Control device, heat source system, control method, and control program

Abstract

To provide a control device, a heat source system, a control method, and a control program that can send out a heat medium at a required temperature more effectively.SOLUTION: A control device is applied to a heat source system 1 comprising a plurality of heat source machines 2a and 2b connected in series, and comprises a setting unit for setting outlet set temperatures of cold water in the respective heat source machines 2a and 2b on the basis of a measured value of a cold water flow rate, measured values of inlet temperatures of the cold water in the respective heat source machines 2a and 2b, and a required outlet temperature of the cold water in the heat source system 1.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] By connecting multiple heat source units in series, it is possible to supply cold water (heat medium) with a large temperature difference to the load side. For example, a heat source system equipped with two heat source units is disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6336295 Summary of the Invention [Problem to be solved by the invention]

[0004] In such a heat source system, the chilled water outlet set temperature of each heat source unit is determined according to the chilled water temperature state. However, for example, when the temperature of the chilled water flowing into the heat source system is high, the chilled water outlet set temperature of each heat source unit may be set high to prevent operation exceeding the capacity of each heat source unit.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a control device and heat source system, as well as a control method and control program, that can more effectively deliver a heat transfer medium at a required temperature. [Means for solving the problem]

[0006] A first aspect of the present disclosure is a control device applied to a heat source system including a plurality of heat source units connected in series, the control device including a setting unit that sets a heat medium outlet set temperature in each heat source unit based on a measured value of a heat medium flow rate, a measured value of a heat medium inlet temperature in each of the heat source units, and a required heat medium outlet temperature in the heat source system. and an update unit that compares an outlet setting temperature based on a heat medium flow rate set for the heat source unit on the most downstream side among the heat source units connected in series with a required outlet temperature, and updates the outlet setting temperature of the heat source unit on the most downstream side to the higher one; Equipped with The outlet set temperature is a set value of the heat medium temperature on the outlet side of each of the heat source units, and the requested outlet temperature is a heat medium temperature requested by the load side of the heat source system. It is a control device. Also, a control device applied to a heat source system having a plurality of heat source machines connected in series, the control device comprising: a setting unit that sets an outlet setting temperature of the heat medium in each heat source machine based on a measured value of a heat medium flow rate, a measured value of the heat medium inlet temperature in each of the heat source machines, and a required outlet temperature of the heat medium in the heat source system; and an updating unit that uses the outlet setting temperature of each of the heat source machines calculated based on the result of distributing the difference between the heat medium inlet temperature and the required outlet temperature of the heat medium in the heat source system in accordance with a rated capacity ratio of each of the heat source machines, and compares the outlet setting temperature based on the heat medium flow rate with the outlet setting temperature based on the rated capacity ratio in each of the heat source machines connected in series other than the heat source machine on the most downstream side, and updates the higher one as the outlet setting temperature of the heat source machine, wherein the outlet setting temperature is a setting value of the heat medium temperature on the outlet side of each of the heat source machines, and the required outlet temperature is a heat medium temperature requested by the load side of the heat source system.

[0007] A second aspect of the present disclosure is a control method for a heat source system having a plurality of heat source units connected in series, comprising the steps of: setting a heat medium outlet set temperature in each heat source unit based on a measured value of a heat medium flow rate, a measured value of a heat medium inlet temperature in each of the heat source units, and a required heat medium outlet temperature in the heat source system; and comparing an outlet setting temperature based on a heat medium flow rate set for the heat source unit on the most downstream side among the heat source units connected in series with a required outlet temperature, and updating the outlet setting temperature of the heat source unit on the most downstream side to the higher one; Have The outlet set temperature is a set value of the heat medium temperature on the outlet side of each of the heat source units, and the requested outlet temperature is a heat medium temperature requested by the load side of the heat source system. This is a control method. Also, a control method for a heat source system having a plurality of heat source machines connected in series, the control method includes the steps of: setting an outlet setting temperature of the heat medium in each heat source machine based on a measured value of the heat medium flow rate, a measured value of the heat medium inlet temperature in each of the heat source machines, and a required outlet temperature of the heat medium in the heat source system; and using the outlet setting temperature of each of the heat source machines calculated based on the result of distributing the difference between the heat medium inlet temperature and the required outlet temperature of the heat medium in the heat source system in accordance with the rated capacity ratio of each of the heat source machines, in each of the heat source machines connected in series other than the heat source machine on the most downstream side, comparing the outlet setting temperature based on the heat medium flow rate with the outlet setting temperature based on the rated capacity ratio, and updating the higher one as the outlet setting temperature of the heat source machine, wherein the outlet setting temperature is a setting value of the heat medium temperature on the outlet side of each of the heat source machines, and the required outlet temperature is a heat medium temperature required by the load side of the heat source system.

