HEAT SOURCE SYSTEM, CONTROL METHOD THEREFOR, AND PROGRAM

Abstract

 A heat source system (3) supplies a heat medium to an AHU (2). The heat source system (3) comprises: a plurality of heat source units; and a system controller that controls, in accordance with a requested-capacity requested by the AHU, the number of the plurality of heat source units to run. If it is necessary to start a plurality of the heat source units in order to meet the requested-capacity requested by the AHU (2), the system controller causes the heat source units to start in stages, until the number of heat source units that were started reaches a necessary number of units determined on the basis of the requested capacity.

Description

Technical Field

[0001] The present disclosure relates to a heat source system, a control method therefor, and a program.

Background Art

[0002] An air conditioning system is known, which includes a heat source system having a plurality of heat source machines and a use-side unit that performs air conditioning by using a heat medium supplied from the heat source system (for example, refer to PTL 1). In such an air conditioning system, the number control is performed to control the number of heat source machines in operation according to a required capacity required by the use-side unit.

[0003] In the number control of the related art, for example, in a case where a required capacity exceeding the rated capacity of one heat source machine is input at the time of activation of the use-side unit or the like, the heat source machine of the number required to satisfy the required capacity is activated at the same time, and the output command of each heat source machine is controlled to be increased at the upper limit rate to satisfy the required capacity in a short time as much as possible.

Citation List

Patent Literature

[0004] [PTL 1] Japanese Unexamined Patent Application Publication No. 2021-116948

Summary of Invention

Technical Problem

[0005] In the above-described control method of the related art, the output of the heat source system is rapidly changed. However, since the heat capacity of the use-side unit is relatively large, the use-side unit cannot quickly respond to the output of the heat source system and a response delay occurs. For this reason, in a case where the feedback control is performed in the use-side unit, hunting in which the increase and decrease of the required capacity are repeated occurs in a region where the output of the heat source system reaches near the required capacity. As a result, it took time for the output of the heat source system to be stabilized.

[0006] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a heat source system, a control method therefor, and a program capable of suppressing hunting of a required capacity.

Solution to Problem

[0007] A heat source system of the present disclosure is a heat source system that supplies a heat medium to a use-side unit, the heat source system includes a plurality of heat source machines; a system controller that controls the number of the plurality of heat source machines in operation according to a required capacity required by the use-side unit,
in which the system controller gradually activates the heat source machines until the number of activated heat source machines reaches a required number determined from the required capacity in a case where a plurality of the heat source machines need to be activated to satisfy the required capacity required by the use-side unit.

[0008] An air conditioning system of the present disclosure includes the heat source system; and an air handling unit to which a heat medium is supplied from the heat source system.

[0009] A control method for a heat source system of the present disclosure is a control method for a heat source system including a plurality of heat source machines and supplying a heat medium to a use-side unit, the method includes gradually activating the heat source machines until the number of activated heat source machines reaches a required number determined from a required capacity required by the use-side unit in a case where a plurality of the heat source machines need to be activated to satisfy the required capacity.

[0010] A program of the present disclosure is a program for causing a computer to function as the system controller. Advantageous Effects of Invention

[0011] It is possible to suppress the hunting of a required capacity.

Brief Description of Drawings

[0012] 

Fig. 1 is a diagram showing an overall schematic configuration of an air conditioning system according to an embodiment of the present disclosure.

Fig. 2 is a diagram showing a schematic configuration of a heat source system according to an embodiment of the present disclosure.

Fig. 3 is a diagram showing a configuration example of a refrigerant circuit of the heat source machine according to an embodiment of the present disclosure.

Fig. 4 is a diagram schematically showing an overall configuration of a control system for controlling the air conditioning system according to an embodiment of the present disclosure.

Fig. 5 is a diagram showing an example of a hardware configuration of a system controller according to an embodiment of the present disclosure.

Fig. 6 is a functional block diagram showing an example of a function included in a system controller according to an embodiment of the present disclosure.

Fig. 7 is a flowchart showing an example of a processing procedure of a method for controlling the heat source system executed by the system controller according to an embodiment of the present disclosure.

Fig. 8 is a flowchart showing an example of the processing procedure of the method for controlling the heat source system executed by the system controller according to an embodiment of the present disclosure.

Fig. 9 is a diagram showing an example of an activation timing and a capacity command of each heat source machine when the control of the heat source system according to an embodiment of the present disclosure is performed.

Fig. 10 is a diagram showing an example of the activation timing and the capacity command of each heat source machine when the control of the heat source system of a second mode according to a modification example of the present disclosure is performed.

Description of Embodiments

[0013] Hereinafter, an embodiment of a heat source system, a control method therefor, and a program according to the present disclosure will be described with reference to the drawings.

