Air conditioning system

Abstract

The present invention relates to an air conditioning system. The air conditioning system includes a first duct that transports air flowing from an outdoor space to an indoor space, a plurality of heat exchangers arranged inside the first duct, a second duct that transports air discharged from the indoor space to the outdoor space, a first air conditioning device that supplies refrigerant to a first upstream heat exchanger arranged in the first duct and a second duct heat exchanger arranged in the second duct, and a second air conditioning device that supplies refrigerant to at least one first downstream heat exchanger arranged in the first duct. The first air conditioning device includes a first outdoor unit including a first compressor that transports refrigerant to the first upstream heat exchanger or the second duct heat exchanger, and a first outdoor heat exchanger that exchanges heat between refrigerant flowing from the first compressor and air, and a first heat recovery package that exchanges heat between refrigerant flowing from or to the first outdoor unit and refrigerant flowing to the first compressor.

Description

Technical Field

[0001] This invention relates to air conditioning systems, and more specifically, to an air conditioning system that utilizes a plurality of air conditioning units to exchange heat with air supplied to an indoor space. Background Technology

[0002] Typically, temperature and humidity control devices in air conditioning systems employ a technology that can recover the heat energy emitted to the outside air and reuse it as reheat energy. For example, a portion of the heat dissipation energy generated in the refrigeration cycle can be used as reheat energy to raise the temperature of subcooled air, or a sensible heat exchanger can be used to recover heat by utilizing the temperature difference between the introduced outside air and the exhausted air.

[0003] However, since a portion of the condensation heat is used as reheat energy to raise the temperature of subcooled air, its use is mainly concentrated during the summer rainy season and other times of the year, while its use is greatly reduced during the transitional season.

[0004] In addition, to cope with the large heating load caused by the introduction of outside air in winter, it is necessary to switch to heating cycle operation. When using sensible heat exchangers, the heat recovery is limited because the heat exchange is mainly sensible heat, which may reduce the heat recovery effect during the transition season, or even increase the sensible heat load.

[0005] Korean patent KR10-1206278B1 discloses an outdoor unit capable of switching between cooling and heating operation. Additionally, it discloses an air conditioning system comprising a main coil that can operate as either an evaporator or a condenser, a hot gas reheat coil that can only operate as a condenser, an auxiliary heater, a humidifier, and an air supply mechanism.

[0006] In the aforementioned existing literature, reheating operation using hot gas refrigerant is only possible when the air outlet temperature is overcooled during cooling operation via the main coil. Furthermore, there is a problem that when the cooling system is underloaded, it is difficult to increase cooling and dehumidification capacity at the points when additional cooling and dehumidification are needed.

[0007] Additionally, during the transitional season, there is a problem where the hot air reheat coil stops operating when the air outlet temperature is extremely low. Furthermore, during winter heating operation, there is a risk of a sharp drop in supply air temperature when defrosting or oil recovery is performed. Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The purpose of this invention is to provide an air conditioning system that improves circulation efficiency.

[0010] Another object of the present invention is to provide an air conditioning system that can stably maintain the temperature and humidity of the air supplied to the room even when the outside air temperature is low.

[0011] Another object of the present invention is to provide an air conditioning system that utilizes a heat source discharged to the outside during winter.

[0012] The purpose of this invention is not limited to the purposes mentioned above, and those skilled in the art will clearly understand other purposes not mentioned from the following description.

[0013] Technical solutions to the problem

[0014] To address the aforementioned problems, the air conditioning system of this invention includes: a first duct for conveying air flowing from an outdoor space to an indoor space, wherein a plurality of heat exchangers are arranged inside the first duct; and a second duct for conveying air discharged from the indoor space to the outdoor space.

[0015] The air conditioning system includes: a first air conditioning unit that supplies refrigerant to a first upstream heat exchanger arranged in the first pipe and a second pipe heat exchanger arranged in the second pipe; and a second air conditioning unit that supplies refrigerant to at least one first downstream heat exchanger arranged in the first pipe.

[0016] The first air conditioning unit includes: a first outdoor unit, including a first compressor that supplies refrigerant to the first upstream heat exchanger or the second duct heat exchanger, and a first outdoor heat exchanger that allows refrigerant flowing from the first compressor to exchange heat with air; and a first heat recovery kit that allows refrigerant flowing from or to the first outdoor unit to exchange heat with refrigerant flowing to the first compressor.

[0017] The first heat recovery kit includes a first internal heat exchanger. The first internal heat exchanger allows refrigerant flowing from or to the first outdoor heat exchanger to exchange heat with refrigerant flowing to the first compressor.

[0018] The first heat recovery kit includes a first internal switching valve that delivers refrigerant flowing from the first compressor to the first upstream heat exchanger or the second pipeline heat exchanger.

[0019] The air conditioning system also includes a bypass pipe connecting the first pipe and the second pipe. A bypass valve is provided on the bypass pipe to connect or disconnect the first pipe and the second pipe.

[0020] The bypass pipe is located upstream of the second pipe heat exchanger.

[0021] The bypass pipe supplies air flowing from the second pipe to the first upstream heat exchanger.

[0022] The second air conditioning unit includes a second outdoor unit, the second outdoor unit including: a second compressor for supplying refrigerant to at least one first downstream heat exchanger; and a second outdoor heat exchanger for exchanging heat between the refrigerant flowing from the second compressor and air.

[0023] The second air conditioning unit includes a second heat recovery kit, which allows refrigerant flowing from or to the second outdoor unit to exchange heat with refrigerant flowing to the second compressor.

[0024] The second heat recovery kit includes a second internal heat exchanger that allows refrigerant flowing from or to the second outdoor heat exchanger to exchange heat with refrigerant flowing to the second compressor.

[0025] The first downstream heat exchanger includes: a first-1 downstream heat exchanger disposed downstream of the first upstream heat exchanger; and a first-2 downstream heat exchanger disposed downstream of the first-1 downstream heat exchanger.

[0026] Either the first-1 downstream heat exchanger or the first-2 downstream heat exchanger supplies refrigerant to the second outdoor unit through the second internal heat exchanger.

[0027] The heat transfer area of ​​the first-1 downstream heat exchanger is greater than that of the first-2 downstream heat exchanger.

[0028] The second air conditioning unit includes: a second outdoor unit, including a second compressor and a second outdoor heat exchanger; and a second heat recovery kit, which allows refrigerant flowing out of or into the second outdoor unit to exchange heat with refrigerant flowing into the second compressor.

