EP4589208A1

EP4589208A1 - Heat source system, air conditioning system, control method and control program

Info

Publication number: EP4589208A1
Application number: EP22959493.2A
Authority: EP
Inventors: Satoru Saegusa; Tetsuji Fujino
Original assignee: Mitsubishi Heavy Industries Thermal Systems Ltd
Current assignee: Mitsubishi Heavy Industries Thermal Systems Ltd
Priority date: 2022-09-20
Filing date: 2022-09-20
Publication date: 2025-07-23
Also published as: WO2024062529A1; JPWO2024062529A1; EP4589208A4

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

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

Background Art

In the related art, an air-conditioning system is known, which includes a heat source system having a plurality of heat source machines and a usage-side unit that performs air conditioning by using a heat medium supplied from the heat source system. In such an air-conditioning system, when the heat source machine enters defrost control, the corresponding heat source machine is in a cooling cycle, and thus a capacity of the air-conditioning system is reduced.
On the other hand, PTL 1 discloses that in a heat pump system, when any module enters a defrost operation, it is considered that the other modules are also in a state of being likely to enter the defrost operation, and in order to avoid entering the defrost operation, a heat load is not applied by multiplying an allowance rate.
In addition, PTL 2 discloses that information indicating that a defrost operation is performed in one outdoor unit is transmitted to another outdoor unit, and when information indicating that the defrost operation is performed in the other outdoor unit is received when a heating operation is performed in the one outdoor unit, the defrost operation is not performed and the heating operation is continued.

Citation List

Patent Literature

[PTL 1] Japanese Unexamined Patent Application Publication No. 2015-158337
[PTL 2] International Publication No. WO2018/016000

Summary of Invention

Technical Problem

However, in the inventions of PTLS 1 and 2, there has been no study on a case where an operation capacity for which the heat source machine performing the defrost control was responsible is reduced by the defrost control and a capacity of an entire air-conditioning system is reduced.
The present disclosure has been made in view of such circumstances, and an object thereof is to provide a heat source system, an air-conditioning system, a control method, and a control program that prevent a decrease in capacity when defrost control is performed.

Solution to Problem

In order to achieve the above-described object, a heat source system, an air-conditioning system, a control method, and a control program of the present disclosure employ the following means.
A heat source system of the present disclosure is a heat source system that supplies a heat medium to a usage-side unit, the heat source system including: a plurality of heat source machines; and a controller that controls the number of the plurality of heat source machines in operation and an operation capacity of the plurality of heat source machines according to a required capacity required by the usage-side unit, in which the controller performs control of collecting information related to defrost control of the heat source machine and allocating the operation capacity required for one or more heat source machines that perform the defrost control to another heat source machine.
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.
A control method 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 usage-side unit, the method being executed by a computer and including: performing control of collecting information related to defrost control of the heat source machine and allocating an operation capacity required for one or more heat source machines that perform the defrost control to another heat source machine.
A control program of the present disclosure causes a computer to function as the controller.

Advantageous Effects of Invention

According to the heat source system of the present disclosure, it is possible to grasp which heat source machine has entered the defrost control. Based on this information, it is possible to allocate an operation capacity covered by a heat source machine that has entered the defrost control to another heat source machine, and to prevent the operation capacity from falling below a required capacity required by a usage-side unit and to solve a capacity deficiency.

Brief Description of Drawings

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 heat source machine controller according to an embodiment of the present disclosure.
Fig. 6 is a functional block diagram showing an example of a function included in the heat source machine controller according to an embodiment of the present disclosure.
Fig. 7 is a flowchart showing an example of the processing procedure of a control method for the heat source system executed by the heat source machine controller according to an embodiment of the present disclosure.
Fig. 8 is a diagram showing a capacity allocation of the heat source machine by the heat source machine controller according to an embodiment of the present disclosure. Description of Embodiments

(Configuration of Air-Conditioning System)