[0014] Fig. 1 is a diagram showing an overall schematic configuration of an air conditioning system according to an embodiment of the present disclosure. As shown in Fig. 1, an air conditioning system 1 includes a direct expansion type air handling unit (hereinafter, referred to as an "AHU") 2 and a heat source system 3. In the present embodiment, the AHU 2 is described as an example of the use-side unit, but the present disclosure is not limited thereto. The use-side unit may be another type of air handling unit such as a cold/hot water type air handling unit. In addition, the use-side unit is not limited to the air handling unit, and may be a system that performs air conditioning using a heat medium supplied from the heat source system.

[0015] The AHU 2 performs air conditioning and ventilation of a space to be air-conditioned (for example, a room R in Fig. 1) in various buildings such as an office, a commercial building, a hospital, and a factory. As shown in Fig. 1, the AHU 2 includes, for example, a total heat exchanger 21, a heat exchanger 22, a fan 23, a noise reduction 24, a fan 27, and an AHU controller 30. The total heat exchanger 21, the heat exchanger 22, the fan 23, the noise reduction 24, and the fan 27 are disposed in the housing 7, for example.

[0016] The total heat exchanger 21 exchanges heat between the air taken in from the outside and the air taken in from the room R. The air heat exchanged with the air from the room R in the total heat exchanger 21 is sent to the heat exchanger 22. The heat exchanger 22 exchanges heat between the air and the heat medium (the refrigerant in the present embodiment) supplied from the heat source system 3. The air cooled or heated by exchanging heat with the heat medium is sucked into the fan 23. The fan 23 sends out the sucked air. The air sent out from the fan 23 is sent to the room R which is a space to be air-conditioned through an air supply port 25 after passing through the noise reduction 24.

[0017] The air in the room R is sucked into the fan 27 through the ventilation port 26. The fan 27 discharges the air in the room R taken in from the ventilation port 26 to the total heat exchanger 21.

[0018] A temperature sensor 28 is provided on the downstream side of the air flow of the heat exchanger 22. The installation position of the temperature sensor 28 is not limited to this example, and may be a position where the temperature of the air after heat exchange in the heat exchanger 22 can be measured.

[0019] The AHU controller 30 calculates a required capacity based on a difference between the set temperature set by the remote controller 29 and the temperature measured by the temperature sensor 28, and outputs the required capacity to the heat source system 3. For example, the AHU controller 30 calculates the required capacity by performing feedback control based on the difference between the set temperature and the measured temperature. The calculation of the required capacity is known, and various known techniques may be appropriately adopted.

[0020]  In addition, the AHU controller 30 controls the rotation speeds of the fans 23 and 27. The control by the AHU controller 30 may adopt a known technique, and a detailed description thereof will be omitted.

[0021] The heat source system 3 includes a plurality of heat source machines 5 (refer to Fig. 2), and supplies the heat medium to the AHU 2.

[0022] Fig. 2 is a diagram showing a schematic configuration of the heat source system 3. As shown in Fig. 2, the heat source system 3 includes a plurality of heat source machines (outdoor units) 5a, 5b, and 5c. For example, the heat exchanger 22 included in the AHU 2 has a configuration in which a plurality of heat exchangers 22a, 22b, and 22c are integrated. In the present embodiment, the heat source machine 5a is configured to individually supply the heat medium to the heat exchanger 22a, the heat source machine 5b is configured to individually supply the heat medium to the heat exchanger 22b, and the heat source machine 5c is configured to individually supply the heat medium to the heat exchanger 22c. The correspondence relationship between the heat source machine 5 and the heat exchanger 22 is not limited to this example, and a known refrigerant connection form can be appropriately adopted.

[0023] In addition, in the following, when it is necessary to distinguish the heat source machines 5a and 5b from each other, the heat source machines 5a and 5b are referred to as the heat source machines 5a and 5b, and when it is not necessary to distinguish the heat source machines 5a and 5b, the heat source machines 5a and 5b are simply referred to as the heat source machine 5. In addition, the same applies to other configurations.

[0024] Fig. 3 is a diagram showing a configuration example of a refrigerant circuit of the heat source machine 5a. The refrigerant circuit of the heat source machine 5b and the refrigerant circuit of the heat source machine 5c also have the same configuration.

[0025] As shown in Fig. 3, the heat source machine 5a is a heat source machine of a heat pump type, and includes a compressor 11 that compresses the refrigerant. The compressor 11 is, for example, a compressor having a variable rotation speed driven by an inverter motor (not shown). For example, the output of the heat source machine 5a is controlled by controlling the frequency (rotation speed) of the inverter motor of the compressor 11 by the heat source machine controller 8a (to be described later). The compressor 11 is not limited to this example, and may be, for example, a fixed speed compressor in which the rotation speed is fixed.

