EP4589209A1

EP4589209A1 - Heat source system, air-conditioning system, control method, and program

Info

Publication number: EP4589209A1
Application number: EP22959495.7A
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: WO2024062531A1; JPWO2024062531A1; EP4589209A4

Abstract

Provided are a heat source system, an air-conditioning system, a control method, and a program, with which it is possible to reduce a deficiency in the cooling/heating output when heat source machines are switched. The heat source system (3) supplies a heat medium to a usage-side unit (2), and comprises a plurality of heat source machines (5) and a controller (8) for controlling the plurality of heat source machines in accordance with a required capacity required by the usage-side unit. When switching occurs, in which a heat source machine being operated is switched, the controller provides a protected activation period for operating a newly activated first heat source machine (5b) at a fixed output, and stops a second heat source machine (5a) that is subject to switching after the protected activation period has elapsed.

Description

Technical Field

The present disclosure relates to a heat source system, an air-conditioning system, a control method, and a 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 (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 usage-side unit.
In the control in the related art, for example, control is performed to switch a heat source machine to be operated every predetermined time so that a load is not concentrated on a specific heat source machine being operated by operating the heat source machine for a long time.

Citation List

Patent Literature

[PTL 1] Japanese Unexamined Patent Application Publication No. 2021-139512

Summary of Invention

Technical Problem

When switching the heat source machine to be operated, in a case where a heat source machine (hereinafter, referred to as a "stop-side heat source machine") that has been operated so far is stopped, the heat source machine can be stopped relatively quickly. Meanwhile, in a case where a heat source machine (hereinafter, referred to as an "activation-side heat source machine") that has been stopped until now is activated, it takes a relatively long time until an output is stabilized. Therefore, when switching the heat source machine to be operated, a temporary output deficiency occurs with respect to the required capacity.
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 program capable of reducing an output deficiency of a cooling/heating capacity at the time of switching a heat source machine.

Solution to Problem

A heat source system according to an aspect in some embodiments 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 plurality of heat source machines according to a required capacity required by the usage-side unit, in which the controller provides a protection activation period in which a first heat source machine to be newly activated is operated at a fixed output, and stops a second heat source machine to be switched after the protection activation period has elapsed, at the time of switching at which the heat source machine to be operated is switched.
An air-conditioning system according to an aspect in some embodiments 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 for a heat source system according to an aspect in some embodiments 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 including: providing a protection activation period in which a first heat source machine to be newly activated is operated at a fixed output and stopping a second heat source machine to be switched after the protection activation period has elapsed, at the time of switching at which the heat source machine to be operated is switched.
A program according to an aspect in some embodiments of the present disclosure is a program for causing a computer to function as the controller. Advantageous Effects of Invention
According to the present disclosure, there is an effect that a reduction in the cooling/heating capacity can be suppressed.

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 an example diagram of control for keeping an output capacity of the heat source machine constant in rotation control of the heat source system according to an embodiment of the present disclosure.
Fig. 8 is an example diagram of a transition of a target capacity transmitted to each heat source machine in rotation control according to an embodiment of the present disclosure.
Fig. 9 is an example diagram of a transition of an output capacity of each heat source machine in the rotation control according to an embodiment of the present disclosure.

Description of Embodiments

(Configuration of Air-Conditioning System)

Hereinafter, an embodiment of a heat source system, an air-conditioning system, a control method, 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 the usage-side unit, but the present disclosure is not limited thereto. The usage-side unit may be another type of air handling unit such as a cold/hot water type air handling unit. In addition, the usage-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.
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 input 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.
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.
In the heat source machine controller 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.
The 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 target capacity command. For example, the heat source machine controller 8 has an arithmetic expression or a table for converting the target capacity command into a frequency command of the compressor 11, and controls the rotation speed of the compressor 11 corresponding to the target 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.
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 system controller 10 is also a computer and has the same configuration as the heat source machine controller 8 described above.
Fig. 6 is a functional block diagram showing an example of a function included in the heat source machine controller 8a. As shown in Fig. 6, the heat source machine controller 8a includes a storage unit 41, a number-of-machines control unit 42, and a capacity allocation unit 43.
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 stop threshold values for stopping each of the heat source machines.
Further, the storage unit 41 stores a rate (change rate) for increasing or decreasing the target capacity to be described later.
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 stop threshold value for stopping the heat source machine 5c, and the stop threshold value for stopping the heat source machine 5b are set. Each activation threshold value and each stop threshold value are appropriately set in consideration of the rated capacity and the activation priority of each heat source machine 5.
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.
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.
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.
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 stop of the heat source machine 5 based on the target capacity.
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.
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 target 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.
In addition, in a case where the system controller 10 has a function as a master machine that controls the heat source system 3, the system controller 10 may have the same functions as the heat source machine controller 8a. In that case, each heat source machine controller 8 is a slave machine that is operated by a command of the system controller 10.
In addition, in a case where the heat source system 3 is controlled by the system controller 10, the system controller 10 includes a configuration and a function for realizing the above-described configuration and function included in the heat source machine controller 8a.

