Air conditioning system

Abstract

To ensure a large temperature difference through efficient heat exchange with a simple configuration.SOLUTION: An air conditioning system (1) supplies conditioned air to the inside of a room in accordance with an air conditioning condition in the room. The air conditioning system is provided with an outdoor conditioner (12) that applies air conditioning processing to the outside air introduced from the outdoors and supplies the conditioned air to the inside of the room, an air conditioner (13) that applies air conditioning processing to the return air introduced from the inside of the room and supplies the conditioned air to the inside of the room, and a heat source machine (11) that supplies a heat medium to the outdoor conditioner and the air conditioner through a circulation system (14). In the circulation system, the air conditioner is connected in series downstream of the outdoor conditioner.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an air conditioning system. Background Art

[0002] Conventionally, an air conditioning system including an outdoor air conditioner and an indoor air conditioner is known (see, for example, Patent Document 1). The air conditioning system described in Patent Document 1 is provided with a heat source apparatus that produces medium-temperature cold water and low-temperature cold water, and cold water lines for medium-temperature cold water and low-temperature cold water extend from the heat source apparatus to the outdoor air conditioner and the indoor air conditioner, respectively. The supply states of the medium-temperature cold water and low-temperature cold water to the outdoor air conditioner and the indoor air conditioner are switched according to a cooling load or the like. In the outdoor air conditioner, outdoor air introduced from outside is subjected to air conditioning treatment and then supplied indoors, and in the indoor air conditioner, return air introduced from the room is subjected to air conditioning treatment and then supplied indoors. Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Unexamined Patent Publication No. 2019-124396 Summary of the Invention Problems to be Solved by the Invention

[0004] However, in the air conditioning system described in Patent Document 1, the configuration is complicated because the heat source apparatus that produces medium-temperature cold water and low-temperature cold water and the corresponding piping paths are required. In addition, since cold water is individually supplied from the heat source apparatus to the outdoor air conditioner and the indoor air conditioner, there is room for improvement in terms of energy saving.

[0005] The present invention has been made in view of this point, and an object of the present invention is to provide an air conditioning system that can achieve energy saving by effectively utilizing a heat medium with a simple configuration. Means for Solving the Problems

[0006] An air conditioning system according to one aspect of the present invention is an air conditioning system that supplies conditioned air into a room according to the indoor air conditioning conditions, comprising: an outdoor air handling unit that applies air conditioning treatment to outside air introduced from the outdoors and supplies it to the room; an air conditioning unit that applies air conditioning treatment to return air introduced from the room and supplies it to the room; and a heat source unit that supplies a heat transfer medium to the outdoor air handling unit and the air conditioning unit through a circulation system. A first transfer pump that sends a heat transfer medium from the heat source unit to the air handling unit, a second transfer pump that sends a heat transfer medium from the air handling unit to the air conditioner, a first flow control valve that dynamically controls the flow rate of the heat transfer medium passing through the air handling unit, and a second flow control valve that dynamically controls the flow rate of the heat transfer medium passing through the air conditioner. The system is equipped with the air conditioner connected in series downstream of the external air handling unit in the circulation system. The opening degree of the first flow control valve and the transport power of the first transport pump are adjusted according to the discharge temperature of the air handling unit, and the opening degree of the second flow control valve and the transport power of the second transport pump are adjusted according to the room temperature. [Effects of the Invention]

[0007] In one aspect of the present invention, an air conditioning system is configured such that a heat transfer medium supplied from a heat source unit and outside air introduced from the outdoors exchange heat in an air handling unit, and the heat transfer medium that has passed through the air handling unit and return air introduced from the indoors exchange heat in an air conditioner. By sending the heat transfer medium from the air handling unit to the air conditioner, the waste heat generated during the air conditioning process of the air handling unit is utilized in the air conditioning process of the air conditioner. As a result, the heat transfer medium is effectively utilized, leading to energy savings in the air conditioning system. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of the air conditioning system according to the first embodiment. [Figure 2] This is a schematic diagram of the air conditioning system according to the second embodiment. [Figure 3] This is a schematic diagram of the air conditioning system in Comparative Example 1. [Figure 4] This is a schematic diagram of the air conditioning system in Comparative Example 2. [Modes for carrying out the invention]

[0009] <Comparative Example 1> First, before describing the air conditioning system of the first embodiment, we will describe the air conditioning system of Comparative Example 1. Figure 3 is a schematic diagram of the air conditioning system of Comparative Example 1. Furthermore, the air conditioning conditions, temperature, humidity, etc. described below are examples only, and the air conditioning conditions, temperature, humidity, etc. can be changed as appropriate depending on the situation.