[0026] In addition, the heat source machine 5a includes the heat exchanger 13 that exchanges heat between the refrigerant and the outside air, the fan 14, an electron expansion valve 16 that expands the refrigerant, and the like. In addition, the heat source machine 5a may include a switching valve (for example, a four-way switching valve) 12 that switches a circulation direction of the refrigerant. By providing the switching valve 12, it is possible to correspond to both the cooling and the heating. In addition, the heat source machine 5a may include an accumulator 15 provided in a suction-side pipe of the compressor 11 for the purpose of gas-liquid separation of the refrigerant.

[0027] The heat exchanger 22a included in the AHU 2 shares the heat source machine 5a and a refrigerant pipe, and is configured to directly supply the refrigerant from the heat source machine 5a.

[0028] As an example of the refrigerant circulating through the refrigerant pipe, a low global-warming potential (GWP) mildly flammable refrigerant can be given. For example, the general alternative refrigerant in the HFC refrigerant regulation for preventing global warming (for example, R1234yf [4], R1234ze(E) [4], R1233zd(E) [5], R32 [675], and the like, the numerals in the square brackets [ ] indicate the GWP (100-year value)) and the refrigerant having the same or equivalent GWP (100-year value) are given. The type of the refrigerant is not particularly limited, and other refrigerants such as a brine, or water may be used.

[0029] Since the operation of the heat source machine of the heat pump type is known, a detailed description thereof will be omitted.

[0030] Fig. 4 is a diagram schematically showing an overall configuration of a control system that controls the air conditioning system according to the present embodiment. As shown in Fig. 4, the air conditioning system 1 includes an AHU controller 30, a system controller 10, and a heat source machine controller 8 (8a, 8b, and 8c).

[0031] The AHU controller 30, the system controller 10, and the heat source machine controller 8 (8a, 8b, and 8c) are connected to each other via a communication line and are configured to be capable of bidirectional communication.

[0032]  The system controller 10 controls the heat source system 3. For example, the system controller 10 performs the number control for controlling the number of the plurality of heat source machines 5 in operation according to the required capacity required by the AHU 2.

[0033] In addition, the system controller 10 may perform capacity allocation control for allocating a capacity to the heat source machine 5. The system controller 10 transmits, for example, an activation or deactivation command and a capacity command to each of the heat source machine controllers 8a to 8c.

[0034] The heat source machine controller 8 controls the driving of the compressor 11 (refer to Fig. 3) and the like based on an activation command and a deactivation command received from the system controller 10. In addition, the rotation speed of the compressor 11 is controlled based on the capacity command. For example, the heat source machine controller 8 has an arithmetic expression or a table for converting the capacity command into a frequency command of the compressor 11, and controls the rotation speed of the compressor 11 corresponding to the capacity command by using these pieces of information. Since various control methods for the capacity control (output control) of the compressor have been proposed, it is possible to appropriately adopt the known method.

[0035] Fig. 5 is a diagram showing an example of a hardware configuration of the system controller 10. As shown in Fig. 5, the system controller 10 includes, for example, a central processing unit (CPU) (processor) 31, a main memory 32, a secondary storage (memory) 33, and a communication interface 34. The respective units are directly or indirectly connected to each other via a bus, and cooperate with each other to execute various processing.

[0036] The CPU 31 performs control of the entire heat source system by an operating system (OS) stored in the secondary storage 33 connected via a bus, for example, and performs various processing by executing various programs stored in the secondary storage 33. One or a plurality of the CPUs 31 may be provided to cooperate with each other to realize the processing.

[0037] For example, the main memory 32 includes a writable memory such as a cache memory or a random-access memory (RAM), and is used as a work region for reading an execution program of the CPU 31 and writing processing data of the execution program.

[0038] The secondary storage 33 is a non-transitory computer readable storage medium. The secondary storage 33 is, for example, a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Examples of the secondary storage 33 include a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), and a flash memory. The secondary storage 33 stores, for example, an OS for controlling the entire heat source system such as Windows (registered trademark), iOS (registered trademark), and Android (registered trademark), a basic input/output system (BIOS), various device drivers for operating the hardware of the peripheral devices, various application software, various data and files, and the like. In addition, the secondary storage 33 stores a program for realizing various processing and various data required to realize various processing. A plurality of the secondary storages 33 may be provided, and the program and the data as described above may be divided and stored in each of the secondary storages 33. In addition, the secondary storage 33 may be provided on a cloud, and some of the programs or data stored in the secondary storage 33 may be provided on a cloud.

[0039]  The communication interface 34 functions as an interface for performing communication with another device via a communication line and transmitting and receiving information. For example, the communication interface 34 communicates with the other devices in a wired or wireless manner. Examples of the wireless communication include communication through a line such as Bluetooth (registered trademark), Wi-Fi, a mobile communication system (3G, 4G, 5G, 6G, LTE, or the like), and a wireless LAN. Examples of the wired communication include communication through a line such as a wired local area network (LAN).

