Heat source system, air conditioning system, control method, and control program

Abstract

A heat source system (3) supplies a heat medium to a user-side unit (2) and comprises: a plurality of heat source devices (5); and a controller (8) that controls the number of operating heat source devices and the operation capacity of the plurality of heat source devices (5) in accordance with a capacity required at the user-side unit (2), wherein the controller (8) collects information pertaining to defrost control of the heat source devices (5) and performs control to assign, to another heat source device (5), an operation capacity which is required of at least one heat source device (5) that performs the defrost control.

Description

Technical Field

[0006] , , ,

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

Background Art

[0002] Conventionally, an air conditioning system including a heat source system having a plurality of heat source machines and a user-side unit that performs air conditioning using a heat medium supplied from the heat source system is known. In such an air conditioning system, when a heat source machine enters defrost control, the corresponding heat source machine enters a cooling cycle, so the capacity of the air conditioning system decreases.

[0003] On the other hand, Patent Document 1 discloses that in a heat pump system, when any module enters defrost operation, other modules are regarded as being in a state where they are likely to enter defrost, and a margin rate is multiplied to avoid applying a heat load in order to avoid entering defrost operation.

[0004] Further, Patent Document 2 discloses that information indicating that defrost operation is being performed in one outdoor unit is transmitted to other outdoor units, and when information indicating that defrost operation is being performed in one outdoor unit is received while heating operation is being performed in another outdoor unit, the defrost operation is not performed and the heating operation is continued.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the inventions described in Patent Documents 1 and 2 did not consider how the operating capacity of the heat source unit performing defrost control decreases due to defrost control, thereby reducing the overall capacity of the air conditioning system.

[0007] This disclosure is made in view of these circumstances and aims to provide a heat source system, an air conditioning system, a control method, and a control program that prevent performance degradation when defrost control is performed. [Means for solving the problem]

[0008] To solve the above problems, the heat source system, air conditioning system, control method, and control program of this disclosure employ the following means.

[0009] The heat source system of this disclosure is a heat source system that supplies a heat transfer medium to a user-side unit, comprising a plurality of heat source machines and a controller that controls the number of operating machines and the operating capacity of the plurality of heat source machines according to the required capacity required by the user-side unit, wherein the controller collects information regarding the defrost control of the heat source machines and controls the allocation of the operating capacity required by one or more heat source machines that perform the defrost control to the other heat source machines. The heat source unit that performs the defrost control starts the defrost control after a predetermined time has elapsed since the defrost control conditions for determining the start of the defrost control were met, and the heat source unit that performs the defrost control operates at its minimum operating capacity during the defrost control. .

[0010] The air conditioning system of this disclosure comprises the aforementioned heat source system and an air handling unit to which a heat transfer medium is supplied from the heat source system.

[0011] The control method disclosed herein is a control method for a heat source system comprising a plurality of heat source units that supply a heat transfer medium to a user-side unit, comprising: collecting information on the defrost control of the heat source units; and assigning the operating capacity required by one or more heat source units that perform the defrost control to the other heat source units. The heat source unit that performs the defrost control starts the defrost control after a predetermined time has elapsed since the defrost control conditions for determining the start of the defrost control were met, and the heat source unit that performs the defrost control operates at its minimum operating capacity during the defrost control. The computer performs the control.

[0012] The control program disclosed herein causes a computer to function as the aforementioned controller. [Effects of the Invention]

[0013] According to the heat source system of this disclosure, it is possible to determine which heat source unit has entered defrost control. Based on this information, the operating capacity provided by the heat source unit that has entered defrost control can be distributed to the other heat source units, preventing the capacity from falling below the required capacity for the user unit and resolving capacity shortages. [Brief explanation of the drawing]

