Air-conditioning device and method for controlling air-conditioning device

Abstract

[Problem] To provide an air-conditioning device that is capable of handling a peak time of load and that is capable of performing an energy-saving operation at a time other than the peak time. [Solution] An air-conditioning device 1 comprises: a latent heat unit 10 that has a latent heat coil 11 and a latent heat blower 12 for sending, to an air-conditioning space, air that has been temperature-regulated by the latent heat coil 11; a sensible heat unit 20 that has a sensible heat coil 21 and a sensible heat blower 22 for sending, to the air-conditioning space, air that has been temperature-regulated by the sensible heat coil 21; an air-blowing unit 30 that has an air-blowing blower 32 for sending air to the air-conditioning space; and a control unit 42 that operates one or more units among the latent heat unit 10, the sensible heat unit 20, and the air-blowing unit 30.

Description

Air conditioner and method for controlling air conditioner

[0001] The present invention relates to an air conditioner or the like that adjusts the temperature of air, etc.

[0002] Conventional air conditioners perform all of the functions of air blowing, temperature regulation, and humidity regulation in a single unit (see, for example, Patent Document 1). In such air conditioners, the maximum output is set so that the target temperature and humidity can be achieved even during peak load times, such as when many people are present in the air-conditioned space in midsummer, and therefore large energy-consuming fans and coils are used.

[0003] Japanese Patent Application Laid-Open No. 2020-115053

[0004] Air conditioners operate at maximum output only for a very short period of the year. The rest of the time, they operate at low output. Even when operating at such low output, conventional air conditioners use fans and coils that consume a lot of energy, which limits the extent of energy savings. For example, even if an air conditioner could be operated at 30% of its maximum output, the problem remains that the air conditioner would be operating at excessive output because the maximum output is set too high.

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide an air conditioning system or the like that can respond to peak load times and can operate in an energy-saving manner outside of peak times.

[0006] To achieve the above object, an air conditioning system according to one aspect of the present invention includes at least two units selected from the following: a latent heat unit having a latent heat coil and a latent heat blower that sends air whose temperature has been adjusted by the latent heat coil to an air-conditioned space; a sensible heat unit having a sensible heat coil and a sensible heat blower that sends air whose temperature has been adjusted by the sensible heat coil to the air-conditioned space; and a blower unit having a blower that sends air to the air-conditioned space. With this configuration, for example, during peak load times, all of the units included in the air conditioning system can be operated, and during non-peak load times, one or more units can be turned off, thereby enabling energy-saving air conditioning.

[0007] Furthermore, the air conditioning device according to one aspect of the present invention may include a latent heat unit, a sensible heat unit, and an air blowing unit. With this configuration, humidity adjustment, temperature adjustment, and air blowing can be performed by operating each unit.

[0008] In addition, in an air conditioning device according to one aspect of the present invention, the latent heat unit may further have a return air blower that exhausts the return air from the air-conditioned space and / or blows it to the latent heat blower, the latent heat coil may adjust the temperature of at least one of the outside air and the return air blown by the return air blower of the latent heat unit, the sensible heat unit may further have a return air blower that exhausts the return air from the air-conditioned space and / or blows it to the sensible heat blower, the sensible heat coil may adjust the temperature of at least one of the outside air and the return air blown by the return air blower of the sensible heat unit, the blower unit may further have a return air blower that exhausts the return air from the air-conditioned space and / or blows it to the blower blower, and the blower blows at least one of the outside air and the return air blown by the return air blower of the blower unit. With this configuration, for example, it becomes possible to dehumidify, adjust the temperature, and blow air on mixed air obtained by mixing outside air and return air.

[0009] The air conditioning device according to one aspect of the present invention may further include a control unit that operates one or more of the latent heat unit, the sensible heat unit, and the air blower unit. With this configuration, for example, the control unit can prevent one or more of the units from operating, thereby enabling energy-saving air conditioning.

[0010] In an air conditioning system according to one aspect of the present invention, when the controller operates at least the latent heat unit and the sensible heat unit, the latent heat coil is supplied with chilled water from a heat source device having a refrigerator, the sensible heat coil is supplied with chilled water obtained by mixing the chilled water discharged from the latent heat coil with the chilled water from the heat source device, and the controller may control the mixing ratio of the chilled water discharged from the latent heat coil and the chilled water from the heat source device so that the chilled water supplied to the sensible heat coil has a desired temperature. With this configuration, the chilled water that has passed through the latent heat coil can be reused in the sensible heat coil, thereby promoting energy savings.

[0011] In addition, an air conditioning system according to one aspect of the present invention may further include an acquisition unit that acquires the temperature and humidity of the outside air, the temperature and humidity of the return air, the temperature and humidity of the air-conditioned space, the occupancy density in the air-conditioned space, and the carbon dioxide concentration in the air-conditioned space, and the control unit may operate one or more of the latent heat unit, the sensible heat unit, and the air blower unit based on the results acquired by the acquisition unit and the target temperature and target humidity of the air-conditioned space. With this configuration, one or more units can be operated based on the outside air temperature, etc.

[0012] In an air conditioning system according to one aspect of the present invention, the control unit may determine the volume of supply air to be supplied to the air-conditioned space based on the occupancy density in the air-conditioned space, determine the proportion of outside air in the supply air based on the carbon dioxide concentration in the air-conditioned space, determine whether to operate the latent heat unit based on the proportion of outside air, the temperature and humidity of the outside air, the temperature and humidity of the return air, the temperature and humidity of the air-conditioned space, and the target temperature and humidity of the air-conditioned space, determine whether to operate the sensible heat unit based on the proportion of outside air, the temperature of the outside air, the temperature of the return air, the temperature of the air-conditioned space, and the target temperature of the air-conditioned space, determine whether to operate the blower unit based on the volume of supply air, and control the latent heat unit, the sensible heat unit, and the blower unit according to the determination results. This configuration allows optimal control based on the obtained results, thereby achieving energy-saving air conditioning without sacrificing comfort in the air-conditioned space.

[0013] In the air conditioner according to one aspect of the present invention, when the control unit operates the latent heat unit and the sensible heat unit, the control unit may control the latent heat unit to adjust the temperature and humidity of the outside air or the return air, whichever has a higher absolute humidity. With this configuration, efficient dehumidification can be achieved.

[0014] Furthermore, a method for controlling an air conditioner according to one aspect of the present invention includes a latent heat unit having a latent heat coil, a latent heat blower that sends air whose temperature has been adjusted by the latent heat coil to an air-conditioned space, and a return air blower that performs at least one of exhaust and blowing of return air from the air-conditioned space to the latent heat blower; a sensible heat unit having a sensible heat coil, a sensible heat blower that sends air whose temperature has been adjusted by the sensible heat coil to the air-conditioned space, and a return air blower that performs at least one of exhaust and blowing of return air from the air-conditioned space to the sensible heat blower; and a blower that sends air to the air-conditioned space, and a blower that sends return air from the air-conditioned space to the exhaust and blowing of return air from the air-conditioned space to the blower. and a blower unit having a return air blower that performs at least one of the above, wherein the latent heat coil adjusts the temperature of at least one of the outside air and the return air blown by the return air blower of the latent heat unit, the sensible heat coil adjusts the temperature of at least one of the outside air and the return air blown by the return air blower of the sensible heat unit, and the blower blows at least one of the outside air and the return air blown by the return air blower of the blower unit, and the method includes the steps of operating one or more units from the latent heat unit, the sensible heat unit, and the blower unit.

[0015] According to an air conditioning device or the like according to one aspect of the present invention, for example, during peak load times, it is possible to respond by operating all units equipped in the air conditioning device, and during non-peak times, it is possible to perform energy-saving air conditioning by not operating one or more units.

[0016] Schematic diagram showing the configuration of an air conditioner according to an embodiment of the present invention; Block diagram showing the configuration related to control of the air conditioner according to the embodiment; Figure showing a piping system in the air conditioner according to the embodiment; Flowchart showing the operation of the air conditioner according to the embodiment; Figure showing another example of a piping system in the air conditioner according to the embodiment;

[0017] An air conditioner and a method for controlling an air conditioner according to the present invention will be described below using embodiments. In the following embodiments, components and steps with the same reference numerals are the same or equivalent, and repeated description may be omitted. The air conditioner according to this embodiment includes a latent heat unit that performs latent heat processing, a sensible heat unit that performs sensible heat processing, and an air blower unit that blows air, and operates one or more units depending on acquired results such as temperature.