[0040] The AHU controller 30 and the heat source machine controller 8 are also computers and have the same configuration as the system controller 10 described above.

[0041] Fig. 6 is a functional block diagram showing an example of a function included in the system controller 10. As shown in Fig. 6, the system controller 10 includes a storage unit 41, a number-of-machines control unit 42, and a capacity allocation unit 43.

[0042] The storage unit 41 stores operation priority information (for example, an operation priority table) in which an operation priority for each of the heat source machines 5a, 5b, and 5c is set, rated capacity information (for example, a rated capacity table) in which a rated capacity for each of the heat source machines 5a, 5b, and 5c is set, and activation threshold values for activating each of the heat source machines and deactivation threshold values for deactivating each of the heat source machines.

[0043] Further, the storage unit 41 stores a rate (change rate) for increasing or decreasing the target capacity to be described later.

[0044] In the present embodiment, as an example, the priority is set in the order of the heat source machines 5a, 5b, and 5c, and the activation threshold value for activating the heat source machine 5b, the activation threshold value for activating the heat source machine 5c, the deactivation threshold value for deactivating the heat source machine 5c, and the deactivation threshold value for deactivating the heat source machine 5b are set. Each activation threshold value and each deactivation threshold value are appropriately set in consideration of the rated capacity and the activation priority of each heat source machine 5.

[0045] Here, the operation priority set as the operation priority information may be changed at a predetermined time interval. Accordingly, it is possible to reduce a deviation in the cumulative operation time of each heat source machine.

[0046] The number-of-machines control unit 42 controls the number of the heat source machines 5. For example, in a case where the plurality of heat source machines 5 need to be activated to satisfy the required capacity required by the AHU 2, the number-of-machines control unit 42 gradually activates the heat source machines 5 until the number of activated heat source machines 5 reaches a required number determined from the required capacity.

[0047] The number-of-machines control unit 42 increases the target capacity for controlling the heat source system 3 from zero to the required capacity at a predetermined rate, for example, at the time of activating the heat source system 3, and activates the heat source machine 5 based on the target capacity.

[0048] In addition, in a case where the required capacity is changed during the operation of the heat source system 3, the number-of-machines control unit 42 increases or decreases the target capacity to the changed required capacity at a predetermined rate, and controls the activation or deactivation of the heat source machine 5 based on the target capacity.

[0049] Here, the predetermined rate may be a fixed value or may be a value that is dynamically changed. In addition, the predetermined rate may be set for each heat source machine, for example, according to the rated capacity of each heat source machine.

[0050] The capacity allocation unit 43 refers to the rated capacity information stored in the storage unit 41 to allocate the capacity such that the capacity does not exceed the rated capacity of each heat source machine 5. Since various methods for allocating the capacities have been proposed, a known technique may be adopted. Examples of the allocation method include, in a case where the plurality of the heat source machine 5 are operated, a method for changing a capacity command of one heat source machine 5 among the plurality of heat source machines 5 according to a change in the required capacity and operating the remaining heat source machines 5 at a rated capacity, a method for evenly allocating the capacities to the plurality of heat source machines 5, and a method for setting information on an optimal capacity rate range in which a coefficient of performance (COP) of each heat source machine 5 is equal to or higher than a predetermined value in advance for each heat source machine 5 and allocating the capacities such that a capacity rate of each heat source machine 5 is within the optimal capacity rate range, respectively.

[0051] Next, a control method of the heat source system 3 executed by the system controller 10 will be described with reference to Figs. 7 and 8. Figs. 7 and 8 are flowcharts showing an example of a processing procedure of the control method of the heat source system 3 executed by the system controller 10. The system controller 10 starts the process shown below when, for example, an activation command is received from the AHU controller 30, and ends the process after a deactivation command is transmitted to the heat source machine 5 in operation when a deactivation command is received from the AHU controller 30.

[0052] First, the system controller 10 sets the target capacity to zero at the time of activating the system (SA1 in Fig. 7), and then increases the target capacity by a predetermined amount according to a predetermined rate (SA2). Next, the system controller 10 specifies the heat source machine 5 to be activated by using the priority information of the storage unit 41, and outputs an activation command and a capacity command determined from the target capacity to the heat source machine controller 8 of the specified heat source machine 5 (SA3).

[0053] Next, the system controller 10 determines whether or not the current target capacity and the required capacity match each other (SA4) . As a result, in a case where the target capacity and the required capacity match (SA4: YES), the operation of the current heat source machine 5 is maintained until the required capacity is changed.

