State evaluation method of cooling tower and cooling tower system

Abstract

To provide a state evaluation method of a cooling tower for accurately calculating the cooling tower efficiency of the cooling tower by evaluating a state of each cell, in the cooling tower constituted of the plurality of cells, and a system for supplying a water treatment agent when performance is deteriorated.SOLUTION: A state evaluation method of a cooling tower comprises: a first measurement step of measuring current values, power or frequencies of a cooling tower 5 having a plurality of cells 51 having fans 52 for lowering a temperature of cooling water, and the fans 52 of a heat exchanger 6; a second measurement step of measuring an ambient temperature, relative humidity and atmospheric pressure in an installation environment of the cooling tower 5; and a calculation step having the first and second measurement steps, and of continuously calculating cooling tower efficiency at each cell 51 on the basis of an outlet temperature of the cooling water before passing through the heat exchanger 6 from an outlet of a conduit 53, an inlet temperature of the cooling water up to an entrance of the conduit 53 after passing through the heat exchanger 6, and measurement values in the plurality of cells 51. A cooling tower system includes a water treatment agent addition device for providing a water treatment agent when performance is deteriorated.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cooling tower condition evaluation method and a cooling tower system. [Background technology]

[0002] Facility plants such as power plants, chemical plants, and air conditioning plants generate or recover large amounts of heat while operating. In order to control this large amount of heat and operate the plant continuously and stably, the plant is operated by repeatedly using cooling water, etc., which is composed of various fluids such as water. It is known that the performance of the cooling tower in the cooling tower system deteriorates over time, and in order to operate the plant stably, it is desirable to always know the degree of deterioration. Conventionally, cooling towers are installed with multiple cells, each with its own fan, connected together so that each cell can operate independently, and the number of fans is controlled according to the outside air conditions and operating load. Although each cell is installed adjacent to the others, the degree of performance degradation varies depending on the amount of sunlight, the surrounding environment, the layout of the water supply piping, etc., so it is desirable to understand the degree of performance degradation for each cell. However, until now, the performance degradation state of a cooling tower system has often been evaluated as a whole cooling tower with connected cells, without incorporating an evaluation of each individual cell.

[0003] In the case of open-type cooling towers, in addition to performance degradation over time, if the cooling tower becomes dirty and the filler becomes clogged, the ventilation volume will decrease and the evaporation of the circulating water will be hindered. In addition, if the upper sprinkler tank becomes clogged, the water will be sprayed unevenly, causing the balance between the water volume and the air volume to be disrupted locally, and the designed evaporation volume may not be achieved. In the case of a closed cooling tower, if the heat exchange tube becomes dirty, the heat exchange efficiency between the sprayed water and the circulating water decreases. If the cooling tower becomes dirty in this way, the operating time of the cooling tower fan required to maintain the same water temperature as before the dirt was removed will be longer, causing energy loss. In addition, even if the fan operates continuously, the specified water temperature may not be obtained and the supply water temperature may rise. The rise in the supply water temperature causes the problem of increased power consumption of the chiller. On the other hand, measures to prevent fouling of cooling towers include automatic blower control for cooling water concentration by monitoring the electrical conductivity of the cooling water, and injection of water treatment agents into the cooling water at predetermined concentrations to suppress slime and scale.

[0004] For example, the cooling tower condition evaluation device described in Patent Document 1 is a method for evaluating the deterioration of the performance of a wet cooling tower based on the temperature of water fed into the wet cooling tower, the temperature of water discharged from the wet cooling tower, and the wet-bulb temperature of the atmosphere, but does not mention evaluation of individual cells. Furthermore, since this condition evaluation device does not mention a means for grasping the start and stop of the fan, it is not possible to accurately evaluate the cooling tower performance of a cooling tower whose fan operating state is constantly changing. Even if the starting and stopping of the fan is taken into consideration, it can be assumed that there is no draft in the cell where the fan is stopped, and there is no change in the temperature of the cooling water. However, actual operating data of a cooling tower has revealed that draft occurs even in a cell where the fan is stopped, and the temperature of the cooling water drops.

[0005] In view of the above, in order to grasp the condition of the cooling tower more accurately, it is desirable to evaluate the performance of each cell individually, and furthermore, it is desirable to evaluate the performance after correcting for the ventilation within the cells where the fans are stopped. Furthermore, if a deterioration in the performance of the cooling tower is discovered, it is desirable to quickly restore it by injecting a water treatment agent into the cooling water, and then to implement stable, energy-saving operation by understanding the condition of the cooling tower and evaluating the performance of each cell individually. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-100662 A Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the present invention provides a cooling tower condition evaluation method that accurately calculates the performance of a cooling tower that is composed of a plurality of cells and operates by turning on and off fans that blow air within each cell, by continuously evaluating the condition of each cell. Furthermore, an object of the present invention is to provide a cooling system that applies a cooling tower condition evaluation method that accurately calculates the performance of a cooling tower. Another object of the present invention is to provide a cooling tower condition evaluation method that accurately calculates the performance of a cooling tower in order to quickly restore the performance of the cooling tower when the performance of the cooling tower has deteriorated. Furthermore, the present invention provides a cooling tower system that applies a cooling tower condition evaluation method that accurately calculates the performance of a cooling tower in order to quickly restore the performance of the cooling tower when the performance of the cooling tower deteriorates. [Means for solving the problem]

