How to operate a chilled water chiller

Abstract

To provide a cold water chiller capable of effectively reducing predetermined bacteria in cooling water without stopping the whole device while controlling a temperature of cooling water, and a method for operating the cold water chiller.SOLUTION: A cold water chiller 1 comprises: a sprinkling part 3 that cools cooling water by sprinkling the cooling water heated by a heat source onto a filler 9; three water storage parts 51, 52, 53 for each sprinkling part 3 that store the cooling water drained from the sprinkling part 3; a distribution part 4 that distributes the cooling water drained from one sprinkling part 3 to each of the water storage parts 51, 52, 53; a delivery part 6 that delivers the cooling water from each of the water storage parts 51, 52, 53 to the heat source; and a supply part 7 that supplies the cooling water to each of the water storage parts 51, 52, 53.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to cold a method of operating a water chiller.

Background Art

[0002] Among water chillers for cooling a heat source, some include a cooling tower. The cooling tower includes a water spraying section that sprays cooling water onto a filler, and a water storage section provided below the water spraying section. The cooling water sprayed onto the filler is cooled by utilizing the heat of vaporization. The cooling water cooled by the water spraying section is drained downward and stored in the water storage section. By sending the cooling water in this water storage section to the heat source, the heat source is cooled. The cooling water heated by the heat source is sent back to the water spraying section again.

[0003] Since the above cycle is repeated, not only does the cooling water in the water storage section decrease due to vaporization, but also the components contained in the cooling water may be concentrated, and there is a possibility that predetermined bacteria may be generated and proliferated. For this reason, it was necessary to periodically replace the cooling water in the water storage section. As a method of replacing the cooling water, for example, there are a method of adding fresh cooling water to the water storage section while operating the water chiller, a method of completely stopping the water chiller and replacing the cooling water in the water storage section, and a method of adding a bactericidal agent to the cooling water.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, with the conventional technology described above, it is difficult to control the temperature of the cooling water because its temperature is determined by the balance between the supply water temperature, the ambient temperature, and the cooling load on the heat source. In addition, with methods such as adding fresh cooling water to the reservoir, it is difficult to completely replace the cooling water in the reservoir. As a result, there is a problem in that it is difficult to reduce the number of specific bacteria in the cooling water. Furthermore, it is difficult to obtain the sterilizing effect of disinfectants. In a method that involves completely stopping the chilled water chiller and replacing the cooling water in the reservoir, the heat source cannot be cooled during that time, which could potentially cause malfunctions in the heat source.

[0006] Therefore, the present invention can effectively reduce a predetermined number of bacteria in the cooling water without stopping the entire device, while controlling the temperature of the cooling water. cold This document provides a method for operating a water chiller. [Means for solving the problem]

[0007] To solve the above problems, the chilled water chiller according to the present invention comprises: a water spraying unit that cools the cooling water by spraying the cooling water heated by a heat source onto a packing material; a plurality of water storage units that store the cooling water drained from one of the water spraying units; a distribution unit that distributes the cooling water drained from one of the water spraying units to each of the water storage units; a discharge unit that sends the cooling water from each of the water storage units to the heat source; and a supply unit that supplies the cooling water to each of the water storage units.

[0008] This configuration allows for continued cooling of the heat source using other water reservoirs while the cooling water in one reservoir is being replaced. By monitoring the temperature of the cooling water stored in each reservoir, it becomes possible to control the cooling water temperature, for example, by prioritizing the cooling of the water in the reservoir with a relatively higher temperature. In this way, it is possible to effectively reduce the number of specific bacteria in the cooling water of the reservoirs without stopping the chilled water chiller.

[0009] In the above configuration, the supply unit may have a chemical injection unit that increases the concentration of the disinfectant in the cooling water supplied from the supply unit to the water storage unit.

[0010] By configuring the system in this way, the sterilization effect of the cooling water can be automatically enhanced. As a result, the specific bacteria in the cooling water can be reduced more effectively.

[0011] A method for operating the chilled water chiller described above, the method for operating the chilled water chiller according to claim 1, comprising: a first temperature comparison step of comparing the temperature of the cooling water in the water storage section, the temperature of the cooling water in the distribution section, and the temperature of the cooling water in the supply section; a first water storage volume determination step of determining whether the amount of cooling water stored in each of the water storage sections is below the upper limit water level; a water storage section in which it is determined by the first temperature comparison step that the cooling water stored is at a higher temperature than the temperature of the cooling water in the supply section is designated as a first high-temperature water storage section; a water storage section in which it is determined by the first water storage volume determination step that the amount of water stored is below the upper limit water level is designated as a small-volume water storage section; and in the first high-temperature water storage section, and When the storage unit, which is a small amount of water storage unit, is designated as a first high-temperature small amount of water storage unit, and the first temperature comparison step determines that the temperature of the cooling water in the supply unit is lower than the temperature of the cooling water in the distribution unit, and there is at least one first high-temperature small amount of water storage unit, the system includes: a first cooling water supply step of supplying the cooling water from the supply unit to any of the first high-temperature small amount of water storage units; a first cooling water delivery step of sending the cooling water from the storage units other than the one in which the first cooling water supply step is performed to the heat source using the delivery unit; and a first cooling water recirculation step of recirculating the cooling water through the distribution unit to the storage unit in which the first cooling water delivery step is performed, after the first cooling water supply step.

[0012] This method allows for efficient cooling of the cooling water in each reservoir, as well as efficient cooling of the heat source. Furthermore, it makes it easy to control the temperature of the cooling water.

