Air conditioning system

Abstract

To prevent the occurrence of inconveniences resulting from the operation of an air supply fan at a value lower than a lower limit value for inverter control without causing useless energy loss, by making effective use of surplus energy when the utilization rate of a room is greatly lower.SOLUTION: When total utilized-room air capacity required to supply air to all utilized rooms R1-R8 is equal to or lower than a lower limit air capacity in the case of operating an air supply fan 14 at a lower limit value for inverter control, an air conditioning control device 9 executes a lower limit value operation mode to operate the air supply fan 14 at the lower limit value for inverter control. In the lower limit value operation mode, during a time when the required opening number of air capacity control devices 7, 8 for the utilized rooms is smaller than the upper limit opening number of the air capacity control devices 7, 8 which can be opened in the lower limit value operation mode, it performs unutilized room ventilation processing for opening unopened air capacity control devices 7, 8 the number of which is according to a difference therebetween together with the required opening number of air capacity control devices 7, 8 to ventilate the unutilized rooms R1-R8.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an air conditioning system equipped with an air supply fan that supplies air to multiple rooms through an air supply duct, multiple air volume control devices that are connected in parallel to the air supply duct and maintain a constant air volume to each of the rooms, and an air conditioning control device that adjusts the total air supply volume by inverter controlling the air supply fan based on the utilization rate of the rooms and also controls the air volume control devices. [Background technology]

[0002] The background technology of the present invention is a technology that adjusts the total supply air volume by inverter controlling the supply air fans that supply air to multiple rooms through supply air ducts depending on the usage status of the rooms, and controls the opening and closing of multiple supply air dampers installed between the supply air ducts and the rooms (see, for example, Patent Document 1).

[0003] There is also a technology in which an air supply fan that supplies air to a first room and a second room through an air supply passage is inverter controlled, and a first constant air volume device and a second constant air volume device are provided in the air supply passage to supply a constant volume of air to the first room and the second room (see, for example, Patent Document 2).

[0004] Furthermore, there is a technology in which an intake fan that supplies air to multiple target rooms via an intake side main air duct and multiple intake side branch air ducts is inverter controlled, and the air volume to each target room is adjusted to a target air volume by a constant air volume device installed in each intake side branch air duct (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-108427 [Patent Document 2] Patent No. 5360844 [Patent Document 3] Patent No. 4428753 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, in hotels and office buildings with multiple rooms, room occupancy rates have sometimes dropped significantly due to measures such as restricting the flow of people to prevent infectious diseases. If such a significant drop in room utilization rate occurs in a hotel or office building that is equipped with an air conditioning system in which the supply air fan is inverter-controlled, the total air volume required to supply air to each room in use may fall below the minimum air volume that can be obtained when the supply air fan is operated at the lower limit of inverter control. In such a case, for example, if the air supply fan is operated at a value (rotation speed) lower than the lower limit of inverter control, problems may occur, such as the air supply fan motor generating heat or the inverter output becoming unstable. Furthermore, if the air supply fan is operated at the lower limit of inverter control to avoid these problems, this will result in unnecessary energy loss.

[0007] In view of this situation, the main objective of the present invention is to prevent malfunctions caused by the supply air fan being operated at a value lower than the lower limit of inverter control when the room utilization rate drops significantly by effectively utilizing surplus energy without incurring unnecessary energy loss. [Means for solving the problem]

[0008] A first characteristic configuration of the present invention is an air supply fan that supplies air to a plurality of rooms through an air supply duct; a plurality of air volume control devices connected in parallel to the air supply duct for maintaining constant air volumes to the respective rooms; an air conditioning control device that adjusts the total supply air volume by inverter-controlling the supply air fan based on the utilization rate of the room, and controls the air volume control device, The air conditioning control device performing an air volume comparison process to compare the total air volume required to supply air to all of the rooms being used with the minimum air volume that can be obtained when the air supply fan is operated at the minimum value of inverter control; If the total air volume of the user rooms is equal to or less than the lower limit air volume in the air volume comparison process, a lower limit operation mode is executed in which the air supply fan is operated at the lower limit value of the inverter control, In the lower limit operation mode, an opening number comparison process is performed to compare the required number of openings of the air volume control devices according to the room being used with the upper limit number of openings of the air volume control devices that can be opened in the lower limit operation mode, In the opening number comparison process, it is determined whether the required opening number is equal to or less than the upper limit opening number, If the required number of openings is the same as the upper limit number of openings in the opening number comparison process, the air volume control device of the room being used is opened and the air volume control device of the room not being used is kept closed, thereby performing an air volume maintenance process for the room being used to maintain a constant air volume; While the required number of openings is less than the upper limit number of openings in the opening number comparison process, an unused room ventilation process is performed in which a number of unopened air volume control devices corresponding to the difference are opened together with the required number of air volume control devices to ventilate the unused room.

[0009] According to this configuration, when the utilization rate of the room drops significantly and the total air volume of the used rooms mentioned above falls below the lower limit air volume, the air conditioning control device operates the supply air fan in the lower limit operation mode mentioned above, and in this lower limit operation mode, if a difference occurs between the required number of openings and the upper limit number of openings of the air volume control device mentioned above, the air conditioning control device performs the unused room ventilation process mentioned above while this difference exists. This makes it possible to avoid problems such as the air intake fan motor overheating or the inverter output becoming unstable, which can occur when the air intake fan is operated at a value (rotation speed) lower than the lower limit of inverter control. In addition, the excess air volume generated by the air supply fan during this operation is effectively utilized for ventilating unused rooms, thereby avoiding unnecessary energy loss. As a result, even if the room occupancy rate drops significantly, the air supply to each occupied room can be maintained at an appropriate level without incurring unnecessary energy loss, and unused rooms can be automatically ventilated, allowing for rational improvements to the hygiene of unused rooms, including measures to prevent infectious diseases.

