CONTROL DEVICE, HEAT SOURCE SYSTEM, CONTROL METHOD, AND CONTROL PROGRAM

Abstract

The purpose of the present invention is to provide a control device, a heat source system, a control method, and a control program with which a heat medium at a required temperature can be more effectively sent out. This control device, which is applied to a heat source system 1 comprising a plurality of heat source machines (2a), (2b) connected in series, comprises a setting unit which sets the outlet setting temperatures of cool water in the respective heat source machines (2a), (2b) on the basis of: a measured value of a cool water flow rate, measured values of inlet temperatures of the cool water in the respective heat source machines (2a), (2b); and the required outlet temperature of the cool water in the heat source system (1).

Description

TECHNICAL FIELD

The present disclosure relates to a control device, a heat source system, a control method, and a control program.

BACKGROUND ART

By connecting a plurality of heat source machines in series, chilled water (heat medium) having a large temperature difference can be discharged to a load side. For example, a heat source system including two heat source machines is disclosed in PTL 1.

CITATION LIST

Patent Literature

• [PTL 1] Japanese Patent No. 6336295

SUMMARY OF INVENTION

Technical Problem

In such a heat source system, an outlet setting temperature of the chilled water of each heat source machine is determined according to a temperature state of the chilled water. However, for example, in a case where the temperature of the chilled water flowing into the heat source system is high, the outlet setting temperature of the chilled water of each heat source machine may be set high in order to prevent an operation exceeding the capacity of each heat source machine.

The present disclosure has been made in view of such circumstances, and an object thereof is to provide a control device, a heat source system, a control method, and a control program capable of more effectively discharging a heat medium having a required temperature.

Solution to Problem

According to a first aspect of the present disclosure, there is provided a control device applied to a heat source system including a plurality of heat source machines connected in series, the control device including a setting unit that sets an outlet setting temperature of a heat medium in each of the heat source machines on the basis of a measured value of a heat medium flow rate, a measured value of an inlet temperature of the heat medium in the heat source machine, and a required outlet temperature of the heat medium in the heat source system.

According to a second aspect of the present disclosure, there is provided a control method for a heat source system including a plurality of heat source machines connected in series, the control method including a step of setting an outlet setting temperature of a heat medium in each of the heat source machines on the basis of a measured value of a heat medium flow rate, a measured value of an inlet temperature of the heat medium in the heat source machine, and a required outlet temperature of the heat medium in the heat source system.

According to a third aspect of the present disclosure, there is provided a control program for a heat source system including a plurality of heat source machines connected in series, the control program causing a computer to execute a process of setting an outlet setting temperature of a heat medium in each of the heat source machines on the basis of a measured value of a heat medium flow rate, a measured value of an inlet temperature of the heat medium in the heat source machine, and a required outlet temperature of the heat medium in the heat source system.

Advantageous Effects of Invention

According to the present disclosure, it is possible to achieve an effect of being capable of more effectively discharging a heat medium having a required temperature.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a schematic configuration of a heat source system according to an embodiment of the present disclosure.

FIG. 2 is a diagram illustrating an example of a hardware configuration of a control device according to an embodiment of the present disclosure.

FIG. 3 is a functional block diagram illustrating functions of the control device according to the embodiment of the present disclosure.

FIG. 4 is a flowchart illustrating an example of a procedure of a process of setting an outlet setting temperature of a lower-level side heat source machine according to the embodiment of the present disclosure.

FIG. 5 is a flowchart illustrating an example of a procedure of a process of setting an outlet setting temperature of a higher-level side heat source machine according to the embodiment of the present disclosure.

FIG. 6 is a diagram illustrating an effect of a process of setting an outlet setting temperature in the control device according to the embodiment of the present disclosure.

FIG. 7 is a diagram illustrating an effect of a modification example in the process of setting an outlet setting temperature in the control device according to the embodiment of the present disclosure.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a control device, a heat source system, a control method, and a control program according to an embodiment of the present disclosure will be described with reference to the drawings. In the present embodiment, a case where chilled water is supplied to a load as a heat medium will be described. However, hot water may be used as a heat medium.

FIG. 1 is a diagram illustrating a schematic configuration of a heat source system 1 according to the present embodiment. As illustrated in FIG. 1, the heat source system 1 includes a plurality of heat source machines connected in series. In the present embodiment, an upstream heat source machine in a chilled water flow will be referred to as a higher-level side heat source machine 2a, and a downstream heat source machine will be referred to as a lower-level side heat source machine 2b. Although two heat source machines are illustrated here, the number of heat source machines connected in series is not particularly limited. The heat source system 1 is provided with a chilled water pump 5 for adjusting a flow rate of chilled water supplied to the heat source machine.