[0029] The second heat recovery kit includes a second internal switching valve that supplies refrigerant flowing from the second compressor to either the first-1 downstream heat exchanger or the first-2 downstream heat exchanger.

[0030] The second internal switching valve delivers refrigerant flowing from the other of the first-1 downstream heat exchanger and the first-2 downstream heat exchanger to the second internal heat exchanger.

[0031] The second air conditioning unit includes: a second outdoor unit, including a second compressor and a second outdoor heat exchanger for exchanging heat between refrigerant flowing from the second compressor and air; and a second heat recovery kit for exchanging heat between refrigerant flowing from or to the second outdoor unit and refrigerant flowing to the second compressor.

[0032] Specific details regarding other embodiments are included in the detailed description and accompanying drawings.

[0033] Invention Effects

[0034] The air conditioning system according to the present invention has one or more of the following effects.

[0035] First, the heat recovery kit allows the heat generated during operation to be reused to raise the temperature of the subcooled air, just as before. Furthermore, even in extreme heat where it is difficult to dissipate heat to the hot outside air, heat can be dissipated to the relatively cooler exhaust air, thus preventing a decrease in cooling and dehumidification capacity and improving circulation efficiency.

[0036] Secondly, by arranging and matching the sizes of the plurality of heat exchangers installed in the first pipe, even in extreme cold conditions where the outside air temperature is low and the heat absorption is reduced, heat can still be absorbed from the relatively high-temperature exhaust air side, thereby preventing a decrease in heating capacity and improving circulation efficiency.

[0037] Third, during winter heating, utilizing the heat source of exhaust air at a temperature higher than the outside air temperature ensures additional evaporative heat, thereby improving heating capacity and efficiency. Furthermore, the increased evaporation temperature slows down the frosting process, minimizing the frequency of defrosting operations. During defrosting and oil recovery operations, continuous heating minimizes the drop in outlet air temperature, and the increased evaporation temperature expands the range of frost-free operation.

[0038] Fourth, even if the design capacity of the gas supply side heat exchanger is small, the heat recovery kit can be used to enable the first upstream heat exchanger located in the first pipeline to operate in heating mode, thereby providing sufficient heating capacity.

[0039] The effects of the present invention are not limited to those mentioned above, and those skilled in the art can more clearly understand other effects not mentioned through the description in the appended claims. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of an air conditioning system according to an embodiment of the present invention.

[0041] Figure 2 This is a detailed system diagram of an air conditioning system according to an embodiment of the present invention.

[0042] Figure 3 This is a diagram illustrating the flow of refrigerant in an air conditioning system according to an embodiment of the present invention during summer.

[0043] Figure 4 This is a diagram illustrating the flow of refrigerant in an air conditioning system according to an embodiment of the present invention during a normal winter.

[0044] Figure 5 This is a diagram illustrating the flow of refrigerant in an air conditioning system during defrosting winter according to an embodiment of the present invention.

[0045] Figure 6 This is a diagram illustrating the flow of refrigerant in an air conditioning system according to an embodiment of the present invention during extremely low temperature winters.

[0046] Figure 7 This is a diagram illustrating the refrigerant flow in an air conditioning system according to an embodiment of the present invention during the transition season.

[0047] Figure 8 This is a schematic diagram of an air conditioning system according to an embodiment of the present invention. Detailed Implementation

[0048] The advantages and features of the present invention, as well as methods of implementing them, will become apparent from the embodiments described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms. These embodiments are provided only to more fully disclose the invention and to more completely indicate the scope of the invention to those skilled in the art. The invention is defined only by the scope of the claims. Throughout this specification, the same reference numerals denote the same constituent elements.

[0049] Terms containing ordinal numbers such as "first" and "second" may be used to describe a variety of constituent elements, but the constituent elements are not limited by the terms. The terms are used only for the purpose of distinguishing one constituent element from other constituent elements.

[0050] Hereinafter, an air conditioning system according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0051] Reference Figure 1 The entire air conditioning system of the present invention will be described.

[0052] The air conditioning system includes a first duct 300 for supplying air from outdoor space to indoor space. A plurality of heat exchangers are arranged in the first duct 300. A first fan 302 for supplying air to the indoor space may be arranged in the first duct 300.

[0053] A first upstream heat exchanger 140 of a first air conditioning unit 100, which will be described later, may be arranged in the first conduit 300. A first downstream heat exchanger 240, 242 of a second air conditioning unit 200, which will be described later, may be arranged in the first conduit 300.

[0054] The first downstream heat exchangers 240 and 242 may include a first-1 downstream heat exchanger 240 and a first-2 downstream heat exchanger 242 disposed downstream of the first-1 downstream heat exchanger 240. The first duct 300 may be provided with the first-1 downstream heat exchanger 240 and the first-2 downstream heat exchanger 242 of the second air conditioning unit 200, which will be described later.

[0055] The air flowing in the first pipe 300 can flow sequentially through the first upstream heat exchanger 140 and the first downstream heat exchangers 240 and 242.

[0056] The air flowing in the first pipe 300 can flow sequentially through the first upstream heat exchanger 140, the first downstream heat exchanger 240, and the first downstream heat exchanger 242.

[0057] The air conditioning system includes a second duct 310 that delivers air from the indoor space to the outdoor space.

[0058] At least one heat exchanger may be arranged in the second duct 310. A second fan 312 may be arranged in the second duct 310 to exhaust air to the outside space. A second fan 312 may be arranged in the second duct 310 to exhaust air from the indoor space to the outside space.

[0059] A second duct heat exchanger 142 of the first air conditioning unit 100 may be arranged in the second duct 310. The air flowing in the second duct 310 can be discharged to the outside space through the second duct heat exchanger 142 by the second fan 312.

[0060] The air conditioning system includes a bypass pipe 320 that connects the first pipe 300 and the second pipe 310.

[0061] Air flowing in the second pipe 310 can flow to the first pipe 300 through the bypass pipe 320. The bypass pipe 320 is connected to the second pipe 310 in the upstream region of the second pipe heat exchanger 142. The bypass pipe 320 is connected to the first pipe 300 in a region further upstream than the first upstream heat exchanger 140.