[0054] Meanwhile, in a case where the target capacity and the required capacity do not match each other (SA4: NO), it is determined whether or not the target capacity is less than the required capacity (SA5). As a result, in a case where the target capacity is less than the required capacity, the target capacity is required to be increased to approach the required capacity (SA5: YES). Therefore, the system controller 10 increases the target capacity by a predetermined amount according to the predetermined rate (SA6). Then, the target capacity is determined whether or not it is equal to or higher than the activation threshold value (SA7). As a result, in a case where the target capacity is less than the activation threshold value (SA7: NO), the target capacity can be covered by the heat source machine 5 in operation. Therefore, the target capacity is allocated to the heat source machine 5 in operation, and the capacity command on the basis of the allocation is output to each heat source machine in operation (SA8), and the process returns to step SA4.

[0055] On the other hand, in a case where the target capacity is equal to or more than the activation threshold value (SA7: YES), the target capacity cannot be covered by the heat source machine 5 in operation, and thus the heat source machine 5 that is deactivated needs to be newly activated. In this case, the system controller 10 specifies the heat source machine 5 to be activated by using the priority information stored in the storage unit 41. Further, the system controller 10 performs capacity allocation to the heat source machine 5 to be activated and the heat source machine 5 in operation (SA9).

[0056] Then, the system controller 10 transmits the capacity command to the heat source machine 5 in operation, and transmits the activation command and the capacity command to the heat source machine 5 to be newly activated (SA10), and the process returns to step SA4.

[0057] On the other hand, in step SA5, in a case where the target capacity is larger than the required capacity (SA5: NO), the target capacity is required to be reduced to approach the required capacity. Therefore, the system controller 10 reduces the target capacity by a predetermined amount according to a predetermined rate (SA11 in Fig. 8). Subsequently, it is determined whether or not the target capacity is less than the deactivation threshold value (SA12). As a result, in a case where the target capacity is equal to or more than the deactivation threshold value (SA12: NO), when the heat source machine 5 is deactivated, the target capacity cannot be covered. For this reason, the system controller 10 allocates the target capacity to the heat source machine 5 in operation without deactivating the heat source machine 5, and outputs the capacity command on the basis of the allocation to each heat source machine 5 in operation (SA13), and the process returns to step SA4 in Fig. 7.

[0058] On the other hand, in step SA12, in a case where the target capacity is less than the deactivation threshold value (SA12: YES), it is necessary to deactivate the heat source machine in operation. In this case, the system controller 10 specifies the heat source machine 5 to be deactivated by using the priority information stored in the storage unit 41. Further, the system controller 10 performs the capacity allocation on the heat source machine 5 in operation except for the heat source machine 5 to be deactivated (SA14).

[0059] Then, the system controller 10 transmits a deactivation command to the heat source machine 5 to be deactivated, and transmits a capacity command to the other heat source machine 5 in operation except for the heat source machine 5 to be deactivated (SA15), and the process returns to step SA4.

[0060] Then, the system controller 10 continuously performs the above-described process until the deactivation command is received from the AHU controller 30.

[0061] Fig. 9 is a diagram showing an example of the activation timing and the capacity command of each heat source machine 5 when the control of the heat source system 3 described above is performed. As shown in Fig. 9, in a case where the required capacity Cd exceeding the rated capacity of one heat source machine 5 is input from the AHU controller 30 at the time of activating the heat source system 3, one heat source machine 5a is activated at time T1, and the target capacity is increased from zero at a predetermined rate. Accordingly, the output of the heat source machine 5a increases in accordance with the target capacity.

[0062] Then, when the target capacity is equal to or more than the activation threshold value of the heat source machine 5b at time T2, the second heat source machine 5b is activated, and the target capacity is allocated to the heat source machines 5a and 5b in operation. Then, each of the heat source machines 5a and 5b is controlled by the heat source machine controllers 8a and 8b based on the allocated target capacity. Accordingly, the output of the heat source machine 5a is temporarily lowered when the heat source machine 5b is activated, and then is increased, and thereafter, the output is stabilized at the rated output. On the other hand, the heat source machine 5b is allocated with a capacity obtained by subtracting the capacity of the heat source machine 5a from the target capacity. In this manner, the output of the heat source machine 5b increases at the same rate as the target capacity.

[0063] Then, when the target capacity is equal to or more than the activation threshold value of the heat source machine 5c at time T3, the third heat source machine 5c is activated, and the target capacity is allocated to the heat source machines 5a, 5b and 5c in operation. Then, each of the heat source machines 5a, 5b, and 5c is controlled by the heat source machine controllers 8a, 8b, and 8c based on the allocated target capacity. Accordingly, the output of the heat source machines 5a and 5b is temporarily lowered when the heat source machine 5c is activated, and then is increased, and thereafter, the output is stabilized at the rated output. On the other hand, the heat source machine 5c is allocated with a capacity obtained by subtracting the sum of the rated capacities of the heat source machines 5a and 5b from the target capacity. In this manner, the output of the heat source machine 5c increases at the same rate as the target capacity.