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.
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 a usage-side unit 2, but the present disclosure is not limited thereto. The usage-side unit 2 may be another type of air handling unit such as a cold/hot water type air handling unit. In addition, the usage-side unit 2 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 3.
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 (not shown), a heat exchanger 21 (21a, 21b, and 21c), a temperature sensor 22 (22a, 22b, and 22c), a fan 23, and a temperature sensor 24. The heat exchanger 21 (21a, 21b, and 21c), the temperature sensor 22 (22a, 22b, and 22c), the fan 23, and the temperature sensor 24 are disposed, for example, inside a housing 7.
The total heat exchanger 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 is sent to the heat exchanger 21. The heat exchanger 21 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 after passing through a pipe.
The 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 may be a position where the temperature of the air after heat exchange in the heat exchanger 21 can be measured.
A system controller 10 (AHU controller) calculates a required capacity based on a difference between the set temperature set by the remote controller (not shown) and the temperature measured by the temperature sensor 24, and outputs the required capacity 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 measured temperature. The calculation of the required capacity is known, and various known techniques may be appropriately adopted.
In addition, the system controller 10 controls the rotation speeds of the fan 23. The control by the system controller 10 may adopt a known technique, and a detailed description thereof will be omitted.
The heat source system 3 includes a heat source machine controller 8 (8a, 8b, and 8c), and for example, the heat source machine controller (controller) 8a is set as a master machine. The heat source machine controller 8a controls the operating condition and output capacity of each heat source machine 5 (5a, 5b, and 5c) via each heat source machine controller 8.
The heat source machine controller 8 may control the operating condition and output capacity of each heat source machine 5 based on the information input by a remote controller 29.
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.
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 21 included in the AHU 2 has a configuration in which a plurality of heat exchangers 21a, 21b, and 21c are integrated. In the present embodiment, the heat source machine 5a is configured to individually supply the heat medium to the heat exchanger 21a, the heat source machine 5b is configured to individually supply the heat medium to the heat exchanger 21b, and the heat source machine 5c is configured to individually supply the heat medium to the heat exchanger 21c. The correspondence relationship between the heat source machine 5 and the heat exchanger 21 is not limited to this example, and a known refrigerant connection form can be appropriately adopted.
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.
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.
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.
In addition, the heat source machine 5a includes a 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.
The heat exchanger 21a 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.
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.
Since the operation of the heat source machine of the heat pump type is known, a detailed description thereof will be omitted.
The types of the compressors 11 of the heat source machine 5 do not have to be the same. Examples of the compressor 11 include a scroll compressor and a rotary compressor.
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 the system controller 10, and the heat source machine controller 8 (8a, 8b, and 8c).
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.
Among the heat source machine controllers 8, the heat source machine controller 8a which is the master machine controls the heat source system 3. For example, the heat source machine controller 8a 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 and/or the input information of the remote controller 29.
In addition, the heat source machine controller 8a may perform capacity allocation control for allocating an output capacity to the heat source machine 5. The heat source machine controller 8a transmits, for example, an activation command, a stop command, and a target capacity command to each heat source machine controller 8.
Each heat source machine controller 8 controls the driving of the compressor 11 (refer to Fig. 3) and the like based on the required capacity required by the AHU 2 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 11 have been proposed, it is possible to appropriately adopt the known method.
Fig. 5 is a diagram showing an example of a hardware configuration of the heat source machine controller 8. As shown in Fig. 5, the heat source machine controller 8 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.
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.
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.
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.
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).
The heat source machine controller 8 is also a computer and has the same configuration as the heat source machine controller 8a described above.
Fig. 6 is a functional block diagram showing an example of a function included in the heat source machine controller. As shown in Fig. 6, the heat source machine controller 8a includes a defrost information collecting unit 41 and a capacity allocation unit 42.