[0062] That is, air flowing from the indoor space into the second pipe 310 can flow to the upstream end of the first pipe 300 through the bypass pipe 320. The air flowing to the first pipe 300 through the bypass pipe 320 can be air that does not undergo heat exchange inside the second pipe 310.

[0063] A first bypass valve 322 is arranged inside the bypass pipe 320 to open and close the internal flow path of the bypass pipe 320.

[0064] The air conditioning system includes a first air conditioning unit 100, which utilizes a first compressor 112 (see reference). Figure 2 The system operates to supply refrigerant to a plurality of heat exchangers arranged in the first pipe 300 and the second pipe 310.

[0065] The first air conditioning unit 100 includes a first upstream heat exchanger 140 arranged in the first duct 300.

[0066] The first air conditioning unit 100 includes a second pipe heat exchanger 142 arranged in the second pipe 310.

[0067] The air conditioning system includes a second air conditioning unit 200, which utilizes a second compressor 212 (see reference). Figure 2 The system operates to supply refrigerant to a plurality of heat exchangers arranged in the first pipe 300 and the third pipe 420.

[0068] The second air conditioning unit 200 includes a first-1 downstream heat exchanger 240 and a first-2 downstream heat exchanger 242 arranged in the first duct 300.

[0069] The first-1 downstream heat exchanger 240 and the first-2 downstream heat exchanger 242 are respectively arranged inside the first pipe 300 downstream of the first upstream heat exchanger 140. Therefore, the air passing through the first upstream heat exchanger 140 flows to the first-1 downstream heat exchanger 240 and the first-2 downstream heat exchanger 242, respectively.

[0070] The first-second downstream heat exchanger 242 is positioned closer to the outlet side of the first duct 300 than the first-first downstream heat exchanger 240. Therefore, air flowing in through the intake of the first duct 300 can pass through the first-second downstream heat exchanger 242 in sequence.

[0071] Reference Figure 2 The specific configuration of the first air conditioning unit 100 and the second air conditioning unit 200, as well as their connection relationship with the first pipe 300 and the second pipe 310, will be explained.

[0072] The first air conditioning unit 100 includes a first outdoor unit 110 with a first compressor 112 and a first outdoor heat exchanger 114 arranged thereon, and a first heat recovery kit 130 for exchanging heat between refrigerant flowing out of the first outdoor unit 110 and refrigerant flowing toward the first outdoor unit 110 or for changing the flow direction of the refrigerant.

[0073] The first air conditioning unit 100 includes a first upstream heat exchanger 140 arranged in a first duct 300 and a second duct heat exchanger 142 arranged in a second duct 310.

[0074] The first outdoor unit 110 includes a first compressor 112. The first outdoor unit 110 includes a first outdoor heat exchanger 114 that allows refrigerant flowing from the first compressor 112 to exchange heat with outdoor air.

[0075] The first outdoor unit 110 includes a first receiver 122 that supplies gaseous refrigerant to the first compressor 112. The first outdoor unit 110 includes first switching valves 118, 120 that supply refrigerant flowing from the first compressor 112 to the first outdoor heat exchanger 114 or to the outside of the first outdoor unit 110.

[0076] The first outdoor unit 110 includes a first-1 switching valve 118 that supplies refrigerant flowing from the first compressor 112 to the first outdoor heat exchanger 114 or supplies refrigerant flowing from the first outdoor heat exchanger 114 to the first compressor 112. The first outdoor unit 110 also includes a first-2 switching valve 120 that supplies refrigerant flowing from the first compressor 112 to the outside of the first outdoor unit 110.

[0077] The first outdoor unit 110 includes a first outdoor expansion valve 116 that expands refrigerant flowing out of or into the first outdoor heat exchanger 114.

[0078] The first outdoor expansion valve 116 can expand the liquid refrigerant flowing into the first outdoor heat exchanger 114. The first outdoor expansion valve 116 can also expand the liquid refrigerant flowing out of the first outdoor heat exchanger 114.

[0079] The first heat recovery kit 130 includes a first internal heat exchanger 132 that allows refrigerant flowing to the outside of the first outdoor unit 110 to exchange heat with refrigerant flowing to the inside of the first outdoor unit 110.

[0080] The first heat recovery kit 130 includes a first internal switching valve 134 that supplies refrigerant discharged from the first outdoor unit 110 to the second duct heat exchanger 142 or the first upstream heat exchanger 140.

[0081] The first internal switching valve 134 can deliver high-pressure refrigerant discharged from the first compressor 112 to the second pipe heat exchanger 142. Additionally, the first internal switching valve 134 can deliver high-pressure refrigerant discharged from the first compressor 112 to the first upstream heat exchanger 140.

[0082] The first air conditioning unit 100 includes first expansion valves 150 and 152 for expanding refrigerant flowing through a heat exchanger arranged in a first conduit 300 or a second conduit 310. The first air conditioning unit 100 includes a first-1 expansion valve 150 for expanding refrigerant flowing towards a first upstream heat exchanger 140. The first air conditioning unit 100 includes a first-3 expansion valve 152 for expanding refrigerant flowing towards a second conduit heat exchanger 142.

[0083] The second air conditioning unit 200 includes a second outdoor unit 210 with a second compressor 212 and a second outdoor heat exchanger 214 arranged thereon, and a second heat recovery kit 230 that allows the refrigerant flowing out of the second outdoor unit 210 to exchange heat with the refrigerant flowing toward the second outdoor unit 210 or to change the flow direction of the refrigerant.

[0084] The second air conditioning unit 200 includes a first-second pipe heat exchanger 140 and a first-third pipe heat exchanger 142 arranged in the first pipe 300.

[0085] The second outdoor unit 210 includes a second compressor 212. The second outdoor unit 210 includes a second outdoor heat exchanger 214 that allows refrigerant flowing from the second compressor 212 to exchange heat with outdoor air.

[0086] The second outdoor unit 210 includes a second receiver 222 that supplies gaseous refrigerant to the second compressor 212. The second outdoor unit 210 also includes second switching valves 218 and 220 that deliver refrigerant flowing from the second compressor 212 to the second outdoor heat exchanger 214 or to the outside of the second outdoor unit 210.

[0087] The second outdoor unit 210 includes a second-1 switching valve 218 that supplies refrigerant from the second compressor 212 to the second outdoor heat exchanger 214 or supplies refrigerant from the second outdoor heat exchanger 214 to the second compressor 212. The second outdoor unit 210 also includes a second-2 switching valve 220 that supplies refrigerant from the second compressor 212 to the outside of the second outdoor unit 210.