[0010] A second characteristic configuration of the present invention is that, in the unused room ventilation process, the air conditioning control device sequentially ventilates the unused rooms by switching the unused air volume control devices to be opened in a predetermined order according to the difference between the required number of openings and the upper limit number of openings each time a predetermined time has elapsed since the unused air volume control devices were opened.

[0011] According to this configuration, while the aforementioned unused room ventilation process continues due to a significant drop in room utilization rate, the air conditioning control device automatically switches between unused rooms to be ventilated every specified time, thereby enabling multiple unused rooms to be ventilated efficiently without incurring unnecessary energy loss. As a result, hygiene improvements in unused rooms can be made more rationally.

[0012] A third characteristic configuration of the present invention is that the air conditioning control device The operating mode to be executed when the total air volume of the occupied rooms exceeds the lower limit air volume in the air volume comparison process can be selected from a normal operating mode and an unused room ventilation combined operating mode, In the normal operation mode, the total supply air volume is adjusted according to the utilization rate of the room, while maintaining a constant air volume to each of the rooms being used; In the unused room ventilation combined operation mode, the air supply fan is inverter-controlled and the air volume control device is controlled based on the total air volume contained in unused rooms, which is the total air volume of the used rooms plus the air volume supplied to a predetermined number of unused rooms, to maintain a constant air volume to each of the rooms that are in use, while opening the unopened air volume control devices corresponding to a predetermined number of unused rooms to ventilate the unused rooms.

[0013] According to this configuration, by selecting the unused room ventilation combined operation mode as the operation mode, the air conditioning control device will ventilate the unused room even when the room utilization rate is high. As a result, hygiene improvements in unused rooms can be made more effectively.

[0014] A fourth characteristic configuration of the present invention is that, in the unused room ventilation combined operation mode, the air conditioning control device switches the unused air volume control devices that are opened corresponding to a predetermined number of unused rooms in a predetermined order each time a predetermined time has elapsed since the opening of an unused air volume control device, thereby sequentially ventilating the unused rooms.

[0015] According to this configuration, if the unused room ventilation combined operation mode is selected as the operation mode, the air conditioning control device will automatically switch between unused rooms to be ventilated in sequence every time a specified time has elapsed, even if the room utilization rate is high. As a result, hygiene improvements in unused rooms can be made more effectively and rationally. [Brief explanation of the drawings]

[0016] [Figure 1] An explanatory diagram showing the air conditioning control status of guest rooms in normal operation mode and in the unused room ventilation combined operation mode [Figure 2] An explanatory diagram showing the air conditioning control status of a guest room in the second unused room ventilation combined operation state of the unused room ventilation combined operation mode. [Figure 3] An explanatory diagram showing the air conditioning control status of a guest room in the lower limit operation mode [Figure 4] Flowchart showing the control operation of the air conditioning control device in guest room air conditioning control [Figure 5] Flowchart showing the control operation of the air conditioning control device in guest room air conditioning control [Figure 6] Flowchart showing the control operation of the air conditioning control device in guest room air conditioning control [Figure 7] Flowchart showing the control operation of the air conditioning control device in guest room air conditioning control [Figure 8] Flowchart showing the control operation of the air conditioning control device in guest room air conditioning control [Figure 9] 10 is a flowchart showing the control operation of an air conditioning control device in guest room air conditioning control according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] As an example of a form for implementing the present invention, an embodiment in which the air conditioning system of the present invention is applied to a hotel, which is an example of an accommodation facility having a plurality of guest rooms as a plurality of rooms, will be described below with reference to the drawings. The air conditioning system according to the present invention can be applied to accommodation facilities other than hotels, and office buildings that have a plurality of rooms such as offices and conference rooms.

[0018] As shown in Figures 1 to 3, the air conditioning system illustrated in this embodiment is equipped with an AHU (air handling unit) 1 as an air conditioner that adjusts the temperature, humidity, etc. of the conditioned air supplied to multiple guest rooms R1 to R8, a heat source unit 2 that circulates and supplies a heat medium such as cold water or hot water to the AHU 1, an outside air duct 3 that directs outside air to the AHU 1, an air supply duct 4 that directs the conditioned air from the AHU 1 to each of the guest rooms R1 to R8, an exhaust duct 5 that directs the air in each of the guest rooms R1 to R8 to the outdoors, and an exhaust fan 6 that exhausts the air in each of the guest rooms R1 to R8 to the outdoors via the exhaust duct 5. Furthermore, the air conditioning system is equipped with a plurality of CAV units (an example of a constant air volume control device for supply air) 7 corresponding to the number of guest rooms, which are connected in parallel to the supply air duct 4 and maintain a constant air volume to each guest room R1 to R8, a plurality of CAV units (an example of a constant air volume control device for exhaust air) 8 corresponding to the number of guest rooms, which are connected in parallel to the exhaust duct 5 and maintain a constant air volume from each guest room R1 to R8, an air conditioning control device 9 that controls the guest room air conditioning of the air conditioning system, and an input device (not shown) that allows manual input of information necessary for guest room air conditioning control to the air conditioning control device 9.

[0019] In this embodiment, in order to make it easier to understand the air conditioning system of the present invention, as shown in Figures 1 to 3, an example is shown in which the air conditioning system of the present invention is applied to a hotel in which each of the guest rooms R1 to R8 has the same size and each of the guest rooms R1 to R8 is equipped with one CAV unit 7, 8 for supplying and exhausting air.However, this is not limited to this, and the air conditioning system of the present invention can also be applied to, for example, a hotel in which there are a plurality of guest rooms of different sizes and the number of CAV units 7, 8 equipped in each guest room varies depending on the size of each room. Furthermore, the air conditioning system may be equipped with, for example, a return air duct that returns exhaust air from each guest room R1 to R8 to the AHU 1, and the air volume control devices 7, 8 for supply and exhaust are not limited to CAV units, but may also be, for example, VAV units (variable air volume control devices) or motor dampers.

