Make-up water supply system, control device, program, and make-up water supply method

Abstract

To suppress an electric power demand value of a building by controlling supply of makeup water to cooling water to be sent to a refrigeration machine.SOLUTION: A makeup water supply system 80 includes: a refrigeration machine 82 that cools a refrigerant sent from a heat use section 82A by exchanging heat with cooling water; a cooling tower 84 for cooling the cooling water sent from the refrigeration machine 82; a cooling water tank 86 for storing the cooling water sent from the cooling tower 84; a circulation pipe 88 for circulating the cooling water from the cooling water tank 86 to the refrigeration machine 82, from the refrigeration machine 82 to the cooling tower 84 and from the cooling tower 84 to the cooling water tank 86; a water supply mechanism 50 for supplying makeup water having a temperature lower than that of the cooling water to a water outlet 86B side of the cooling water tank 86; and a control device 10 that acquires an electric power demand value of a building and electric conductivity of the cooling water, and controls the water supply mechanism 50 on the basis of the acquired electric power demand value and electric conductivity.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present invention relates to a makeup water supply system, a control device, a program, and a makeup water supply method. [Background technology]

[0002] There has been a need for reducing the power demand value of buildings. One way to reduce the power demand value is to reduce the power consumption by reducing the output of air conditioners during times when the power demand value is expected to exceed the contracted power. However, there is a need for an air conditioning system that can reduce the power demand value without reducing the output of the air conditioners.

[0003] Therefore, Patent Document 1 below describes a turbo chiller that supplies clean water as spray water during blow operation, which discharges the spray water to be sprayed on the air heat exchanger. This makes it possible to replenish spray water with high cooling performance during blow operation. If the cooling performance of the chiller is improved in this way, it can also have the effect of suppressing power demand values. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-304126 Summary of the Invention [Problem to be solved by the invention]

[0005] In the turbo chiller of Patent Document 1, when the load is high and the outside air temperature is high, the concentration of spray water at which the blow operation starts is set low, increasing the frequency of the blow operation. This increases the cooling effect of the clean water. However, although the cooling effect of the chiller is improved, it is not controlled in relation to the power demand value. Therefore, there is a need for another method of suppressing the power demand value.

[0006] In consideration of the above, the present invention aims to suppress the power demand value of a building by controlling the supply of makeup water to the cooling water sent to the chiller. [Means for solving the problem]

[0007] The makeup water supply system of claim 1 includes a chiller that cools a refrigerant sent from a heat utilization unit by heat exchange with cooling water, a cooling tower that cools the cooling water sent from the chiller, a cooling water tank that stores the cooling water sent from the cooling tower, a circulation pipe that circulates the cooling water from the cooling water tank to the chiller, from the chiller to the cooling tower, and from the cooling tower to the cooling water tank, a water supply mechanism that supplies makeup water that is lower in temperature than the cooling water to the outlet side of the cooling water tank, and a control device that acquires a power demand value of a building and an electrical conductivity of the cooling water, and controls the water supply mechanism based on the acquired power demand value and electrical conductivity. Equipped with.

[0008] In the makeup water supply system of claim 1, the refrigerant sent from the heat utilization unit is cooled by the refrigerator, thereby making it possible to send the cooled refrigerant to the heat utilization unit.

[0009] The cooling water that has exchanged heat with the refrigerant is cooled in the cooling tower. As the cooling water evaporates in the cooling tower, the amount of cooling water in the system gradually decreases, but because the system is equipped with a cooling water tank, the amount of cooling water is greater than in systems without a cooling water tank.

[0010] This prevents the electrical conductivity from rising suddenly even if the cooling water evaporates. In addition, because the control device controls the water supply mechanism based on the electrical conductivity, make-up water can be supplied to lower the electrical conductivity when it becomes high.

[0011] The control device also controls the water supply mechanism based on the building's power demand value. When the power demand value increases, supplying makeup water that is lower in temperature than the cooling water can lower the temperature of the cooling water sent to the chiller. This reduces power consumption, thereby suppressing the power demand value.

[0012] In addition, the water supply mechanism is installed on the water outlet side of the cooling water tank. This allows the makeup water to be sent to the chiller before it is completely mixed with the cooling water in the cooling water tank. This allows for low-temperature cooling water to be sent to the chiller. This is highly effective in reducing power consumption.

[0013] In this way, in the makeup water supply system of claim 1, by controlling the supply of makeup water to the cooling water sent to the chiller, it is possible to adjust the electrical conductivity of the cooling water and suppress the power demand value.

[0014] The makeup water supply system of claim 2 is the makeup water supply system of claim 1, wherein the control device controls the water supply mechanism to supply the makeup water at least when the electrical conductivity is greater than a first predetermined value, and when the electrical conductivity is greater than a second predetermined value that is smaller than the first predetermined value and the power demand value is greater than a predetermined value.

[0015] In the makeup water supply system of claim 2, makeup water is supplied when the electrical conductivity is greater than a first predetermined value, thereby preventing the electrical conductivity from significantly exceeding the first predetermined value regardless of the power demand value.

[0016] Furthermore, when the electrical conductivity is greater than a second predetermined value that is smaller than the first predetermined value and the power demand is greater than a predetermined value, makeup water is supplied, thereby preventing the power demand from significantly exceeding the predetermined value when the electrical conductivity is greater than the second predetermined value.

[0017] A makeup water supply system according to a third aspect of the present invention is the makeup water supply system according to the first or second aspect, wherein a partition plate is provided between the water inlet and the water outlet in the cooling water tank.

[0018] In the makeup water supply system of claim 3, a partition plate is provided between the water inlet and the water outlet in the cooling water tank. This makes it difficult for makeup water supplied to the water outlet side in the cooling water tank to mix with water on the water inlet side. This makes it easier to supply cold water to the refrigerator.

[0019] The makeup water supply system of claim 4 is the makeup water supply system of any one of claims 1 to 3, further comprising a drainage mechanism that discharges the cooling water from the upstream side of the cooling tower in the circulation pipe, and the control device controls the drainage mechanism.