[0008] A third aspect of the present disclosure is a control program for a heat source system including a plurality of heat source units connected in series, the control program including a process for setting a heat medium outlet setting temperature in each heat source unit based on a measured value of a heat medium flow rate, a measured value of a heat medium inlet temperature in each of the heat source units, and a required heat medium outlet temperature in the heat source system. A process of comparing an outlet setting temperature based on a heat medium flow rate set for the heat source unit on the most downstream side among the heat source units connected in series with a required outlet temperature, and updating the outlet setting temperature of the heat source unit on the most downstream side to the higher one; Have your computer run The outlet set temperature is a set value of the heat medium temperature on the outlet side of each of the heat source units, and the requested outlet temperature is a heat medium temperature requested by the load side of the heat source system. This is a program. Also, a control program for a heat source system having a plurality of heat source machines connected in series, the control program causes a computer to execute the following processes: a process for setting an outlet setting temperature of the heat medium in each heat source machine based on a measured value of the heat medium flow rate, a measured value of the heat medium inlet temperature in each of the heat source machines, and a required outlet temperature of the heat medium in the heat source system; and a process for comparing an outlet setting temperature based on the heat medium flow rate with an outlet setting temperature based on the rated capacity ratio in each heat source machine other than the heat source machine on the most downstream side among the heat source machines connected in series, using the outlet setting temperature of each heat source machine calculated based on the result of distributing the difference between the heat medium inlet temperature and the required outlet temperature of the heat medium in the heat source system in accordance with the rated capacity ratio of each of the heat source machines, and updating the higher one as the outlet setting temperature of the heat source machine, wherein the outlet setting temperature is a setting value of the heat medium temperature on the outlet side of each of the heat source machines, and the required outlet temperature is a heat medium temperature requested by the load side of the heat source system. Effect of the Invention

[0009] According to the present disclosure, an effect is achieved in that a heat transfer medium at a required temperature can be more effectively delivered. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a schematic configuration of a heat source system according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a diagram illustrating an example of a hardware configuration of a control device according to an embodiment of the present disclosure. [Diagram 3]FIG. 2 is a functional block diagram illustrating functions of a control device according to an embodiment of the present disclosure. [Figure 4] 13 is a flowchart illustrating an example of a procedure for setting an outlet set temperature of a lower-side heat source unit according to an embodiment of the present disclosure. [Diagram 5] 10 is a flowchart illustrating an example of a procedure for setting an outlet set temperature of a higher-side heat source unit according to an embodiment of the present disclosure. [Figure 6] FIG. 13 is a diagram showing an effect of a setting process of an outlet set temperature of a control device according to an embodiment of the present disclosure. [Figure 7] 13A and 13B are diagrams illustrating the effect of a modified example of the outlet set temperature setting process of the control device according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of a control device, a heat source system, a control method, and a control program according to the present disclosure will be described with reference to the drawings. In this embodiment, a case where cold water is supplied to a load as a heat medium will be described, but hot water may be used as the heat medium.

[0012] FIG. 1 is a diagram showing a schematic configuration of a heat source system 1 according to this embodiment. As shown in FIG. 1, the heat source system 1 has a plurality of heat source units connected in series. In this embodiment, the heat source unit on the upstream side in the cold water flow is the upper heat source unit 2a, and the heat source unit on the downstream side is the lower heat source unit 2b. Here, two heat source units are illustrated, but the number of heat source units connected in series is not particularly limited. The heat source system 1 is provided with a cold water pump 5 for adjusting the flow rate of cold water supplied to the heat source units.

[0013] The upper heat source unit 2a and the lower heat source unit 2b are fixed-speed heat source units. The heat source unit is, for example, a heat pump type heat source unit, and examples thereof include a turbo chiller, an absorption chiller, and a heat recovery unit. The specifications of the heat source units are not limited to fixed speed. For example, as other specifications, the lower heat source unit 2b has a rated capacity of 2232.6 kW, a rated chilled water inlet temperature of 14.6°C, a rated chilled water outlet temperature of 5°C (temperature difference 9.6°C), and a rated chilled water flow rate of 200 m3 / h. The specifications of the upper heat source unit 2a are, for example, a rated capacity of 2418.6 kW, a rated chilled water inlet temperature of 25°C, a rated chilled water outlet temperature of 14.6°C (temperature difference 10.4°C), and a rated chilled water flow rate of 200 m3 / h. The above is an example of the specifications of the heat source units, and is not limited to the above specifications.

[0014] In the heat source system 1, the set value of the chilled water temperature (chilled water supply temperature) on the outlet side of the upper heat source unit 2a is called the outlet set temperature (upper SP) C2SP, and the set value of the chilled water temperature (chilled water supply temperature) on the outlet side of the lower heat source unit 2b is called the outlet set temperature (lower SP) C1SP. In other words, these set values ​​are target values. The chilled water supply temperature required by the load side is called the required outlet temperature (required SP).