(Rotation Control)

Fig. 7 is a diagram for describing rotation control of the heat source system according to the present embodiment. In the following description, a case where the required capacity is 80% of the rated capacity of one heat source machine, the output capacity of each heat source machine is the same, and the priorities are set in the order of the heat source machines 5a, 5b, and 5c will be described as an example.
First, a state 1 in Fig. 7 is a diagram showing a state before the switching of the heat source machine. In the state 1, the target capacity of 80% is allocated to the heat source machine 5a, and thus the required capacity of the usage-side unit is covered by the heat source machine 5a. In this state, the heat source machines 5b and 5c are in a stopped state.
Next, a state 2 in Fig. 7 is a diagram showing a state at the time of switching the heat source machine, specifically, in a protection activation period. In the protection activation period at the time of switching the heat source machine, the capacity allocation unit 43 determines the target capacity of each of the heat source machines 5a and 5b by allocating the required capacity to the heat source machine 5a and to the heat source machine 5b, and operates both of the heat source machines 5a and 5b. As an example, the capacity allocation unit 43 allocates a certain target capacity to the heat source machine 5b (first heat source machine) to be newly activated. The capacity allocation unit 43 allocates, for example, 25%, which is the minimum capacity, to the heat source machine 5b. In addition, the capacity allocation unit 43 allocates the target capacity to the heat source machine 5a such that the sum of the target capacities allocated to the heat source machines 5a and 5b matches the target capacity allocated to the heat source machine 5a (second heat source machine) immediately before the switching of the heat source machine.
Further, the controller 8a sets the priority of the heat source machine controller 8a corresponding to the heat source machine 5a to be stopped to the lowest priority, and sets the priority of the heat source machine controller 8b corresponding to the heat source machine 5b to be newly activated to the highest priority.
A state 3 in Fig. 7 is a diagram showing a state after the switching of the heat source machine. In the state 3, the target capacity of 80% is allocated to the heat source machine 5b, and thus the required capacity of the usage-side unit is covered by the heat source machine 5b.
Fig. 8 is an example diagram of a transition of a target capacity allocated to each heat source machine in the rotation control. In addition, Fig. 9 is an example diagram of a transition of an output capacity of each heat source machine in the rotation control. In Figs. 8 and 9, a broken line indicates a target capacity or output capacity corresponding to the heat source machine 5a. In addition, the one-dot chain line indicates a target capacity or output capacity corresponding to the heat source machine 5b. In addition, the solid line indicates a target capacity or output capacity corresponding to the heat source machine 5c.
Hereinafter, rotation control in the present embodiment will be described with reference to Figs. 8 and 9.
As shown in Fig. 8, before rotation time t1, that is, before the switching of the heat source machine, the target capacity of 80% is allocated to the heat source machine 5a, so that the required capacity of the usage-side unit is covered. At this time, as shown in Fig. 9, the heat source machine 5a is operated at an output capacity of 80% based on the target capacity of 80%, until the rotation time t1.
Next, at the rotation time t1, the heat source machine controller 8a transmits the activation command to the heat source machine controller 8b. The heat source machine controller 8b activates the heat source machine 5b based on the activation command. In addition, at the rotation time t1 in Fig. 8, the capacity allocation unit 43 allocates 25%, which is the minimum capacity, as the target capacity to the heat source machine 5b to be newly activated. In addition, the capacity allocation unit 43 allocates the target capacity of 55% to the heat source machine 5a such that the sum of the target capacities allocated to the heat source machines 5a and 5b matches the target capacity of 80% allocated to the heat source machine 5a before the rotation time t1. In this way, in the protection activation period (time t1 to t2), the target capacity of the heat source machines 5a and 5b is constant, and further, the sum of the target capacities of the heat source machines 5a and 5b is the target capacity of the heat source machine 5a before the rotation time t1. Accordingly, a reduction in the output capacity of the heat source system can be suppressed.
In addition, in the protection activation period, the heat source machine controllers 8a and 8b control the driving frequency of the compressors of the heat source machines 5a and 5b based on the target capacity allocated to each of the heat source machines 5a and 5b. As a result, as shown in Fig. 9, the output capacity of the heat source machine 5a decreases at a predetermined rate toward the target capacity of 55%, and the output capacity of the heat source machine 5b increases at a predetermined rate toward the target capacity of 25%.
After the time t2, that is, at the end of the protection activation period, the heat source machine controller 8a reduces the driving frequency of the heat source machine 5a at a constant change rate based on the stop command, and stops the heat source machine 5a.
In addition, after the time t2, the capacity allocation unit 43 allocates the target capacity of 80%, which is the target capacity of the heat source machine 5a before the rotation time t1, to the heat source machine 5b. As the target capacity of the heat source machine 5b increases, the heat source machine controller 8a increases the driving frequency of the heat source machine 5b at a constant change rate, and sets the output capacity of the heat source machine 5b to the target capacity of 80%.
The heat source machine controllers 8a and 8b may operate the heat source machines 5a and 5b such that the sum of the output capacities of the heat source machines 5a and 5b matches the required capacity of the usage-side unit in a period in which the output capacities of the heat source machines 5a and 5b change at a constant change rate.
Subsequently, at rotation time t3 at which a predetermined time has elapsed after the completion of the operation switching between the heat source machine 5a and the heat source machine 5b, the heat source machine controller 8a transmits the activation command to the heat source machine controller 8c, and the heat source machine controller 8c activates the heat source machine 5c, as in the case of the operation switching between the heat source machine 5a and the heat source machine 5b.
Regarding the rotation control after the time t3, the same operation as that between time t1 and t2 is performed on the heat source machine to be stopped and the heat source machine to be newly activated.
In this way, by providing the protection activation period in which both the heat source machine to be stopped and the heat source machine to be newly activated are operated at the time of switching the heat source machine in the rotation control, it is possible to reduce the output capacity deficiency of the heat source system at the time of the switching.
In addition, the rotation control updates the priority of the heat source machine 5 to be newly activated to the highest priority and updates the priority of the heat source machine to be stopped to the lowest priority at the time of switching the heat source machine 5. Accordingly, it is possible to reduce a deviation in the cumulative operation time of each heat source machine.
In the above-described embodiment, an example in which the heat source machine to be stopped and the heat source machine to be newly activated are one-to-one has been described. However, the heat source machine controller 8a may newly activate the plurality of heat source machines 5 via the respective heat source machine controllers 8 according to the required capacity of the usage-side unit.
In addition, the timing for starting the switching of the heat source machine may be when a certain time has elapsed after the heat source machine 5 is activated, or may be when the cumulative operation time of the heat source machine reaches a predetermined time.