[0013] A method for operating the above-described chilled water chiller, comprising: a first temperature comparison step of comparing the temperature of the cooling water in the water storage section, the temperature of the cooling water in the distribution section, and the temperature of the cooling water in the supply section; a first water volume determination step of determining whether the amount of cooling water stored in each of the water storage sections is below the upper limit water level; a water storage section in which the first temperature comparison step determines that the cooling water stored is at a higher temperature than the temperature of the cooling water in the distribution section is designated as a second high-temperature water storage section; a water storage section in which the first water volume determination step determines that the amount of water stored is below the upper limit water level is designated as a small-volume water storage section; and the second high-temperature water storage section is also the small-volume water storage section. When the water storage section is designated as a second high-temperature small-volume water storage section, if the first temperature comparison step determines that the temperature of the cooling water in the distribution section is lower than the temperature of the cooling water in the supply section, and there is at least one second high-temperature small-volume water storage section, the system includes: a second cooling water supply step of supplying the cooling water from the distribution section to any of the second high-temperature small-volume water storage sections; a second cooling water delivery step of using the delivery section to deliver the cooling water from the water storage sections other than the one in which the second cooling water supply step is being performed to the heat source; and a second cooling water recirculation step of returning the cooling water to the water storage section in which the second cooling water delivery step is being performed via the distribution section, after the second cooling water supply step.

[0014] This method allows for efficient cooling of the cooling water in each reservoir, as well as efficient cooling of the heat source. Furthermore, it makes it easy to control the temperature of the cooling water.

[0015] A method for operating the above-described chilled water chiller, comprising: a third cooling water delivery step in which the delivery unit delivers the cooling water from one of the plurality of water storage units to the heat source; a second temperature comparison step in which, if the temperature of the cooling water heated by the heat source exceeds a predetermined upper temperature value during the third cooling water delivery step, the temperature of the cooling water in the water storage unit where the third cooling water delivery step is being performed is compared with the temperature of the cooling water in the water storage unit other than the one where the third cooling water delivery step is being performed; and a determination of whether the amount of cooling water stored in each of the water storage units is below the lower limit water level. The system includes a second water storage volume determination step, and a fourth cooling water delivery step in which, if the second temperature comparison step determines that the temperature of the cooling water in a water storage section other than the one in which the third cooling water delivery step is performed is lower than the temperature of the cooling water in the water storage section in which the third cooling water delivery step is performed, and the second water storage volume determination step determines that the amount of cooling water stored in the water storage section other than the one in which the third cooling water delivery step is performed is higher than the lower limit water level, the delivery unit delivers the cooling water from the water storage section other than the one in which the third cooling water delivery step is performed to the heat source.

[0016] This method makes it possible to cool the heat source efficiently.

[0017] The above method may include: a bacterial concentration determination step of determining whether the concentration of a predetermined bacterial component in the cooling water in each of the water storage units is above an upper limit; a drainage step of draining the cooling water from the water storage unit in which the bacterial concentration determination step determines that the concentration of the bacterial component is above an upper limit; and a third cooling water supply step of supplying the cooling water from the supply unit to the water storage unit in which the drainage step was performed, after the drainage step.

[0018] By using this method, if the concentration of a specified bacterial component in the cooling water of the reservoir exceeds the upper limit, the cooling water in the reservoir can be quickly replaced. Therefore, the specified bacteria in the cooling water can be rapidly reduced.

[0019] In the above method, in the third cooling water supply step, a chemical agent injection step of injecting a bactericidal chemical agent into the cooling water may be included.

[0020] By adopting such a method, the bactericidal effect of the cooling water can be rapidly enhanced. Therefore, a predetermined type of bacteria in the cooling water can be more effectively reduced.

Advantages of the Invention

[0021] According to the present invention, while controlling the temperature of the cooling water of the water chiller, a predetermined type of bacteria in the cooling water can be effectively reduced without stopping the water chiller.

Brief Description of the Drawings

[0022] [Figure 1] FIG. 1 is a schematic configuration diagram of a water chiller in an embodiment of the present invention. In the following description, the upper side in the gravitational direction is simply referred to as the upper side, and the lower side in the gravitational direction is simply referred to as the lower side. [Figure 2] FIG. 2 is a flowchart showing the operation of the water chiller in an embodiment of the present invention. [Figure 3] FIG. 3 is a flowchart showing the operation of water supply and cold storage in an embodiment of the present invention. [Figure 4] FIG. 4 is a flowchart showing the operation of circulating cold storage in an embodiment of the present invention. [Figure 5] FIG. 5 is a flowchart showing the operation of cold storage output in an embodiment of the present invention. [Figure 6] FIG. 6 is a flowchart showing the operation of drainage operation in an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0023] Next, embodiments of the present invention will be described based on the drawings.

[0024] <Water Chiller> FIG. 1 is a schematic configuration diagram of the water chiller 1. In the following description, the upper side in the gravitational direction is simply referred to as the upper side, and the lower side in the gravitational direction is simply referred to as the lower side. As shown in Figure 1, the chilled water chiller 1 cools an object (not shown) using cooling water sent to a heat exchanger (heat source) 2. The chilled water chiller 1 comprises a heat exchanger 2 for cooling the object, a spraying section 3 from which the cooling water heated by the heat exchanger 2 is sent, a distribution section 4 located below the spraying section 3, three water storage sections 51, 52, 53 (first water storage section 51, second water storage section 52, third water storage section 53) located below the distribution section 4, a delivery section 6 connecting each water storage section 51, 52, 53 to the heat exchanger 2, a supply section 7 for supplying cooling water to each water storage section 51, 52, 53, and a drainage section 5 for draining the cooling water from each water storage section 51, 52, 53.