[0018] FIG. 1 is a schematic diagram showing the configuration of an air conditioner 1 according to this embodiment, FIG. 2 is a block diagram showing the configuration related to the control of the air conditioner 1, and FIG. 3 is a diagram showing a piping system for supplying cold water to the latent heat coil 11 and the sensible heat coil 21.

[0019] The air conditioner 1 conditions the air in the air-conditioned space 3 and includes a latent heat unit 10 for dehumidifying, a sensible heat unit 20 for adjusting the temperature of the air, a blower unit 30 for blowing air, an acquisition unit 41 for acquiring information such as the temperature and humidity of the air-conditioned space 3, and a control unit 42 for controlling the latent heat unit 10, the sensible heat unit 20, and the blower unit 30 based on the results acquired by the acquisition unit 41. The air-conditioned space 3 is not particularly limited, and may be, for example, an office, a commercial facility, a store, a station, an airport, or an underground mall. The air-conditioned space 3 may also be, for example, a space where people come and go. Note that this embodiment will mainly describe a case where the air-conditioned space 3 is cooled.

[0020] The latent heat unit 10 is a unit that performs latent heat processing to adjust the humidity of the air, and has a latent heat coil 11, a latent heat blower 12, and a return air blower 13, and may have dampers 14 to 16 as necessary. The damper 14 adjusts the volume of air exhausted (EA) by the return air blower 13, the damper 15 adjusts the volume of outside air (OA) taken in by the latent heat blower 12, and the damper 16 may adjust the volume of return air (RA) blown from the return air blower 13 to the latent heat blower 12.

[0021] The latent heat coil 11 is a heat exchanger for adjusting the temperature and humidity of the air. To adjust the humidity, i.e., to perform dehumidification, the latent heat coil 11 may be supplied with cold water at a temperature equal to or lower than the dew point temperature of the air passing through the latent heat coil 11. As an example, cold water at 8°C may be supplied to the latent heat coil 11.

[0022] The latent heat blower 12 sends air whose temperature has been adjusted by the latent heat coil 11 to the air-conditioned space 3. Since the temperature and humidity are adjusted in the latent heat coil 11, the air whose temperature has been adjusted by the latent heat coil 11 is, strictly speaking, air whose temperature has been adjusted by the latent heat coil 11. The latent heat blower 12 may blow at least one of outside air and return air. The ratio of outside air to return air may be changed by, for example, adjusting the airflow rates of the dampers 15 and 16.

[0023] The return air blower 13 exhausts the return air from the air-conditioned space 3 and / or sends it to the latent heat blower 12. The ratio of exhaust air to air sent to the latent heat blower 12 may be changed, for example, by adjusting the air volume of the dampers 14 and 16. The return air sent to the latent heat blower 12 by the return air blower 13 is subject to temperature adjustment by the latent heat coil 11. Therefore, the latent heat coil 11 adjusts the temperature of at least one of the outside air and the return air sent by the return air blower 13.

[0024] Sensible heat unit 20 is a unit that performs sensible heat processing to adjust the temperature of the air, and has sensible heat coil 21, sensible heat blower 22, and return air blower 23, and may have dampers 24 to 26 as necessary. Damper 24 adjusts the volume of air exhausted by return air blower 23, damper 25 adjusts the volume of outside air taken in by sensible heat blower 22, and damper 26 may adjust the volume of return air blown from return air blower 23 to sensible heat blower 22.

[0025] The sensible heat coil 21 is a heat exchanger for adjusting the temperature of the air. Since no dehumidification is performed, the sensible heat coil 21 may be supplied with cold water at a temperature higher than the dew point temperature of the air passing through the sensible heat coil 21. In other words, the temperature of the cold water supplied to the sensible heat coil 21 may be higher than the temperature of the cold water supplied to the latent heat coil 11. As an example, cold water at 13°C may be supplied to the sensible heat coil 21.

[0026] The latent heat coil 11 and the sensible heat coil 21 may have the same configuration except for the temperature of the cold water supplied, or the latent heat coil 11 may be able to hold more cold water than the sensible heat coil 21. In this case, for example, the number of rows of the latent heat coil 11 may be greater than the number of rows of the sensible heat coil 21.

[0027] The sensible heat blower 22 sends air whose temperature has been adjusted by the sensible heat coil 21 to the air-conditioned space 3. The sensible heat blower 22 may blow at least one of outside air and return air. The ratio of outside air to return air may be changed by adjusting the airflow rates of the dampers 25 and 26, for example.

[0028] The return air blower 23 exhausts the return air from the air-conditioned space 3 and / or sends it to the sensible heat blower 22. The ratio of exhaust air to air sent to the sensible heat blower 22 may be changed, for example, by adjusting the air volume of the dampers 24, 26. The return air sent to the sensible heat blower 22 by the return air blower 23 is subject to temperature adjustment by the sensible heat coil 21. Therefore, the sensible heat coil 21 adjusts the temperature of at least one of the outside air and the return air blown by the return air blower 23 of the sensible heat unit 20.

[0029] The air blowing unit 30 is a unit that performs air blowing processing, and has an air blower 32 and a return air blower 33, and may have dampers 34 to 36 as necessary. The damper 34 adjusts the volume of air exhausted by the return air blower 33, the damper 35 adjusts the volume of outside air taken in by the air blower 32, and the damper 36 may adjust the volume of return air blown from the return air blower 33 to the air blower 32.

[0030] The blower 32 sends air to the air-conditioned space 3. The air blown by the blower 32 is air whose temperature and humidity have not been adjusted. The blower 32 may blow at least one of outside air and return air. The ratio of outside air to return air may be changed by adjusting the airflow rates of the dampers 35 and 36, for example.

[0031] The return air blower 33 exhausts the return air from the air-conditioned space 3 and / or sends it to the blower blower 32. Therefore, the blower blower 32 blows at least one of the outside air and the return air blown by the return air blower 33 of the blower unit 30. The ratio of the exhaust air and the air sent to the blower blower 32 may be changed by adjusting the air volume of the dampers 34, 36, for example.

[0032] The capacity of the blowers and coils of each unit may be determined so that the total capacity of the blowers and coils of all units in the air conditioner 1 according to this embodiment is approximately the same as the capacity of the blowers and coils of a conventional air conditioner. In this way, for example, by operating all units, it is possible to perform air conditioning at the same level as a conventional air conditioner, and by operating fewer units, it is possible to perform air conditioning with less energy than a conventional air conditioner. As an example, the maximum airflow of the blowers of each unit may be one-third of the maximum airflow of the blowers of a conventional air conditioner.

[0033] Furthermore, the volume of supply air supplied to the air-conditioned space 3 may be adjusted, for example, by a fan in each unit, or by a variable air volume device (VAV) provided in a duct through which the supply air passes. When adjusting the volume of air by a fan, a fan capable of adjusting the volume of air, such as an inverter-controlled fan or a fan using a DC motor, may be used in each unit.

[0034] The dampers 14-16, 24-26, and 34-36 may be, for example, motor dampers, and the air volume may be adjustable by the control unit 42. For example, in the latent heat unit 10, the proportion of outside air in the air supplied from the latent heat unit 10 to the air-conditioned space 3 can be changed by adjusting the air volume of the dampers 15 and 16. Also, in the latent heat unit 10, the proportion of exhaust air in the return air to the latent heat unit 10 can be changed by adjusting the air volume of the dampers 14 and 16. The same applies to the sensible heat unit 20 and the blower unit 30. Furthermore, to prevent the air sent from each unit to the air-conditioned space 3 from flowing back into other units, the supply air output from each unit may be supplied to the air-conditioned space 3 via a backflow prevention damper provided in each duct.