[0010] As shown in Figure 3, in the air conditioning system 90 of Comparative Example 1, the heat source unit 91, the air handling unit 92, and the air conditioner 93 are connected via a circulation system 94 for a heat transfer medium such as chilled or hot water. Downstream of the heat source unit 91, the flow path branches into two, with the air handling unit 92 installed in one flow path and the air conditioner 93 installed in the other flow path. Furthermore, the air conditioning system 90 employs a latent heat-sensible heat separation method, where the air handling unit 92 performs latent heat treatment on the outside air introduced from outdoors, and the air conditioner 93 performs sensible heat treatment on the return air introduced from indoors. The conditioned air after treatment is supplied to the room from the air handling unit 92 and the air conditioner 93 through an air supply system (not shown).

[0011] When this air conditioning system 90 is in cooling mode, the indoor air conditioning conditions are set to a temperature of 26°C and a humidity of 50%. A heat transfer medium at 7°C is sent from the heat source unit 91 to the outdoor air handling unit 92 and the air conditioner 93. The outdoor air handling unit 92 produces conditioned air with a supply temperature of 13°C and humidity of 90% from outside air at a temperature of 35°C, and the air conditioner 93 produces conditioned air with a supply temperature of 17°C and humidity of 90% from return air at a temperature of 26°C. Because the temperature difference between the inlet and outlet of the outdoor air handling unit 92 and the air conditioner 93 is set to 5°C, a heat transfer medium at 12°C is returned from the outdoor air handling unit 92 and the air conditioner 93 to the heat source unit 91. As a result, the temperature difference between the supply and return of the heat transfer medium is 5°C, making it impossible to secure a large temperature difference.

[0012] By the way, the required temperature of the heat transfer medium differs between the latent heat treatment of the outdoor air handling unit 92 and the sensible heat treatment of the air conditioner 93. In the outdoor air handling unit 92, simply lowering the temperature of the outside air is not enough to dehumidify it. In order to lower the temperature of the outside air to 13°C, which is below the indoor dew point temperature, it is necessary to send a heat transfer medium at 7°C (low temperature) from the heat source unit 91 to the outdoor air handling unit 92. On the other hand, in the air conditioner 93, it is sufficient to adjust the supply temperature of the return air to 17°C, which is higher than the indoor dew point temperature. In order to lower the supply temperature of the return air to 17°C, it is not necessary to send a heat transfer medium at 7°C from the heat source unit 91 to the air conditioner 93. In the air conditioner 93, the supply temperature of the return air can be lowered to 17°C even with a heat transfer medium of 7°C or higher (medium temperature).

[0013] As described above, since the temperature difference between the inlet and outlet of the air handling unit 92 is 5°C, a heat transfer medium at 12°C is discharged from the air handling unit 92, and even with this 12°C heat transfer medium, the air conditioner 93 can adjust the supply air temperature of the return air to 17°C. Therefore, in the first embodiment, unlike the idea of ​​individually realizing latent heat-sensible heat separation air conditioning and large temperature difference air conditioning in the air handling unit 12 and the air conditioner 13, attention is focused on the fact that the heat transfer medium after latent heat treatment has the potential to undergo sensible heat treatment, and latent heat-sensible heat separation air conditioning and large temperature difference air conditioning are realized in the air conditioning system 1 while utilizing the heat transfer medium after latent heat treatment in the air conditioner 13 for sensible heat treatment (see Figure 1). This eliminates the need to provide multiple heat source units, prevents complexity of piping routes, and allows for effective utilization of the heat transfer medium. In other words, latent heat-sensible heat separation air conditioning and large temperature difference air conditioning can be realized with a simple configuration.

[0014] <First Embodiment> The air conditioning system of the first embodiment will be described in detail below with reference to the attached drawings. Figure 1 is a schematic diagram of the air conditioning system of the first embodiment. In the following description, we will explain the air conditioning during cooling, but the same applies to the air conditioning during heating.

[0015] As shown in Figure 1, the air conditioning system 1 is provided with a circulation system 14 through which a heat transfer medium circulates from the heat source unit 11 to the heat source unit 11 via the outdoor air handling unit 12 and the air conditioner 13. The heat transfer medium is supplied from the heat source unit 11 to the outdoor air handling unit 12 and the air conditioner 13 through the circulation system 14. As the heat transfer medium passes through the outdoor air handling unit 12 and the air conditioner 13, the outdoor air handling unit 12 treats the outside air, and the air conditioner 13 treats the return air. In the air conditioning system 1, conditioned air, such as the treated outside air and return air, is supplied to the room from the outdoor air handling unit 12 and the air conditioner 13 through a supply air system (not shown) according to the indoor air conditioning conditions such as temperature and humidity.