[0008] The features of the embodiments of the present invention will be described below. (1) A cooling tower comprising: a plurality of cells each having a fan for lowering the temperature of the cooling water by evaporating a portion of the cooling water by blowing air; a pipeline connected to the plurality of cells or a single cell and configured to externally circulate the cooling water, the pipeline being configured so that the cooling water is supplied from an inlet of the pipeline and discharged from an outlet of the pipeline; and a heat exchanger disposed midway along the path from the outlet to the inlet of the pipeline of the cell for heating the cooling water, the cooling tower efficiency of the cooling tower being calculated. A condition evaluation method for a cooling tower, comprising: a first measurement step of measuring an outlet temperature of the cooling water from the outlet of the pipeline before passing through the heat exchanger, an inlet temperature of the cooling water from after passing through the heat exchanger to the inlet of the pipeline, and a current value, power or frequency of the fans of each of the plurality of cells; a second measurement step of measuring an outside air temperature, relative humidity and atmospheric pressure in an installation environment of the cooling tower; and a calculation step of continuously calculating the cooling tower efficiency for each of the cells based on the measured values ​​in the first and second measurement steps. (2) The cooling tower condition evaluation method described in (1), further comprising a correction step of calculating the amount of ventilation generated by natural convection in a cell where operation of the fan has been stopped or by operation of a fan in an adjacent cell from the temperature of the cooling water at the inlet of the cooling tower and the cooling water temperature of any one of the cells, and correcting the cooling tower efficiency. (3) The cooling tower condition evaluation method according to (2), further comprising a cell calculation step of calculating the cooling tower efficiency of each cell of the cooling tower based on the previously recorded cooling tower efficiency of the cell and the calculated cooling tower efficiency of the cooling tower. (4) The cooling tower condition evaluation method according to (3), further comprising a recording step of calculating and recording the cooling tower efficiency of each cell each time the cell switches operation.

[0009] (5) A plurality of cells each having a fan that reduces the temperature of the cooling water by evaporating a portion of the cooling water by blowing air; a cooling tower including a pipeline connected to the plurality of cells or a single cell and configured to externally circulate the cooling water, the pipeline being configured such that the cooling water is supplied from an inlet of the pipeline and is discharged from an outlet of the pipeline; a heat exchanger disposed at a position midway along the path of the cooling water from the outlet to the inlet of the pipeline of the cell, the heat exchanger heating the cooling water, The cooling tower condition evaluation method includes: a first measurement step of measuring an outlet temperature of the cooling water from the outlet of the pipe before passing through the heat exchanger, an inlet temperature of the cooling water from after passing through the heat exchanger to the inlet of the pipe, and a current value, power, or frequency of a fan of each of the plurality of cells; A second measurement step of measuring an outside air temperature, a relative humidity, and an atmospheric pressure in an installation environment of the cooling tower; A calculation step of continuously calculating the cooling tower efficiency for each of the cells based on the measured values ​​in the first and second measurement steps; an addition step of adding a water treatment agent to the cooling water based on the cooling tower efficiency calculated in the calculation step. (6) The cooling tower condition evaluation method includes the steps of: The cooling tower condition evaluation method according to (5), wherein after the adding step, the cooling tower efficiency is continuously calculated for each cell by the calculation step based on the measured values ​​in the first and second measurement steps. (7) The cooling tower condition evaluation method includes the steps of: a correction step of calculating an amount of ventilation generated by natural convection in the cell where the operation of the fan has been stopped or by operation of the fan in the adjacent cell from a temperature of the cooling water at an inlet of the cooling tower and a cooling water temperature in any one of the cells, and correcting the cooling tower efficiency; The cooling tower condition evaluation method according to (6), wherein the adding step adds the water treatment agent to the cooling water based on the cooling tower efficiency corrected in the correcting step. (8) The cooling tower condition evaluation method includes the steps of: A cell calculation step of calculating a cooling tower efficiency of each cell of the cooling tower based on a previously recorded cooling tower efficiency of the cell and a calculated cooling tower efficiency of the cooling tower, The cooling tower state evaluation method according to (6), wherein the adding step adds the water treatment agent to the cooling water based on the cooling tower efficiency calculated in the cell calculation step. (9) The cooling tower condition evaluation method includes the steps of: The method for evaluating a state of a cooling tower according to (7) or (8), wherein the adding step adds the water treatment agent when the cooling tower efficiency is lower than a predetermined set value. (10) The cooling tower condition evaluation method includes the steps of: The cooling tower state evaluation method according to (7) or (8), wherein the adding step adds a predetermined amount of the water treatment agent based on a difference between the cooling tower efficiency and a predetermined set value.