[0014] [Figure 1] This figure shows the overall schematic configuration of an air conditioning system according to one embodiment of the present disclosure. [Figure 2] This figure shows a schematic configuration of a heat source system according to one embodiment of the present disclosure. [Figure 3] This figure shows an example of the configuration of a refrigerant circuit in a heat source unit according to one embodiment of the present disclosure. [Figure 4] This figure schematically shows the overall configuration of a control system for controlling an air conditioning system according to one embodiment of the present disclosure. [Figure 5] This figure shows an example of the hardware configuration of a heat source controller according to one embodiment of the present disclosure. [Figure 6] This is a functional block diagram showing an example of the functions of a heat source controller according to one embodiment of this disclosure. [Figure 7] This flowchart shows an example of a processing procedure for a heat source system control method executed by a heat source controller according to one embodiment of the present disclosure. [Figure 8] This figure shows the capacity distribution of a heat source unit by a heat source unit controller according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0015] (Air conditioning system configuration) An embodiment of the heat source system, its control method, and program related to this disclosure will be described below with reference to the drawings. FIG. 1 is a diagram showing the overall schematic configuration of an air conditioning system according to an embodiment of the present disclosure. As shown in FIG. 1, the air conditioning system 1 includes a direct expansion air handling unit (hereinafter referred to as "AHU") 2 and a heat source system 3. In this embodiment, the AHU 2 is exemplified and described as the user-side unit 2, but it is not limited thereto. The user-side unit 2 may be another type of air handling unit such as a chilled water type air handling unit. Further, the user-side unit 2 is not limited to an air handling unit, and any system that performs air conditioning using a heat medium supplied from the heat source system 3 may be used.

[0016] The AHU 2 performs air conditioning and ventilation of an air-conditioned space (for example, the indoor space R in FIG. 1) in various buildings such as offices, commercial buildings, hospitals, and factories. As shown in FIG. 1, the AHU 2 includes, for example, a total heat exchanger (not shown), heat exchangers 21 (21a, 21b, 21c), temperature sensors 22 (22a, 22b, 22c), a fan 23, and a temperature sensor 24. The heat exchangers 21 (21a, 21b, 21c), the temperature sensors 22 (22a, 22b, 22c), the fan 23, and the temperature sensor 24 are arranged, for example, in a housing 7.

[0017] The total heat exchanger exchanges heat between the air taken in from the outside and the air taken in from the indoor space R. The air that has exchanged heat with the air from the indoor space R in the total heat exchanger is sent to the heat exchanger 21. The heat exchanger 21 exchanges heat between the air and a heat medium (in this embodiment, a refrigerant) supplied from the heat source system 3. The air cooled or heated by the heat exchange 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 indoor space R, which is the air-conditioned space, after passing through a pipe.

[0018] A temperature sensor 22 is provided in the heat exchanger 21. The installation position of the temperature sensor 22 is not limited to this example, and any position where the temperature of the air after heat exchange in the heat exchanger 21 can be detected may be used.

[0019] The system controller 10 (AHU controller) calculates the required capacity based on the difference between the set temperature set by the remote controller (not shown) and the temperature detected by the temperature sensor 24, and outputs it to the heat source system 3. For example, the system controller 10 calculates the required capacity by performing feedback control based on the difference between the set temperature and the detected temperature. The calculation of the required capacity is publicly known, and various publicly known techniques may be adopted as appropriate.

[0020] Furthermore, the system controller 10 controls the rotation speed of the fan 23. Note that the control performed by the system controller 10 can be based on known technologies, and a detailed explanation is omitted here.

[0021] The heat source system 3 is equipped with heat source controllers 8 (8a, 8b, 8c), with, for example, heat source controller (controller) 8a acting as the master unit. Heat source controller 8a controls the operating conditions and output capacity of each heat source unit 5 (5a, 5b, 5c) via each heat source controller 8. The heat source controller 8 may also control the operating conditions and output capacity of each heat source unit 5 based on the information input by the remote controller 29.

[0022] The heat source system 3 is equipped with multiple heat source units 5 (see Figure 2) and supplies a heat transfer medium to the AHU 2. Figure 2 is a diagram showing the schematic configuration of the heat source system 3. As shown in Figure 2, the heat source system 3 is equipped with multiple heat source units (outdoor units) 5a, 5b, and 5c. The heat exchanger 21 equipped in the AHU2 is configured such that multiple heat exchangers 21a, 21b, and 21c are integrated into one unit. In this embodiment, heat source unit 5a supplies a heat medium to heat exchanger 21a, heat source unit 5b supplies a heat medium to heat exchanger 21b, and heat source unit 5c supplies a heat medium to heat exchanger 21c individually. Note that the correspondence between the heat source units 5 and the heat exchangers 21 is not limited to this example, and known refrigerant connection configurations can be appropriately adopted.

[0023] Furthermore, in the following, when it is necessary to distinguish between heat source units 5a, 5b, etc., they will be referred to as heat source units 5a, 5b, etc., and when it is not necessary to distinguish between them, they will simply be referred to as heat source unit 5. The same treatment will apply to other components.

