the second outdoor device 200, the second outdoor device 200 may have a structure similar to that of the first outdoor device 100. That is, the second outdoor device 200 may include a second outdoor compressor 210, a second outdoor heat exchanger 230, a second outdoor expansion valve 235, a second main outdoor valve 250, a second sub-outdoor valve 260, and a second accumulator 220. In addition, the interior of the second outdoor device 200 may include a plurality of refrigerant pipes configured to allow the second main refrigerant to flow.

[0103] Referring to the refrigerant pipes of the second outdoor device 200, the second outdoor compressor 210 and the second main outdoor valve 250 may be connected to each other by a second compressor discharge pipe L201. The second compressor discharge pipe L201 may basically constitute a portion of a second high-pressure pipe. The second outdoor heat exchanger 230 and the second main outdoor valve 250 may be connected to each other by a second-1 outdoor heat exchange connection pipe L202.

[0104] The second outdoor device 200 may include the second main outdoor valve 250 and the second sub-outdoor valve 260. The second main outdoor valve 250 and the second sub-outdoor valve 260 may be connected to each other and may control the flow direction of the second main refrigerant. In this embodiment, each of the second main outdoor valve 250 and the second sub-outdoor valve 260 may be configured as a four-way valve.

[0105] The second main outdoor valve 250 may selectively connect the second compressor discharge pipe L201 and the second-1 outdoor heat exchange connection pipe L202 to each other. (i) When the second compressor discharge pipe L201 and the second-1 outdoor heat exchange connection pipe L202 are connected to each other by the second main outdoor valve 250, a portion of a high-temperature, high-pressure refrigerant discharged from the second outdoor compressor 210 may be delivered to the second outdoor heat exchanger 230 (in the first air-conditioning mode). (ii) When the second compressor discharge pipe L201 and the second-1 outdoor heat exchange connection pipe L202 are blocked from each other by the second main outdoor valve 250, all of the high-temperature, high-pressure refrigerant discharged from the second outdoor compressor 210 may be delivered to the first heat exchange module 700, which will be described later, through the second sub-outdoor valve 260 (in the second air-conditioning mode and the third air-conditioning mode).

[0106] The second sub-outdoor valve 260 may deliver a low-temperature, low-pressure second main refrigerant delivered from outside the second outdoor device 200 to the second accumulator 220. In addition, the second sub-outdoor valve 260 may be connected to the second outdoor compressor 210 via the second compressor discharge pipe L201, and may be connected to the second transfer module 600 via a second-1 outdoor device connection pipe L203. Accordingly, the second sub-outdoor valve 260 may deliver all or a portion of the high-temperature, high-pressure second main refrigerant discharged from the second outdoor compressor 210 to the second transfer module 600.

[0107] The second outdoor heat exchanger 230 may operate as a condenser or as an evaporator. For example, when the air conditioner operates in the first air-conditioning mode, the second outdoor heat exchanger 230 may function as the condenser, and when the air conditioner operates in the second air-conditioning mode or the third air-conditioning mode, the second outdoor heat exchanger 230 may function as the evaporator. To this end, the second outdoor expansion valve 235 may be connected to the second outdoor heat exchanger 230 via a second-2 outdoor heat exchange connection pipe L221. In addition, the second outdoor expansion valve 235 may be connected to the second transfer module 600 via outdoor device connection pipe L222.

[0108] Next, referring to the third outdoor device 300, the third outdoor device 300 may have a structure similar to that of the first outdoor device 100 and the second outdoor device 200. That is, the third outdoor device 300 may include a third outdoor compressor 310, a third outdoor heat exchanger 330, a third outdoor expansion valve 335, a third main outdoor valve 350, a third sub-outdoor valve 360, and a third accumulator 420. In addition, the interior of the third outdoor device 300 may include a plurality of refrigerant pipes configured to allow the third main refrigerant to flow.

[0109] Referring to the refrigerant pipes of the third outdoor device 300, the third outdoor compressor 310 and the third main outdoor valve 350 may be connected to each other by a third compressor discharge pipe L301. The third compressor discharge pipe L301 may basically constitute a portion of a third high-pressure pipe. The third outdoor heat exchanger 330 and the third main outdoor valve 350 may be connected to each other by a third-1 outdoor heat exchange connection pipe L302.

[0110] The third outdoor device 300 may include the third main outdoor valve 350 and the third sub-outdoor valve 360. The third main outdoor valve 350 and the third sub-outdoor valve 360 may be connected to each other and may control the flow direction of the third main refrigerant. In this embodiment, each of the third main outdoor valve 350 and the third sub-outdoor valve 360 may be configured as a four-way valve.

[0111] The third main outdoor valve 350 may selectively connect the third compressor discharge pipe L301 and the third-1 outdoor heat exchange connection pipe L302 to each other. (i) When the third compressor discharge pipe L301 and the third-1 outdoor heat exchange connection pipe L302 are connected to each other by the third main outdoor valve 350, a portion of a high-temperature, high-pressure third main refrigerant discharged from the third outdoor compressor 310 may be delivered to the third outdoor heat exchanger 330 (in the first air-conditioning mode and the third air-conditioning mode. (ii) When the third compressor discharge pipe L301 and the third-1 outdoor heat exchange connection pipe L302 are blocked from each other by the third main outdoor valve 350, all of the high-temperature, high-pressure third main refrigerant discharged from the third outdoor compressor 310 may be delivered to the second heat exchange module 900, which will be described later, through the third sub-outdoor valve 360 (in the second air-conditioning mode).

[0112] The third sub-outdoor valve 360 may deliver a low-temperature, low-pressure third main refrigerant delivered from outside the third outdoor device 300 to the third accumulator 420. In addition, the third sub-outdoor valve 360 may be connected to the third outdoor compressor 310 via the third compressor discharge pipe L301, and may be connected to the third transfer module 800 via a third-1 outdoor device connection pipe L303. Accordingly, the third sub-outdoor valve 360 may deliver all or a portion of the high-temperature, high-pressure third main refrigerant discharged from the third outdoor compressor 310 to the third transfer module 800.

[0113] The third outdoor heat exchanger 330 may operate as a condenser or an evaporator. For example, when the air conditioner operates in the first air-conditioning mode and the third air-conditioning mode, the third outdoor heat exchanger 330 may function as the condenser, and when the air conditioner operates in the second air-conditioning mode, the third outdoor heat exchanger 330 may function as the evaporator. To this end, the third outdoor expansion valve 335 may be connected to the third outdoor heat exchanger 330 via a third-2 outdoor heat exchange connection pipe L321. In addition, the third outdoor expansion valve 335 may be connected to the third transfer module 800 via a third-2 outdoor device connection pipe L322.

[0114] Next, referring to the indoor device 400, the indoor device 400 may form the indoor duct S. Outside air OA or return air RA may be introduced into the indoor duct S, and the air inside the indoor duct S may be discharged as supply air SA or exhaust air EA. That is, the indoor duct S may be considered a type of air passage formed by the indoor device 400.

[0115] The indoor duct S may be provided with a plurality of air intake openings and air exhaust openings. Referring to FIG. 1, a first outside air opening G1 and a second outside air opening G2, into which outside air OA is introduced, may be independently arranged in the indoor duct S. The outside air OA may flow into the indoor duct S through each of the first outside air opening G1 and the second outside air opening G2.

[0116] The indoor duct S may be provided with an air supply opening G3 through which air controlled within the indoor duct S is supplied to the indoor space.

[0117] Dehumidified, heated or cooled air may be supplied to the indoor space through the air supply opening G3. The air supply opening G3 may face the opposite direction of the first outside air opening G1.

[0118] A return air inlet G4 through which indoor space air (the return air RA) flows back into the indoor duct S may be arranged in the above indoor duct S. Through the return air inlet G4, the return air RA may flow into the indoor duct S and may be controlled again.

[0119] The indoor duct S may be equipped with one or more exhaust outlets. The exhaust outlet may be intended to discharge air (the exhaust air EA) discharged from the interior of the indoor duct S to the outside space. In this embodiment, the exhaust outlet may include a first exhaust outlet G5 and a second exhaust outlet G6. Alternatively, the exhaust outlet may be configured as a single outlet or as three or more outlets.

[0120] A first recovery heat exchanger 410 and a second recovery heat exchanger 440 may be respectively arranged at positions adjacent to the first exhaust outlet G5 and the second exhaust outlet G6. Refrigerants of the first recovery heat exchanger 410 and the second recovery heat exchanger 440 may dissipate heat to or absorb heat from the outside air OA discharged through the first exhaust outlet G5 and the second exhaust outlet G6, respectively.

[0121] The outside air OA may have a lower temperature than the ambient air in the external space (e.g., during summer), or a higher temperature (e.g., during winter or in-between seasons). For example, in summer, when the refrigerant dissipates heat to outside air OA that is cooler than the ambient temperature, heat dissipation efficiency may be improved. In winter, when the refrigerant absorbs heat from the outside air OA that has a temperature higher than the ambient temperature, heat absorption efficiency may be enhanced. As a result, the cooling cycle efficiency of the air conditioner may be improved through the first recovery heat exchanger 410 and the second recovery heat exchanger 440, which are located to be adjacent to the first exhaust outlet G5 and the second exhaust outlet G6, respectively. The recovery by the first recovery heat exchanger 410 and the second recovery heat exchanger 440 may refer to energy recovery.

[0122] A plurality of air conditioning fans may be disposed in the indoor duct S. The air conditioning fans are intended to facilitate an air flow within the indoor duct S. In this embodiment, the air conditioning fans may include a first air conditioning fan F1, a second air conditioning fan F2, and a third air conditioning fan F3. The first air conditioning fan F1 may be disposed inside the return air inlet G4. The second air conditioning fan F2 may be disposed inside the air supply opening G3. The third air conditioning fan F3 may be disposed inside the second exhaust outlet G6.

[0123] Inside the indoor device 400, the first indoor heat exchanger 421, the second indoor heat exchanger 425, the third indoor heat exchanger 430, the fourth indoor heat exchanger 435, the first recovery heat exchanger 410, the second recovery heat exchanger 440, the first regeneration heat exchanger 450, the second regeneration heat exchanger 470, the dehumidifying rotor 460, and a regeneration heater 465, etc. may be disposed. These components within the indoor device 400, together with the first outdoor device 100 and the second outdoor device 200, may control the outside air OA or the return air RA. Here, “control” may include heating, cooling, or dehumidifying air.

[0124] The first recovery heat exchanger 410 may operate as a condenser (in the first and third air-conditioning modes) or as an evaporator (in the second air-conditioning mode). When the first recovery heat exchanger 410 operates as the condenser, the refrigerant in the first recovery heat exchanger 410 may dissipate heat to the exhaust air EA discharged from the indoor device 400 to the outside G5. In this case, the exhaust air EA may have a lower temperature than the outside air, and thus the amount of heat dissipated by the refrigerant may be increased. Accordingly, the operating high pressure of the refrigeration cycle by the first air-conditioning unit U1 may be reduced, thereby lowering power consumption.

[0125] In addition, when the first recovery heat exchanger 410 operates as an evaporator, the refrigerant in the first recovery heat exchanger 410 may absorb heat from the exhaust air EA discharged from the indoor device 400 to the outside G5. In this case, since the exhaust air EA has a higher temperature than the outside air, the amount of absorbed heat may increase. Accordingly, the operating low pressure of the refrigeration cycle by the first air-conditioning unit U1 may rise, thereby reducing power consumption.

[0126] Consequently, the first recovery heat exchanger 410 may utilize the exhaust air EA whether the first recovery heat exchanger 410 operates as a condenser or as an evaporator, thereby serving to reduce power consumption required to operate the refrigeration cycle of the first air-conditioning unit U1.

[0127] For this purpose, the first recovery heat exchanger 410 may be disposed to be adjacent to the first exhaust outlet G5 through which the exhaust air EA is discharged. In other words, the first recovery heat exchanger 410 may be disposed inside the indoor duct S such that the surface of the first recovery heat exchanger 410 faces the first exhaust outlet G5. Referring to FIG. 1, the exhaust air EA that has passed through the first recovery heat exchanger 410 may be discharged to the external space through the first exhaust outlet G5.

[0128] A first bypass B1 may be arranged in the indoor duct S. The first bypass B1 may be arranged on the side of the first air-conditioning unit U1. The first bypass B1 may be regarded as a portion of a path formed inside the indoor duct S. The first bypass B1 may include a blower fan for an air flow.

[0129] The first bypass B1 may connect (i) a path in which the return air RA, which is introduced through the return air inlet G4, passes through the first recovery heat exchanger 410 to become the exhaust air EA and moves to the first exhaust outlet G5, with (ii) a path in which the outside air OA, which is introduced through the first outside air opening G1, moves to the first indoor heat exchanger 421 and the second indoor heat exchanger 425. Accordingly, a portion of the return air RA that flows into the return air inlet G4 may be the exhaust air EA that is discharged to the outside through the first recovery heat exchanger 410, and the remaining portion may move through the first bypass B1. The air moving through the first bypass B1 may be mixed with the outside air OA introduced through the first outside air opening G1 and flow to the first indoor heat exchanger 421 and the second indoor heat exchanger 425.

[0130] In this way, in this embodiment, all of the return air RA may not become the exhaust air EA and discharged to the first exhaust outlet G5, and a portion thereof may be reused through the first bypass B1. Taking summer as an example, the temperature of return air RA introduced from the indoor space may be lower than the temperature of outside air OA supplied from the outside. Accordingly, air moving through the first bypass B1 may be mixed with the outside air OA to lower the temperature of the air, and may increase the operating efficiency of the first air-conditioning unit U1.

[0131] Relative to the first bypass B1, the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may be arranged on the opposite side of the first recovery heat exchanger 410. The first indoor heat exchanger 421 and the second indoor heat exchanger 425 may constitute one first indoor heat exchanger unit 420. The first indoor heat exchanger unit 420 may cool, heat or dehumidify the outside air OA or the return air RA. In this embodiment, the first indoor heat exchanger unit 420 may be composed of the first indoor heat exchanger 421 and the second indoor heat exchanger 425, but one of the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may be omitted.

[0132] As such, in the present embodiment, since the first indoor heat exchanger unit 420 is composed of two heat exchangers (the first indoor heat exchanger 421 and the second indoor heat exchanger 425), various types of control may be achieved depending on load conditions or environmental conditions. For example, (i) both the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may be operated to enhance cooling and dehumidification performances (a high-load condition, the first air-conditioning mode or the third air-conditioning mode), (ii) only one of the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may be operated to implement cooling and dehumidification performances (a medium-load condition), or (iii) the first indoor heat exchanger 421 may be operated as an evaporator and the second indoor heat exchanger 425 may be operated as a condenser to implement dehumidification and heating functions (a low-load condition, the second air-conditioning mode). Accordingly, by controlling the first indoor heat exchanger unit 420 differently according to load conditions or environmental conditions, power consumption required to operate the air conditioner may be reduced.

[0133] The first indoor heat exchanger 421 and the second indoor heat exchanger 425 may be arranged in series along the direction of an air flow inside the indoor duct S, positioned adjacent to each other. In this case, the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may control air sequentially. For example, when the first indoor heat exchanger 421 and the second indoor heat exchanger 425 respectively operate as evaporators (in the first air-conditioning mode and the third air-conditioning mode), air that is primarily cooled and dehumidified while passing through the first indoor heat exchanger 421 may be secondarily cooled and dehumidified as the air passes through the second indoor heat exchanger 425. In this case, the first indoor heat exchanger 421 may remove a sensible heat load, which changes an indoor air temperature, and the second indoor heat exchanger 425 may remove a latent heat load, which changes indoor humidity.

[0134] Alternatively, when the first indoor heat exchanger 421 operates as the evaporator and the second indoor heat exchanger 425 operates as the condenser (in the second air-conditioning mode), air that is primarily cooled and dehumidified while passing through the first indoor heat exchanger 421 may be heated and have an increased temperature thereof as the air passes through the second indoor heat exchanger 425.

[0135] In this case, the first indoor heat exchanger 421 may be connected to the first recovery heat exchanger 410 through a first indoor device connection pipe L128 and a first-1 indoor heat exchange connection pipe L124. In addition, a first indoor expansion valve 423 may be disposed on the first-1 indoor heat exchange connection pipe L124. The first indoor device connection pipe L128 and the first-1 indoor heat exchange connection pipe L124 may constitute a liquid pipe. The first indoor heat exchanger 421 may be connected to the first refrigerant heat exchanger 530 of the first transfer module 500 through a first heat exchange guide pipe L117. The first heat exchange guide pipe L117 may serve as a first low-pressure pipe.