[0010] (11) A cooling tower system comprising: a plurality of cells each having a fan for lowering a temperature of the cooling water by evaporating a portion of the cooling water by blowing air; a pipeline connected to the plurality of cells or a single cell and configured to circulate the cooling water externally, the pipeline being configured so that the cooling water is supplied from an inlet of the pipeline and discharged from an outlet of the pipeline; and a heat exchanger disposed midway along the path from the outlet of the pipeline to the inlet of the cell for heating the cooling water, the cooling tower system calculating a cooling tower efficiency of the cooling tower, the cooling tower system comprising: a first measuring means for measuring an outlet temperature of the cooling water from the outlet of the pipeline to before passing through the heat exchanger, an inlet temperature of the cooling water from after passing through the heat exchanger to the inlet of the pipeline, a current value, power or frequency of the fans of each of the plurality of cells; a second measuring means for measuring an outside air temperature, relative humidity and atmospheric pressure in an installation environment of the cooling tower; and a calculating means for continuously calculating the cooling tower efficiency for each of the cells based on the measured values ​​of the first and second measuring means. (12) The cooling tower system described in (11), wherein the calculation means calculates the amount of ventilation generated by natural convection in the cell where the operation of the fan has been stopped or by the operation of the fan of an adjacent cell from the temperature of the cooling water at the inlet of the cooling tower and the temperature of the cooling water in the lower water tank of any one of the cells, and corrects the cooling tower efficiency. (13) The cooling tower system according to (12), wherein the calculation means calculates the cooling tower efficiency of each cell of the cooling tower based on a previously recorded cooling tower efficiency of the cell and the calculated cooling tower efficiency of the cooling tower. (14) The cooling tower system according to (13), wherein the calculation means calculates and records the cooling tower efficiency of each cell each time the cell switches operation. (15) The cooling tower system according to (11), wherein the calculation means is connected to a first measurement means and a second measurement means via a communication means.

[0011] (16) A plurality of cells each having a fan for lowering the temperature of the cooling water by evaporating a portion of the cooling water by blowing air; a cooling tower including a pipeline connected to the plurality of cells or a single cell and configured to externally circulate the cooling water, the pipeline being configured such that the cooling water is supplied from an inlet of the pipeline and is discharged from an outlet of the pipeline; a heat exchanger that is disposed at a position midway along the path of the cooling water from the outlet to the inlet of the pipeline of the cell and that cools the cooling water; A water treatment agent addition device that adds a water treatment agent to the cooling water, The cooling system comprises: a first measuring means for measuring an outlet temperature of the cooling water from the outlet of the pipe before passing through the heat exchanger, an inlet temperature of the cooling water from after passing through the heat exchanger to the inlet of the pipe, and a current value, power, or frequency of a fan of each of the plurality of cells; A second measuring means for measuring an outside air temperature, a relative humidity, and an atmospheric pressure in an installation environment of the cooling tower; A calculation means for continuously calculating the cooling tower efficiency for each of the cells based on the measured values ​​in the first and second measurement means; A cooling tower system comprising: a water treatment agent adding means for adding the water treatment agent to the cooling water based on the cooling tower efficiency calculated by the calculation means; and a control means for controlling the water treatment agent adding means. (17) The cooling tower system according to (16), wherein after the adding step, the cooling tower system continuously calculates the cooling tower efficiency for each cell by the calculation step based on the measured values ​​in the first and second measurement steps. (18) The cooling tower system described in (16), wherein the control means calculates the amount of ventilation generated by natural convection in a cell where operation of the fan has been stopped or by operation of a fan in an adjacent cell from the temperature of the cooling water at the inlet of the cooling tower and the cooling water temperature of any one of the cells, and controls the calculation means which corrects the cooling tower efficiency. (19) The cooling tower system according to (16), wherein the control means controls the calculation means having a cell calculation step of calculating the cooling tower efficiency of each cell of the cooling tower based on a previously recorded cooling tower efficiency of the cell and a calculated cooling tower efficiency of the cooling tower. (20) The control means adds the water treatment agent when the cooling tower efficiency is lower than a predetermined set value. The above The cooling tower system according to (18) or (19), wherein the addition step is controlled. (21) The cooling tower system according to (18) or (19), wherein the control means controls the addition process of adding a predetermined water treatment agent based on a difference between the cooling tower efficiency and a predetermined set value. Effect of the Invention