[0016] An air handling unit 12 is provided with a supply air fan (not shown) and a heat exchange coil (not shown). Outside air is introduced from the outdoors into the air handling unit 12 by the supply air fan, and the outside air is cooled by heat exchange between the outside air and a heat medium passing through the heat exchange coil. An air conditioner 13 is also provided with a supply air fan and a heat exchange coil, and has substantially the same configuration as the air handling unit 12. In the air handling unit 12, latent heat treatment is performed on the outside air as air conditioning treatment, and in the air conditioner 13, sensible heat treatment is performed on return air as air conditioning treatment. The outside air is cooled and dehumidified by the latent heat treatment of the air handling unit 12 and supplied into the room, and the return air is cooled by the sensible heat treatment of the air conditioner 13 and supplied into the room.

[0017] A circulation system 14 is provided with first main flow paths 21A, 21B connecting a heat source device 11 and the air handling unit 12, second main flow paths 22A, 22B connecting the air handling unit 12 and the air conditioner 13, and third main flow paths 23A, 23B connecting the air conditioner 13 and the heat source device 11. Headers 25A, 25B are provided between the first main flow paths 21A, 21B, and a first delivery pump 31 is provided between the headers 25A, 25B. Headers 25C, 25D are provided between the second main flow paths 22A, 22B, and a second delivery pump 32 is provided between the headers 25C, 25D. A header 25E is provided between the third main flow paths 23A, 23B, and a third delivery pump 33 is provided downstream of the header 25E.

[0018] The heat medium is delivered from the heat source device 11 to the air handling unit 12 by the first delivery pump 31, the heat medium is delivered from the air handling unit 12 to the air conditioner 13 by the second delivery pump 32, and the heat medium is delivered from the air conditioner 13 to the heat source device 11 by the third delivery pump 33. The header 25B and the header 25C are connected via a first bypass flow path 27, and the header 25C and the header 25E are connected via a second bypass flow path 28. The first bypass flow path 27 allows the heat medium to bypass the air handling unit 12, and the second bypass flow path 28 allows the heat medium to bypass the air conditioner 13.

[0019] A first flow control valve 35 is provided near the outlet of the outdoor air conditioning unit 12, and the flow rate of the heat medium passing through the outdoor air conditioning unit 12 is controlled by the first flow control valve 35. A dew point thermometer 41 is provided near the outlet of the outdoor air conditioning unit 12, and the opening degree of the first flow control valve 35 is adjusted in accordance with the outlet temperature of the outdoor air conditioning unit 12 measured by the dew point thermometer 41. When the outlet temperature approaches a target temperature, the opening degree of the first flow control valve 35 is reduced to limit the flow rate. A first pressure gauge 45 is provided on the header 25B, and the conveying power of a first conveying pump 31 is adjusted in accordance with a pressure increase in the flow path detected by the first pressure gauge 45.

[0020] A second flow control valve 36 is provided near the outlet of the air conditioner 13, and the flow rate of the heat medium passing through the air conditioner 13 is controlled by the second flow control valve 36. An indoor thermometer 43 is connected to the air conditioner 13, and the opening degree of the second flow control valve 36 is adjusted in accordance with the indoor temperature measured by the indoor thermometer 43. When the indoor temperature approaches a target temperature, the opening degree of the second flow control valve 36 is reduced to control the flow rate. A second pressure gauge 46 is provided on the header 25D, and the conveying power of a second conveying pump 32 is adjusted in accordance with a pressure increase in the flow path detected by the second pressure gauge 46.

[0021] As the first and second conveying pumps 31 and 32, inverter pumps capable of changing the conveying amount of the heat medium are used. When the opening degrees of the first and second flow control valves 35 and 36 decrease, pressure increases in the first and second main flow paths 21B and 22B are detected by the first and second pressure gauges 45 and 46. Based on the pressure increases detected by the first and second pressure gauges 45 and 46, the conveying power of the first and second conveying pumps 31 and 32 is reduced, thereby suppressing the supply of the heat medium to the outdoor air conditioning unit 12 and the air conditioner 13. There is a limit to the adjustment amount of the conveying power (pump rotation speed) of the first and second conveying pumps 31 and 32, and the conveying power of the first and second conveying pumps 31 and 32 cannot be reduced below a certain level.

[0022] A first bypass valve 47 is provided in the first bypass passage 27. When a pressure increase is detected even when the transport power of the first transport pump 31 has dropped to its limit, the first bypass valve 47 opens and the heat transfer medium is released into the first bypass passage 27. Between the headers 25C and 25D, a second bypass valve 48 is provided in parallel with the second transport pump 32. When a pressure increase is detected even when the transport power of the second transport pump 32 has dropped to its limit, the second bypass valve 48 opens and the heat transfer medium is released into the second bypass passage 28 through the headers 25D and 25C. The second bypass passage 28 is what is known as a free passage.