[0136] When the first indoor heat exchanger 421 operates as the evaporator (in the first air-conditioning mode, the second air-conditioning mode, and the third air-conditioning mode), the first main refrigerant condensed in the first recovery heat exchanger 410 may be delivered to the first indoor expansion valve 423 through the first indoor device connection pipe L128 and be expanded, and then may be delivered to the first indoor heat exchanger 421 and evaporated, and the evaporated first main refrigerant may be delivered to the first refrigerant heat exchanger 530 through the first heat exchange guide pipe L117.

[0137] The second indoor heat exchanger 425 may be connected to the first recovery heat exchanger 410 through the first indoor device connection pipe L128, a first indoor branch pipe L125, and the first-2 indoor heat exchange connection pipe L126. In addition, a second indoor expansion valve 427 may be disposed on the first-2 indoor heat exchange connection pipe L126. In addition, the second indoor heat exchanger 425 may be connected to the first refrigerant heat exchanger 530 of the first transfer module 500 through a first-2 heat exchange connection pipe L123, and may also be connected to the first outdoor heat exchanger 130. The second indoor heat exchanger 425 may be connected to a first refrigerant distribution valve 510 of the first transfer module 500 through a first-2 distribution connection pipe L119.

[0138] When the second indoor heat exchanger 425 operates as an evaporator (in the first air-conditioning mode and the third air-conditioning mode), the first main refrigerant condensed in the first recovery heat exchanger 410 may be delivered to the second indoor expansion valve 427 through the first indoor device connection pipe L128 and the first indoor branch pipe L125, expanded, then delivered to the second indoor heat exchanger 425 to be evaporated. The evaporated first main refrigerant may be delivered to the first refrigerant distribution valve 510 through the first-2 distribution connection pipe L119. Simultaneously, the first main refrigerant condensed in the first outdoor heat exchanger 130 may also be delivered to the second indoor heat exchanger 425 through the first-2 heat exchange connection pipe L123 and evaporated. In this case, the first-2 heat exchange connection pipe L123, the first indoor device connection pipe L128, and the first indoor branch pipe L125 may constitute a first liquid pipe, and the first-2 distribution connection pipe L119 may serve as the first low-pressure pipe.

[0139] Alternatively, when the second indoor heat exchanger 425 operates as a condenser (in the second air-conditioning mode), the high-temperature / high-pressure first main refrigerant delivered to the first outdoor compressor 110 may pass through the first transfer module 500 and be delivered to the second indoor heat exchanger 425 through the first-2 distribution connection pipe L119. In the refrigerant condensed in the second indoor heat exchanger 425, (i) a portion thereof may be delivered to the first indoor heat exchanger 421 through the first-2 indoor heat exchange connection pipe L126, the first indoor branch pipe L125, and the first-1 indoor heat exchange connection pipe L124 to be evaporated, (ii) another portion thereof may be delivered to the first recovery heat exchanger 410 through the first-2 indoor heat exchange connection pipe L126, the first indoor branch pipe L125, and the first indoor device connection pipe L128 to be evaporated, and (iii) the remaining portion thereof may be delivered to the first outdoor heat exchanger 130 through the first-2 indoor heat exchange connection pipe L126, the first-2 heat exchange connection pipe L123, the first refrigerant distribution valve 510, the first-2 outdoor device connection pipe L122, and the first-2 outdoor heat exchange connection pipe L121 to be evaporated.

[0140] In this case, (i) the first-2 indoor heat exchange connection pipe L126, the first indoor branch pipe L125, and the first-1 indoor heat exchange connection pipe L124, (ii) the first-2 indoor heat exchange connection pipe L126, the first indoor branch pipe L125, and the first indoor device connection pipe L128, (iii) the first-2 indoor heat exchange connection pipe L126, the first-2 heat exchange connection pipe L123, the first refrigerant distribution valve 510, the first-2 outdoor device connection pipe L122, and the first-2 outdoor heat exchange connection pipe L121 may respectively constitute first liquid pipes.

[0141] In this embodiment, the first indoor heat exchanger 421 may be directly connected to the first refrigerant heat exchanger 530 of the first transfer module 500, but the second indoor heat exchanger 425 may join the first refrigerant heat exchanger 530 after passing through the first refrigerant distribution valve 510 of the first transfer module 500. As such, since the flow path of the first main refrigerant differs, refrigerant pressure drop through the first indoor heat exchanger 421 may be smaller than refrigerant pressure drop through the second indoor heat exchanger 425. As a result, an evaporation temperature caused by the first indoor heat exchanger 421 and an evaporation temperature caused by the second indoor heat exchanger 425 may be controlled differently. By using this temperature difference, the controller 1000 may more precisely control the cooling and dehumidification functions of the air conditioner.

[0142] The first indoor heat exchanger 421 and the second indoor heat exchanger 425, which constitute the first indoor heat exchanger unit 420, may constitute the first air-conditioning unit U1 together with the first outdoor device 100, the first transfer module 500, and the first recovery heat exchanger 410. In addition, the plurality of indoor heat exchangers 420, 430, and 435 and the first recovery heat exchanger 410, which is disposed on the first exhaust outlet G5 of the indoor duct S, may collectively be regarded as a single first heat exchange part.

[0143] The indoor device 400 may include the second recovery heat exchanger 440 disposed therein. The second recovery heat exchanger 440 may be disposed in the indoor device 400 and may operate as an evaporator (in the first air-conditioning mode, the second air-conditioning mode, and the third air-conditioning mode0. When the second recovery heat exchanger 440 operates as the evaporator, the second main refrigerant of the second recovery heat exchanger 440 may absorb heat from exhaust air EA discharged from the indoor device 400 to the outside. In this case, since the exhaust air EA has a higher temperature than outside air, the amount of absorbed heat may increase. Accordingly, the operating low pressure of the refrigeration cycle by the second air-conditioning unit U2 may increase, thereby reducing power consumption.

[0144] As a result, when the second recovery heat exchanger 440 operates as an evaporator, the second recovery heat exchanger 440 may utilize the temperature of the exhaust air EA, thereby serving to reduce power consumption required to operate the refrigeration cycle of the second air-conditioning unit U2.

[0145] To this end, the second recovery heat exchanger 440 may be disposed to be adjacent to the second exhaust outlet G6 through which the exhaust air EA is discharged. In other words, the second recovery heat exchanger 440 may be disposed inside the indoor duct S such that the surface of the second recovery heat exchanger 440 faces the second exhaust outlet G6. As shown in FIG. 1, the exhaust air EA that has passed through the second recovery heat exchanger 440 may be discharged to an external space through the second exhaust outlet G6.

[0146] The first regeneration heat exchanger 450 may be disposed in the indoor duct S. The first regeneration heat exchanger 450 may operate as a condenser. The first regeneration heat exchanger 450, together with the first heat exchange module 700, may constitute a first regeneration refrigerant cycle through which a first regeneration refrigerant flows. That is, the first heat exchange module 700 and the first regeneration heat exchanger 450 may operate an independent first regeneration refrigerant within the second air-conditioning unit U2, thereby enabling the second air-conditioning unit U2 to implement a cascade cycle in which a high-pressure cycle and a low-pressure cycle are connected in parallel.

[0147] Specifically, the second outdoor device 200, the second recovery heat exchanger 440, and the first module heat exchanger 730 of the first heat exchange module 700 may constitute a second main refrigerant cycle. The second main refrigerant may flow in the second main refrigerant cycle. The second main refrigerant cycle may allow the second main refrigerant to flow. The second main refrigerant may be a type of refrigerant different from the first regeneration refrigerant. For example, the second main refrigerant may include an R410A refrigerant, and the first regeneration refrigerant may include an R134a refrigerant.

[0148] In this case, the first module heat exchanger 730 of the first heat exchange module 700 may operate as a condenser for the second main refrigerant and as an evaporator for the first regeneration refrigerant. The first module heat exchanger 730 may be configured as plate heat exchangers and may allow two different refrigerants to pass through independent paths to exchange heat with each other. That is, the first module heat exchanger 730 may enable heat exchange between refrigerants.

[0149] Regarding the structure of the first heat exchange module 700, the first heat exchange module 700 may be disposed between the second transfer module 600 and the indoor device 400. The first heat exchange module 700, together with the second heat exchange module 900 described below, may constitute a portion of the heat exchange unit 700 and 900. The heat exchange unit 700 and 900, like the outdoor units 100, 200, and 300, may be regarded as a type of outdoor device, and may be disposed outdoors.

[0150] The first heat exchange module 700 may include a first module compressor 710, a first module accumulator 720, the first module heat exchanger 730, and a first module expansion valve 740. The first module expansion valve 740 and the first module compressor 710 may each be connected to the first regeneration heat exchanger 450. The first module heat exchanger 730 may serve as the condenser for the second main refrigerant and, at the same time, as the evaporator for the first regeneration refrigerant. This is possible because, as described above, the first module heat exchanger 730 has the structure of a plate heat exchanger. For another example, the first module heat exchanger 730 may be a double-pipe type heat exchanger instead of the plate heat exchangers.

[0151] Meanwhile, the first regeneration heat exchanger 450 operates as the condenser, and the first regeneration refrigerant in the first regeneration heat exchanger 450 may dissipate heat to air delivered toward the dehumidifying rotor 460. The air heated by the heat dissipated from the first regeneration refrigerant of the first regeneration heat exchanger 450 may be used for regenerating the dehumidifying rotor 460, thereby improving the regeneration efficiency of the dehumidifying rotor 460. Since the first regeneration heat exchanger 450 can regenerate the dehumidifying rotor 460, power consumption required to operate the regeneration heater 465 for regenerating the dehumidifying rotor 460 may be reduced.

[0152] In particular, in this embodiment, the first regeneration refrigerant may include a refrigerant with a high discharge temperature, such as the R134a. Accordingly, the first regeneration heat exchanger 450 may generate a high temperature of 80° C. or higher during a condensation process and may regenerate the high-temperature-regeneration-type dehumidifying rotor 460. The regeneration heater 465 has very low efficiency, and thus regenerating the dehumidifying rotor 460 by using the first regeneration heat exchanger 450 may significantly improve the overall energy efficiency of the air conditioner.

[0153] The dehumidifying rotor 460 and the regeneration heater 465 may be disposed in the indoor duct S. The dehumidifying rotor 460 may dehumidify air independently of the first indoor heat exchanger 421, the second indoor heat exchanger 425, the third indoor heat exchanger 430, and the fourth indoor heat exchanger 435. The dehumidifying rotor 460 may be configured as a desiccant dehumidifier, which is commonly used. More precisely, the dehumidifying rotor 460 and the regeneration heater 465 may be regarded as a single dehumidifier. In this case, the dehumidifying rotor 460 serves as a processing part, and the regeneration heater 465 serves as a regeneration part.

[0154] The dehumidifying rotor 460 may have a ring-shaped structure. The dehumidifying rotor 460 may be arranged to surround the indoor duct S in a circular manner. Although FIG. 1 illustrates the dehumidifying rotor 460 as crossing the indoor device 400, the dehumidifying rotor 460 may be arranged in a circular manner around the interior of the indoor device 400, that is, the interior of the indoor duct S.

[0155] In this embodiment, the dehumidifying rotor 460 may be disposed between the first regeneration heat exchanger 450 and the second recovery heat exchanger 440. The first regeneration heat exchanger 450 may be used as a condenser, and the refrigerant of the first regeneration heat exchanger 450 may dissipate heat toward the dehumidifying rotor 460 to regenerate the dehumidifying rotor 460.

[0156] When the second recovery heat exchanger 440 operates as an evaporator, the refrigerant of the second recovery heat exchanger 440 may absorb heat from the very high temperature exhaust air EA heated by the dehumidifying rotor 460. Accordingly, the evaporation efficiency of the second recovery heat exchanger 440 may be increased, thereby improving the overall cooling efficiency of the second air-conditioning unit U2.

[0157] The second recovery heat exchanger 440 may be disposed between the dehumidifying rotor 460 and the second exhaust outlet G6. In this configuration, air heated through the dehumidifying rotor 460 may be the exhaust air EA that is discharged through the second exhaust outlet G6. By utilizing this exhaust air EA, the evaporation efficiency of the second recovery heat exchanger 440 may be enhanced.

[0158] Although not illustrated, a plurality of temperature / humidity sensors may be arranged in the air conditioner. For example, temperature / humidity sensors may be disposed on the return air inlet G4, the first and second outdoor air inlets (G1 and G2), the inlet side of the dehumidifying rotor 460, and the outlet side of the second indoor heat exchanger 425, respectively. The controller 1000 may control each component on the basis of information about temperature and humidity obtained through the temperature / humidity sensors.

[0159] A second bypass B2 may be arranged in the indoor duct S. The second bypass B2 may be arranged on the third air-conditioning unit U3. The second bypass B2 may be regarded as a portion of a path formed inside the indoor duct S. The second bypass B2 may include a blower fan for an air flow.

[0160] The second bypass B2 may connect (i) a path through which air passing through the first indoor heat exchanger 421, the second indoor heat exchanger 425, and the dehumidifying rotor 460 passes through the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 to become supply air SA and flows to the air supply opening G3, and (ii) a path through which outside air OA introduced through the second outside air opening G2 flows toward the second regeneration heat exchanger 470. Accordingly, a portion of the air that has passed through the dehumidifying rotor 460 may pass through the fourth indoor heat exchanger 435, become the supply air SA, and be supplied to an indoor space through the air supply opening G3, and the remaining portion thereof may flow through the second bypass B2. The air that has moved through the second bypass B2 may be mixed with the outside air OA introduced through the second outside air opening G2 and then may flow toward the second regeneration heat exchanger 470.

[0161] Accordingly, in the present embodiment, not all of the air that has passed through the dehumidifying rotor 460 may be the supply air SA to be delivered to the air supply opening G3, but a portion of the air may be reused via the second bypass B2. For example, during the summer season, the temperature of the air that has passed through the dehumidifying rotor 460 may be lower than that of the outside air OA introduced from the outside. Accordingly, the air flowing through the second bypass B2 may mix with the outside air OA, thereby lowering the temperature of the air and improving the operating efficiency of the third air-conditioning unit U3.

[0162] On the opposite side of the second regeneration heat exchanger 470 with respect to the second bypass B2, the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 may be disposed. The third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 may cool and dehumidify the air that has passed through the dehumidifying rotor 460.

[0163] The third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 may be spaced apart from the first indoor heat exchanger unit 420 to constitute a second indoor heat exchanger unit. The third indoor heat exchanger 430 and the fourth indoor heat exchanger 435, together with the third outdoor device 300, the third transfer module 800, the second heat exchange module 900, and the second regeneration heat exchanger 470, may constitute the third air-conditioning unit U3.

[0164] The third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 may operate as evaporators. While operating as the evaporators, the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 may cool and dehumidify the outside air OA or the return air RA. When the air that has been cooled and dehumidified by the first indoor heat exchanger 421 and the second indoor heat exchanger 425 is further cooled and dehumidified by the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435, the humidity of the indoor space may be significantly reduced. In addition, the dehumidifying which will be described below, may also dehumidify the outside air OA or the return air RA together with the first indoor heat exchanger 421, the second indoor heat exchanger 425, the third indoor heat exchanger 430, and the fourth indoor heat exchanger 435, thereby enhancing the dehumidification performance of the air conditioner.

[0165] The third indoor heat exchanger 430 may be connected to the third transfer module 800 through a third heat exchange transfer pipe L317. The fourth indoor heat exchanger 435 may be connected to the third transfer module 800 through a fourth heat exchange transfer pipe L324.

[0166] Specifically, the third indoor heat exchanger 430 may be connected to the third refrigerant heat exchanger 830 of the third transfer module 800 through the third heat exchange transfer pipe L317 and a third heat exchange connection pipe L316. In this case, the third heat exchange transfer pipe L317 and the third heat exchange connection pipe L316 may serve as a third low-pressure pipe. That is, when the third indoor heat exchanger 430 operates as an evaporator, the low-temperature / low-pressure third main refrigerant discharged from the third indoor heat exchanger 430 may flow through the third heat exchange transfer pipe L317 and the third heat exchange connection pipe L316 to the third refrigerant heat exchanger 830, and the third refrigerant heat exchanger 830 may guide the third main refrigerant to the third outdoor device 300.

[0167] The fourth indoor heat exchanger 435 may be connected to the third refrigerant heat exchanger 830 of the third transfer module 800 via a third-2 distribution connection pipe L319. The fourth indoor heat exchanger 435 may be connected to the second module heat exchanger 930 via the fourth heat exchange transfer pipe L324. When the fourth indoor heat exchanger 435 operates as an evaporator, the fourth heat exchange transfer pipe L324 may deliver a medium-temperature, high-pressure third main refrigerant condensed in the third outdoor heat exchanger 330 to the fourth indoor heat exchanger 435 to evaporate the third main refrigerant. The low-temperature, low-pressure third main refrigerant discharged from the fourth indoor heat exchanger 435 may flow through the third-2 distribution connection pipe L319, pass through a third refrigerant distribution valve 810, and then flow into the third refrigerant heat exchanger 830. The third main refrigerant may then pass through the third refrigerant heat exchanger 830 and may be guided to the third outdoor device 300. Accordingly, the fourth heat exchange transfer pipe L324 may constitute third liquid pipe, and the third-2 distribution connection pipe L319 may constitute the third low-pressure pipe.