[0015] In such a heat source system 1, cold water (e.g., 5°C to 30°C) that is warmed by use in an external load 4 such as a cooling device is supplied to the upper heat source unit 2a and the lower heat source unit 2b, where it is cooled to a predetermined required outlet temperature (e.g., 5°C). The cooled cold water is supplied to the external load 4 and returned to the heat source system 1 to be cooled again.

[0016] As shown in Fig. 1, the heat source system 1 is provided with a measuring instrument TE2 that measures the inlet temperature C2si of the chilled water in the upper heat source unit 2a and a measuring instrument TE1 that measures the inlet temperature C1si of the chilled water in the lower heat source unit 2b, and the measured values ​​are output to a control device 20 described later. The heat source system 1 is provided with a measuring instrument TE3 that measures the outlet temperature of the chilled water in the lower heat source unit 2b. A flow meter FT for measuring the chilled water flow rate (heat medium flow rate) C12sf is provided downstream of the lower heat source unit 2b (between the lower heat source unit 2b and the external load 4), and the measured value of the flow rate is output to a control device 20 described later. The installation position of the flow meter shown in Fig. 1 is an example, and it may be provided in another position.

[0017] The control device 20 controls the operation of the heat source system 1. Specifically, the control device 20 sets the outlet set temperature of each heat source device and controls each heat source device to send out chilled water at the outlet set temperature. When each heat source device is controlled based only on the temperature of the chilled water, if the temperature of the chilled water flowing into the heat source device is high, the heat source device may be operated so as not to overload. In such a case, sufficient cooling may not be performed, and the required outlet temperature may not be satisfied. However, depending on the flow rate of the chilled water flowing into the heat source device, it is expected that the required outlet temperature may be satisfied without overloading even if the temperature of the chilled water flowing into the heat source device is high. Therefore, the control device 20 controls each heat source device taking into account not only the temperature state of the chilled water but also the flow rate of the chilled water.

[0018] FIG. 2 is a diagram showing an example of a hardware configuration of the control device 20 according to the present embodiment. 2, the control device 20 is a computer system, and includes, for example, a CPU 11, a ROM (Read Only Memory) 12 for storing programs executed by the CPU 11, a RAM (Random Access Memory) 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 units are connected via a bus 18.

[0019] The control device 20 may include an input unit including a keyboard, a mouse, and the like, and a display unit including a liquid crystal display device or the like for displaying data.

[0020] The storage medium for storing the programs executed by the CPU 11 is not limited to the ROM 12. For example, it may be other auxiliary storage devices such as a magnetic disk, a magneto-optical disk, or a semiconductor memory.

[0021] A series of processing steps for realizing various functions described below are recorded in the form of a program on the hard disk drive 14, etc., and the CPU 11 reads this program into the RAM 13, etc., and executes information processing and arithmetic processing to realize various functions described below. The program may be installed in the ROM 12 or other storage medium in advance, may be provided in a state stored in a computer-readable storage medium, or may be distributed via wired or wireless communication means. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0022] Fig. 3 is a functional block diagram showing functions of the control device 20. As shown in Fig. 3, the control device 20 includes a setting unit 21, an update unit 22, and a control unit .

[0023] Setting unit 21 sets the chilled water outlet set temperature (C1SP, C2SP) in each heat source unit based on the measured chilled water flow rate, the measured chilled water inlet temperature in the heat source unit (C1si, C2si), and the required chilled water outlet temperature in heat source system 1. Specifically, setting unit 21 sets the outlet set temperature in each heat source unit such that the lower the measured chilled water flow rate, the lower the outlet set temperature in each heat source unit.

[0024] Specifically, the setting unit 21 sets the outlet set temperature of each heat source unit by multiplying the temperature difference between the rated inlet temperature and the rated outlet temperature of the heat source unit by a correction coefficient, which is the ratio of the rated value of the chilled water flow rate to the measured value of the chilled water flow rate, from the measured value of the inlet temperature.

[0025] The outlet set temperature C1SP of the lower heat source unit 2b is expressed by the following formula (1).

[0026] [Number 1] C1SP=C1si-(C1ci-C1co)×(C12cf / C12sf)×A1 (1)

[0027] In formula (1), C1SP is the outlet set 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) based on, for example, the specific gravity and specific heat or the deterioration of the heat source machine. For example, the coefficient may be changed when the specific gravity and specific heat change depending on the type of chilled water. In addition, for example, the coefficient may be changed when the rated capacity cannot be achieved due to the deterioration of the heat source machine. (C12cf / C12sf) is a correction coefficient based on the chilled water flow rate. A1 is basically 1. That is, if C1si and C12sf are measured, C1SP is calculated. For example, the required outlet temperature is used for C1co.