[0020] In the makeup water supply system of claim 4, the control device controls the drainage mechanism to discharge the cooling water. Because the drainage mechanism is provided upstream of the cooling tower, the cooling water discharged is the cooling water that has undergone heat exchange with the refrigerant in the chiller and has not yet been cooled in the cooling tower. In other words, the cooling water discharged is relatively hot within the system. This makes it easier to maintain a low temperature of the cooling water.

[0021] The makeup water supply system of claim 5 is the makeup water supply system according to any one of claims 1 to 3, wherein the control device acquires a water level in the cooling water tank and controls the water supply mechanism based on the acquired water level.

[0022] In the makeup water supply system of claim 5, the control device controls the water supply mechanism based on the water level in the cooling water tank. As a result, even if the supply of makeup water would be stopped under control based on the power demand value and electrical conductivity, makeup water is supplied when the water level falls below a lower limit, thereby preventing the system from running out of cooling water.

[0023] Furthermore, even when makeup water is supplied under control based on the power demand value and electrical conductivity, if the water level exceeds the upper limit, the supply of makeup water can be stopped to prevent cooling water from overflowing from the system.

[0024] The makeup water supply system of claim 6 is the makeup water supply system of claim 4, wherein the control device acquires the water level in the cooling water tank and controls the water supply mechanism and the drainage mechanism based on the acquired water level.

[0025] In the makeup water supply system of claim 6, the control device controls the water supply mechanism based on the water level in the cooling water tank. This makes it possible to prevent the system from running out of cooling water by supplying makeup water when the water level falls below a lower limit, even if the supply of makeup water would be stopped under control based on the power demand value and electrical conductivity.

[0026] Furthermore, even when makeup water is supplied under control based on the power demand value and electrical conductivity, if the water level exceeds the upper limit, the supply of makeup water can be stopped to prevent cooling water from overflowing from the system.

[0027] In this makeup water supply system, the control device controls the drainage mechanism based on the water level in the cooling water tank. This forces the water to be drained when the water level exceeds the upper limit, preventing the cooling water from overflowing from the system. When the water level falls below the lower limit, the drainage is stopped, preventing the cooling water from running out from the system.

[0028] The control device of claim 7 is arranged in a makeup water supply system including a chiller that cools refrigerant delivered from a heat utilization unit by exchanging heat with cooling water, a cooling tower that cools the cooling water delivered from the chiller, a cooling water tank that stores the cooling water delivered from the cooling tower, circulation pipes that circulate the cooling water from the cooling water tank to the chiller, from the chiller to the cooling tower, and from the cooling tower to the cooling water tank, and a water supply mechanism that supplies makeup water that is cooler than the cooling water to the outlet side of the cooling water tank, and has a processor, wherein the processor acquires a building's power demand value and the electrical conductivity of the cooling water, and controls the water supply mechanism based on the acquired power demand value and electrical conductivity.

[0029] The control device of claim 7 can achieve the same effects as the makeup water supply system of claim 1.

[0030] The program of claim 8 causes a computer to execute the following steps: acquiring a power demand value for a building; acquiring the electrical conductivity of the cooling water circulating among a chiller that cools the refrigerant delivered from a heat utilization unit by heat exchange with cooling water, a cooling tower that cools the cooling water delivered from the chiller, and a cooling water tank that stores the cooling water delivered from the cooling tower; and controlling a water supply mechanism that supplies blown makeup water to the outlet side of the cooling water tank based on the acquired power demand value and the electrical conductivity.

[0031] The program of claim 8 can achieve the same effect as the makeup water supply system of claim 1.

[0032] The makeup water supply method of claim 9 includes the steps of: acquiring a power demand value for a building; acquiring the electrical conductivity of the cooling water circulating among a chiller that cools a refrigerant delivered from a heat utilization unit by heat exchange with cooling water, a cooling tower that cools the cooling water delivered from the chiller, and a cooling water tank that stores the cooling water delivered from the cooling tower; and controlling a water supply mechanism that supplies blow makeup water to the outlet side of the cooling water tank based on the acquired power demand value and the electrical conductivity.

[0033] The makeup water supply method of claim 8 can achieve the same effects as the makeup water supply system of claim 1. [Effects of the Invention]

[0034] According to the present invention, the power demand value of a building can be suppressed by controlling the supply of makeup water to the cooling water sent to the chiller. [Brief explanation of the drawings]

[0035] [Figure 1A] 1 is a block diagram showing an outline of a makeup water supply system according to an embodiment of the present invention. [Figure 1B] 1 is a schematic diagram showing a water level meter applied to a makeup water supply system according to an embodiment of the present invention. [Figure 2] 2 is a block diagram showing the electrical configuration of a control device applied to the makeup water supply system according to the embodiment of the present invention. FIG [Figure 3] 1 is a functional block diagram showing the functional configuration of a control device applied to a makeup water supply system according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram showing an example of the configuration of a blow condition database in the makeup water supply system according to the embodiment of the present invention. [Figure 5] FIG. 2 is a schematic diagram showing an example of the configuration of a water level condition database in the makeup water supply system according to the embodiment of the present invention. [Figure 6] 3 is a flowchart showing an example of a makeup water supply process in the makeup water supply system according to the embodiment of the present invention. [Figure 7] 10 is a graph showing the transition of electrical conductivity, power demand value, and the presence or absence of makeup water due to makeup water supply processing in the makeup water supply system according to an embodiment of the present invention. [Figure 8] FIG. 10 is a block diagram showing an outline of a modification of the makeup water supply system according to the embodiment of the present invention. [Figure 9] FIG. 2 is a schematic diagram showing an example of the configuration of a water level condition database in the makeup water supply system according to the embodiment of the present invention. [Figure 10] 3 is a flowchart showing an example of a makeup water supply process in the makeup water supply system according to the embodiment of the present invention. [Figure 11] FIG. 2 is a schematic diagram showing an example of the configuration of a blow condition database in the makeup water supply system according to the embodiment of the present invention. [Figure 12] 3 is a flowchart showing an example of a makeup water supply process in the makeup water supply system according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0036] Hereinafter, makeup water supply systems, control devices, programs, and makeup water supply methods according to embodiments of the present invention will be described with reference to the drawings. Components indicated by the same reference numerals in the various drawings are the same components. However, unless otherwise specified in the specification, each component is not limited to one, and multiple components may be present.