[0064] Then, when the target capacity matches with the required capacity Cd at time T4, the target capacity is constant until the required capacity is changed, and the stable operation of the heat source system 3 can be realized. In addition, since the capacity of the heat source system 3 gradually increases in this manner, the refrigerant for satisfying the required capacity is sent to the heat exchanger 22 (refer to Fig. 1) and cooling or heating is achieved by the refrigerant exchanging heat with the air. As a result, the air in the room R is gradually cooled or heated and is gradually adjusted to a desired temperature.

[0065] As described above, according to the heat source system, the control method therefor, and the program in the present embodiment, in a case where the plurality of heat source machines 5 need to be activated to satisfy the required capacity required by the AHU 2, the system controller does not simultaneously activate the number of heat source machines 5 required to satisfy the required capacity, but gradually activates the heat source machines 5 until the required capacity is satisfied.

[0066] Accordingly, the hunting of the required load can be reduced as compared to a case where the required number of heat source machines is simultaneously activated to satisfy the required capacity, and thus it is possible to realize more stable operation of the heat source system.

[0067] The present disclosure has been described above with reference to the embodiments, but the technical scope of the present disclosure is not limited to the above-described embodiments. Various modifications or improvements can be added to the above-described embodiments within the scope not departing from the concept of the present disclosure, and forms to which the modifications or the improvements are added are also included in the technical scope of the present disclosure. Further, the above embodiment may be appropriately combined.

[0068] In addition, the flow of the process described in the above embodiment is also an example, and unnecessary steps may be deleted, new steps may be added, or the procedure may be changed without departing from the gist of the present invention.

[0069] For example, in the above-described embodiment, the outdoor unit has been described as an example of the heat source machine 5. However, the present disclosure is not limited to this example. For example, the heat source machine 5 may be a centrifugal chiller or the like, and may be a machine that supplies a temperature-controlled heat medium to the use-side unit.

[0070] In addition, in the above-described embodiment, the system controller 10 performs the number control and the capacity allocation of the heat source machine 5 by using the target capacity. However, the present disclosure is not limited to this example. For example, the number control and the capacity allocation of the heat source machine 5 may be performed directly using the required capacity without using the target capacity.

[0071] In addition, in the above-described embodiment, the predetermined rate (change rate) for increasing or decreasing the target capacity is set to be constant. However, the present disclosure is not limited to this example, and the predetermined rate may be dynamically set according to the operating state. For example, the predetermined rate may be dynamically set according to a difference between the target capacity and the required capacity, a difference between the output capacity and the required capacity of the heat source system 3, or the like. For example, in a case where the difference between the target capacity and the required capacity is larger than a predetermined first threshold value, by setting the rate to a value larger than the prescribed value (default value), it is possible to shorten the time until the target capacity reaches the required capacity. In addition, in a case where the difference between the target capacity and the required capacity is less than a predetermined second threshold value, by reducing the rate below the prescribed value, it is possible to moderate the increase in the output of the heat source system 3. Accordingly, it is possible to further reduce the hunting. In addition, the first threshold value and the second threshold value may be different values or may be the same value. In addition, the number of the threshold values is not limited to two, and three or more threshold values may be provided, and the rate may be adjusted in a stepwise manner.

[0072] In addition, the system controller 10 may calculate the number of heat source machines 5 required to satisfy the required capacity from the rated capacity of each of the heat source machines 5 at the time of activation, and may gradually activate the calculated number of heat source machines 5. In this case, the next heat source machine 5 may be activated after a predetermined period of time has elapsed from the activation of the first heat source machine 5. In addition, an interval may be set, for example, according to the rated capacity of the heat source machine 5, after a predetermined period of time has elapsed. For example, in a case where the capacity command is given to the heat source machine 5 at a predetermined rate, it is possible to estimate in advance a time required for the heat source machine 5 to reach the rated capacity. Therefore, an interval for activating the heat source machine 5 may be set according to the estimated time.

[0073] In addition, in the above-described embodiment, the system controller 10 activates the heat source machine 5 one by one. However, the present disclosure is not limited to this example. For example, when three or more heat source machines 5 need to be activated to satisfy the required capacity at the time of activation of the heat source system 3, the system controller 10 may simultaneously activate a plurality of heat source machines (for example, the heat source machines 5a and 5b) at the time of activating the heat source system 3, and then activate a smaller number of heat source machines (for example, the heat source machine 5c) than the number of heat source machines activated at the time of activating the heat source system.

[0074] In the heat source system 3 of the present disclosure, the system controller 10 may include a first mode and a second mode. Here, the first mode is a mode that gradually activates the heat source machine 5 until the number of the activated heat source machines 5 reaches a required number determined from the required capacity in a case where the plurality of heat source machines 5 need to be activated to satisfy the required capacity. As an example of the first mode, the control method according to the above-described embodiment is given.