[0023] In the circulation system 14, an air conditioner 13 is connected in series downstream of the air handling unit 12. More specifically, the outlet of the heat exchange coil of the air handling unit 12 is connected to the inlet of the heat exchange coil of the air conditioner 13 through the second main flow paths 22A and 22B. Since a low-temperature (e.g., 7°C) heat transfer medium is supplied to the air handling unit 12 from the heat source unit 11, heat exchange occurs between the low-temperature heat transfer medium passing through the heat exchange coil of the air handling unit 12 and the outside air, cooling and dehumidifying the outside air. Since a medium-temperature (e.g., 12°C) heat transfer medium that has passed through the air handling unit 12 is supplied to the air conditioner 13, heat exchange occurs between the medium-temperature heat transfer medium passing through the heat exchange coil of the air conditioner 13 and the return air, cooling the return air.

[0024] As described above, the outdoor air handling unit 12 needs to cool the outside air to below the indoor dew point temperature, but the air conditioner 13 only needs to cool the return air to below the indoor set temperature. Since the temperature of the heat medium required for sensible heat treatment is higher than the temperature of the heat medium required for latent heat treatment, the temperature of the heat medium after latent heat treatment by the outdoor air handling unit 12 can be used to perform sensible heat treatment on the return air in the air conditioner 13. Furthermore, since the heat medium after latent heat treatment is also used for sensible heat treatment, a large temperature difference is ensured between the return and recirculation of the heat medium. In this way, the air conditioning system 1 of this embodiment realizes latent heat and sensible heat separation air conditioning and large temperature difference air conditioning.

[0025] Specifically, when the air conditioning system 1 is cooling, the indoor air conditioning conditions are set to a temperature of 26°C and a humidity of 50%. A heat transfer medium at 7°C is sent from the heat source unit 11 to the outdoor air handling unit 12. In the outdoor air handling unit 12, latent heat is treated on the outside air through heat exchange between the 7°C heat transfer medium and the outside air, and conditioned air with a supply temperature of 13°C and humidity of 90% is produced from the outside air at a temperature of 35°C and supplied to the room. Since the temperature difference between the inlet and outlet of the outdoor air handling unit 12 is set to 5°C, the heat transfer medium rises from 7°C to 12°C as it passes through the outdoor air handling unit 12, and the 12°C heat transfer medium is sent from the outlet of the outdoor air handling unit 12 towards the air conditioner 13.

[0026] In the air conditioner 13, the return air is treated with sensible heat through heat exchange between the 12°C heat transfer medium and the return air. This process creates conditioned air with a supply temperature of 17°C and humidity of 90% from the 26°C return air, which is then supplied to the room. Since the temperature difference between the inlet and outlet of the air conditioner 13 is set to 5°C, the heat transfer medium rises from 12°C to 17°C as it passes through the air conditioner 13, and the 17°C heat transfer medium is returned from the outlet of the air conditioner 13 to the heat source unit 11. As a result, the temperature difference between the heat transfer medium going from the heat source unit 11 to the outdoor air handling unit 12 and the heat transfer medium returning from the air conditioner 13 to the heat source unit 11 is 10°C, ensuring a large temperature difference throughout the entire system.

[0027] As described above, according to the air conditioning system 1 of the first embodiment, the heat transfer medium supplied from the heat source unit 11 and the outside air introduced from outside are heat-exchanged in the outdoor air handling unit 12, and the heat transfer medium that has passed through the outdoor air handling unit 12 and the return air introduced from inside the room are heat-exchanged in the air conditioner 13. By sending the heat transfer medium from the outdoor air handling unit 12 to the air conditioner 13, the waste heat generated in the air conditioning process of the outdoor air handling unit 12 is utilized in the air conditioning process of the air conditioner 13. Therefore, the heat transfer medium is effectively utilized, and energy saving of the air conditioning system is achieved. In addition, by ensuring a large temperature difference between the supply and return of the heat transfer medium, the amount of heat required by the air conditioning system 1 can be maintained even if the flow rate of the heat transfer medium is reduced. Therefore, the pipe diameter and transport power of the circulation system 14 can be reduced. Furthermore, existing equipment can be used for the heat source unit 11, outdoor air handling unit 12, air conditioner 13, etc.

[0028] <Comparative Example 2> Next, before describing the air conditioning system of the second embodiment, we will describe the air conditioning system of Comparative Example 2. Figure 4 is a schematic diagram of the air conditioning system of Comparative Example 2.

[0029] As shown in Figure 4, the air conditioning system 100 of Comparative Example 2 is compatible with multiple rooms. In the air conditioning system 100, the flow path branches into four downstream of the heat source unit 101. The first air handling unit 102A is installed in the first flow path, the first air conditioner 103A is installed in the second flow path, the second air handling unit 102B is installed in the third flow path, and the second air conditioner 103B is installed in the fourth flow path. Latent heat treatment is performed on the outside air by the first and second air handling units 102A and 102B, and sensible heat treatment is performed on the return air by the first and second air conditioners 103A and 103B. Air-conditioned air is supplied to two rooms from the first and second air handling units 102A and 102B and the first and second air conditioners 103A and 103B through an air supply system (not shown).