[0088] The second outdoor unit 210 includes a second outdoor expansion valve 216 that expands the refrigerant flowing out of or into the second outdoor heat exchanger 214.

[0089] The second outdoor expansion valve 216 can expand the liquid refrigerant flowing into the second outdoor heat exchanger 214. The second outdoor expansion valve 216 can also expand the liquid refrigerant flowing out of the second outdoor heat exchanger 214.

[0090] The second heat recovery kit 230 includes a second internal heat exchanger 232 that allows refrigerant flowing to the outside of the second outdoor unit 210 to exchange heat with refrigerant flowing from the outside of the second outdoor unit 210 to the second compressor 212.

[0091] The second internal heat exchanger 232 allows liquid refrigerant flowing out of or into the second outdoor heat exchanger 214 to exchange heat with refrigerant flowing from the outside of the second outdoor unit 210 into the second compressor 212 of the second outdoor unit 210.

[0092] The second heat recovery kit 230 includes a second internal switching valve 234 that supplies refrigerant discharged from the second outdoor unit 210 to either the first-1 downstream heat exchanger 240 or the first-2 downstream heat exchanger 242. The second internal switching valve 234 can supply high-pressure refrigerant discharged from the second compressor 212 to either the first-1 downstream heat exchanger 240 or the first-2 downstream heat exchanger 242.

[0093] The second air conditioning unit 200 includes a second expansion valve 250, 252 that expands refrigerant flowing through a heat exchanger arranged in the first conduit 300.

[0094] The second air conditioning unit 200 includes a second-1 expansion valve 250 that expands the refrigerant flowing to the first-1 downstream heat exchanger 240. The second air conditioning unit 200 also includes a second-2 expansion valve 252 that expands the refrigerant flowing to the first-2 downstream heat exchanger 242.

[0095] The capacity of the first-1 downstream heat exchanger 240 can be greater than the capacity of the first-2 downstream heat exchanger 242. That is, the heat transfer area of ​​the first-1 downstream heat exchanger 240 can be greater than the heat transfer area of ​​the first-2 downstream heat exchanger 242.

[0096] The following is for reference Figure 3 The operation of the air conditioning system of the present invention during summer will be described.

[0097] First, using pipelines as a reference, we will explain the operation of multiple heat exchangers.

[0098] In summer, outdoor air can be hot and humid. Outdoor temperatures can reach over 28 degrees Celsius.

[0099] The first pipe 300 introduces air from the outdoor space and supplies air to the indoor space.

[0100] The first upstream heat exchanger 140 and the first downstream heat exchanger 240 arranged in the first pipe 300 both operate as evaporators. The first downstream heat exchanger 242 arranged in the first pipe 300 operates as a condenser.

[0101] The air flowing in the first pipe 300 can pass through the first upstream heat exchanger 140 and the first downstream heat exchanger 240 in sequence and be cooled. That is, the air flowing into the first pipe 300 can pass through the first upstream heat exchanger 140 and the first downstream heat exchanger 240 in sequence and remove moisture for the first time.

[0102] The air flowing in the first pipe 300 can pass through the first-second downstream heat exchanger 242 and its temperature rises.

[0103] The air flowing inside the first duct 300 can be converted to a low-humidity state and supplied to the indoor space. In summer, humid air from the outdoor space can be reduced in humidity as it passes through the first duct 300 before being supplied to the indoor space.

[0104] Air from the indoor space flows into the second duct 310. The second duct 310 can exhaust air to the outdoor space.

[0105] The second pipe heat exchanger 142, arranged in the second pipe 310, operates as a condenser.

[0106] The air flowing in the second pipe 310 can be discharged to the outdoor space after passing through the second pipe heat exchanger 142 and being heated.

[0107] The flow of refrigerant in the first air conditioning unit 100 and the second air conditioning unit 200 will be described below.

[0108] The flow of refrigerant flowing in the first air conditioning unit 100 will be described.

[0109] A portion of the refrigerant discharged from the first compressor 112 flows to the first outdoor heat exchanger 114. The first outdoor heat exchanger 114 can operate as a condenser.

[0110] Another portion of the refrigerant discharged from the first compressor 112 can flow to the second pipe heat exchanger 142 via the first-second switching valve 120 and the first internal switching valve 134. Therefore, the second pipe heat exchanger 142 can operate as a condenser.

[0111] The refrigerant flowing through the first outdoor heat exchanger 114 can flow to the first upstream heat exchanger 140. At this time, the refrigerant flowing out of the first outdoor heat exchanger 114 passes through the first internal heat exchanger 132, which can increase the liquid-to-liquid ratio of the refrigerant.

[0112] In addition, the refrigerant flowing out of the second pipe heat exchanger 142 can also flow to the first upstream heat exchanger 140.

[0113] The first upstream heat exchanger 140 can operate as an evaporator.

[0114] The refrigerant flowing out from the first upstream heat exchanger 140 can flow to the first compressor 112 via the first internal heat exchanger 132.

[0115] The ratio of refrigerant discharged from the first compressor 112 and flowing into the first outdoor heat exchanger 114 is adjusted to 20% or less. In addition, the ratio of refrigerant discharged from the first compressor 112 and flowing into the second pipe heat exchanger 142 is adjusted to 80% or more.

[0116] That is, the flow rate of refrigerant supplied from the first compressor 112 to the first outdoor heat exchanger 114 and the second pipeline heat exchanger 142 can be adjusted by adjusting the first outdoor expansion valve 116 and the first-second expansion valve 152.

[0117] The flow of refrigerant flowing in the second air conditioning unit 200 will be described.

[0118] A portion of the refrigerant discharged from the second compressor 212 flows to the second outdoor heat exchanger 214. The second outdoor heat exchanger 214 can operate as a condenser.

[0119] Another portion of the refrigerant discharged from the second compressor 212 can flow to the first-second downstream heat exchanger 242 via the second-second switching valve 220 and the second internal switching valve 234.

[0120] The refrigerant flowing out of the second outdoor heat exchanger 214 can flow to the first downstream heat exchanger 240 via the second internal heat exchanger 232. The refrigerant flowing out of the second outdoor heat exchanger 214 can increase the ratio of liquid refrigerant by passing through the second internal heat exchanger 232.

[0121] The refrigerant discharged from the first-second downstream heat exchanger 242 can also flow to the first-first downstream heat exchanger 240.