The defrost information collecting unit 41 collects information related to defrost control of each of the heat source machines 5a, 5b, and 5c. The defrost control is control in which the air-conditioning system 1 determines that frost has been formed on the heat exchanger 13 when the temperature of the heat exchanger 13 of the heat source machine 5 is equal to or lower than a predetermined threshold value while measuring the temperature of the heat exchanger 13 during the heating operation, and reverses the refrigerant cycle from the heating cycle to the cooling cycle to warm the heat exchanger 13 and melt the frost. In addition, the information related to the defrost control is information on whether or not each of the heat source machines 5a, 5b, and 5c satisfies the defrost control condition for determining the start of the defrost control. Here, the defrost control condition is, for example, that the temperature of the heat exchanger 13 of the heat source machine 5 described above is equal to or lower than a predetermined threshold value, and when the defrost control condition is satisfied, the defrost control is started. The defrost control condition is not limited to the above, and a known condition can be appropriately adopted. In this way, the defrost information collecting unit 41 collects information for grasping the heat source machine 5 that enters the defrost control and the heat source machine 5 that is under the normal control, among the heat source machines 5. In the present embodiment, the heat source machine 5 that enters the defrost control is the heat source machine 5a. In addition, instead of the defrost information collecting unit 41 determining whether or not the defrost control condition is satisfied, each heat source machine controller may determine whether or not the defrost control condition is satisfied, and when it is determined that the defrost control condition is satisfied, a signal indicating that may be notified to the heat source machine controller 8a.
In addition, the defrost information collecting unit 41 acquires the operation capacity allocated to the heat source machine 5a that satisfies the defrost control condition.
The capacity allocation unit 42 allocates the operation capacity required for one or more heat source machines 5 performing defrost control to another heat source machine 5. The capacity allocation unit 42 receives information on the heat source machine 5a that enters the defrost control and on the operation capacity allocated to the heat source machine 5a from the defrost information collecting unit 41. The capacity allocation unit 42 allocates the operation capacity of the heat source machine 5a that enters the defrost control to the other heat source machines 5b and 5c that do not perform the defrost control, based on the information acquired from the defrost information collecting unit 41. At this time, in a case where the operation capacity is allocated to the heat source machine 5b or 5c that is stopped, the capacity allocation unit 42 activates the heat source machine 5b or 5c that is stopped at the same time when the heat source machine 5a satisfies the defrost control condition.
When the heat source machine 5a satisfies the defrost control condition, the heat source machine 5a enters the defrost control after a predetermined time has elapsed while continuing the operation. The predetermined time is, for example, 40 seconds. The heat source machine controller 8a may maintain the heating capacity by turning on an electric heater (not shown) provided in the heat source machine 5a to warm the heat medium at the same time when the defrost control condition is satisfied.
When the heat source machine 5a enters the defrost control, the heat source machine 5a does not follow the command from the heat source machine controller 8a, and prioritizes the defrost control. When the heat source machine 5a enters the defrost control, the heat source machine 5a operates at a lowest capacity (for example, 25%) at which the compressor 11 can be driven, and performs defrosting. The operation capacity (lowest capacity) for the heat source machine 5a for which the defrost control is performed is treated as an outside number of the required capacity required from the AHU 2. During the defrost control, the compressor 11 operates at a frequency determined in advance. The heat source machine 5a performing the defrost control lowers the operation priority not to return to the normal operation again during the defrost control.
When the heat source machine 5a performs the defrost control, the heat source machine 5a is in the cooling cycle and the frost on the heat exchanger 13 is melted. However, the heat medium cooled by the heat source machine 5a is supplied. Therefore, the temperature of the heat medium supplied to the AHU 2 may decrease. When the capacity allocation unit 42 detects that the temperature required by the AHU 2 has not been reached, that is, the temperature of the heat medium has decreased, the capacity allocation unit 42 increases the operation capacity of the heat source machine 5b or 5c or increases the number of the heat source machines 5 in operation. In addition, when the capacity allocation unit 42 detects that the required capacity has increased from the AHU 2 during the defrost control, the capacity allocation unit 42 increases the operation capacity of the heat source machine 5b or 5c or increases the number of the heat source machines 5 in operation in the same manner.
When the defrost control ends, the heat source machine 5a is stopped. After the defrost control ends, the heat source machine 5a can be operated in response to a request from the heat source machine controller 8a.
Fig. 7 is a flowchart showing an example of the processing procedure of a control method for the heat source system executed by the heat source machine controller according to an embodiment of the present disclosure.
In step S101, the defrost information collecting unit 41 collects defrost information on each of the heat source machines 5a, 5b, and 5c.
In step S102, the defrost information collecting unit 41 determines whether or not any one of the heat source machines 5a, 5b, and 5c satisfies the defrost control condition. When any one of the heat source machines 5a, 5b, and 5c satisfies the defrost control condition, the process proceeds to steps S103 and S106. On the other hand, when neither of the heat source machines 5 satisfies the defrost control condition, the process returns to step S101 again.