[0030] During cooling operation of this air conditioning system 100, the air conditioning conditions in one room are set to a set temperature of 26°C and a humidity of 50%, while the air conditioning conditions in the other room are set to a set temperature of 23°C and a humidity of 50%. A heat transfer medium at 7°C is supplied from the heat source unit 101 to the first and second outdoor air handling units 102A and 102B, and the first and second air conditioners 103A and 103B. The first outdoor air handling unit 102A produces conditioned air with a supply air temperature of 13°C and a humidity of 90% from outside air at a temperature of 35°C, and the first air conditioner 103A produces conditioned air with a supply air temperature of 17°C and a humidity of 90% from return air at a temperature of 26°C. The second air handling unit 102B produces conditioned air with a supply air temperature of 9°C and humidity of 90% from outside air at a temperature of 35°C, and the second air conditioner 103B produces conditioned air with a supply air temperature of 14°C and humidity of 90% from return air at a temperature of 23°C.

[0031] Since the temperature difference between the inlet and outlet of the first air handling unit 102A and the first air conditioner 103A is set to 5°C, a heat transfer medium at 12°C is returned from the first air handling unit 102A and the first air conditioner 103A to the heat source unit 101. Since the temperature difference between the inlet and outlet of the second air handling unit 102B and the second air conditioner 103B is set to 5°C, a heat transfer medium at 12°C is returned from the second air handling unit 102B and the second air conditioner 103B to the heat source unit 101. In the air conditioning system 100 of Comparative Example 2, conditioned air is supplied to each room according to the air conditioning conditions of each room, but the heat transfer medium is not effectively utilized, and the temperature difference between the supply and return of the heat transfer medium is 5°C, making it impossible to secure a large temperature difference. Therefore, in the air conditioning system 50 of the second embodiment, the waste heat generated by the latent heat treatment of the multiple air handling units is used for the sensible heat treatment of the multiple air conditioners to secure a large temperature difference throughout the entire system.

[0032] <Second Embodiment> The air conditioning system of the second embodiment will now be described in detail with reference to the attached drawings. Figure 2 is a schematic diagram of the air conditioning system of the second embodiment. Note that the air conditioning system of the second embodiment differs from the air conditioning system of the first embodiment in that it controls the air conditioning of multiple rooms. Therefore, in the case of the second embodiment, explanations of configurations similar to those of the first embodiment will be omitted as much as possible.

[0033] As shown in Figure 2, the air conditioning system 50 is provided with a circulation system 54 through which a heat transfer medium circulates from the heat source unit 51 to the heat source unit 51, passing through the first and second outdoor air handling units 52A, 52B and the first and second air conditioners 53A, 53B. As the heat transfer medium passes through the first and second outdoor air handling units 52A, 52B and the first and second air conditioners 53A, 53B, latent heat treatment is applied to the outside air in the first and second outdoor air handling units 52A, 52B, and sensible heat treatment is applied to the return air in the first and second air conditioners 53A, 53B. In the air conditioning system 50, conditioned air is supplied to two rooms from the first and second outdoor air handling units 52A, 52B and the first and second air conditioners 53A, 53B through an air supply system (not shown).

[0034] Upstream of the first and second air handling units 52A and 52B, the first main flow path 61B branches into two, and downstream of the first and second air handling units 52A and 52B, the second main flow path 62A branches into two. One of the first main flow paths 61B is connected to the inlet of the first air handling unit 52A, and one of the second main flow paths 62A is connected to the outlet of the first air handling unit 52A. The other of the first main flow path 61B is connected to the inlet of the second air handling unit 52B, and the other of the second main flow path 62A is connected to the outlet of the second air handling unit 52B. In the circulation system 54, a first parallel flow path 58 is formed by connecting the first and second air handling units 52A and 52B in parallel.

[0035] Upstream of the first and second air conditioners 53A and 53B, the second main flow path 62B branches into two, and downstream of the first and second air conditioners 53A and 53B, the third main flow path 63A branches into two. One of the flow paths of the second main flow path 62B is connected to the inlet of the first air conditioner 53A, and one of the flow paths of the third main flow path 63A is connected to the outlet of the first air conditioner 53A. The other flow path of the second main flow path 62B is connected to the inlet of the second air conditioner 53B, and the other flow path of the third main flow path 63A is connected to the outlet of the second air conditioner 53B. In the circulation system 54, a second parallel flow path 59 is formed by connecting the first and second air conditioners 53A and 53B in parallel.