[0020] Although not shown in the figure, each CAV unit 7, 8 is equipped with a damper that adjusts the amount of air passing through it, an electric motor that adjusts the opening of the damper, a wind speed sensor that detects the wind speed within each CAV unit 7, 8, and a control device that controls the operation of the electric motor based on detection by the wind speed sensor, etc., to adjust the opening of the damper.

[0021] As shown in Figures 1 to 3, AHU 1 is equipped with an air filter 11 that collects dust and other particles contained in the outside air, a heat exchanger 12 that adjusts the temperature of the conditioned air supplied to each guest room R1 to R8 by heat exchange with the heat medium from heat source unit 2, a humidifier 13 that adjusts the humidity of the conditioned air supplied to each guest room R1 to R8 using steam from heat source unit 2, and a supply air fan 14 that supplies conditioned air to each guest room R1 to R8 via supply air duct 4.

[0022] The air conditioning control device 9 is connected via a communication network to a central monitoring device 20, which monitors and controls all systems within the hotel. The air conditioning control device 9 calculates the occupancy rates of guest rooms R1 to R8 (hereinafter referred to as "guest room occupancy rates") based on various information related to the guest room air conditioning control of the air conditioning system obtained from input devices, central monitoring device 20, etc., and based on the calculated guest room occupancy rates, etc., it inverter-controls the supply air fan 14 and the exhaust fan 6 to adjust the total supply air volume from the supply air fan 14 and the total exhaust air volume from the exhaust fan 6, and also controls the supply and exhaust CAV units 7, 8 to adjust the air balance in each of the guest rooms R1 to R8.

[0023] The intake fan 14 and the exhaust fan 6 are each set to a lower limit when they are inverter controlled, and by operating the intake fan 14 and the exhaust fan 6 at a value above this lower limit, it is possible to avoid problems such as heat generation in the fan motor and instability in the inverter output.

[0024] The air conditioning system may not be provided with the exhaust fan 6, as long as it is possible to properly adjust the air balance in each of the guest rooms R1 to R8 without providing the exhaust fan 6.

[0025] The air conditioning control device 9 is equipped with a memory unit (not shown) that stores various information necessary for the air conditioning control of the guest rooms of the air conditioning system. The memory unit stores various information such as a plurality of operating modes that enable suitable guest room air conditioning control according to the guest room occupancy rate, appropriate air volumes individually set for each guest room R1 to R8, the number of CAV units 7, 8 installed, identification information for each CAV unit 7, 8 for each guest room R1 to R8, the lower limit values ​​when the supply air fan 14 and the exhaust fan 6 are inverter controlled, the lower limit air volume obtained when the supply air fan 14 and the exhaust fan 6 are operated at the lower limit value of inverter control, and the upper limit number of openings for each CAV unit 7, 8 that can be opened at that lower limit air volume.

[0026] As described above, in this embodiment, the hotel to which the air conditioning system of the present invention is applied is exemplified as one in which each of the guest rooms R1 to R8 has the same size and each is equipped with one CAV unit 7, 8 for supplying and exhausting air, so the appropriate airflow rates for each of the guest rooms R1 to R8 stored in the memory are the same and each of the guest rooms R1 to R8 is equipped with one CAV unit 7, 8. Furthermore, the upper limit number of CAV units 7, 8 that can be opened at the minimum airflow rate is set to two.

[0027] The memory unit of the air conditioning control device 9 stores multiple operating modes: a normal operating mode (see FIG. 1), an unused room ventilation combined operating mode (see FIGS. 1-2), and a lower limit operating mode (see FIG. 3). The normal operating mode and the unused room ventilation combined operating mode are activated when the total air volume required to supply air to the occupied rooms (R2, R5, and R6 in FIGS. 1-2) exceeds the aforementioned lower limit air volume. The hotel manager or other personnel can select one of these modes by operating an operating mode selector (not shown) provided on the input device. The lower limit operating mode is activated when the total air volume of the occupied rooms falls below the lower limit air volume. The memory unit also stores a preset number of ventilated rooms, which is the number of unused rooms to be ventilated in the unused room ventilation combined operating mode, as well as the ventilation priority of unused rooms to be used in the unused room ventilation combined operating mode and the lower limit operating mode.

[0028] 1 to 3, in the present embodiment, the number of rooms set for ventilation in the unused room ventilation combined operation mode is set to two, and the ventilation priority of unused rooms is set to ventilate rooms in descending order of room number, but this is not limiting, and the number of rooms set for ventilation may be set to one room or three or more rooms, or may be increased or decreased according to the number of occupied rooms so that the fewer the number of occupied rooms, the greater the number of rooms set for ventilation. The ventilation priority of unused rooms may be set, for example, to ventilate rooms in ascending order of room number, or rooms in ascending order of smallest room number.

[0029] Hereinafter, the control operation of the air conditioning control device 9 in controlling the air conditioning of a passenger compartment of an air conditioning system will be described with reference to the explanatory diagrams of FIGS. 1 to 3 and the flowcharts of FIGS.

[0030] As shown in FIG. 4, the air conditioning control device 9 first performs an information acquisition process to acquire various information necessary for guest room air conditioning control (step #1). Based on the acquired information, the air conditioning control device 9 then performs a calculation process to calculate the total air volume required to supply air to all guest rooms (guest rooms R2, R5, and R6 in FIGS. 1 and 2, and guest room R2 in FIG. 3) and the room occupancy rate (step #2). Specifically, in the information acquisition process, the air conditioning control device 9 receives reservation information for each guest room R1-R8 held by the hotel's room reservation system via the central monitoring device 20, and acquires various information, such as the number and room numbers of currently occupied and unused guest rooms, based on the received reservation information. Then, in the calculation process, the air conditioning control device 9 calculates the total air volume required for the rooms based on the appropriate air volume for each guest room R1-R8 stored in the memory unit and the number and room numbers of the occupied rooms acquired in the information acquisition process. The room occupancy rate is also calculated based on the number of occupied rooms among all the guest rooms acquired in the information acquisition process.