[0028] The outlet set temperature C2SP of the upper heat source unit 2a is expressed by the following formula (2).

[0029] [Number 2] C2SP=C2si-(C2ci-C2co)×(C12cf / C12sf)×A2 (2)

[0030] In formula (2), C2SP is the outlet set 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 the chilled water flow rate. A2 is basically 1. In other words, if C2si and C12sf are measured, C2SP can be calculated.

[0031] In this way, the outlet set temperature of the lower heat source unit 2b and the outlet set temperature of the upper heat source unit 2a are calculated taking into account the flow rate of chilled water. The method of setting the outlet set temperature taking into account the flow rate of chilled water is not limited to the above, as long as the outlet set temperature is set to be lower as the measured value of the chilled water flow rate is lower.

[0032] The update unit 22 updates the outlet setting temperature of each heat source unit. Specifically, the update unit 22 compares the outlet setting temperature based on the chilled water flow rate set for the most downstream heat source unit among the heat source units connected in series with the required outlet temperature, and updates the higher one as the outlet setting temperature of the most downstream heat source unit. In this embodiment, since two heat source units are connected in series, the most downstream heat source unit is the lower heat source unit 2b.

[0033] That is, the update unit 22 compares the outlet setting temperature C1SP of the lower-side heat source unit 2b calculated by formula (1) with the requested outlet temperature determined by the load side request, and updates the higher one as the outlet setting temperature of the lower-side heat source unit 2b.

[0034] The update unit 22 compares the outlet set temperature based on the chilled water flow rate with the outlet set temperature based on the rated capacity ratio in the heat source units other than the most downstream heat source unit among the heat source units connected in series, and updates the higher one as the outlet set temperature of the heat source unit. In this embodiment, since two heat source units are connected in series, the heat source unit other than the most downstream heat source unit is the upper heat source unit 2a.

[0035] That is, the update unit 22 compares the outlet setting temperature C2SP of the upper side heat source unit 2a calculated by formula (2) with the outlet setting temperature based on the rated capacity ratio, and updates the higher one as the outlet setting temperature of the upper side heat source unit 2a.

[0036] The outlet setting temperature based on the rated capacity ratio is a method of distributing load based on the capacity ratio corresponding to each heat source unit set in advance. Specifically, the outlet setting temperature of each heat source unit is calculated based on the result of distributing the 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 unit.

[0037] The outlet set temperature C2SPr of the upper-side heat source unit 2a based on the rated capacity ratio is expressed by the following formula (3).

[0038] [Number 3] C2SPr =C1co-(C2si-C1co)×[C1cc / (C1cc+C2cc)] (3)

[0039] In formula (3), C1cc teeth C1cc is the rated refrigeration capacity of the lower heat source unit, and C2cc is the rated refrigeration capacity of the upper heat source unit 2a. In other words, [C1cc / (C1cc+C2cc)] is the rated capacity ratio. In other words, if C2si is measured, C2SPr is calculated.

[0040] When C2SPr is calculated using equation (3), the update unit 22 compares the outlet setting temperature C2SP of the upper-side heat source unit 2a calculated using equation (2) with the outlet setting temperature C2SPr based on the rated capacity ratio calculated using equation (3), and updates the higher one as the outlet setting temperature of the upper-side heat source unit 2a.

[0041] It is also possible to perform control using the outlet set temperature of each heat source unit set by the setting unit 21 without providing the update unit 22.

[0042] The control unit 23 controls each heat source unit using the outlet setting temperature of each heat source unit set in the setting unit 21 and the update unit 22. Specifically, the lower heat source unit 2b is controlled to send out chilled water at the set outlet setting temperature. The upper heat source unit 2a is controlled to send out chilled water at the set outlet setting temperature. In this way, chilled water at a temperature that satisfies the outlet setting corresponding to the temperature of the inflowing chilled water is sent out.

[0043] Next, an example of the setting process of the outlet set temperature by the above-mentioned control device 20 will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a flowchart showing an example of the procedure of the setting process of the outlet set temperature of the lower heat source unit 2b. Fig. 5 is a flowchart showing an example of the procedure of the setting process of the outlet set temperature of the upper heat source unit 2a. The flows shown in Fig. 4 and Fig. 5 are repeatedly executed at a predetermined control period, for example, when the heat source system 1 is operating.

[0044] The process of setting the outlet set temperature of the lower heat source unit 2b will be described with reference to FIG.

[0045] First, each measurement value and rated specification information are acquired (S101). In S101, information for calculating formula (1) is acquired.

[0046] Next, the outlet set temperature of the lower heat source unit 2b is calculated (S102). In S102, the outlet set temperature is calculated using formula (1) and taking into account the flow rate of chilled water.