[0024] Figure 3 shows an example of the refrigerant circuit configuration for heat source unit 5a. The refrigerant circuits for heat source unit 5b and heat source unit 5c have a similar configuration.

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

[0026] Furthermore, the heat source unit 5a includes a heat exchanger 13 for exchanging heat between the refrigerant and the outside air, a fan 14, and an electronic expansion valve 16 for expanding the refrigerant. The heat source unit 5a may also include a switching valve (for example, a four-way switching valve) 12 for switching the circulation direction of the refrigerant. By including the switching valve 12, it becomes possible to handle both cooling and heating. The heat source unit 5a may also include an accumulator 15 provided in the suction side piping of the compressor 11 for purposes such as gas-liquid separation of the refrigerant.

[0027] The heat exchanger 21a in AHU2 shares refrigerant piping with the heat source unit 5a, and is configured to receive refrigerant directly from the heat source unit 5a.

[0028] An example of a refrigerant circulating in a refrigerant piping is a mildly flammable refrigerant with a low GWP (Global-warming potential). For example, this refers to all alternative refrigerants used in HFC refrigerant regulations to combat global warming (e.g., R1234yf[4], R1234ze(E)[4], R1233zd(E)[5], R32

[0675] , etc., where the numbers in brackets indicate the GWP (100-year value)) and refrigerants with a GWP (100-year value) of a similar magnitude. The type of refrigerant is not particularly limited, and other refrigerants such as brine or water may also be used. Since the operation of heat pump-type heat sources is well-known, a detailed explanation will be omitted here.

[0029] The compressors 11 of the heat source unit 5 do not all have to be of the same type. Examples of compressors 11 include scroll compressors and rotary compressors.

[0030] Figure 4 is a schematic diagram showing the overall configuration of the control system that controls the air conditioning system according to this embodiment. As shown in Figure 4, the air conditioning system 1 includes a system controller 10 and heat source unit controllers 8 (8a, 8b, 8c). The system controller 10 and the heat source unit controllers 8 (8a, 8b, 8c) are connected to each other via a communication line, and are configured to enable bidirectional communication.

[0031] Of the heat source unit controllers 8, the master unit, heat source unit controller 8a, controls the heat source system 3. For example, the heat source unit controller 8a controls the number of operating units of the multiple heat source units 5 according to the required capacity requested by the AHU 2 and / or the input information of the remote controller 29. Furthermore, the heat source controller 8a may perform capacity distribution control to allocate output capacity to the heat source units 5. For example, the heat source controller 8a transmits a start command, a stop command, and a target capacity command to each heat source controller 8.

[0032] Each heat source controller 8 controls the drive of the compressor 11, etc. (see Figure 3) based on the required capacity requested by the AHU 2 received from the system controller 10. It also controls the rotational speed of the compressor 11 based on the capacity command. For example, the heat source controller 8 has a calculation formula or table that converts the capacity command into a frequency command for the compressor 11, and uses this information to control the rotational speed of the compressor 11 according to the capacity command. Various control methods have been proposed for capacity control (output control) of the compressor 11, so it is possible to appropriately adopt a known method.

[0033] Figure 5 shows an example of the hardware configuration of the heat source controller 8. As shown in Figure 5, the heat source controller 8 includes, for example, a CPU (Central Processing Unit: processor) 31, main memory 32, secondary storage (memory) 33, and a communication interface 34. These components are interconnected directly or indirectly via a bus and work together to perform various processes.

[0034] The CPU 31 controls the entire heat source system using an OS (Operating System) stored in a secondary storage device 33 connected via a bus, and performs various processes by executing various programs stored in the secondary storage device 33. One or more CPUs 31 may be provided and may cooperate with each other to perform processing.

[0035] The main memory 32 consists of writable memory such as cache memory and RAM (Random Access Memory), and is used as a work area for reading the CPU 31's executable program and writing processing data by the executable program.

[0036] The secondary storage device 33 is a non-transitory computer-readable storage medium. Examples of secondary storage devices 33 include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memory. Examples of secondary storage devices 33 include ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), and flash memory. The secondary storage device 33 stores, for example, an OS for controlling the entire heat source system (such as Windows®, iOS®, and Android®), a BIOS (Basic Input / Output System), various device drivers for hardware operation of peripheral devices, various application software, and various data and files. The secondary storage device 33 also stores programs for implementing various processes and various data required to implement those processes. Multiple secondary storage devices 33 may be provided, and the aforementioned programs and data may be divided and stored in each secondary storage device 33. Furthermore, the secondary storage device 33 may be located on the cloud, and some of the programs and data stored in the secondary storage device 33 may also be located on the cloud.