The higher-level side heat source machine 2a and the lower-level side heat source machine 2b are fixed-velocity heat source machines. The heat source machine is, for example, a heat pump type heat source machine, and examples thereof include a centrifugal chiller, an absorption type chiller, and a heat recovery machine. Specifications of the heat source machine are not limited to the fixed velocity. For example, as other specifications, the lower-level side heat source machine 2b has a rated capacity of 2232.6 kW, a rated chilled water inlet temperature of 14.6° C., and a rated chilled water outlet temperature of 5° C. (temperature difference of 9.6° C.), and a rated chilled water flow rate of 200 m3/h. Regarding the specifications of the higher-level side heat source machine 2a, for example, a rated capacity is 2418.6 kW, a rated chilled water inlet temperature is 25° C., a rated chilled water outlet temperature is 14.6° C. (temperature difference 10.4° C.), and a rated chilled water flow rate is 200 m3/h. The above specifications of the heat source machine are examples, and the present disclosure is not limited to the above specifications.

In the heat source system 1, a setting value of an outlet side chilled water temperature (chilled water supply temperature) of the higher-level side heat source machine 2a will be referred to as an outlet setting temperature (higher-level SP) C2SP, and a setting value of an outlet side chilled water temperature (chilled water supply temperature) of the lower-level side heat source machine 2b will be referred to as an outlet setting temperature (lower-level SP) C1SP. In other words, these setting values are target values. The chilled water supply temperature required from a load side will be referred to as a required outlet temperature (required SP).

In such a heat source system 1, chilled water (for example, 5° C. to 30° C.) warmed by being used by an external load 4 such as a cooling device is supplied to the higher-level side heat source machine 2a and the lower-level side heat source machine 2b and is cooled to a predetermined required outlet temperature (for example, 5° C.). The cooled chilled water is supplied to the external load 4, returned to the heat source system 1, and is cooled.

As illustrated in FIG. 1, the heat source system 1 is provided with measurement equipment TE2 that measures an inlet temperature C2si of chilled water in the higher-level side heat source machine 2a and measurement equipment TE1 that measures an inlet temperature C1si of chilled water in the lower-level side heat source machine 2b. Measured values are output to a control device 20 that will be described later. The heat source system 1 is provided with measurement equipment TE3 that measures an outlet temperature of chilled water in the lower-level side heat source machine 2b. A flow meter FT for measuring a chilled water flow rate (heat medium flow rate) C12sf is provided on the downstream side of the lower-level side heat source machine 2b (between the lower-level side heat source machine 2b and the external load 4), and a measured value of the flow rate is output to the control device 20 that will be described later. FIG. 1 illustrates an example of an installation position of the flow meter, and the flow meter may be installed at another position.

The control device 20 controls an operation of the heat source system 1. Specifically, each heat source machine is controlled such that an outlet setting temperature of each heat source machine is set and chilled water having the outlet setting temperature is discharged. In a case where each heat source machine is controlled on the basis of only the temperature of the chilled water, if the temperature of the chilled water flowing into the heat source machine is high, the heat source machine may be operated not to be overloaded. In such a case, sufficient cooling may not be performed, and a required outlet temperature may not be satisfied. However, depending on a flow rate of chilled water flowing into the heat source machine, there is a possibility that a required outlet temperature can be satisfied without being overloaded even if the temperature of the chilled water flowing into the heat source machine is high. Therefore, the control device 20 controls each heat source machine in consideration of not only a temperature state of the chilled water but also a flow rate of the chilled water.

FIG. 2 is a diagram illustrating an example of a hardware configuration of the control device 20 according to the present embodiment.

As illustrated in FIG. 2, the control device 20 is a computer system, and includes, for example, a CPU 11, a read only memory (ROM) 12 that stores a program or the like executed by the CPU 11, a random access memory (RAM) 13 that functions as a work area when each program is executed, a hard disk drive (HDD) 14 as a large-capacity storage device, and a communication unit 15 for connecting to a network or the like. A solid state drive (SSD) may be used as the large-capacity storage device. These constituents are connected via a bus 18.

The control device 20 may include an input unit including a keyboard, a mouse, or the like, a display unit including a liquid crystal display device for displaying data, and the like.

A storage medium for storing a program or the like executed by the CPU 11 is not limited to the ROM 12. For example, other auxiliary storage devices such as a magnetic disk, a magnetooptical disk, and a semiconductor memory may be used.