[0037] Furthermore, descriptions of overlapping configurations and symbols in each drawing may be omitted. Note that the present disclosure is not limited to the following embodiments, and may be implemented by making appropriate modifications, such as omitting configurations or replacing them with different configurations, within the scope of the purpose of the present disclosure.

[0038] <Make-up water supply system> 1A, a makeup water supply system 80 according to a first embodiment of the present invention includes a chiller 82, a cooling tower 84, a cooling water tank 86, a circulation pipe 88, a water supply mechanism 50, a drainage mechanism 60, and a control device 10. The makeup water supply system 80 also includes an electrical conductivity measuring device 20, a watt-hour meter 30, and a water level meter 40.

[0039] (freezer) The refrigerator 82 is a heat exchanger that cools the refrigerant sent from the heat utilization unit 82A (arrow N1) by exchanging heat with cooling water circulating through a circulation pipe 88 via a refrigerant (e.g., R-123) inside the refrigerator 82. The refrigerant cooled by the refrigerator 82 is sent to the heat utilization unit 82A (arrow N2) and used in the heat utilization unit 82A. The heat utilization unit 82A is, for example, an air conditioning device, and lowering the temperature of the refrigerant reduces power consumption during cooling operation.

[0040] (cooling tower) The cooling tower 84 is a heat exchanger that cools the cooling water (arrow N3) sent from the refrigerator 82 via a circulation pipe 88 using latent heat of evaporation. In the cooling tower 84, the cooling water is sprayed from a sprinkler device 84A (arrow N4), and a portion of the cooling water is vaporized by exposure to the outside air AR. In this process, the latent heat of evaporation is consumed, thereby cooling the remaining cooling water. A water tank 84B is provided at the bottom of the cooling tower 84, and the cooling water cooled by the outside air AR is stored in this water tank 84B.

[0041] An overflow pipe 84C is connected to the water tank 84B, which allows the water level in the water tank 84B to be maintained within a predetermined range (below the water level HF).

[0042] (Cooling water tank) Cooling water tank 86 is a water tank that stores cooling water (arrow N5) delivered from cooling tower 84 via circulation pipe 88. Cooling water tank 86 and water tank 84B in cooling tower 84 are connected to each other via circulation pipe 88, so the water levels in cooling water tank 86 and water tank 84B are maintained at approximately the same height.

[0043] In cooling water tank 86, water inlet 86A, through which cooling water delivered from cooling tower 84 is introduced through circulation pipe 88, is provided in the lower part of cooling water tank 86. In addition, in cooling water tank 86, water outlet 86B, through which cooling water to be delivered to chiller 82 is discharged into circulation pipe 88, is provided in the upper part of cooling water tank 86. In other words, water inlet 86A is provided below water outlet 86B.

[0044] Partition plates 86C and 86D are provided inside cooling water tank 86. Partition plate 86C is a partition plate provided on the water outlet 86B side, and its upper end is positioned higher than the water level HF, with a gap between it and the upper end of cooling water tank 86. In addition, the lower end of partition plate 86C is positioned with a gap between it and the lower end of cooling water tank 86.

[0045] On the other hand, the partition plate 86D is a partition plate provided on the water inlet 86A side, and its upper end is positioned lower than the water level HF. The lower end of the partition plate 86D is joined to the lower end of the cooling water tank 86.

[0046] By arranging the partition plates 86C and 86D in this way, the cooling water moves from the water inlet 86A to the water outlet 86B while meandering vertically inside the cooling water tank 86 (arrow N6).

[0047] (circulation pipe) The circulation pipe 88 is a circulation pipe that circulates cooling water from the cooling water tank 86 to the refrigerator 82 (arrow N7), from the refrigerator 82 to the cooling tower 84 (arrow N3), and from the cooling tower 84 to the cooling water tank 86 (arrow N5). The circulation pipe 88 is provided with a pump 88A that moves the cooling water.

[0048] In addition, the circulation pipe 88 is provided with a bypass 88B and a three-way valve 88C for returning the cooling water sent from the refrigerator 82 to the refrigerator 82 again (arrow N8) without passing through the cooling tower 84 and the cooling water tank 86.

[0049] (Water supply mechanism) The water supply mechanism 50 is a device that supplies makeup water (blow makeup water) that is lower in temperature than the cooling water to the water outlet 86B side of the cooling water tank 86, and is configured to include a flow meter 52, a blow valve 54, and a water supply pipe 56.

[0050] The water supply pipe 56 is a pipe having one end connected to a water supply pipe of a building (not shown), and the other end connected to the water outlet 86B side of the cooling water tank 86. The other end of the water supply pipe 56 is located closer to the water outlet 86B than the partition plate 86C.

[0051] The blow valve 54 can start and stop the supply of cooling water from the water supply pipe 56 to the inside of the cooling water tank 86 and adjust the supply amount by opening and closing it and adjusting the opening degree. The flow meter 52 is a device that measures the flow rate of cooling water flowing through the water supply pipe 56.

[0052] (Drainage mechanism) The drainage mechanism 60 is a device that discharges cooling water from the upstream side of the cooling tower 84 in the circulation pipe 88 (i.e., between the chiller 82 and the cooling tower 84), and is composed of a flow meter 62, a blow valve 64, and a drainage pipe 66.

[0053] The drain pipe 66 is a pipe connected at one end to the circulation pipe 88, and at the other end to a drainage drain or the like (not shown). The blow valve 64 can be opened or closed and its opening degree adjusted to start and stop the discharge of cooling water from the drain pipe 66 to the outside of the system, thereby adjusting the discharge amount. The flow meter 62 is a device that measures the flow rate of cooling water flowing through the drain pipe 66 as drainage.