[0037] The communication interface 34 functions as an interface for communicating with other devices via a communication line and for sending and receiving information. For example, the communication interface 34 communicates with other devices via wired or wireless means. Examples of wireless communication include communication via lines such as Bluetooth®, Wi-Fi, mobile communication systems (3G, 4G, 5G, 6G, LTE, etc.), and wireless LAN. An example of wired communication is communication via lines such as a wired LAN (Local Area Network).

[0038] Furthermore, the heat source controller 8 is also a computer and has the same configuration as the heat source controller 8a described above.

[0039] Figure 6 is a functional block diagram showing an example of the functions of the heat source controller. As shown in Figure 6, the heat source controller 8a includes a defrost information collection unit 41 and a capacity distribution unit 42.

[0040] The defrost information collection unit 41 collects information related to the defrost control of each heat source unit 5a, 5b, and 5c. Defrost control is a control method in which, while the air conditioning system 1 is in heating operation, it detects the temperature of the heat exchanger 13 of the heat source unit 5 and, when it falls below a predetermined threshold, determines that frost has formed on the heat exchanger 13, reverses the refrigerant cycle from the heating cycle to the cooling cycle to warm the heat exchanger 13 and melt the frost. The information related to defrost control is information on whether each heat source unit 5a, 5b, and 5c satisfies the defrost control conditions for determining the start of defrost control. Here, the defrost control condition is, for example, that the temperature of the heat exchanger 13 of the heat source unit 5 falls below a predetermined threshold, and when the defrost control condition is met, defrost control is started. Note that the defrost control conditions are not limited to those described above, and known conditions can be adopted as appropriate. In this manner, the defrost information collection unit 41 collects information to identify which of the heat source units 5 are in defrost control mode and which are in normal control mode. In this embodiment, the heat source unit 5 that is in defrost control mode is designated as heat source unit 5a. Alternatively, instead of the defrost information collection unit 41 determining whether or not the defrost control conditions are met, each heat source unit controller may determine whether or not the defrost control conditions are met, and if it determines that the defrost control conditions are met, it may notify the heat source unit controller 8a of a signal indicating this.

[0041] The defrost information collection unit 41 also acquires the operating capacity allocated to the heat source unit 5a that satisfies the defrost control conditions.

[0042] The capacity distribution unit 42 allocates the operating capacity required by one or more heat source units 5 that perform defrost control to the other heat source units 5. The capacity distribution unit 42 receives information from the defrost information collection unit 41 about the heat source unit 5a that enters defrost control and the operating capacity allocated to heat source unit 5a. Based on the information obtained from the defrost information collection unit 41, the capacity distribution unit 42 allocates the operating capacity of heat source unit 5a that enters defrost control to the other heat source units 5b and 5c that do not perform defrost control. At this time, if the operating capacity is to be allocated to a heat source unit 5b or 5c that is stopped, the capacity distribution unit 42 starts the stopped heat source unit 5b or 5c at the same time that heat source unit 5a satisfies the defrost control conditions.

[0043] When the defrost control conditions are met, the heat source unit 5a continues to operate and enters defrost control after a predetermined time has elapsed. The predetermined time is, for example, 40 seconds. Simultaneously with meeting the defrost control conditions, the heat source unit controller 8a may turn on an electric heater (not shown) provided in the heat source unit 5a to warm the heat transfer medium and maintain heating capacity.

[0044] When the heat source unit 5a enters defrost control mode, it prioritizes defrost control over commands from the heat source unit controller 8a. When defrost control is entered, the heat source unit 5a operates at the lowest capacity (e.g., 25%) that the compressor 11 can drive and performs defrosting. The operating capacity (minimum capacity) for the heat source unit 5a under defrost control is treated as an additional value outside the required capacity requested by the AHU2. During defrost control, the compressor 11 operates at a predetermined frequency. The heat source unit 5a performing defrost control lowers its operating priority so that it does not return to normal operation during defrost control.