A series of processing processes for realizing various functions to be described later is recorded in the hard disk drive 14 or the like in the form of a program, and the CPU 11 reads the program into the RAM 13 or the like to execute a process of processing and calculating information. As a result, various functions that will be described later are realized. The program may employ a form in which the program is installed in the ROM 12 or other storage medium in advance, a form in which the program is provided in a state of being stored in a computer-readable storage medium, or a form in which the program is distributed via wired or wireless communication means. The computer-readable storage medium is a magnetic disk, an magnetooptical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like.

FIG. 3 is a functional block diagram illustrating the functions of the control device 20. As illustrated in FIG. 3, the control device 20 includes a setting unit 21, an update unit 22, and a control unit 23.

The setting unit 21 sets the outlet setting temperatures (C1SP and C2SP) of chilled water in the respective heat source machines on the basis of a measured value of a chilled water flow rate, measured values of inlet temperatures (C1si and C2si) of the chilled water in the heat source machines, and a required outlet temperature of the chilled water in the heat source system 1. Specifically, the setting unit 21 sets the outlet setting temperature in each heat source machine such that the lower the measured value of the chilled water flow rate, the lower the outlet setting temperature in each heat source machine.

Specifically, the setting unit 21 calculates a value obtained by multiplying a temperature difference between the rated inlet temperature and the rated outlet temperature of the heat source machine by a correction coefficient that is a ratio of the rated value of the chilled water flow rate to the measured value of the chilled water flow rate, and sets the outlet setting temperature of each heat source machine by subtracting the calculated value from the measured value of the inlet temperature.

The outlet setting temperature C1SP of the lower-level side heat source machine 2b is represented by the following Equation (1).

[Math. 1]

C1SP=C1si−(C1ci−C1co)×(C12cf/C12sf)×A1  (1)

In Equation (1), C1SP is the outlet setting temperature, C1si is the inlet temperature (measured value), C1ci is the rated inlet temperature, C1co is the rated outlet temperature, C12sf is the chilled water flow rate (measured value), C12cf is the rated chilled water flow rate, and A1 is an adjustment parameter (coefficient). The coefficient may be set (changed), for example, on the basis of the specific gravity/specific heat or the deterioration of the heat source machine. For example, the coefficient may be changed when the specific gravity and the specific heat change depending on the type of chilled water. For example, the coefficient may be changed when the rated capacity cannot be obtained due to deterioration of the heat source machine. (C12cf/C12sf) is a correction coefficient based on a flow rate of chilled water. A1 is basically 1. That is, when C1si and C12sf are measured, C1SP is calculated. For C1co, for example, the required outlet temperature is used.

The outlet setting temperature C2SP of the higher-level side heat source machine 2a is represented by the following Equation (2).

[Math. 2]

C2SP=C2si−(C2ci−C2co)×(C12cf/C12sf)×A2  (2)

In Equation (2), C2SP is the outlet setting temperature, C2si is the inlet temperature (measured value), C2ci is the rated inlet temperature, C2co is the rated outlet temperature, C12sf is the chilled water flow rate (measured value), C12cf is the rated chilled water flow rate, and A2 is an adjustment parameter (coefficient). (C12cf/C12sf) is a correction coefficient based on a flow rate of chilled water. A2 is basically 1. That is, when C2si and C12sf are measured, C2SP is calculated.

As described above, the outlet setting temperature of the lower-level side heat source machine 2b and the outlet setting temperature of the higher-level side heat source machine 2a are calculated in consideration of the flow rate of the chilled water. A method of setting the outlet setting temperature in consideration of the flow rate of the chilled water is not limited to the above method as long as the outlet setting temperature is set to become lower as the measured value of the chilled water flow rate become lower.

The update unit 22 updates the outlet setting temperature of each heat source machine. Specifically, the update unit 22 compares the outlet setting temperature based on a chilled water flow rate set for the heat source machine on the most downstream side among the heat source machines connected in series with the required outlet temperature, and updates a higher temperature as the outlet setting temperature of the heat source machine on the most downstream side. In the present embodiment, since the two heat source machines are connected in series, the heat source machine on the most downstream side is the lower-level side heat source machine 2b.

That is, the update unit 22 compares the outlet setting temperature C1SP of the lower-level side heat source machine 2b calculated according to Equation (1) with a required outlet temperature determined according to a request from the load side, and updates a higher temperature as the outlet setting temperature of the lower-level side heat source machine 2b.

In a heat source machine other than the heat source machine on the most downstream side among the heat source machines connected in series, the update unit 22 compares an outlet setting temperature based on a chilled water flow rate with an outlet setting temperature based on a rated capacity ratio, and updates a higher temperature as the outlet setting temperature of the heat source machine. In the present embodiment, since the two heat source machines are connected in series, the heat source machine other than the heat source machine on the most downstream side is the higher-level side heat source machine 2a.