[0031] In addition, in the information acquisition process, in addition to the reservation information for each guest room R1 to R8, various information may be acquired based on, for example, check-in and check-out information for each guest room R1 to R8 entered into a front desk terminal owned by the hotel's entry and exit management system, or entry and exit information for each guest room R1 to R8 obtained from a card reader installed in each guest room R1 to R8. Furthermore, when adjusting the air balance of each guest room R1 to R8, the supply air volume to each guest room R1 to R8 is the same as the exhaust air volume from each guest room R1 to R8, so the total air volume of the rooms used calculated by the above calculation process is the total supply air volume to each guest room used as well as the total exhaust air volume from each guest room used.

[0032] Next, the air conditioning control device 9 performs an air volume comparison process to compare the total air volume of the use rooms calculated in the calculation process with the lower limit air volume stored in the memory unit (step #3). Specifically, in this air volume comparison process, the total air volume of the use rooms is compared with the lower limit air volume to determine whether the total air volume of the use rooms exceeds the lower limit air volume.

[0033] If the air volume comparison process indicates that the total air volume of the occupied rooms exceeds the lower limit air volume (YES in step #3 of FIG. 4), the air conditioning control device 9 performs an operation mode determination process to determine the operation mode selected by the operation mode selection unit (step #4). Specifically, as described above, since the operation mode selected by the operation mode selection unit is either the normal operation mode or the unused room ventilation combined operation mode, the operation mode determination process determines whether the selected operation mode is the normal operation mode. If the operation mode determination process indicates that the operation mode is the normal operation mode (YES in step #4 of FIG. 4), the air conditioning control device 9 performs a normal operation mode switching process to switch the operation mode of the air conditioning system to the normal operation mode (step #5). If the operation mode is not the normal operation mode (NO in step #4 of FIG. 4), the selected operation mode is the unused room ventilation combined operation mode, so the air conditioning control device 9 performs an unused room ventilation combined operation mode switching process to switch the operation mode of the air conditioning system to the unused room ventilation combined operation mode (step #6).

[0034] If the total air volume of the rooms in use does not exceed the lower limit air volume in the air volume comparison process of step #3 (No in step #3 of Figure 4), the air conditioning control device 9 performs a lower limit operation mode switching process to switch the operation mode of the air conditioning system to the lower limit operation mode (step #7) because the total air volume of the rooms in use is below the lower limit air volume.

[0035] In normal operation mode, as shown in Fig. 4, the air conditioning control device 9 performs a total air volume adjustment process (step #8) in which it inverter-controls the supply air fan 14 and the exhaust fan 6 to adjust the total supply air volume of the supply air fan 14 and the total exhaust air volume of the exhaust fan 6 based on the total air volume of the occupied rooms calculated in the calculation process. Furthermore, based on the room numbers of the occupied and unused rooms acquired in the information acquisition process and the identification information of each CAV unit 7, 8 stored in the memory, it performs a room air volume maintenance process (step #9) in which it opens the CAV units 7, 8 corresponding to the occupied rooms (R2, R5, R6 in Fig. 1) and closes the CAV units 7, 8 corresponding to the unused rooms (R1, R3, R4, R7, R8 in Fig. 1) to maintain a constant air volume to the occupied rooms. As a result, in normal operation mode, the air conditioning system operates in a normal operating state in which the total air supply volume of the air supply fan 14 and the total air exhaust volume of the exhaust fan 6 are adjusted according to the room occupancy rate, while maintaining a constant air volume to the occupied rooms.

[0036] In the unused room ventilation combined operation mode, as shown in Figures 5 and 6, the air conditioning control device 9 first performs the total air volume adjustment process and the used room air volume maintenance process (steps #10 and #11) described above, thereby operating the air conditioning system in the normal operation state described above (see Figure 1). It also performs an unused room determination process (step #12) to determine whether or not there are unused rooms based on the number of unused rooms acquired in the information acquisition process. If there are no unused rooms (No in step #12 of Figure 5, meaning the system is fully booked), it continues the total air volume adjustment process and the used room air volume maintenance process described above (step #13), thereby continuing the normal operation state.

[0037] If the air conditioning control device 9 determines in the unused room determination process that there is an unused room (Yes in step #12 of Figure 5), it performs an elapsed time determination process to determine whether the unused time of the existing unused room has exceeded a predetermined time requiring ventilation (step #14).If the unused time has not exceeded the predetermined time (No in step #14 of Figure 5), it continues the total air volume adjustment process and the used room air volume maintenance process described above (step #13), thereby continuing the normal operating state until the unused time has exceeded the predetermined time requiring ventilation.

[0038] When the unused time has exceeded a predetermined time in the elapsed time determination process (if Yes in step #14 in FIG. 5), the air conditioning control device 9 performs a room number comparison process (step #15) to compare the number of existing unused rooms (hereinafter referred to as the number of existing unused rooms) with the set number of ventilation rooms stored in the memory unit. Specifically, in this room number comparison process, the number of existing unused rooms (5 rooms in FIG. 1) is compared with the set number of ventilation rooms (2 rooms in this embodiment) to determine whether the number of existing unused rooms is equal to or less than the set number of ventilation rooms.