[0025] <Sprinkler section> The water spraying unit 3 cools the cooling water heated by the heat exchanger 2. The water spraying unit 3 is housed in a housing 80 that is open in the vertical direction and contains a water spraying pipe 8, a packing material 9, and a fan 10. The water spraying pipe 8 is connected to the heat exchanger 2 via a return channel 20. The return channel 20 is equipped with a return channel thermometer 11 that detects the temperature of the cooling water flowing through the return channel 20. Numerous holes are formed in the water spraying pipe 8, and the cooling water is sprayed onto the packing material 9.

[0026] The packing material 9 is located below the water sprinkler pipe 8. The packing material 9 is composed of multiple stacked plate-shaped members, for example, made of resin. Cooling water sprayed onto the packing material 9 falls downwards as droplets. During this time, the cooling water is cooled by the heat of vaporization caused by contact with the outside air.

[0027] The fan 10 is located above the water spray pipe 8. The fan 10 draws in air from inside the housing 80 and exhausts it from above. This actively draws outside air into the housing 80, and the outside air passes through the packing material 9. This promotes the vaporization of the cooling water sprayed on the packing material 9, and the cooling water is cooled efficiently. Although not shown in the diagram, an eliminator is provided between the fan 10 and the water spray pipe 8. This suppresses the scattering of cooling water to the outside of the housing 80.

[0028] <Distribution section> The distribution unit 4 distributes the cooling water dripping from the packing material 9 to three water storage units 51, 52, and 53. The distribution unit 4 comprises a main flow path 12 connected to the water spraying unit 3, and three distribution paths 13, 14, and 15 (first distribution path 13, second distribution path 14, and third distribution path 15) branching off from the main flow path 12. The main flow path 12 is equipped with a distribution thermometer 16 for detecting the temperature of the cooling water flowing through the main flow path 12. Each of the distribution paths 13, 14, and 15 is equipped with a distribution valve 17, 18, and 19 (first distribution valve 17, second distribution valve 18, and third distribution valve 19). Each of the distribution valves 17, 18, and 19 is a valve that opens and closes the corresponding distribution path 13, 14, and 15. Each of the distribution valves 17, 18, and 19 is, for example, a solenoid valve.

[0029] <Water storage section> Each of the water storage units 51, 52, and 53 stores cooling water dripped from the water spraying unit 3 via the distribution unit 4. Of the three water storage units 51, 52, and 53, the first water storage unit 51 is connected to the first distribution line 13. Of the three water storage units 51, 52, and 53, the second water storage unit 52 is connected to the second distribution line 14. Of the three water storage units 51, 52, and 53, the third water storage unit 53 is connected to the third distribution line 15.

[0030] Each of the water storage sections 51, 52, and 53 is equipped with a water level meter 21, 22, and 23 (first water level meter 21, second water level meter 22, and third water level meter 23). Each water level meter 21, 22, and 23 detects the amount of water stored in the corresponding water storage section 51, 52, and 53. Each of the water storage sections 51, 52, and 53 is equipped with a water storage thermometer 24, 25, and 26 (first water storage thermometer 24, second water storage thermometer 25, and third water storage thermometer 26). Each water storage thermometer 24, 25, and 26 detects the temperature of the cooling water stored in the corresponding water storage section 51, 52, and 53.

[0031] Each of the water storage sections 51, 52, and 53 is equipped with a bacterial component concentration meter 27, 28, and 29 (first bacterial component concentration meter 27, second bacterial component concentration meter 28, and third bacterial component concentration meter 29). Each bacterial component concentration meter 27, 28, and 29 detects the concentration of a predetermined bacterial component in the cooling water stored in the corresponding water storage section 51, 52, and 53. The bacterial component is, for example, Legionella bacteria.

[0032] <Dispatch Unit> The discharge unit 6 discharges the cooling water from each of the water storage units 51, 52, and 53 to the heat exchanger 2. The discharge unit 6 comprises three discharge passages 31, 32, and 33 (first discharge passage 31, second discharge passage 32, and third discharge passage 33) that are separately connected to the corresponding water storage units 51, 52, and 53, and a combined discharge passage 34 into which each of the discharge passages 31, 32, and 33 merge. The ends of the combined discharge passage 34 opposite to each of the discharge passages 31, 32, and 33 are connected to the heat exchanger 2.

[0033] Each of the discharge passages 31, 32, and 33 is provided with a discharge valve 36, 37, and 38 (first discharge valve 36, second discharge valve 37, and third discharge valve 38). Each of the discharge valves 36, 37, and 38 is a valve that opens and closes the corresponding discharge passage 31, 32, and 33. Each of the discharge valves 36, 37, and 38 is, for example, a solenoid valve. A pump 39 is provided in the combined discharge channel 34. The pump 39 sends cooling water to the heat exchanger 2.

[0034] <Supply section> The supply unit 7 supplies cooling water to each of the water storage units 51, 52, and 53 from a water source (not shown). The supply unit 7 comprises a source channel 40 extending from the water source, and three supply channels 41, 42, and 43 (first supply channel 41, second supply channel 42, and third supply channel 43) branching off from the source channel 40. The source channel 40 is equipped with a supply thermometer 47 for detecting the temperature of the cooling water flowing through the source channel 40.

[0035] The side of each supply channel 41, 42, and 43 opposite to the source channel 40 is connected to the corresponding water storage sections 51, 52, and 53, respectively. That is, of the three supply channels 41, 42, and 43, the first supply channel 41 is connected to the first water storage section 51. Of the three supply channels 41, 42, and 43, the second supply channel 42 is connected to the second water storage section 52. Of the three supply channels 41, 42, and 43, the third supply channel 43 is connected to the third water storage section 53.