That is, the update unit 22 compares the outlet setting temperature C2SP of the higher-level side heat source machine 2a calculated according to Equation (2) with the outlet setting temperature based on the rated capacity ratio, and updates a higher temperature as the outlet setting temperature of the higher-level side heat source machine 2a.

The outlet setting temperature based on the rated capacity ratio is calculated according to a temperature of performing load distribution on the basis of a preset capacity ratio corresponding to each heat source machine. Specifically, the outlet setting temperature of each heat source machine is calculated on the basis of a result of distributing a difference between the inlet temperature of the chilled water of the heat source system 1 and the required outlet temperature according to the rated capacity ratio of each heat source machine.

The outlet setting temperature C2SPr of the higher-level side heat source machine 2a based on the rated capacity ratio is represented by the following Equation (3).

[Math. 3]

C2SPr=C1co−(C2si−C1co)×[C1cc/(C1cc+C2cc)]   (3)

In Equation (3), C1cc is the rated cooling capacity of the lower-level side heat source machine, and C2cc is the rated cooling capacity of the higher-level side heat source machine 2a. That is, [C1cc/(C1cc+C2cc)] is the rated capacity ratio. That is, when C2si is measured, C2SPr is calculated.

When C2SPr is calculated according to Equation (3), the update unit 22 compares the outlet setting temperature C2SP of the higher-level side heat source machine 2a calculated according to Equation (2) with the outlet setting temperature C2SPr based on the rated capacity ratio calculated according to Equation (3), and updates a higher temperature as the outlet setting temperature of the higher-level side heat source machine 2a.

The control may be executed by using the outlet setting temperature of each heat source machine set by the setting unit 21 without providing the update unit 22.

The control unit 23 controls each heat source machine by using the outlet setting temperature of each heat source machine set in the setting unit 21 and the update unit 22. Specifically, the lower-level side heat source machine 2b is controlled to discharge the chilled water having the set outlet setting temperature. The higher-level side heat source machine 2a is controlled to discharge the chilled water having the set outlet setting temperature. As described above, the chilled water having a temperature that satisfies the outlet setting corresponding to the temperature of the inflowing chilled water is discharged.

Next, an example of a process of setting an outlet setting temperature in the control device 20 will be described with reference to FIGS. 4 and 5. FIG. 4 is a flowchart illustrating an example of a procedure of setting an outlet setting temperature of the lower-level side heat source machine 2b. FIG. 5 is a flowchart illustrating an example of a procedure of setting the outlet setting temperature of the higher-level side heat source machine 2a. The flows illustrated in FIGS. 4 and 5 are repeatedly executed at a predetermined control cycle, for example, in a case where the heat source system 1 is operating.

The process of setting an outlet setting temperature of the lower-level side heat source machine 2b will be described with reference to FIG. 4.

First, each measured value and rated specification information are acquired (S101). In S101, information for computing Equation (1) is acquired.

Next, an outlet setting temperature of the lower-level side heat source machine 2b is calculated (S102). In S102, the outlet setting temperature is calculated in consideration of the flow rate of the chilled water by using Equation (1).

Next, it is determined whether or not the outlet setting temperature (the outlet setting temperature according to Equation (1)) in consideration of the flow rate of the chilled water is higher than a required outlet temperature (S103). In a case where the outlet setting temperature in consideration of the flow rate of the chilled water is higher than the required outlet temperature (determination in S103 is YES), the outlet setting temperature in consideration of the flow rate of the chilled water is used as the outlet setting temperature of the lower-level side heat source machine 2b (S104).

In a case where the outlet setting temperature in consideration of the flow rate of the chilled water is not higher than the required outlet temperature (determination in S103 is NO), the required outlet temperature is used as the outlet setting temperature of the lower-level side heat source machine 2b (S105).

Next, a process of setting an outlet setting temperature of the higher-level side heat source machine 2a will be described with reference to FIG. 5.

First, each measured value and rated specification information are acquired (S201). In S201, information for computing Equation (2) and Equation (3) is acquired.

Next, an outlet setting temperature of the higher-level side heat source machine 2a is calculated (S202). In S202, the outlet setting temperature is calculated in consideration of the flow rate of the chilled water by using Equation (2).

In parallel to S202, an outlet setting temperature in consideration of the rated capacity ratio is calculated by using Equation (3) (S203). The processes in S202 and S203 may be executed in parallel or in series.