[0039] If the number of existing unused guest rooms is less than the set number of ventilation rooms in the room number comparison process (if Yes in step #15 and in this embodiment the number of existing unused guest rooms is 1 to 2), the air conditioning control device 9 calculates the appropriate air volume for the existing unused guest rooms as the total air volume for unused rooms, and performs a first total air volume calculation process for unused rooms to calculate the first total air volume for unused rooms by adding this total air volume for unused rooms to the total air volume for used rooms mentioned above (step #16).Then, by inverter controlling the supply air fan 14 and the exhaust fan 6 based on the calculated first total air volume for unused rooms, the air conditioning control device 9 performs a first total air volume adjustment process for unused rooms to adjust the total supply air volume of supply fan 14 and the total exhaust air volume of exhaust fan 6 to appropriate air volumes taking into account the number of rooms subject to air volume adjustment (the number of used guest rooms plus the number of existing unused guest rooms) and the appropriate air volume for each room subject to air volume adjustment (step #17). In addition, based on the room numbers of the unused guest rooms acquired in the information acquisition process and the identification information of each CAV unit 7, 8 stored in the memory unit, a first unused room ventilation process is started in which, in addition to each CAV unit 7, 8 corresponding to the used guest rooms, each CAV unit 7, 8 corresponding to a predetermined number of unused guest rooms is opened to ventilate the unused guest rooms (step #18). This allows the operating state of the air conditioning system to be switched from a normal operating state to a first unused room ventilation combined operating state, which ventilates the number of unused rooms (a predetermined number) that exist while maintaining a constant, appropriate air volume for the supply and exhaust air volume for each occupied room.

[0040] The air conditioning control device 9 then performs an elapsed time determination process to determine whether a predetermined ventilation time has elapsed since switching to the first unused-room ventilation combined operation state (step #19). If the predetermined ventilation time has not elapsed (No in step #19 of FIG. 5), the first unused-room ventilation combined operation state continues until the predetermined ventilation time has elapsed. If the predetermined ventilation time has elapsed (Yes in step #19 of FIG. 5), the air conditioning control device 9 closes each CAV unit 7, 8 corresponding to the predetermined number of unused rooms, terminating the first unused-room ventilation process (step #20), and performs the total air volume adjustment process described above (step #21), thereby switching the operating state of the air conditioning system from the first unused-room ventilation combined operation state to normal operation.

[0041] If the number of unused guest rooms is greater than the set number of ventilation rooms in the room number comparison process of step #15 (No in step #15 of FIG. 5), the air conditioning control device 9 calculates the appropriate air volume for the unused guest room (guest room R7, R8 in FIG. 2) with the highest set number of ventilation rooms at the current ventilation priority level based on the ventilation priority of the unused guest rooms stored in the memory unit as shown in FIG. 7, and calculates the second unused room-included total air volume by adding this unused room total air volume to the used room total air volume. A second unused-room total air volume calculation process is performed to calculate the second unused-room total air volume (step #22), and then inverter-controlling the supply air fan 14 and the exhaust fan 6 based on the calculated second unused-room total air volume adjusts the total supply air volume of the supply air fan 14 and the total exhaust air volume of the exhaust fan 6 to the air volume calculated based on the number of rooms subject to air volume adjustment (the number of unused rooms with the set ventilation chambers) plus the number of unused rooms with the set ventilation chambers, and the appropriate air volume for each room (step #23). Based on the room numbers of the unused rooms acquired in the information acquisition process, the identification information of the CAV units 7 and 8 stored in the memory, and the ventilation order of the unused rooms, a second unused-room ventilation process is initiated to ventilate the unused rooms with the highest set ventilation chambers at the current stage (rooms R7 and R8 in FIG. 2) by opening the CAV units 7 and 8 corresponding to the used rooms, as well as the CAV units 7 and 8 corresponding to the unused rooms with the highest set ventilation chambers (step #24). This allows the operating state of the air conditioning system to be switched from the normal operating state (see Figure 1) to the second unused room ventilation combined operating state (see Figure 2), which ventilates the unused rooms with the highest ventilation priority set (predetermined number) while maintaining the supply and exhaust air volume for each occupied room at a constant, appropriate air volume.

[0042] The air conditioning control device 9 then performs an elapsed time determination process to determine whether a predetermined ventilation time has elapsed since the opening of each CAV unit 7, 8 corresponding to the unused guest room (step #25). If the predetermined ventilation time has not elapsed (No in step #25 of FIG. 7), the air conditioning control device 9 continues the second unused room ventilation combined operation state until the predetermined ventilation time has elapsed. If the predetermined ventilation time has elapsed (Yes in step #25 of FIG. 7), the air conditioning control device 9 performs a CAV unit closing process to close each CAV unit 7, 8 of the unused guest room that was opened, a ventilation order update process to sequentially move up the ventilation order of unused guest rooms from third place onwards and update the order of the unused guest room after ventilation to the lowest, and the unused room determination process described above (steps #26-28). If the unused room determination process determines that there is an unused guest room (Yes in step #28 of FIG. 7), the air conditioning control device 9 proceeds to the room number comparison process of step #15 of FIG. 5. As a result, when the number of unused rooms is greater than the set number of ventilation rooms in the unused room ventilation combined operation mode, the supply and exhaust air volume for each occupied room can be maintained constant at an appropriate air volume, as shown in Figure 2, while the unused rooms of the set number of ventilation rooms are automatically ventilated in a predetermined order in a cycle.

[0043] If there are no unused rooms in the unused room determination process of step #28 (if the answer is No in step #28 of Figure 7 and the room is fully booked), the air conditioning control device 9 performs the total air volume adjustment process described above (step #29), thereby switching the operating state of the air conditioning system from the second unused room ventilation combined operating state to the normal operating state.