[0012] According to the present invention, a cooling tower condition evaluation method for accurately calculating the cooling tower efficiency of a cooling tower that is composed of a plurality of cells and in which fans that blow air within each cell operate intermittently by evaluating the condition of each cell can be provided, and a cooling tower system that uses the same can be provided. In addition, according to the present invention, a cooling tower condition evaluation method can be provided that supplies a water treatment agent according to the performance state of the cooling tower and quickly restores the deterioration of the cooling tower efficiency, and a cooling tower system using the same can be provided. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing an embodiment of a cooling tower condition evaluation method of the present invention. [Diagram 2] FIG. 1 is a diagram showing an embodiment of a cooling tower condition evaluation method of the present invention. [Diagram 3] FIG. 1 is a flowchart illustrating an embodiment of a cooling tower state evaluation method of the present invention. [Figure 4] FIG. 1 is a flowchart illustrating an embodiment of a cooling tower state evaluation method of the present invention. [Diagram 5] FIG. 1 is a flowchart illustrating an embodiment of a cooling tower state evaluation method of the present invention. [Figure 6] FIG. 1 is a flowchart illustrating an embodiment of a cooling tower state evaluation method of the present invention. [Figure 7] FIG. 1 is a diagram showing an embodiment of a cooling tower system using the cooling tower condition assessment method of the present invention. [Figure 8] FIG. 1 is a diagram showing an embodiment of a cooling tower system using the cooling tower condition assessment method of the present invention. [Figure 9] This is a graph showing the cooling tower efficiency under experimental conditions (1), (2), and (3) from February 1st to 28th, and the period during which changes occurred in the number of operating fans. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes an embodiment of the present invention, but the following description is merely an example of an embodiment of the present invention and does not limit the scope of the claims.

[0015] The cooling tower condition evaluation method of the present invention is a cooling tower comprising a plurality of cells each having a fan that lowers the temperature of the cooling water by evaporating a portion of the cooling water by blowing air, a pipeline connected to a plurality of or a single cell and configured to circulate the cooling water externally, the pipeline being configured so that the cooling water is supplied from an inlet of the pipeline and discharged from an outlet of the pipeline, and a heat exchanger arranged midway along the way from the outlet of the pipeline to the inlet of the cell and heating the cooling water, and the cooling tower condition evaluation method of the present invention calculates the cooling tower efficiency of the cooling tower, the method comprising the steps of: a first measurement step of measuring the outlet temperature of the cooling water from the outlet of the pipeline before passing through the heat exchanger, an inlet temperature of the cooling water from after passing through the heat exchanger to the inlet of the pipeline, and a current value, power or frequency of the fans of each of the plurality of cells; a second measurement step of measuring the outside air temperature, relative humidity and atmospheric pressure in the installation environment of the cooling tower; and a calculation step of continuously calculating the cooling tower efficiency for each cell based on the measured values ​​in the first and second measurement steps.

[0016] FIG. 1 is a diagram showing one embodiment of the cooling tower condition evaluation method of the present invention. The cooling facility 3 in the cooling tower system for implementing the cooling tower state evaluation method of the present invention includes a control device 4, a cooling tower 5, a circulation pump 55 for circulating cooling water, and a heat exchanger 6. The cooling tower 5 includes a plurality of cells 511, 512, 513, ..., 51n (hereinafter, collectively referred to as "cells 51"; the same applies below). The cells 51 include fans 521, 522, 523, ..., 52n. Each cell 51 includes a filler that plays a role of increasing the contact efficiency between the cooling water and the air, and a water tank that directly contacts the cooling water. The cells 51 include electricity measuring means 541, ..., 54n that measure the current value, power, or frequency of the electricity sent to the fan 52, and the pipe 53 that circulates the cooling water includes a first measuring means including an inlet temperature measuring means (T1) 421 that measures the water temperature at the inlet of the cooling tower, an outlet temperature measuring means (T2) 422 that measures the water temperature at the outlet of the cooling tower, and a cell outlet temperature measuring means (T3) 423 that measures the water temperature at the outlet of the cell 51. Further, a second measuring means is provided, which includes an environment measuring means 424 for measuring the outside air temperature, relative humidity, and atmospheric pressure in the installation environment of the cooling tower 5.

[0017] The control device 4 has a control unit 41 that controls the amount of electricity sent to the fan 52 and the amount of water of the circulation pump 55. The control unit 41 also has a function of recording, as data, the measured values ​​measured by the first measuring means having the electricity measuring means 54, the inlet temperature measuring means (T1) 421, the outlet temperature measuring means (T2) 422, and the cell outlet temperature measuring means (T3) 423, and the second measuring means having the environment measuring means 424 of the outside air temperature, relative humidity, atmospheric pressure, etc., where the cooling tower 5 is installed, via the receiving unit 42. Using the measured values ​​from the data received by the receiving unit 42, the control unit 41 calculates the state of the cooling tower 5 as a cooling efficiency by the calculating means provided in the control unit 41, and performs a state evaluation method for evaluating the state of the cooling tower. Furthermore, although not shown, the control device 4 is connected to other devices and systems, such as an input device and a communication means such as the Internet.