In addition, in the protection activation period of the rotation control described above, when the target capacity of the heat source machine 5 before the protection activation period, that is, the required capacity of the usage-side unit, is lower than the total of the minimum capacity of the heat source machine 5 to be stopped and the minimum capacity of the heat source machine 5 to be newly activated, the heat source machine controller 8a operates the stop-side heat source machine and the activation-side heat source machine at their respective minimum capacities via each heat source machine controller 8. With such control, it is possible to suppress the output capacity of the heat source machine 5 from being deficient for the required capacity of the usage-side unit at the time of switching the heat source machine 5.
In addition, when the target capacity of the heat source machine 5 before the protection activation period, that is, the required capacity of the usage-side unit, is extremely low, for example, when the required capacity is equal to or less than the minimum capacity of the heat source machine 5 to be newly activated, the heat source machine 5 to be stopped may be stopped at the stage of the protection activation period. In this way, in a case where the minimum capacity of the heat source machine 5 to be newly activated is not deficient for the required capacity of the usage-side unit, the heat source machine to be stopped is stopped at the stage of the protection activation period, so that the energy efficiency can be improved.
As described above, according to the heat source system, the air-conditioning system, the control method, and the program according to the present embodiment, the controller 8 provides a protection activation period in which a first heat source machine 5b to be newly activated is operated at a fixed output and stopping a second heat source machine 5a to be switched after the protection activation period has elapsed, at the time of switching at which the heat source machine 5 to be operated is switched.
In this manner, in the protection activation period, a state where the first heat source machine and the second heat source machine are operated can be maintained. Therefore, it is possible to suppress a decrease in a cooling/heating capacity.
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.
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.
For example, in the above-described embodiment, the heat source machine controller 8a controls the activation and stop of the heat source machine 5 and allocates the target capacity. However, the present disclosure is not limited to this example. For example, instead of the heat source machine controller 8a, the system controller 10 may perform the control of the activation and stop of the heat source machine 5 and the allocation of the target capacity based on the calculated required load. That is, the system controller 10 may include the functions of the number-of-machines control unit 42 and the capacity allocation unit 43 shown in Fig. 6.
The heat source system, the air-conditioning system, the control method, and the 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 controller (8) that controls the number of the plurality of heat source machines in operation according to a required capacity required by the usage-side unit, in which the controller provides a protection activation period in which a first heat source machine (5b) to be newly activated is operated at a fixed output, and stops a second heat source machine (5a) to be switched after the protection activation period has elapsed, at the time of switching at which the heat source machine to be operated is switched.
According to the heat source system according to the present disclosure, in the protection activation period, a state where the first heat source machine and the second heat source machine are operated can be maintained. Therefore, it is possible to suppress a decrease in a cooling/heating capacity.
In a heat source system according to a second aspect of the present disclosure, in the first aspect, the controller may allocate a target capacity to each of the first heat source machine and the second heat source machine in the protection activation period such that a sum of target capacities allocated to the first heat source machine and the second heat source machine matches a target capacity allocated to the second heat source machine before the protection activation period.
According to the present aspect, the sum of the target capacities allocated to the first heat source machine and the second heat source machine in the protection activation period matches the target capacity allocated to the second heat source machine before the protection activation period. In this manner, it is possible to prevent a significant decrease in output when the heat source machine is switched.
In a heat source system according to a third aspect of the present disclosure, in the first aspect or the second aspect, the controller may allocate a minimum capacity, which is a minimum output capacity that the first heat source machine is capable of outputting, in the protection activation period.
According to the present aspect, the controller allocates the minimum capacity, which is the minimum output capacity that one heat source machine is capable of outputting, in the protection activation period. In this manner, the minimum output capacity is allocated to the first heat source machine, so that the remaining capacity can be covered by the unit to be stopped without impairing the required capacity.
A heat source system according to a fourth aspect of the present disclosure may, in the third aspect, in a case where a target capacity allocated to the second heat source machine before the protection activation period is equal to or less than a sum of minimum capacities of the first heat source machine and the second heat source machine, allocate the minimum capacities to the first heat source machine and to the second heat source machine, or allocate the minimum capacity to the heat source machine and stop the second heat source machine, in the protection activation period.
According to the present aspect, in a case where the output capacity of the heat source machine before the protection activation period is equal to or less than the sum of the minimum capacities of the first heat source machine and the second heat source machine, the minimum capacities are allocated to the first heat source machine and to the second heat source machine in the protection activation period. In this manner, it is possible to avoid a situation where a deficiency of output capacity occurs when switching the heat source machine. In addition, in a case where the output capacity allocated to the heat source machine before the protection activation period is a value close to the minimum capacity of the second heat source machine, even when the second heat source machine is stopped as it is, the output of the entire heat source system does not change much. Therefore, in such a case, the energy efficiency can be improved by stopping the second heat source machine.
A heat source system according to a fifth aspect of the present disclosure may include, in any one of the first aspect to the fourth aspect, 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, in which one of the heat source machine controllers may include the controller.
An air-conditioning system (1) according to a sixth aspect of the present disclosure includes, in any one of the first aspect to the fifth aspect, 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.
A control method for a heat source system (3) according to a seventh aspect of the present disclosure is a control method for a heat source system including a plurality of heat source machines (5) and supplying a heat medium to a usage-side unit (2), the method including: providing a protection activation period in which a first heat source machine to be newly activated is operated at a fixed output and stopping a second heat source machine to be switched after the protection activation period has elapsed, at the time of switching at which the heat source machine to be operated is switched.
A program according to an eighth aspect of the present disclosure is, in any one of the first aspect to the fifth aspect, a program for causing a computer to function as the controller.

