air conditioning

Abstract

An air conditioning system (100) comprises: a branching unit (10); a plurality of indoor units (50a, 50b, 50c); an outdoor unit (60); a plurality of supply branch lines (51a, 51b, 51c) and a plurality of return branch lines (52a, 52b, 52c); and a supply main line (61) and a return main line (62). In a first heat exchanger (12), heat is exchanged between the refrigerant flowing in a first refrigerant line path (R1) and the heat transfer medium flowing in a first line path (P1). In a second heat exchanger (22), heat is exchanged between the refrigerant flowing in the first refrigerant line path (R1) and the heat transfer medium flowing in a second line path (P2).

Description

TECHNICAL AREA

[0001] The present disclosure relates to an air conditioning system. BACKGROUND ON THE STATE OF THE TECHNOLOGY

[0002] An air conditioning system comprising an outdoor unit, a plurality of indoor units and a branching unit, wherein the outdoor unit and the plurality of indoor units are connected by the branching unit, is conventionally known.

[0003] International Publication No. 2009 / 133640 discloses an air conditioning system in which an outdoor unit and a branching unit are connected by a first expansion line and a second expansion line, and the branching unit and an indoor unit are connected by a third expansion line and a fourth expansion line. The air conditioning system includes an intermediate heat exchanger located in the branching unit.

[0004] In the air conditioning system described in the disclosure above, heat transfer is achieved by circulating refrigerant through the first and second expansion lines in the outdoor unit and the branching unit, and heat transfer is achieved by circulating water through the third and fourth expansion lines in the branching unit and the indoor unit. In the intermediate heat exchanger located in the branching unit, heat is exchanged between the refrigerant and the water, with heat being transferred from the indoor unit to the outdoor unit through the intermediate heat exchanger in the branching unit during cooling operation, and from the outdoor unit to the indoor unit through the intermediate heat exchanger in the branching unit during heating operation.

[0005] In the air conditioning system described in the disclosure above, two lines are used for the connection between the outdoor unit and the branching unit, and for the connection between the branching unit and the indoor unit, thus reducing the cost of the piping material and labor hours. REFERENCE LIST PATENT LITERATURE

[0006] PTL 1: International Publication No. 2009 / 133640 SUMMARY OF THE INVENTIONAL PROBLEM

[0007] However, in the air conditioning system described in the disclosure above, the amount of refrigerant used in the air conditioning system may increase if the first extension line and the second extension line between the outdoor unit and the branching unit are installed over a long distance (e.g. 110 meters).

[0008] Furthermore, the branching unit, the indoor unit, and the outdoor unit may be transported to the installation site on different days. In this case, a test run of the air conditioning system described in the disclosure above can only be performed once the branching unit, the indoor unit, and the outdoor unit are all operational.

[0009] The present disclosure was made in light of the problems described above, and one of its aims is to provide an air conditioning system in which the amount of refrigerant used can be reduced and a test run can be carried out with a branching unit and an indoor unit. SOLUTION TO THE PROBLEM

[0010] An air conditioning system according to the present disclosure comprises: a branching unit; a plurality of indoor units; an outdoor unit; a plurality of supply branch lines and a plurality of return branch lines connecting the branching unit to the respective of the plurality of indoor units; and a supply main line and a return main line connecting the branching unit and the outdoor unit.The branching unit comprises a first branching head, a second branching head, a first confluence head, a second confluence head, a plurality of first feed branching line inlet / outlet valves, a plurality of second feed branching line inlet / outlet valves, a plurality of first return branching line inlet / outlet valves, a plurality of second return branching line inlet / outlet valves, a first bypass valve, a second bypass valve, a first pump, a second pump, a first heat exchanger, a second heat exchanger, a first compressor, a first expansion valve, and a first four-way valve, all arranged within the branching unit. The plurality of indoor units comprises a plurality of indoor heat exchangers, each arranged within the plurality of indoor units.One end of each of the plurality of feed branch lines is connected to the first branch head by a corresponding first feed branch line inlet / outlet valve, and to the second branch head by a corresponding second feed branch line inlet / outlet valve. Another end of each of the plurality of feed branch lines is connected to one end of a corresponding interior heat exchanger. One end of each of the plurality of return branch lines is connected to the first confluence head by a corresponding first return branch line inlet / outlet valve, and to the second confluence head by a corresponding second return branch line inlet / outlet valve.One end of each of the multiple return branch lines is connected to another end of a corresponding multiple interior heat exchanger. The first branch head and the first confluence head are connected by the first bypass valve. The second branch head and the second confluence head are connected by the second bypass valve. The first confluence head, the first pump, the first heat exchanger, and the first branch head are connected to form a first piping path that allows a heat transfer medium to flow in the sequence of the first confluence head, the first pump, the first heat exchanger, and the first branch head.The second confluence head, the second pump, the second heat exchanger, and the second branch head are connected to form a second piping path, allowing the heat transfer fluid to flow through the sequence of the second confluence head, the second pump, the second heat exchanger, and the second branch head. The first compressor, the first four-way valve, the first heat exchanger, the first expansion valve, and the second heat exchanger are connected to form a first refrigerant piping path, allowing refrigerant to flow.The first four-way valve is configured to switch between directing the refrigerant to flow through the first compressor, first four-way valve, first heat exchanger, first expansion valve, second heat exchanger, and first four-way valve, or to directing the refrigerant to flow through the first compressor, first four-way valve, second heat exchanger, first expansion valve, first heat exchanger, and first four-way valve. One end of the supply line is connected to one end of the outdoor unit. Another end of the supply line is connected to the second piping path. One end of the return line is connected to another end of the outdoor unit. Another end of the return line is connected to the second piping path.In the first heat exchanger, heat is exchanged between the refrigerant flowing in the first refrigerant line and the heat transfer medium flowing in the same line. In the second heat exchanger, heat is exchanged between the refrigerant flowing in the first refrigerant line and the heat transfer medium flowing in the second line. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0011] In the air conditioning system according to the present disclosure, the amount of refrigerant filled can be reduced and a test run can be carried out with a branching unit and an indoor unit. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a refrigerant circuit representation of an air conditioning system according to a first embodiment. Fig. Figure 2 is a refrigerant circuit diagram of the air conditioning system according to the first embodiment during a cooling-only operation. Fig. 3 is a refrigerant circuit diagram of the air conditioning system according to the first embodiment during a main cooling operation. Fig. 4 is a refrigerant circuit diagram of the air conditioning system according to the first embodiment during a heating-only operation. Fig. 5 is a refrigerant circuit diagram of the air conditioning system according to the first embodiment during a main heating operation. Fig. Figure 6 is a refrigerant circuit diagram of the air conditioning system according to the first embodiment during a low-outside-air cooling operation. Fig. 7 is a refrigerant circuit diagram of an air conditioning system according to a second embodiment. Fig. Figure 8 is a refrigerant circuit diagram of an air conditioning system according to a third embodiment. Fig. Figure 9 shows a refrigerant circuit diagram of the air conditioning system according to the third embodiment during a cooling-only operation. Fig. 10 is a refrigerant circuit diagram of the air conditioning system according to the third embodiment during a main cooling operation. Fig. 11 is a refrigerant circuit diagram of the air conditioning system according to the third embodiment during a heating-only operation. Fig. 12 is a refrigerant circuit diagram of the air conditioning system according to the third embodiment during a main heating operation. Fig. 13 is a refrigerant circuit diagram of an air conditioning system according to a fourth embodiment during a defrosting operation. Fig. 14 is a refrigerant circuit diagram of an air conditioning system according to a fifth embodiment. Fig. Figure 15 is a cross-sectional view of a supply branch line and a return branch line and a supply main line and a return main line of an air conditioning system according to a sixth embodiment. DESCRIPTION OF THE EXECUTION FORMS

[0012] The embodiments are described below with reference to the drawings. In the drawings, identical or corresponding parts are designated with the same reference numerals, and their descriptions are not repeated in principle. First embodiment.

[0013] A configuration of an air conditioning system 100 according to a first embodiment is described with reference to Fig. 1 described. As in Fig. As shown in Figure 1, the air conditioning system 100 according to the first embodiment comprises a branching unit 10, a plurality of indoor units 50a, 50b, 50c, an outdoor unit 60, a plurality of supply branch lines 51a, 51c, 51c, and a plurality of return branch lines 52a, 52c, 52c, a supply main line 61, and a return main line 62. The plurality of supply branch lines 51 and the plurality of return branch lines 52 connect the branching unit 10 to the respective plurality of indoor units 50a, 50b, and 50c. In the present embodiment, the air conditioning system 100 comprises three indoor units 50a, 50b, and 50c. It can contain any number of indoor units, as long as a plurality of indoor units is included. The main supply line 61 and the main return line 62 connect the branching unit 10 and the outdoor unit 60.