[0168] In this case, the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 may serve as additional indoor heat exchangers, and the additional indoor heat exchangers may be considered to constitute one second heat exchange part, together with the second regeneration heat exchanger 470.

[0169] The second regeneration heat exchanger 470 may operate as a condenser and may, together with the second heat exchange module 900, allow the second regeneration refrigerant to flow. The second regeneration heat exchanger 470 may be connected to the second module heat exchanger 930 of the second heat exchange module 900 via a second regeneration heat exchange connection pipe 347.

[0170] The second regeneration heat exchanger 470, together with the second heat exchange module 900, may constitute a second regeneration refrigerant cycle that allows the second regeneration refrigerant to flow. That is, the second heat exchange module 900 and the second regeneration heat exchanger 470 may operate an independent second regeneration refrigerant within the third air-conditioning unit U3, so that the third air-conditioning unit U3 may function as a type of cascade cycle in which a high-pressure cycle and a low-pressure cycle are connected in parallel.

[0171] Specifically, the third outdoor device 300, the third indoor heat exchanger 430, the fourth indoor heat exchanger 435, and the second module heat exchanger 930 of the second heat exchange module 900 may constitute a third main refrigerant cycle. The third main refrigerant may flow through the third main refrigerant cycle. The third main refrigerant may be a different type of refrigerant from the second regeneration refrigerant. For example, the third main refrigerant may include the R410A refrigerant, and the second regeneration refrigerant may include the R134a refrigerant.

[0172] In this case, the second module heat exchanger 930 of the second heat exchange module 900 may operate as a condenser for the third main refrigerant and as an evaporator for the second regeneration refrigerant. The second module heat exchanger 930 may be configured as plate heat exchangers and may allow two different refrigerants to pass through independent paths to exchange heat between the two refrigerants. That is, the second module heat exchanger 930 may enable heat exchange between a refrigerant and a refrigerant.

[0173] Looking at the structure of the second heat exchange module 900, the second heat exchange module 900 may be disposed between the third transfer module 800 and the indoor device 400. The second heat exchange module 900, together with the first heat exchange module 700, may constitute a portion of the heat exchange unit 700 and 900. The heat exchange unit 700 and 900, like the outdoor units 100, 200, and 300, may be regarded as a type of outdoor device, and may be disposed outdoors.

[0174] The second heat exchange module 900 may include a second module compressor 910, a second module accumulator 920, a second module heat exchanger 930, and a second module expansion valve 940. Each of the second module expansion valve 940 and the second module compressor 910 may be connected to the second regeneration heat exchanger 470. The second module heat exchanger 930 may function as a condenser for the third main refrigerant and, at the same time, as an evaporator for the second regeneration refrigerant. As explained earlier, this is possible because the second module heat exchanger 930 has the structure of a plate heat exchanger. For another example, the second module heat exchanger 930 may be a double-pipe type heat exchanger instead of a plate heat exchanger.

[0175] Meanwhile, the second regeneration heat exchanger 470 may operate as a condenser, and the second regeneration refrigerant in the second regeneration heat exchanger 470 may dissipate heat to air flowing toward the dehumidifying rotor 460 (in a direction K3 of FIG. 1). The air heated by the heat dissipation of the second regeneration refrigerant flowing through the second regeneration heat exchanger 470 may be used to regenerate the dehumidifying rotor 460, thereby improving the regeneration efficiency of the dehumidifying rotor 460. The second regeneration heat exchanger 470 may regenerate the dehumidifying rotor 460, and thus power consumption required to operate the regeneration heater 465 for regenerating the dehumidifying rotor 460 may be reduced.

[0176] Next, with reference to FIG. 3, a control method of the air conditioner according to the present embodiment will be described. First, when control begins in $100, an operation mode may be selected in S200. Here, the operation mode may vary depending on the conditions of a location at which the air conditioner is installed. For example, the operation mode may be selected according to conditions such as the temperature, humidity, and internal volume of the installation location.

[0177] In this embodiment, the operation mode may consist of the first air-conditioning mode in S310, the second air-conditioning mode in S320, and the third air-conditioning mode in S330. The first air-conditioning mode, the second air-conditioning mode, or the third air-conditioning mode may be automatically selected under different conditions. For example, depending on the outside temperature, the first air-conditioning mode, the second air-conditioning mode, or the third air-conditioning mode may be selected. The first air-conditioning mode may be selected at 27° C. or higher (T1), the second air-conditioning mode may be selected at 15° C. or lower (T2), and the third air-conditioning mode may be selected between 15° C. and 27° C. (T3). This is just one example, and the temperature conditions may vary depending on the choice of a user or an environment. Alternatively, instead of the temperature conditions, humidity conditions may serve as criteria for selecting the operation mode.

[0178] First, when the first air-conditioning mode is selected in S310, the operations of the components constituting the first air-conditioning unit U1, the second air-conditioning unit U2, and the third air-conditioning unit U3 may be controlled in S410.

[0179] Specifically, the first outdoor compressor 110, the second outdoor compressor 210, and the third outdoor compressor 310 may be operated. In addition, the first recovery heat exchanger 410, the first regeneration heat exchanger 450, the second regeneration heat exchanger 470, the first outdoor heat exchanger 130, the second outdoor heat exchanger 230, the first module heat exchanger 730, and the second module heat exchanger 930 may each operate as condensers. The first indoor heat exchanger 421, the second indoor heat exchanger 425, the third indoor heat exchanger 430, and the fourth indoor heat exchanger 435, the second recovery heat exchanger 440, the first module heat exchanger 730, and the second module heat exchanger 930 may each operate as evaporators.

[0180] In this way, the operation of each component as either the condenser or the evaporator may be controlled by the controller 1000. The controller 1000 may control the first main outdoor valve 150, the first sub-outdoor valve 160, the second main outdoor valve 250, the second sub-outdoor valve 260, the third main outdoor valve 350, the third sub-outdoor valve 360, the first transfer module 500, the second transfer module 600, and the third transfer module 800 to control the refrigerant flow of each of the first air-conditioning unit U1, the second air-conditioning unit U2, and the third air-conditioning unit U3. In addition, when the refrigerant flow is controlled, each component may be operated as the condenser or the evaporator.

[0181] More specifically, the controller 1000 may (i) control the first main outdoor valve 150, the first sub-outdoor valve 160, the second main outdoor valve 250, the second sub-outdoor valve 260, the third main outdoor valve 350, the third sub-outdoor valve 360, the first transfer module 500, the second transfer module 600, and the third transfer module 800 to control the flow of each of the first main refrigerant, the second main refrigerant, and the third main refrigerant, and simultaneously (ii) control the first heat exchange module 700 and the second heat exchange module 900 respectively to control the flow of each of the first regeneration refrigerant and the second regeneration refrigerant.

[0182] Below, the first air-conditioning mode will be described with reference to FIGS. 4 to 7. FIGS. 4 to 7 illustrate a refrigerant flow during the first air-conditioning mode. The first air-conditioning mode may perform both dehumidification and the cooling function of air to lower an indoor temperature.

[0183] Among these, FIG. 4 illustrates a main refrigerant flow and a regeneration refrigerant flow indicated by arrows during the first air-conditioning mode. FIG. 5 illustrates a first main refrigerant flow in the first air-conditioning unit U1 in the form of a flowchart, FIG. 6 illustrates a second regeneration refrigerant flow and a first regeneration refrigerant flow in the second air-conditioning unit U2 in the form of a flowchart, and FIG. 7 illustrates a third main refrigerant flow and a second regeneration refrigerant flow in the third air-conditioning unit U3 in the form of a flowchart.

[0184] First, referring first to FIGS. 4 and 5, when looking at the flow of the first main refrigerant in the first air-conditioning unit U1 in the first air-conditioning mode, the first outdoor compressor 110 may compress the first main refrigerant and discharge the high-temperature, high-pressure refrigerant through the first compressor discharge pipe L101. A portion of the discharged high-temperature, high-pressure first main refrigerant may be delivered to the first recovery heat exchanger 410, and the remaining portion may be delivered to the first outdoor heat exchanger 130. That is, the first recovery heat exchanger 410 and the first outdoor heat exchanger 130 may each be used as a condenser.

[0185] In this case, the path through which the first main refrigerant flows to the first recovery heat exchanger 410 may be the first high-pressure pipe. Here, the first high-pressure pipe may include the first compressor discharge pipe L101, the first-1 outdoor device connection pipe L103, and a first-1 distribution connection pipe L105. In this case, the first refrigerant distribution valve 510 of the first transfer module 500 may be disposed between the first-1 outdoor device connection pipe L103 and the first-1 distribution connection pipe L105, and may connect the first-1 outdoor device connection pipe L103 and the first-1 distribution connection pipe L105 to each other.

[0186] In addition, the path through which the first main refrigerant flows to the first outdoor heat exchanger 130 may also be the first high-pressure pipe. Here, the first high-pressure pipe may include the first compressor discharge pipe L101 and the first-1 outdoor heat exchange connection pipe L102. For reference, in this case, the first main outdoor valve 150 and the first sub-outdoor valve 160 may be considered to be in an OFF state.

[0187] Here, the first recovery heat exchanger 410 may be supplied with a greater flow of the first main refrigerant than the first outdoor heat exchanger 130. For example, approximately 70% of the first main refrigerant may be supplied to the first recovery heat exchanger 410, and approximately 30% of the first main refrigerant may be supplied to the first outdoor heat exchanger 130.

[0188] The first main refrigerant condensed in the first recovery heat exchanger 410 may be in a medium-temperature, high-pressure state and may be delivered to the first indoor heat exchanger 421 and the second indoor heat exchanger 425. In this case, the path through which the first main refrigerant flows to the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may be the first liquid pipe. Specifically, the first indoor device connection pipe L128 may be the first liquid pipe through which the refrigerant flows to the first indoor heat exchanger 421, and the path composed of the first indoor device connection pipe L128 and the first indoor branch pipe L125 may be the first liquid pipe through which the refrigerant flows to the second indoor heat exchanger 425.

[0189] The first indoor expansion valve 423 may be disposed in the first-1 indoor heat exchange connection pipe L124, so that the refrigerant may flow to the first indoor heat exchanger 421, which serves as the evaporator, in an expanded state in the first indoor expansion valve 423. The second indoor expansion valve 427 may be disposed in the first-2 indoor heat exchange connection pipe L126, so that the first main refrigerant may flow into the second indoor heat exchanger 425, which serves as the evaporator, in an expanded state in the second indoor expansion valve 427.

[0190] Since the first indoor heat exchanger 421 and the second indoor heat exchanger 425 each serve as evaporators, the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may cool and dehumidify air inside the indoor duct S. Outside air OA which is primarily cooled and dehumidified while passing through the first indoor heat exchanger 421 may be secondarily cooled and dehumidified while passing through the second indoor heat exchanger 425. In FIG. 5, a direction K1 in which the outside air OA passes through the first indoor heat exchanger 421 and the second indoor heat exchanger 425 and is discharged is indicated by a thick arrow.

[0191] The first main refrigerant may be supplied at different proportions to the first indoor heat exchanger 421 and the second indoor heat exchanger 425. The first indoor heat exchanger 421, which is closer to the first recovery heat exchanger 410, may be supplied with a greater amount of the first main refrigerant than the second indoor heat exchanger 425. This is because, as previously controlled by the controller 1000, a greater amount of the first main refrigerant was supplied to the first recovery heat exchanger 410 than to the first outdoor heat exchanger 130. For example, approximately 70% of the first main refrigerant may be supplied to the first indoor heat exchanger 421, and approximately 30% of the first main refrigerant may be supplied to the second indoor heat exchanger 425.

[0192] In this case, the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may be arranged side by side along an air flow direction inside the indoor duct S. Accordingly, the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may consecutively cool and dehumidify the outside air OA. The outside air OA cooled by the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may continue to flow and may thirdly be dehumidified as the outside air OA passes through the dehumidifying rotor 460. Finally, the outside air OA may fourthly and fifthly be cooled and dehumidified by the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435, becoming the supply air SA, and the supply air SA may be supplied into the indoor space through the air supply opening G3. The third to fifth dehumidification stages will be described again below.

[0193] The low-temperature, low-pressure first main refrigerant discharged from the first indoor heat exchanger 421 may flow through the first heat exchange guide pipe L117 and enter the first transfer module 500, in which the low-temperature, low-pressure first main refrigerant may be delivered to the first refrigerant heat exchanger 530 via a first heat exchange connection pipe L116 inside the first transfer module 500. In addition, the first main refrigerant may be supplied to the first accumulator 120 through a first accumulator connection pipe L111 and a first accumulator suction pipe L113, and then may be suctioned back to the first outdoor compressor 110 through a first compressor suction pipe L115. Therefore, the first heat exchange guide pipe L117, the first heat exchange connection pipe L116, the first accumulator connection pipe L111, and the first accumulator suction pipe L113 may constitute the first low-pressure pipe.

[0194] The low-temperature, low-pressure first main refrigerant discharged from the second indoor heat exchanger 425 may flow through the first-2 distribution connection pipe L119 and enter the first transfer module 500, in which the low-temperature, low-pressure first main refrigerant may join the first refrigerant heat exchanger 530 through the first refrigerant distribution valve 510. In addition, the first main refrigerant may be supplied to the first accumulator 120 through the first accumulator connection pipe L111 and the first accumulator suction pipe L113, and then may be suctioned back to the first outdoor compressor 110 through the first compressor suction pipe L115.

[0195] In this case, the first refrigerant heat exchanger 530 may exchange heat between the low-temperature, low-pressure first main refrigerant discharged from the first indoor heat exchanger 421 and the second indoor heat exchanger 425, and the medium-temperature, high-pressure refrigerant condensed in the first outdoor heat exchanger 130. The medium-temperature, high-pressure first main refrigerant condensed in the first outdoor heat exchanger 130 may dissipate heat (exchange heat) to the low-temperature, low-pressure first main refrigerant discharged from the first indoor heat exchanger 421 and the second indoor heat exchanger 425 as the medium-temperature, high-pressure first main refrigerant passes through the first refrigerant heat exchanger 530. Accordingly, the medium-temperature, high-pressure first main refrigerant may be supplied to the first indoor heat exchanger 421 and the second indoor heat exchanger 425 while being in in a liquid refrigerant state.

[0196] Looking at the first recovery heat exchanger 410, which operates as a condenser, the first main refrigerant in the first recovery heat exchanger 410 may dissipate heat toward the exhaust air EA while operating as the condenser. That is, the first main refrigerant in the first recovery heat exchanger 410 may dissipate heat to the exhaust air EA through heat exchange with the exhaust air EA discharged via the first exhaust outlet G5. In FIG. 5, the return air RA passing through the first recovery heat exchanger 410, and the first main refrigerant in the first recovery heat exchanger 410 dissipating heat to the exhaust air EA are indicated by a bold arrow.

[0197] In this case, a portion of the air supplied to the first recovery heat exchanger 410 may be return air RA drawn from the indoor space, which has a temperature lower than the temperature of outdoor air. Accordingly, since the exhaust air EA exchanging heat with the first recovery heat exchanger 410 has a temperature lower than that of the outdoor air, heat dissipation of the first main refrigerant passing through the first recovery heat exchanger 410 may be performed more effectively. That is, by utilizing the waste heat of the exhaust air EA, the heat of the first main refrigerant of the first recovery heat exchanger 410 may be dissipated more effectively. As a result, the operating high-side pressure of the refrigeration cycle in the first air-conditioning unit U1 may be reduced, thereby improving efficiency and reducing power consumption.

[0198] For example, in an environment where the outside temperature is very high during summer, it may be difficult for the first main refrigerant in the first recovery heat exchanger 410 to dissipate heat to external air, potentially resulting in a cooling overload. However, in the present embodiment, air that exchanges heat with the first main refrigerant in the first recovery heat exchanger 410 may be return air RA supplied from the indoor space, and thus may be lower in temperature than the external air, and accordingly, heat dissipation may be smoothly performed without overload.

[0199] Meanwhile, a first heat recovery expansion valve 415 may be disposed on a first heat recovery connection pipe L127 connected to the first recovery heat exchanger 410. The controller 1000 may control the opening rate of the first heat recovery expansion valve 415 to regulate the flow rate of the first main refrigerant of a high temperature and a high pressure supplied to the first recovery heat exchanger 410. The flow rate of the high-temperature and high-pressure first main refrigerant discharged from the first outdoor compressor 110 may be fixed, and thus when the flow rate of the first main refrigerant supplied to the first recovery heat exchanger 410 is adjusted, the flow rate of the first main refrigerant supplied to the first outdoor heat exchanger 130 may also be adjusted. Through the adjustment of the refrigerant flow rate, the degree of waste heat recovery through the first recovery heat exchanger (410) may be adjusted.