[0036] Each of the supply passages 41, 42, and 43 is provided with a supply valve 44, 45, and 46 (first supply valve 44, second supply valve 45, and third supply valve 46). Each of the supply valves 44, 45, and 46 is a valve that opens and closes the corresponding supply passage 41, 42, and 43. Each of the supply valves 44, 45, and 46 is, for example, a solenoid valve.

[0037] The supply unit 7 includes a chemical injection unit 60 for introducing disinfectant into the cooling water. The chemical injection unit 60 includes a tank 64 filled with disinfectant, and chemical injection passages 61, 62, 63 (first chemical injection passage 61, second chemical injection passage 62, third chemical injection passage 63) connected to the tank 64 and each of the water storage units 51, 52, 53 and each of the supply passages 41, 42, 43. Each chemical injection passage 61, 62, 63 is provided with an injection valve 66, 67, 68 (first injection valve 66, second injection valve 67, third injection valve 68). Each injection valve 66, 67, 68 is a valve that opens and closes the corresponding chemical injection passage 61, 62, 63. Each injection valve 66, 67, 68 is, for example, a solenoid valve.

[0038] <Drainage section> The drainage section 5 drains the cooling water from each of the water storage sections 51, 52, and 53. The drainage section 5 comprises three drainage channels 71, 72, and 73 (first drainage channel 71, second drainage channel 72, and third drainage channel 73) that are separately connected to the corresponding water storage sections 51, 52, and 53, respectively, and a combined drainage channel 74 into which each of the drainage channels 71, 72, and 73 merges. The ends of the combined drainage channel 74 opposite to each of the drainage channels 71, 72, and 73 are connected to, for example, a drain tank (not shown).

[0039] Each of the drainage channels 71, 72, and 73 is provided with drainage valves 76, 77, and 78 (first drainage valve 76, second drainage valve 77, and third drainage valve 78), respectively. Each of the drainage valves 76, 77, and 78 is a valve that opens and closes the corresponding drainage channel 71, 72, and 73, respectively. Each of the drainage valves 76, 77, and 78 is, for example, a solenoid valve.

[0040] <Operation of the chilled water chiller> Next, the operation of the chilled water chiller 1 will be explained based on Figures 1 to 6. Figure 2 is a flowchart illustrating the operation of the chilled water chiller 1. In the following description, it is assumed that in the initial operation, valves 17-18, 36-38, 44-46, 66-68, and 76-78 are closed. Furthermore, in the following description, it is assumed that cooling water is already stored in each reservoir 51, 52, and 53 to an extent sufficient to operate the chilled water chiller 1 (above the lower limit water level). In addition, it is assumed that the fan 10 is driven.

[0041] <Main operation> The chilled water chiller 1 basically cools an object by circulating the cooling water stored in the first water reservoir 51 through the heat exchanger 2. In other words, the chilled water chiller 1 operates primarily using the first water reservoir 51. In other words, as shown in Figures 1 and 2, first the first distribution valve 17 is opened (step ST10). Next, open the first discharge valve 36 (step ST11). Next, the pump 39 is driven (step ST12).

[0042] As a result, the cooling water stored in the first water reservoir 51 is sent to the heat exchanger 2 (third cooling water delivery step). In the heat exchanger 2, heat exchange takes place between the heat of the cooling water and the object, and the object is cooled (step ST13). The cooling water heated in the heat exchanger 2 is sprayed onto the packing material 9 via the return channel 20 and the spray pipe 8. The cooling water sprayed onto the packing material 9 is cooled using the heat of vaporization and then dripped down to the distribution section 4. In the distribution section 4, the first distribution valve 17 is open, so the cooling water is returned to the first water reservoir 51. By repeating this circulation, the cooling of the object is promoted.

[0043] While the object is being cooled, the amount of water stored in the first water reservoir 51 gradually decreases due to the vaporization of the cooling water in the packing material 9. Therefore, a determination is made as to whether the amount of cooling water stored in the first water reservoir 51 (hereinafter referred to as the first water reservoir amount), as detected by the first water level gauge 21, is below the rated water level (Step ST14; First Water Level Determination Step). The rated water level refers to the lowest water level among the water levels desirable for operating the chilled water chiller 1, where the water level of the cooling water stored in each water storage section 51, 52, and 53 is the rated water level. The rated water level may be set as the lower limit water level, or it may be set as above the lower limit water level and below the upper limit water level. The upper limit water level refers to the maximum water level at which cooling water can be stored in each water storage section 51, 52, and 53.

[0044] Simultaneously with step ST14, a determination is made as to whether the temperature of the cooling water flowing through the return channel 20 (hereinafter referred to as the return channel water temperature), detected by the return channel thermometer 11, is equal to or greater than a predetermined upper temperature limit (step ST15).

[0045] Simultaneously with steps ST14 and ST15, a determination is made as to whether the concentration of a predetermined bacterial component in the cooling water of the first water reservoir 51 (hereinafter referred to as the bacterial concentration of the first water reservoir), as detected by the first bacterial component concentration meter 27, is equal to or greater than a predetermined upper limit of concentration (step ST16; bacterial concentration determination step).

[0046] If the determination in step ST14 is "No," meaning the water level in the first reservoir is higher than the rated water level, the determination in step ST14 is repeated. If the determination in step ST14 is "Yes," that is, if the water level in the first reservoir is lower than the rated water level, the first supply valve 44 is opened (step ST17). As a result, cooling water is supplied to the first reservoir 51 from the water source, and the main operation of the chilled water chiller 1 is completed.