[0122] The first-1 downstream heat exchanger 240 can operate as an evaporator. The refrigerant flowing out of the first-1 downstream heat exchanger 240 can flow to the second compressor 212 via the second internal heat exchanger 232.

[0123] It can be adjusted to reduce the flow rate of refrigerant flowing to the second outdoor heat exchanger 214.

[0124] The ratio of refrigerant discharged from the second compressor 212 and flowing into the second outdoor heat exchanger 214 is adjusted to 20% or less. In addition, the ratio of refrigerant discharged from the second compressor 212 and flowing into the first-second downstream heat exchanger 242 is adjusted to 80% or more.

[0125] That is, the flow rate of refrigerant supplied from the second compressor 212 to the second outdoor heat exchanger 214 and the first-second downstream heat exchanger 242 can be adjusted by adjusting the second outdoor expansion valve 216 and the second-second expansion valve 252.

[0126] The following is for reference Figure 4 The operation of the air conditioning system of the present invention during normal winter will be described.

[0127] In a typical winter, outdoor air can be cold and dry. The temperature can be below 18 degrees Celsius. However, the temperature can also be above 4 degrees Celsius.

[0128] First, using pipelines as a reference, we will explain the operation of multiple heat exchangers.

[0129] The first pipe 300 introduces air from the outdoor space and supplies air to the indoor space.

[0130] The first upstream heat exchanger 140 arranged in the first pipe 300 can operate as a condenser.

[0131] The heat exchanger 242 located in the first pipe 300, from pipe 1 to 3, can operate as a condenser or be deactivated. The heat exchanger 240 located downstream of the first pipe 300, from pipe 1 to 1, can operate as an evaporator or be deactivated.

[0132] The air flowing in the first pipe 300 can pass through the first upstream heat exchanger 140 and be heated.

[0133] The air flowing in the first pipe 300 can be partially cooled and then reheated after passing through the first-1 downstream heat exchanger 240 and the first-2 downstream heat exchanger 242. In addition, when the first-1 downstream heat exchanger 240 and the first-2 downstream heat exchanger 242 are stopped, heat exchange only occurs in the first upstream heat exchanger 140.

[0134] A portion of the air flowing inside the first duct 300 can be heated and supplied to the indoor space.

[0135] In addition, during a typical winter, the cold air flowing in from the outdoor space can flow through the first duct 300 and be supplied to the indoor space in a warmed state.

[0136] Air from the indoor space flows into the second duct 310. The second duct 310 can exhaust air to the outdoor space.

[0137] The second pipe heat exchanger 142 arranged in the second pipe 310 can operate as an evaporator.

[0138] The air flowing in the second pipe 310 can be discharged to the outdoor space after passing through the second pipe heat exchanger 142 and being cooled.

[0139] The flow of refrigerant in the first air conditioning unit 100 and the second air conditioning unit 200 will be described below.

[0140] The flow of refrigerant flowing in the first air conditioning unit 100 will be described.

[0141] The refrigerant discharged from the first compressor 112 can flow to the first upstream heat exchanger 140 via the first-second switching valve 120 and the first internal switching valve 134. The first upstream heat exchanger 140 can operate as a condenser.

[0142] A portion of the refrigerant flowing out of the first upstream heat exchanger 140 flows to the second pipe heat exchanger 142. The second pipe heat exchanger 142 can operate as an evaporator.

[0143] The refrigerant flowing out from the second pipe heat exchanger 142 can flow to the first compressor 112 via the first internal heat exchanger 132.

[0144] Another portion of the refrigerant flowing out from the first upstream heat exchanger 140 can flow to the first outdoor heat exchanger 114 via the first internal heat exchanger 132.

[0145] The gaseous refrigerant flowing from the second pipe heat exchanger 142 to the first compressor 112 and the liquid refrigerant flowing from the first upstream heat exchanger 140 to the first outdoor heat exchanger 114 can exchange heat in the first internal heat exchanger 132. This can increase the proportion of liquid refrigerant in the refrigerant flowing to the first outdoor heat exchanger 114.

[0146] The first outdoor heat exchanger 114 can operate as an evaporator. The refrigerant flowing out of the first outdoor heat exchanger 114 can flow to the first compressor 112.

[0147] The liquid refrigerant flowing from the first upstream heat exchanger 140 is diverted to the first outdoor heat exchanger 114 and the second pipe heat exchanger 142. Furthermore, the flow rate of refrigerant flowing to the first outdoor heat exchanger 114 can be adjusted by regulating the first outdoor expansion valve 116 and the first-second expansion valves 152. That is, by adjusting the amount of refrigerant flowing to the first outdoor heat exchanger 114 to be relatively small, frost formation on the first outdoor heat exchanger 114 can be prevented.

[0148] The flow of refrigerant flowing in the second air conditioning unit 200 will be described.

[0149] The second air conditioning unit 200 can stop the operation of the second compressor 212.

[0150] However, the second compressor 212 can be operated when the heating supply capacity of the first air conditioning unit 100 is insufficient. Whether the heating supply capacity of the first air conditioning unit 100 is insufficient can be determined based on the temperature of the air supplied to the indoor space through the first pipe 300. That is, the second compressor 212 can be operated when the temperature of the air supplied to the indoor space through the first pipe 300 is lower than the set temperature.

[0151] The flow of refrigerant in the second air conditioning unit 200 under the condition that the second compressor 212 is operating will be described below.

[0152] The refrigerant discharged from the second compressor 212 can flow to the first-second downstream heat exchanger 242 via the second-second switching valve 220 and the second internal switching valve 234.

[0153] A portion of the refrigerant discharged from the first-second downstream heat exchanger 242 flows to the second outdoor heat exchanger 214 via the second internal heat exchanger 232. By passing through the second internal heat exchanger 232, the proportion of liquid refrigerant in the refrigerant flowing to the second outdoor heat exchanger 214 can be increased.

[0154] The second outdoor heat exchanger 214 can operate as an evaporator. The refrigerant flowing out of the second outdoor heat exchanger 214 can flow to the second compressor 212.

[0155] Another portion of the refrigerant discharged from the first-second downstream heat exchanger 242 can flow to the first-first downstream heat exchanger 240. The first-first downstream heat exchanger 240 can operate as an evaporator.