[0047] Next, it is determined whether the outlet temperature setting considering the flow rate of chilled water (the outlet temperature setting according to formula (1)) is greater than the requested outlet temperature (S103). If the outlet temperature setting considering the flow rate of chilled water is greater than the requested outlet temperature (YES in S103), the outlet temperature setting considering the flow rate of chilled water is used as the outlet temperature setting of the lower-side heat source unit 2b (S104).

[0048] If the outlet temperature setting taking into account the flow rate of chilled water is not higher than the requested outlet temperature (NO in S103), the requested outlet temperature is used as the outlet temperature setting of the lower heat source unit 2b (S105).

[0049] Next, the process of setting the outlet set temperature of the upper-side heat source unit 2a will be described with reference to FIG.

[0050] First, each measurement value and rated specification information are acquired (S201). In S201, information for calculating the formulas (2) and (3) is acquired.

[0051] Next, the outlet set temperature of the upper heat source unit 2a is calculated (S202). In S202, the outlet set temperature is calculated using formula (2) and taking into account the flow rate of the chilled water.

[0052] In parallel with S202, the outlet set temperature taking into consideration the rated capacity ratio is calculated using equation (3) (S203). The processes of S202 and S203 may be parallel processes or serial processes.

[0053] Next, it is determined whether the outlet set temperature taking into account the flow rate of chilled water (the outlet set temperature according to formula (2)) is greater than the outlet set temperature taking into account the rated capacity ratio (the outlet set temperature according to formula (3)) (S204). If the outlet set temperature taking into account the flow rate of chilled water is greater than the outlet set temperature taking into account the rated capacity ratio (YES determination in S204), the outlet set temperature taking into account the flow rate of chilled water is used as the outlet set temperature of the upper heat source unit 2a (S205).

[0054] If the outlet setting temperature taking into account the flow rate of chilled water is not greater than the outlet setting temperature taking into account the rated capacity ratio (NO judgment in S204), the outlet setting temperature taking into account the rated capacity ratio is used as the outlet setting temperature of the upper-side heat source unit 2a (S206).

[0055] In this manner, the outlet set temperature of the lower heat source unit 2b and the outlet set temperature of the upper heat source unit 2a are set, and each heat source unit is controlled based on the set outlet set temperature.

[0056] Next, the effect of the setting process of the outlet set temperature of the control device 20 described above will be described with reference to Fig. 6. In Fig. 6, the vertical axis represents the outlet set temperature of chilled water, and the horizontal axis represents the inlet temperature of chilled water (the temperature of chilled water flowing into the upper heat source unit 2a). The rated load means that the inlet temperature of chilled water reaches the rated inlet temperature of chilled water. In Fig. 6, it is assumed that the flow rate of chilled water is less than the rated flow rate of chilled water (for example, 180 m3 / h).

[0057] 6, the outlet setting temperature of the upper heat source unit 2a in this embodiment is shown as L2, and the outlet setting temperature of the lower heat source unit 2b is shown as L1. In addition, the outlet setting temperature of the upper heat source unit 2a in the reference example is shown as EX2, and the outlet setting temperature of the lower heat source unit 2b is shown as EX1.

[0058] The reference example is an example in which the outlet set temperature is set without considering the flow rate of chilled water. Specifically, in the reference example, when the load is up to the rated load (when the chilled water inlet temperature is lower than the rated chilled water inlet temperature), the outlet set temperature of the lower heat source unit 2b is set as the required outlet temperature, and the outlet set temperature of the upper heat source unit 2a is set according to the rated capacity ratio. In addition, in the reference example, when the load exceeds the rated load (when the chilled water inlet temperature is higher than the rated chilled water inlet temperature), the outlet set temperature is set assuming a value obtained by subtracting a predetermined value from the chilled water inlet temperature (for example, a value obtained by subtracting a rated chilled water inlet temperature difference) in order to prevent the capacity of the heat source unit from being exceeded.

[0059] As shown in FIG. 6, up to the rated load (the rated chilled water inlet temperature of the upper heat source unit 2a), L1, which is the outlet set temperature of the lower heat source unit 2b, and EX1 are equal. Specifically, in either case, the requested outlet temperature is set as the outlet set temperature. In the region exceeding the rated load, the outlet set temperature rises in EX1 of the reference example. On the other hand, in this embodiment, as shown as L1, the outlet set temperature is set taking into consideration that the chilled water flow rate is less than the rated chilled water flow rate, so that the requested outlet temperature is used as the outlet set temperature even after the rated load is exceeded. And even if the load further increases, the outlet set temperature is kept low. That is, in this embodiment, chilled water that satisfies the requested outlet temperature can be delivered in a wider load range. Even in the region of high load, the outlet set temperature can be set low. The lower the chilled water flow rate is compared to the rated chilled water flow rate, the greater the above effect.