[0018] Conventional cooling tower status evaluation methods do not mention a means for grasping the start and stop of the fan 52, so that accurate evaluation of cooling tower efficiency has not been possible for cooling towers 5 in which the operation state of the fan 52 constantly changes. Even if the start and stop of the fan 52 is taken into consideration, it is assumed that there is no draft in the cell 51 in which the fan 52 is stopped, and there is no change in the temperature of the cooling water. However, in reality, even in the cell 51 in which the fan 52 is stopped, drafts occur due to the convection of the surrounding air and the operation of the fan 52 of the adjacent cell 51, and the temperature of the cooling water drops. In particular, in winter when the wet-bulb temperature drops, it has been found that the cooling tower efficiency is overestimated if this drop in water temperature is ignored when calculating the cooling tower efficiency. Furthermore, since the degree of performance degradation often differs for each cell 51 depending on the installation environment of the cooling tower 5, it is desirable to evaluate the performance of the cooling tower 5 on a cell-by-cell basis.

[0019] The cooling tower condition evaluation method of the present invention further includes an addition step of adding a water treatment agent to the cooling water based on the cooling tower efficiency calculated in the calculation step.

[0020] FIG. 2 is a diagram showing one embodiment of the cooling tower condition evaluation method of the present invention. The cooling tower condition evaluation method of the present invention has a water treatment agent addition means for carrying out an addition step of adding a water treatment agent to cooling water. As shown in FIG. 2, the water treatment agent addition means has a water treatment agent addition device 7. Although not shown, the water treatment agent addition device 7 has a water treatment agent tank for storing the water treatment agent and a transport pump for transporting the water treatment agent from the water treatment agent tank. The water treatment agent is not limited to being solid or liquid. The transport pump for transporting the water treatment agent can add the water treatment agent at any point in the storage tank, the circulation path, or the make-up water path. When the water treatment agent to be added is a solid water treatment agent, the method of adding it to the cooling tower 5 and the pipeline 53 is not particularly limited, but a method of immersing the water treatment agent in the cooling water or a method of bringing a part of the water treatment agent into contact with the cooling water is preferable. When the water treatment agent is a liquid, any of a method using a tube pump, a method using a bellows pump, a method of adding the water treatment agent by gravity without using a transport pump, and the like is preferable.

[0021] Examples of the water treatment agent include slime control agents and scale inhibitors. The components of the water treatment agent are not particularly limited, but an oxidizing agent is preferable, and a chlorine agent is particularly preferable. Furthermore, since free chlorine agents are highly corrosive and may damage the cooling tower 5, it is more preferable that the water treatment agent contains combined chlorine.

[0022] Slime control agents are water treatment agents that suppress the sticky muddy dirt that accumulates in water supply and drainage facilities, equipment, and pipes due to Legionella bacteria. The intervals between doses are based on the period during which the bactericidal effect lasts, and vary depending on the concentration and the season of use. Slime control agents act on the surface of slime, reducing the number of Legionella bacteria and preventing them from adhering to and multiplying in pipes. Moreover, a scale inhibitor is a water treatment agent that removes water-insoluble oxides that have accumulated in water supply and drainage facilities, equipment, and piping. If they crystallize and adhere inside piping equipment, etc., they are very difficult to remove, causing problems with water supply and drainage. Examples of scale inhibitors include phosphates such as orthophosphoric acid, polymerized phosphoric acid, and phosphonic acid, acrylic acid polymers and copolymers, and maleic acid polymers and copolymers. More specifically, examples of scale inhibitors include polymers having carboxylic acid units, phosphonic acid, and polyphosphates.

[0023] The cooling tower condition evaluation method of the present invention also includes a control means for controlling the addition process of adding a water treatment agent. As the control means, as shown in FIG. 2, it is provided in the control unit 41 in the control device 4. The control unit 41 of the control device 4 is composed of a microcomputer and electronic circuits, which include, for example, a calculation means such as a CPU that operates a program, and a storage means such as a ROM that stores the program and the calculation results, and uses the measured value received by the receiving unit 42 to implement a condition evaluation method in which the calculation means provided in the control unit 41 evaluates the condition of the cooling tower 5. Furthermore, the control device 4 has a function of evaluating the condition of the cooling tower 5 and adjusting the type and amount of water treatment agent to be added to the cooling water of the cooling tower 5. Furthermore, the control unit 41 controls the water treatment agent addition device 7 to add the water treatment agent to the cooling tower 5, the pipe 53, etc.