Next, it is determined whether or not the outlet setting temperature (outlet setting temperature according to Equation (2)) in consideration of the flow rate of the chilled water is higher than the outlet setting temperature (outlet setting temperature according to Equation (3)) in consideration of the rated capacity ratio (S204). In a case where the outlet setting temperature in consideration of the flow rate of the chilled water is higher than the outlet setting temperature in consideration of the rated capacity ratio (determination in S204 is YES), the outlet setting temperature in consideration of the flow rate of the chilled water is used as the outlet setting temperature of the higher-level side heat source machine 2a (S205).

In a case where the outlet setting temperature in consideration of the flow rate of the chilled water is not higher than the outlet setting temperature in consideration of the rated capacity ratio (determination in S204 is NO), the outlet setting temperature in consideration of the rated capacity ratio is used as the outlet setting temperature of the higher-level side heat source machine 2a (S206).

As described above, the outlet setting temperature of the lower-level side heat source machine 2b and the outlet setting temperature of the higher-level side heat source machine 2a are set, and each heat source machine is controlled on the basis of the set outlet setting temperatures.

Next, an effect of the outlet setting temperature setting process performed by the above control device 20 will be described with reference to FIG. 6. In FIG. 6, a vertical axis represents an outlet setting temperature of chilled water, and a horizontal axis represents an inlet temperature of the chilled water (the temperature of the chilled water flowing into the higher-level side heat source machine 2a). The rated load means that the inlet temperature of the chilled water reaches the rated chilled water inlet temperature. In FIG. 6, it is assumed that a flow rate of the chilled water is lower than the rated chilled water flow rate (for example, 180 m3/h).

In FIG. 6, the outlet setting temperature of the higher-level side heat source machine 2a in the present embodiment is denoted by L2, and the outlet setting temperature of the lower-level side heat source machine 2b is denoted by L1. The outlet setting temperature of the higher-level side heat source machine 2a in a reference example is denoted by EX2, and the outlet setting temperature of the lower-level side heat source machine 2b is denoted by EX1.

The reference example is an example of a case where the outlet setting temperature is set without considering the flow rate of the chilled water. Specifically, in the reference example, in a case of up to the rated load (in a case where the inlet temperature of the chilled water is lower than the rated chilled water inlet temperature), an outlet side setting temperature of the lower-level side heat source machine 2b is set to the required outlet temperature, and an outlet side setting temperature of the higher-level side heat source machine 2a is set according to the rated capacity ratio. The reference example is a case where a value obtained by subtracting the inlet temperature of the chilled water by a predetermined value (for example, a value obtained by subtracting the rated chilled water inlet temperature difference) is assumed and set as the outlet setting temperature in order to prevent the capacity of the heat source machine from being exceeded in a case where the rated load is exceeded (in a case where the inlet temperature of the chilled water is higher than the rated chilled water inlet temperature).

As illustrated in FIG. 6, up to the rated load (the rated chilled water inlet temperature of the higher-level side heat source machine 2a), L1 and EX1 which are the outlet setting temperatures of the lower-level side heat source machine 2b are the same. Specifically, in any case, the required outlet temperature is set as the outlet setting temperature. In a region where the rated load is exceeded, the outlet setting temperature rises in EX1 of the reference example. On the other hand, in the present embodiment, as denoted by L1, the outlet setting temperature is set in consideration of the fact that the chilled water flow rate is lower than the rated chilled water flow rate. Therefore, even after the rated load is exceeded, the required outlet temperature is used as the outlet setting temperature. Even if the load further increases, the outlet setting temperature is kept low. That is, in the present embodiment, the chilled water satisfying the required outlet temperature can be discharged in a wider load range. Even in a region where the load is high, the outlet setting temperature can be set low. As the flow rate of the chilled water becomes lower than the rated chilled water flow rate, the above effect becomes greater.

Regarding the higher-level side heat source machine 2a, up to the rated load (the rated chilled water inlet temperature of the higher-level side heat source machine 2a), the outlet setting temperatures L2 and EX2 are substantially the same. Specifically, in any case, in the region up to the rated load, the outlet setting temperature is set with the same increasing tendency. In other words, in a region up to the rated load, the outlet setting temperature based on the rated capacity ratio is applied. In a region where the rated load is exceeded, the outlet setting temperature rises in EX2 of the reference example. On the other hand, in the present embodiment, as denoted by L2, the outlet setting temperature is set in consideration of the fact that the flow rate of the chilled water is lower than the rated chilled water flow rate. Therefore, the outlet setting temperature is set in the same increasing tendency (that is, an outlet setting temperature based on the rated capacity ratio) as in the region up to the rated load even after the rated load is exceeded. Even if the load further increases, the outlet setting temperature is kept low. That is, in a wider load range, load states of the higher-level side heat source machine 2a and the lower-level side heat source machine 2b are balanced, and high COP operation can be performed. Even in a region where the load is high, the outlet setting temperature can be set low. As the flow rate of the chilled water becomes lower than the rated chilled water flow rate, the above effect becomes greater.