[0014] The branching unit 10 comprises a first branch head 13, a second branch head 23, a first confluence head 16, a second confluence head 26, a plurality of first feed branch line inlet / outlet valves 14a, 14b and 14c, a plurality of second feed branch line inlet / outlet valves 24a, 24b and 24c, a plurality of first return branch line inlet / outlet valves 15a, 15b and 15c, a plurality of second return branch line inlet / outlet valves 25a, 25b and 25c, a first bypass valve 17, a second bypass valve 27, a first pump 11, a second pump 21, a first heat exchanger 12, a second heat exchanger 22, a first compressor 31, a first expansion valve 32 and a first four-way valve 18, which are arranged in the branching unit 10.

[0015] The multiple indoor units 50a, 50b, and 50c each have multiple internal heat exchangers 53a, 53b, and 53c, each arranged within multiple indoor units 50a, 50b, and 50c. The multiple indoor units 50a, 50b, and 50c each have internal fans 54a, 54b, and 54c, each arranged within multiple indoor units 50a, 50b, and 50c.

[0016] One end of each of the plurality of feed branch lines 51a, 51b and 51c is connected to the first branch headpiece 13 by a corresponding first feed branch line on / off valve 14a, 14b and 14c and to the second branch headpiece 23 by a corresponding second feed branch line on / off valve 24a, 24b and 24c.

[0017] Each of the plurality of first feed branch line on / off valves 14a, 14b and 14c opens and closes a line path that connects a corresponding plurality of feed branch lines 51a, 51b and 51c to the first branch headpiece 13. Each of the plurality of second feed branch line on / off valves 24a, 24b and 24c opens and closes a line path that connects a corresponding plurality of feed branch lines 51a, 51b and 51c to the second branch headpiece 23. The line path that connects a corresponding number of supply branch lines 51a, 51b and 51c to the second branch headpiece 23 branches off from the line path that connects a corresponding number of supply branch lines 51a, 51b and 51c to the first branch headpiece 13.

[0018] Another end of each of the plurality of supply branch lines 51a, 51b and 51c is connected to one end of a corresponding plurality of interior heat exchangers 53a, 53b and 53c.

[0019] One end of each of the plurality of return branch lines 52a, 52b and 52c is connected to the first confluence headpiece 16 by a corresponding plurality of first return branch line in-off valves 15a, 15b and 15c and to the second confluence headpiece 26 by a corresponding plurality of second return branch line in-off valves 25a, 25b and 25c.

[0020] Each of the plurality of first return branch line on / off valves 15a, 15b and 15c opens and closes a line path that connects a corresponding plurality of return branch lines 52a, 52b and 52c to the first confluence headpiece 16. Each of the plurality of second return branch line on / off valves 25a, 25b and 25c opens and closes a line path that connects a corresponding plurality of return branch lines 52a, 52b and 52c to the second confluence headpiece 26. The conduit path connecting a corresponding plurality of return branch lines 52a, 52b and 52c to the second confluence headpiece 26 branches off from the conduit path connecting a corresponding plurality of return branch lines 52a, 52b and 52c to the first confluence headpiece 16.

[0021] Another end of each of the plurality of return branch lines 52a, 52b and 52c is connected to another end of a corresponding plurality of interior heat exchangers 53a, 53b and 53c.

[0022] The first branch headpiece 13 and the first confluence headpiece 16 are connected by the first bypass valve 17. The first bypass valve 17 opens and closes a bypass path that connects the first branch headpiece 13 with the first confluence headpiece 16.

[0023] The second branch headpiece 23 and the second confluence headpiece 26 are connected to each other by the second bypass valve 27. The second bypass valve 27 opens and closes a bypass path that connects the second branch headpiece 23 with the second confluence headpiece 26.

[0024] The first confluence head 16, the first pump 11, the first heat exchanger 12, and the first branch head 13 are connected to form a first conduit path P1, which allows a heat transfer medium to flow through the sequence of the first confluence head 16, the first pump 11, the first heat exchanger 12, and the first branch head 13. The first confluence head 16, the first pump 11, the first heat exchanger 12, and the first branch head 13 are connected by a conduit, thus forming the first conduit path P1.

[0025] The second confluence head 26, the second pump 21, the second heat exchanger 22, and the second branch head 23 are connected to form a second conduit path P2, which allows a heat transfer medium to flow through the sequence of the second confluence head 26, the second pump 21, the second heat exchanger 22, and the second branch head 23. The second confluence head 26, the second pump 21, the second heat exchanger 22, and the second branch head 23 are connected by a conduit, thus forming the second conduit path P2.

[0026] The first compressor 31, the first four-way valve 18, the first heat exchanger 12, the first expansion valve 32, and the second heat exchanger 22 are connected to form a first refrigerant line path R1, which allows refrigerant to flow. The first compressor 31, the first four-way valve 18, the first heat exchanger 12, the first expansion valve 32, and the second heat exchanger 22 are connected by a line, thus forming a first refrigerant line path R1. The first refrigerant line path R1 has a refrigeration cycle.

[0027] The first four-way valve 18 is configured to be switched to cause the refrigerant to flow in the sequence of the first compressor 31, the first four-way valve 18, the first heat exchanger 12, the first expansion valve 32, the second heat exchanger 22 and the first four-way valve 18, or to cause the refrigerant to flow in the sequence of the first compressor 31, the first four-way valve 18, the second heat exchanger 22, the first expansion valve 32, the first heat exchanger 12 and the first four-way valve 18.

[0028] One end of the main supply line 61 is connected to one end of the outdoor unit 60. Another end of the main supply line 61 is connected to a second line path P2. The other end of the main supply line 61 can be detachably connected to a second line path P2. A connecting section between the second line path P2 and the other end of the main supply line 61 is designed to allow the second line path P2 to be closed.

[0029] One end of a return main line 62 is connected to another end of an outdoor unit 60. Another end of a return main line 62 is connected to the second line path P2. The other end of a return main line 62 can be detachably connected to the second line path P2. A connecting section between the second line path P2 and the other end of the return main line 62 is designed to allow the second line path P2 to be closed.

[0030] The connecting section between the second line path P2 and the other end of the main supply line 61 closes the second line path P2 and the connecting section between the second line path P2 and the other end of the main return line 62 closes the second line path P2, thus forming a closed circuit for the second line path P2.

[0031] In the first heat exchanger 12, heat is exchanged between the refrigerant flowing in the first refrigerant line path R1 and the heat medium flowing in a first line path P1.

[0032] In the second heat exchanger 22, heat is exchanged between the refrigerant flowing in the first refrigerant line path R1 and the heat medium flowing in the second line path P2.

[0033] The branching unit 10 includes a flow rate adjustment valve 33 located within the branching unit 10 and in the second line path P2. The flow rate adjustment valve 33 opens and closes the second line path P2. The flow rate adjustment valve 33 is connected between a branch point from the main supply line 61 and a junction point with the main return line 62 in the second line path P2.

[0034] The outdoor unit 60 includes a cooling tower 63 located within it. The cooling tower 63 and the branching unit 10 are connected to each other by the supply line 61 and the return line 62. The outdoor unit 60 includes a fan 64 located within it.

[0035] One end of the main supply line 61 is connected to one end of the cooling tower 63. The other end of the main supply line 61 is connected between the second pump 21 and the second heat exchanger 22 in the second piping path P2. The other end of the main supply line 61 is connected to a line in the second piping path P2 that connects the second pump 21 and the second heat exchanger 22.

[0036] One end of the return main line 62 is connected to another end of the cooling tower 63. The other end of the return main line 62 is connected between the second pump 21 and the second heat exchanger 22 in the second line path P2. The other end of the return main line 62 is connected to the line that connects the second pump 21 and the second heat exchanger 22 in the second line path P2.