When any one of the heat source machines 5a, 5b, and 5c satisfies the defrost control condition, here, when the heat source machine 5a satisfies the defrost control condition, the heat source machine 5a stands by for a predetermined time while continuing the operation (S103).
In step S104, the heat source machine 5a performs defrost control.
In step S105, when the defrost control ends, the heat source machine 5a is stopped.
In addition, when it is determined in step S102 that the heat source machine 5a satisfies the defrost control condition, the capacity allocation unit 42 acquires the operation capacity required for the heat source machine 5a from the defrost information collecting unit 41 and allocates the operation capacity to the other heat source machine 5b or 5c (S106). In the present embodiment, it is assumed that the operation capacity is allocated to the heat source machine 5b.
In step S107, the capacity allocation unit 42 activates the heat source machine 5b. The capacity allocation unit 42 activates the heat source machine 5b at the same time when the heat source machine 5a satisfies the defrost control condition.
In step S108, the capacity allocation unit 42 determines whether or not the heat source system 3 satisfies the required capacity required by the AHU 2. Specifically, the capacity allocation unit 42 determines whether or not the heat medium supplied by the heat source system 3 has reached the temperature required by the AHU 2 and whether or not the required capacity has increased from the AHU 2 during the defrost control. In a case where the temperature required by the AHU 2 has been reached or the required capacity from the AHU 2 has not increased and the required capacity is satisfied, the process proceeds to step S109. On the other hand, in a case where the temperature required by the AHU 2 has not been reached or the required capacity from the AHU 2 has increased and the required capacity is not satisfied, the process returns to step S106 again.
When it is determined that the required capacity required by the AHU 2 is satisfied, each of the heat source machines 5a, 5b, and 5c continues the operation (S109).
Fig. 8 is a diagram showing a capacity allocation of the heat source machine by the heat source machine controller according to an embodiment of the present disclosure. The vertical axis of Fig. 8 represents the capacity (%), and the horizontal axis represents time. A solid line in Fig. 8 indicates the capacity of the heat source machine 5a, a broken line indicates the capacity of the heat source machine 5b, and a one-dot chain line indicates the capacity of the heat source machine 5c.
When the required capacity of 100 (%) is received from the AHU 2 at time t1, the heat source machine controller 8a activates the heat source machine 5a at an operation capacity of 100 (%).
At time t2, the heat source machine 5a satisfies the defrost control condition. The defrost information collecting unit 41 collects this information and passes the information to the capacity allocation unit 42. The capacity allocation unit 42 determines the heat source machine 5b to which the operation capacity of 100 (%) of the heat source machine 5a is allocated. The heat source machine 5b is activated at the operation capacity of 100 (%).
Meanwhile, the heat source machine 5a starts the defrost control after a predetermined time has elapsed while continuing the operation. Here, the heat source machine 5a satisfies the defrost control condition, that is, it is considered that frost is formed on the heat exchanger 13. Therefore, the operation capacity during the operation in progress falls below 100 (%).
At time t3 after a predetermined time has elapsed from the time t2, the heat source machine 5a enters defrost control, and is in a cooling cycle. When the heat source machine 5a enters the defrost control, the heat source machine 5a performs defrosting at the lowest operation capacity of 25 (%) as the outside number of the required capacity. When the defrost control ends at time t6, the heat source machine 5a is stopped.
At time t4, the heat source machine controller 8a receives an increase in the required capacity of the AHU 2, specifically, an increase from 100 (%) to 140 (%). The capacity allocation unit 42 determines to allocate 40 (%), which is an increase in the required capacity, to the heat source machine 5c since the heat source machine 5b is already operated at 100 (%). The heat source machine 5c is activated at the operation capacity of 40 (%).
Further, at time t5, the heat source machine controller 8a receives an increase in the required capacity of the AHU 2, specifically, an increase from 140 (%) to 160 (%). The capacity allocation unit 42 determines to allocate 20 (%), which is an increase in the required capacity, to the heat source machine 5c. The heat source machine 5c is operated at the operation capacity of 60 (%).
Further, at time t7, the heat source machine controller 8a receives an increase in the required capacity of the AHU 2, specifically, an increase from 160 (%) to 240 (%). The capacity allocation unit 42 determines to allocate 40 (%) of the increase of 80 (%) in the required capacity to the heat source machine 5c. The heat source machine 5c is operated at the operation capacity of 100 (%). In addition, the capacity allocation unit 42 determines to allocate the remainder of 40 (%) of the increase in the required capacity to the heat source machine 5a stopped at the time t6. The heat source machine 5a is activated at the operation capacity of 40 (%), and starts operation again.
In the present embodiment, the heat source machine controller 8a includes the defrost information collecting unit 41 and the capacity allocation unit 42 to control the number of the heat source machines 5 in operation and the operation capacity of the heat source machine 5. However, the functions performed by the master heat source machine controller 8a may be provided in the system controller 10.
That is, the system controller 10 calculates the required capacity and controls the number of the plurality of heat source machines 5 in operation and the operation capacity of the plurality of heat source machines 5 based on the calculated required capacity.