From FIG. 6, compared with the reference example, in the present embodiment, the required outlet temperature can be effectively satisfied in a wider load range (an inlet temperature range of chilled water). An operation state of each heat source machine can be balanced in a wider range, and a high COP operation becomes possible.

Similar to FIG. 6, FIG. 7 illustrates characteristics of the above-described reference example and a modification example of the present embodiment. In the present embodiment, as illustrated in the flows of FIGS. 4 and 5, the setting process is performed regardless of whether or not the inlet temperature of the chilled water is higher than the rated chilled water inlet temperature. The modification example of the present embodiment is an example in which control switching is performed depending on a relationship between a rated load and a load state. Specifically, in the modification example, in the case of up to the rated load (in a case where the inlet temperature of the chilled water is lower than the rated chilled water inlet temperature), an outlet side setting temperature of the lower-level side heat source machine 2b is set to the required outlet temperature, and an outlet side setting temperature of the higher-level side heat source machine 2a is set according to the rated capacity ratio. In the modification example, in a case where the rated load is exceeded (in a case where the inlet temperature of the chilled water is higher than the rated chilled water inlet temperature), the outlet side setting temperature of the lower-level side heat source machine 2b is set according to Equation (1), and the outlet side setting temperature of the higher-level side heat source machine 2a is set according to Equation (2). In FIG. 7, the outlet setting temperature of the higher-level side heat source machine 2a in the modification example is denoted by L2r, and the outlet setting temperature of the lower-level side heat source machine 2b is denoted by L1r.

In a case of control as in the modification example, the required outlet temperature is used as the outlet setting temperature in the lower-level side heat source machine 2b up to the rated load level. A setting method is changed in the region near the rated load, and the outlet setting temperature is set according to Equation (1). Thus, the outlet setting temperature may be temporarily lowered in the vicinity of the rated load, and the outlet setting temperature may fall below the required outlet temperature. Up to the rated load level, the outlet setting temperature of the higher-level side heat source machine 2a is controlled according to the rated capacity ratio, the setting method is changed in a region near the rated load, and the outlet setting temperature is set according to Equation (2). Thus, the outlet setting temperature may be temporarily lowered in the vicinity of the rated load and the COP may be lowered.

Therefore, in the invention of the present application, it is more preferable to perform processing as in the flows of FIGS. 4 and 5. However, control may be performed as in the above modification example.

As described above, according to the control device, the heat source system, the control method, and the control program related to the present embodiment, in the heat source system 1 in which a plurality of heat source machines are connected in series, an outlet temperature of each heat source machine is set by using a measured value of a chilled water flow rate, a measured value of an inlet temperature of chilled water of each heat source machine, and a required outlet temperature. Thus, it is possible to more effectively discharge the chilled water having the required outlet temperature in consideration of the chilled water flow rate. For example, even in a case where the inlet temperature of the chilled water in the heat source machine is high, if the chilled water flow rate is low, it is possible to discharge the chilled water having the required outlet temperature within the capacity of a chiller.

Since the outlet setting temperature based on the chilled water flow rate and the required outlet temperature are compared and a higher temperature is updated as the outlet setting temperature of the heat source machine on the most downstream side, it is possible to more reliably discharge the chilled water having the required outlet temperature. Since the outlet setting temperature based on the chilled water flow rate and the outlet setting temperature based on the rated capacity ratio are compared and a higher temperature is updated as the outlet setting temperature of the heat source machine, it is possible to more effectively perform an operation at a high COP.

The present disclosure is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.

The control device, the heat source system, the control method, and the control program described in each of the embodiments described above are understood as follows, for example.

The control device (20) according to the present disclosure is the control device (20) applied to the heat source system (1) including a plurality of heat source machines connected in series, and includes the setting unit (21) that sets an outlet setting temperature of a heat medium in each of the heat source machines on the basis of a measured value of a heat medium flow rate, a measured value of an inlet temperature of the heat medium in the heat source machine, and a required outlet temperature of the heat medium in the heat source system (1). For example, the heat source machines are the higher-level side heat source machine 2a and the lower-level side heat source machine 2b.