[0060] For the upper heat source unit 2a, the outlet set temperature L2 and EX2 are almost equal up to the rated load (the rated chilled water inlet temperature of the upper heat source unit 2a). Specifically, in either case, in the region up to the rated load, the outlet set temperature is set with the same increasing tendency. In other words, in the region up to the rated load, the outlet set temperature based on the rated capacity ratio is applied. Then, in the region exceeding the rated load, the outlet set temperature rises in EX2 of the reference example. On the other hand, in this embodiment, as shown by L2, the outlet set temperature is set taking into consideration that the chilled water flow rate is less than the rated chilled water flow rate, so that the outlet set temperature is set with the same increasing tendency (i.e., the outlet set temperature based on the rated capacity ratio) as in the region up to the rated load even after the rated load is exceeded. And, even if the load further increases, the outlet set temperature is kept low. That is, in a wider load range, the load conditions of the upper heat source unit 2a and the lower heat source unit 2b are balanced, and high COP operation can be performed. And, even in the region where the load is high, the outlet set temperature can be set low. The lower the flow rate of the chilled water is compared to the rated flow rate of the chilled water, the greater the above effect.

[0061] 6, compared to the reference example, this embodiment can effectively satisfy the required outlet temperature over a wider load range (chilled water inlet temperature range). In addition, the operating conditions of the heat source units can be balanced over a wider range, enabling high COP operation.

[0062] FIG. 7 shows the characteristics of the above-mentioned reference example and the modified example of this embodiment, as in FIG. 6. In this embodiment, as shown in the flows of FIG. 4 and FIG. 5, the setting process is performed regardless of whether the inlet temperature of the chilled water is higher than the rated chilled water inlet temperature. The modified example of this embodiment is an example in which control switching is performed according to the relationship between the rated load and the load state. Specifically, in the modified example, when the load is up to the rated load (when the inlet temperature of the chilled water is lower than the rated chilled water inlet temperature), the outlet set temperature of the lower heat source unit 2b is set as the required outlet temperature, and the outlet set temperature of the upper heat source unit 2a is set according to the rated capacity ratio. In the modified example, when the load exceeds the rated load (when the inlet temperature of the chilled water is higher than the rated chilled water inlet temperature), the outlet set temperature of the lower heat source unit 2b is set according to formula (1), and the outlet set temperature of the upper heat source unit 2a is set according to formula (2). In FIG. 7, the outlet set temperature of the upper heat source unit 2a in the modified example is indicated as L2r, and the outlet set temperature of the lower heat source unit 2b is indicated as L1r.

[0063] When controlled as in the modified example, the lower heat source unit 2b uses the requested outlet temperature as the outlet set temperature up to approximately the rated load. Then, the setting method is switched in the region near the rated load, and the outlet set temperature is set by formula (1). Therefore, the outlet set temperature may temporarily drop near the rated load, and the outlet set temperature may fall below the requested outlet temperature. Then, up to approximately the rated load, the upper heat source unit 2a controls the outlet set temperature according to the rated capacity ratio, and the setting method is switched in the region near the rated load, and the outlet set temperature is set by formula (2). Therefore, the outlet set temperature may temporarily drop near the rated load, and the COP may drop.

[0064] For this reason, in the present invention, it is more preferable to carry out the processing according to the flows in Figures 4 and 5. However, it is also possible to carry out control according to the above-mentioned modified example.

[0065] As described above, according to the control device and heat source system, as well as the control method and control program of the present embodiment, in the heat source system 1 in which a plurality of heat source units are connected in series, the outlet temperature of each heat source unit is set using the measured value of the chilled water flow rate, the measured value of the chilled water inlet temperature of each heat source unit, and the required outlet temperature. This makes it possible to more effectively deliver chilled water at the required outlet temperature by taking the chilled water flow rate into consideration. For example, even if the chilled water inlet temperature of the heat source unit is high, if the chilled water flow rate is low, it is possible to deliver chilled water at the required outlet temperature within the capacity of the chiller.

[0066] The outlet set temperature based on the chilled water flow rate is compared with the required outlet temperature, and the higher is updated as the outlet set temperature of the heat source unit on the most downstream side, making it possible to more reliably send out chilled water at the required outlet temperature.The outlet set temperature based on the chilled water flow rate is compared with the outlet set temperature based on the rated capacity ratio, and the higher is updated as the outlet set temperature of the heat source unit, making it possible to operate at a high COP more effectively.

[0067] The present disclosure is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the invention.

[0068] The control device, heat source system, control method, and control program described in each of the above-described embodiments can be understood, for example, as follows. The control device (20) according to the present disclosure is applied to a heat source system (1) including a plurality of heat source units connected in series, and includes a setting unit (21) that sets a set outlet temperature of the heat medium in each heat source unit based on a measured value of the heat medium flow rate, a measured value of the inlet temperature of the heat medium in each of the heat source units, and a required outlet temperature of the heat medium in the heat source system (1). For example, the heat source units are an upper heat source unit 2a and a lower heat source unit 2b.