[0037] The capacity of the second pump 21 is greater than the capacity of the first pump 11. <Betrieb der Klimaanlage>

[0038] Depending on the operating mode of the multiple indoor units 50a, 50b, and 50c and the outside air temperature, the air conditioner 100 operates in either cooling-only mode, primarily cooling mode, heating-only mode, primarily heating mode, or low-outside-air-temperature cooling mode. When multiple indoor units 50a, 50b, and 50c are operating and all are in cooling mode, the air conditioner 100 operates in cooling-only mode. When multiple indoor units 50a, 50b, and 50c are operating and all are in heating mode, the air conditioner 100 operates in heating-only mode. Cooling and heating modes can be active simultaneously in multiple indoor units 50a, 50b, and 50c.If the sum of the air conditioning loads of the indoor units in cooling mode is greater than the sum of the air conditioning loads of the indoor units in heating mode, the air conditioner 100 operates in primary cooling mode. If the sum of the air conditioning loads of the indoor units in heating mode is greater than the sum of the air conditioning loads of the indoor units in cooling mode, the air conditioner 100 operates in primary heating mode. If the multiple indoor units 50a, 50b, and 50c are all operating in cooling mode and the outside temperature is sufficiently lower than the inside temperature (e.g., if the outside air temperature is equal to or less than 5°C), the air conditioner 100 operates in low-outside-air cooling mode. <Nur-Kühlung-Betrieb>

[0039] The cooling-only operation of the air conditioner 100 is demonstrated using the following: Fig. 2 described. If, as in Fig. Figure 2 shows all of the multiple indoor units 50a, 50b, and 50c operating in cooling mode, while the air conditioner 100 operates in cooling-only mode. In cooling-only mode, the multiple first supply branch line on / off valves 14a, 14b, and 14c, the multiple first return branch line on / off valves 15a, 15b, and 15c, and the second bypass valve 27 are opened, and the multiple second supply branch line on / off valves 24a, 24b, and 24c, the multiple second return branch line on / off valves 25a, 25b, and 25c, the first bypass valve 17, and the flow rate adjustment valve 33 are closed.This creates a cold water circuit extending from the first pump 11 through the first heat exchanger 12, the first branch head 13, the plurality of first supply branch line inlet / outlet valves 14a, 14b and 14c, the plurality of supply branch lines 51a, 51b and 51c, the plurality of internal heat exchangers 53a, 53b and 53c, the plurality of return branch lines 52a, 52b and 52c, the plurality of first return branch line inlet / outlet valves 15a, 15b and 15c and the first junction head 16 to reach the first pump 11 again. Furthermore, a hot water circuit is formed, extending from the second pump 21 through the supply main line 61, the cooling tower 63, the return main line 62, the second heat exchanger 22, the second branch headpiece 23, the second bypass valve 27 and the second junction headpiece 26, to reach the second pump 21 again.

[0040] In the refrigeration circuit, a refrigerant circuit is formed in which the refrigerant flows from the first compressor 31 through the first four-way valve 18, the second heat exchanger 22, the first expansion valve 32, the first heat exchanger 12, and the first four-way valve 18 again to return to the first compressor 31. In this case, the second heat exchanger 22 acts as a condenser and the first heat exchanger 12 acts as an evaporator.

[0041] First, the operation of the refrigeration circuit is described. The gaseous single-phase refrigerant discharged from the first compressor 31 flows through the first four-way valve 18 into the second heat exchanger 22 and condenses to liquid single-phase refrigerant through heat exchange with the heat transfer medium of the hot water circuit flowing in the second heat exchanger 22. The liquid single-phase refrigerant flowing from the second heat exchanger 22 flows into the first expansion valve 32 and is decompressed and expanded to a gaseous two-phase refrigerant. The gaseous-liquid two-phase refrigerant flows into the first heat exchanger 12 and evaporates to gaseous single-phase refrigerant through heat exchange with the heat transfer medium of the chilled water circuit flowing in the first heat exchanger 12. The gaseous single-phase refrigerant flowing out of the first heat exchanger 12 is drawn back into the first compressor 31 and circulates in the refrigerant circuit.

[0042] The operation of the chilled water circuit is then described. The heat transfer medium circulating in the chilled water circuit is water or antifreeze. The heat transfer medium flowing out of the first pump 11 is cooled by heat exchange with the refrigerant in the first heat exchanger 12 and flows through the first branch head 13, the multiple supply branch line inlet / outlet valves 14a, 14b and 14c, and the multiple supply branch lines 51a, 51b and 51c into the multiple internal heat exchangers 53a, 53b and 53c in the multiple indoor units 50a, 50b and 50c. While the multitude of indoor units 50a, 50b and 50c is in operation, the multitude of indoor fans 54a, 54b and 54c is in operation and the heat medium cools the indoor air blown in by the multitude of indoor fans 54a, 54b and 54c in the multitude of indoor heat exchangers 53a, 53b and 53c.The heat medium, whose temperature has been increased by heat exchange with the indoor air, flows through the multitude of return branch lines 52a, 52b and 52c, the multitude of first return branch line inlet / outlet valves 15a, 15b and 15c and the first junction headpiece 16 into the first pump 11 and circulates in the cold water circuit.

[0043] The operation of the hot water circuit is then described. The heat transfer medium circulating in the hot water circuit is water or antifreeze. The heat transfer medium exiting the second pump 21 flows through the main supply line 61 to the cooling tower 63 and releases heat to the outside air. The heat transfer medium, whose temperature has been reduced by releasing heat to the outside air, flows through the main return line 62 into the second heat exchanger 22 in the branch unit 10 and is heated by heat exchange with the refrigerant. The heat transfer medium, whose temperature has been increased by heat exchange with the refrigerant, flows through the second branch head 23, the second bypass valve 27, and the second convergence head 26 into the second pump 21 and circulates in the hot water circuit.

[0044] The refrigeration circuit in the branch unit 10 generates cold heat, which is required by the multiple indoor units 50a, 50b, and 50c during cooling operation. The chilled water circuit supplies the low-temperature heat transfer fluid to the multiple indoor units 50a, 50b, and 50c via the first heat exchanger 12. The hot waste heat generated during refrigeration operation is transferred to the high-temperature heat transfer fluid via the second heat exchanger 22 and discharged from the cooling tower 63 of the outdoor unit 60 via the hot water circuit. <Hauptsächlich-Kühlung-Betrieb>

[0045] The primary cooling operation of the air conditioner 100 is based on... Fig. 3 described. As in Fig. As shown in Figure 3, the air conditioner 100 performs the main cooling operation when the multiple indoor units 50a and 50b are operating in cooling mode and the indoor unit 50c is operating in heating mode. In main cooling operation, the multitude of first feed branch line inlet / outlet valves 14a and 14b, the multitude of first return branch line inlet / outlet valves 15a and 15b, the second feed branch line inlet / outlet valve 24c, the second return branch line inlet / outlet valve 25c and the second bypass valve 27 are opened, and the first feed branch line inlet / outlet valve 14c, the first return branch line inlet / outlet valve 15c, the first bypass valve 17, the multitude of second feed branch line inlet / outlet valves 24a and 24b, the multitude of second return branch line inlet / outlet valves 25a and 25b and the flow rate adjustment valve 33 are opened. closed.Thus, a cold water circuit is formed, extending from the first pump 11 through the first heat exchanger 12, the first branch head 13, the plurality of first supply branch line inlet / outlet valves 14a and 14b, the plurality of supply branch lines 51a and 51b, the plurality of internal heat exchangers 53a and 53b, the plurality of return branch lines 52a and 52a, the plurality of first return branch line inlet / outlet valves 15a and 15b and the first junction head 16 to reach the first pump 11 again.Furthermore, a hot water circuit is formed, extending from the second pump 21 through the main supply line 61, the cooling tower 63, the main return line 62, the second heat exchanger 22, the second branch head 23, the second supply branch line inlet / outlet valve 24c, the supply branch line 51c, the internal heat exchanger 53c, the return branch line 52c, the second return branch line inlet / outlet valve 25c and the second confluence head 26 or through the second branch head 23, the second bypass valve 27 and the second confluence head 26 to reach the second pump 21 again.

[0046] The operation of the refrigeration circuit is the same as during cooling-only operation.

[0047] Operating the cold water circuit is similar to operating it during cooling-only operation.

[0048] The operation of the hot water circuit is then described. The heat transfer medium flowing from the second pump 21 flows through the main supply line 61 to the cooling tower 63 and releases heat to the outside air. The heat transfer medium, whose temperature has been reduced by releasing heat to the outside air, flows through the main return line 62 into the second heat exchanger 22 in the branch unit 10 and is heated by heat exchange with the refrigerant. The heat transfer medium, whose temperature has been increased by heat exchange with the refrigerant, flows through the second branch head 23, the second supply branch line inlet / outlet valve 24c, and the supply branch line 51a into the indoor heat exchanger 53 in the indoor unit 50c. During operation of the indoor unit 50c, the indoor fan 54c operates, and the heat transfer medium heats the indoor air blown into the indoor heat exchanger 53c by the indoor fan 54c.The heat transfer medium, whose temperature has been reduced by heat exchange with the indoor air, flows through the return branch line 52c and the second return branch line inlet / outlet valve 25c to the second junction head 26. The remaining heat transfer medium, not conveyed to the internal heat exchanger 53c, flows through the second bypass valve 27 to the second junction head 26, mixes with the heat transfer medium returned from the internal heat exchanger 53c, flows into the first pump 11 and circulates in the hot water circuit.