[0024] The total amount of cooling water in the cooling tower 5 decreases due to evaporation during cooling in the cooling tower 5. The amount of cooling water also decreases due to scattering when supplied to the cooling tower 5. When this decreased amount of cooling water is replenished, a water treatment agent is also added. In this way, the water treatment agent is always added by the water treatment agent adding device 7. However, the decrease and fluctuation of the cooling water is not uniform, and furthermore, the cooling tower efficiency decreases with the deterioration of the cooling tower 5 and clogging of the cells 51 due to fouling caused by the use over time, and deterioration of the cooling equipment 3 due to fouling of the heat exchanger 6, etc. Therefore, the cooling tower condition evaluation method of the present invention includes an addition step of determining the type and amount of water treatment agent to be added based on the cooling tower efficiency calculated by the cooling tower condition evaluation method, and adding the water treatment agent to prevent not only the fluctuation of the cooling water but also the deterioration and fouling of the cooling tower 5.

[0025] FIG. 3 is a flowchart illustrating the cooling tower state evaluation method of the present invention. First, the cooling tower efficiency of the cells 51 constituting the cooling tower 5 is calculated in accordance with the cooling capacity test method in JIS B 8609, and is recorded in the control device 4 equipped with the control unit 41 having a storage device such as a memory (not shown) (step S1). Note that the cooling tower efficiency refers to the current capacity of the cooling tower 5, and specifically, refers to the ratio of the current cooling capacity to the design capacity. The test method in JIS B 8609 is to operate the cooling equipment 3 specified in the standard and use the results to determine the water temperature range and standard cooling capacity when the inlet water temperature and inlet air wet-bulb temperature are the standard design temperatures.

[0026] Next, any or all of the fan frequency, current value, and power of each cell 51 is recorded in the control device 4, and at the same time, it is confirmed whether the fan 52 is operating (step S2). In step S2, it is determined whether the fans 52 in all cells 51 are operating or whether there is at least one cell 51 with a fan 52 that is not operating.

[0027] If it is determined that at least one fan 52 is not operating, the ventilation volume in the cell where the fan 52 is not operating is calculated from the temperature difference (T1-T3) in the cell where the fan 52 is stopped, in accordance with the JIS B 8609 standard, by applying it to calculating the cooling tower efficiency (step S3). The cooling tower efficiency is calculated from the ratio of the design temperature difference (the temperature difference between the inlet and outlet of the cooling tower when the design cooling capacity is exerted) to the "actual inlet and outlet temperature difference" under certain operating conditions of the target cooling tower. In addition, since the design temperature difference varies depending on the state of the outside air, it is necessary to measure the outside air temperature, relative humidity, and atmospheric pressure and grasp the physical state of the surrounding air. Furthermore, the cooling tower efficiency is greatly influenced not only by the weather conditions of the surrounding environment, but also by the ventilation volume, which is the flow of air around the cells and the cooling tower. This is because cooling water flows to all the cells 51 installed in the cooling tower 5 even if the fan 52 is not operating. Even if the fan 52 is not operating, the surrounding air flows naturally and cools the cooling water that falls naturally within the cell or flows down through the filler provided in the cell, or the cooling water in the water tank. Furthermore, the effect on cooling of the cell 51 varies greatly depending on the temperature of the air, for example, between the outdoor air temperature in summer and the outdoor air temperature in winter. Therefore, in step S3, the effect on the cooling water in the cell 51 that is not operating is calculated as the ventilation volume. When there are multiple cells 51 that are not operating, the ventilation volume of each cell 51 can be calculated in a similar manner.

[0028] Next, in the cooling tower condition evaluation method of the present invention, the cooling tower efficiency of the operating cells 51 is corrected by subtracting the ventilation volume of the non-operating cells 51 during the calculation process, and the cooling tower efficiency of the operating cells 51 is continuously calculated (step S4). Here, what is calculated is the average value of the cooling tower efficiencies of the cells 51 having the operating fans 52. Furthermore, step S4 includes a correction process of calculating the ventilation volume in the non-operating cells 51 and correcting the cooling tower efficiency. The correction can be obtained by back-calculating the contribution of the non-operating cells 51 to the cooling tower outlet temperature (T2) in the difference between the cooling water inlet temperature (T1) and the cell outlet temperature (T3) to the ventilation volume.