[0054] (Electrical conductivity measuring instrument) The electrical conductivity measuring device 20 is disposed inside the cooling water tank 86 and is a device for measuring the electrical conductivity of the cooling water. By measuring the electrical conductivity, the quality of the cooling water can be determined. When the electrical conductivity is high, the water quality is poorer than when the electrical conductivity is low.

[0055] The electrical conductivity measuring device 20 is disposed at a position closer to the water inlet 86A than the partition plate 86D. The electrical conductivity measuring device 20 is also disposed so that the electrodes for measuring electrical conductivity are located below the upper end of the partition plate 86D.

[0056] (wattmeter) The watt-hour meter 30 measures the amount of power used in, for example, a building. The watt-hour meter 30 also calculates the average value (demand value) of the amount of power used over a 30-minute period. Note that the "power demand value of the building" in the present invention refers to the demand value measured by the watt-hour meter 30.

[0057] (water level gauge) The water level meter 40 is a detection device that is disposed inside the cooling water tank 86 and detects the level of the cooling water. As shown in FIG. 1B, the water level meter 40 includes a plurality of sensors 42A, 42B, 42C, 42D, and 42E that are provided at a predetermined height inside the cooling water tank 86.

[0058] The sensor 42A detects whether the level of the cooling water inside the cooling water tank 86 is higher than the water level HF. The water level HF is the water level at which a full water alarm is issued.

[0059] Furthermore, sensor 42B detects whether the water level of the cooling water inside cooling water tank 86 is higher than a predetermined water level H1, which is lower than water level HF. Water level H1 is the full water (upper limit) position of cooling water tank 86. Sensor 42C detects whether the water level of the cooling water inside cooling water tank 86 is higher than a predetermined water level H2, which is lower than water level H1. Water level H2 is the low water (lower limit) position of cooling water tank 86. Sensor 42D detects whether the water level of the cooling water inside cooling water tank 86 is higher than a predetermined water level HE, which is lower than water level H2. Water level HE is the water level at which a low water level alarm is issued.

[0060] The sensor 42E detects whether the water level of the cooling water inside the cooling water tank 86 is higher than a predetermined water level N that is lower than the water level HE.

[0061] (Control device) The control device 10 shown in FIG. 1A is a device that acquires the power demand value of a building and the electrical conductivity of cooling water, and controls the water supply mechanism and the drainage mechanism based on the acquired power demand value and electrical conductivity.

[0062] <Electrical configuration of the control device> 2 is a block diagram showing the electrical configuration of the control device 10. The control device 10 includes a CPU (Central Processing Unit: processor) 11, a memory 12 serving as a temporary storage area, a nonvolatile storage unit 13, an input unit 14 such as a keyboard and mouse, a display unit 15 such as a liquid crystal display, a medium read / write device (R / W) 16, a communication interface (I / F) unit 18, and an external I / F unit 19. The CPU 11, memory 12, storage unit 13, input unit 14, display unit 15, medium read / write device 16, communication I / F unit 18, and external I / F unit 19 are connected to one another via a bus B1. The medium read / write device 16 reads information written in a recording medium 17 and writes information to the recording medium 17.

[0063] (Storage part) The storage unit 13 is realized by an HDD (Hard Disk Drive), an SSD (Solid State Drive), a flash memory, or the like. A makeup water supply program 13A is stored in the storage unit 13 as a storage medium. The makeup water supply program 13A is stored in the storage unit 13 when a recording medium 17 having the makeup water supply program 13A written therein is set in the medium reading and writing device 16 and the medium reading and writing device 16 reads the makeup water supply program 13A from the recording medium 17. The CPU 11 reads the makeup water supply program 13A from the storage unit 13, expands it in the memory 12, and sequentially executes the processes of the makeup water supply program 13A.

[0064] A blowing condition database 13B and a water level condition database 13C are stored in the storage unit 13. The blowing condition database 13B and the water level condition database 13C will be described in detail later.

[0065] (Input section) The user performs operations for starting and ending the makeup water supply program 13A on the input unit 14. The user is, for example, the administrator of the makeup water supply system 80.

[0066] (Display) Information (for example, input buttons) for starting and ending the makeup water supply program 13A is displayed on the display unit 15. The input unit 14 and the display unit 15 may be omitted as appropriate.

[0067] <Functional configuration of the control device> Next, the functional configuration of the control device 10 will be described with reference to Fig. 3. As shown in Fig. 2, the control device 10 includes a blow condition acquisition unit 11A, a water level condition acquisition unit 11B, and a control unit 11C. The CPU 11 (see Fig. 2) of the control device 10 executes a makeup water supply program 13A, thereby functioning as the blow condition acquisition unit 11A, the water level condition acquisition unit 11B, and the control unit 11C.

[0068] (Blow condition acquisition section, water level condition acquisition section) The blowing condition acquisition unit 11A acquires the electrical conductivity EC (see FIG. 4) of the cooling water measured by the electrical conductivity measuring device 20. The blowing condition acquisition unit 11A also acquires the building's power demand value PD (see FIG. 4) measured by the watt-hour meter 30. Meanwhile, the water level condition acquisition unit 11B acquires the cooling water level detected by the water level meter 40.

[0069] (Control unit) The control unit 11C acquires the building's power demand value PD and the cooling water's electrical conductivity from the blow condition acquisition unit 11A and the water level condition acquisition unit 11B. Then, the control unit 11C controls the water supply mechanism 50 and the drainage mechanism 60 based on the acquired power demand value PD and electrical conductivity EC using a blow condition database 13B and a water level condition database 13C, which will be described below.

[0070] (Blow condition database) 4 shows the blowing condition database 13B. The blowing condition database 13B is a database in which the "first condition" for supplying makeup water by the water supply mechanism 50 (see FIG. 1) and discharging cooling water by the drainage mechanism 60 is stored.