[0044] In the lower limit operation mode, as shown in FIG. 8, the air conditioning control device 9 performs a lower limit operation process in which the supply air fan 14 and the exhaust fan 6 are operated at the lower limit of inverter control (step #30). Furthermore, the air conditioning control device 9 performs a required number of openings calculation process in which the required number of openings for each CAV unit 7, 8 corresponding to the guest room (R2 in FIG. 3) is calculated based on the room number of the guest room acquired in the information acquisition process and the identification information of each CAV unit 7, 8 stored in the storage unit (step #31). The air conditioning control device 9 then performs a number of openings comparison process in which the calculated required number of openings is compared with the upper limit of openings for each CAV unit 7, 8 stored in the storage unit (step #32). Specifically, in this number of openings comparison process, the required number of openings for each CAV unit 7, 8 is compared with the upper limit of openings (two in this embodiment) to determine whether the required number of openings is the same as the upper limit of openings. Then, if the required number of openings for each CAV unit 7, 8 is the same as the upper limit number of openings in the opening number comparison process (Yes in step #32 of Figure 8), each CAV unit 7, 8 corresponding to the occupied room is opened and each CAV unit 7, 8 corresponding to the unused room is closed to perform occupied room air volume maintenance process to maintain a constant air volume to the occupied room (step #33).

[0045] If the required number of openings for each CAV unit 7, 8 in the opening number comparison process in step #32 is less than the upper limit number of openings (No in step #32 in FIG. 8), the air conditioning control device 9 performs a difference number calculation process to calculate the difference between the required number of openings and the upper limit number of openings, and also performs the occupied room air volume maintenance process described above (steps #34, #35). Furthermore, based on the calculated difference number, the room numbers of the occupied and unused rooms acquired in the information acquisition process, the identification information of each CAV unit 7, 8 stored in the memory, and the ventilation priority of the unused room, the air conditioning control device 9 starts a third unused room ventilation process (step #36) in which, among the CAV units 7, 8 corresponding to the unused rooms that would not be opened in the occupied room air volume maintenance process in step #35, the CAV units 7, 8 of the unused room currently with the highest ventilation priority (room R8 in FIG. 3) are opened to ventilate the unused room. Next, the aforementioned elapsed time determination process is performed to determine whether a predetermined ventilation time has elapsed since the CAV units 7 and 8 corresponding to the unused guest room with the highest ventilation priority were opened (step #37). If the predetermined ventilation time has not elapsed (No in step #37 of FIG. 8), the third unused room ventilation process is continued until the predetermined ventilation time has elapsed. If the predetermined ventilation time has elapsed (Yes in step #37 of FIG. 8), the CAV unit closing process is performed to close the CAV units 7 and 8 of the unused guest room that were opened, and the ventilation priority update process is performed to sequentially move up the ventilation priority of the unused guest rooms from second to last (steps #38 and #39). As a result, when the total air volume required to supply air to all occupied guest rooms falls below the lower limit air volume obtained when the intake fan 14 and exhaust fan 6 are operated at the lower limit of inverter control, the operating mode of the air conditioning system is switched to the lower limit operating mode (see Figure 3). In this lower limit operating mode, while the required number of openings of each CAV unit 7, 8 corresponding to the occupied guest rooms is less than the upper limit number of openings of each CAV unit 7, 8 in the lower limit operating mode, as shown in Figure 3, a number of unopened CAV units 7, 8 corresponding to the difference between the required number of openings and the required number of openings can be opened together to ventilate the unused guest rooms.In addition, each time a predetermined ventilation time has elapsed since the opening of each CAV unit 7, 8 corresponding to the unused guest room with the highest ventilation priority, the unopened CAV units 7, 8 that are opened according to the difference between the required number of openings and the upper limit number of openings can be switched in a predetermined ventilation priority order, allowing the unused guest rooms to be ventilated sequentially.

[0046] In short, in the air conditioning system exemplified in this embodiment, the air conditioning control device 9 performs an air volume comparison process that compares the total air volume of the occupied rooms required to supply air to all occupied rooms with the lower limit air volume obtained when the supply air fan 14 and the exhaust fan 6 are operated at the lower limit of inverter control. If this air volume comparison process results in the total air volume of the occupied rooms being below the lower limit air volume, a lower limit operation mode is executed in which the supply air fan 14 and the exhaust fan 6 are operated at the lower limit of inverter control. In this lower limit operation mode, an opening number comparison process is performed that compares the required number of openings of each CAV unit 7, 8 corresponding to the occupied rooms with the upper limit number of openings of each CAV unit 7, 8 that can be opened in the lower limit operation mode. If this opening number comparison process results in the required number of openings being less than the upper limit number, a third unused room ventilation process is performed in which a number of unopened CAV units 7, 8 corresponding to the difference between the required number of openings is opened together with the required number of CAV units 7, 8 to ventilate the unused rooms. In this third unused room ventilation process, the air conditioning control device 9 is configured to sequentially ventilate the unused rooms by switching the unused CAV units 7, 8 to be opened in a predetermined order according to the difference between the required number of openings and the upper limit number of openings each time a predetermined ventilation time (predetermined time) has elapsed since opening each unused CAV unit 7, 8.

[0047] With the above configuration, if the occupancy rate of rooms in the hotel drops significantly and the total air volume required to supply air to all occupied rooms falls below the lower limit air volume, the air conditioning control device 9 will operate the supply air fan 14 and the exhaust fan 6 in lower limit operation mode, and if, in this lower limit operation mode, a difference occurs between the required number of openings and the upper limit number of openings of each CAV unit 7, 8, then, while this difference exists, the air conditioning control device 9 will perform a third unused room ventilation process in which it automatically switches between unused rooms to be ventilated every time a specified ventilation time has elapsed.

[0048] This makes it possible to avoid problems such as the motors of the air supply fan 14 and the exhaust fan 6 overheating or the inverter output becoming unstable, which can occur when the air supply fan 14 and the exhaust fan 6 are operated at a value lower than the lower limit of the inverter control.

[0049] Furthermore, the excess air volume generated by the air supply fan 14 and the exhaust fan 6 during this operation is effectively utilized for ventilating unused guest rooms, thereby avoiding unnecessary energy loss.