[0200] For example, (i) when the temperature (the indoor temperature) of the return air RA introduced through the return air inlet G4 is lower than that of the outside air, it is more effective for the first recovery heat exchanger 410, operating as a condenser, to dissipate heat from its first main refrigerant to the return air RA than to the outside air. However, (ii) when the temperature (the indoor temperature) of the return air RA introduced through the return air inlet G4 is higher than that of the outside air, it is less efficient for the first recovery heat exchanger 410, operating as a condenser, to dissipate heat from its first main refrigerant to the return air RA than to the outside air. In this case, by adjusting the opening rate of the first heat recovery expansion valve 415, it is possible to reduce the flow rate of the first main refrigerant entering the first recovery heat exchanger 410, which operates as a condenser, and increase the flow rate of the first main refrigerant entering the first outdoor heat exchanger 130, which operates as another condenser, thereby improving the heat dissipation efficiency.

[0201] Next, referring to FIGS. 4 and 6, when looking at the flow of the second main refrigerant and the flow of the first regeneration refrigerant in the second air-conditioning unit U2 in the first air-conditioning mode, the second outdoor compressor 210 may compress the second main refrigerant and discharge the high-temperature, high-pressure second main refrigerant through the second compressor discharge pipe L201. A portion of the discharged high-temperature, high-pressure second main refrigerant may be delivered to the first module heat exchanger 730 through the second transfer module 600, and the remaining portion thereof may be delivered to the second outdoor heat exchanger 230. The first module heat exchanger 730 and the second outdoor heat exchanger 230 may each be used as a condenser.

[0202] In this case, the path through which the second main refrigerant flows to the first module heat exchanger 730 may be the second high-pressure pipe. Here, the second high-pressure pipe may include the second compressor discharge pipe L201, the second-1 outdoor device connection pipe L203, and a second-1 distribution connection pipe L205. In this case, a second refrigerant distribution valve 610 of the second transfer module 600 may be arranged between the second-1 outdoor device connection pipe L203 and the second-1 distribution connection pipe L205, and may connect the second-1 outdoor device connection pipe L203 and the second-1 distribution connection pipe L205 to each other.

[0203] In addition, the path through which the second main refrigerant flows to the second outdoor heat exchanger 230 may also be the second high-pressure pipe. Here, the second high-pressure pipe may include the second compressor discharge pipe L201 and the second-1 outdoor heat exchange connection pipe L202. For reference, in this case, the second main outdoor valve 250 and the second sub-outdoor valve 260 may be considered to be in an OFF state.

[0204] The second main refrigerants condensed respectively in the first module heat exchanger 730 and the second outdoor heat exchanger 230 may be mixed with each other and evaporated in the second recovery heat exchanger 440. The second main refrigerant in the second recovery heat exchanger 440 may absorb heat from the exhaust air EA discharged from the indoor device 400 to the outside. In this case, since the exhaust air EA has a higher temperature than the outside air, the amount of absorbed heat may increase. Accordingly, the operating low pressure of the refrigeration cycle by the second air-conditioning unit U2 may rise, thereby reducing power consumption.

[0205] As a result, the second recovery heat exchanger 440 may utilize the temperature of the exhaust air EA when operating as an evaporator, thereby functioning to reduce the power consumption required for operating the refrigeration cycle of the second air-conditioning unit U2.

[0206] To this end, the second recovery heat exchanger 440 may be disposed to be adjacent to the second exhaust outlet G6 from which the exhaust air EA is discharged. In other words, the second recovery heat exchanger 440 may be disposed inside the indoor duct S such that the surface of the second recovery heat exchanger 440 faces the second exhaust outlet G6. Referring to FIG. 4, the exhaust air EA that has passed through the second recovery heat exchanger 440 may be discharged to the outside space through the second exhaust outlet G6.

[0207] In this case, the second recovery heat exchanger 440 may be disposed between the dehumidifying rotor 460 and the second exhaust outlet G6. Air heated by the dehumidifying rotor 460 may be the exhaust air EA discharged through the second exhaust outlet G6, and by utilizing this exhaust air EA, the evaporation efficiency of the second recovery heat exchanger 440 may be further increased.

[0208] As described above, the first regeneration heat exchanger 450, together with the first heat exchange module 700, may constitute a separate first regeneration refrigerant cycle that allows the first regeneration I refrigerant to flow. Here, heat generated in the first regeneration heat exchanger 450, which operates as a condenser, may be transferred to the dehumidifying rotor 460. The air introduced through the second outside air opening G2, the air delivered via the second bypass B2, and the air that has passed through the second regeneration heat exchanger 470 may exchange heat with each other while passing through the first regeneration heat exchanger 450, causing temperatures thereof to further increase.

[0209] In addition, the heated air may be delivered to the dehumidifying rotor 460 to regenerate the dehumidifying rotor 460. Accordingly, the usage of the regeneration heater 465 for regenerating the dehumidifying rotor 460 may be reduced, and as a result, power consumption for operating the second air-conditioning unit U2 may be decreased. In FIG. 6, the air heated by the first regeneration heat exchanger 450 passing through the dehumidifying rotor 460 is indicated by a thick arrow.

[0210] Meanwhile, the first module heat exchanger 730 may be supplied with a greater flow rate of the second main refrigerant than the second outdoor heat exchanger 230. For example, approximately 70% of the second main refrigerant may be supplied to the first heat exchange module 700, and approximately 30% of the second main refrigerant may be supplied to the second outdoor heat exchanger 230.

[0211] Simultaneously, the first regeneration refrigerant may flow through the first regeneration refrigerant cycle, which is composed of the first heat exchange module 700 and the first regeneration heat exchanger 450. The first module compressor 710 may discharge a compressed high-temperature, high-pressure first regeneration refrigerant through a discharge pipe L245 of the first module compressor 710. The discharged high-temperature, high-pressure first regeneration refrigerant may be delivered to the first regeneration heat exchanger 450, and the first regeneration heat exchanger 450 may condense the first regeneration refrigerant.

[0212] During the condensation process of the first regeneration refrigerant in the first regeneration heat exchanger 450, the first regeneration refrigerant may dissipate heat and, after the heat dissipation, may be converted into a medium-temperature, high-pressure liquid refrigerant. In addition, the first regeneration refrigerant may be delivered to the first module expansion valve 740 through a first regeneration heat exchange connection pipe L247 to be expanded, and then delivered to the first module heat exchanger 730 through a first module heat exchange connection pipe L248 to be evaporated. The evaporated first regeneration refrigerant may be delivered to the first module accumulator 720 through a first module accumulator suction pipe L241.

[0213] In this case, the second main refrigerant and the first regeneration refrigerant passing through the first module heat exchanger 730 may exchange heat with each other. While condensed in the first module heat exchanger 730, the second main refrigerant may dissipate heat to the first regeneration refrigerant and be converted into liquid. Accordingly, the second main refrigerant may dissipate heat more effectively, thereby reducing the operating high pressure of the second main refrigerant cycle in the second air-conditioning unit U2, improving its efficiency and lowering its power consumption.

[0214] Conversely, as the first regeneration refrigerant evaporates in the first module heat exchanger 730, the first regeneration refrigerant may absorb heat from the second main refrigerant flowing through the first module heat exchanger 730. In this case, the amount of absorbed heat may increase due to the higher temperature of the second main refrigerant. As a result, the operating low pressure of the first regeneration refrigerant cycle constituting the second air-conditioning unit U2 may increase, thereby reducing power consumption.

[0215] In particular, by increasing the air discharge temperature of the first regeneration heat exchanger 450, which constitutes the first regeneration refrigerant cycle, to approximately 80° C. or higher, discharged air may be used as regeneration energy for the high-temperature regeneration dehumidifying rotor 460. This may reduce the usage of the less efficient regeneration heater 465, thereby further improving energy efficiency.

[0216] Air heated while passing through the second regeneration heat exchanger 470 constituting the third air-conditioning unit U3 may be delivered toward the first regeneration heat exchanger 450 in the direction K3. Referring to FIG. 6, the air flow is indicated by bold arrows. The air delivered toward the first regeneration heat exchanger 450 in the direction K3 may be further heated by the first regeneration heat exchanger 450 before being delivered to the dehumidifying rotor 460. In addition, the air used to regenerate the dehumidifying rotor 460 at a high temperature may be delivered to the second recovery heat exchanger 440. The air passing through the second recovery heat exchanger 440 may be the exhaust air EA.

[0217] Next, referring to FIGS. 4 and 7, referring to FIG. 4 and FIG. 7, when looking at the flow of the third main refrigerant and the flow of the second regeneration refrigerant in the third air-conditioning unit U3 in the first air-conditioning mode, the third outdoor compressor 310 may compress the third main refrigerant and discharge the high temperature, high pressure third main refrigerant to the third compressor discharge pipe L301. A portion of the discharged high-temperature, high-pressure third main refrigerant may be delivered to the second module heat exchanger 930 through the third transfer module 800, and the remaining portion thereof may be delivered to the third outdoor heat exchanger 330. The second module heat exchanger 930 and the third outdoor heat exchanger 330 may each be used as a condenser.

[0218] In this case, the path through which the third main refrigerant flows to the second module heat exchanger 930 may be the second high-pressure pipe. Here, the second high-pressure pipe may include the third compressor discharge pipe L301, the third-1 outdoor device connection pipe L303, and a third-1 distribution connection pipe L305. In this case, the third refrigerant distribution valve 810 of the third transfer module 800 may be disposed between the third-1 outdoor device connection pipe L303 and the third-1 distribution connection pipe L305, and may connect the third-1 outdoor device connection pipe L303 and the third-1 distribution connection pipe L305 to each other.

[0219] The third main refrigerant condensed in the second module heat exchanger 930 may be in a medium-temperature, high-pressure state and may be delivered to the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435. In this case, the third main refrigerant condensed by the third outdoor heat exchanger 330 may pass through the third refrigerant heat exchanger 830 and may be mixed with the third main refrigerant condensed in the second module heat exchanger 930. The mixed third main refrigerant may be delivered to the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435.

[0220] The low-temperature, low-pressure third main refrigerant evaporated from the third and fourth indoor heat exchangers 430 and 435 may flow through the third refrigerant heat exchanger 830. Accordingly, the medium-temperature, high-pressure third main refrigerant, previously condensed by the third outdoor heat exchanger 330, may dissipate heat (exchange heat) to the low-temperature, low-pressure third main refrigerant while passing through the third refrigerant heat exchanger 830, may be converted into a liquid refrigerant, and then may be mixed with the third main refrigerant condensed in the second module heat exchanger 930.

[0221] The path through which the third main refrigerant flows toward the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 may be the third liquid pipe. Specifically, the third-2 outdoor device connection pipe L322, a second main connection pipe L323, and the fourth heat exchange transfer pipe L324 may be the third liquid pipe through which the refrigerant flows toward the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435.

[0222] The first indoor heat exchanger 421, the second indoor heat exchanger 425, a portion of the dehumidifying rotor 460, the third indoor heat exchanger 430, and the fourth indoor heat exchanger 435 may be arranged in sequence along an air flow direction within the indoor duct S. Accordingly, the first indoor heat exchanger 421, the second indoor heat exchanger 425, the portion of the dehumidifying rotor 460, the third indoor heat exchanger 430, and the fourth indoor heat exchanger 435 may consecutively dehumidify outside air OA in a total of five stages, thereby significantly reducing the humidity of the outside air OA.

[0223] The low-temperature, low-pressure third main refrigerant discharged from the third indoor heat exchanger 430 may flow into the third transfer module 800 through the third heat exchange transfer pipe L317, and may be delivered to the third refrigerant heat exchanger 830 via the third heat exchange connection pipe L316 within the third transfer module 800. At the same time, the low-temperature, low-pressure third main refrigerant discharged from the fourth indoor heat exchanger 435 may flow into the third transfer module 800 through the third-2 distribution connection pipe L319, and may be delivered to the third refrigerant heat exchanger 830 via the third refrigerant distribution valve 810 within the third transfer module 800.

[0224] In addition, the third main refrigerant that has passed through the third refrigerant heat exchanger 830 may be supplied to the third accumulator 420 through a third accumulator connection pipe L311 and a third accumulator suction pipe L313, and then may be suctioned back to the third outdoor compressor 310 through a third compressor suction pipe L315. Accordingly, the third-2 distribution connection pipe L319, the third heat exchange connection pipe L316, the third accumulator connection pipe L311, and the third accumulator suction pipe L313 may be the third low-pressure pipe.

[0225] In this case, the third refrigerant heat exchanger 830 may exchange heat between the low-temperature, low-pressure third main refrigerant discharged from the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 and the medium-temperature, high-pressure third main refrigerant condensed in the third outdoor heat exchanger 330. While passing through the third refrigerant heat exchanger 830, the medium-temperature, high-pressure third main refrigerant condensed in the third outdoor heat exchanger330 may dissipate heat to the low-temperature, low-pressure third main refrigerant discharged from the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435. Accordingly, the medium-temperature, high-pressure third main refrigerant may be supplied to the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 while being in a liquid refrigerant state.

[0226] At the same time, the second regeneration refrigerant may flow through the second regeneration refrigerant cycle, which is composed of the second module heat exchanger 900 and the second regeneration heat exchanger 470. The second module compressor 910 may discharge a compressed high-temperature, high-pressure second regeneration refrigerant through a discharge pipe L345 of the second module compressor 910. The discharged high-temperature, high-pressure second regeneration refrigerant may be delivered to the second regeneration heat exchanger 470, and the second regeneration heat exchanger 470 may condense the second regeneration refrigerant.

[0227] During the process in which the second regeneration heat exchanger 470 condenses the second regeneration refrigerant, the second regeneration refrigerant may dissipate heat, and after the heat dissipation, the second regeneration refrigerant may be converted into a medium-temperature, high-pressure liquid refrigerant. In addition, the second regeneration refrigerant may be delivered to the second module expansion valve 940 through the second regeneration heat exchange connection pipe L347 to be expanded, and then delivered to the second module heat exchanger 930 to be evaporated. The evaporated second regeneration refrigerant may be delivered to the second module accumulator through a second module accumulator suction pipe L341.

[0228] In this case, the third main refrigerant and the second regeneration refrigerant passing through the second module heat exchanger 930 may exchange heat with each other. While condensed in the second module heat exchanger 930, the third main refrigerant may dissipate heat to the second regeneration refrigerant and be converted into liquid. Accordingly, the third main refrigerant may dissipate heat more effectively, and the operating high pressure of the third main refrigerant cycle in the third air-conditioning unit U3 may be lowered, thereby improving efficiency and reducing power consumption.

[0229] Conversely, the second regeneration refrigerant may absorb heat from the third main refrigerant flowing through the second module heat exchanger 930 as the second regeneration refrigerant evaporates in the second module heat exchanger 930. In this case, since the temperature of the third main refrigerant is high, the amount of absorbed heat may increase. Accordingly, the operating low pressure of the second regeneration refrigerant cycle, which constitutes the third air-conditioning unit U3, may increase, thereby reducing power consumption. In particular, the air discharge temperature of the second regeneration heat exchanger 470, which constitutes the second regeneration refrigerant cycle, may be raised to approximately 60° C. or higher and delivered toward the first regeneration heat exchanger 450 in the direction K3. The air thus delivered may be used as regeneration energy for the high-temperature regeneration type dehumidifying rotor 460. Accordingly, the usage of the low-efficiency regeneration heater 465 may be reduced, further improving energy efficiency.

[0230] In particular, the third main refrigerant may cool and dehumidify air while evaporating in the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435. For the evaporation in the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435, the second module heat exchanger 930 must condense the third main refrigerant while dissipating heat therefrom. The second regeneration refrigerant cycle may absorb heat energy generated during this process, thereby further increasing the air discharge temperature when the second regeneration heat exchanger 470 dissipates heat. Accordingly, the usage of a dehumidification heater 365 may further be reduced.

[0231] Looking at FIG. 7, the outside air OA drawn in from outside may be heated while passing through the second regeneration heat exchanger 470, which constitutes the third air-conditioning unit U3, and the heated air may be delivered toward the first regeneration heat exchanger 450 in direction K3. In addition, when the air that previously passed through the dehumidifying rotor 460 is delivered toward the third indoor heat exchanger 430 in a the direction K2, the air may pass through the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 in sequence. During this process, the air may undergo fourth and fifth dehumidification, resulting in a significantly lower humidity. Furthermore, the air having lowered humidity may be supplied into the indoor space through the air supply opening G3.

[0232] Next, the second air-conditioning mode will be described. FIGS. 8 to 11 illustrate the flow of a refrigerant in the second air-conditioning mode. The second air-conditioning mode may perform both dehumidification and air heating to raise the indoor temperature.