[0047] On the other hand, if the determination in step ST15 is "No," that is, if the return channel water temperature is lower than a predetermined upper temperature limit, the temperature of the cooling water flowing through the source channel 12 of the distribution unit 4 detected by the distribution thermometer 16 (hereinafter referred to as the distribution water temperature) and the temperature of the cooling water flowing through the source channel 40 of the supply unit 7 detected by the supply thermometer 47 (hereinafter referred to as the supply water temperature) are compared (first temperature comparison step). Then, a determination is made as to whether the distribution water temperature is higher than the supply water temperature (step ST18). If the determination in step ST60 is "Yes," meaning the distribution water temperature is higher than the supply water temperature, then the supply water cooling system is started (step ST100).

[0048] <Water supply and cooling> Figure 3 is a flowchart showing the operation of water supply and cooling. As shown in Figure 3, in the feedwater cooling process, first, the temperature of the cooling water in the second water storage unit 52 detected by the second water storage thermometer 25 (hereinafter referred to as the second water storage unit temperature) is compared with the supply water temperature (first temperature comparison step). Then, a determination is made as to whether the second water storage unit temperature is higher than the supply water temperature (step ST101).

[0049] If the determination in step ST101 is "No," meaning the water temperature in the second reservoir is lower than the supply water temperature, the determination in step ST101 is repeated. If the determination in step ST101 is "Yes," that is, if the water temperature in the second water storage section is higher than the supply water temperature, a determination is made as to whether the amount of cooling water stored in the second water storage section 52 (hereinafter referred to as the amount of water in the second water storage section), as detected by the second water flow meter 22, is below the upper limit water level (step ST102; first water storage amount determination step).

[0050] If the determination in step ST102 is "Yes," that is, if the water level in the second water storage section is below the upper limit, the second supply valve 45 is opened (step ST103). As a result, cooling water is supplied to the second water storage section 52 from the water source (first cooling water supply process). If the determination in step ST102 is "No," that is, if the water level in the second reservoir is higher than the upper limit, then a determination is made as to whether the water level in the first reservoir is below the upper limit (step ST104; first reservoir level determination step).

[0051] If the determination in step ST104 is "No," meaning the water level in the first reservoir is higher than the upper limit, the determination in step ST104 is repeated. If the determination in step ST104 is "Yes," that is, if the water level is below the upper limit, the second distribution valve 18 is closed and the first distribution valve 17 is opened (step ST105). As a result, the cooling water dripped from the water spraying unit 3 is returned to the first water storage unit 51 via the distribution unit 4 (first cooling water return process).

[0052] Next, the first discharge valve 36 is closed and the second discharge valve 37 is opened (step ST106). As a result, the cooling water stored in the second water reservoir 52 is discharged to the heat exchanger 2 (first cooling water discharge step). By repeating this series of operations for feedwater cooling, the cooling of the object by the chilled water chiller 1 continues, while cooling water at a lower temperature (cooled) is stored in the first water reservoir 51 and the second water reservoir 52. With this, the feedwater cooling operation is completed.

[0053] On the other hand, as shown in Figure 2, if the determination in step ST18 is "No," that is, if the distribution water temperature is lower than the supply water temperature, circulating cooling is started (step ST200).

[0054] <Circulating cold storage> Figure 4 is a flowchart showing the operation of circulating cold storage. As shown in Figure 4, in circulating cold storage, first, the distribution water temperature and the second reservoir water temperature are compared (first temperature comparison step). Then, a determination is made as to whether the second reservoir water temperature is higher than the distribution water temperature (step ST201).

[0055] If the determination by step ST201 is "No," meaning the water temperature in the second reservoir is lower than the distribution water temperature, the determination by step ST201 is repeated. If the determination in step ST201 is "Yes," that is, if the water temperature in the second reservoir is higher than the distribution water temperature, a determination is made as to whether the water level in the second reservoir is below the upper limit (step ST202; first reservoir level determination step).

[0056] If the determination in step ST202 is "Yes," that is, if the water level in the second water reservoir is below the upper limit, the first distribution valve 17 is closed and the second distribution valve 18 is opened (step ST203). As a result, the cooling water dripped from the water spraying unit 3 is supplied (recirculated) to the second water reservoir 52 via the distribution unit 4 (second cooling water supply process). If the determination in step ST202 is "No," meaning the water level in the second reservoir is higher than the upper limit, then a determination is made as to whether the water level in the first reservoir is below the upper limit (step ST204; first reservoir level determination step).

[0057] If the determination by step ST204 is "No," meaning the water level in the first reservoir is higher than the upper limit, the determination by step ST204 is repeated. If the determination in step ST204 is "Yes," that is, if the water level is below the upper limit, the second distribution valve 18 is closed and the first distribution valve 17 is opened (step ST205). As a result, the cooling water dripped from the water spraying unit 3 is returned to the first water storage unit 51 via the distribution unit 4 (second cooling water return process).

[0058] Next, the first discharge valve 36 is closed and the second discharge valve 37 is opened (step ST206). As a result, the cooling water stored in the second water reservoir 52 is discharged to the heat exchanger 2 (second cooling water discharge step). By repeating this series of circulating cooling operations, the cooling of the object by the chilled water chiller 1 continues, while cooling water at a lower temperature (cooled) is stored in the first water reservoir 51 and the second water reservoir 52. With this, the circulating cooling operation is completed.