The heat source system, the air-conditioning system, the control method, and the control program described in the above-described embodiment are grasped as follows, for example.
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 usage-side unit (2), the heat source system including: a plurality of heat source machines (5); and a heat source machine controller (8a) that controls the number of the plurality of heat source machines in operation and an operation capacity of the plurality of heat source machines according to a required capacity required by the usage-side unit, in which the heat source machine controller performs control of collecting information related to defrost control of the heat source machine and allocating the operation capacity required for one or more heat source machines that perform the defrost control to another heat source machine.
Since the heat source machine controller integrates the information (defrost information) related to the defrost control of the heat source machine, it is possible to grasp which heat source machine has entered the defrost control or is subject to normal control. Based on this information, it is possible to allocate an operation capacity covered by a heat source machine that has entered the defrost control to another heat source machine, and to prevent the operation capacity from falling below a required capacity required by a usage-side unit and to solve a capacity deficiency.
In a heat source system according to a second aspect of the present disclosure, in the first aspect, the heat source machine controller may increase the operation capacity of the heat source machine or the number of the heat source machines in operation when the heat source machine controller detects that a temperature required by the usage-side unit has not been reached or detects an increase in the required capacity.
When the heat source machine enters the defrost control, the cycle is switched from the heating cycle to the cooling cycle, so that cold air is supplied and the temperature of the usage-side unit is lowered. When the decrease in temperature is detected, the heat source machine controller can increase the operation capacity of the heat source machine or increase the number of heat source machines in operation to satisfy the request by raising the temperature to the temperature required by the usage-side unit, and can solve the capacity deficiency. In addition, even when the required capacity of the usage-side unit increases, it is possible to solve the capacity deficiency.
In a heat source system according to a third aspect of the present disclosure, in the first aspect or the second aspect, the heat source machine that performs the defrost control may start the defrost control after a predetermined time has elapsed after the heat source machine satisfies a defrost control condition for determining a start of the defrost control.
Accordingly, in a case where the heater is operated to suppress a decrease in the capacity of the heat source machine performing the defrost control, the heater can be warmed to a desired temperature, and the cold air can be warmed by the heater. In addition, a grace period for the capacity being increased to the desired operation capacity can be given to another heat source machine to which the operation capacity is allocated.
In a heat source system according to a fourth aspect of the present disclosure, in the third aspect, the heat source machine controller may require the operation capacity required for the heat source machine that performs the defrost control from the other heat source machine when the heat source machine that performs the defrost control satisfies the defrost control condition.
In addition, a grace period in which the capacity is increased to the desired operation capacity can be given to another heat source machine to which the operation capacity is allocated.
In a heat source system according to a fifth aspect of the present disclosure, in any one of the first aspect to the fourth aspect, the heat source machine that performs the defrost control may operate at a lowest operation capacity of the heat source machine during the defrost control.
Accordingly, the heat source machine performing the defrost control can prioritize the defrost control and perform the defrost control without following the control of the heat source machine controller during the defrost control.
In a heat source system according to a sixth aspect of the present disclosure, in any one of the first aspect to the fifth aspect, the heat source machine controller may stop the heat source machine that performs the defrost control when the defrost control of the heat source machine ends.
In this manner, the number of times the heat source machine is switched can be reduced, and a stable output can be maintained.
A heat source system of a seventh aspect of the present disclosure may include, in any one of the first aspect to the sixth aspect, a heat source machine controller (8) provided to correspond to each of the plurality of the heat source machines and controlling a corresponding heat source machine, in which one of the heat source machine controllers may include the controller.
In this manner, the system controller can be omitted, and the cost can be reduced.
An air-conditioning system (1) of an eighth aspect of the present disclosure includes the heat source system according to any one of the first aspect to the sixth aspect, and an air handling unit (2) to which a heat medium is supplied from the heat source system.
A control method of a ninth aspect 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 usage-side unit, the method being executed by a computer and including: performing control of collecting information related to defrost control of the heat source machine and allocating an operation capacity required for one or more heat source machines that perform the defrost control to another heat source machine.
A control program of a tenth aspect of the present disclosure causes a computer to function as the heat source machine controller according to any one of the first aspect to the seventh aspect.