[0050] As a result, even if the occupancy rate of rooms drops significantly, the air supply to each occupied room can be maintained at an appropriate level without incurring unnecessary energy loss, and unused rooms can be automatically ventilated, allowing for rational improvements to the hygiene of unused rooms, including measures to prevent infectious diseases.

[0051] Furthermore, in the air conditioning system exemplified in this embodiment, the operating mode to be executed when the total air volume of the occupied rooms required to supply air to all occupied guest rooms exceeds a lower limit air volume can be selected between a normal operating mode and an unused room ventilation combined operating mode.In the unused room ventilation combined operating mode, the air conditioning control device 9 is configured to inverter-control the supply air fan 14 and the exhaust fan 6 and control each CAV unit 7, 8 based on the total air volume contained in the unused rooms, which is the total air volume of the occupied rooms mentioned above plus the air volume supplied to a predetermined number of unused guest rooms, to perform a first unused room ventilation process or a second unused room ventilation process in which the unused CAV units 7, 8 corresponding to a predetermined number of unused guest rooms are opened to ventilate the unused guest rooms while maintaining a constant air volume to each occupied guest room. In the second unused room ventilation process, the air conditioning control device 9 is configured to sequentially ventilate the unused rooms by switching the unused CAV units 7, 8 that are opened corresponding to a predetermined number of unused rooms in a predetermined order each time a predetermined ventilation time (predetermined time) has elapsed since opening each unused CAV unit 7, 8.

[0052] As a result, even if the total air volume required to supply air to all occupied rooms exceeds the lower limit air volume, by selecting the unused room ventilation combined operation mode as the operating mode, the air conditioning control device 9 will ventilate unused rooms even when the room occupancy rate is high.In the second unused room ventilation process, the unused rooms to be ventilated are automatically switched in sequence every time a specified ventilation time has elapsed, allowing for effective and rational improvements to the hygiene of unused rooms.

[0053] [Another embodiment] Another embodiment of the present invention will now be described. The configurations of the other embodiments described below are not limited to being applied alone, but can also be applied in combination with the configurations of the above-described embodiment or other other embodiments.

[0054] (1) In the above embodiment, the second unused room ventilation process and the third unused room ventilation process are exemplified as the air conditioning control device 9 switching between the unused CAV units (air volume control devices) 7, 8 in a predetermined order each time a predetermined ventilation time (predetermined time) has elapsed since the opening of each unused CAV unit (air volume control device) 7, 8, thereby ventilating the unused rooms in sequence. However, this is not limited to this, and the process may also be, for example, ventilating unused rooms arbitrarily selected by the administrator.

[0055] (2) In the above embodiment, the ventilation mode for unused rooms combined with ventilation for unused rooms, which is performed when the number of unused rooms is greater than the set number of ventilation rooms, is an example of a circulating ventilation mode in which the ventilation of unused rooms is circulated in a predetermined order. However, this is not limited to this, and for example, the ventilation mode for unused rooms may be a circulating ventilation mode in which the ventilation of unused rooms is circulated in a predetermined order.

[0056] (3) In the above embodiment, the combined operation mode for ventilation of unused rooms is exemplified as one ventilation mode for unused rooms (circulation ventilation mode) that is performed when the number of unused rooms is greater than the set number of ventilation rooms. However, this is not limited to this, and the ventilation mode for unused rooms may be configured to be selectable between a circulation ventilation mode in which the ventilation of unused rooms is circulated in a predetermined order, and a circulation ventilation mode in which the ventilation of unused rooms is circulated in a predetermined order.

[0057] To elaborate on the above configuration, the memory unit of the air conditioning control device 9 is provided with two ventilation modes for the unused guest rooms mentioned above: a one-way ventilation mode and a circulating ventilation mode, and these can be selected alternatively by, for example, a hotel manager operating a ventilation mode selection unit provided in an input device.

[0058] Hereinafter, the control operation of the air conditioning control device 9 regarding switching of the ventilation mode of the unused guest rooms will be described with reference to the flowchart of FIG. Note that the flowchart of Figure 9 is the guest room air conditioning control exemplified in the above embodiment, with steps #28-29 described in the flowchart of Figure 7 replaced with steps #40-43. Therefore, the following description will begin with the stage in the above-mentioned guest room air conditioning control where the second unused room ventilation process is initiated at step #24 of Figure 7 and the operating state of the air conditioning system is switched from the normal operating state to the second unused room ventilation combined operating state.

[0059] When the second unused room ventilation process is started in step #24, the air conditioning control device 9 performs an elapsed time determination process to determine whether a predetermined ventilation time has elapsed since the CAV units 7 and 8 corresponding to the unused guest rooms were opened (step #25). If the predetermined ventilation time has not elapsed (No in step #25 of FIG. 9), the air conditioning control device 9 continues the second unused room ventilation combined operation state until the predetermined ventilation time has elapsed. If the predetermined ventilation time has elapsed (Yes in step #25 of FIG. 9), the air conditioning control device 9 performs a CAV unit closing process to close the CAV units 7 and 8 of the unused guest rooms that were opened, a ventilation order update process to sequentially move up the ventilation order of unused guest rooms from third place onwards and update the order of the unused guest rooms after ventilation to the lowest, and a ventilation complete cycle determination process to determine whether the ventilation of the unused guest rooms has been cycled in the predetermined order (steps #26-27, #40). If the unused rooms have not been fully ventilated (No in step #40 of Figure 9), the aforementioned unused room discrimination process is performed (step #41), and if the unused room discrimination process finds that there are unused rooms (Yes in step #41 of Figure 9), the process transitions to the room number comparison process of step #15 of Figure 5, and ventilation of the unused rooms continues.