[0059] On the other hand, as shown in Figure 2, if the determination in step ST15 is "Yes," that is, if the return channel water temperature is above a predetermined temperature upper limit, a determination is made as to whether the water temperature in the second water storage section is lower than the cooling water temperature in the first water storage section 51 detected by the first water storage thermometer 24 (hereinafter referred to as the first water storage section water temperature) (step ST19; second temperature comparison step). A "Yes" result in step ST15 indicates that the cooling water in the first water reservoir 51 is insufficient to cool the object.

[0060] If the determination in step ST19 is "No," that is, if the water temperature in the first reservoir is lower than or equal to the water temperature in the second reservoir, the determination in step ST19 is repeated. If the determination in step ST19 is "Yes," that is, if the water temperature in the second reservoir is lower than the water temperature in the first reservoir, the cooling output is started (step ST300).

[0061] <Cold storage output> Figure 5 is a flowchart showing the operation of the thermal storage output. As shown in Figure 5, in the cooling output, first, it is determined whether the water level in the second reservoir is below the lower limit (Step ST301; Second reservoir level determination step). If the determination in step ST301 is "Yes," that is, if the water level in the second reservoir is below the lower limit, the determination in step ST301 is repeated.

[0062] If the determination in step ST301 is "No," that is, if the water level in the second water reservoir is higher than the lower limit, the first distribution valve 17 is closed and the second distribution valve 18 is opened (step ST302). As a result, the cooling water dripped from the water spraying unit 3 is returned to the second water reservoir 52 via the distribution unit 4 (first cooling water return process).

[0063] Next, the first discharge valve 36 is closed and the second discharge valve 37 is opened (step ST303). As a result, the cooling water stored in the second water reservoir 52 is discharged to the heat exchanger 2 (fourth cooling water discharge step). In other words, the cooling water in the second water reservoir 52, which is colder than the cooling water in the first water reservoir 51, is discharged to the heat exchanger 2. Therefore, heat exchange between the heat of the cooling water and the object is performed more efficiently in the heat exchanger 2, and the object is cooled rapidly. With this, the operation of the thermal storage output is completed.

[0064] On the other hand, as shown in Figure 2, if the determination in step ST16 is "No," that is, if the bacterial concentration in the first reservoir is lower than the predetermined upper limit of concentration, the determination in step ST16 is continued. If the determination in step ST16 is "Yes," meaning the bacterial concentration in the first reservoir is above a predetermined upper limit, the drainage operation is started (step ST400).

[0065] <Drainage operation> Figure 6 is a flowchart showing the operation of the drainage operation. As shown in Figure 6, in drainage operation, first, the first supply valve 44 is closed (step ST401). Next, the first discharge valve 36 is closed and the third discharge valve 38 is opened (step ST402). Next, the first distribution valve 17 is closed and the third distribution valve 19 is opened (step ST403).

[0066] As a result, the use of the first water reservoir 51 is completely stopped. The operation of the chilled water chiller 1 continues using the third water reservoir 53 instead of the first water reservoir 51. That is, the cooling water stored in the third water reservoir 53 is sent to the heat exchanger 2. The cooling water heated in the heat exchanger 2 is returned to the third water reservoir 53 via the spraying unit 3 and the distribution unit 4.

[0067] Next, the first water level gauge 21 is used to determine whether all of the cooling water stored in the first water reservoir 51 has been discharged (step ST404). Simultaneously with step ST404, a determination is made as to whether the amount of cooling water stored in the third water reservoir 53 (hereinafter referred to as the amount of water in the third water reservoir), as detected by the third water volume meter 23, is below the rated water level (step ST405).

[0068] If the determination in step ST404 is "No," meaning that not all of the cooling water stored in the first water reservoir 51 has been drained, the first drain valve 76 is opened (step ST406). This drains the cooling water from the first water reservoir 51 (drainage process). After this, the decision in step ST404 will be made again. If the determination in step ST404 is "Yes," that is, if all the cooling water stored in the first water reservoir 51 has been drained, the first drain valve 76 is closed (step ST407).

[0069] Next, a determination is made as to whether the water level in the first reservoir is above the lower limit (step ST408). If the determination in step ST408 is "No," that is, if the water level in the first reservoir is lower than the lower limit, the first supply valve 44 is opened and the first input valve 66 is opened (step ST409). As a result, cooling water is supplied to the first reservoir 51 from the water source (third cooling water supply step). Then, the cooling water in the first reservoir 51 is completely replaced.

[0070] Furthermore, disinfectant from tank 64 is introduced into the first water storage section 51 via the disinfectant input passage 61 (disinfectant input process). After this, the decision in step ST408 will be made again. If the determination in step ST408 is "Yes," that is, if the water level in the first reservoir is above the lower limit, the first discharge valve 36 is opened and the third discharge valve 38 is closed (step ST410).

[0071] Next, the first distribution valve 17 is opened and the third distribution valve 19 is closed (step ST411). As a result, the cooling water dripped from the water spraying unit 3 is returned to the first water storage unit 51 via the distribution unit 4. Next, a determination is made as to whether the water level in the first reservoir is below the rated water level (step ST412). If the determination by step ST412 is "No," meaning the water level in the first reservoir is higher than the rated water level, the determination by step ST412 is performed again.

[0072] If the determination in step ST412 is "Yes," that is, if the water level in the first reservoir is below the rated water level, the first supply valve 44 is opened (step ST413). This supplies cooling water from the water source to the first reservoir 51.

[0073] On the other hand, if the judgment by step ST405 is "No," that is, if the water level in the third reservoir is higher than the rated water level, the judgment by step ST405 will be continued. If the determination in step ST405 is "Yes," that is, if the water level in the third reservoir is below the rated level, the third supply valve 46 is opened (step ST414). This supplies cooling water from the water source to the third reservoir 53. This prepares the system to use the cooling water from the third reservoir 53 instead of the first reservoir 51 when the first reservoir 51 is performing a drainage operation. With this, the drainage operation is completed.