[0035] The acquisition unit 41 acquires the temperature and humidity of the outside air, the temperature and humidity of the return air, the temperature and humidity of the air-conditioned space 3, the occupancy density in the air-conditioned space 3, and the carbon dioxide concentration in the air-conditioned space 3. The temperature may be the so-called dry-bulb temperature. The humidity may be, for example, relative humidity or absolute humidity. Furthermore, information other than humidity may be acquired as long as it results in the acquisition of humidity. For example, humidity can be acquired using the dry-bulb temperature and wet-bulb temperature of the air. Therefore, acquiring the temperature and humidity of the air may mean, for example, acquiring the dry-bulb temperature and relative humidity of the air, or acquiring the dry-bulb temperature and wet-bulb temperature of the air. In this embodiment, a case where the humidity acquired by the acquisition unit 41 is relative humidity will be mainly described.

[0036] The temperature and humidity of the outside air may be acquired, for example, by a temperature sensor that measures the temperature of the outside air and a humidity sensor that measures the humidity of the outside air. The temperature and humidity of the outside air may be measured, for example, near the outside air intake. The temperature and humidity of the return air may be acquired, for example, by a temperature sensor that measures the temperature of the return air and a humidity sensor that measures the humidity of the return air. The temperature and humidity of the return air are preferably measured in the latent heat unit 10, the sensible heat unit 20, and the blower unit 30, or near each unit. It is also preferable to measure the temperature and humidity of the return air of an operating unit, i.e., the unit that is blowing air. When all units are not operating, the temperature and humidity of the air-conditioned space 3 may be used as the temperature and humidity of the return air. The temperature and humidity of the air-conditioned space 3 may be acquired, for example, by a temperature sensor and a humidity sensor disposed in the air-conditioned space 3. When the air-conditioned space 3 is large, measurements may be performed at multiple locations, and representative values ​​may be used as the temperature and humidity of the air-conditioned space 3. The representative values ​​may be, for example, averages or medians. Furthermore, as described above, for example, the wet bulb temperature may be acquired instead of the humidity.

[0037] For example, the occupancy density in the air-conditioned space 3 may be obtained by acquiring the number of people present in the air-conditioned space 3 and dividing that number by the area of ​​the air-conditioned space 3. The calculation of the occupancy density may be performed, for example, by the acquisition unit 41 or another device. In the latter case, the acquisition unit 41 may accept the calculated occupancy density. The number of people present in the air-conditioned space 3 may be acquired, for example, using images captured by a camera. Acquiring the number of people using the captured images may be performed, for example, by detecting people in the captured images and counting the detected people. If the air-conditioned space 3 is large, the number of people present in the air-conditioned space 3 may be acquired using images captured by two or more cameras. Alternatively, the number of people present in the air-conditioned space 3 may be acquired using other methods. For example, the acquisition unit 41 may acquire the number of people present in the air-conditioned space 3 using a media access control (MAC) address included in a wireless signal transmitted from a mobile device such as a smartphone. In addition, the acquisition unit 41 may acquire the number of people present in the air-conditioned space 3, for example, by acquiring the number of people who have entered the air-conditioned space 3 and the number of people who have left the air-conditioned space 3 at the entrance and exit of the air-conditioned space 3.

[0038] The carbon dioxide concentration in the air-conditioned space 3 may be measured, for example, by a CO2 sensor placed in the air-conditioned space 3. If the air-conditioned space 3 is large, measurements may be taken at multiple locations and a representative value thereof may be used as the carbon dioxide concentration in the air-conditioned space 3. The representative value may be, for example, an average value or a median value.

[0039] The acquisition unit 41 may include sensors such as a temperature sensor and a humidity sensor, or may receive information from sensors such as a temperature sensor and a humidity sensor via a wired or wireless connection.

[0040] The control unit 42 operates one or more of the latent heat unit 10, the sensible heat unit 20, and the blower unit 30. The control unit 42 may operate one or more of the latent heat unit 10, the sensible heat unit 20, and the blower unit 30, for example, based on the results acquired by the acquisition unit 41 and the target temperature and target humidity of the air-conditioned space 3. Details of this control will be described later. Note that if the information acquired by the acquisition unit 41 satisfies a predetermined condition, such as the temperature and humidity of the air-conditioned space 3 being close to the target temperature and target humidity, the control unit 42 may not operate any of the units. The control unit 42 may also control, for example, the heat source device 5. For example, when the latent heat unit 10 is not operated and the sensible heat unit 20 is operated, the control unit 42 may control the heat source device 5 to increase the temperature of the supplied chilled water. Alternatively, when the latent heat unit 10 and the sensible heat unit 20 are not operated, the control unit 42 may control the heat source device 5 to stop the supply of chilled water.

[0041] The control unit 42 may control the temperature of the chilled water supplied to the sensible heat coil 21. This control will be described with reference to FIG. 3 . As shown in FIG. 3 , the heat source equipment 5 may generate chilled water using cooling water supplied from a cooling tower 5 and return the used, high-temperature chilled water to the cooling tower 5. The chilled water generated by the heat source equipment 5 may be supplied to the latent heat coil 11 and the sensible heat coil 21 via a pipe 61. The flow rate of the chilled water supplied from the heat source equipment 5 to the latent heat coil 11 may be adjusted by a flow control valve 51, and the flow rate of the chilled water supplied from the heat source equipment 5 to the sensible heat coil 21 may be adjusted by a flow control valve 54. The chilled water discharged from the latent heat coil 11 may be supplied to the sensible heat coil 21 via a pipe 63. The flow rate of the chilled water supplied from the latent heat coil 11 to the sensible heat coil 21 via the pipe 63 may be adjusted by a flow control valve 53. Furthermore, the chilled water discharged from the latent heat coil 11 and the sensible heat coil 21 may be returned to the heat source equipment 5 via piping 62. Of the chilled water discharged from the latent heat coil 11, the flow rate of chilled water returning to the heat source equipment 5 may be adjusted by a flow control valve 52. Furthermore, the temperature of the chilled water supplied to the sensible heat coil 21 may be measured by a temperature sensor 55. The temperature measurement by this temperature sensor 55 may be performed, for example, between the connection point of the pipes 61, 63 and the sensible heat coil 21. Although not shown in FIG. 3 , the pipe 61 may have a pump for sending chilled water to the latent heat coil 11, etc.

[0042] The control unit 42 may control the mixing ratio of the cold water discharged from the latent heat coil 11 and the cold water from the heat source equipment 5 so that the cold water supplied to the sensible heat coil 21 has a desired temperature when at least the latent heat unit 10 and the sensible heat unit 20 are operated. More specifically, when both the latent heat unit 10 and the sensible heat unit 20 are operated, the control unit 42 may supply the cold water from the heat source equipment 5 to the latent heat coil 11 by opening the flow rate adjustment valve 51. The control unit 42 may also open the flow rate adjustment valves 53 and 54 so that the cold water obtained by mixing the cold water discharged from the latent heat coil 11 and the cold water from the heat source equipment 5 is supplied to the sensible heat coil 21. Note that when the water pressure in the pipe 61 is higher than the water pressure in the pipe 63, the control unit 42 may only slightly open the flow rate adjustment valve 54. The control unit 42 may also acquire the temperature of the chilled water supplied to the sensible heat coil 21 measured by the temperature sensor 55 and adjust the flow rate control valves 53, 54 so that the temperature becomes a target temperature. For example, to lower the temperature of the chilled water supplied to the sensible heat coil 21, the control unit 42 may adjust the flow rate control valves 53, 54 so that more chilled water from the heat source equipment 5 is supplied to the sensible heat coil 21. To raise the temperature of the chilled water supplied to the sensible heat coil 21, the control unit 42 may adjust the flow rate control valve 52 so that more chilled water from the latent heat coil 11 is supplied to the sensible heat coil 21. The control unit 42 may also adjust the flow rate control valve 52 according to the flow rate of the chilled water passing through the flow rate control valve 53, so that the chilled water is appropriately discharged from the latent heat coil 11. As an example, when the chilled water supplied from the heat source equipment 5 is 8°C, the control unit 42 may adjust the flow rate control valves 53, 54 so that chilled water at 13°C is supplied to the sensible heat coil 21. In this way, the control unit 42 can provide chilled water at a target temperature to the sensible heat coil 21 by using chilled water discharged from the latent heat coil 11 and chilled water from the heat source equipment 5. Furthermore, by reusing the chilled water discharged from the latent heat coil 11, the energy saving effect can be enhanced.