[0049] The refrigeration circuit in the branch unit 10 generates cold heat, which is required by the multiple indoor units 50a and 50b during cooling operation. The chilled water circuit supplies the multiple indoor units 50a and 50b with the low-temperature heat transfer medium via the first heat exchanger 12. The hot heat generated during refrigeration operation is supplied to the indoor unit 50c via the hot water circuit through the second heat exchanger 22 during heating operation, and the remaining hot waste heat is discharged from the cooling tower 63 to the outdoor unit 60 via the hot water circuit.

[0050] If the amount of hot waste heat in the cooling tower 63 is small, the second bypass valve 27 can be closed. If the amount of hot waste heat in the cooling tower 63 is large, the second bypass valve 27 is opened, thereby reducing the flow rate of the heat medium flowing through the internal heat exchanger 53c to prevent too much hot waste heat from entering the interior space from the internal heat exchanger 53c.

[0051] If the amount of hot waste heat in the outdoor unit 60 is small, the flow rate adjustment valve 33 can be opened. Generally, the branch unit 10 and the outdoor unit 60 are positioned at a distance. Therefore, by opening the flow rate adjustment valve 33, the flow rate of the heat medium flowing through the supply line 61 and the return line 62 can be reduced, leading to a reduction in the energy consumption of the second pump 21 caused by line friction losses in the supply line 61 and the return line 62. <Nur-Erwärmung-Betrieb>

[0052] The heating-only mode of the air conditioner 100 is demonstrated using the following: Fig. 4 described. If, as in Fig. As shown in Figure 4, with all of the multiple indoor units 50a, 50b, and 50c operating in heating mode, the air conditioner 100 operates in heating-only mode. Multiple first supply branch line on / off valves 14a, 14b, and 14c, multiple first return branch line on / off valves 15a, 15b, and 15c, and the second bypass valve 27 are opened, and multiple second supply branch line on / off valves 24a, 24b, and 24c, multiple second return branch line on / off valves 25a, 25b, and 25c, the first bypass valve 17, and the flow rate adjustment valve 33 are closed.This creates a hot water circuit extending from the first pump 11 through the first heat exchanger 12, the first branch head 13, the plurality of first supply branch line inlet / outlet valves 14a, 14b and 14c, the plurality of supply branch lines 51a, 51b and 51c, the plurality of internal heat exchangers 53a, 53b and 53c, the plurality of return branch lines 52a, 52b and 52c, the plurality of first return branch line inlet / outlet valves 15a, 15b and 15c and the first junction head 16 to reach the first pump 11 again. Furthermore, a cold water circuit is formed, extending from the second pump 21 through the supply main line 61, the cooling tower 63, the return main line 62, the second heat exchanger 22, the second branch headpiece 23, the second bypass valve 27 and the second confluence headpiece 26, to reach the second pump 21 again.

[0053] In the refrigeration circuit, a refrigerant circuit is formed in which the refrigerant flows from the first compressor 31 through the first four-way valve 18, the first heat exchanger 12, the first expansion valve 32, the second heat exchanger 22, and the first four-way valve 18 again to reach the first compressor 31. In this case, the first heat exchanger 12 acts as a condenser and the second heat exchanger 22 acts as an evaporator.

[0054] First, the operation of the refrigeration circuit is described. The gaseous single-phase refrigerant discharged from the first compressor 31 flows through the first four-way valve 18 into the first heat exchanger 12 and condenses to liquid single-phase refrigerant through heat exchange with the heat transfer medium of the hot water circuit flowing in the first heat exchanger 12. The liquid single-phase refrigerant flowing from the first heat exchanger 12 flows into the first expansion valve 32 and is decompressed and expanded to a gaseous two-phase refrigerant. The gaseous-liquid two-phase refrigerant flows into the second heat exchanger 22 and evaporates to gaseous single-phase refrigerant through heat exchange with the heat transfer medium of the chilled water circuit flowing in the second heat exchanger 22. The gaseous single-phase refrigerant flowing out of the second heat exchanger 22 is drawn back into the first compressor 31 and circulates in the refrigerant circuit.

[0055] The operation of the hot water circuit is then described. The heat medium circulating in the hot water circuit is water or antifreeze. The heat medium flowing from the first pump 11 is heated by heat exchange with the refrigerant in the first heat exchanger 12 and flows through the first branch head 13, the multiple supply branch line inlet / outlet valves 14a, 14b and 14c, and the multiple supply branch lines 51a, 51b and 51c into the multiple indoor heat exchangers 53a, 53b and 53c in the multiple indoor units 50a, 50b and 50c. While the multitude of indoor units 50a, 50b and 50c is in operation, the multitude of indoor blowers 54a, 54b and 54c are in operation and the heat medium heats the indoor air blown in by the multitude of indoor blowers 54a, 54b and 54c in the multitude of indoor heat exchangers 53a, 53b and 53c.The heat medium, whose temperature has been reduced by heat exchange with the indoor air, flows through the multitude of return branch lines 52a, 52b and 52c, the multitude of first return branch line inlet / outlet valves 15a, 15b and 15c and the first junction headpiece 16 into the first pump 11 and circulates in the hot water circuit.

[0056] The operation of the chilled water circuit is then described. The heat transfer medium circulating in the chilled water circuit is water or antifreeze. The heat transfer medium exiting the second pump 21 flows through the main supply line 61 to the cooling tower 63 and absorbs heat from the outside air. The heat transfer medium, whose temperature has been reduced by heat absorption from the outside air, flows through the main return line 62 into the second heat exchanger 22 in the branch unit 10 and is cooled by heat exchange with the refrigerant. The heat transfer medium, whose temperature has been reduced by heat exchange with the refrigerant, flows through the second branch head 23, the second bypass valve 27, and the second convergence head 26 into the second pump 21 and circulates in the chilled water circuit.

[0057] The refrigeration circuit in the branch unit 10 generates hot heat, which is required by the multiple indoor units 50a, 50b, and 50c during heating operation. The hot water circuit supplies the indoor units 50a, 50b, and 50c with the high-temperature heating medium via the first heat exchanger 12. The cold waste heat generated during refrigeration operation is transferred to the low-temperature heating medium via the second heat exchanger 22 and discharged from the cooling tower 63 of the outdoor unit 60 via the chilled water circuit. <Hauptsächlich-Erwärmung-Betrieb>

[0058] The primary heating operation of the air conditioner 100 is based on Fig. 5 described. As in Fig. As shown in Figure 5, the air conditioner 100 performs the main heating operation when the multiple indoor units 50a and 50b are operating in heating mode and the indoor unit 50c is operating in cooling mode. In main heating operation, the plurality of first feed branch line inlet / outlet valves 14a and 14b, the plurality of first return branch line inlet / outlet valves 15a and 15b, the second feed branch line inlet / outlet valve 24c, the second return branch line inlet / outlet valve 25c and the second bypass valve 27 are opened, and the first feed branch line inlet / outlet valve 14c, the first return branch line inlet / outlet valve 15c, the first bypass valve 17, the plurality of second feed branch line inlet / outlet valves 24a and 24b, the plurality of second return branch line inlet / outlet valves 25a and 25b and the flow rate adjustment valve 33 are opened. closed.Thus, a hot water circuit is formed, extending from the first pump 11 through the first heat exchanger 12, the first branching headpiece 13, the plurality of first supply branch line inlet / outlet valves 14a and 14b, the plurality of supply branch lines 51a and 51b, the plurality of internal heat exchangers 53a and 53b, the plurality of return branch lines 52a and 52a, the plurality of first return branch line inlet / outlet valves 15a and 15b and the first junction headpiece 16 to reach the first pump 11 again.Furthermore, a cold water circuit is formed, extending from the second pump 21 through the supply main line 61, the cooling tower 63, the return main line 62, the second heat exchanger 22, the second branch head 23, the second supply branch line inlet / outlet valve 24c, the supply branch line 51c, the internal heat exchanger 53c, the return branch line 52c, the second return branch line inlet / outlet valve 25c and the second confluence head 26 or through the second branch head 23, the second bypass valve 27 and the second confluence head 26 to reach the second pump 21 again.

[0059] The operation of the refrigeration circuit is the same as during heating-only operation.

[0060] The operation of the hot water circuit is also similar to that during heating-only operation.