[0074] As described above, the chilled water chiller 1 comprises a water spraying unit 3, three water storage units 51, 52, and 53 for each water spraying unit 3, a distribution unit 4, a delivery unit 6, and a supply unit 7. Therefore, while the cooling water in one water storage unit 51, 52, or 53 is being replaced, the cooling of the object can be continued using the other water storage units 51, 52, and 53. By monitoring the temperature of the cooling water stored in each water storage unit 51, 52, and 53, it is possible to control the temperature of the cooling water by, for example, prioritizing the cooling of the cooling water in the water storage unit 51, 52, or 53 that has a relatively higher temperature. In this way, the number of bacteria in the cooling water in the water storage units 51, 52, and 53 can be effectively reduced without stopping the chilled water chiller.

[0075] Furthermore, the chilled water chiller 1 is equipped with a chemical injection unit 60. This allows for the automatic enhancement of the sterilization effect in the cooling water of each water reservoir 51, 52, and 53. As a result, the number of specific bacteria in the cooling water can be reduced even more effectively.

[0076] The operation of the chilled water chiller 1 includes a first temperature comparison step, a first water storage amount determination step, a first cooling water supply step, and a first cooling water recirculation step. This enables the operation of supply water cooling. As a result, the cooling water in each water storage section 51, 52, and 53 can be cooled efficiently, and the target object can be cooled efficiently. In addition, the temperature of the cooling water can be easily controlled.

[0077] Other operations of the chilled water chiller 1 include a first temperature comparison step, a first water storage amount determination step, a second cooling water supply step, and a second cooling water recirculation step. This enables circulating cooling. As a result, the cooling water in each water storage section 51, 52, and 53 can be cooled efficiently, and the target object can be cooled efficiently. Furthermore, the temperature of the cooling water can be easily controlled.

[0078] Other operations of the chilled water chiller 1 include a third cooling water delivery step, a second temperature comparison step, a second water storage amount determination step, and a fourth cooling water delivery step. This enables the operation of a stored cold output. As a result, it becomes possible to cool the target object efficiently.

[0079] Other operations of the chilled water chiller 1 include a bacterial concentration determination step, a drainage step, and a third cooling water supply step. This allows for drainage operation. Therefore, if the concentration of a predetermined bacterial component in the cooling water of the first water storage unit 51 exceeds the upper limit, the cooling water in the first water storage unit 51 can be quickly replaced. Thus, the predetermined bacteria in the cooling water can be quickly reduced. The third cooling water supply process includes a chemical injection process. This allows for a rapid enhancement of the sterilization effect of the cooling water, and further effective reduction of specific bacteria in the cooling water.

[0080] The present invention is not limited to the embodiments described above, but includes various modifications to the embodiments described above, without departing from the spirit of the invention.

[0081] For example, in the embodiment described above, the chilled water chiller 1 was described as having three water storage units 51, 52, and 53 for one water spraying unit 3. However, it is not limited to this, and one water spraying unit 3 may have two water storage units. In this case, the second water storage unit 52 and the third water storage unit 53 can be combined into one, so that the roles of both the second water storage unit 52 and the second water storage unit 53 are combined into one water storage unit. Furthermore, one water spraying unit 3 may have three or more water storage units.

[0082] In the above-described embodiment, the operation of the drainage operation was explained in the case where it is determined whether the bacterial concentration in the first reservoir is above a predetermined upper limit (step ST16). The case where the cooling water in the first reservoir 51 is replaced was also explained. However, the invention is not limited to this, and in the drainage operation, it is also possible to determine whether the concentration of a predetermined bacterial component in the cooling water of the second reservoir 52 (hereinafter referred to as the second reservoir bacterial concentration), detected by the second bacterial component concentration meter 28, is above a predetermined upper limit. Furthermore, in the drainage operation, it is also possible to determine whether the concentration of a predetermined bacterial component in the cooling water of the third reservoir 53 (hereinafter referred to as the third reservoir bacterial concentration), detected by the third bacterial component concentration meter 29, is above a predetermined upper limit. If the bacterial concentration in the second reservoir or the bacterial concentration in the third reservoir is above a predetermined upper limit, the drainage operation of the second reservoir 52 and the third reservoir 53 is performed in the same manner as the drainage operation of the first reservoir 51. During this time, cooling water from storage sections other than those 52 and 53, which are currently being drained, is sent to the heat exchanger 2.

[0083] In addition, for example, when the chilled water chiller 1 is used in cold climates, the cooling water in the second water storage section 52 and the third water storage section 53 may freeze due to the outside air. When the first water storage section 51 is used primarily, the cooling water is heated by the object via the heat exchanger 2, so the possibility of the first water storage section 51 freezing is low. Therefore, when the water temperature in the second water storage section and the temperature of the cooling water in the third water storage section 53 detected by the third water storage thermometer 26 approach the freezing point, it is possible to avoid freezing of the cooling water in the second water storage section 52 and the third water storage section 53 by switching from operation mainly using the first water storage section 51 to operation mainly using the second water storage section 52 and the third water storage section 53. [Explanation of Symbols]

[0084] 1…Cold water chiller 2...Heat exchanger (heat source) 3... Sprinkler unit 4...Distribution section 5…Drainage section 6... Sending section 7...Supply section 9…Filling material 51...First Water Reservoir (Water Reservoir) 52... Second Water Reservoir (Water Reservoir) 53... Third Water Reservoir (Water Reservoir) 60... Drug dispensing section