Reference Signs List

1: Air-conditioning system
2: AHU (direct expansion type air handling unit) (usage-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 (master)
8b: Heat source machine controller (slave 1)
8c: Heat source machine controller (slave 2)
10: System controller
11: Compressor
12: Switching valve
13: Heat exchanger
14: Fan
15: Accumulator
16: Electron 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
34: Communication interface
41: Defrost information collecting unit
42: Capacity allocation unit

Claims

A heat source system that supplies a heat medium to a usage-side unit, the heat source system comprising:
a plurality of heat source machines; and

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

wherein the controller performs control of collecting information related to defrost control of the heat source machine and allocating the operation capacity required for one or more heat source machines that perform the defrost control to another heat source machine.
The heat source system according to Claim 1,
wherein the controller increases the operation capacity of the heat source machine or the number of the heat source machines in operation when the controller detects that a temperature required by the usage-side unit has not been reached or detects an increase in the required capacity.
The heat source system according to Claim 1,
wherein the heat source machine that performs the defrost control starts the defrost control after a predetermined time has elapsed after the heat source machine satisfies a defrost control condition for determining a start of the defrost control.
The heat source system according to Claim 3,
wherein the controller requires the operation capacity required for the heat source machine that performs the defrost control from the other heat source machine when the heat source machine that performs the defrost control satisfies the defrost control condition.
The heat source system according to Claim 1,
wherein the heat source machine that performs the defrost control operates at a lowest operation capacity of the heat source machine during the defrost control.
The heat source system according to Claim 1,
wherein the controller stops the heat source machine that performs the defrost control when the defrost control of the heat source machine ends.
The heat source system according to any one of Claims 1 to 6, further comprising:
a heat source machine controller provided to correspond to each of the plurality of the heat source machines and controlling a corresponding heat source machine,

wherein one of the heat source machine controllers includes the controller.
An air-conditioning system comprising:
the heat source system according to Claim 1; and

an air handling unit to which a heat medium is supplied from the heat source system.
A control method for a heat source system including a plurality of heat source machines and supplying a heat medium to a usage-side unit, the method being executed by a computer and comprising:
performing control of collecting information related to defrost control of the heat source machine and allocating an operation capacity required for one or more heat source machines that perform the defrost control to another heat source machine.
A control program for causing a computer to function as the controller according to any one of Claims 1 to 6.