[0043] When the latent heat unit 10 is not operated, the control unit 42 may close the flow rate adjustment valve 51 so that cold water is not supplied to the latent heat coil 11. In this case, only cold water from the heat source equipment 5 may be supplied to the sensible heat coil 21. Since the cold water supplied to the sensible heat coil 21 may have a higher temperature than the cold water supplied to the latent heat coil 11, when the latent heat unit 10 is not operated, the control unit 42 may control the heat source equipment 5 to increase the temperature of the cold water supplied by the heat source equipment 5.

[0044] Furthermore, when sensible heat unit 20 is not operated, control unit 42 may close flow rate adjustment valves 53 and 54 to prevent cold water from being supplied to sensible heat coil 21. In this case, control unit 42 may fully open flow rate adjustment valve 52.

[0045] Next, the control of the latent heat unit 10, the sensible heat unit 20, and the blower unit 30 by the control unit 42 using the results acquired by the acquisition unit 41 will be described. First, the control unit 42 may determine the air volume of the supply air supplied to the air-conditioned space 3 based on the occupancy density in the air-conditioned space 3 acquired by the acquisition unit 41. For example, the air volume may be determined so that the greater the occupancy density in the air-conditioned space 3, the greater the air volume of the supply air. The relationship between the occupancy density and the air volume of the supply air is shown, for example, by a table or a function, and the control unit 42 may use these to determine the air volume according to the occupancy density. As an example, when the occupancy density in the air-conditioned space 3 is 0.4 people / m, ２ exceeding the predetermined air volume, the control unit 42 may determine the air volume of the supply air to be the maximum air volume, that is, the maximum air volume that can be achieved by the three units. Note that, for example, if the air volume of the supply air supplied to the air-conditioned space 3 is adjusted by a variable air volume device, the control unit 42 may control the variable air volume device in accordance with the determined air volume. Also, for example, if the air volume of the supply air supplied to the air-conditioned space 3 is adjusted by a fan in each unit, the control unit 42 may control each fan in the unit to be operated so as to achieve the determined air volume.

[0046] Note that when determining the volume of supply air, the control unit 42 may use the temperature of the air-conditioned space 3 acquired by the acquisition unit 41 and the target temperature of the air-conditioned space 3. For example, when the absolute value of the difference between the temperature of the air-conditioned space 3 and the target temperature is smaller than a first threshold and the occupancy density in the air-conditioned space 3 is smaller than a second threshold, the control unit 42 may determine the volume of supply air supplied to the air-conditioned space 3 to be 0. The first threshold is preferably a small positive real number that allows for determining that the two temperatures are substantially the same. For example, the first threshold may be 1°C or 2°C. The second threshold is preferably a small positive real number that allows for determining that there are substantially few people in the air-conditioned space 3. For example, the second threshold is 0.1 people / m ２ or 0.05 people / m ２ etc. When the volume of supply air to the air-conditioned space 3 becomes zero, the control unit 42 may, for example, stop the operation of all units. In this case, the air blowing by the air conditioner 1 stops, and the volume of return air also becomes zero. Therefore, it becomes impossible to measure the temperature, humidity, and carbon dioxide concentration of the air-conditioned space 3 using the return air. For this reason, when there is a possibility that the volume of supply air to the air-conditioned space 3 will become zero, it is preferable to measure the temperature, humidity, and carbon dioxide concentration of the air-conditioned space 3 directly in the air-conditioned space 3.

[0047] The control unit 42 may determine the proportion of outside air contained in the supply air based on the carbon dioxide concentration in the air-conditioned space 3 acquired by the acquisition unit 41. For example, the proportion of outside air may be determined so that the higher the carbon dioxide concentration in the air-conditioned space 3, the higher the proportion of outside air contained in the supply air supplied to the air-conditioned space 3. The relationship between the carbon dioxide concentration and the proportion of outside air may be represented by, for example, a table or a function, and the control unit 42 may use these to determine the proportion of outside air according to the carbon dioxide concentration.

[0048] The control unit 42 may determine whether to operate the latent heat unit 10 based on the determined proportion of outside air, the temperature and humidity of the outside air, the temperature and humidity of the return air, and the temperature and humidity of the air-conditioned space 3 acquired by the acquisition unit 41, and the target temperature and target humidity of the air-conditioned space 3. The target temperature and target humidity of the air-conditioned space 3 are stored in a recording medium (not shown), and the control unit 42 may read and use them. The target temperature and target humidity may be set, for example, by a user or by a central control device.

[0049] The control unit 42 may, for example, use information such as the determined ratio of outside air and the acquired temperature and humidity of the outside air to determine whether dehumidification is necessary for the mixed air of outside air and return air mixed in the determined ratio, and may decide to operate the latent heat unit 10 if dehumidification is necessary, or may decide not to operate the latent heat unit 10 if dehumidification is not necessary.

[0050] Whether dehumidification of the mixed air is necessary may be determined, for example, as follows. The control unit 42 can obtain the current absolute humidity of the mixed air of the outside air and the return air mixed at the determined ratio by using the determined ratio of outside air, the acquired temperature and humidity of the outside air, and the acquired temperature and humidity of the return air. The control unit 42 can also obtain the current absolute humidity of the air-conditioned space 3 by using the acquired temperature and humidity of the air-conditioned space 3. The control unit 42 can also obtain the target absolute humidity of the air-conditioned space 3 by using the target temperature and target humidity of the air-conditioned space 3. The absolute humidity may be obtained using a psychrometric chart, for example.

[0051] Furthermore, the control unit 42 may determine the absolute humidity of the supply air supplied to the air-conditioned space 3 based on, for example, the current absolute humidity of the air-conditioned space 3 and a target absolute humidity of the air-conditioned space 3. For example, if the current absolute humidity of the air-conditioned space 3 is equal to or lower than the target absolute humidity of the air-conditioned space 3, the absolute humidity of the supply air may be determined to be the target absolute humidity of the air-conditioned space 3. If the current absolute humidity of the air-conditioned space 3 is higher than the target absolute humidity of the air-conditioned space 3, the absolute humidity of the supply air may be determined to be an absolute humidity lower than the target absolute humidity of the air-conditioned space 3. Note that if the current absolute humidity of the air-conditioned space 3 is higher than the target absolute humidity of the air-conditioned space 3, the greater the difference between the two absolute humidity values, the lower the absolute humidity of the supply air may be determined to be. The control unit 42 may then determine that dehumidification is necessary, for example, if dehumidification is necessary to change the absolute humidity of the current mixed air to the absolute humidity of the supply air.

[0052] More specifically, the control unit 42 may determine that dehumidification is necessary if the result of subtracting the absolute humidity of the supply air from the current absolute humidity of the mixed air is greater than a third threshold, and may determine that dehumidification is not necessary if the result of the subtraction is less than the third threshold. Note that, for example, if the result of the subtraction is equal to the third threshold, the control unit 42 may determine that dehumidification is necessary, or may not. The third threshold is a real number greater than or equal to 0, and is preferably a small value that allows the control unit 42 to determine that the absolute humidity of the supply air and the current absolute humidity of the mixed air are substantially equal when the result of subtracting the absolute humidity of the supply air from the current absolute humidity of the mixed air is greater than or equal to 0 and less than the third threshold. For example, the third threshold may be 0.0001 kg / kg (DA).

[0053] The control unit 42 may determine whether dehumidification of the mixed air is necessary using a method different from that described above. For example, the control unit 42 may determine that dehumidification is necessary when the current absolute humidity of the air-conditioned space 3 is higher than the target humidity and dehumidification is necessary to bring the current absolute humidity of the mixed air to the target absolute humidity, and may determine that dehumidification is not necessary when this is not the case.

[0054] The control unit 42 may decide whether to operate the sensible heat unit 20 based on the determined proportion of outside air, the temperature of the outside air, the temperature of the return air, and the temperature of the air-conditioned space 3 acquired by the acquisition unit 41, and the target temperature of the air-conditioned space 3.

[0055] The control unit 42 may, for example, use information such as the determined ratio of outside air and the acquired temperature of outside air to determine whether the mixed air of outside air and return air mixed in the determined ratio requires temperature adjustment, more specifically, cooling, and may decide to operate the sensible heat unit 20 if temperature adjustment is required, or may decide not to operate the sensible heat unit 20 if temperature adjustment is not required.