[0029] Conventionally, the cooling tower efficiency has been calculated by including the inoperative cells 51 in the calculation of the cooling tower efficiency, so the cooling tower efficiency of the cooling tower 5 as a whole is small. Conversely, if the cooling tower efficiency is calculated using only the operating cells 51 without considering the effect of the inoperative cells 51 on the decrease in the cooling water temperature, the cooling tower efficiency will be large. Therefore, a cooling tower condition evaluation method that does not include a correction step of calculating the ventilation volume in a cell 51 that is not in operation and correcting the cooling tower efficiency cannot accurately calculate the cooling tower efficiency including the cell 51. In contrast, the cooling tower condition evaluation method of the present invention can accurately calculate the cooling tower efficiency of a cooling tower 5 consisting of operating cells 51 by correcting the contribution of inoperating cells 51 to the cooling water of the cooling tower 5 in a correction process.

[0030] FIG. 4 is a flowchart illustrating the cooling tower state evaluation method of the present invention. The cooling tower condition evaluation method of the present invention calculates the cooling tower efficiency of the cooling tower 5 consisting of the operating cells 51 (step S4). Furthermore, the cooling tower condition evaluation method of the present invention determines whether the average value of the calculated cooling tower efficiency is higher than a predetermined set value (step S5). In step S5, when it is determined that the average value of the cooling tower efficiency is higher than the predetermined set value (step S5 YES), the addition of the water treatment agent is not actively carried out, but the water treatment agent may be added so that the concentration of the water treatment agent decreases due to evaporation and scattering of the cooling water to the normal set concentration. After the water treatment agent is added, the cooling tower condition evaluation method can be ended (END).

[0031] On the other hand, when it is determined that the cooling tower efficiency is lower than the predetermined set value (step S5 NO), the water treatment agent is added at an increased amount than usual so that the water treatment agent reaches a normal set concentration in order to recover the cooling tower efficiency (step S6). Here, the type and amount of water treatment agent to be added are determined based on the cooling tower efficiency calculated by the cooling tower 5 state evaluation method, and the water treatment agent is added to prevent not only fluctuations in the cooling water but also deterioration and fouling of the cooling tower 5. In this case, it is preferable to determine in advance the amount of addition that is increased compared to the normal case, or the type of water treatment agent to be added. In particular, it is preferable to set multiple threshold values ​​of cooling tower efficiency and multiple amounts of water treatment agent to be added. Alternatively, it is also possible to add another water treatment agent in addition to or instead of the water treatment agent used in normal times. As for another water treatment agent, if the slime control agent normally used is an oxidizing agent, the slime control effect may be improved by using an organic slime control agent, which has a different principle of action from oxidizing agents, rather than increasing the amount. In addition, while commonly used scale inhibitors have a strong effect on depositing scale, they are weak at dissolving the scale once it has been deposited, and a large amount of scale inhibitor is required to dissolve the scale. Therefore, the effect of inhibiting deposition can be increased by adding a scale inhibitor with a different effect on inhibiting deposition. Furthermore, after the adding step (step S6) of adding the water treatment agent, the cooling tower efficiency is continuously calculated for each cell 51 by a calculation step (step S1) based on the measured values ​​in the first and second measurement steps. Next, similar processing is performed to determine whether the average value of the calculated cooling tower efficiency is higher than a predetermined set value (step S5). If it is determined that the average value of the cooling tower efficiency is higher than the predetermined set value (step S5 YES), the cooling tower state evaluation method can be terminated (END). As a result, when it is found that the cooling tower efficiency of the cooling tower 5 has decreased and the performance of the cooling tower 5 has deteriorated, a water treatment agent can be injected into the cooling water, etc., to quickly restore operation, and then, by understanding the condition of the cooling tower 5 and evaluating the performance of each cell 51 individually, the performance of the cooling tower 5 can be stabilized and energy-saving operation can be continuously carried out.

[0032] Alternatively, the cooling tower condition evaluation method can be ended (END) directly after the addition step (step S6) of adding the water treatment agent. This makes it possible to predict the cooling tower efficiency that will be restored depending on the type and amount of water treatment agent added. Also, time is required for the added water treatment agent to affect the cooling tower efficiency. Therefore, the cooling tower condition evaluation method can be ended after the addition step (step S6) and then started again as necessary after a certain amount of time has passed.

[0033] In the addition process (step S6) for adding a water treatment agent, if there is one type of water treatment agent, the amount of water treatment agent added can be increased to a second stage when the cooling tower efficiency is 90% or less, making it 1.5 times the normal amount, or the amount of water treatment agent added can be increased to a third stage when the cooling tower efficiency is 80% or less, making it 2.0 times the normal amount. Note that in the addition process (step S6), the stage in which the water treatment agent is added in response to a decrease due to evaporation or scattering of cooling water, regardless of the cooling tower efficiency, is considered to be the first stage. In addition, when there are two types of water treatment agents, for example, one water treatment agent that is normally added and another water treatment agent are added. When the cooling tower efficiency is 90% or less, 1 m of cooling water is added each time. 3 Add 200g of another water treatment agent per 24 hours. After the cooling tower efficiency is restored by repeating the addition of another water treatment agent every 24 hours, add 1m of cooling water per 24 hours. If the cooling tower efficiency is 80% or less, add 1m of cooling water per 24 hours. 3 Add 400g of another water treatment agent per 12 hours. After the cooling tower efficiency is restored by repeating the addition of another water treatment agent every 12 hours, the addition of the water treatment agent is stopped. In addition, if the cooling tower efficiency is 90% or less, an additional 0.5 times the amount of another water treatment agent that would normally be added is added, and if the cooling tower efficiency is 80% or less, an additional 1.0 times the amount of another water treatment agent that would normally be added is added. As a result, when the cooling tower efficiency decreases and the performance of the cooling tower deteriorates, the cooling tower efficiency can be quickly restored by quickly adding a water treatment agent appropriate to the state in which the cooling tower efficiency has decreased.