[0036] Header 65A and 65B are provided between the first main flow paths 61A and 61B, and a first transport pump 71 is provided between headers 65A and 65B. Header 65C and 65D are provided between the second main flow paths 62A and 62B, and a second transport pump 72 is provided between headers 65C and 65D. Header 65E is provided between the third main flow paths 63A and 63B, and a third transport pump 73 is provided downstream of header 65E. Header 65B and header 65C are connected via a first bypass flow path 67, and header 65C and header 65E are connected via a second bypass flow path 68.

[0037] First and second flow control valves 75A and 75B are provided near the outlets of the first and second air handling units 52A and 52B, and first and second dew point thermometers 81A and 81B are provided near the air outlets of the first and second air handling units 52A and 52B. Third and fourth flow control valves 76A and 76B are provided near the outlets of the first and second air conditioners 53A and 53B, and first and second indoor thermometers 83A and 83B are connected to the first and second air conditioners 53A and 53B. A first pressure gauge 85 is provided in header 65B, and a second pressure gauge 86 is provided in header 65D. A first bypass valve 87 is provided in the first bypass passage 67, and a second bypass valve 88 is provided in parallel with the second transport pump 72 between headers 65C and 65D.

[0038] In the second embodiment as well, when the temperatures detected by the first and second dew point thermometers 81A, 81B and the first and second room thermometers 83A, 83B approach the target temperature, the flow rate of the second and third main passages 62A, 63A is limited by the first to fourth flow control valves 75A, 75B, 76A, 76B. Based on the pressure rise of the first and second pressure gauges 85, 86, the transport power of the first and second transport pumps 71, 72 is reduced, thereby suppressing the supply of the heat transfer medium to the first and second air handling units 52A, 52B and the first and second air conditioners 53A, 53B. When the transport power of the first and second transport pumps 71, 72 reaches its limit for flow rate adjustment, the first and second bypass valves 87, 88 are opened, and the heat transfer medium is released into the first and second bypass passages 67, 68.

[0039] In the circulation system 54, a second parallel flow path 59 is connected in series downstream of the first parallel flow path 58. The outlets of the heat exchange coils of the first and second air handling units 52A and 52B are connected to the inlets of the heat exchange coils of the first and second air conditioners 53A and 53B through the second main flow paths 62A and 62B. Low-temperature heat transfer fluid is supplied to the first and second air handling units 52A and 52B from the heat source unit 51, and medium-temperature heat transfer fluid, which has passed through the first and second air handling units 52A and 52B, is supplied to the first and second air conditioners 53A and 53B. In the air conditioning system 50 of the second embodiment, a large temperature difference is ensured in the return and recirculation of the heat transfer fluid by using the heat transfer fluid after latent heat treatment for sensible heat treatment as well.

[0040] Specifically, when the air conditioning system 50 is cooling, the air conditioning conditions in one room are set to a set temperature of 26°C and a humidity of 50%, while the air conditioning conditions in the other room are set to a set temperature of 23°C and a humidity of 50%. A heat transfer medium at 7°C is supplied from the heat source unit 51 to the first and second air handling units 52A and 52B. In the first air handling unit 52A, the outside air is subjected to latent heat treatment through heat exchange between the 7°C heat transfer medium and the outside air, producing conditioned air with a supply air temperature of 13°C and a humidity of 90% from the outside air at a temperature of 35°C, and is supplied to one of the rooms. In the second air handling unit 52B, the outside air is subjected to latent heat treatment through heat exchange between the 7°C heat transfer medium and the outside air, producing conditioned air with a supply air temperature of 9°C and a humidity of 90% from the outside air at a temperature of 35°C, and is supplied to the other room.

[0041] The temperature difference between the inlet and outlet of the first and second outdoor air handling units 52A and 52B is set to 5°C. As a result, the heat transfer medium rises from 7°C to 12°C as it passes through the first and second outdoor air handling units 52A and 52B, and the 12°C heat transfer medium is sent from the outlets of the first and second outdoor air handling units 52A and 52B to the first and second air conditioners 53A and 53B. In the first air conditioner 53A, the return air is subjected to sensible heat treatment through heat exchange between the 12°C heat transfer medium and the return air, and conditioned air with a supply air temperature of 17°C and humidity of 90% is produced from the return air at a temperature of 26°C and supplied to one room. In the second air conditioner 53B, the return air is subjected to sensible heat treatment through heat exchange between the 12°C heat transfer medium and the return air, and conditioned air with a supply air temperature of 14°C and humidity of 90% is produced from the return air at a temperature of 23°C and supplied to the other room.