[0233] First, referring to FIG. 3, a schematic operation of the second air-conditioning mode is shown. When the second air-conditioning mode is selected in S320, the operations of components constituting the first air-conditioning unit U1, the second air-conditioning unit U2, and the third air-conditioning unit U3 may be controlled in S420. Specifically, the first outdoor compressor 110, the second outdoor compressor 210, the third outdoor compressor 310, the first module compressor 710, and the second module compressor 910 may be operated.

[0234] In addition, the first regeneration heat exchanger 450, the second regeneration heat exchanger 470, the first module heat exchanger 730, and the second module heat exchanger 930 may each be operated as a condenser. The first outdoor heat exchanger 130, the second outdoor heat exchanger 230, the third outdoor heat exchanger 330, the first indoor heat exchanger 421, the third indoor heat exchanger 430, the fourth indoor heat exchanger 435, the first recovery heat exchanger 410 and the second recovery heat exchanger 440, 350, and the first module heat exchanger 730 and the second module heat exchanger 930 may each be operated as an evaporator.

[0235] As described above, the first module heat exchanger 730 and the second module heat exchanger 930 may be configured as plate heat exchangers and thus may serve as the condenser of the second main refrigerant and the third main refrigerant and the evaporator of the first regeneration refrigerant and the second regeneration refrigerant.

[0236] FIG. 8 shows a refrigerant flow represented by arrows in the second air-conditioning mode, FIG. 9 shows a first main refrigerant flow in the first air-conditioning unit U1 in the form of a flowchart, FIG. 10 shows a second main refrigerant flow and a first regeneration refrigerant flow the second air-in conditioning unit U2 in the form of a flowchart, and FIG. 11 shows a third main refrigerant flow and a second regeneration refrigerant flow in the third air-conditioning unit U3 in the form of a flowchart.

[0237] First, with reference to FIGS. 8 and 9, when looking at the flow of the first main refrigerant in the first air-conditioning unit U1 in the second air-conditioning mode, the first outdoor compressor 110 may compress the first main refrigerant and discharge a high temperature, high pressure refrigerant through the first compressor discharge pipe L101. The discharged high-temperature, high-pressure first main refrigerant may be all transferred to the second indoor heat exchanger 425. That is, the second indoor heat exchanger 425 may be used as a condenser. In addition, in the second air-conditioning mode of the first air-conditioning unit U1, the first outdoor heat exchanger 130, the first recovery heat exchanger 410, and the first indoor heat exchanger 421 may each serve as an evaporator.

[0238] In this case, the path through which the first main refrigerant flows to the second indoor heat exchanger 425 may be the first high-pressure pipe. Here, the first high-pressure pipe may be composed of the first compressor discharge pipe L101, the first-1 outdoor device connection pipe L103, and the first-2 distribution connection pipe L119. In this case, the first refrigerant distribution valve 510 of the first transfer module 500 may be disposed between the first-1 outdoor device connection pipe L103 and the first-2 distribution connection pipe L119, and may connect the first-1 outdoor device connection pipe L103 and the first-2 distribution connection pipe L119 to each other. For reference, in this case, the first main outdoor valve 150 may be in an OFF state, while the first sub-outdoor valve 160 may be in an ON state.

[0239] The first main refrigerant, which is condensed in the second indoor heat exchanger 425, may be in a medium-temperature, high-pressure state and may then be delivered to each of the first outdoor heat exchanger 130, the first recovery heat exchanger 410, and the first indoor heat exchanger 421. In this case, the path through which the first main refrigerant flows to the first outdoor heat exchanger 130, the first recovery heat exchanger 410, and the first indoor heat exchanger 421 may be the first liquid pipe. Specifically, (i) the first-2 heat exchange connection pipe L123 and the first-2 outdoor heat exchange connection pipe L121 may be the first liquid pipe through which the first main refrigerant flows to the first outdoor heat exchanger 130, (ii) the first indoor branch pipe L125 and the first indoor device connection pipe L128 may be the first liquid pipe through which the first main refrigerant flows to the first recovery heat exchanger 410; and (iii) the first indoor branch pipe L125 and the first-1 indoor heat exchange connection pipe L124 may be the first liquid pipe through which the first main refrigerant flows to the first indoor heat exchanger 421.

[0240] (i) The first outdoor expansion valve 135 may be disposed on the first-2 outdoor heat exchange connection pipe L121, so that the first main refrigerant may flow to the first outdoor heat exchanger 130, which is an evaporator, in an expanded state in the first outdoor expansion valve 135. (ii) The first heat recovery expansion valve 415 may be disposed on the first heat recovery connection pipe L127, so that the first main refrigerant may flow to the first recovery heat exchanger 410, which is an evaporator, in an expanded state in the first recovery expansion valve. (iii) The first indoor expansion valve 423 may be disposed on the first-1 indoor heat exchange connection pipe L124, so that the first main refrigerant can flow to the first indoor heat exchanger 421, which is an evaporator, in an expanded state in the first indoor expansion valve 423.

[0241] Since the first indoor heat exchanger 421 serves as the evaporator, the first indoor heat exchanger 421 may cool and dehumidify air inside the indoor duct S. Outside air OA, which has been primarily cooled and dehumidified while passing through the first indoor heat exchanger 421, may be heated to a certain extent while passing through the second indoor heat exchanger 425. In FIG. 9, the direction K1 in which the outside air OA passes through the first indoor heat exchanger 421 and the second indoor heat exchanger 425 is expressed by a thick arrow.

[0242] Different proportions of refrigerant may be supplied to the first outdoor heat exchanger 130, the first recovery heat exchanger 410, and the first indoor heat exchanger 421. For example, the flow rate of the first main refrigerant condensed in the second indoor heat exchanger 425 may be delivered in the following order: first recovery heat exchanger 410>first indoor heat exchanger 421>first outdoor heat exchanger 130. In this embodiment, 50% or more of the first main refrigerant condensed in the second indoor heat exchanger 425 may be delivered to the first recovery heat exchanger 410.

[0243] In this case, the outside air OA, which is primarily and secondarily dehumidified by the first indoor heat exchanger unit 420, may continue to flow and may be thirdly dehumidified while passing through the dehumidifying rotor 460, and finally, the outside air OA may be fourthly and fifthly dehumidified by the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435, becoming the supply air SA, which may be supplied into the indoor space through the air supply opening G3. The structure of the third to fifth stages of dehumidification will be described again below.

[0244] The low-temperature, low-pressure first main refrigerant discharged from the first indoor heat exchanger 421 may flow through the first heat exchange guide pipe L117 into the first transfer module 500 and may then be delivered to the first refrigerant heat exchanger 530 via the first heat exchange connection pipe L116 inside the first transfer module 500. In addition, the first main refrigerant may be supplied to the first accumulator 120 through the first accumulator connection pipe L111 and the first accumulator suction pipe L113, and then may be suctioned back into the first outdoor compressor 110 through the first compressor suction pipe L115. Accordingly, the first heat exchange guide pipe L117, the first heat exchange connection pipe L116, the first accumulator connection pipe L111, and the first accumulator suction pipe L113 may constitute the first low-pressure pipe.

[0245] The low-temperature, low-pressure first main refrigerant discharged from the first recovery heat exchanger 410 may flow through the first heat recovery connection pipe L127 into the first transfer module 500 and may join the first refrigerant heat exchanger 530 via the first refrigerant distribution valve 510 inside the first transfer module 500. In addition, the first main refrigerant may be supplied to the first accumulator 120 through the first accumulator connection pipe L111 and the first accumulator suction pipe L113, and then suctioned back into the first outdoor compressor 110 through the first compressor suction pipe L115.

[0246] The low-temperature, low-pressure first main refrigerant discharged from the first outdoor heat exchanger 130 may be supplied to the first accumulator 120 through the first-1 outdoor heat exchange connection pipe L102 and the first accumulator suction pipe L113, and then suctioned back into the first outdoor compressor 110 through the first compressor suction pipe L115.

[0247] In this case, the first refrigerant heat exchanger 530 may exchange heat between the low-temperature, low-pressure first main refrigerant discharged from the first indoor heat exchanger 421 and the first recovery heat exchanger 410, and the medium-temperature, high-pressure first main refrigerant condensed in the second indoor heat exchanger 425. The medium-temperature, high-pressure first main refrigerant condensed in the second indoor heat exchanger 425 may dissipate heat to the low-temperature, low-pressure first main refrigerant discharged from the first indoor heat exchanger 421 and the first recovery heat exchanger 410 while passing through the first refrigerant heat exchanger 530. Accordingly, the medium-temperature, high-pressure first main refrigerant in a liquid state may be further subcooled and stabilized by the first refrigerant heat exchanger 530, or when the first main refrigerant discharged from the condenser is in a two-phase state, the first main refrigerant may be supplied to the first outdoor heat exchanger 130 in a liquid state after being liquefied by the first refrigerant heat exchanger 530.

[0248] Looking at the first recovery heat exchanger 410, which operates as an evaporator, the first main refrigerant in the first recovery heat exchanger 410 may absorb heat from the exhaust air EA while evaporating. That is, the first main refrigerant in the first recovery heat exchanger 410 may absorb heat from the exhaust air EA discharged through the first exhaust outlet G5 while exchanging heat with the exhaust air EA. In FIG. 9, the return air RA passing through the first recovery heat exchanger 410 and the refrigerant in the first recovery heat exchanger 410 absorbing heat from the exhaust air EA are indicated by a bold arrow.

[0249] In this case, a portion of the air supplied to the first recovery heat exchanger 410 may be return air RA which is drawn in from the indoor space and may have a higher temperature than that of the outside air. Since the air exchanging heat with the first recovery heat exchanger 410 has a higher temperature than that of the outside air, it may be more effective for the first main refrigerant in the first recovery heat exchanger 410 to absorb heat from the return air RA than from the outside air. That is, by utilizing waste heat from the exhaust air EA, the first main refrigerant in the first recovery heat exchanger 410 may absorb heat more efficiently. Accordingly, the amount of the evaporation heat by the first recovery heat exchanger 410 may increase, and the efficiency of the refrigeration cycle of the first air-conditioning unit U1 may be improved due to the increase of the operating low pressure thereof.

[0250] Next, referring to FIGS. 8 and 10, when looking at the flow of the second main refrigerant in the second air-conditioning unit U2 in the second air-conditioning mode, the second outdoor compressor 210 may compress the second main refrigerant and discharge the high temperature, high pressure second main refrigerant through the second compressor discharge pipe L201. The entire discharged high temperature, high pressure second main refrigerant may be transferred to the first module heat exchanger 730 of the first heat exchange module 700 through the second transfer module 600. The first module heat exchanger 730 may serve as the condenser of the second main refrigerant cycle.

[0251] In this case, the path through which the refrigerant flows to the first heat exchange module 700 may be the second high-pressure pipe. Here, the second high-pressure pipe may include the second compressor discharge pipe L201, the second-1 outdoor device connection pipe L203, and the second-1 distribution connection pipe L205. In this case, the second refrigerant distribution valve 610 of the second transfer module 600 may be disposed between the second-1 outdoor device connection pipe L203 and the second-1 distribution connection pipe L205, and may connect the second-1 outdoor device connection pipe L203 and the second-1 distribution connection pipe L205 to each other. For reference, in this case, the second main outdoor valve 250 and the second sub-outdoor valve 260 may be regarded to be in OFF states.

[0252] While the second main refrigerant passes through the first module heat exchanger 730, the second main refrigerant may exchange heat with the first regeneration refrigerant flowing through the first module heat exchanger 730. As previously described, the first regeneration heat exchanger 450, together with the first heat exchange module 700, may constitute a separate first regeneration refrigerant cycle, which allows the first regeneration refrigerant to flow. Here, heat generated in the first regeneration heat exchanger 450, which operates as a condenser, may be transferred to the dehumidifying rotor 460. Air introduced through the second outside air opening G2, air delivered through the second bypass B2, and air that has passed through the second regeneration heat exchanger 470 may exchange heat with each other while passing through the first regeneration heat exchanger 450, thereby further increasing temperatures thereof.

[0253] In addition, the air heated in this way may be delivered to the dehumidifying rotor 460 to regenerate the dehumidifying rotor 460. Accordingly, the usage of the regeneration heater 465 for regenerating the dehumidifying rotor 460 may be reduced, thereby reducing power consumption for operating the second air-conditioning unit U2. In FIG. 10, the flow of air that has dissipated heat in the first regeneration heat exchanger 450 and passes through the dehumidifying rotor 460 is indicated by a bold arrow.

[0254] At the same time, the first regeneration refrigerant may flow through the first regeneration refrigerant cycle, which consists of the first heat exchange module 700 and the first regeneration heat exchanger 450. The first module compressor 710 may discharge a compressed high-temperature, high-pressure first regeneration refrigerant through the discharge pipe L245 of the first module compressor 710. The discharged, high-temperature, high-pressure first regeneration refrigerant may be delivered to the first regeneration heat exchanger 450, and the first regeneration heat exchanger 450 may condense the first regeneration refrigerant.

[0255] While the first regeneration heat exchanger 450 condenses the first regeneration refrigerant, the first regeneration refrigerant may dissipate heat and then be converted into a medium-temperature, high-pressure liquid refrigerant. In addition, the first regeneration refrigerant may be delivered to the first module expansion valve 740 through the first regeneration heat exchange connection pipe L247 to be expanded, and then may be delivered to the first module heat exchanger 730 through the first module heat exchange connection pipe L248 to be evaporated. The evaporated first regeneration refrigerant may then be delivered to the first module accumulator through the first module accumulator suction pipe L241.

[0256] In this case, the second main refrigerant and the first regeneration refrigerant passing through the first module heat exchanger 730 may exchange heat with each other. The second main refrigerant may be converted into a liquid refrigerant by dissipating heat to the first regeneration refrigerant while being condensed in the first module heat exchanger 730. Accordingly, the second main refrigerant may dissipate heat more effectively, and the operating high pressure of the second main refrigerant cycle in the second air-conditioning unit U2 may be lowered, thereby improving its efficiency and reducing power consumption.

[0257] Conversely, the first regeneration refrigerant may evaporate in the first module heat exchanger 730 and absorb heat from the second main refrigerant flowing through the first module heat exchanger 730. In this case, since the temperature of the second main refrigerant is high, the amount of absorbed heat may increase. Accordingly, the operating low pressure of the first regeneration refrigerant cycle, which constitutes the second air-conditioning unit U2, may increase, thereby reducing power consumption. In particular, by raising the air discharge temperature of the first regeneration heat exchanger 450, which constitutes the first regeneration refrigerant cycle, to approximately 80° C. or higher, discharged air may be used as regeneration energy for the high-temperature regeneration type dehumidifying rotor 460. This may reduce the usage of the regeneration heater 465, which has low efficiency, thereby further improving energy efficiency.

[0258] In this case, the air heated while passing through the second regeneration heat exchanger 470, which constitutes the third air-conditioning unit U3, may be delivered toward the first regeneration heat exchanger 450 in the direction K3. Referring to FIG. 10, the air flow is indicated by bold arrows. The air delivered toward the first regeneration heat exchanger 450 in the direction K3 may be further heated by the first regeneration heat exchanger 450 and then delivered to the dehumidifying rotor 460. In addition, the air that has regenerated the dehumidifying rotor 460 at a high temperature may be delivered to the second recovery heat exchanger 440. The air passing through the second recovery heat exchanger 440 may be exhaust air EA.

[0259] Meanwhile, a portion of the second main refrigerant condensed through heat exchange while passing through the second module heat exchanger 930 may be delivered to the second recovery heat exchanger 440 to be evaporated, and the remaining portion thereof may be delivered to the second outdoor heat exchanger to be evaporated.

[0260] The medium-temperature, high-pressure second main refrigerant condensed in the first module heat exchanger 730 may be evaporated in the second recovery heat exchanger 440 and the second outdoor heat exchanger 230. In this case, the path through which a refrigerant flows to the second recovery heat exchanger 440 and the second outdoor heat exchanger 230 may be a second liquid pipe.

[0261] Specifically, a first main connection pipe L224 may be the second liquid pipe through which the second main refrigerant flows to the second recovery heat exchanger 440. In addition, a first module connection pipe L223 and the second-2 outdoor device connection pipe L222 may be the second liquid pipe through which the second main refrigerant flows to the second outdoor heat exchanger 230.

[0262] In this case, the second main refrigerant in the second recovery heat exchanger 440 may absorb heat from exhaust air EA discharged from the indoor device 400 to the outside. Since the exhaust air EA has a higher temperature than the outside air, the amount of absorbed heat may increase. Accordingly, the operating low pressure of the refrigeration cycle by the second air-conditioning unit U2 may rise, thereby reducing power consumption.