[0071] By using the blowing condition database 13B, combinations of the measured cooling water electrical conductivity EC and the building power demand value PD are classified into the following six modes. Note that the electrical conductivity EC2 shown in each of the following modes is an example of the "first predetermined value" in the present invention, and the electrical conductivity EC1 is an example of the "second predetermined value" in the present invention. Similarly, the power demand value PD1 is an example of the "predetermined value of the power demand value" in the present invention.

[0072] Mode 1: The electrical conductivity EC of the cooling water is greater than a predetermined electrical conductivity EC2. (EC2 <EC) The building's power demand value PD is less than or equal to the predetermined power demand value PD1. (PD≦PD1)

[0073] Mode 2: The electrical conductivity EC of the cooling water is greater than the specified electrical conductivity EC1 and less than or equal to EC2. (EC1 <EC≦EC2) The building's power demand value PD is less than or equal to the predetermined power demand value PD1. (PD≦PD1)

[0074] Mode 3: The electrical conductivity EC of the cooling water is equal to or less than the specified electrical conductivity EC1. (EC≦EC1) The building's power demand value PD is less than or equal to the predetermined power demand value PD1. (PD≦PD1)

[0075] Mode 4: The electrical conductivity EC of the cooling water is greater than a predetermined electrical conductivity EC2. (EC2 <EC) The building power demand value PD is greater than a predetermined power demand value PD1. (PD1 <PD)

[0076] Mode 5: The electrical conductivity EC of the cooling water is greater than the specified electrical conductivity EC1 and less than or equal to EC2. (EC1 <EC≦EC2) The building power demand value PD is greater than a predetermined power demand value PD1. (PD1 <PD)

[0077] Mode 6: The electrical conductivity EC of the cooling water is equal to or less than the specified electrical conductivity EC1. (EC≦EC1) The building power demand value PD is greater than a predetermined power demand value PD1. (PD1 <PD)

[0078] In modes 1, 4, 5, and 6, the "first condition" for supplying makeup water and discharging cooling water is met. In Fig. 4, the satisfaction of the first condition is indicated as "OK."

[0079] Also, in Modes 2 and 3, the "First Condition" for supplying makeup water and discharging cooling water is not satisfied. In FIG. 4, the fact that the First Condition is not satisfied is indicated as "NG".

[0080] (Water level condition database) FIG. 5 shows a water level condition database 13C. The water level condition database 13C is a database that stores the "Second Condition" for supplying makeup water by the water supply mechanism 50 (see FIG. 1) and discharging cooling water by the drainage mechanism 60.

[0081] By using the water level condition database 13C, for each mode classified using the blow condition database 13B, whether to supply makeup water by the water supply mechanism 50 (see FIG. 1) and discharge cooling water by the drainage mechanism 60 is determined as follows.

[0082] Modes 1, 4, 5, 6 (First condition "OK"): When the water level H of the cooling water is lower than the water level H1 (H < H1), supply makeup water. Otherwise, do not supply. When the water level H of the cooling water is higher than the water level H2 (H2 < H), discharge the cooling water. Otherwise, do not discharge.

[0083] Modes 2, 3 (First condition "NG"): When the water level H of the cooling water is lower than the water level H2 (H < H2), supply makeup water. Otherwise, do not supply. When the water level H of the cooling water is higher than the water level H1 (H1 < H), discharge the cooling water. Otherwise, do not discharge.

[0084] That is, even when the "First Condition" for supplying makeup water and discharging cooling water is satisfied by the combination of the measured electrical conductivity EC of the cooling water and the building's power demand value PD, if the water level H of the cooling water is outside the predetermined range, the supply of makeup water and the discharge of cooling water are not carried out.

[0085] Furthermore, even if the "first condition" for supplying makeup water and discharging cooling water is not met by the combination of the measured cooling water electrical conductivity EC and the building power demand value PD, the supply of makeup water and the discharge of cooling water are carried out if the cooling water level H is within a predetermined range. Note that the supply of makeup water and the discharge of cooling water can be carried out simultaneously.

[0086] <effect> Next, the operation of the makeup water supply system 80 according to this embodiment will be described with reference to Figures 6 and 7. In response to an execution instruction from the user via the input unit 14, the CPU 11 of the control device 10 executes the makeup water supply program 13A, thereby executing the makeup water supply process shown in Figure 6.

[0087] To avoid confusion, the following description is based on the assumption that the temperature of the makeup water is lower than that of the cooling water. The flow rates of the makeup water supplied and the cooling water discharged per unit time are predetermined.

[0088] (Make-up water supply treatment) When execution of the makeup water supply program 13A is started, the CPU 11 acquires the electrical conductivity EC of the cooling water, the power demand value PD of the building, and the water level H of the cooling water in the cooling water tank 86 in step 102.

[0089] In step 104, the CPU 11 determines whether the electrical conductivity EC is greater than a predetermined electrical conductivity EC2, and if the determination is affirmative, the process proceeds to step 105. On the other hand, if the determination is negative in step 104, the process proceeds to step .

[0090] In step 105, the CPU 11 determines whether the building power demand value PD is greater than a predetermined power demand value PD1, and if the determination is affirmative, the process proceeds to step 106. On the other hand, if the determination is negative in step 105, the process proceeds to step 107.

[0091] In step 106, the CPU 11 reads the blowing condition database 13B and classifies the combination of the electrical conductivity EC and the building power demand value PD as mode 4. After step 106, the process proceeds to step 130.

[0092] In step 107, the CPU 11 reads the blowing condition database 13B and classifies the combination of the electrical conductivity EC and the building power demand value PD as mode 1. After step 107, the process proceeds to step .

[0093] In step 108, the CPU 11 determines whether the electrical conductivity EC is greater than a predetermined electrical conductivity EC1, and if the determination is affirmative, the process proceeds to step 110. On the other hand, if the determination is negative in step 108, the process proceeds to step 112.

[0094] In step 110, the CPU 11 determines whether the building power demand value PD is greater than a predetermined power demand value PD1, and if the determination is affirmative, the process proceeds to step 114. On the other hand, if the determination is negative in step 110, the process proceeds to step 116.