[0156] The refrigerant flowing out from the downstream heat exchanger 240 of the first-1 can flow to the second compressor 212 via the second internal heat exchanger 232.

[0157] The heat transfer area of ​​the first-1 downstream heat exchanger 240 can be larger than that of the first-2 downstream heat exchanger 242. Therefore, when only the first-2 downstream heat exchanger 242 is used as a condenser, the refrigerant flow rate can be relatively reduced.

[0158] In addition, since the refrigerant flowing out from the first-1 downstream heat exchanger 240 is diverted and flows to the first-1 downstream heat exchanger 240 and the second outdoor heat exchanger 214, the flow rate of the refrigerant flowing to the second outdoor heat exchanger 214 can be smaller.

[0159] Alternatively, the flow rate of refrigerant flowing to the second outdoor heat exchanger 214 can be reduced by adjusting the second-2 expansion valve 252 and the second outdoor expansion valve 216.

[0160] The following is for reference Figure 5 The operation of the air conditioning system of the present invention during defrosting winter conditions will be described.

[0161] Defrosting winter refers to a condition where the outdoor temperature is below 4 degrees Celsius and above -2 degrees Celsius. Defrosting winter also refers to the temperature conditions under which the condensate produced may easily freeze when the first outdoor heat exchanger 114 or the second outdoor heat exchanger 214, which exchanges heat with the outdoor air, operates as an evaporator.

[0162] During the defrosting winter, the air in outdoor spaces can be in a state of low temperature and low humidity.

[0163] Therefore, the air supplied to the indoor space through the first duct 300 does not require an additional dehumidification process. However, since the air flowing into the first duct 300 is at a low temperature, it can be heated before being supplied to the indoor space.

[0164] First, using pipelines as a reference, we will explain the operation of multiple heat exchangers.

[0165] The first upstream heat exchanger 140, the first-1 downstream heat exchanger 240, and the first-2 downstream heat exchanger 242, all arranged inside the first pipe 300, can be used as follows: Figure 4 It operates as described herein. That is, the first upstream heat exchanger 140 can operate as a condenser.

[0166] Downstream heat exchanger 240 (1-1) can be stopped or operated as an evaporator. Downstream heat exchanger 242 (1-2) can be stopped or operated as a condenser.

[0167] The second pipe heat exchanger 142 arranged in the second pipe 310 can also be as follows Figure 4 It operates as described herein. That is, the second pipe heat exchanger 142 can operate as an evaporator.

[0168] The flow of refrigerant in the first air conditioning unit 100 and the second air conditioning unit 200 will be described below.

[0169] The flow of refrigerant flowing in the first air conditioning unit 100 will be described.

[0170] The flow of refrigerant in the first air conditioning unit 100 can be combined with... Figure 4 The refrigerant flow in the first air conditioning unit 100 described herein is the same.

[0171] The amount of refrigerant flowing to the first outdoor heat exchanger 114 can be adjusted to be relatively small. That is, the amount of refrigerant flowing to the first outdoor heat exchanger 114 can be maintained at 20 to 30% of the amount of refrigerant flowing out of the first upstream heat exchanger 140.

[0172] By adjusting the first outdoor expansion valve 116 and the first-second expansion valve 152, the flow rate of refrigerant supplied from the first upstream heat exchanger 140 to the first outdoor heat exchanger 114 and the second pipeline heat exchanger 142 can be regulated. That is, the flow rate of refrigerant flowing to the first outdoor heat exchanger 114 can be regulated by adjusting the first outdoor expansion valve 116 and the first-second expansion valve 152.

[0173] Therefore, by minimizing the amount of refrigerant flowing to the first outdoor heat exchanger 114, the rate of frost formation in the first outdoor heat exchanger 114 can be slowed down.

[0174] The flow of refrigerant flowing in the second air conditioning unit 200 will be described.

[0175] The second air conditioning unit 200 can stop the operation of the second compressor 212.

[0176] However, the second compressor 212 can be operated when the heating supply capacity of the first air conditioning unit 100 is insufficient. Whether the heating supply capacity of the first air conditioning unit 100 is insufficient can be determined based on the temperature of the air supplied to the indoor space through the first pipe 300. That is, the second compressor 212 can be operated when the temperature of the air supplied to the indoor space through the first pipe 300 is lower than the set temperature.

[0177] During the operation of the second air conditioning unit 200, the flow of refrigerant and Figure 4 The refrigerant flow of the second air conditioning unit 200 described herein is the same.

[0178] When the second air conditioning unit 200 is in operation, it can be adjusted to reduce the flow rate of refrigerant flowing to the second outdoor heat exchanger 214.

[0179] The heat transfer area of ​​the first-1 downstream heat exchanger 240 can be larger than that of the first-2 downstream heat exchanger 242. Therefore, when only the first-2 downstream heat exchanger 242 is used as a condenser, the refrigerant flow rate can be relatively reduced.

[0180] In addition, since the refrigerant flowing out from the first-1 downstream heat exchanger 240 is diverted and flows to the first-1 downstream heat exchanger 240 and the second outdoor heat exchanger 214, the flow rate of the refrigerant flowing to the second outdoor heat exchanger 214 can be smaller.

[0181] Alternatively, the flow rate of refrigerant flowing to the second outdoor heat exchanger 214 can be reduced by adjusting the second-2 expansion valve 252 and the second outdoor expansion valve 216.

[0182] Therefore, even if the second air conditioning unit 200 is running, it can delay the frost formation in the second outdoor heat exchanger 214 to the greatest extent possible.

[0183] The following is for reference Figure 6 The operation of the air conditioning system of the present invention during extremely low temperature winters will be described.

[0184] Extremely low temperatures in winter can refer to outdoor temperatures below -2 degrees Celsius. In extremely low temperatures, even if the outdoor heat exchanger is used as an evaporator, frost formation may not occur.

[0185] In extremely cold winters, the air in outdoor spaces can be in a state of low temperature and low humidity.

[0186] Since the air flowing into the first pipe 300 is at an extremely low temperature, it can be heated and supplied to the indoor space.

[0187] First, using pipelines as a reference, we will explain the operation of multiple heat exchangers.

[0188] The first upstream heat exchanger 140, located inside the first pipe 300, can operate as a condenser.

[0189] The first downstream heat exchanger 240, located inside the first pipe 300, can operate as a condenser. The first downstream heat exchanger 242, located inside the first pipe 300, can operate as an evaporator.