[0075]  In addition, the second mode is a mode that simultaneously activates the required number of the heat source machine 5 in a case where the plurality of heat source machines 5 need to be activated to satisfy the required capacity. For example, as shown in Fig. 10, the second mode is a mode that simultaneously activates the heat source machines 5a, 5b, and 5c in a case where the required capacity equivalent to the rated capacity of three heat source machines 5 is received.

[0076] The first mode and the second mode may be configured to be switchable. For example, the remote controller 29 (refer to Fig. 1) may be provided with an input unit for mode switching.

[0077] According to the first mode, as shown in Fig. 9, the output capacity of the heat source system 3 requires a long period of time to reach the required capacity as compared with the second mode. Meanwhile, hunting can be suppressed, and the operation at the time of activation can be made more stable. In addition, according to the second mode, as shown in Fig. 10, there is a possibility that hunting may occur. Meanwhile, there is an advantage in that the output of the heat source system 3 can be increased in a short period of time as compared to the first mode.

[0078] The user can select a desired mode in consideration of such merits and demerits.

[0079] In addition, in the present embodiment, the AHU controller 30 is provided, and the required capacity is input to the system controller 10 from the AHU controller 30. However, the present invention is not limited to this aspect. For example, the AHU controller 30 can be omitted. In this case, setting temperature information of the remote controller 29 and a detection value of the temperature sensor 28 are input to the system controller 10. The system controller 10 may calculate the required capacity from these pieces of information.

[0080] The heat source system, the control method therefor, and the program described in the above-described embodiment are grasped as follows, for example.

[0081] A heat source system (3) of the present disclosure is a heat source system (3) that supplies a heat medium to a use-side unit (2), the heat source system (3) includes a plurality of heat source machines (5); a system controller (10) that controls the number of the plurality of heat source machines in operation according to a required capacity required by the use-side unit, in which the system controller gradually activates the heat source machines until the number of activated heat source machines reaches a required number determined from the required capacity in a case where a plurality of the heat source machines need to be activated to satisfy the required capacity required by the use-side unit.

[0082] According to the heat source system of the present disclosure, the hunting of the required load can be reduced as compared to a case where the required number of heat source machines is simultaneously activated to satisfy the required capacity, and thus it is possible to realize more stable operation of the heat source system.

[0083] In the heat source system of the present disclosure, the system controller may increase a target capacity for controlling the heat source system from zero to the required capacity at a predetermined rate at the time of activating the heat source system, and may activate the heat source machine based on the target capacity.

[0084] According to the present aspect, the heat source machine can be gradually activated by simple process.

[0085] In the heat source system of the present disclosure, the system controller may increase or decrease the target capacity to the required capacity at a predetermined rate in a case where the required capacity is changed during an operation of the heat source system, and may control the activation or deactivation of the heat source machine based on the target capacity.

[0086] According to the present aspect, it is possible to control the number of the heat source machine by simple process.

[0087] In the heat source system of the present disclosure, the predetermined rate may be settable for each of the heat source machines according to a rated capacity of the heat source machine.

[0088] According to the present aspect, it is possible to set an appropriate rate in consideration of the rated capacity (maximum capacity of the compressor) of the heat source machine. The predetermined rate may be set to a value smaller than the rated capacity of the heat source machine.

[0089] In the heat source system of the present disclosure, the predetermined rate may be dynamically settable according to a difference between the target capacity and the required capacity.

[0090] Accordingly, for example, in a case where a difference between the target capacity and the required capacity is large, a time required for the target capacity to reach the required capacity can be shortened by increasing the rate. In addition, in a case where the difference between the target capacity and the required capacity is small, hunting can be effectively suppressed by reducing the rate to alleviate the output change of the heat source system.

[0091] In the heat source system of the present disclosure, in a case where the plurality of heat source machines need to be activated to satisfy the required capacity, the system controller may sequentially activate the heat source machines at a predetermined time interval.

[0092] According to the present aspect, it is possible to control the number of the heat source machine by simple process.

[0093] In the heat source system of the present disclosure, in a case where three or more heat source machines need to be activated to satisfy the required capacity at the time of activating the heat source system, the system controller may activate a plurality of the heat source machines at the time of activating the heat source system, and thereafter, may activate a smaller number of the heat source machines than at the time of activating the heat source system.

[0094] In the heat source system of the present disclosure, the system controller includes a first mode and a second mode, the first mode may be a mode that gradually activates the heat source machines until the number of activated heat source machines reaches the required number determined from the required capacity in a case where the plurality of heat source machines need to be activated to satisfy the required capacity, and the second mode may be a mode that simultaneously activates the required number of the heat source machines in a case where the plurality of heat source machines need to be activated to satisfy the required capacity, and the first mode and the second mode may be switchable.