[0045] When defrost control is performed, the cooling cycle is initiated and the frost on the heat exchanger 13 is melted. However, since cooled heat transfer fluid is supplied from the heat source unit 5a, the temperature of the heat transfer fluid supplied to the AHU2 may decrease. When the capacity distribution unit 42 detects that the temperature required by the AHU2 has not been reached, i.e., that the temperature of the heat transfer fluid has decreased, it increases the operating capacity of the heat source unit 5b or 5c, or increases the number of operating heat source units 5. Similarly, when the capacity distribution unit 42 detects that the required capacity from the AHU2 has increased during defrost control, it increases the operating capacity of the heat source unit 5b or 5c, or increases the number of operating heat source units 5.

[0046] When defrost control is complete, the heat source unit 5a stops. After defrost control is complete, the heat source unit 5a becomes operational again in response to a request from the heat source unit controller 8a.

[0047] Figure 7 is a flowchart showing an example of a processing procedure for a heat source system control method executed by a heat source controller according to one embodiment of the present disclosure.

[0048] In step S101, the defrost information collection unit 41 collects defrost information from each of the heat source units 5a, 5b, and 5c.

[0049] In step S102, the defrost information collection unit 41 determines whether any of the heat source units 5a, 5b, and 5c satisfy the defrost control conditions. If any of the heat source units 5a, 5b, and 5c satisfy the defrost control conditions, the process proceeds to steps S103 and S106. On the other hand, if none of the heat source units 5 satisfy the defrost control conditions, the process returns to step S101.

[0050] If any of the heat sources 5a, 5b, and 5c satisfy the defrost control conditions, in this case, if heat source 5a satisfies the defrost control conditions, heat source 5a continues to operate and waits for a predetermined time (S103).

[0051] In step S104, the heat source unit 5a performs defrost control.

[0052] In step S105, the heat source unit 5a stops when the defrost control is completed.

[0053] Furthermore, if it is determined in step S102 that the heat source unit 5a satisfies the defrost control conditions, the capacity distribution unit 42 obtains the operating capacity required for the heat source unit 5a from the defrost information collection unit 41 and distributes this operating capacity to the other heat source units 5b or 5c (S106). In this embodiment, the operating capacity is distributed to the heat source unit 5b.

[0054] In step S107, the capacity distribution unit 42 starts the heat source unit 5b. The capacity distribution unit 42 starts the heat source unit 5b at the same time that the heat source unit 5a satisfies the defrost control conditions.

[0055] In step S108, the capacity distribution unit 42 determines whether the heat source system 3 meets the required capacity requested by the AHU2. Specifically, it determines whether the heat transfer medium supplied by the heat source system 3 has reached the temperature required by the AHU2, and whether the required capacity from the AHU2 has increased during defrost control. If the temperature required by the AHU2 has been reached, or if the required capacity from the AHU2 has not increased and the required capacity is met, the process proceeds to step S109. On the other hand, if the temperature required by the AHU2 has not been reached, or if the required capacity from the AHU2 has increased and the required capacity is not met, the process returns to step S106.

[0056] If it is determined that the required capacity of AHU2 is met, each heat source unit 5a, 5b, and 5c continues operation (S109).

[0057] Figure 8 is a diagram showing the capacity distribution of a heat source unit by a heat source unit controller according to one embodiment of the present disclosure. In Figure 8, the vertical axis represents capacity (%), and the horizontal axis represents time. In Figure 8, the solid line represents the capacity of heat source unit 5a, the dashed line represents the capacity of heat source unit 5b, and the dashed line represents the capacity of heat source unit 5c.

[0058] At time t1, when the heat source controller 8a receives a request for 100% capacity from AHU2, it starts the heat source 5a at 100% operating capacity.

[0059] At time t2, the heat source unit 5a satisfies the defrost control conditions. The defrost information collection unit 41 collects this information and passes it to the capacity distribution unit 42. The capacity distribution unit 42 determines which heat source unit 5b to which 100% of the operating capacity of heat source unit 5a will be allocated. Heat source unit 5b is started at 100% of its operating capacity.

[0060] Meanwhile, the heat source unit 5a continues to operate and starts defrost control after a predetermined time has elapsed. At this point, the heat source unit 5a is considered to have met the defrost control conditions, that is, frost has formed on the heat exchanger 13, and therefore its operating capacity during continuous operation is below 100%.

[0061] At time t3, after a predetermined time has elapsed from time t2, the heat source unit 5a enters defrost control and enters the cooling cycle. When defrost control is entered, the heat source unit 5a performs defrosting at a minimum operating capacity of 25%, which is outside the required capacity. When the defrost control of the heat source unit 5a is completed at time t6, it stops.