[0042] The temperature difference between the inlet and outlet of the first and second air conditioners 53A and 53B is set to 5°C. As a result, the heat transfer medium rises from 12°C to 17°C as it passes through the first and second air conditioners 53A and 53B, and the 17°C heat transfer medium is returned from the outlets of the first and second air conditioners 53A and 53B to the heat source unit 51. In this way, the heat transfer medium is supplied in parallel from the heat source unit 51 to the first and second air handling units 52A and 52B, and then supplied in parallel to the first and second air conditioners 53A and 53B, so that air conditioning treatment is applied in parallel to the outside air and return air in each room. Furthermore, the temperature difference between the heat transfer medium flowing from the heat source unit 51 to the first and second air handling units 52A and 52B and the heat transfer medium returning from the first and second air conditioning units 53A and 53B to the heat source unit 51 is 10°C, ensuring a large temperature difference throughout the entire system.

[0043] As described above, according to the air conditioning system 50 of the second embodiment, even if the required air conditioning conditions differ in each room, the first and second outdoor air handling units 52A and 52B and the first and second air conditioners 53A and 53B supply conditioned air to each room according to the air conditioning conditions. The waste heat generated by the latent heat treatment of the first and second outdoor air handling units 52A and 52B is used in the sensible heat treatment of the first and second air conditioners 53A and 53B, so that a large temperature difference can be secured in the heat source unit 51.

[0044] In the first and second embodiments, the air handling unit applies latent heat treatment to the outside air, but the air handling unit only needs to apply air conditioning treatment to the outside air. Also, in the embodiments where the air conditioner applies sensible heat treatment to the return air, the air conditioner only needs to apply air conditioning treatment to the return air.

[0045] Furthermore, in the second embodiment, the air conditioning system is provided with a first and second air handling unit and a first and second air conditioner, but the air conditioning system may be provided with three or more air handling units and three or more air conditioners.

[0046] As described above, the first embodiment is an air conditioning system (1) that supplies conditioned air to a room according to the indoor air conditioning conditions, comprising: an outdoor air handling unit (12) that applies air conditioning treatment to outside air introduced from the outdoors and supplies it to the room; an air conditioner (13) that applies air conditioning treatment to return air introduced from the room and supplies it to the room; and a heat source unit (11) that supplies a heat transfer medium to the outdoor air handling unit and the air conditioner through a circulation system (14), wherein the air conditioner is connected in series downstream of the outdoor air handling unit in the circulation system. With this configuration, the heat transfer medium supplied from the heat source unit and the outside air introduced from the outdoors exchange heat in the outdoor air handling unit, and the heat transfer medium that has passed through the outdoor air handling unit and the return air introduced from the room exchange heat in the air conditioner. As the heat transfer medium is sent from the outdoor air handling unit to the air conditioner, the waste heat generated in the air conditioning treatment of the outdoor air handling unit is utilized in the air conditioning treatment of the air conditioner. Therefore, the heat transfer medium is effectively utilized, and energy saving of the air conditioning system is achieved.

[0047] In the second embodiment, as in the first embodiment, the outdoor air handling unit performs latent heat treatment on the outside air as part of the air conditioning process, and the air conditioner performs sensible heat treatment on the return air as part of the air conditioning process. With this configuration, the outdoor air handling unit needs to cool the outside air to below the indoor dew point temperature, but the air conditioner only needs to cool the return air to below the indoor set temperature. Since the temperature of the heat medium required for sensible heat treatment is higher than the temperature of the heat medium required for latent heat treatment, the temperature of the heat medium after latent heat treatment can be used to perform sensible heat treatment on the return air.

[0048] The third embodiment is a configuration of the second embodiment, comprising: a first transfer pump (31) that sends a heat transfer medium from a heat source unit to an air handling unit; a second transfer pump (32) that sends a heat transfer medium from the air handling unit to an air conditioner; a third transfer pump (33) that sends a heat transfer medium from the air conditioner to a heat source unit; a first flow control valve (35) that dynamically controls the flow rate of the heat transfer medium passing through the air handling unit; and a second flow control valve (36) that dynamically controls the flow rate of the heat transfer medium passing through the air conditioner. The opening of the first flow control valve and the transfer power of the first transfer pump are adjusted according to the outlet temperature of the air handling unit, and the opening of the second flow control valve and the transfer power of the second transfer pump are adjusted according to the room temperature. With this configuration, when the air conditioning load decreases, the openings of the first and second flow control valves decrease, and the transfer power of the second transfer pump is suppressed.

[0049] The fourth aspect is the third aspect, in which the circulation system is provided with a first bypass channel (27) that directs the heat transfer medium away from the air handling unit and a second bypass channel (28) that directs the heat transfer medium away from the air conditioner. With this configuration, when the transport power limit of the first transport pump is reached, the heat transfer medium can be released into the first bypass channel, and when the transport power limit of the second transport pump is reached, the heat transfer medium can be released into the second bypass channel.