[0263] As a result, the second recovery heat exchanger 440 may utilize the temperature of the exhaust air EA when operating as an evaporator, thereby functioning to reduce power consumption required for operating the refrigeration cycle of the second air-conditioning unit U2.

[0264] The low-temperature, low-pressure second main refrigerant evaporated in the second recovery heat exchanger 440 may flow into the second transfer module 600 through a second heat exchange transfer pipe L217. In addition, the second main refrigerant that has passed through the second refrigerant heat exchanger 630 via a second heat exchange connection pipe L216 may be drawn into the second outdoor compressor 210 through the second accumulator 220. Therefore, the second heat exchange transfer pipe L217, the second heat exchange connection pipe L216, a second accumulator connection pipe L211, and a second accumulator suction pipe L213 may be a second low-pressure pipe.

[0265] Meanwhile, air passing through the second indoor heat exchanger 425 may flow toward the dehumidifying rotor 460 in the direction K1 and be dehumidified while passing through the dehumidifying rotor 460. The air thus dehumidified may be delivered toward the third indoor heat exchanger 430 in the direction K2. In FIGS. 8 and 10, the appearance of air passing through the dehumidifying rotor 460 is indicated by a bold arrow.

[0266] In this case, a portion of the dehumidifying rotor 460 may be arranged along the direction of an air flow inside the indoor duct S. Accordingly, the dehumidifying rotor 460 dehumidifies the outside air OA that has previously passed through the first indoor heat exchanger 421 and the second indoor heat exchanger 425 again, so that continuous dehumidification may be performed three times in total, thereby reducing the humidity of the outside air OA to a very low level.

[0267] Next, referring to FIGS. 8 and 11, when looking at the flow of the third main refrigerant in the third air-conditioning unit U3 in the second air-conditioning mode, the third outdoor compressor 310 may compress the third main refrigerant and discharge the high temperature, high pressure third main refrigerant through the third compressor discharge pipe L301. All of the discharged high temperature, high pressure third main refrigerant may be delivered to the second module heat exchanger 930 through the third transfer module 800, and the second module heat exchanger 930 may be used as a condenser.

[0268] In this case, the path through which the third main refrigerant flows to the second module heat exchanger 930 may be the second high-pressure pipe. Here, the second high-pressure pipe may include the third compressor discharge pipe L301, the third-1 outdoor device connection pipe L303, and the third-1 distribution connection pipe L305. In this case, the third refrigerant distribution valve 810 of the third transfer module 800 may be disposed between the third-1 outdoor device connection pipe L303 and the third-1 distribution connection pipe L305, and may connect the third-1 outdoor device connection pipe L303 and the third-1 distribution connection pipe L305 to each other.

[0269] The third main refrigerant condensed in the second module heat exchanger 930 may be in a medium temperature, high pressure state and may be delivered to the third outdoor heat exchanger 330, the third indoor heat exchanger 430, and the fourth indoor heat exchanger 435.

[0270] In this case, a low temperature, low pressure third main refrigerant that has been evaporated in the third and fourth indoor heat exchangers 430 and 435 may flow through the third refrigerant heat exchanger 830. Accordingly, the medium temperature, high pressure third main refrigerant that has been condensed by the second module heat exchanger 930 may be converted into a liquid refrigerant by dissipating heat (heat exchange) to the low temperature, low pressure third main refrigerant when passing through the third refrigerant heat exchanger 830, and then may be delivered to the third outdoor heat exchanger 330.

[0271] The path of the third main refrigerant flowing to the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435, and the path of the third main refrigerant flowing to the third outdoor heat exchanger 330 may be a third liquid pipe. Specifically, the fourth heat exchange transfer pipe L324 may be the third liquid pipe through which a refrigerant flows to the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435. In addition, the second main connection pipe L323 and the third-2 outdoor device connection pipe L322 may serve as the third liquid pipe through which a refrigerant flows to the third indoor heat exchanger 430.

[0272] In this embodiment, the first indoor heat exchanger 421, the second indoor heat exchanger 425, a portion of the dehumidifying rotor 460, the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 may be arranged sequentially along the direction of an air flow inside the indoor duct S. Accordingly, the first indoor heat exchanger 421, the second indoor heat exchanger 425, the portion of the dehumidifying rotor 460, the third indoor heat exchanger 430, and the fourth indoor heat exchanger 435 may significantly reduce the humidity of outside air OA by continuously dehumidifying the outside air OA a total of five times.

[0273] The low temperature, low pressure third main refrigerant discharged from the third indoor heat exchanger 430 may be introduced into the third transfer module 800 through the third heat exchange transfer pipe L317, and may be delivered to the third refrigerant heat exchanger 830 through the third heat exchange connection pipe L316 inside the third transfer module 800. At the same time, the low temperature, low pressure third main refrigerant discharged from the fourth indoor heat exchanger 435 may be introduced into the third transfer module 800 through the third-2 distribution connection pipe L319 and delivered to the third refrigerant heat exchanger 830 through the third refrigerant distribution valve 810 inside the third transfer module 800.

[0274] In addition, the third main refrigerant that has passed through the third refrigerant heat exchanger 830 may be supplied to the third accumulator 420 through the third accumulator connection pipe L311 and the third accumulator suction pipe L313, and then suctioned back into the third outdoor compressor 310 through the third compressor suction pipe L315. Therefore, the third-2 distribution connection pipe L319, the third heat exchange connection pipe L316, the third accumulator connection pipe L311, and the third accumulator suction pipe L313 may be a third low-pressure pipe. In addition, the third-2 outdoor heat exchange connection pipe L321 and the third-1 outdoor heat exchange connection pipe L302 passing through the third outdoor heat exchanger 330 may also be the third low-pressure pipe.

[0275] In this case, the third refrigerant heat exchanger 830 may exchange heat between the low temperature, low pressure third main refrigerant discharged from the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 and the medium temperature, high pressure liquid third main refrigerant condensed in the second module heat exchanger 930. The medium temperature, high pressure third main refrigerant condensed in the second module heat exchanger 930 may dissipate heat to the low temperature, low pressure refrigerant discharged from the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 while passing through the medium temperature, high pressure third refrigerant heat exchanger 830. Accordingly, the third main refrigerant may be supplied to the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 while being in a liquid refrigerant state.

[0276] At the same time, the second regeneration refrigerant may flow in the second regeneration refrigerant cycle composed of the second heat exchange module 900 and the second regeneration heat exchanger 470. The second module compressor 910 may discharge the compressed high temperature, high pressure second regeneration refrigerant through the discharge pipe L345 of the second module compressor 910. The discharged high temperature, high pressure second regeneration refrigerant may be delivered to the second regeneration heat exchanger 470, and the second regeneration heat exchanger 470 may condense the second regeneration refrigerant.

[0277] During the process in which the second regeneration heat exchanger 470 condenses the second regeneration refrigerant, the second regeneration refrigerant may dissipate heat, and after the heat dissipation, the second regeneration refrigerant may be converted into a medium-temperature, high-pressure liquid refrigerant. In addition, the second regeneration refrigerant may be delivered to the second module expansion valve 940 through the second regeneration heat exchange connection pipe L347 to be expanded, and then delivered to the second module heat exchanger 930 to be evaporated. The evaporated second regeneration refrigerant may be delivered to the second module accumulator through the second module accumulator suction pipe L341.

[0278] In this case, the third main refrigerant and the second regeneration refrigerant passing through the second module heat exchanger 930 may exchange heat with each other. The third main refrigerant may dissipate heat to the second regeneration refrigerant while being condensed in the second module heat exchanger 930 and be converted into a liquid refrigerant. Accordingly, the third main refrigerant may dissipate heat more effectively, and the operating high pressure of the third main refrigerant cycle of the third air-conditioning unit U3 may be decreased, thereby improving efficiency and reducing power consumption.

[0279] Conversely, as the second regeneration refrigerant evaporates in the second module heat exchanger 930, the second regeneration refrigerant may absorb heat from the third main refrigerant flowing through the second module heat exchanger 930. In this case, the amount of absorbed heat may increase because the temperature of the third main refrigerant is high. Accordingly, the operating low pressure of the second regeneration refrigerant cycle constituting the third air-conditioning unit U3 may be increased, thereby reducing power consumption. By increasing the air discharge temperature of the second regeneration heat exchanger 470 constituting the second regeneration refrigerant cycle to about 50° C. or higher, the air may be delivered toward the first regeneration heat exchanger 450 in the direction K3. The air delivered in this way may be used as regeneration energy of the high-temperature regeneration type the dehumidifying rotor 460. Accordingly, the usage of the regeneration heater 465 with low efficiency may be reduced, thereby further increasing energy efficiency.

[0280] In particular, the third main refrigerant may cool and dehumidify air while evaporating in the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435. For the evaporation in the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435, the second module heat exchanger 930 must condense the third main refrigerant while dissipating heat. The heat dissipation energy generated during this process may be absorbed by the second regeneration refrigerant cycle, so that the air discharge temperature generated when the second regeneration heat exchanger dissipates heat may be further increased. Accordingly, the usage of the dehumidification heater 365 may be further reduced.

[0281] Referring to FIG. 11, outside air OA sucked in from the outside may be heated while passing through the second regeneration heat exchanger 470 constituting the third air-conditioning unit U3, and the heated air may be delivered toward the first regeneration heat exchanger 450 in the direction K3. In addition, when the air that has previously passed through the dehumidifying rotor 460 is transferred toward the third indoor heat exchanger 430 in the direction K2, the air may pass through the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 in sequence. In this process, the air may be dehumidified fourthly and fifthly, and thus may have very low humidity. In addition, the air with the reduced humidity may be supplied to the indoor space through the air supply opening G3.

[0282] Next, the third air-conditioning mode will be described. First, referring to FIG. 3, a schematic operation of the third air-conditioning mode is shown. When the third air-conditioning mode is selected in S320, the operations of components constituting the first air-conditioning unit U1, the second air-conditioning unit U2, and the third air-conditioning unit U3 may be controlled in S420. Specifically, the first outdoor compressor 110, the second outdoor compressor 210, the third outdoor compressor 310, the first module compressor 710, and the second module compressor 910 may be operated.

[0283] The first outdoor heat exchanger 130, the third outdoor heat exchanger 330, the first recovery heat exchanger 410, the first regeneration heat exchanger 450, the second regeneration heat exchanger 470, the first module heat exchanger 730, and the second module heat exchanger 930 may each be operated as a condenser. In addition, the second outdoor heat exchanger 230, the first indoor heat exchanger 421, the second indoor heat exchanger 425, 322, the third indoor heat exchanger 430, the fourth indoor heat exchanger 435, the second recovery heat exchanger 440, 350, the first module heat exchanger 730, and the second module heat exchanger 930 may each be operated as an evaporator.

[0284] As described above, the first module heat exchanger 730 and the second module heat exchanger 930 may be configured as plate heat exchangers and thus may be the condenser of the second main refrigerant and the third main refrigerant and the evaporator of the first regeneration refrigerant and the second regeneration refrigerant.

[0285] FIGS. 12 to 15 illustrate the flow of the main refrigerant in the third air-conditioning mode. The third air-conditioning mode may perform the function of cooling air to lower the indoor temperature along with dehumidification.

[0286] Among these, in FIG. 12, the main refrigerant flow and the regeneration refrigerant flow are indicated by arrows in the third air-conditioning mode, in FIG. 13, the first main refrigerant flow in the first air-conditioning unit U1 is illustrated in the form of a flowchart, and in FIG. 14, the second main refrigerant flow and the first regeneration refrigerant flow in the second air-conditioning unit U2 are illustrated in the form of a flowchart. In FIG. 15, the third main refrigerant flow and the second regeneration refrigerant flow in the third air-conditioning unit U3 are illustrated in the form of a flowchart.

[0287] First, referring to FIGS. 12 and 13, when looking at the flow of a refrigerant in the first air-conditioning unit U1 in the third air-conditioning mode, the first outdoor compressor 110 may compress the first main refrigerant and discharge the high-temperature, high-pressure first main refrigerant through the first compressor discharge pipe L101. A portion of the discharged high-temperature, high-pressure first main refrigerant may be delivered to the first recovery heat exchanger 410, and the remaining portion thereof may be delivered to the first outdoor heat exchanger 130. That is, the first recovery heat exchanger 410 and the first outdoor heat exchanger 130 may each be used as a condenser.

[0288] In this case, the path through which a refrigerant flows to the first recovery heat exchanger 410 may be the first high-pressure pipe. Here, the first high-pressure pipe may include the first compressor discharge pipe L101, the first-1 outdoor device connection pipe L103, and the first-1 distribution connection pipe L105. In this case, the first refrigerant distribution valve 510 of the first transfer module 500 may be arranged between the first-1 outdoor device connection pipe L103 and the first-1 distribution connection pipe L105, and the first refrigerant distribution valve 510 may connect the first-1 outdoor device connection pipe L103 and the first-1 distribution connection pipe L105 to each other.

[0289] In addition, the path through which a refrigerant flows to the first outdoor heat exchanger 130 may also be the first high-pressure pipe. Here, the first high-pressure pipe may include the first compressor discharge pipe L101 and the first-1 outdoor heat exchange connection pipe L102. For reference, in this case, the first main outdoor valve 150 and the first sub-outdoor valve 160 may be considered as being in an OFF state.

[0290] Here, the first recovery heat exchanger 410 may be supplied with a greater flow rate of the first main refrigerant than the first outdoor heat exchanger 130.

[0291] For approximately 70% of the first main refrigerant may be supplied to the first recovery heat exchanger 410, and approximately 30% of the first main refrigerant may be supplied to the first outdoor heat exchanger 130.

[0292] The first main refrigerant condensed in the first recovery heat exchanger 410 may be in a medium temperature, high pressure state and may be delivered to the first indoor heat exchanger421 and the second indoor heat exchanger 425. In this case, the path of the first main refrigerant flowing to the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may be the first liquid pipe. Specifically, the first indoor device connection pipe L128 may be the first liquid pipe through which a refrigerant flows to the first indoor heat exchanger 421, and the first indoor device connection pipe L128 and the first indoor branch pipe L125 may be the first liquid pipe through which a refrigerant flows to the second indoor heat exchanger 425.

[0293] The first indoor expansion valve 423 may be arranged in the first-1 indoor heat exchange connection pipe L124, so that a refrigerant may flow to the first indoor heat exchanger 421, which is an evaporator, in an expanded state in the first indoor expansion valve 423. The second indoor expansion valve 427 is arranged in the first-2 indoor heat exchange connection pipe L126, so that the first main refrigerant may flow to the second indoor heat exchanger 425, which is the evaporator, in an expanded state in the second indoor expansion valve 427. The second indoor expansion valve 427 may be arranged on the first-2 indoor heat exchange connection pipe L126, so that the first main refrigerant may flow to the second indoor heat exchanger 425, which is an evaporator, in an expanded state in the second indoor expansion valve 427.

[0294] Since the first indoor heat exchanger 421 and the second indoor heat exchanger 425 each serve as the evaporator, the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may cool and dehumidify air inside the indoor duct S. Outside air OA, which has been primarily cooled and dehumidified while passing through the first indoor heat exchanger 421, may be secondarily cooled and dehumidified while passing through the second indoor heat exchanger 425. In FIG. 13, the outside air OA passing through the first indoor heat exchanger 421 and the second indoor heat exchanger 425 is indicated by bold arrows.

[0295] The first indoor heat exchanger 421 and the second indoor heat exchanger 425 may be supplied with first main refrigerants in different proportions. The first indoor heat exchanger 421, which is closer to the first recovery heat exchanger 410, may be supplied with a larger amount of the first main refrigerant than the second indoor heat exchanger 425. This is because a larger amount of the first main refrigerant was supplied to the first recovery heat exchanger 410 than to the first outdoor heat exchanger 130 under the previous control of the controller 1000. For example, approximately 70% of the first main refrigerant may be supplied to the first indoor heat exchanger 421, and approximately 30% of the first main refrigerant may be supplied to the second indoor heat exchanger 425.

[0296] In this case, the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may be arranged side by side along the direction of an air flow inside the indoor duct S. Accordingly, the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may continuously cool and dehumidify the outside air OA. The outside air OA cooled by the first indoor heat exchanger 421 and the second indoor heat exchanger 425 may thirdly be dehumidified while continuously flowing and passing through the dehumidifying rotor 460, and finally, may fourthly and fifthly be cooled and dehumidified by the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 to be the supply air SA, which may be supplied to the indoor space through the air supply opening G3. The third to fifth dehumidification structures will be described again below.

[0297] The low temperature, low pressure first main refrigerant discharged from the first indoor heat exchanger 421 may be introduced into the first transfer module 500 through the first heat exchange guide pipe L117, and may be delivered to the first refrigerant heat exchanger 530 through the first heat exchange connection pipe L116 inside the first transfer module 500. In addition, the first main refrigerant may be supplied to the first accumulator 120 through the first accumulator connection pipe L111 and the first accumulator suction pipe L113, and then suctioned back into the first outdoor compressor 110 through the first compressor suction pipe L115. Accordingly, the first heat exchange guide pipe L117, the first heat exchange connection pipe L116, the first accumulator connection pipe L111, and the first accumulator suction pipe L113 may be a first low-pressure pipe.