[0095] In step 114, the CPU 11 reads the blowing condition database 13B and classifies the combination of the electrical conductivity EC and the building power demand value PD as mode 5. After step 114, the process proceeds to step .

[0096] In step 116, the CPU 11 reads the blowing condition database 13B and classifies the combination of the electrical conductivity EC and the building power demand value PD as mode 2. After step 116, the process proceeds to step 140.

[0097] In step 112, the CPU 11 determines whether the building power demand value PD is greater than a predetermined power demand value PD1, and if the determination is affirmative, the process proceeds to step 118. On the other hand, if the determination is negative in step 112, the process proceeds to step 120.

[0098] In step 118, the CPU 11 reads the blowing condition database 13B and classifies the combination of the electrical conductivity EC and the building power demand value PD as mode 6. After step 118, the process proceeds to step .

[0099] In step 120, the CPU 11 reads the blowing condition database 13B and classifies the combination of the electrical conductivity EC and the building power demand value PD as mode 3. After step 120, the process proceeds to step 140.

[0100] In step 130, the CPU 11 determines whether the cooling water level H in the cooling water tank 86 is lower than a predetermined water level H1, and if the determination is affirmative, the process proceeds to step 132. In step 132, the CPU 11 controls the water supply mechanism 50 to start supplying makeup water. After step 132, the process proceeds to step 134.

[0101] On the other hand, if the determination in step 130 is negative, the process proceeds to step 134. That is, the process proceeds to step 134 without starting the supply of makeup water.

[0102] In step 134, the CPU 11 determines whether the water level H of the cooling water in the cooling water tank 86 is higher than a predetermined water level H2, and if the determination is affirmative, the process proceeds to step 136. In step 136, the CPU 11 controls the drain mechanism 60 to start discharging the cooling water. After step 136, the process proceeds to step 150.

[0103] On the other hand, if the determination in step 134 is negative, the process proceeds to step 150. That is, the process proceeds to step 150 without starting the discharge of the cooling water.

[0104] In step 140, the CPU 11 determines whether the cooling water level H in the cooling water tank 86 is lower than a predetermined water level H2, and if the determination is affirmative, the process proceeds to step 142. In step 142, the CPU 11 controls the water supply mechanism 50 to start supplying makeup water. After step 142, the process proceeds to step 144.

[0105] On the other hand, if the determination in step 140 is negative, the process proceeds to step 144. That is, the process proceeds to step 144 without starting the supply of makeup water.

[0106] In step 144, the CPU 11 determines whether the water level H of the cooling water in the cooling water tank 86 is higher than a predetermined water level H1, and if the determination is affirmative, the process proceeds to step 146. In step 146, the CPU 11 controls the drain mechanism 60 to start discharging the cooling water. After step 146, the process proceeds to step 150.

[0107] On the other hand, if the determination at step 144 is negative, the process proceeds to step 146. That is, the process proceeds to step 150 without starting the discharge of the cooling water.

[0108] In step 150, the CPU 11 determines whether the time to end the makeup water supply process has arrived, and if the determination is affirmative, the makeup water supply process is terminated. This termination time arrives, for example, when the administrator of the makeup water supply system 80 inputs an end of the makeup water supply process via the input unit 14. If the determination is negative in step 150, the process returns to step 102.

[0109] <Effects> In the makeup water supply system 80 according to the embodiment of the present invention, the refrigerant sent from the heat utilization section 82A shown in Fig. 1A is cooled by the refrigerator 82. This allows the cooled refrigerant to be sent to the heat utilization section 82A.

[0110] The cooling water that has exchanged heat with the refrigerant is cooled in the cooling tower 84. In the cooling tower 84, the cooling water is cooled by the latent heat of evaporation. As the cooling water evaporates, the amount of cooling water in the makeup water supply system 80 gradually decreases. However, because the makeup water supply system 80 is provided with the cooling water tank 86, the amount of cooling water is greater than in a system that does not have the cooling water tank 86. Therefore, even if the cooling water evaporates, a sudden increase in the electrical conductivity EC is suppressed. Furthermore, because the control device 10 controls the water supply mechanism 50 based on the electrical conductivity EC, it is possible to supply makeup water to lower the electrical conductivity EC when the electrical conductivity EC becomes high.

[0111] The control device 10 also controls the water supply mechanism 50 based on the building's power demand value PD. When the power demand value PD increases, makeup water that is lower in temperature than the cooling water can be supplied, thereby lowering the temperature of the cooling water sent to the chiller 82. This reduces the amount of power consumed, thereby suppressing the power demand value PD. The water supply mechanism 50 is also provided on the water outlet 86B side of the cooling water tank 86. This allows the makeup water to be sent to the chiller 82 before it is completely mixed with the cooling water in the cooling water tank 86. This allows cooling water at a low temperature to be sent to the chiller 82. This is highly effective in reducing power consumption.

[0112] In this way, in the makeup water supply system 80, by controlling the supply of makeup water to the cooling water sent to the refrigerator 82, the electrical conductivity EC of the cooling water can be adjusted and the power demand value PD can be suppressed.

[0113] Next, the supply of makeup water corresponding to each mode will be described with reference to Fig. 7. Fig. 7 shows the changes over time in the electrical conductivity EC, the power demand value PD, and whether makeup water is being supplied when the control device 10 in the makeup water supply system 80 executes makeup water supply processing.

[0114] 7, it is assumed that the supply of makeup water is started and stopped based on the "first condition" determined from the electrical conductivity EC and the power demand value PD. In other words, the supply of makeup water and the drainage of cooling water based on the "second condition" determined from the water level of the cooling water inside the cooling water tank 86 are not taken into consideration.

[0115] 7, in the makeup water supply system 80, when the electrical conductivity EC is greater than the first predetermined value (EC2) (mode 1, mode 4), the "first condition" for supplying makeup water by the water supply mechanism 50 is satisfied, and makeup water is supplied. This prevents the electrical conductivity EC from significantly exceeding the first predetermined value (EC2), regardless of the power demand value PD.