According to the control device (20) related to the present disclosure, in the heat source system (1) in which a plurality of heat source machines are connected in series, the outlet temperature of each heat source machine is set by using the measured value of the heat medium flow rate, the measured value of the inlet temperature of the heat medium of each heat source machine, and the required outlet temperature. Therefore, it is possible to more effectively discharge the heat medium having the required outlet temperature in consideration of the heat medium flow rate. For example, even in a case where the inlet temperature of the heat medium in the heat source machine is high, if the heat medium flow rate is low, it is possible to discharge the heat medium having the required outlet temperature within the capacity of a chiller.

In the control device (20) according to the present disclosure, the setting unit (21) may set the outlet setting temperature in each of the heat source machines such that the outlet setting temperature in each heat source machine becomes lower as the measured value of the heat medium flow rate becomes lower.

According to the control device (20) related to the present disclosure, even in a case where the inlet temperature of the heat medium in the heat source machine is high, if the heat medium flow rate is low, it is possible to discharge the heat medium having a lower temperature.

In the control device (20) according to the present disclosure, the setting unit (21) may calculate a value obtained by multiplying a temperature difference between a rated inlet temperature and a rated outlet temperature of the heat source machine by a correction coefficient that is a ratio of a rated value of the heat medium flow rate to the measured value of the heat medium flow rate, and set the outlet setting temperature of each heat source machine by subtracting the calculated value from the measured value of the inlet temperature.

According to the control device (20) related to the present disclosure, even in a case where the inlet temperature of the heat medium in the heat source machine is high, if the heat medium flow rate is low, it is possible to discharge the heat medium having a lower temperature within the capacity of a chiller.

The control device (20) related to the present disclosure may include the update unit (22) that compare an outlet setting temperature based on a heat medium flow rate set for a heat source machine on a most downstream side among the heat source machines connected in series with the required outlet temperature, and update a higher temperature as an outlet setting temperature of the heat source machine on the most downstream side.

According to the control device (20) related to the present disclosure, since the outlet setting temperature based on the heat medium flow rate and the required outlet temperature are compared, and the higher temperature is updated as the outlet setting temperature of the heat source machine on the most downstream side, it is possible to reliably discharge the heat medium having the required outlet temperature.

The control device (20) according to the present disclosure may include the update unit (22) that compares the outlet setting temperature based on the heat medium flow rate with the outlet setting temperature based on a rated capacity ratio of each heat source machine and updates a higher temperature as the outlet setting temperature of the heat source machine in heat source machines other than the heat source machine on the most downstream side among the heat source machines connected in series, by using the outlet setting temperature of each heat source machine calculated on the basis of a result of distributing a difference between the inlet temperature of the heat medium of the heat source system (1) and the required outlet temperature according to the rated capacity ratio.

According to the control device (20) related to the present disclosure, since the outlet setting temperature based on the heat medium flow rate is compared with the outlet setting temperature based on the rated capacity ratio, and the higher temperature is updated as the outlet setting temperature of the heat source machine, it is possible to more effectively perform an operation at a high COP.

The heat source system (1) according to the present disclosure includes a plurality of heat source machines connected in series, and the control device (20).

The control method according to the present disclosure is a control method for the heat source system (1) including a plurality of heat source machines connected in series, and includes a step of setting an outlet setting temperature of a heat medium in each of the heat source machines on the basis of a measured value of a heat medium flow rate, a measured value of an inlet temperature of the heat medium in the heat source machine, and a required outlet temperature of the heat medium in the heat source system (1).

A control program according to the present disclosure is a control program for the heat source system (1) including a plurality of heat source machines connected in series, and causes a computer to execute a process of setting an outlet setting temperature of a heat medium in each of the heat source machines on the basis of a measured value of a heat medium flow rate, a measured value of an inlet temperature of the heat medium in the heat source machine, and a required outlet temperature of the heat medium in the heat source system (1).

REFERENCE SIGNS LIST

• • 1: Heat source system
  • 2a: Higher-level side heat source machine
  • 2b: Lower-level side heat source machine
  • 4: External load
  • 5: Chilled water pump
  • 11: CPU
  • 12: ROM
  • 13: RAM
  • 14: Hard disk drive
  • 15: Communication unit
  • 18: Bus
  • 20: Control device
  • 21: Setting unit
  • 22: Update unit
  • 23: Control unit
  • FT: Flow meter
  • TE1: Measurement equipment
  • TE2: Measurement equipment
  • TE3: Measurement equipment

Claims

1. A control device applied to a heat source system including a plurality of heat source machines connected in series, the control device comprising:

a setting unit that sets an outlet setting temperature of a heat medium in each of the heat source machines on the basis of a measured value of a heat medium flow rate, a measured value of an inlet temperature of the heat medium in the heat source machine, and a required outlet temperature of the heat medium in the heat source system.