[0050] The fifth embodiment is one of the embodiments of the first to fourth embodiments in which conditioned air is supplied to each of the multiple rooms according to the air conditioning conditions of each room, and the outdoor air handling unit is a plurality of outdoor air handling units (first and second outdoor air handling units 52A, 52B) that treat outside air and supply it to each room, and the air conditioners are a plurality of air conditioners (first and second air conditioners 53A, 53B) that treat return air and supply it to each room. With this configuration, even if the air conditioning conditions required for the multiple rooms are different, conditioned air according to the air conditioning conditions is supplied to each room by the plurality of outdoor air handling units and the plurality of air conditioners. The waste heat generated by the air conditioning treatment of the plurality of outdoor air handling units is used in the air conditioning treatment of the plurality of air conditioners, and a large temperature difference can be secured in the heat source unit.

[0051] The sixth aspect is a configuration in which, in the fifth aspect, the circulation system has a first parallel flow path (58) in which a plurality of outdoor air handling units are connected in parallel, and a second parallel flow path (59) in which a plurality of air conditioners are connected in parallel, and the second parallel flow path (59) is connected in series downstream of the first parallel flow path. With this configuration, after the heat transfer medium is supplied in parallel from the heat source unit to the plurality of outdoor air handling units, the heat transfer medium is supplied in parallel to the plurality of air conditioners, and air conditioning treatment can be applied in parallel to the outside air and return air in each room.

[0052] Although this embodiment and its modifications have been described, other embodiments may also be combinations of the above embodiment and its modifications, either entirely or partially.

[0053] Furthermore, the technology of the present invention is not limited to the embodiments described above, and may be modified, substituted, or transformed in various ways without departing from the spirit of the technical idea. Moreover, if the technical idea can be realized in a different way by advances in the technology or by other derived technologies, it may be implemented by that method. Accordingly, the claims cover all embodiments that may fall within the scope of the technical idea. [Explanation of Symbols]

[0054] 1. 50: Air conditioning system 11, 51: Heat source machine 12:Outside control machine 13:Air conditioner 14, 54: Circulatory system 27, 67: First bypass channel 28, 68: Second bypass channel 31, 71: First conveying pump 32, 72: Second conveying pump 33, 73: Third conveying pump 52A: First air handling unit (multiple air handling units) 52B: Second air handling unit (multiple air handling units) 53A: First air conditioner (multiple air conditioners) 53B: Second air conditioner (multiple air conditioners) 58: First parallel channel 59: Second parallel channel

Claims

1. An air conditioning system that supplies conditioned air to a room according to the indoor air conditioning conditions, An outdoor air handling unit that takes in outside air from the outdoors, applies air conditioning treatment to it, and supplies it to the room. An air conditioner that applies air conditioning treatment to the return air introduced from inside the room and supplies it to the room, A heat source unit that supplies a heat transfer medium to the aforementioned air handling unit and the aforementioned air conditioner through a circulation system, A first transfer pump that sends a heat transfer medium from the heat source unit to the air handling unit, A second transfer pump that sends a heat transfer medium from the external air handling unit to the air conditioner, A first flow control valve that dynamically controls the flow rate of the heat transfer medium passing through the external air handling unit, The system includes a second flow control valve that dynamically controls the flow rate of the heat transfer medium passing through the air conditioner, In the aforementioned circulation system, the air conditioner is connected in series downstream of the external air handling unit. The opening degree of the first flow control valve and the transport power of the first transport pump are adjusted according to the discharge temperature of the external air handling unit. An air conditioning system characterized in that the opening degree of the second flow control valve and the transport power of the second transport pump are adjusted according to the room temperature.

2. The aforementioned air handling unit performs latent heat treatment on the outside air as part of its air conditioning process. The air conditioning system according to claim 1, characterized in that the air conditioner applies sensible heat treatment to the return air as part of the air conditioning process.

3. The air conditioning system according to claim 1, characterized in that the circulation system is provided with a first bypass channel that directs the heat transfer medium to bypass the air handling unit, and a second bypass channel that directs the heat transfer medium to bypass the air conditioner.

4. Air-conditioned air is supplied to each room according to the air conditioning conditions of multiple rooms. The aforementioned air handling unit is a plurality of air handling units that treat outside air with air conditioning and supply it to each room. The air conditioning system according to any one of claims 1 to 3, characterized in that the air conditioners are a plurality of air conditioners that treat the return air with air conditioning and supply it to each room.

5. The circulation system includes a first parallel flow path in which the plurality of outdoor air handling units are connected in parallel, and a second parallel flow path in which the plurality of air conditioners are connected in parallel. The air conditioning system according to claim 4, characterized in that the second parallel flow path is connected in series downstream of the first parallel flow path.

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