[0298] The low temperature, low pressure first main refrigerant discharged from the second indoor heat exchanger 425 may be introduced into the first transfer module 500 through the first-2 distribution connection pipe L119, and may join the first refrigerant heat exchanger 530 through the first refrigerant distribution valve 510 inside the first transfer module 500. In addition, the first main refrigerant may be supplied to the first accumulator 120 through the first accumulator connection pipe L111 and the first accumulator suction pipe L113, and then may be suctioned back into the first outdoor compressor 110 through the first compressor suction pipe L115.

[0299] In this case, the first refrigerant heat exchanger 530 may exchange heat between the low-temperature, low-pressure first main refrigerant discharged from the first indoor heat exchanger 421 and the second indoor heat exchanger 425, and the medium-temperature, high-pressure first main refrigerant condensed in the first outdoor heat exchanger 130. The medium-temperature, high-pressure first main refrigerant condensed in the first outdoor heat exchanger 130 may dissipate heat (heat exchange) to the low-temperature, low-pressure first main refrigerant discharged from the first indoor heat exchanger 421 and the second indoor heat exchanger 425 while passing through the first refrigerant heat exchanger 530. Accordingly, the medium-temperature, high-pressure first main refrigerant may be supplied to the first indoor heat exchanger 421 and the second indoor heat exchanger 425 while being in in a liquid refrigerant state.

[0300] Looking at the first recovery heat exchanger 410 that operates as a condenser, the first recovery heat exchanger 410 may operate as the condenser and the first main refrigerant of the first recovery heat exchanger 410 may dissipate heat toward exhaust air EA. That is, the first main refrigerant of the first recovery heat exchanger 410 may dissipate heat to the exhaust air EA while exchanging heat with the exhaust air EA discharged through the first exhaust outlet G5. In FIG. 13, the return air RA passing through the first recovery heat exchanger 410, and the first main refrigerant of the first recovery heat exchanger 410 dissipating heat to the exhaust air EA are indicated by bold arrows.

[0301] In this case, a portion of the air supplied to the first recovery heat exchanger 410 may be return air RA drawn in from an indoor space and have a temperature lower than the temperature of the outside air. In this way, the exhaust air EA, which exchanges heat with the first recovery heat exchanger 410, may have a temperature lower than the outside air, so that the heat of the first main refrigerant passing through the first recovery heat exchanger 410 may be dissipated more effectively. That is, by utilizing the waste heat of the exhaust air EA, the heat of the first main refrigerant of the first recovery heat exchanger 410 may be dissipated more effectively. Accordingly, the operating high pressure of the refrigeration cycle of the first air-conditioning unit U1 may be lowered, thereby improving efficiency and reducing power consumption.

[0302] For example, when an outside temperature is high in a transitional season, the first main refrigerant of the first recovery heat exchanger 410 may have difficulty dissipating heat to the outside air, and a cooling overload phenomenon may occur. However, in this embodiment, air that exchanges heat with the first main refrigerant of the first recovery heat exchanger 410 may be return air RA supplied from indoors, so a temperature thereof may be lower than that of the outside air, and therefore, heat may be dissipated smoothly without an overload.

[0303] Meanwhile, the first heat recovery expansion valve 415 may be arranged on the first heat recovery connection pipe L127 connected to the first recovery heat exchanger 410. The controller 1000 may control the opening rate of the first heat recovery expansion valve 415 to control the flow rate of the high-temperature, high-pressure first main refrigerant supplied to the first recovery heat exchanger 410. The flow rate of the high-temperature, high-pressure first main refrigerant discharged from the first outdoor compressor 110 may be fixed, and thus when the flow rate of the first main refrigerant supplied to the first recovery heat exchanger 410 is controlled, the flow rate of the first main refrigerant supplied to the first outdoor heat exchanger 130 may also be controlled. Through this refrigerant flow rate control, the degree of waste heat recovery through the first recovery heat exchanger 410 may also be controlled.

[0304] For example, (i) when the temperature (indoor temperature) of the return air RA introduced through the return air inlet G4 is lower than the outside temperature, it is more effective for the first main refrigerant of the first recovery heat exchanger 410 to dissipate heat to the return air RA than to dissipate heat to the outside air while the first recovery heat exchanger 410 operates as a condenser. However, (ii) when the temperature (indoor temperature) of the return air RA introduced through the return air inlet G4 is higher than the outside temperature, it is less efficient for the first main refrigerant of the first recovery heat exchanger 410 to dissipate heat to the return air RA than to the outside air when the first recovery heat exchanger 410 operates as the condenser. In this case, by controlling the opening rate of the first heat recovery expansion valve 415, the flow rate of the first main refrigerant introduced into the first recovery heat exchanger 410, which is a condenser, may be reduced and the flow rate of the first main refrigerant introduced into the first outdoor heat exchanger 130, which is another condenser, may be increased, thereby improving heat dissipation efficiency.

[0305] Next, referring to FIGS. 12 and 14, when looking at the flow of a refrigerant in the second air-conditioning unit U2 in the third air-conditioning mode, the second outdoor compressor 210 may compress the second main refrigerant and discharge a high-temperature, high-pressure second main refrigerant through the second compressor discharge pipe L201. All of the discharged high-temperature, high-pressure second main refrigerant may be delivered to the first heat exchange module 700 of the first heat exchange module 700 through the second transfer module 600. The first module heat exchanger 730 may be the condenser of the second main refrigerant cycle.

[0306] In this case, the path through which the second main refrigerant flows to the first heat exchange module 700 may be the second high-pressure pipe. Here, the second high-pressure pipe may include the second compressor discharge pipe L201, the second-1 outdoor device connection pipe L203, and the second-1 distribution connection pipe L205. In this case, the second refrigerant distribution valve 610 of the second transfer module 600 may be arranged between the second-1 outdoor device connection pipe L203 and the second-1 distribution connection pipe L205, and the second refrigerant distribution valve 610 may connect the second-1 outdoor device connection pipe L203 and the second-1 distribution connection pipe L205 to each other. For reference, in this case, the second main outdoor valve 250 and the second sub-outdoor valve 260 may be considered as being in OFF states.

[0307] In the process in which the second main refrigerant passes through the first module heat exchanger 730, the second main refrigerant may exchange heat with the first regeneration refrigerant flowing through the first module heat exchanger 730. As described above, the first regeneration heat exchanger 450, together with the first heat exchange module 700, may constitute a separate first regeneration refrigerant cycle that allows the first regeneration refrigerant to flow. Here, heat generated in the first regeneration heat exchanger 450, which operates as a condenser, may be transferred to the dehumidifying rotor 460. Air drawn in through the second outside air opening G2, air delivered through the second bypass B2, and air passing through the second regeneration heat exchanger470 may undergo heat exchange while passing through the first regeneration heat exchanger 450, thereby further increasing temperatures thereof.

[0308] In addition, the air thus heated may be delivered to the dehumidifying rotor 460 to regenerate the dehumidifying rotor 460. Accordingly, the usage of the regeneration heater 465 for regenerating the dehumidifying rotor 460 may be reduced, thereby reducing power consumption for operating the second air-conditioning unit U2. In FIG. 14, the flow of air that has dissipated heat in the first regeneration heat exchanger 450 and passes through the dehumidifying rotor 460 is indicated by a bold arrow.

[0309] At the same time, the first regeneration refrigerant may flow through the first regeneration refrigerant cycle, which consists of the first heat exchange module 700 and the first regeneration heat exchanger 450. The first module compressor 710 may discharge the compressed high-temperature, high-pressure first regeneration refrigerant through the discharge pipe L245 of the first module compressor 710. The discharged high-temperature, high-pressure first regeneration refrigerant may be delivered to the first regeneration heat exchanger 450, and the first regeneration heat exchanger 450 may condense the first regeneration refrigerant.

[0310] During the process in which the first regeneration heat exchanger 450 condenses the first regeneration refrigerant, the first regeneration refrigerant may dissipate heat, and after the heat dissipation, the first regeneration refrigerant may be converted into a medium-temperature, high-pressure liquid refrigerant. In addition, the first regeneration refrigerant may be delivered to the first module expansion valve 740 through the first regeneration heat exchange connection pipe L247 to be expanded, and then delivered to the first module heat exchanger 730 through the first module heat exchange connection pipe L248 to be evaporated. The evaporated first regeneration refrigerant may be delivered to the first module accumulator through the first module accumulator suction pipe L241.

[0311] In this case, the second main refrigerant and the first regeneration refrigerant passing through the first module heat exchanger 730 may exchange heat with each other. The second main refrigerant may be converted into a liquid refrigerant by dissipating heat to the first regeneration refrigerant while being condensed in the first module heat exchanger 730. Accordingly, the second main refrigerant may dissipate heat more effectively, and the operating high pressure of the second main refrigerant cycle of the second air-conditioning unit U2 may be lowered, thereby improving efficiency and reducing power consumption.

[0312] Conversely, as the first regeneration refrigerant evaporates in the first module heat exchanger 730, the first regeneration refrigerant may absorb heat from the second main refrigerant flowing through the first module heat exchanger 730. In this case, the amount of absorbed heat may increase since the temperature of the second main refrigerant is high. Accordingly, the operating low pressure of the first regeneration refrigerant cycle that constitutes the second air-conditioning unit U2 may increase, thereby reducing power consumption. In particular, by raising the air discharge temperature of the first regeneration heat exchanger 450, which constitutes the first regeneration refrigerant cycle, to approximately 60° C. or higher, discharged air may be used as regeneration energy for the high-temperature regeneration dehumidifying rotor 460. This, in turn, may reduce the usage of the less efficient regeneration heater 465, thereby further improving energy efficiency.

[0313] In this case, air heated while passing through the second regeneration heat exchanger 470, which constitutes the third air-conditioning unit U3, may be delivered toward the first regeneration heat exchanger 450 in the direction K3. Referring to FIG. 14, the air flow is indicated by bold arrows. The air delivered toward the first regeneration heat exchanger 450 in direction K3 may be further heated by the first regeneration heat exchanger 450 before being delivered to the dehumidifying rotor 460. In addition, the air that has regenerated the dehumidifying rotor 460 at high temperature may be delivered to the second recovery heat exchanger 440. The air passing through the second recovery heat exchanger 440 may be exhaust air EA.

[0314] Meanwhile, a portion of the second main refrigerant that is condensed through heat exchange in the second module heat exchanger 930 may be delivered to the second recovery heat exchanger 440 to be evaporated, and the remaining portion thereof may be delivered to the second outdoor heat exchanger to be evaporated.

[0315] The medium-temperature, high-pressure second main refrigerant condensed in the first module heat exchanger 730 may evaporate in the second recovery heat exchanger 440 and the second outdoor heat exchanger 230. In this case, the path through which a refrigerant flows to the second recovery heat exchanger 440 and the second outdoor heat exchanger 230 may be the second liquid pipe.

[0316] Specifically, the first main connection pipe L224 and a second heat recovery connection pipe L225 may be the second liquid pipe through which the second main refrigerant flows to the second recovery heat exchanger 440. In addition, the first module connection pipe L223 and the second-2 outdoor device connection pipe L222 may be the second liquid pipe through which the second main refrigerant flows to the second outdoor heat exchanger 230.

[0317] In this case, the second main refrigerant in the second recovery heat exchanger 440 may absorb heat from exhaust air EA discharged from the indoor device 400 to the outside. In this case, since the exhaust air EA has a higher temperature than the outside air, the amount of absorbed heat may increase. Accordingly, the operating low pressure of the refrigeration cycle in the second air-conditioning unit U2 may increase, thereby reducing power consumption.

[0318] As a result, when the second recovery heat exchanger 440 operates as an evaporator, the second recovery heat exchanger 440 may utilize the temperature of the exhaust air EA, thereby reducing power consumption required to operate the refrigeration cycle of the second air-conditioning unit U2.

[0319] The low-temperature, low-pressure second main refrigerant evaporated in the second recovery heat exchanger 440 may flow into the second transfer module 600 through the second heat exchange transfer pipe L217. In addition, the second main refrigerant passing through the second refrigerant heat exchanger 630 via the second heat exchange connection pipe L216 may be drawn into the second outdoor compressor 210 through the second accumulator. Accordingly, the second heat exchange transfer pipe L217, the second heat exchange connection pipe L216, the second accumulator connection pipe L211, and the second accumulator suction pipe L213 may be the second low-pressure pipe.

[0320] Meanwhile, air that has passed through the second indoor heat exchanger may 425 flow toward the dehumidifying rotor 460 in the direction K1 and may be dehumidified while passing through the dehumidifying rotor 460. The dehumidified air may be delivered toward the third indoor heat exchanger 430 in the direction K2.

[0321] In FIGS. 12 and 14, the flow of air through the dehumidifying rotor 460 is indicated by a bold arrow.

[0322] In this case, a portion of the dehumidifying rotor 460 may be arranged within the indoor duct S in the direction of an air flow. Accordingly, the dehumidifying rotor 460 may again dehumidify the outside air OA passing through the first indoor heat exchanger 421 and the second indoor heat exchanger 425, thereby allowing for a total of three consecutive dehumidification processes and significantly reducing the humidity of outside air OA.

[0323] Next, referring to FIG. 12 and FIG. 15, when looking at the flow of the third main refrigerant in the third air-conditioning unit U3 in the third air-conditioning mode, the third outdoor compressor 310 may compress the third main refrigerant and discharge a high-temperature, high-pressure third main refrigerant through the third compressor discharge pipe L301. A portion of the discharged high-temperature, high-pressure third main refrigerant may be delivered to the second module heat exchanger 930 through the third transfer module 800, and the remaining portion thereof may be delivered to the third outdoor heat exchanger 330. The second module heat exchanger 930 and the third outdoor heat exchanger 330 may each be used as a condenser.

[0324] In this case, the path through which the refrigerant flows to the second module heat exchanger 930 may be the second high-pressure pipe. Here, the second high-pressure pipe may include the third compressor discharge pipe L301, the third-1 outdoor device connection pipe L303, and the third-1 distribution connection pipe L305. In this case, the third refrigerant distribution valve 810 of the third transfer module 800 may be arranged between the third-1 outdoor device connection pipe L303 and the third-1 distribution connection pipe L305, and the third refrigerant distribution valve 810 may connect the third-1 outdoor device connection pipe L303 and the third-1 distribution connection pipe L305 to each other.

[0325] The third main refrigerant condensed in the second module heat exchanger 930 may be in a medium-temperature, high-pressure state and may be delivered to the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435. In this case, the third main refrigerant condensed by the third outdoor heat exchanger 330 may be mixed with the third main refrigerant condensed in the second module heat exchanger 930 through the third refrigerant heat exchanger 830. The third main refrigerant thus mixed may be delivered to the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435.

[0326] In this case, low-temperature, low-pressure third main refrigerants that have been evaporated in the third and fourth indoor heat exchangers 430 and 435 may flow through the third refrigerant heat exchanger 830. Accordingly, the medium-temperature, high-pressure third main refrigerant that has been condensed by the third outdoor heat exchanger 330 may be converted into a liquid refrigerant by dissipating heat (heat exchange) to the low-temperature, low-pressure third main refrigerant when passing through the third refrigerant heat exchanger 830, and then may be mixed with the third main refrigerant condensed in the second module heat exchanger 930.

[0327] The path through which the refrigerant flows to the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 may be the third liquid pipe. Specifically, the third-2 outdoor device connection pipe L322, the second main connection pipe L323, and the fourth heat exchange transfer pipe L324 may constitute the third liquid pipe through which a refrigerant flows to the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435.

[0328] The first indoor heat exchanger 421, the second indoor heat exchanger 425, a portion of the dehumidifying rotor 460, the third indoor heat exchanger 430, and the fourth indoor heat exchanger 435 may be arranged sequentially along the direction of an air flow inside the indoor duct S. Accordingly, the first indoor heat exchanger 421, the second indoor heat exchanger 425, a portion of the dehumidifying rotor 460, the third indoor heat exchanger 430, and the fourth indoor heat exchanger 435 may significantly reduce the humidity of outside air OA by continuously dehumidifying the outside air OA a total of five times.

[0329] The low-temperature, low-pressure third main refrigerant discharged from the third indoor heat exchanger 430 may be introduced into the third transfer module 800 through the third heat exchange transfer pipe L317, and may be delivered to the third refrigerant heat exchanger 830 through the third heat exchange connection pipe L316 inside the third transfer module 800. At the same time, the low-temperature, low-pressure third main heat refrigerant discharged from the fourth indoor h exchanger 435 may be introduced into the third transfer module 800 through the third-2 distribution connection pipe L319 and delivered to the third refrigerant heat exchanger 830 through the third refrigerant distribution valve 810 inside the third transfer module 800.