[0060] If the ventilation cycle determination process in step #40 determines that the ventilation of the unused guest rooms has been completed (Yes in step #40 in FIG. 9), the air conditioning control device 9 performs a ventilation mode determination process to determine the ventilation mode selected by the ventilation mode selection unit (step #42). Specifically, as described above, since the ventilation mode selected by the ventilation mode selection unit is either the cycle ventilation mode or the circulating ventilation mode, this ventilation mode determination process determines whether the selected operating mode is the cycle ventilation mode. If the ventilation mode determination process determines that the ventilation mode is the cycle ventilation mode (Yes in step #42 in FIG. 9), the air conditioning control device 9 performs the total air volume adjustment process described above (step #43), thereby switching the operating state of the air conditioning system from the second unused room ventilation combined operating state to the normal operating state and terminating the ventilation of the unused guest rooms.

[0061] If the ventilation mode is not the circulating ventilation mode in the ventilation mode determination process of step #42 (No in step #42 of Figure 9), the air conditioning control device 9 transitions to the unused room determination process of step #41 since the selected ventilation mode is the circulating ventilation mode.If the unused room determination process determines that there are unused guest rooms (Yes in step #41 of Figure 9), it transitions to the room number comparison process of step #15 of Figure 5 and continues ventilation of the unused guest rooms.

[0062] If there are no unused rooms in the unused room determination process of step #41 (if the answer is No in step #41 in Figure 9 and the room is fully booked), the air conditioning control device 9 transitions to the total air volume adjustment process of step #43, thereby switching the operating state of the air conditioning system from the second unused room ventilation combined operating state to the normal operating state.

[0063] In other words, when the single-loop ventilation mode is selected as the ventilation mode for unused guest rooms in the unused room ventilation combined operation mode, if the number of unused guest rooms is greater than the set number of ventilation rooms, the air conditioning system will continue to operate in the second unused room ventilation combined operation state until the unused guest rooms have been ventilated in the specified order, so that the set number of unused guest rooms can be automatically ventilated in the specified order while maintaining a constant, appropriate supply and exhaust air volume for each occupied guest room, as shown in Figure 2. Then, once the unused guest rooms have been ventilated in the specified order, the air conditioning system will switch from the second unused room ventilation combined operation state to the normal operation state, and the ventilation of the unused guest rooms will automatically end.

[0064] On the other hand, when the recirculation ventilation mode is selected in the unused room ventilation combined operation mode, if the number of unused rooms is greater than the set number of rooms to be ventilated, the second unused room ventilation combined operation state will continue during that time, so that the supply and exhaust air volume for each occupied room can be maintained constant at an appropriate air volume, while the set number of unused rooms to be ventilated can be automatically ventilated in a predetermined order in a cyclical manner. From this point of view, for example, in a large hotel with many rooms, if the room occupancy rate declines over the long term, selecting the recirculation ventilation mode will allow unused rooms to be ventilated periodically in the set number of rooms, which will rationally improve the hygiene of unused rooms, including infection control. [Explanation of symbols]

[0065] 4 Air supply duct 7 CAV unit (air volume control device) 8 CAV unit (air volume control device) 9 Air conditioning control device 14 Air supply fan R1 Guest Room (Room) R8 Guest Room (Room)

Claims

1. an air supply fan that supplies air to a plurality of rooms through an air supply duct; a plurality of air volume control devices connected in parallel to the air supply duct for maintaining constant air volumes to the respective rooms; an air conditioning control device that adjusts the total supply air volume by inverter-controlling the supply air fan based on the utilization rate of the room, and controls the air volume control device, The air conditioning control device performing an air volume comparison process to compare the total air volume required to supply air to all of the rooms being used with the minimum air volume that can be obtained when the air supply fan is operated at the minimum value of inverter control; If the total air volume of the user rooms is equal to or less than the lower limit air volume in the air volume comparison process, a lower limit operation mode is executed in which the air supply fan is operated at the lower limit value of the inverter control, In the lower limit operation mode, an opening number comparison process is performed to compare the required number of openings of the air volume control devices according to the room being used with the upper limit number of openings of the air volume control devices that can be opened in the lower limit operation mode, In the opening number comparison process, it is determined whether the required opening number is equal to or less than the upper limit opening number, If the required number of openings is the same as the upper limit number of openings in the opening number comparison process, the air volume control device of the room being used is opened and the air volume control device of the room not being used is kept closed, thereby performing an air volume maintenance process for the room being used to maintain a constant air volume; An air conditioning system that performs an unused room ventilation process in which, while the required number of openings is less than the upper limit number of openings in the opening number comparison process, a number of unopened air volume control devices corresponding to the difference between the required number of openings and the upper limit number of openings are opened together with the required number of air volume control devices to ventilate the unused room.

2. The air conditioning system of claim 1, wherein, in the unused room ventilation process, the air conditioning control device sequentially ventilates the unused rooms by switching the unused air volume control devices to be opened in a predetermined order according to the difference between the required number of openings and the maximum number of openings each time a predetermined time has elapsed since the unused room ventilation process was started.

3. The air conditioning control device The operating mode to be executed when the total air volume of the occupied rooms exceeds the lower limit air volume in the air volume comparison process can be selected from a normal operating mode and an unused room ventilation combined operating mode, In the normal operation mode, the total supply air volume is adjusted according to the utilization rate of the room, while maintaining a constant air volume to each of the rooms being used; In the unused room ventilation combined operation mode, the air supply fan is inverter-controlled and the air volume control device is controlled based on the total air volume contained in unused rooms, which is the total air volume of the used rooms plus the air volume supplied to a predetermined number of unused rooms, thereby maintaining a constant air volume to each of the rooms in use, and opening the unopened air volume control devices corresponding to a predetermined number of unused rooms to ventilate the unused rooms.This is an air conditioning system as described in claim 1 or 2.

4. The air conditioning system of claim 3, wherein in the unused room ventilation combined operation mode, the air conditioning control device switches the unused air volume control devices that are opened corresponding to a predetermined number of unused rooms in a predetermined order each time a predetermined time has elapsed since the opening of an unused air volume control device, thereby ventilating the unused rooms sequentially.

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