[0056] Whether or not the temperature of the mixed air needs to be adjusted may be determined, for example, as follows. The control unit 42 can obtain the current temperature of the mixed air of outside air and return air mixed at the determined ratio by using the determined ratio of outside air, the acquired temperature of outside air, and the acquired temperature of return air. The control unit 42 may also determine the temperature of the supply air to be supplied to the air-conditioned space 3, for example, based on the acquired temperature of the air-conditioned space 3 and a target temperature of the air-conditioned space 3. For example, if the acquired temperature of the air-conditioned space 3 is equal to or lower than the target temperature of the air-conditioned space 3, the temperature of the supply air may be determined to be the target temperature of the air-conditioned space 3. If the acquired temperature of the air-conditioned space 3 is higher than the target temperature of the air-conditioned space 3, the temperature of the supply air may be determined to be lower than the target temperature of the air-conditioned space 3. Note that if the acquired temperature of the air-conditioned space 3 is higher than the target temperature of the air-conditioned space 3, the greater the difference between the two temperatures, the lower the temperature of the supply air may be determined to be. Then, the control unit 42 may determine that temperature adjustment is necessary, for example, when temperature adjustment is necessary to change the temperature of the mixed air from the current temperature to the temperature of the supply air.

[0057] More specifically, the control unit 42 may determine that temperature adjustment is necessary if the result of subtracting the supply air temperature from the current mixed air temperature is greater than a fourth threshold, and may determine that temperature adjustment is not necessary if the result of the subtraction is less than the fourth threshold. For example, if the result of the subtraction is equal to the fourth threshold, the control unit 42 may determine that temperature adjustment is necessary, or may not. The fourth threshold is a real number greater than or equal to 0, and is preferably a small value that allows determination that the two temperatures are substantially equal when the result of subtracting the supply air temperature from the current mixed air temperature is greater than or equal to 0 and less than the fourth threshold. The control unit 42 may change the threshold depending on, for example, whether or not the latent heat unit 10 is operated. For example, when the latent heat unit 10 is not operated, the control unit 42 may make a determination using the fourth threshold as described above, and when the latent heat unit 10 is operated, the control unit 42 may make a determination using a fifth threshold instead of the fourth threshold. The fifth threshold may be a real number greater than the fourth threshold. The fifth threshold value is preferably a value that allows the operated latent heat unit 10 to adjust the current mixed air temperature to the determined supply air temperature when the result of subtracting the supply air temperature from the current mixed air temperature is greater than the fourth threshold value but less than the fifth threshold value. For example, the fourth threshold value may be 1°C or 2°C, and the fifth threshold value may be 4°C or 5°C.

[0058] The control unit 42 may determine whether the temperature of the mixed air needs to be adjusted using a method different from that described above. For example, the control unit 42 may determine that temperature adjustment is necessary when the current temperature of the air-conditioned space 3 is higher than the target temperature and temperature adjustment is necessary to bring the current temperature of the mixed air up to the target temperature, and may determine that temperature adjustment is not necessary when this is not the case.

[0059] The control unit 42 may determine whether to operate the blower unit 30 based on the determined air volume of the supply air. For example, when at least one of the latent heat unit 10 and the sensible heat unit 20 is operated, the control unit 42 may determine not to operate the blower unit 30 if the determined air volume of the supply air can be covered by the unit to be operated, and may determine to operate the blower unit 30 if this is not the case. Note that the control unit 42 may determine to operate the blower unit 30 if, for example, neither the latent heat unit 10 nor the sensible heat unit 20 is operated and the determined air volume of the supply air is not zero.

[0060] The control unit 42 may also control the latent heat unit 10, the sensible heat unit 20, and the blower unit 30 according to the determination result. That is, the control unit 42 may operate the latent heat unit 10, the sensible heat unit 20, and the blower unit 30 that it has determined to operate, and may not operate the units that it has determined not to operate. For example, when the latent heat unit 10 is set to be operated, the control unit 42 may operate the latent heat blower 12 and the return air blower 13, and adjust the flow control valves 51 and 52 so that cold water is supplied to the latent heat coil 11. For example, when the sensible heat unit 20 is set to be operated, the control unit 42 may operate the sensible heat blower 22 and the return air blower 23, and adjust the flow control valves 52 to 54 according to the temperature measured by the temperature sensor 55 so that cold water at a desired temperature is supplied to the sensible heat coil 21. Furthermore, for example, when the air blower unit 30 becomes the operation target, the control unit 42 may operate the air blower 32 and the return air blower 33. Furthermore, the control unit 42 may control, for example, the dampers 14 to 16, 24 to 26, and 34 to 36 so that a desired ratio of outside air and return air is blown in each unit.

[0061] Furthermore, when operating the latent heat unit 10 and the sensible heat unit 20, the control unit 42 may control the latent heat unit 10 to adjust the temperature and humidity of the outside air or the return air, whichever has a higher absolute humidity. That is, the outside air and the return air may be allocated to each unit so that the air with a higher absolute humidity is preferentially processed in the latent heat unit 10. In summer, the absolute humidity of the outside air is usually higher than the absolute humidity of the return air. In this case, the control unit 42 may control the dampers of the latent heat unit 10 and the sensible heat unit 20 so that the temperature of the outside air is mainly adjusted by the latent heat unit 10.

[0062] More specifically, the volume of outside air can be determined based on the determined volume and the proportion of outside air. If all of the volume of outside air can be allocated to the latent heat unit 10, i.e., if all of the volume of outside air can be blown by the latent heat unit 10, the control unit 42 may control the dampers 14-16 and 24-26 so that the outside air is introduced only into the latent heat unit 10. In this case, the latent heat unit 10 may adjust the temperature of only the outside air, or may adjust the temperature of a mixture of outside air and return air. If the latent heat unit 10 alone cannot blow all of the determined volume of outside air, the control unit 42 may allocate the volume of outside air to the latent heat unit 10 and the sensible heat unit 20, and may also allocate it to the blower unit 30. In other words, the control unit 42 may control the latent heat unit 10 so that only the outside air is adjusted in temperature, and control the remaining outside air to be blown by the sensible heat unit 20 and, if necessary, by the blower unit 30. Furthermore, the control unit 42 may control the air volume of the return air supplied from the latent heat unit 10 and the sensible heat unit 20 to the air-conditioned space 3 so as to achieve the determined ratio of outside air to return air, and may further control the air volume of the return air supplied from the blower unit 30 to the air-conditioned space 3, if necessary. These controls may be performed by adjusting the air volume of the damper provided in each unit.

[0063] Furthermore, when operating sensible heat unit 20 and blower unit 30, control unit 42 may control the sensible heat unit 20 to adjust the temperature of the higher-temperature outside air or return air. That is, outside air and return air may be allocated to each unit so that the higher-temperature air is preferentially blown out by sensible heat unit 20. In summer, the temperature of outside air is usually higher than the temperature of return air. In this case, control unit 42 may control the dampers of sensible heat unit 20 and blower unit 30 so that the temperature of outside air is mainly adjusted by sensible heat unit 20.

[0064] Next, the operation of the air conditioner 1 will be described using the flowchart in Figure 4. (Step S101) The control unit 42 determines whether or not to perform control for each unit. If control is to be performed, the process proceeds to step S102. If not, the process of step S101 is repeated until it is determined that control is to be performed. Note that the control unit 42 may, for example, periodically (e.g., every 30 minutes or every hour) determine that control is to be performed.

[0065] (Step S102) The acquisition unit 41 acquires information such as the temperature and humidity of the outside air. The acquired information may be stored in, for example, a recording medium (not shown).

[0066] (Step S103) The control unit 42 determines the volume of supply air to be supplied to the air-conditioned space 3 based on the acquired occupancy density in the air-conditioned space 3.

[0067] (Step S104) The control unit 42 determines the proportion of outside air contained in the supply air based on the acquired carbon dioxide concentration in the air-conditioned space 3.

[0068] (Step S105) The control unit 42 determines whether dehumidification is necessary based on the proportion of outside air, etc. If dehumidification is necessary, the process proceeds to step S106, and if not, the process proceeds to step S107.