[0062] At time t4, the heat source controller 8a receives an increase in the AHU2's requested capacity, specifically from 100% to 140%. The capacity distribution unit 42, knowing that the heat source 5b is already operating at 100%, decides to allocate the increase in requested capacity, 40%, to the heat source 5c. The heat source 5c is then started up at an operating capacity of 40%.

[0063] Furthermore, at time t5, the heat source controller 8a receives an increase in the AHU2's requested capacity, specifically from 140% to 160%. The capacity distribution unit 42 decides to allocate the increased requested capacity of 20% to the heat source unit 5c. The heat source unit 5c is then operated at 60% of its operating capacity.

[0064] Furthermore, at time t7, the heat source controller 8a receives an increase in the AHU2's requested capacity, specifically from 160% to 240%. The capacity distribution unit 42 decides to allocate 40% of the 80% increase in requested capacity to the heat source unit 5c. The heat source unit 5c is then operated at 100% of its operating capacity. The remaining 40% of the increased requested capacity is then allocated to the heat source unit 5a, which was stopped at time t6. The heat source unit 5a is started up at 40% of its operating capacity and resumes operation.

[0065] In this embodiment, the heat source controller 8a is equipped with a defrost information collection unit 41 and a capacity distribution unit 42 to control the number of operating heat source units 5 and their operating capacity. However, the system controller 10 may be provided with the functions that the master heat source controller 8a performs.

[0066] In other words, the system controller 10 calculates the required capacity and controls the number of operating units and operating capacity of the multiple heat source units 5 based on the calculated required capacity.

[0067] <Note> The heat source system, air conditioning system, control method, and control program described in the embodiments above can be understood, for example, as follows.

[0068] A heat source system (3) according to a first aspect of the present disclosure is a heat source system that supplies a heat medium to a user-side unit (2), comprising a plurality of heat source machines (5) and a heat source machine controller (8a) that controls the number of operating machines and the operating capacity of the plurality of heat source machines according to the required capacity required by the user-side unit, wherein the heat source machine controller collects information regarding the defrost control of the heat source machines and controls the allocation of the operating capacity required by one or more heat source machines that perform the defrost control to the other heat source machines.

[0069] The heat source controller aggregates information regarding the defrost control of the heat sources (defrost information), allowing it to determine which heat sources have entered defrost control mode or are operating under normal control. Based on this information, the operating capacity provided by the heat source that has entered defrost control mode can be distributed to the other heat sources, preventing the system from falling below the required capacity for the user unit and resolving capacity shortages.

[0070] In the first embodiment of the heat source system according to the second aspect of this disclosure, the heat source controller may increase the operating capacity or number of operating heat source units when it detects that the temperature required by the user unit has not been reached or when it detects an increase in the required capacity.

[0071] When defrost control is activated, the system switches from a heating cycle to a cooling cycle, supplying cool air and lowering the temperature of the user unit. Upon detecting this temperature drop, the heat source controller increases the operating capacity of the heat source unit or increases the number of operating heat source units to raise the temperature to the user unit's required level, thus resolving any capacity shortage. This also resolves capacity shortages if the user unit's required capacity increases.

[0072] In a third aspect of the present disclosure, the heat source system, in the first or second aspect, may start the defrost control after a predetermined time has elapsed since the defrost control conditions for determining the start of the defrost control were met.

[0073] This allows the heater to be heated to the desired temperature and used to warm the cold air when operating the heater to suppress the performance degradation of the heat source unit performing defrost control. It also provides other heat source units to which operating capacity is allocated with sufficient time to rise to their desired operating capacity.

[0074] In a third embodiment of the heat source system according to a fourth aspect of the present disclosure, the heat source controller may, when the heat source performing defrost control satisfies the defrost control conditions, request the other heat source units to provide the operating capacity required for the heat source performing defrost control.

[0075] This allows other heat source units to which operating capacity is assigned to have some leeway to reach their desired operating capacity.

[0076] In the fifth aspect of the heat source system of this disclosure, in any of the first to fourth aspects, the heat source unit that performs the defrost control may operate at the minimum operating capacity of the heat source unit during the defrost control.

[0077] As a result, the heat source unit performing defrost control can prioritize defrost control during defrost control, rather than following the control of the heat source unit controller.