Claims

1. A water spraying unit cools the cooling water by spraying it onto the packing material, For each of the aforementioned water spraying units, there are multiple water storage units for storing the cooling water drained from the water spraying unit, A distribution unit that distributes the cooling water drained from one of the water spraying units to each of the water storage units, A dispensing unit that sends the cooling water from each of the water storage units to the heat source, Each of the water storage sections is supplied by a supply unit, A method for operating a chilled water chiller, comprising: A first temperature comparison step involves comparing the temperature of the cooling water in the water storage section, the temperature of the cooling water in the distribution section, and the temperature of the cooling water in the supply section. A first water level determination step involves separately determining whether the amount of cooling water stored in two of the aforementioned water storage sections is below the upper limit water level, The water storage section in which it is determined by the first temperature comparison step that the cooling water stored in the supply section is at a temperature higher than the temperature of the cooling water in the supply section is designated as the first high-temperature water storage section. The water storage section in which the water storage amount is determined to be below the upper limit level by the first water storage amount determination step is designated as a small amount water storage section. When the water storage section that is the first high-temperature water storage section and also the small-volume water storage section is designated as the first high-temperature small-volume water storage section, If the first temperature comparison step determines that the temperature of the cooling water in the supply unit is lower than the temperature of the cooling water in the distribution unit, and one of the two water storage units is the first high-temperature small-volume water storage unit, then the first cooling water supply step is to supply the cooling water from the supply unit to the first high-temperature small-volume water storage unit, A first cooling water supply step of supplying the cooling water from one of the two water storage sections to the heat source, The system includes, after the first cooling water supply step, a first cooling water recirculation step in which the cooling water is recirculated to the other of the two water storage units via the distribution unit, A method for operating a chilled water chiller, characterized by the features described above.

2. A water spraying unit cools the cooling water by spraying it onto the packing material, For each of the aforementioned water spraying units, there are multiple water storage units for storing the cooling water drained from the water spraying unit, A distribution unit that distributes the cooling water drained from one of the water spraying units to each of the water storage units, A dispensing unit that sends the cooling water from each of the water storage units to the heat source, Each of the water storage sections is supplied by a supply unit, A method for operating a chilled water chiller, comprising: A first temperature comparison step involves comparing the temperature of the cooling water in the water storage section, the temperature of the cooling water in the distribution section, and the temperature of the cooling water in the supply section. A first water level determination step involves separately determining whether the amount of cooling water stored in two of the aforementioned water storage sections is below the upper limit water level, The water storage section in which it is determined by the first temperature comparison step that the cooling water stored in the distribution section is at a temperature higher than the cooling water temperature in the distribution section is designated as the second high-temperature water storage section. The water storage section in which the water storage amount is determined to be below the upper limit level by the first water storage amount determination step is designated as a small amount water storage section. When the water storage section that is the second high-temperature water storage section and the small-volume water storage section is designated as the second high-temperature small-volume water storage section, If the first temperature comparison step determines that the temperature of the cooling water in the distribution unit is higher than the temperature of the cooling water in the supply unit, and one of the two water storage units is the second high-temperature small-volume water storage unit, then a second cooling water supply step is performed to supply the cooling water from the distribution unit to the second high-temperature small-volume water storage unit. A second cooling water supply step, which supplies the cooling water from one of the two water storage sections to the heat source, The system includes, after the second cooling water supply step, a second cooling water recirculation step in which the cooling water is recirculated to the other of the two water reservoirs via the distribution unit, A method for operating a chilled water chiller, characterized by the features described above.

3. A water spraying unit cools the cooling water by spraying it onto the packing material, For each of the aforementioned water spraying units, there are multiple water storage units for storing the cooling water drained from the water spraying unit, A distribution unit that distributes the cooling water drained from one of the water spraying units to each of the water storage units, A dispensing unit that sends the cooling water from each of the water storage units to the heat source, Each of the water storage sections is supplied by a supply unit, A method for operating a chilled water chiller, comprising: A third cooling water delivery step in which the delivery unit delivers the cooling water from one of the plurality of water storage units to the heat source, If, during the third cooling water supply process, the temperature of the cooling water heated by the heat source exceeds a predetermined upper temperature limit, a second temperature comparison step is performed to compare the temperature of the cooling water in the water reservoir where the third cooling water supply process is being carried out with the temperature of the cooling water in one of the other water reservoirs where the third cooling water supply process is not being carried out. A second water level determination step for determining whether the amount of cooling water stored in the other water storage section is below the lower limit water level, If the second temperature comparison step determines that the temperature of the cooling water in the water storage unit other than the one in which the third cooling water supply step is performed is lower than the temperature of the cooling water in the other water storage unit, and if the amount of cooling water in the other water storage unit is determined to be higher than the lower limit water level, then the supply unit sends the cooling water from the other water storage unit to the heat source in a fourth cooling water supply step, Having, A method for operating a chilled water chiller, characterized by the features described above.

4. A bacterial concentration determination step for determining whether the concentration of a predetermined bacterial component in the cooling water in each of the water storage sections is above an upper limit, A drainage step in which the cooling water from the water reservoir is drained if the concentration of bacterial components is determined to be above the upper limit value in the bacterial concentration determination step, A third cooling water supply step is performed in which, after the drainage step, the cooling water is supplied from the supply unit to the water storage area where the drainage step has been performed. Having, A method for operating a chilled water chiller according to any one of claims 1 to 3, characterized by the features described above.

5. The third cooling water supply step includes a chemical addition step of adding a disinfectant to the cooling water. The method for operating a chilled water chiller according to feature 4.

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