[0069] (Step S106) The control unit 42 sets the latent heat unit 10 as the unit to be operated.

[0070] (Step S107) The control unit 42 determines whether temperature adjustment is necessary based on the proportion of outside air, etc. If temperature adjustment is necessary, the process proceeds to step S108, and if not, the process proceeds to step S109.

[0071] (Step S108) The control unit 42 sets the sensible heat unit 20 as the unit to be operated.

[0072] (Step S109) The control unit 42 determines whether additional air volume is required by comparing the air volume of the supply air supplied to the air-conditioned space 3 by the units that have been set as operation targets up to that point with the air volume determined in step S103. If additional air volume is required, the process proceeds to step S110; otherwise, the process proceeds to step S111. Note that the control unit 42 may determine that additional air volume is not required if the air volume determined in step S103 can be covered by the units that have been set as operation targets up to that point, and may determine that additional air volume is required if this is not the case.

[0073] (Step S110) The control unit 42 sets the air blowing unit 30 as the unit to be operated.

[0074] (Step S111) The control unit 42 controls each unit set as an operation target so that temperature-adjusted supply air is supplied to the air-conditioned space 3. Then, the process returns to step S101. Note that the control content in step S111 may be maintained until it is determined in step S101 that the next control should be performed. In other words, the same control may be continued until it is determined in step S101 that the next control should be performed.

[0075] The order of the steps in the flowchart of Fig. 4 is an example, and the order of the steps may be changed as long as the same results are obtained. In the flowchart of Fig. 4, the process ends when the power is turned off or an interrupt to end the process occurs.

[0076] Next, the operation of the air conditioner 1 according to this embodiment will be described using a specific example. When the time to perform control arrives, the control unit 42 instructs the acquisition unit 41 to acquire various information (step S101). Upon receiving this instruction, the acquisition unit 41 acquires various information, such as the temperature and humidity of the outside air, and passes this information to the control unit 42 (step S102). Upon receiving the information acquired by the acquisition unit 41, the control unit 42 first determines the air volume of the air to be supplied to the air-conditioned space 3 based on the acquired occupancy density in the air-conditioned space 3 (step S103). It is assumed that the determined air volume is A1. Furthermore, the control unit 42 determines the proportion of outside air contained in the air to be supplied to the air-conditioned space 3 based on the acquired carbon dioxide concentration in the air-conditioned space 3 (step S104). It is assumed that the determined proportion of outside air is A2.

[0077] The control unit 42 uses the ratio A2 of outside air, the acquired temperature and humidity of outside air, the acquired temperature and humidity of return air, and the acquired temperature and humidity of the air-conditioned space 3 to acquire the current absolute humidity of the mixed air of outside air and return air mixed at the ratio A2 of outside air, and the current absolute humidity of the air-conditioned space 3. The control unit 42 also uses the target temperature and target humidity of the air-conditioned space 3 to acquire the target absolute humidity of the air-conditioned space 3. The control unit 42 then determines whether dehumidification is necessary using the current absolute humidity of the mixed air, the current absolute humidity of the air-conditioned space 3, and the target absolute humidity of the air-conditioned space 3 (step S105). In this case, it is assumed that it has been determined that dehumidification is necessary. The control unit 42 then sets the latent heat unit 10 as the unit to be operated (step S106).

[0078] The control unit 42 also uses the ratio A2 of outside air, the acquired temperature of outside air, and the acquired temperature of return air to acquire the current temperature of the mixed air of outside air and return air mixed at ratio A2. The control unit 42 then determines whether temperature adjustment is necessary using the current temperature of the mixed air, the current temperature of the air-conditioned space 3, and the target temperature of the air-conditioned space 3 (step S107). In this case, it is assumed that it is determined that temperature adjustment is necessary. Then, the control unit 42 sets the sensible heat unit 20 as the unit to be operated (step S108).

[0079] The control unit 42 also determines whether the determined air volume A1 can be covered by the latent heat unit 10 and the sensible heat unit 20 that are set to be operated (step S109). In this case, it is assumed that the air volume A1 is smaller than the sum of the air volumes of the latent heat unit 10 and the sensible heat unit 20. In this case, the control unit 42 determines that additional air volume is not necessary, and does not set the blower unit 30 as a unit to be operated.

[0080] Thereafter, the control unit 42 controls the latent heat units 10 and sensible heat units 20 that have been set as operation targets (step S111). Specifically, the control unit 42 calculates the outdoor air volume B1 and the return air volume B2 using the determined air volume A1 and the determined outdoor air ratio A2. The control unit 42 also compares the current absolute humidity of the outdoor air with the current absolute humidity of the return air to identify the one with the higher absolute humidity. In this case, it is assumed that the current absolute humidity of the outdoor air is higher than the current absolute humidity of the return air. The control unit 42 then allocates the outdoor air and the return air so that the outdoor air is preferentially processed by the latent heat unit 10.

[0081] Specifically, if the air volume B1 of the outside air is equal to or less than the air volume of the latent heat unit 10 set to be operated, the control unit 42 allocates the air volume B1 of the outside air only to the latent heat unit 10. In this case, if the air volume B2 of the return air is equal to or less than the air volume of the sensible heat unit 20 set to be operated, the control unit 42 allocates the air volume B2 of the return air only to the sensible heat unit 20, and otherwise allocates the air volume B2 of the return air to the latent heat unit 10 and the sensible heat unit 20. When the air volume B2 of the return air is allocated to the latent heat unit 10 and the sensible heat unit 20, the allocation is performed so that only the return air is processed in the sensible heat unit 20.

[0082] If the air volume B1 of the outside air is not equal to or less than the air volume of the latent heat unit 10, the control unit 42 allocates the air volume B1 of the outside air to the latent heat unit 10 and the sensible heat unit 20. In this case, allocation is performed so that only the outside air is processed in the latent heat unit 10. Then, the air volume B2 of the return air is allocated only to the sensible heat unit 20.

[0083] After allocating the outside air and the return air in this manner, the control unit 42 controls the dampers 14-16 and 24-26 so that air is blown in accordance with the allocation. Specifically, by adjusting the dampers 14-16, the outside air and the return air are blown in proportions according to the allocation by the latent heat blower 12, and the temperature and humidity are adjusted by the latent heat coil 11 before being supplied to the air-conditioned space 3. Also, by adjusting the dampers 24-26, the outside air and the return air are blown in proportions according to the allocation by the sensible heat blower 22, and the temperature is adjusted by the sensible heat coil 21 before being supplied to the air-conditioned space 3. Furthermore, for example, if the blowers in each unit are capable of adjusting the air volume by inverter control or the like, the blowers in each unit set to operate may be controlled so as to achieve the desired air volume.

[0084] The control unit 42 also adjusts the flow rate control valve 51 so that the cold water from the heat source equipment 5 is supplied to the latent heat coil 11. The control unit 42 also adjusts the flow rate control valves 53 and 54 so that the temperature of the cold water acquired by the temperature sensor 55 becomes a predetermined temperature, and adjusts the flow rate control valve 52 according to the adjustment result so that water is appropriately drained from the latent heat coil 11. Note that the predetermined temperature may be, for example, a predetermined temperature, or may be determined based on the current temperature of the air-conditioned space 3 and the target temperature of the air-conditioned space 3. For example, the greater the difference between the two temperatures, the lower the temperature that may be determined.

[0085] If the air volumes of the latent heat unit 10 and the sensible heat unit 20 are not enough to cover the determined air volume A1, the blower unit 30 may also be set as an operation target (step S110). In this case, of the outside air and the return air, the air with a higher absolute humidity may be preferentially allocated to the latent heat unit 10, and next, of the outside air and the return air, the air with a higher temperature may be preferentially allocated to the sensible heat unit 20.

[0086] Furthermore, when it is determined that dehumidification is not necessary, the latent heat unit 10 is not set as an operation target, and only the sensible heat unit 20, only the blower unit 30, or both the sensible heat unit 20 and the blower unit 30 may operate. When the sensible heat unit 20 and the blower unit 30 operate, the air with a higher temperature, between the outside air and the return air, may be preferentially allocated to the sensible heat unit 20.