[0069] According to the control device (20) of the present disclosure, in a heat source system (1) in which a plurality of heat source units are connected in series, the outlet temperature of each heat source unit is set 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 unit, and the required outlet temperature. This makes it possible to more effectively send out the heat medium at the required outlet temperature by taking the heat medium flow rate into consideration. For example, even if the inlet temperature of the heat medium in the heat source unit is high, if the heat medium flow rate is low, it is possible to send out the heat medium at the required outlet temperature within the capacity of the chiller.

[0070] In the control device (20) according to the present disclosure, the setting unit (21) may set the outlet set temperature in each of the heat source units so that the outlet set temperature in each of the heat source units becomes lower as the measured value of the heat medium flow rate becomes lower.

[0071] According to the control device (20) of the present disclosure, even if the inlet temperature of the heat medium in the heat source unit is high, if the heat medium flow rate is low, it is possible to send out a heat medium with a lower temperature.

[0072] In the control device (20) according to the present disclosure, the setting unit (21) may set the outlet set temperature of each of the heat source units by multiplying the temperature difference between the rated inlet temperature and the rated outlet temperature of the heat source unit by a correction coefficient which is the ratio of the rated value of the heat medium flow rate to the measured value of the heat medium flow rate, from the measured value of the inlet temperature.

[0073] According to the control device (20) of the present disclosure, even if the inlet temperature of the heat medium in the heat source unit is high, if the heat medium flow rate is low, it is possible to deliver the heat medium at a lower temperature within the capacity of the chiller.

[0074] The control device (20) according to the present disclosure may include an update unit (22) that compares an outlet set temperature based on a heat medium flow rate set for the heat source unit furthest downstream among the heat source units connected in series with a required outlet temperature, and updates the outlet set temperature of the heat source unit furthest downstream to the higher one.

[0075] According to the control device (20) of the present disclosure, the outlet set temperature based on the heat medium flow rate is compared with the required outlet temperature, and the higher one is updated as the outlet set temperature of the heat source unit on the most downstream side, so that it is possible to more reliably deliver the heat medium at the required outlet temperature.

[0076] The control device (20) according to the present disclosure may be provided with an update unit (22) that uses the outlet setting temperature of each of the heat source units calculated based on the result of distributing the difference between the inlet temperature of the heat medium of the heat source system (1) and the required outlet temperature in accordance with the rated capacity ratio of each of the heat source units, and compares the outlet setting temperature based on the heat medium flow rate with the outlet setting temperature based on the rated capacity ratio in each of the heat source units connected in series other than the heat source unit furthest downstream, and updates the outlet setting temperature of the heat source unit to the higher one.

[0077] According to the control device (20) of the present disclosure, the outlet set temperature based on the heat medium flow rate and the outlet set temperature based on the rated capacity ratio are compared, and the higher one is updated as the outlet set temperature of the heat source unit, thereby making it possible to operate at a high COP more effectively.

[0078] The heat source system (1) according to the present disclosure includes a plurality of heat source units connected in series and the above-described control device (20).

[0079] The control method according to the present disclosure is a control method for a heat source system (1) having a plurality of heat source units connected in series, and includes a step of setting a heat medium outlet set temperature in each heat source unit based on a measured value of the heat medium flow rate, a measured value of the heat medium inlet temperature in each of the heat source units, and a required outlet temperature of the heat medium in the heat source system (1).

[0080] The control program of the present disclosure is a control program for a heat source system (1) having a plurality of heat source units connected in series, and causes a computer to execute a process of setting the outlet set temperature of the heat medium in each heat source unit based on the measured value of the heat medium flow rate, the measured value of the inlet temperature of the heat medium in each of the heat source units, and the required outlet temperature of the heat medium in the heat source system (1). [Explanation of symbols]

[0081] 1: Heat source system 2a:Upper side heat source machine 2b: Lower side heat source machine 4: External load 5: Chilled water pump 11: CPU 12: ROM 13: RAM 14: Hard disk drive 15: Communications Department 18: Bus 20: Control device 21: Setting section 22: Update section 23: Control section FT:Flowmeter TE1: Measuring instrument TE2: Measuring instrument TE3: Measuring Instrument

Claims

1. A control device applied to a heat source system having a plurality of heat source devices connected in series, A setting unit that sets a heat medium outlet set temperature in each heat source unit based on a measured value of a heat medium flow rate, a measured value of a heat medium inlet temperature in each heat source unit, and a required heat medium outlet temperature in the heat source system; An update unit that compares an outlet setting temperature based on a heat medium flow rate set for the heat source unit on the most downstream side among the heat source units connected in series with a required outlet temperature, and updates the outlet setting temperature of the heat source unit on the most downstream side to the higher one, The outlet set temperature is a set value of the heat medium temperature on the outlet side of each of the heat source units, A control device in which the requested outlet temperature is a heat medium temperature requested by a load side of the heat source system.