[0061] The operation of the chilled water circuit is then described. The heat transfer fluid exiting the second pump 21 flows through the main supply line 61 to the cooling tower 63 and absorbs heat from the outside air. The heat transfer fluid, whose temperature has been reduced by heat absorption from the outside air, flows through the main return line 62 into the second heat exchanger 22 in the branch unit 10 and is cooled by heat exchange with the refrigerant. The heat transfer fluid, whose temperature has been reduced by heat exchange with the refrigerant, flows through the second branch head 23, the second supply branch line inlet / outlet valve 24c, and the supply branch line 51a into the indoor heat exchanger 53 in the indoor unit 50c. While the indoor unit 50c is operating, the indoor fan 54c is operating and the heat medium cools the indoor air blown into the indoor heat exchanger 53c by the indoor fan 54c.The heat transfer medium, whose temperature has been increased by heat exchange with the indoor air, flows through the return branch line 52c and the second return branch line inlet / outlet valve 25c to the second junction head 26. The remaining heat transfer medium, not conveyed to the internal heat exchanger 53c, flows through the second bypass valve 27 to the second junction head 26, mixes with the heat transfer medium returned from the internal heat exchanger 53c, flows into the second pump 21 and circulates in the cold water circuit.

[0062] The refrigeration circuit in the branch unit 10 generates hot heat, which is required by the multiple indoor units 50a and 50b during heating operation. The hot water circuit supplies the multiple indoor units 50a and 50b with the high-temperature heat transfer medium via the first heat exchanger 12. The cold heat generated during refrigeration operation is supplied to the indoor unit 50c via the chilled water circuit through the second heat exchanger 22 during cooling operation, and the remaining cold waste heat is discharged from the cooling tower 63 to the outdoor unit 60 via the chilled water circuit.

[0063] If the amount of cold waste heat in the outdoor unit 60 is small, the second bypass valve 27 can be closed. If the amount of cold waste heat in the outdoor unit 60 is large, the second bypass valve 27 is opened, thereby reducing the flow rate of the heat medium flowing through the indoor heat exchanger 53c to prevent excessive cooling from the indoor heat exchanger 53c to the indoor space.

[0064] If the amount of cold waste heat in the outdoor unit 60 is small, the flow rate adjustment valve 33 can be opened. Generally, the branch unit 10 and the outdoor unit 60 are positioned at a distance. Therefore, by opening the flow rate adjustment valve 33, the flow rate of the heat medium flowing through the supply line 61 and the return line 62 can be reduced, leading to a reduction in the energy consumption of the second pump 21 caused by line friction losses in the supply line 61 and the return line 62. <Niedrige-Außenluft-Kühlungsbetrieb>

[0065] The low-outside-air cooling mode of the air conditioner 100 is based on Fig. 6 described. If, as in Fig. Figure 6 shows that when all of the multiple indoor units 50a, 50b and 50c are operating in cooling mode and the outside temperature is sufficiently lower than the inside temperature (e.g., when the outside air temperature is equal to or lower than 5°C), the air conditioner 100 performs the low-outside-air cooling operation. In low-outside-air cooling operation, the multitude of second supply branch line inlet / outlet valves 24a, 24b and 24c and the multitude of second return branch line inlet / outlet valves 25a, 25b and 25c are opened, and the multitude of first supply branch line inlet / outlet valves 14a, 14b and 14c, the multitude of first return branch line inlet / outlet valves 15a, 15b and 15c, the first bypass valve 17, the second bypass valve 27 and the flow rate adjustment valve 33 are closed.This creates a cold water circuit extending from the second pump 21 through the supply main line 61, the cooling tower 63, the return main line 62, the second heat exchanger 22, the second branch head 23, the multitude of second supply branch line inlet / outlet valves 24a, 24b and 24c, the multitude of supply branch lines 51a, 51b and 51c, the multitude of internal heat exchangers 53a, 53b and 53c, the multitude of return branch lines 52a, 52b and 52c, the multitude of second return branch line inlet / outlet valves 25a, 25b and 25c and the second junction head 26 to reach the second pump 21 again.

[0066] In this case, the first compressor 31 in the refrigeration circuit is not in operation and the first heat exchanger 12 and the second heat exchanger 22 do not function as sources of hot or cold heat.

[0067] The operation of the chilled water circuit is then described. The heat medium flowing out of the second pump 21 flows through the main supply line 61 to the cooling tower 63 and releases heat to the outside air. The heat medium, whose temperature has been reduced by heat loss to the outside air, flows through the return main line 62 and through the second heat exchanger 22, the second branch head 23, the multiple inlet / outlet valves 24a, 24b and 24c of the second supply branch line, and the multiple supply branch lines 51a, 51b and 51c in the branch unit 10 into the internal heat exchangers 53a, 53b and 53c in the multiple internal units 50a, 50b and 50c. While the multitude of indoor units 50a, 50b and 50c is in operation, the multitude of indoor fans 54a, 54b and 54c is in operation and the heat medium cools the indoor air blown in by the multitude of indoor fans 54a, 54b and 54c in the multitude of indoor heat exchangers 53a, 53b and 53c.The heat medium, whose temperature has been increased by heat exchange with the indoor air, flows through the multitude of second return branch line inlet / outlet valves 25a, 25b and 25c and the second junction headpiece 26 into the second pump 21 and circulates in the cold water circuit.

[0068] The cold heat required by the multiple indoor units 50a, 50b, and 50c during cooling operation is provided entirely by heat absorption from the outside air, which has a lower temperature than the indoor air, and by transferring cold heat via the chilled water circuit. In low-outdoor-air cooling mode, the operation of the first compressor 31 in the refrigeration circuit is stopped; the low-temperature outside air is used directly as the source of cold heat, and only the second pump 21 is operated. Therefore, cooling of the multiple indoor units 50a, 50b, and 50c can be achieved with low energy consumption. <Funktionen und Auswirkungen>

[0069] In the air conditioning system 100 according to the first embodiment, the branching unit 10 is connected to the respective plurality of indoor units 50a, 50b, and 50c by the plurality of supply branch lines 51 and the plurality of return branch lines 52, and the first refrigerant line path R1 is located in the branching unit 10. Therefore, the refrigerant flows only in the branching unit 10. Compared to the case in which the refrigerant flows through the plurality of indoor units 50a, 50b, and 50c and the outdoor unit 60, the amount of refrigerant required can thus be reduced. Reducing the amount of refrigerant required can lead to a reduction in refrigerant costs. Reducing the amount of refrigerant required can also lead to a reduction in the refrigerant's impact on global warming.

[0070] Furthermore, the branching unit 10 is connected to the respective multiple indoor units 50a, 50b, and 50c via the plurality of supply branch lines 51 and the plurality of return branch lines 52, and the first line path P1, second line path P2, and the first refrigerant line path R1 are arranged in the branching unit 10. In the first heat exchanger 12, which is arranged in the branching unit 10, heat is exchanged between the refrigerant flowing in the first refrigerant line path R1 and the heat transfer medium flowing in the first line path P1. In the second heat exchanger 22, which is arranged in the branching unit 10, heat is exchanged between the refrigerant flowing in the first refrigerant line path R1 and the heat transfer medium flowing in the second line path P2.Therefore, heat exchange between the refrigerant and the heat transfer medium can be carried out between branch unit 10 and the multiple indoor units 50a, 50b, and 50c. This allows a test run to be performed with branch unit 10 and the multiple indoor units 50a, 50b, and 50c.

[0071] In the air conditioning system 100 according to the first embodiment, the flow rate adjustment valve 33 is connected between the branch point from the supply line 61 and the junction point with the return line 62 in the second line path P2. By opening the flow rate adjustment valve 33, the flow rate of the heat medium flowing through the supply line 61 and the return line 62 can therefore be reduced, which leads to a reduction in the energy consumption of the second pump 21 caused by line friction losses in the supply line 61 and in the return line 62.

[0072] In the air conditioning system 100 according to the first embodiment, the outdoor unit 60 has a cooling tower 63 located within the outdoor unit 60. Therefore, during refrigeration operation, any excess heat from the hot heat source or the cold heat source, when the multiple indoor units 50a, 50b, and 50c are performing cooling and heating, can be discharged into the cooling tower 63. In this way, the cooling and heating capacities of the multiple indoor units 50a, 50b, and 50c can be adjusted without over- or under-supply.

[0073] In the air conditioning system 100 according to the first embodiment, the hot heat and cold heat generated by the refrigeration circuit in the branching unit 10 can be used to switch between cooling-only operation, primarily cooling operation, heating-only operation, and primarily heating operation in accordance with a setting of each of the plurality of indoor units 50a, 50b, and 50c in each of the cooling and heating operating modes. For example, in an air conditioning system of a large building, there is a case where, if the operating state of an indoor unit located in a common room is set to heating, the operating state of an indoor unit located in a room such as a computer room or a kitchen, where a large amount of heat is generated, is set to cooling.The air conditioning unit 100 according to the first embodiment is suitable for such an air conditioning system.