[0087] As described above, the air conditioner 1 according to this embodiment includes three units with different functions, thereby promoting energy conservation when performing air conditioning at low power. For example, if air conditioning can be performed using only sensible heat treatment, energy consumption can be reduced by not operating the latent heat unit 10 and the blower unit 30. Furthermore, if each unit has a blower that can adjust the air volume using inverter control or the like, it is possible to operate only the sensible heat unit 20 at 30% power. Therefore, the air conditioner 1 as a whole can be operated at, for example, 10% of its maximum power, enabling lower-power operation. Furthermore, operating all units can also accommodate air conditioning during peak loads. Furthermore, because the air conditioner is divided into multiple units, even if one unit fails, the other units can continue to operate, preventing a complete shutdown of the air conditioning system. Furthermore, because the air conditioner is divided into multiple units, installation work is easier than when installing an air conditioner consisting of a single large unit as in the past.

[0088] In this embodiment, as shown in Fig. 3, the case where chilled water discharged from the latent heat coil 11 is supplied to the sensible heat coil 21 has been described, but this is not necessarily the case. Chilled water from a heat source device may be supplied to each of the latent heat coil 11 and the sensible heat coil 21. In this case, for example, chilled water may be supplied to the latent heat coil 11 from a first heat source device, and chilled water may be supplied to the sensible heat coil 21 from a second heat source device different from the first heat source device. As an example, chilled water at 8°C may be supplied to the latent heat coil 11 from the first heat source device, and chilled water at 13°C may be supplied to the sensible heat coil 21 from the second heat source device.

[0089] Furthermore, when the latent heat coil 11 is not used and the sensible heat coil 21 is used, i.e., when the latent heat unit 10 is not operated by the control unit 42 and the sensible heat unit 20 is operated, cooling water may be supplied from the cooling tower 6 to the sensible heat coil 21 of the sensible heat unit 20. In this case, as shown in FIG. 5 , cooling water from the cooling tower 6 may be supplied to the pipe 61 via the pipe 71. Furthermore, cooling water discharged from the sensible heat coil 21 may be returned to the cooling tower 6 via the pipes 62 and 72. When cooling water generated by the cooling tower 6 is supplied to the sensible heat coil 21, valves 81 and 84 may be opened and valves 82, 83, 85, and 86 may be closed. Furthermore, valves 51 to 53 may be closed and valve 54 may be opened. Opening and closing of these valves may be performed by, for example, the control unit 42. In this case, the heat source equipment 5 may be stopped. In this way, operating the sensible heat unit 21 using the cooling water supplied from the cooling tower 6 can further promote energy savings. Note that when cold water from the heat source equipment 5 is supplied to the latent heat coil 11, etc., valves 81 and 84 may be closed and valves 82, 83, 85, and 86 may be opened, and the heat source equipment 5 may be operated. In this way, for example, when the sensible heat unit 20 is operated and the latent heat unit 10 is not operated, the control unit 42 may control the supply of cold water from the cooling tower 6 to the sensible heat coil 21, and when at least the latent heat unit 10 is operated, the control unit 42 may control the supply of cold water from the cooling tower 6 to the heat source equipment 5 and the supply of cold water from the heat source equipment 5 to the latent heat coil 11 or to both the latent heat coil 11 and the sensible heat coil 21. When cold water is supplied to the latent heat coil 11 and the sensible heat coil 21, as described above, for example, cold water discharged from the latent heat coil 11 may be mixed with cold water from the heat source equipment 5 and supplied to the sensible heat coil 21.

[0090] Furthermore, in the present embodiment, the case where the control unit 42 controls the latent heat unit 10 so that the temperature and humidity of the outside air or the return air, whichever has a higher absolute humidity, is adjusted in the latent heat unit 10 when the latent heat unit 10 and the sensible heat unit 20 are operated, has been mainly described, but this is not necessarily the case. For example, each unit to be operated may process a mixture of outside air and return air in a ratio determined by the control unit 42. In this case, each unit processes a mixture of air with the same ratio of outside air.

[0091] In addition, in this embodiment, we have described a case where various information is acquired by the acquisition unit 41, but if some of the information is not used by the control unit 42, the acquisition unit 41 does not need to acquire the information that is not used by the control unit 42.

[0092] Furthermore, in this embodiment, the case where the air conditioner 1 is equipped with the acquisition unit 41 and the control unit 42 has been mainly described, but this is not necessarily the case. The air conditioner 1 does not necessarily have to be equipped with the acquisition unit 41, and it does not necessarily have to be equipped with the control unit 42. If the air conditioner 1 is not equipped with the acquisition unit 41 or the control unit 42, each unit of the air conditioner 1 may be controlled, for example, by an external control device or the like, or may be controlled manually.

[0093] In addition, in the present embodiment, the latent heat unit 10, the sensible heat unit 20, and the blower unit 30 are mainly described as having return air blowers 13, 23, and 33, respectively, but this is not necessarily the case. For example, a unit that processes only outside air does not need to have a return air blower.

[0094] Furthermore, in the present embodiment, the air conditioner 1 has been mainly described as having one each of the latent heat unit 10, the sensible heat unit 20, and the blower unit 30, but this is not necessarily the case. The air conditioner 1 may have, for example, at least two of the latent heat unit 10, the sensible heat unit 20, and the blower unit 30. That is, the air conditioner 1 may have the latent heat unit 10 and the sensible heat unit 20, the latent heat unit 10 and the blower unit 30, or the sensible heat unit 20 and the blower unit 30. As an example, an air conditioner 1 used in an environment where sensible heat treatment is hardly required may have the latent heat unit 10 and the blower unit 30, but may not have the sensible heat unit 20. Furthermore, the air conditioner 1 may have, for example, two or more latent heat units 10, two or more sensible heat units 20, or two or more blower units 30. For example, in an air conditioner 1 equipped with two or more latent heat units 10, the degree of dehumidification can be controlled more precisely by changing the number of latent heat units 10 that are in operation.

[0095] Furthermore, in the air conditioner 1 according to this embodiment, the case where the blower unit 30 only blows air has been mainly described, but the blower unit 30 may further include a humidifier. Humidification may also be performed using the blower unit 30. For example, when the absolute humidity of the mixture of return air and outside air is lower than the target absolute humidity of the air-conditioned space 3, the control unit 42 may operate the blower unit 30 and control the blower unit 30 to humidify the air using the humidifier. For example, in commercial facilities and the like, air conditioning is sometimes performed in winter. In such cases, the sensible heat unit 20 and the blower unit 30 may be operated, and humidification may be performed using the blower unit 30.

[0096] Furthermore, in this embodiment, the case where the air-conditioning space 3 is cooled by the air-conditioning device 1 has been mainly described, but it goes without saying that the air-conditioning space 3 may also be heated using the air-conditioning device 1. When heating, hot water may be supplied to the latent heat unit 10 and the sensible heat unit 20, and the hot water may be used to raise the temperature of the air in the latent heat unit 10 and the sensible heat unit 20. Furthermore, for example, humidification may be performed using a humidifier in the air blower unit 30.

[0097] Furthermore, in the above embodiments, each process or function may be realized by centralized processing by a single device or a single system, or may be realized by distributed processing by multiple devices or multiple systems.

[0098] Furthermore, in the above-described embodiments, the transfer of information between components may be performed, for example, by one component outputting information and the other component receiving information if the two components transferring the information are physically different, or, if the two components transferring the information are physically the same, by moving from a processing phase corresponding to one component to a processing phase corresponding to the other component.

[0099] Furthermore, in the above-described embodiments, information related to the processing performed by each component, such as information accepted, acquired, selected, generated, transmitted, or received by each component, and information such as thresholds, formulas, and addresses used in processing by each component, may be temporarily or long-term stored in a recording medium (not shown), even if not explicitly stated in the above description. Furthermore, the storage of information in the recording medium (not shown) may be performed by each component or a storage unit (not shown). Furthermore, the reading of information from the recording medium (not shown) may be performed by each component or a reading unit (not shown).

[0100] Furthermore, in the above-described embodiments, if the information used by each component, such as thresholds, addresses, and various setting values ​​used by each component in processing, may be changed by the user, the user may or may not be able to change the information as appropriate, even if not explicitly stated in the above description. If the information is changeable by the user, the change may be realized, for example, by a receiving unit (not shown) that receives a change instruction from the user and a changing unit (not shown) that changes the information in accordance with the change instruction. The change instruction may be received by the receiving unit (not shown), for example, from an input device, by receiving information transmitted via a communication line, or by receiving information read from a predetermined recording medium.