2. A control device applied to a heat source system having a plurality of heat source devices connected in series, A setting unit that sets a heat medium outlet set temperature in each heat source unit based on a measured value of a heat medium flow rate, a measured value of a heat medium inlet temperature in each heat source unit, and a required heat medium outlet temperature in the heat source system; An update unit uses the outlet setting temperature of each of the heat source units calculated based on the result of distributing the 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 of each of the heat source units, compares the outlet setting temperature based on the heat medium flow rate with the outlet setting temperature based on the rated capacity ratio in the heat source units other than the heat source unit on the most downstream side among the heat source units connected in series, and updates the outlet setting temperature of the heat source unit to the higher one, The outlet set temperature is a set value of the heat medium temperature on the outlet side of each of the heat source units, A control device in which the requested outlet temperature is a heat medium temperature requested by a load side of the heat source system.

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

4. A control device as described in any one of claims 1 to 3, wherein the setting unit sets the outlet set temperature of each of the heat source units by subtracting a value obtained by multiplying the temperature difference between the rated inlet temperature and the rated outlet temperature of the heat source unit by a correction coefficient which is the ratio of the rated value of the heat medium flow rate to the measured value of the heat medium flow rate from the measured value of the inlet temperature.

5. A plurality of heat source devices connected in series; A control device according to any one of claims 1 to 4; A heat source system comprising:

6. A control method for a heat source system having a plurality of heat source units connected in series, A step of setting an outlet set temperature of the heat medium in each heat source unit based on a measured value of the heat medium flow rate, a measured value of the inlet temperature of the heat medium in each of the heat source units, and a required outlet temperature of the heat medium in the heat source system; A process of comparing an outlet setting temperature based on a heat medium flow rate set for the heat source unit on the most downstream side among the heat source units connected in series with a required outlet temperature, and updating the outlet setting temperature of the heat source unit on the most downstream side to the higher one, The outlet set temperature is a set value of the heat medium temperature on the outlet side of each of the heat source units, A control method in which the requested outlet temperature is a heat medium temperature requested by a load side of the heat source system.

7. A control method for a heat source system having a plurality of heat source units connected in series, A step of setting an outlet set temperature of the heat medium in each heat source unit based on a measured value of the heat medium flow rate, a measured value of the inlet temperature of the heat medium in each of the heat source units, and a required outlet temperature of the heat medium in the heat source system; A process of comparing an outlet setting temperature based on a heat medium flow rate with an outlet setting temperature based on the rated capacity ratio in each of the heat source units other than the heat source unit on the most downstream side among the heat source units connected in series, using the outlet setting temperature of each of the heat source units calculated based on the result of distributing the difference between the inlet temperature of the heat medium of the heat source system and the required outlet temperature in accordance with the rated capacity ratio of each of the heat source units, and updating the outlet setting temperature of the heat source unit to the higher one, The outlet set temperature is a set value of the heat medium temperature on the outlet side of each of the heat source units, A control method in which the requested outlet temperature is a heat medium temperature requested by a load side of the heat source system.

8. A control program for a heat source system having a plurality of heat source units connected in series, A process of setting a heat medium outlet set temperature in each heat source machine based on a measured value of a heat medium flow rate, a measured value of a heat medium inlet temperature in each of the heat source machines, and a required heat medium outlet temperature in the heat source system; a process of comparing an outlet setting temperature based on a heat medium flow rate set for the heat source unit on the most downstream side among the heat source units connected in series with a required outlet temperature, and updating the outlet setting temperature of the heat source unit on the most downstream side to the higher one; The outlet set temperature is a set value of the heat medium temperature on the outlet side of each of the heat source units, A control program in which the requested outlet temperature is a heat medium temperature requested by a load side of the heat source system.

9. A control program for a heat source system having a plurality of heat source units connected in series, A process of setting a heat medium outlet set temperature in each heat source machine based on a measured value of a heat medium flow rate, a measured value of a heat medium inlet temperature in each of the heat source machines, and a required heat medium outlet temperature in the heat source system; using the outlet setting temperature of each of the heat source units calculated based on the result of distributing the difference between the inlet temperature of the heat medium of the heat source system and the required outlet temperature in accordance with the rated capacity ratio of each of the heat source units, in each of the heat source units connected in series other than the heat source unit on the most downstream side, 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 one is updated as the outlet setting temperature of the heat source unit; The outlet set temperature is a set value of the heat medium temperature on the outlet side of each of the heat source units, A control program in which the requested outlet temperature is a heat medium temperature requested by a load side of the heat source system.

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