2. The control device according to claim 1, wherein the setting unit sets the outlet setting temperature in each of the heat source machines such that the outlet setting temperature in each of the heat source machines becomes lower as the measured value of the heat medium flow rate becomes lower.

3. The control device according to claim 1, wherein the setting unit calculates a value obtained by multiplying a temperature difference between a rated inlet temperature and a rated outlet temperature of the heat source machine by a correction coefficient that is a ratio of a rated value of the heat medium flow rate to the measured value of the heat medium flow rate, and sets the outlet setting temperature of each heat source machine by subtracting the calculated value from the measured value of the inlet temperature.

4. The control device according to claim 1, further comprising:

an update unit that compares an outlet setting temperature based on a heat medium flow rate set for a heat source machine on a most downstream side among the heat source machines connected in series with the required outlet temperature, and updates a higher temperature as an outlet setting temperature of the heat source machine on the most downstream side.

5. The control device according to claim 1, further comprising:

an update unit that compares the outlet setting temperature based on the heat medium flow rate with the outlet setting temperature based on a rated capacity ratio of each heat source machine and updates a higher temperature as the outlet setting temperature of the heat source machine in heat source machines other than a heat source machine on a most downstream side among the heat source machines connected in series, by using the outlet setting temperature of each heat source machine calculated on the basis of a result of distributing a difference between the inlet temperature of the heat medium of the heat source system and the required outlet temperature according to the rated capacity ratio.

6. A heat source system comprising:

a plurality of heat source machines connected in series; and

the control device according to claim 1.

7. A control method for a heat source system including a plurality of heat source machines connected in series, the control method comprising:

a step of setting an outlet setting temperature of a heat medium in each of the heat source machines on the basis of a measured value of a heat medium flow rate, a measured value of an inlet temperature of the heat medium in the heat source machine, and a required outlet temperature of the heat medium in the heat source system.

8. A control program for a heat source system including a plurality of heat source machines connected in series, the control program causing a computer to execute:

a process of setting an outlet setting temperature of a heat medium in each of the heat source machines on the basis of a measured value of a heat medium flow rate, a measured value of an inlet temperature of the heat medium in the heat source machine, and a required outlet temperature of the heat medium in the heat source system.

9. The control device according to claim 2, wherein the setting unit calculates a value obtained by multiplying a temperature difference between a rated inlet temperature and a rated outlet temperature of the heat source machine by a correction coefficient that is a ratio of a rated value of the heat medium flow rate to the measured value of the heat medium flow rate, and sets the outlet setting temperature of each heat source machine by subtracting the calculated value from the measured value of the inlet temperature.

10. The control device according to claim 2, further comprising:

an update unit that compares an outlet setting temperature based on a heat medium flow rate set for a heat source machine on a most downstream side among the heat source machines connected in series with the required outlet temperature, and updates a higher temperature as an outlet setting temperature of the heat source machine on the most downstream side.

11. The control device according to claim 3, further comprising:

an update unit that compares an outlet setting temperature based on a heat medium flow rate set for a heat source machine on a most downstream side among the heat source machines connected in series with the required outlet temperature, and updates a higher temperature as an outlet setting temperature of the heat source machine on the most downstream side.

12. The control device according to claim 2, further comprising:

an update unit that compares the outlet setting temperature based on the heat medium flow rate with the outlet setting temperature based on a rated capacity ratio of each heat source machine and updates a higher temperature as the outlet setting temperature of the heat source machine in heat source machines other than a heat source machine on a most downstream side among the heat source machines connected in series, by using the outlet setting temperature of each heat source machine calculated on the basis of a result of distributing a difference between the inlet temperature of the heat medium of the heat source system and the required outlet temperature according to the rated capacity ratio.

13. The control device according to claim 3, further comprising:

an update unit that compares the outlet setting temperature based on the heat medium flow rate with the outlet setting temperature based on a rated capacity ratio of each heat source machine and updates a higher temperature as the outlet setting temperature of the heat source machine in heat source machines other than a heat source machine on a most downstream side among the heat source machines connected in series, by using the outlet setting temperature of each heat source machine calculated on the basis of a result of distributing a difference between the inlet temperature of the heat medium of the heat source system and the required outlet temperature according to the rated capacity ratio.

14. A heat source system comprising:

a plurality of heat source machines connected in series; and

the control device according to claim 2.

15. A heat source system comprising:

a plurality of heat source machines connected in series; and

the control device according to claim 3.

16. A heat source system comprising:

a plurality of heat source machines connected in series; and

the control device according to claim 4.

17. A heat source system comprising:

a plurality of heat source machines connected in series; and

the control device according to claim 5.