[0095] According to the present aspect, it is possible to switch the mode according to the user's request or the like.

[0096] In the heat source system of the present disclosure, the system controller may receive the required capacity from a unit-side controller (30) that controls the use-side unit.

[0097] An air conditioning system (1) of the present disclosure includes the heat source system (3) of the present disclosure; and an air handling unit (2) to which a heat medium is supplied from the heat source system.

[0098] A control method for a heat source system of the present disclosure is a control method for a heat source system (3) including a plurality of heat source machines (5) and supplying a heat medium to a use-side unit (2), the method includes gradually activating the heat source machines until the number of activated heat source machines reaches a required number determined from a required capacity required by the user-side unit in a case where a plurality of the heat source machines need to be activated to satisfy the required capacity.

[0099] A program of the present disclosure is a program for causing a computer to function as the system controller. Reference Signs List

[0100] 

1:

Air conditioning system

2:

AHU (direct expansion type air handling unit) (use-side unit)

3:

Heat source system

5:

Heat source machine

5a:

Heat source machine

5b:

Heat source machine

5c:

Heat source machine

7:

Housing

8:

Heat source machine controller

8a:

Heat source machine controller

8b:

Heat source machine controller

8c:

Heat source machine controller

10:

System controller

11:

Compressor

12:

Switching valve

13:

Heat exchanger

14:

Fan

15:

Accumulator

16:

Electron expansion valve

21:

Total heat exchanger

22:

Heat exchanger

22a:

Heat exchanger

22b:

Heat exchanger

22c:

Heat exchanger

23:

Fan

24:

Noise reduction

25:

Air supply port

26:

Ventilation port

27:

Fan

28:

Temperature sensor

29:

Remote controller

30:

AHU controller

31:

CPU

32:

Main memory

33:

Secondary storage

34:

Communication interface

41:

Storage unit

42:

Number-of-machines control unit

43:

Capacity allocation unit

Claims

1. A heat source system that supplies a heat medium to a use-side unit, the heat source system comprising:

a plurality of heat source machines; and

a system controller that controls the number of the plurality of heat source machines in operation according to a required capacity required by the use-side unit,

wherein the system controller gradually activates the heat source machines until the number of activated heat source machines reaches a required number determined from the required capacity in a case where a plurality of the heat source machines need to be activated to satisfy the required capacity required by the use-side unit.

2. The heat source system according to claim 1,
wherein the system controller

increases a target capacity for controlling the heat source system from zero to the required capacity at a predetermined rate at the time of activating the heat source system, and

activates the heat source machines based on the target capacity.

3. The heat source system according to claim 2,
wherein the system controller

increases or decreases the target capacity to the required capacity at a predetermined rate in a case where the required capacity is changed during an operation of the heat source system, and

controls the activation or deactivation of the heat source machines based on the target capacity.

4. The heat source system according to claim 2 or 3,
wherein the predetermined rate is settable for each of the heat source machines according to a rated capacity of the heat source machines.

5. The heat source system according to any one of claims 2 to 4,
wherein the predetermined rate is dynamically settable according to a difference between the target capacity and the required capacity.

6. The heat source system according to claim 1,
wherein in a case where the plurality of heat source machines need to be activated to satisfy the required capacity, the system controller sequentially activates the heat source machines at a predetermined time interval.

7. The heat source system according to claim 1,
wherein in a case where three or more heat source machines need to be activated to satisfy the required capacity at the time of activating the heat source system, the system controller activates a plurality of the heat source machines at the time of activating the heat source system, and thereafter, activates a smaller number of the heat source machines than at the time of activating the heat source system.

8. The heat source system according to claim 1,

wherein the system controller includes a first mode and a second mode,

the first mode is a mode that gradually activates the heat source machines until the number of activated heat source machines reaches the required number determined from the required capacity in a case where the plurality of heat source machines need to be activated to satisfy the required capacity, and

the second mode is a mode that simultaneously activates the required number of the heat source machines in a case where the plurality of heat source machines need to be activated to satisfy the required capacity, and

the first mode and the second mode are switchable.

9. The heat source system according to any one of claims 1 to 8,
wherein the system controller receives the required capacity from a unit-side controller that controls the use-side unit.

10. An air conditioning system comprising:

the heat source system according to any one of claims 1 to 9; and

an air handling unit to which a heat medium is supplied from the heat source system.

11. A control method for a heat source system including a plurality of heat source machines and supplying a heat medium to a use-side unit, the method comprising:
gradually activating the heat source machines until the number of activated heat source machines reaches a required number determined from a required capacity required by the use-side unit in a case where a plurality of the heat source machines need to be activated to satisfy the required capacity.

12. A program for causing a computer to function as the system controller according to any one of claims 1 to 9.

Drawing