[0074] In the air conditioning system 100 according to the first embodiment, the capacity of the second pump 21 is greater than the capacity of the first pump 11. The larger capacity of the second pump 21 in the second line path P2, which is connected to the outdoor unit 60, facilitates the supply of the heat medium to the outdoor unit 60 by the second pump 21.

[0075] Furthermore, in the air conditioning system 100 according to the first embodiment, the refrigeration circuit is provided only in the branching unit 10, and the heat transfer between the branching unit 10 and the plurality of indoor units 50a, 50b and 50c, as well as between the branching unit 10 and the cooling tower 63, is carried out using the heat transfer medium (water or antifreeze). Therefore, the amount of refrigerant charged can be reduced regardless of the pipe length between the branching unit 10 and the plurality of indoor units 50a, 50b and 50c, as well as the pipe length between the branching unit 10 and the cooling tower 63.

[0076] Furthermore, in the air conditioning system 100 according to the first embodiment, the two lines are used for the connection between the branching unit 10 and the plurality of indoor units 50a, 50b, and 50c, and for the connection between the branching unit 10 and the cooling tower 63. This reduces installation time and effort, particularly when there are large distances between the branching unit 10 and the indoor units or between the branching unit 10 and the cooling tower 63. Additionally, the internal pressure of a refrigerant line is typically high (up to about 4 megapascals), which complicates its installation, whereas the internal pressure of a water line is relatively low (usually less than 1 megapascal at most), making the water line easier to install than the refrigerant line.

[0077] Furthermore, in low-outdoor air cooling mode, when the outdoor air temperature is sufficiently lower than the indoor temperature of the room in which the multiple indoor units 50a, 50b, and 50c are located during cooling operation, the operation of the first compressor 31 in the refrigeration circuit is stopped, the low-temperature outdoor air is used directly as the source of cold heat, and only the second pump 21 is operated. Therefore, the cooling operation of the multiple indoor units 50a, 50b, and 50c can be achieved with low energy consumption.

[0078] As described above, in the air conditioning system 100 according to the first embodiment, a reduction in the amount of refrigerant used, a reduction in installation difficulties and installation costs, and energy-saving operation in low-outdoor-air cooling mode can be achieved simultaneously. Second embodiment.

[0079] The air conditioning unit 100 according to a second embodiment is identical to the air conditioning unit 100 according to the first embodiment with regard to configuration, operation, functions and effects, unless otherwise described.

[0080] A configuration of an air conditioning system 100 according to the second embodiment is described with reference to Fig. 7 described. As in Fig. As shown in Figure 7, the air conditioning system 100 according to the second embodiment has a ground heat exchanger 70 instead of the cooling tower 63.

[0081] The outdoor unit 60 has a ground-source heat exchanger 70 arranged within the outdoor unit 60. The ground-source heat exchanger 70 and the branching unit 10 are connected to each other by the supply line 61 and the return line 62.

[0082] One end of the supply line 61 is connected to one end of the ground-source heat exchanger 70. The other end of the supply line 61 is connected between the second pump 21 and the second heat exchanger 22 in the second piping path P2. One end of the return line 62 is connected to another end of the ground-source heat exchanger 70. The other end of the return line 62 is connected between the second pump 21 and the second heat exchanger 22 in the second piping path P2.

[0083] Next, the functions and effects of an air conditioner 100 according to the second embodiment will be described.

[0084] To prevent the heat medium (water or antifreeze) flowing through the second pipe path P2 from freezing and to suppress its viscosity increase, a minimum temperature for the heat medium must be set.

[0085] In the air conditioning system 100 according to the first embodiment, it is difficult to extract heat from the outside air in the cooling tower 63 in a case where the heating-only operation or the main heating operation is carried out when the outside air temperature is, for example, below zero.

[0086] The air conditioning unit 100 according to the second embodiment has a ground-source heat exchanger 70. Generally, the temperature in the ground is between 15°C and 25°C and is stable year-round compared to the outside air temperature. Therefore, the ground-source heat exchanger 70 facilitates the extraction of heat from the outside air, so that heating-only operation or primary heating operation can be achieved reliably. Third embodiment.

[0087] The air conditioning unit 100 according to a third embodiment is identical to the air conditioning unit 100 according to the first embodiment with regard to configuration, operation, functions and effects, unless otherwise described.

[0088] A configuration of an air conditioning system 100 according to the third embodiment is described with reference to Fig. 8 described. As in Fig. As shown in Figure 8, the air conditioning system 100 according to the third embodiment has an outdoor unit 40 instead of the cooling tower 63.

[0089] The outdoor unit 60 includes an outdoor unit 40. The outdoor unit 40 includes a second compressor 41, a second four-way valve 48, a second expansion valve 42, a third heat exchanger 43, and a fourth heat exchanger 44, all arranged within the outdoor unit 40. Furthermore, the outdoor unit 40 includes an outdoor fan 45.

[0090] The second compressor 41, the second four-way valve 48, the third heat exchanger 43, the second expansion valve 42 and the fourth heat exchanger 44 are connected to form a second refrigerant piping path R2, which allows refrigerant to flow.

[0091] The external machine 40 and the branching unit 10 are connected to each other by the main supply line 61 and the main return line 62.

[0092] The second four-way valve 48 is configured to be switched to cause the refrigerant to flow in the sequence of the second compressor 41, the second four-way valve 48, the third heat exchanger 43, the second expansion valve 42, the fourth heat exchanger 44 and the second four-way valve 48, or to cause the refrigerant to flow in the sequence of the second compressor 41, the second four-way valve 48, the fourth heat exchanger 44, the second expansion valve 42, the third heat exchanger 43 and the second four-way valve 48.

[0093] One end of the supply line 61 is connected to one end of the third heat exchanger 43. The other end of the supply line 61 is connected between the second heat exchanger 22 and the second branch fitting 23 in the second line path P2. One end of the return line 62 is connected to another end of the third heat exchanger 43. The other end of the return line 62 is connected between the second heat exchanger 22 and the second branch fitting 23 in the second line path P2.

[0094] The suction volume of the second compressor 41 in the external machine 40 is greater than the suction volume of the first compressor 31 in the branching unit 10. <Betrieb der Klimaanlage>

[0095] Depending on the operating mode of the multiple indoor units 50a, 50b, and 50c, the air conditioner 100 operates in cooling-only mode, primarily cooling mode, heating-only mode, or primarily heating mode. Since, according to the third embodiment of the air conditioner 100, the fourth heat exchanger 44, which is exposed to the outside air, is connected to the third heat exchanger 43 by a refrigerant line, the fourth heat exchanger 44 cannot extract heat from the outside air when the second compressor 41 is in the off state. Therefore, according to the third embodiment, the air conditioner 100 does not operate in low-outside-air cooling mode.

[0096] As in the Fig. As shown in Figures 9 to 12, the external machine 40 in the air conditioning system 100 according to the third embodiment mainly generates hot heat and the branching unit 10 generates the air conditioning capacity which corresponds to the heating capacity at the time of main cooling operation and the cooling capacity at the time of main heating operation.

[0097] If, as in Fig. As shown in Figure 9, with all indoor units 50a, 50b and 50c operating in cooling mode, the air conditioner 100 performs cooling-only operation.

[0098] As in Fig. As shown in Figure 10, the air conditioner 100 performs the main cooling operation when the cooling operation mode and the heating operation mode are operating side by side in the indoor units 50a, 50b and 50c and the total air conditioning loads of the indoor units in cooling operation mode are greater than the total air conditioning loads of the indoor units in heating operation mode.

[0099] If, as in Fig. As shown in Figure 11, all indoor units 50a, 50b and 50c are operating in heating mode, the air conditioner 100 performs heating-only operation.

[0100] As in Fig. As shown in Figure 12, the air conditioner 100 performs the main heating operation when the cooling operation mode and the heating operation mode are operating side by side in the indoor units 50a, 50b and 50c and the total air conditioning loads of the indoor units in heating operation mode are greater than the total air conditioning loads of the indoor units in cooling operation mode.

[0101] Next, the functions and effects of the air conditioning system 100 according to the third embodiment will be described.

[0102] In the air conditioning system 100 according to the first embodiment, which has the cooling tower 63, and the air conditioning system 100 according to the second embodiment, which has the ground heat exchanger 70, all of the cooling and heating capacities of the plurality of indoor units 50a, 50b and 50c in the refrigeration circuit in the branching unit 10 must be generated in cooling-only operation, in main cooling operation, in heating-only operation and in main heating operation of the air conditioning system 100.