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: Temperature sensor
29: Remote 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

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 plurality of heat source machines according to a required capacity required by the usage-side unit,

wherein the controller provides a protection activation period in which a first heat source machine to be newly activated is operated at a fixed output, and stops a second heat source machine to be switched after the protection activation period has elapsed, at the time of switching at which the heat source machine to be operated is switched.
The heat source system according to Claim 1,
wherein the controller allocates a target capacity to each of the first heat source machine and the second heat source machine in the protection activation period such that a sum of target capacities allocated to the first heat source machine and the second heat source machine matches a target capacity allocated to the second heat source machine before the protection activation period.
The heat source system according to Claim 1,
wherein the controller allocates a minimum capacity, which is a minimum output capacity that the first heat source machine is capable of outputting, in the protection activation period.
The heat source system according to Claim 3,
wherein in a case where a target capacity allocated to the second heat source machine before the protection activation period is equal to or less than a sum of minimum capacities of the first heat source machine and the second heat source machine, the controller allocates the minimum capacities to the first heat source machine and to the second heat source machine, or allocates the minimum capacity to the first heat source machine and stops the second heat source machine, in the protection activation period.
The heat source system according to Claim 1, 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 comprising:
providing a protection activation period in which a first heat source machine to be newly activated is operated at a fixed output and stopping a second heat source machine to be switched after the protection activation period has elapsed, at the time of switching at which the heat source machine to be operated is switched.
A program for causing a computer to function as the controller according to any one of Claims 1 to 5.