[0116] Furthermore, as shown at times t3 to t4 and t5 to t6, in the makeup water supply system 80, when the electrical conductivity EC is greater than a second predetermined value (EC1) that is smaller than the first predetermined value (EC2) and the power demand value PD is greater than a predetermined value (mode 5), the "first condition" is satisfied and makeup water is supplied. This prevents the power demand value PD from significantly exceeding the predetermined value (PD1) when the electrical conductivity EC is greater than the second predetermined value (EC1).

[0117] In this case, for example, when the power demand value at which the contracted power and basic fee with the power company become high is a threshold value PD2, it is preferable to adjust the opening of the blow valve 54 and the flow rate of makeup water so that the power demand value PD is always less than the threshold value PD2. This makes it possible to suppress an increase in the power demand value PD, as shown by the dashed line K in Fig. 7.

[0118] Furthermore, as shown between times t4 and t5, in makeup water supply system 80, if the electrical conductivity EC is greater than the second predetermined value (EC1) and the power demand value PD is equal to or less than the predetermined value (PD1) (mode 2), the "first condition" is not met and makeup water is not supplied. In other words, even if the electrical conductivity EC is equal to or greater than the second predetermined value (EC1), makeup water is not supplied if the power demand value PD is equal to or less than the predetermined value (PD1). This makes it possible to prevent excessive supply of makeup water.

[0119] Furthermore, as shown from time t6 to t7, in the makeup water supply system 80, when the electrical conductivity EC is equal to or less than the second predetermined value (EC1) and the power demand value PD is greater than the predetermined value (PD1) (mode 6), the "first condition" is satisfied and makeup water is supplied. That is, even if the electrical conductivity EC is equal to or less than the second predetermined value (EC1), makeup water is supplied if the power demand value PD is greater than the predetermined value (PD1). This prevents the power demand value PD from significantly exceeding the predetermined value (PD1), regardless of the electrical conductivity EC.

[0120] Furthermore, as shown from time t7 to t8, when the electrical conductivity EC is equal to or less than a second predetermined value (EC1) and the power demand value PD is equal to or less than a predetermined value (PD1), makeup water may not be supplied (mode 3), thereby preventing excessive supply of makeup water.

[0121] In the makeup water supply system 80 according to the embodiment of the present invention, as shown in FIG. 1A, partition plates 86C and 86D are provided in the cooling water tank 86 between the water inlet 86A and the water outlet 86B.

[0122] Among these, the partition plate 86C provided on the water outlet 86B side makes it difficult for makeup water supplied to the water outlet 86B side to mix with the cooling water on the water inlet 86A side in the cooling water tank 86. This makes it easier to supply cold cooling water to the refrigerator 82.

[0123] In addition, the partition plate 86D provided on the water inlet 86A side makes it difficult for the cooling water on the water inlet 86A side to mix with the makeup water supplied to the water outlet 86B side in the cooling water tank 86. This makes it possible to measure the electrical conductivity of the cooling water in a state where it is not diluted with makeup water.

[0124] Furthermore, in the makeup water supply system 80 according to the embodiment of the present invention, the control device 10 controls the drainage mechanism 60 in addition to the water supply mechanism 50 to discharge the cooling water. Because the drainage mechanism 60 is provided upstream of the cooling tower 84, the cooling water that has undergone heat exchange with the refrigerant in the chiller 82 and the cooling water before being cooled in the cooling tower 84 are discharged. In other words, it is possible to discharge cooling water that is relatively hot within the makeup water supply system 80. This makes it easier to maintain the temperature of the cooling water low.

[0125] Furthermore, in the makeup water supply system 80 according to the embodiment of the present invention, the control device 10 controls the water supply mechanism 50 based on the water level in the cooling water tank 86 measured by the water level gauge 40. As a result, even when the supply of makeup water would be stopped under control based on the power demand value PD and the electrical conductivity EC (i.e., when the above-mentioned "first condition" is not satisfied), makeup water is supplied when the water level falls below a lower limit value (water level H2, see FIG. 5), thereby preventing the makeup water supply system 80 from running out of cooling water.

[0126] Furthermore, in the control based on the power demand value PD and the electrical conductivity EC, even when makeup water is supplied (i.e., when the above-mentioned "first condition" is satisfied), if the water level reaches or exceeds the upper limit value (water level H1, see Figure 5), the supply of makeup water is stopped, thereby preventing cooling water from overflowing from within the makeup water supply system 80.

[0127] Furthermore, in the makeup water supply system 80 according to the embodiment of the present invention, the control device 10 controls the drain mechanism 60 based on the water level in the cooling water tank 86 measured by the water level gauge 40. As a result, when the water level exceeds a predetermined water level (water level H1 or H2, see FIG. 5), the water is forcibly "drained," thereby preventing the cooling water from overflowing from the makeup water supply system 80. When the water level falls below the predetermined water level (water level H1 or H2, see FIG. 5), the drainage is "stopped," preventing the cooling water from running out of water in the makeup water supply system 80.

[0128] <Other embodiments> (Drainage mechanism omitted) As shown in Fig. 1, the makeup water supply system 80 according to the above embodiment includes a drainage mechanism 60 that discharges cooling water from the circulation pipe 88 on the upstream side of the cooling tower 84, but the embodiment of the present invention is not limited to this. For example, as shown in Fig. 8, such a drainage mechanism 60 may be omitted.

[0129] In this case, the cooling water in makeup water supply system 80, which has increased in volume as a result of mixing with makeup water supplied from water supply mechanism 50, is discharged from overflow pipe 84C of water tank 84B. If drainage mechanism 60 is not provided, as shown in FIG. 9, the conditions for drainage are not recorded in water level condition database 13C.

[0130] Furthermore, in the makeup water supply process, steps 134, 136, 144, and 146 shown in FIG. 6 are not executed, and as shown in FIG. 10, if a negative judgment is made in step 130, after step 132, if a negative judgment is made in step 140, or after step 142, the process proceeds to step 150.