[0190] That is, by operating the first-1 downstream heat exchanger 240, which has a relatively large heat transfer area, as a condenser, and the first-2 downstream heat exchanger 242, which has a relatively small heat transfer area, as an evaporator, the heating performance can be improved.

[0191] The second pipe heat exchanger 142 arranged in the second pipe 310 can also be as follows Figure 4 It operates as described herein. That is, the second pipe heat exchanger 142 can operate as an evaporator.

[0192] The flow of refrigerant in the first air conditioning unit 100 and the second air conditioning unit 200 will be described below.

[0193] The flow of refrigerant flowing in the first air conditioning unit 100 will be described.

[0194] The flow of refrigerant in the first air conditioning unit 100 can be combined with... Figure 4The refrigerant flow in the first air conditioning unit 100 described herein is the same.

[0195] The amount of refrigerant flowing to the first outdoor heat exchanger 114 can be adjusted to be relatively small. That is, the amount of refrigerant flowing to the first outdoor heat exchanger 114 can be maintained at 20 to 30% of the amount of refrigerant flowing out of the first upstream heat exchanger 140.

[0196] By adjusting the first outdoor expansion valve 116 and the first-second expansion valve 152, the flow rate of refrigerant supplied from the first upstream heat exchanger 140 to the first outdoor heat exchanger 114 and the second pipeline heat exchanger 142 can be regulated. That is, the flow rate of refrigerant flowing to the first outdoor heat exchanger 114 can be regulated by adjusting the first outdoor expansion valve 116 and the first-second expansion valve 152.

[0197] The flow of refrigerant flowing in the second air conditioning unit 200 will be described.

[0198] The refrigerant discharged from the second compressor 212 can flow to the first-1 downstream heat exchanger 240 via the second-2 switching valve 220 and the second internal switching valve 234. The first-1 downstream heat exchanger 240 can operate as a condenser.

[0199] A portion of the refrigerant discharged from the first-1 downstream heat exchanger 240 can flow to the second outdoor heat exchanger 214 via the second internal heat exchanger 232. By passing through the second internal heat exchanger 232, the proportion of liquid refrigerant in the refrigerant flowing to the second outdoor heat exchanger 214 can be increased.

[0200] The second outdoor heat exchanger 214 can operate as an evaporator. The refrigerant flowing out of the second outdoor heat exchanger 214 can flow to the second compressor 212.

[0201] Another portion of the refrigerant discharged from the first downstream heat exchanger 240 can flow to the first downstream heat exchanger 242. The first downstream heat exchanger 242 can operate as an evaporator.

[0202] The refrigerant flowing out from the first-second downstream heat exchanger 242 can flow to the second compressor 212 via the second internal heat exchanger 232.

[0203] The heat transfer area of ​​the first-1 downstream heat exchanger 240 can be larger than that of the first-2 downstream heat exchanger 242. Therefore, when the first-1 downstream heat exchanger 240 is used as a condenser, the refrigerant flow rate can be relatively increased.

[0204] In addition, by using the first downstream heat exchanger 240 as a condenser, the performance of heating the air flowing in the first pipe 300 can be improved.

[0205] In addition, since the refrigerant flowing out of the first-1 downstream heat exchanger 240 is diverted and flows to the first-2 downstream heat exchanger 242 and the second outdoor heat exchanger 214, the flow rates of the refrigerant flowing to the second outdoor heat exchanger 214 and the first-2 downstream heat exchanger 242 can be relatively small.

[0206] Alternatively, the flow rate of refrigerant flowing to the second outdoor heat exchanger 214 can be reduced by adjusting the second-2 expansion valve 252 and the second outdoor expansion valve 216.

[0207] The following is for reference Figure 7 The operation of the air conditioning system of the present invention during the transition season will be described.

[0208] First, using pipelines as a reference, we will explain the operation of multiple heat exchangers.

[0209] During the transitional season, the air in outdoor spaces can be highly humid. The temperature in outdoor spaces can be set between summer and typical winter temperatures.

[0210] First, using pipelines as a reference, we will explain the operation of multiple heat exchangers.

[0211] The first upstream heat exchanger 140, located inside the first pipe 300, can be stopped.

[0212] The first downstream heat exchanger 240, located inside the first pipe 300, can operate as an evaporator. The first downstream heat exchanger 242, located inside the first pipe 300, can operate as a condenser.

[0213] The second pipe heat exchanger 142, which is located in the second pipe 310, can be stopped.

[0214] The flow of refrigerant in the first air conditioning unit 100 and the second air conditioning unit 200 will be described below.

[0215] The flow of refrigerant flowing in the first air conditioning unit 100 will be described.

[0216] The first air conditioning unit 100 can be stopped.

[0217] The flow of refrigerant flowing in the second air conditioning unit 200 will be described.

[0218] During the operation of the second air conditioning unit 200, the flow of refrigerant and Figure 3The refrigerant flow of the second air conditioning unit 200 described herein is the same.

[0219] It can be adjusted to reduce the flow rate of refrigerant flowing to the second outdoor heat exchanger 214.

[0220] The ratio of refrigerant discharged from the second compressor 212 and flowing into the second outdoor heat exchanger 214 is adjusted to 20% or less. In addition, the ratio of refrigerant discharged from the second compressor 212 and flowing into the first-second downstream heat exchanger 242 is adjusted to 80% or more.

[0221] That is, the flow rate of refrigerant supplied from the second compressor 212 to the second outdoor heat exchanger 214 and the first-second downstream heat exchanger 242 can be adjusted by adjusting the second outdoor expansion valve 216 and the second-second expansion valve 252.

[0222] Reference Figure 8 An air conditioning system according to another embodiment of the present invention will be described.

[0223] With Figure 1 The explanation will focus on the differences between the air conditioning systems described in the text. Figure 8 The unexplained components can be understood as related to Figure 1 The content described in the text is the same.

[0224] The air conditioning system includes a first duct 300 for supplying air from the outdoor space to the indoor space. A plurality of heat exchangers are arranged in the first duct 300. A first fan 402 for supplying air to the indoor space may be arranged in the first duct 300.

[0225] The first air conditioning unit 100 heat exchangers may be arranged in parallel on the first duct 300. A plurality of heat exchangers of the second air conditioning unit 200 may be arranged in parallel on the first duct 300.

[0226] The heat exchanger of the first air conditioning unit 100 can be arranged in parallel with the second pipe 310.