[0330] In addition, the third main refrigerant that has passed through the third refrigerant heat exchanger 830 may be supplied to the third accumulator 420 through the third accumulator connection pipe L311 and the third accumulator suction pipe L313, and then suctioned back into the third outdoor compressor 310 through the third compressor suction pipe L315. Accordingly, the third-2 distribution connection pipe L319, the third heat exchange connection pipe L316, the third accumulator connection pipe L311, and the third accumulator suction pipe L313 may constitute a third low-pressure pipe.

[0331] In this case, the third refrigerant heat exchanger 830 may exchange heat between the low-temperature, low-pressure third main refrigerant discharged from the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 and the medium-temperature, high-pressure refrigerant condensed in the third outdoor heat exchanger 330. The medium-temperature, high-pressure refrigerant condensed in the third outdoor heat exchanger 330 may dissipate heat to the low-temperature, low-pressure refrigerant discharged from the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 while passing through the third refrigerant heat exchanger 830. Accordingly, the medium-temperature, high-pressure third main refrigerant may be supplied to the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 while being in a liquid refrigerant state.

[0332] At the same time, the second regeneration refrigerant may flow in the second regeneration refrigerant cycle which consists of the second heat exchange module 900 and the second regeneration heat exchanger 470. The second module compressor 910 may discharge the compressed high-temperature, high-pressure second regeneration refrigerant through the discharge pipe L345 of the second module compressor 910. The discharged high-temperature, high-pressure second regeneration refrigerant may be delivered to the second regeneration heat exchanger 470, and the second regeneration heat exchanger 470 may condense the second regeneration refrigerant.

[0333] During the process in which the second regeneration heat exchanger 470 condenses the second regeneration refrigerant, the second regeneration refrigerant may dissipate heat, and after the heat dissipation, the second regeneration refrigerant may be converted into a medium-temperature, high-pressure liquid refrigerant. In addition, the second regeneration refrigerant may be delivered to the second module expansion valve 940 through the second regeneration heat exchange connection pipe L347 to be expanded, and then delivered to the second module heat exchanger 930 to be evaporated. The evaporated second regeneration refrigerant may be delivered to the second module accumulator through the second module accumulator suction pipe L341.

[0334] In this case, the third main refrigerant and the second regeneration refrigerant passing through the second module heat exchanger 930 may exchange heat with each other. The third main refrigerant may be converted into a liquid refrigerant by dissipating heat to the second regeneration refrigerant while being condensed in the second module heat exchanger 930. Accordingly, the third main refrigerant may dissipate heat more effectively, and the operating high pressure of the third main refrigerant cycle of the third air-conditioning unit U3 may be lowered, thereby improving efficiency and reducing power consumption.

[0335] Conversely, as the second regeneration refrigerant evaporates in the second module heat exchanger 930, the second regeneration refrigerant may absorb heat from the third main refrigerant flowing through the second module heat exchanger 930. In this case, since the temperature of the third main refrigerant is high, a heat absorption amount may increase. Accordingly, the operating low pressure of the second regeneration refrigerant cycle constituting the third air-conditioning unit U3 may be increased, thereby reducing power consumption. By raising the air discharge temperature of the second regeneration heat exchanger 470 constituting the second regeneration refrigerant cycle to approximately 40° C. or higher, discharged air may be delivered toward the first regeneration heat exchanger 450 in the direction K3. The air delivered in this way may be used as regeneration energy for the high-temperature regeneration type dehumidifying rotor 460. Accordingly, the usage of the low efficiency regeneration heater 465 may be reduced, thereby further increasing energy efficiency.

[0336] In particular, the third main refrigerant may cool and dehumidify air while evaporating in the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435. For the evaporation in the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435, the second module heat exchanger 930 must condense the third main refrigerant while dissipating heat. Heat dissipation energy generated during this process may be absorbed by the second regeneration refrigerant cycle, so that the air discharge temperature generated when the second regeneration heat exchanger dissipates heat may be further increased. Accordingly, the usage of the dehumidification heater 365 may be further reduced.

[0337] Referring to FIG. 15, outside air OA drawn in from the outside may be heated while passing through the second regeneration heat exchanger 470 constituting the third air-conditioning unit U3, and the heated air may be delivered toward the first regeneration heat exchanger 450 in the direction K3. In addition, when the air that has previously passed through the dehumidifying rotor 460 is delivered toward the third indoor heat exchanger 430 in the direction K2, the air may pass through the third indoor heat exchanger 430 and the fourth indoor heat exchanger 435 in sequence. In this process, the air may be fourthly and fifthly dehumidified, so that the air may have very low humidity. In addition, the air with reduced humidity may be supplied to the indoor space through the air supply opening G3.

[0338] Meanwhile, FIG. 16 illustrates a schematic configuration of the air conditioner according to the second embodiment of the present disclosure. Looking at difference from the previous embodiment, the third air-conditioning unit U3 may be omitted. That is, the air conditioner in the second embodiment may be composed of only the first air-conditioning unit U1 and the second air-conditioning unit U2. In this case, outside air OA may be dehumidified in three stages by passing through the first indoor heat exchanger 421, the second indoor heat exchanger 425, and the dehumidifying rotor 460.

[0339] Even in the second embodiment, the second air-conditioning unit U2 may include the first heat exchange module 700. The first heat exchange module 700 may allow the independent first regeneration refrigerant to flow and exchange heat with the second main refrigerant discharged from the second outdoor compressor 210.

[0340] Next, FIG. 17 illustrates a schematic configuration of the air conditioner according to the third embodiment of the present disclosure. Looking at difference from the previous embodiment, two heat exchangers included in the indoor device 400 may be connected in parallel. For example, a first recovery heat exchanger 1410 may include a first-1 recovery heat exchanger 1410a and a first-2 recovery heat exchanger 1410b arranged in parallel. For a first indoor heat exchanger 1421, a first-1 indoor heat exchanger 1421a and a first-2 indoor heat exchanger 1421b may be arranged in parallel to constitute one first indoor heat exchanger 1421.

[0341] In this way, when a plurality of heat exchangers are connected in parallel to constitute a single heat exchanger, the cooling, heating, and dehumidifying capacity of the air conditioner may be increased. Accordingly, the air conditioner may be applied to larger buildings or factories.

[0342] A structure for configuring a plurality of heat exchangers in parallel is illustrated in FIGS. 18 to 20. Referring to FIG. 18, the first recovery heat exchanger 1410 is represented as being composed of the first-1 recovery heat exchanger 1410a and the first-2 recovery heat exchanger 1410b. The first-1 recovery heat exchanger 1410a and the first-2 recovery heat exchanger 1410b may have a structure (an intertwined coil structure) in which they are arranged alternately in a vertical direction. The first-1 recovery heat exchanger 1410a and the first-2 recovery heat exchanger 1410b, which are arranged alternately in this way, may secure a larger area through parallel connection, and increase the cooling, heating, and dehumidifying capacity of the air conditioner.

[0343] Referring to FIG. 19, the first recovery heat exchanger 1410 is represented as consisting of the first-1 recovery heat exchanger 1410a and the first-2 recovery heat exchanger 1410b. The first-1 recovery heat exchanger 1410a and the first-2 recovery heat exchanger 1410b may have a structure in which they are stacked vertically. The first-1 recovery heat exchanger 1410a may be arranged on a relatively upper side, and the first-2 recovery heat exchanger 1410b may be arranged on a lower side. The first-1 recovery heat exchanger 1410a and the first-2 recovery heat exchanger 1410b, which are stacked on each other in this way, may secure a larger area through parallel connection, and increase the cooling, heating, and dehumidifying capacity of the air conditioner.

[0344] Referring to FIG. 20, the first recovery heat exchanger 1410 is represented as consisting of the first-1 recovery heat exchanger 1410a and the first-2 recovery heat exchanger 1410b. The first-1 recovery heat exchanger 1410a and the first-2 recovery heat exchanger 1410b may have a structure in which they are arranged left and right along the side. The first-1 recovery heat exchanger 1410a may be arranged relatively on the left side, and the first-2 recovery heat exchanger 1410b may be arranged relatively on the right side. The first-1 recovery heat exchanger 1410a and the first-2 recovery heat exchanger 1410b, which are arranged left and right in this way, may secure a larger area through parallel connection and increase the cooling, heating, and dehumidifying capacity of the air conditioner. Although not shown, the first-1 recovery heat exchanger 1410a and the first-2 recovery heat exchanger 1410b may also be arranged left and right with respect to the front.

[0345] The above explanation is only an example of the technical idea of the present disclosure, and those skilled in the art to which the present disclosure belongs may make various modifications and variations without departing from the essential characteristics of the present disclosure. Accordingly, the embodiments disclosed in the present disclosure are intended to illustrate rather than limit the technical ideas of the present disclosure, and the scope of the technical ideas of the present disclosure is not limited by these embodiments. The scope of protection of the present disclosure should be interpreted by the claims below, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of protection of the present disclosure.

Claims

1. An air conditioner comprising:an outdoor unit comprising a plurality of outdoor devices independent of each other;an indoor unit connected to the plurality of outdoor devices, and having an indoor duct that supplies external air or indoor air to an indoor space, and a dehumidifying rotor arranged therein to dehumidify air inside the indoor duct;a transfer unit disposed between the outdoor unit and the indoor unit and configured to transfer a main refrigerant between the outdoor unit and the indoor unit; anda heat exchange unit disposed between the transfer unit and the indoor unit, and comprising a module compressor that compresses a regeneration refrigerant flowing independently of the main refrigerant, and a module heat exchanger through which each of the main refrigerant and the regeneration refrigerant circulate,wherein the module heat exchanger condenses the main refrigerant and evaporates the regeneration refrigerant, andwherein the module heat exchanger exchanges heat between the main refrigerant and the regeneration refrigerant.

2. The air conditioner of claim 1, wherein a first regeneration heat exchanger which constitutes a regeneration refrigerant cycle together with the heat exchange unit is disposed in the indoor unit,wherein the first regeneration heat exchanger condenses the regeneration refrigerant compressed in the module compressor, and while condensing the regeneration refrigerant, the first regeneration heat exchanger dissipates heat to air flowing to the dehumidifying rotor.

3. The air conditioner of claim 1, wherein the indoor unit further comprises:a plurality of indoor heat exchangers that exchange heat between the air inside the indoor duct and the main refrigerant; anda first recovery heat exchanger disposed on a first exhaust outlet through which the air inside the indoor duct is discharged to the outside, and constituting a main refrigerant cycle together with one of the plurality of outdoor devices and the indoor heat exchangers,wherein the first recovery heat exchanger exchanges heat between exhaust air discharged to the outside through the first exhaust outlet and the main refrigerant.

4. The air conditioner of claim 1, wherein the outdoor unit comprises a first outdoor device, a second outdoor device, and a third outdoor device which are independent of each other, and the main refrigerant comprises a first main refrigerant compressed in the first outdoor device, a second main refrigerant compressed in the second outdoor device, and a third main refrigerant compressed in the third outdoor device,wherein the indoor unit comprises:a first indoor heat exchanger, a second indoor heat exchanger, and a first recovery heat exchanger which constitute a first main refrigerant cycle together with the first outdoor device;a second recovery heat exchanger which constitutes a second main refrigerant cycle together with the second outdoor device; anda third indoor heat exchanger and a fourth indoor heat exchanger which constitute a third main refrigerant cycle together with the third outdoor device.

5. The air conditioner of claim 4, wherein the transfer unit comprises:a first transfer module disposed between the first outdoor device and the indoor unit and configured to transfer the first main refrigerant between the first outdoor device and the indoor unit;a second transfer module disposed between the second outdoor device and the indoor unit and configured to transfer the second main refrigerant between the second outdoor device and the indoor unit; anda third transfer module disposed between the third outdoor device and the indoor unit and configured to transfer the third main refrigerant between the third outdoor device and the indoor unit,wherein the heat exchange unit comprises:a first heat exchange module disposed between the second transfer module and the indoor unit and configured to operate a first regeneration refrigerant; anda second heat exchange module disposed between the third transfer module and the indoor unit and configured to operate a second regeneration refrigerant.

6. The air conditioner of claim 5, wherein the first heat exchange module comprises:a first module compressor configured to compress the first regeneration refrigerant;a first module expansion valve connected to a first regeneration heat exchanger and configured to expand the condensed first regeneration refrigerant; anda first module heat exchanger configured to evaporate the first regeneration refrigerant and condense the first main refrigerant.

7. The air conditioner of claim 6, wherein the second heat exchange module comprises:a second module compressor configured to compress the second regeneration refrigerant;a second module expansion valve connected to a second regeneration heat exchanger of the indoor unit and configured to expand the condensed second regeneration refrigerant; anda second module heat exchanger configured to evaporate the second regeneration refrigerant and condense the second main refrigerant.

8. The air conditioner of claim 5, wherein a plurality of indoor heat exchangers comprise:the first indoor heat exchanger and the second indoor heat exchanger connected to the first transfer module; andthe third indoor heat exchanger and the fourth indoor heat exchanger connected to the third transfer module,wherein the first indoor heat exchanger and the second indoor heat exchanger are sequentially arranged along a path of the indoor duct.

9. The air conditioner of claim 8, wherein the third indoor heat exchanger and the fourth indoor heat exchanger are sequentially arranged along the path of the indoor duct, and the third indoor heat exchanger is disposed on an opposite side of the second indoor heat exchanger with the dehumidifying rotor placed therebetween.

10. The air conditioner of claim 5, wherein the first recovery heat exchanger is connected to the first transfer module, the first indoor heat exchanger, and the second indoor heat exchanger by respective refrigerant pipes thereof.

11. The air conditioner of claim 5, wherein the first transfer module comprises:a first refrigerant distribution valve configured to control a refrigerant flow between the first outdoor device and the indoor unit; anda first refrigerant heat exchanger configured to exchange heat between the first main refrigerant flowing through a first low-pressure pipe connecting the first indoor heat exchanger and a first outdoor compressor provided in the first outdoor device, and the first main refrigerant flowing through a first liquid pipe connecting the second indoor heat exchanger and a first outdoor heat exchanger.

12. The air conditioner of claim 5, wherein the first transfer module transfers the first main refrigerant compressed by a first outdoor compressor to at least one of a portion of a plurality of indoor heat exchangers and the first recovery heat exchanger.

13. The air conditioner of claim 11, wherein the first indoor heat exchanger is directly connected to the first refrigerant heat exchanger, and the second indoor heat exchanger is connected to the first refrigerant heat exchanger through the first refrigerant distribution valve.

14. The air conditioner of claim 5, wherein the second transfer module transfers the second main refrigerant compressed by a second outdoor compressor of the second outdoor device to the heat exchange unit.

15. The air conditioner of claim 2, wherein a regeneration heater that regenerates the dehumidifying rotor is disposed between the dehumidifying rotor and the first regeneration heat exchanger.

16. The air conditioner of claim 1, wherein the indoor unit comprises:a first exhaust outlet that discharges the air inside the indoor duct to the outside and in which a first recovery heat exchanger is arranged; anda second exhaust outlet that is provided independently of the first exhaust outlet, discharges the air inside the indoor duct to the outside, and has a second recovery heat exchanger arranged therein to exchange heat between exhaust air discharged to the outside and the main refrigerant.

17. The air conditioner of claim 4, wherein the dehumidifying rotor is disposed between a first regeneration heat exchanger and the second recovery heat exchanger.

18. The air conditioner of claim 5, wherein the second transfer module comprises:a second refrigerant distribution valve configured to control the flow of the second main refrigerant between the second outdoor device and the first heat exchange module; anda second refrigerant heat exchanger configured to exchange heat between the second main refrigerant flowing through a second low-pressure pipe connecting the second recovery heat exchanger and a second outdoor compressor of the second outdoor device, and the second main refrigerant flowing through a second liquid pipe connecting a second outdoor heat exchanger of the second outdoor device and the heat exchange unit.

19. The air conditioner of claim 5, wherein the first outdoor device and the first transfer module are connected by refrigerant pipes, and the refrigerant pipes comprise:a first low-pressure pipe connecting a suction part of a first outdoor compressor of the first outdoor device and the first transfer module;a first high-pressure pipe connecting a discharge part of the first outdoor compressor and the first transfer module; anda first liquid pipe connecting a first outdoor heat exchanger of the first outdoor device and the first transfer module.

20. The air conditioner of claim 1, wherein the outdoor unit, the indoor unit, the transfer unit, and the heat exchange unit operate in a first air-conditioning mode, a second air-conditioning mode, or a third air-conditioning mode, which is distinguished according to a condition of an outside air temperature or outside air humidity, and the first air-conditioning mode, the second air-conditioning mode, or the third air-conditioning mode is controlled by a main controller.

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