[0101] Furthermore, in the above embodiment, when two or more components included in the air conditioning device 1 have a communication device, an input device, etc., the two or more components may physically have a single device, or may have separate devices.

[0102] In the above embodiments, each component may be configured with dedicated hardware, or a software-implementable component may be implemented by executing a program. For example, a software-implementable component may be implemented by a program execution unit such as a CPU reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory. During execution, the program execution unit may execute the program while accessing a storage unit or recording medium. The program may also be executed by being downloaded from a server or the like, or by being read from a predetermined recording medium (e.g., an optical disk, a magnetic disk, a semiconductor memory, etc.). The program may also be used as a program constituting a program product. The program may be executed by a single computer or multiple computers. That is, centralized processing or distributed processing may be performed.

[0103] Furthermore, the above-described embodiments are merely examples for specifically implementing the present invention, and are not intended to limit the technical scope of the present invention. The technical scope of the present invention is defined by the claims, not by the description of the embodiments, and is intended to include modifications within the literal scope of the claims and within the scope of equivalent meanings.

Claims

1. A latent heat unit having a latent heat coil, a latent heat blower which sends air whose temperature has been adjusted by the latent heat coil to an air-conditioned space, and a return air blower which at least one of exhausts air and blows air returned from the air-conditioned space to the latent heat blower; a sensible heat unit having a sensible heat coil, a sensible heat blower which sends air whose temperature has been adjusted by the sensible heat coil to the air-conditioned space, and a return air blower which at least one of exhausts air and blows air returned from the air-conditioned space to the sensible heat blower; a blower unit having a blower which sends air to the air-conditioned space, and a return air blower which at least one of exhausts air and blows air returned from the air-conditioned space to the blower; and a control unit which operates one or more of the latent heat unit, the sensible heat unit, and the blower unit; the latent heat coil adjusts the temperature of at least one of the outside air and the return air blown by the return air blower of the latent heat unit; the sensible heat coil adjusts the temperature of at least one of the outside air and the return air blown by the return air blower of the sensible heat unit; the blower blows at least one of the outside air and the return air blown by the return air blower of the blowing unit; when the latent heat unit and the sensible heat unit are at least operated by the control unit, cold water from a heat source equipment is supplied to the latent heat coil, and cold water obtained by mixing the cold water discharged from the latent heat coil and the cold water from the heat source equipment is supplied to the sensible heat coil; The control unit controls the mixing ratio of the cold water discharged from the latent heat coil and the cold water from the heat source equipment so that the cold water supplied to the sensible heat coil has a desired temperature when at least the latent heat unit and the sensible heat unit are operated in an air conditioning device.

2. A latent heat unit having a latent heat coil, a latent heat blower which sends air whose temperature has been adjusted by the latent heat coil to an air-conditioned space, and a return air blower which at least one of exhausts air and blows air returned from the air-conditioned space to the latent heat blower; a sensible heat unit having a sensible heat coil, a sensible heat blower which sends air whose temperature has been adjusted by the sensible heat coil to the air-conditioned space, and a return air blower which at least one of exhausts air and blows air returned from the air-conditioned space to the sensible heat blower; a blower unit having a blower which sends air to the air-conditioned space, and a return air blower which at least one of exhausts air and blows air returned from the air-conditioned space to the blower blower; an acquisition unit which acquires the temperature and humidity of the outside air, the temperature and humidity of the return air, the temperature and humidity of the air-conditioned space, the occupancy density of the air-conditioned space, and the carbon dioxide concentration of the air-conditioned space; an air conditioning unit comprising: a control unit that operates one or more of the latent heat unit, the sensible heat unit, and the blower unit based on the results acquired by the acquisition unit and a target temperature and target humidity of the air-conditioned space; wherein the latent heat coil adjusts a temperature of at least one of outside air and return air blown by a return air blower possessed by the latent heat unit; the sensible heat coil adjusts a temperature of at least one of outside air and return air blown by the return air blower possessed by the sensible heat unit; and the blower blows at least one of outside air and return air blown by the return air blower possessed by the blower unit.

3. The air conditioning device of claim 2, wherein the control unit: determines the volume of supply air supplied to the air-conditioned space based on the occupancy density in the air-conditioned space; determines the proportion of outside air contained in the supply air based on the carbon dioxide concentration in the air-conditioned space; determines whether to operate the latent heat unit based on the proportion of outside air, the temperature and humidity of the outside air, the temperature and humidity of the return air, the temperature and humidity of the air-conditioned space, and the target temperature and target humidity of the air-conditioned space; determines whether to operate the sensible heat unit based on the proportion of outside air, the temperature of the outside air, the temperature of the return air, the temperature of the air-conditioned space, and the target temperature of the air-conditioned space; determines whether to operate the blower unit based on the volume of supply air; and controls the latent heat unit, the sensible heat unit, and the blower unit in accordance with the determination results.

4. An air conditioning device as described in claim 3, wherein when the control unit operates the latent heat unit and the sensible heat unit, the control unit controls the temperature and humidity of the outside air or the return air, whichever has the higher absolute humidity, to be adjusted in the latent heat unit.

5. A method for controlling an air conditioning system equipped with a latent heat unit having a latent heat coil, a latent heat blower which sends air whose temperature has been adjusted by the latent heat coil to an air-conditioned space, and a return air blower which at least one of exhausts air and blows air returned from the air-conditioned space to the latent heat blower; a sensible heat unit having a sensible heat coil, a sensible heat blower which sends air whose temperature has been adjusted by the sensible heat coil to the air-conditioned space, and a return air blower which at least one of exhausts air and blows air returned from the air-conditioned space to the sensible heat blower; and a blower unit having a blower which sends air to the air-conditioned space, and a return air blower which at least one of exhausts air and blows air returned from the air-conditioned space to the blower, wherein the latent heat coil adjusts the temperature of at least one of the outside air and the return air blown by the return air blower of the latent heat unit, a step of controlling a sensible heat coil adjusting a temperature of at least one of outside air and return air blown by a return air blower of the sensible heat unit; the blower blowing at least one of outside air and return air blown by a return air blower of the blower unit; when the latent heat unit and the sensible heat unit are at least operated, cold water from a heat source equipment is supplied to the latent heat coil, and cold water obtained by mixing cold water discharged from the latent heat coil and cold water from the heat source equipment is supplied to the sensible heat coil; and a step of controlling a mixing ratio of the cold water discharged from the latent heat coil and the cold water from the heat source equipment so that the cold water supplied to the sensible heat coil has a desired temperature when the latent heat unit and the sensible heat unit are at least operated.

6. A method for controlling an air conditioning system equipped with a latent heat unit having a latent heat coil, a latent heat blower which sends air whose temperature has been adjusted by the latent heat coil to an air-conditioned space, and a return air blower which at least one of exhausts air and blows air returned from the air-conditioned space to the latent heat blower; a sensible heat unit having a sensible heat coil, a sensible heat blower which sends air whose temperature has been adjusted by the sensible heat coil to the air-conditioned space, and a return air blower which at least one of exhausts air and blows air returned from the air-conditioned space to the sensible heat blower; and a blower unit having a blower which sends air to the air-conditioned space, and a return air blower which at least one of exhausts air and blows air returned from the air-conditioned space to the blower blower, wherein the latent heat coil adjusts the temperature of at least one of the outside air and the return air blown by the return air blower of the latent heat unit, a sensible heat coil adjusting a temperature of at least one of the outside air and the return air blown by a return air blower provided in the sensible heat unit; the blower blowing at least one of the outside air and the return air blown by the return air blower provided in the blower unit; acquiring the temperature and humidity of the outside air, the temperature and humidity of the return air, the temperature and humidity of the air-conditioned space, the occupancy density in the air-conditioned space, and the carbon dioxide concentration in the air-conditioned space; and operating one or more of the latent heat unit, the sensible heat unit, and the blower unit based on the results acquired in the steps and a target temperature and target humidity for the air-conditioned space.

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