[0227] In the first pipeline 300, a pair of heat exchangers 140a and 140b for pipeline 1-1, a pair of heat exchangers 240a and 240b for pipeline 1-2, and a pair of heat exchangers 242a and 242b for pipeline 1-3 are arranged in sequence.

[0228] A pair of heat exchangers 140a and 140b in the first pipe 300 can be arranged side by side inside the first pipe 300. The pair of heat exchangers 140a and 140b in the first pipe 300 can each operate individually or simultaneously.

[0229] A pair of first-second pipe heat exchangers 240a and 240b can be arranged side by side inside the first pipe 300. Each of the first-second pipe heat exchangers 240a and 240b can operate independently or simultaneously.

[0230] A pair of heat exchangers 242a and 242b for the first-third pipe can be arranged side by side inside the first pipe 300. Each of the heat exchangers 242a and 242b for the first-third pipe can operate independently or simultaneously.

[0231] A pair of second-pipe heat exchangers 142a and 142b may be arranged in the second pipe 310. The pair of second-pipe heat exchangers 142a and 142b may be arranged side by side inside the second pipe 310. The pair of second-pipe heat exchangers 142a and 142b may operate individually or simultaneously.

[0232] The temperature conditions of the outdoor space can be taken into account to allow a pair of heat exchangers to operate individually or simultaneously.

[0233] The preferred embodiments of the present invention have been illustrated and described above. However, the present invention is not limited to the specific embodiments described above. It is obvious that various modifications can be made by those skilled in the art without departing from the spirit of the invention as claimed in the claims, and these modifications should not be understood separately from the technical concept or prospect of the present invention.

Claims

1. An air conditioning system, wherein, include: The first duct transports air flowing from the outdoor space to the indoor space, and a plurality of heat exchangers are arranged inside the first duct. The second pipe delivers air exhausted from the indoor space to the outdoor space; A first air conditioning unit supplies refrigerant to a first upstream heat exchanger arranged in the first pipe and a second pipe heat exchanger arranged in the second pipe; as well as The second air conditioning unit supplies refrigerant to at least one first downstream heat exchanger arranged in the first duct; The first air conditioning unit includes: The first outdoor unit includes a first compressor that supplies refrigerant to the first upstream heat exchanger or the second pipe heat exchanger, and a first outdoor heat exchanger that allows the refrigerant flowing out of the first compressor to exchange heat with the air. as well as The first heat recovery kit enables heat exchange between the refrigerant flowing out of or into the first outdoor unit and the refrigerant flowing into the first compressor.

2. The air conditioning system according to claim 1, wherein, The first heat recovery kit includes a first internal heat exchanger; The first internal heat exchanger allows refrigerant flowing from or to the first outdoor heat exchanger to exchange heat with refrigerant flowing to the first compressor.

3. The air conditioning system according to claim 1, wherein, The first heat recovery kit includes a first internal switching valve that delivers refrigerant flowing from the first compressor to the first upstream heat exchanger or the second pipeline heat exchanger.

4. The air conditioning system according to claim 1, wherein, It also includes a bypass pipe connecting the first pipe and the second pipe; A bypass valve is provided in the bypass pipe to connect or block the first pipe and the second pipe.

5. The air conditioning system according to claim 4, wherein, The bypass pipe is located upstream of the second pipe heat exchanger.

6. The air conditioning system according to claim 4, wherein, The bypass pipe will deliver air flowing from the second pipe to the first upstream heat exchanger.

7. The air conditioning system according to claim 1, wherein, The second air conditioning unit includes a second outdoor unit; The second outdoor unit includes: A second compressor supplies refrigerant to at least one of the first downstream heat exchangers; and The second outdoor heat exchanger allows the refrigerant flowing from the second compressor to exchange heat with the air.

8. The air conditioning system according to claim 7, wherein, The second air conditioning unit includes a second heat recovery kit; The second heat recovery kit enables heat exchange between the refrigerant flowing out of or into the second outdoor unit and the refrigerant flowing into the second compressor.

9. The air conditioning system according to claim 8, wherein, The second heat recovery kit includes a second internal heat exchanger that allows refrigerant flowing from or to the second outdoor heat exchanger to exchange heat with refrigerant flowing to the second compressor.

10. The air conditioning system according to claim 1, wherein, The first downstream heat exchanger includes: The first-1 downstream heat exchanger is arranged downstream of the first upstream heat exchanger; and The first-second downstream heat exchanger is located downstream of the first-first downstream heat exchanger.

11. The air conditioning system according to claim 10, wherein, Either the first-1 downstream heat exchanger or the first-2 downstream heat exchanger supplies refrigerant to the second outdoor unit through the second internal heat exchanger.

12. The air conditioning system according to claim 10, wherein, The heat transfer area of ​​the first-1 downstream heat exchanger is greater than that of the first-2 downstream heat exchanger.

13. The air conditioning system according to claim 10, wherein, The second air conditioning unit includes: The second outdoor unit includes a second compressor and a second outdoor heat exchanger; and The second heat recovery kit allows the refrigerant flowing out of or into the second outdoor unit to exchange heat with the refrigerant flowing into the second compressor. The second heat recovery kit includes a second internal switching valve that supplies refrigerant flowing from the second compressor to either the first-1 downstream heat exchanger or the first-2 downstream heat exchanger.

14. The air conditioning system according to claim 13, wherein, The second internal switching valve delivers refrigerant flowing from the other of the first-1 downstream heat exchanger and the first-2 downstream heat exchanger to the second internal heat exchanger.

15. An air conditioning system, wherein, include: The first duct transports air flowing from the outdoor space to the indoor space, and a plurality of heat exchangers are arranged inside the first duct. The second pipe delivers air exhausted from the indoor space to the outdoor space; A first air conditioning unit supplies refrigerant to a first upstream heat exchanger arranged in the first pipe and a second pipe heat exchanger arranged in the second pipe; as well as The second air conditioning unit supplies refrigerant to the first downstream heat exchanger 1-1 and the first downstream heat exchanger 1-2 arranged in the first pipeline; The second air conditioning unit includes: The second outdoor unit includes a second compressor and a second outdoor heat exchanger that allows refrigerant flowing from the second compressor to exchange heat with air. as well as The second heat recovery kit enables heat exchange between the refrigerant flowing out of or into the second outdoor unit and the refrigerant flowing into the second compressor.

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