[0103] In the air conditioning system 100 according to the third embodiment, the outdoor unit 60 has an outdoor unit 40. Therefore, the cooling capacity during cooling-only operation and the heating capacity during heating-only operation of the air conditioning system 100 can be generated in the refrigeration circuit in the outdoor unit 40. Therefore, the refrigeration circuit in the branching unit 10 can be reduced in size.

[0104] Since the refrigeration circuit in the branching unit 10 is smaller, the space required for the refrigeration circuit, the base, and the cost of the branching unit 10 can be reduced, and the vibrations and noise caused mainly by the first compressor 31 can be reduced. Furthermore, the amount of refrigerant contained in the branching unit 10 can also be reduced.

[0105] In the air conditioning system 100 according to the third embodiment, the suction volume of the second compressor 41 in the outdoor unit 40 is larger than the suction volume of the first compressor 31 in the branching unit 10. This reduces the space required for the refrigeration circuit, the footprint, and the cost of the branching unit 10, and also reduces the vibrations and noise caused by the first compressor 31. Furthermore, the amount of refrigerant contained in the branching unit 10 can also be reduced. Fourth embodiment.

[0106] The air conditioning unit 100 according to a fourth embodiment is identical to the air conditioning unit 100 according to the third embodiment with regard to configuration, operation, functions and effects, unless otherwise described.

[0107] A defrosting operation of air conditioning unit 100 according to the fourth embodiment is described with reference to Fig. 13 described. As in Fig. As shown in Figure 13, in the air conditioning system 100 according to the fourth embodiment, the defrosting operation is carried out when frost forms on the fourth heat exchanger 44 and defrosting is required in the heating-only operation or in the main heating operation.

[0108] In the air conditioning system 100 according to the fourth embodiment, the defrosting operation is carried out to remove the frost adhering to the fourth heat exchanger 44 of the outdoor unit 40. During the defrosting operation, the refrigerant flows through the second refrigerant line path R2 and the first refrigerant line path R1, as described below.

[0109] In the second refrigerant line path R2, the refrigerant flows from the second compressor 41 through the second four-way valve 48, the fourth heat exchanger 44, the second expansion valve 42, the third heat exchanger 43, and the second four-way valve 48 to return to the second compressor 41 in the outdoor unit 40. This means that the refrigeration circuit in the outdoor unit 40 forms a refrigerant circuit in which the refrigerant flows from the second compressor 41 through the second four-way valve 48, the fourth heat exchanger 44, the second expansion valve 42, the third heat exchanger 43, and the second four-way valve 48 to the second compressor 41.

[0110] In the first refrigerant line path R1, the refrigerant flows from the first compressor 31, the first four-way valve 18, the second heat exchanger 22, the first expansion valve 32, the first heat exchanger 12, and the first four-way valve 18 to return to the first compressor 31 in the branching unit 10. This means that the refrigeration circuit in the branching unit 10 forms a refrigerant circuit in which the refrigerant flows from the first compressor 31 through the first four-way valve 18, the second heat exchanger 22, the first expansion valve 32, the first heat exchanger 12, and the first four-way valve 18 to the first compressor 31.

[0111] Next, the functions and effects of the air conditioning system 100 according to the fourth embodiment will be described.

[0112] In the air conditioning system 100 according to the fourth embodiment, the defrosting operation is carried out to remove the frost adhering to the fourth heat exchanger 44 of the outdoor unit 40. Therefore, if frost forms on the fourth heat exchanger 44 and defrosting is required in heating-only mode or in main heating mode, the heating operation of the indoor units can continue and a quantity of defrosting heat can be supplied to the fourth heat exchanger 44. Fifth embodiment.

[0113] The air conditioning unit 100 according to a fifth embodiment is identical to the air conditioning unit 100 according to the third embodiment with regard to configuration, operation, functions and effects, unless otherwise described.

[0114] A configuration of an air conditioning system 100 according to the fifth embodiment is described with reference to Fig. 14 described. As in Fig. As shown in Figure 14, the branching unit 10 in the air conditioning system 100 according to the fifth embodiment has a main supply line on / off valve 34 and a main return line on / off valve 35.

[0115] The main supply line on / off valve 34 is located at a connection section between the second line path P2 and the main supply line 61 in the branching unit 10. The main supply line on / off valve 34 is configured to open and close the second line path P2 and the main supply line 61. The main return line on / off valve 35 is located at a connection section between the second line path P2 and the main return line 62 in the branching unit 10. The main return line on / off valve 35 is configured to open and close the second line path P2 and the main return line 62.

[0116] Next, the functions and effects of the air conditioning system 100 according to the fifth embodiment will be described.

[0117] In the air conditioning unit 100 according to the fifth embodiment, the supply line inlet / outlet valve 34 is arranged at the connection section between the second line path P2 and the supply line 61 in the branching unit 10. The return line inlet / outlet valve 35 is arranged at the connection section between the second line path P2 and the return line 62 in the branching unit 10. By closing the supply line inlet / outlet valve 34 and the return line inlet / outlet valve 35, a second line path P2 can therefore be formed through the branching unit 10 and the plurality of indoor units 50a, 50b, and 50c, in which the heat transfer medium is circulated by the second pump 21.

[0118] If the branching unit 10 and the outdoor machine 40 cannot be installed simultaneously, or if there is a risk of water leakage in the supply main line 61 and the return main line 62 connecting the branching unit 10 and the outdoor machine 40, a water leakage and water circulation test can only be carried out with the branching unit 10 and the multiple indoor units 50a, 50b and 50c. Sixth embodiment.

[0119] The air conditioning unit 100 according to a sixth embodiment is identical to the air conditioning unit 100 according to the first embodiment with regard to configuration, operation, functions and effects, unless otherwise described.

[0120] The configurations of the supply branch lines 51, the return branch lines 52, the supply main line 61 and the return main line 62 of the air conditioning system 100 according to the sixth embodiment are described with reference to Fig. 15 described. As in Fig. As shown in Figure 15, the inner diameter of each of the main supply line 61 and the main return line 62 is larger than the inner diameter of each of the plurality of supply branch lines 51 and the inner diameter of each of the plurality of return branch lines 52. That is, a minimum value of the inner diameters of the main supply line 61 and the main return line 62 is larger than a maximum value of the inner diameters of all supply branch lines 51 and all return branch lines 52.

[0121] Next, the functions and effects of the air conditioning system 100 according to the sixth embodiment will be described.

[0122] In the air conditioning system 100 according to the sixth embodiment, the inner diameter of each of the main supply line 61 and the main return line 62 is larger than the inner diameter of each of the plurality of supply branch lines 51 and the inner diameter of each of the plurality of return branch lines 52.

[0123] During cooling-only operation, in which the multiple indoor units 50a, 50b and 50c are all in cooling mode, or during heating-only operation, in which the multiple indoor units 50a, 50b and 50c are in heating mode, a maximum flow rate of the heat medium (water or antifreeze) flows through the supply main line 61 and the return main line 62.

[0124] Since the inner diameter of each of the supply main line 61 and the return main line 62 is larger than the inner diameter of each of the plurality of supply branch lines 51 and the inner diameter of each of the plurality of return branch lines 52, flow resistance in each of the supply main line 61 and the return main line 62 can be suppressed.

[0125] By ensuring that the internal volume of each of the supply branch lines 51 and the return branch lines 52 is not excessively large, the total volume of the heat transfer medium (water or antifreeze) retained in the air conditioning system 100 can be kept small. Therefore, the time required to demonstrate the air conditioning capacity at the start of cooling and heating operation can be reduced. This improves the traceability of the air conditioning control. Seventh embodiment.

[0126] The air conditioning unit 100 according to a seventh embodiment is identical to the air conditioning unit 100 according to the first embodiment with regard to configuration, operation, functions and effects, unless otherwise described.

[0127] In the air conditioning system 100 according to the seventh embodiment, the heat transfer medium flowing through the first conduit path P1 and the second conduit path P2 is a fluid that has a lower global warming impact per unit mass than carbon dioxide. The global warming potential per unit mass of the heat transfer medium is lower than that of carbon dioxide.

[0128] In the air conditioning system 100 according to the seventh embodiment, the global warming potential per unit mass of the heat transfer medium is lower than that of carbon dioxide. This reduces the impact on global warming or the greenhouse effect at the time of a heat transfer medium leak.

[0129] The embodiments described above can be combined as necessary.