[0078] In the heat source system according to the sixth aspect of this disclosure, in any of the first to fifth aspects, the heat source controller may stop the heat source when the defrost control of the heat source that performs the defrost control is completed.

[0079] This reduces the number of times the heat source is switched and allows for the maintenance of a stable output.

[0080] The heat source system of the seventh aspect of this disclosure includes, in any of the first to sixth aspects, a heat source controller (8) provided corresponding to each of the plurality of heat source machines and controlling the corresponding heat source machine, wherein any one of the heat source controllers may include the controller.

[0081] This eliminates the need for a system controller, thereby reducing costs.

[0082] An air conditioning system (1) according to the eighth aspect of this disclosure comprises a heat source system disclosed in any of the first to sixth aspects and an air handling unit (2) supplied with a heat transfer medium from the heat source system.

[0083] A control method according to a ninth aspect of this disclosure is a control method for a heat source system comprising a plurality of heat source units that supply a heat transfer medium to a user-side unit, wherein a computer collects information regarding the defrost control of the heat source units and performs control to allocate the operating capacity required by one or more heat source units that perform the defrost control to the other heat source units.

[0084] A control program in the tenth aspect of this disclosure causes a computer to function as the heat source controller in any of the first to seventh aspects of the disclosure. [Explanation of symbols]

[0085] 1: Air conditioning system 2: AHU (Direct Inflation Air Handling Unit) (User-side unit) 3: Heat source system 5: Heat source machine 5a: Heat source machine 5b: Heat source machine 5c: Heat source machine 7: Cabinet 8: Heat source unit controller 8a: Heat source controller (master) 8b: Heat source controller (slave 1) 8c: Heat source controller (slave 2) 10: System Controller 11: Compressor 12: Switching valve 13:Heat exchanger 14: Fan 15: Accumulator 16: Electronic expansion valve 21:Heat exchanger 21a: Heat exchanger 21b: Heat exchanger 21c: Heat exchanger 22: Temperature sensor 22a: Temperature sensor 22b: Temperature sensor 22c: Temperature sensor 23: Fan 24: Suction sensor 29: Remote controller 31: CPU 32: Main memory 33:Secondary storage device 34: Communication Interface 41: Defrost Information Gathering Unit 42: Capability Allocation Department

Claims

1. A heat source system that supplies a heat transfer medium to a user-side unit, Multiple heat source units, A controller that controls the number of operating units and operating capacity of the multiple heat source units according to the required capacity required by the user-side unit. Equipped with, The controller collects information regarding the defrost control of the heat source unit and performs control to allocate the operating capacity required by one or more heat source units that perform the defrost control to the other heat source units. The heat source unit that performs the defrost control starts the defrost control after a predetermined time has elapsed since the defrost control conditions for determining the start of the defrost control were met. A heat source system in which the heat source unit that performs the defrost control operates at the minimum operating capacity of the heat source unit during the defrost control.

2. The heat source system according to claim 1, wherein the controller increases the operating capacity or the number of operating units of the heat source machine when it detects that the user unit has not reached the required temperature or when it detects an increase in the required capacity.

3. The heat source system according to claim 1, wherein the controller, when the heat source unit performing the defrost control satisfies the defrost control conditions, requests the other heat source units to provide the operating capacity required for the heat source unit performing the defrost control.

4. The heat source system according to claim 1, wherein the controller stops the heat source when the defrost control of the heat source that performs the defrost control is completed.

5. Each of the multiple heat source units is provided with a heat source unit controller that controls the corresponding heat source unit, A heat source system according to any one of claims 1 to 4, wherein any one of the heat source controllers includes the controller.

6. The heat source system according to claim 1, An air handling unit to which a heat transfer medium is supplied from the heat source system and An air conditioning system equipped with [specific features / features].

7. A control method for a heat source system that includes multiple heat source units and supplies a heat transfer medium to a user-side unit, Information regarding the defrost control of the heat source unit is collected, and the operating capacity required by one or more heat source units that perform the defrost control is allocated to the other heat source units. The heat source unit that performs the defrost control starts the defrost control after a predetermined time has elapsed since the defrost control conditions for determining the start of the defrost control were met. A control method in which a computer executes a control to operate the heat source unit performing the defrost control at its minimum operating capacity during the defrost control.

8. A control program for causing a computer to function as the controller described in any one of claims 1 to 4.

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