[0131] (Modification of control contents in mode 6) In the above embodiment, the "first condition" is met when the electrical conductivity EC is equal to or less than the second predetermined value (EC1) and the power demand value PD is greater than the predetermined value (PD1) (mode 6), as shown in Fig. 4. If the "second condition" is met, makeup water is supplied as shown in Fig. 7 from time t6 to time t7.

[0132] However, the embodiment of the present invention is not limited to this. For example, as shown in Fig. 11, the "first condition" may not be satisfied in mode 6. If the "second condition" is also satisfied, makeup water is not supplied between times t6 and t7 in Fig. 7. In this case, in the makeup water supply process, the process proceeds to step 140 after step 118, as shown in Fig. 12.

[0133] That is, even if the power demand value PD is greater than the predetermined value (PD1), makeup water is not supplied if the electrical conductivity EC is equal to or less than the second predetermined value (EC1). This makes it possible to prevent excessive supply of makeup water regardless of the power demand value PD.

[0134] (Other variations) In the above embodiment, for example, the following various processors can be used as the hardware structure of the processing unit that executes the processes of the blow condition acquisition unit 11A, the water level condition acquisition unit 11B, and the control unit 11C. As described above, the various processors include a CPU, which is a general-purpose processor that executes software (programs) and functions as a processing unit, as well as dedicated electrical circuits that are processors with a circuit configuration specifically designed to execute specific processes, such as a programmable logic device (PLD) that is a processor whose circuit configuration can be changed after manufacture, such as an FPGA (Field-Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit).

[0135] The processing unit may be configured with one of these various processors, or may be configured with a combination of two or more processors of the same or different types (for example, a combination of multiple FPGAs, or a combination of a CPU and an FPGA).The processing unit may also be configured with a single processor.

[0136] Examples of configuring a processing unit with a single processor include, first, a form in which one processor is configured with a combination of one or more CPUs and software, and this processor functions as the processing unit, as typified by computers such as client and server. Second, a form in which a processor is used to realize the functions of the entire system, including the processing unit, on a single IC (Integrated Circuit) chip, as typified by systems on chips (SoCs). In this way, the processing unit is configured using one or more of the above-mentioned various processors as a hardware structure.

[0137] Furthermore, the hardware structure of these various processors can be, more specifically, an electric circuit that combines circuit elements such as semiconductor elements. As described above, the present invention can be embodied in various ways. [Explanation of symbols]

[0138] 10 Control device 20 Electrical conductivity measuring instrument 30 Energy meter 40 Water level gauge 50 Water supply mechanism 60 Drainage mechanism 80 Make-up Water Supply System 82 Refrigeration Machine 82A Heat utilization section 84 Cooling Tower 86 Cooling Water Tank 86A Water inlet 86B Water outlet 86C Partition 86D Partition board 88 Circulation tube

Claims

1. a refrigerator that cools the refrigerant sent from the heat utilization unit by heat exchange with cooling water; a cooling tower that cools the cooling water sent from the refrigerator; a cooling water tank that stores the cooling water sent from the cooling tower; a circulation pipe for circulating the cooling water from the cooling water tank to the refrigerator, from the refrigerator to the cooling tower, and from the cooling tower to the cooling water tank; a water supply mechanism for supplying makeup water having a temperature lower than that of the cooling water to a water outlet side of the cooling water tank; a control device that acquires a power demand value of a building and an electrical conductivity of the cooling water, and controls the water supply mechanism based on the acquired power demand value and the acquired electrical conductivity; A makeup water supply system comprising:

2. The control device controlling the water supply mechanism to supply the makeup water at least when the electrical conductivity is greater than a first predetermined value, and when the electrical conductivity is greater than a second predetermined value that is smaller than the first predetermined value and the power demand value is greater than a predetermined value; The makeup water supply system of claim 1 .

3. 3. The makeup water supply system according to claim 1, wherein a partition plate is provided between the water inlet and the water outlet in the cooling water tank.

4. a drainage mechanism that discharges the cooling water from the circulation pipe upstream of the cooling tower; The control device controls the drainage mechanism. The makeup water supply system according to any one of claims 1 to 3.

5. The control device acquiring the water level in the cooling water tank; controlling the water supply mechanism based on the acquired water level; The makeup water supply system according to any one of claims 1 to 3.

6. The control device acquiring the water level in the cooling water tank; controlling the water supply mechanism and the drainage mechanism based on the acquired water level; The makeup water supply system of claim 4.

7. a refrigerator that cools the refrigerant sent from the heat utilization unit by heat exchange with cooling water; a cooling tower that cools the cooling water sent from the refrigerator; a cooling water tank that stores the cooling water sent from the cooling tower; a circulation pipe for circulating the cooling water from the cooling water tank to the refrigerator, from the refrigerator to the cooling tower, and from the cooling tower to the cooling water tank; a water supply mechanism for supplying makeup water having a temperature lower than that of the cooling water to a water outlet side of the cooling water tank; and disposed in a makeup water supply system comprising: a processor; the processor acquires a power demand value of the building and an electrical conductivity of the cooling water, and controls the water supply mechanism based on the acquired power demand value and the acquired electrical conductivity. Control device.

8. obtaining a building power demand value; a step of acquiring the electrical conductivity of the cooling water circulating among a refrigerator that cools the refrigerant sent from the heat utilization unit by heat exchange with cooling water, a cooling tower that cools the cooling water sent from the refrigerator, and a cooling water tank that stores the cooling water sent from the cooling tower; controlling a water supply mechanism that supplies blow makeup water to the water outlet side of the cooling water tank based on the acquired power demand value and the acquired electrical conductivity; A program that causes a computer to execute the following.

9. obtaining a building power demand value; a step of acquiring the electrical conductivity of the cooling water circulating among a refrigerator that cools the refrigerant sent from the heat utilization unit by heat exchange with cooling water, a cooling tower that cools the cooling water sent from the refrigerator, and a cooling water tank that stores the cooling water sent from the cooling tower; controlling a water supply mechanism that supplies blow makeup water to the water outlet side of the cooling water tank based on the acquired power demand value and the acquired electrical conductivity; Provided makeup water supply method.

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