[0130] It goes without saying that the embodiments disclosed herein are in every respect illustrative and not limiting. The scope of this disclosure is defined more by the terms of the claims than by the above description and is intended to include all modifications within the scope and meaning that correspond to the terms of the claims. REFERENCE MARK LIST

[0131] 10 Branching unit; 11 First pump; 12 First heat exchanger; 13 First branching head; 14a, 14b, 14c First supply branching line inlet / outlet valve; 15a, 15b, 15c First return branching line inlet / outlet valve; 16 First confluence head; 17 First bypass valve; 18 First four-way valve; 21 Second pump; 22 Second heat exchanger; 23 Second branching head; 24a, 24b, 24c Second supply branching line inlet / outlet valve; 25a, 25b, 25c Second return branching line inlet / outlet valve; 26 Second confluence head; 27 Second bypass valve; 31 First compressor; 32 First expansion valve; 33 Flow rate adjustment valve; 34 Supply main line inlet / outlet valve; 35 Return main line inlet / outlet valve; 40 Outdoor unit; 41 Second compressor; 42 Second expansion valve; 43 Third heat exchanger; 44 Fourth heat exchanger; 45 Outdoor fan; 48 Second four-way valve; 50a, 50b, 50c Indoor unit; 51a, 51b, 51c Supply branch line;52a, 52b, 52c Return branch line; 53a, 53b, 53c Internal heat exchanger; 54a, 54b, 54c Internal fan; 60 Outdoor unit; 61 Supply main line; 62 Return main line; 63 Cooling tower; 64 Fan; 70 Ground source heat exchanger; 100 Air conditioning unit; P1 First line path; P2 Second line path; R1 First refrigerant line path; R2 Second refrigerant line path. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2009 / 133640

[0006]

Claims

[1] Air conditioning, comprehensive: a branching unit; a large number of indoor units; an outdoor unit; a multitude of supply branch lines and a multitude of return branch lines connecting the branching unit to the respective multitude of indoor units; and a main supply line and a main return line connecting the branching unit and the outdoor unit, wherein The branching unit comprises a first branching head, a second branching head, a first confluence head, a second confluence head, a plurality of first feed branching line inlet / outlet valves, a plurality of second feed branching line inlet / outlet valves, a plurality of first return branching line inlet / outlet valves, a plurality of second return branching line inlet / outlet valves, a first bypass valve, a second bypass valve, a first pump, a second pump, a first heat exchanger, a second heat exchanger, a first compressor, a first expansion valve, and a first four-way valve arranged in the branching unit. The multitude of indoor units comprise a multitude of internal heat exchangers, each arranged within the multitude of indoor units. one end of each of the plurality of feed branch lines is connected to the first branch head by a corresponding first feed branch line on / off valve, and to the second branch head by a corresponding second feed branch line on / off valve, another end of each of the multiple supply branch lines is connected to one end of a corresponding multiple of the internal heat exchangers, one end of each of the plurality of return branch lines is connected to the first confluence headpiece by a corresponding first return branch line inlet / outlet valve, and to the second confluence headpiece by a corresponding second return branch line inlet / outlet valve, another end of each of the multiple return branch lines is connected to another end of a corresponding multiple of the interior heat exchangers, the first branch head and the first confluence head are connected to each other by the first bypass valve, the second branch headpiece and the second confluence headpiece are connected to each other by the second bypass valve, the first confluence head, the first pump, the first heat exchanger and the first branch head are connected to form a first conduit path that allows a heat medium to flow in the sequence of the first confluence head, the first pump, the first heat exchanger and the first branch head, the second confluence head, the second pump, the second heat exchanger and the second branch head are connected to form a second conduit path that allows the heat medium to flow in the sequence of the second confluence head, the second pump, the second heat exchanger and the second branch head, the first compressor, the first four-way valve, the first heat exchanger, the first expansion valve and the second heat exchanger are connected to form a first refrigerant piping path that allows refrigerant to flow, the first four-way valve is set up to be switched to cause the refrigerant to flow in the sequence of the first compressor, the first four-way valve, the first heat exchanger, the first expansion valve, the second heat exchanger and the first four-way valve, or to cause the refrigerant to flow in the sequence of the first compressor, the first four-way valve, the second heat exchanger, the first expansion valve, the first heat exchanger and the first four-way valve, one end of the main supply line is connected to one end of the outdoor unit, another end of the main supply line is connected to the second line path, one end of the return main line is connected to another end of the outdoor unit, another end of the return main line is connected to the second line path, In the first heat exchanger, heat is exchanged between the refrigerant flowing in the first refrigerant line path and the heat medium flowing in the first line path, and In the second heat exchanger, heat is exchanged between the refrigerant flowing in the first refrigerant line path and the heat medium flowing in the second line path. [2] Air conditioning system according to claim 1, wherein the branching unit comprises a flow rate adjustment valve arranged in the branching unit and in the second line path, and The flow rate adjustment valve is connected between a branch point from the main supply line and a junction point with the main return line in the second line path. [3] Air conditioning system according to claim 1 or 2, wherein the outdoor unit includes a cooling tower located in the outdoor unit, the cooling tower and the branching unit are connected to each other by the main supply line and the main return line, one end of the main supply line is connected to one end of the cooling tower, the other end of the main supply line is connected between the second pump and the second heat exchanger in the second pipe path, one end of the return main line is connected to another end of the cooling tower, and the other end of the return main line is connected between the second pump and the second heat exchanger in the second line path. [4] Air conditioning system according to claim 1 or 2, wherein The outdoor unit includes a ground-source heat exchanger located within the outdoor unit. the ground heat exchanger and the branching unit are connected to each other by the main supply line and the main return line, one end of the main supply line is connected to one end of the ground heat exchanger, the other end of the main supply line is connected between the second pump and the second heat exchanger in the second pipe path, one end of the return main line is connected to the other end of the ground heat exchanger, and the other end of the return main line is connected between the second pump and the second heat exchanger in the second line path. [5] Air conditioning system according to claim 1 or 2, wherein the outdoor unit includes an outdoor machine which is arranged in the outdoor unit, The external machine comprises a second compressor, a second four-way valve, a second expansion valve, a third heat exchanger, and a fourth heat exchanger, which are arranged in the external machine. The second compressor, the second four-way valve, the third heat exchanger, the second expansion valve, and the fourth heat exchanger are connected to form a second refrigerant line path, which allows refrigerant to flow. the external machine and the branching unit are connected to each other by the main supply line and the main return line, the second four-way valve is set up to be switched to cause the refrigerant to flow in the sequence of the second compressor, the second four-way valve, the third heat exchanger, the second expansion valve, the fourth heat exchanger and the second four-way valve, or to cause the refrigerant to flow in the sequence of the second compressor, the second four-way valve, the fourth heat exchanger, the second expansion valve, the third heat exchanger and the second four-way valve, one end of the main supply line is connected to one end of the third heat exchanger, the other end of the main supply line is connected between the second heat exchanger and the second branch headpiece in the second line path, one end of the return main line is connected to the other end of the third heat exchanger, and the other end of the return main line is connected between the second heat exchanger and the second branch headpiece in the second line path. [6] Air conditioning system according to claim 5, wherein The suction volume of the second compressor in the external machine is greater than the suction volume of the first compressor in the branching unit. [7] Air conditioning system according to claim 5 or 6, wherein A defrosting operation is carried out to remove frost adhering to the fourth heat exchanger in the outdoor unit, and during defrosting operation, In the second refrigerant line path, the refrigerant flows from the second compressor through the second four-way valve, the fourth heat exchanger, the second expansion valve, the third heat exchanger and the second four-way valve to reach the second compressor in the outdoor unit again, and In the first refrigerant line path, the refrigerant flows from the first compressor through the first four-way valve, the second heat exchanger, the first expansion valve, the first heat exchanger and the first four-way valve to reach the first compressor again in the branching unit. [8] Air conditioning system according to any one of claims 1 to 7, wherein the capacity of the second pump is greater than the capacity of the first pump. [9] Air conditioning system according to any one of claims 1 to 8, wherein The branching unit comprises a main supply line on / off valve and a main return line on / off valve. The main supply line on / off valve is arranged at a connecting section between the second line path and the main supply line in the branching unit, and the main return line on / off valve is arranged at a connecting section between the second line path and the main return line in the branching unit. [10] Air conditioning system according to any one of claims 1 to 9, wherein an inner diameter of each of the supply main line and the return main line is larger than an inner diameter of each of the plurality of supply branch lines and an inner diameter of each of the plurality of return branch lines. [11] Air conditioning system according to any one of claims 1 to 10, wherein the global warming potential per unit mass of the heat medium is less than that of carbon dioxide.

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