[0034] Moreover, the cooling tower state evaluation method of the present invention can calculate the cooling tower efficiency for each cell. Fig. 5 is a diagram showing a flowchart explaining the cooling tower state evaluation method of the present invention. The cooling tower condition evaluation method of the present invention further includes a cell calculation step of calculating the cooling tower efficiency of each cell 51 of the cooling tower 5 based on the prerecorded cooling tower efficiency of the cell 51 and the calculated cooling tower efficiency of the cooling tower 5. In a cooling tower 5 having a plurality of cells 51, an operation method is often adopted in which the operating cells 51 are switched in sequence so as to average the operation time of each fan 52. Therefore, as the cooling tower 5 operates, the cooling tower efficiency is continuously calculated, and at the same time, the operating cells 51 are monitored from the current value operating the fans 52, so that the cooling tower efficiency of each cell 51 can also be calculated in the cell evaluation step. Furthermore, a recording step is provided for recording the calculated cooling tower efficiency of each cell 51. Note that, here, a cooling tower 5 having one inoperable cell 51 will be described.

[0035] First, the control device 4 identifies the cell 51 whose cooling tower efficiency was recorded the oldest among the recorded cooling tower efficiencies of each cell 51 (step S11). Here, the identified cell 51 is referred to as cell A. Next, the cooling tower efficiency of cell A is calculated from the calculated cooling tower efficiency and the cooling tower efficiencies of each cell 51 other than cell A, and the value of the cooling tower efficiency recorded in the control device 4 is updated (step S12). This is because the cooling tower efficiency of each cell 51 has already been calculated among the cooling towers 5 that are in operation. Also, even at the beginning, the cooling tower efficiency of each cell 51 has been calculated when the cooling tower 5 is first operated. Therefore, the cooling tower efficiency that is the contribution of cell A can be calculated from the calculated cooling tower efficiency of the cooling tower 5 and the cooling tower efficiency of the operating cell 51.

[0036] Next, the cooling tower efficiency of each cell 51 is calculated continuously by repeating the calculation of the cooling tower efficiency of the cell 51 every time the operation order of each cell 51 of the cooling tower 5 is changed (step S13). Furthermore, after each cell 51 is evaluated, it is recorded in the control device 4 by a recording process. Therefore, the cooling tower efficiency of each cell 51 provided in the cooling tower 5 can be continuously grasped. This makes it possible to accurately grasp the current performance state of each cell 51. Furthermore, when performance deteriorates, the deteriorated efficiency can be quickly restored by supplying a water treatment agent.

[0037] FIG. 6 is a flowchart illustrating the cooling tower state evaluation method of the present invention. Each time the operation order of each cell 51 of the cooling tower 5 is switched, the calculation of the cooling tower efficiency of the cell 51 is repeated, thereby moving to continuously calculate the cooling tower efficiency of each cell 51 (step S13). Furthermore, the cooling tower state evaluation method of the present invention determines whether the calculated cooling tower efficiency of each cell 51 is higher than a predetermined set value (step S14). In step S14, when it is determined that the calculated cooling tower efficiency for each cell 51 is higher than a predetermined set value (step S14 YES), the addition of water treatment agent is not actively carried out, but the water treatment agent may be added so that the concentration of the water treatment agent decreases due to evaporation and scattering of the cooling water to reach the normal set concentration. After the water treatment agent is added, the cooling tower state evaluation method can be ended (END).

[0038] On the other hand, when it is determined that the cooling tower efficiency of the cell 51 is lower than the set value (step S14 NO), the water treatment agent is added in an amount greater than usual so that the water treatment agent reaches the normal set concentration in order to recover the cooling tower efficiency (step S15). This is a mechanism that allows the deterioration of the cooling tower efficiency to be quickly restored. By determining whether the cooling tower efficiency of each cell 51 is higher than a predetermined set value, it is possible to determine whether a sudden decrease in the cooling tower efficiency of a cell 51 is a malfunction or other problem, regardless of whether a water treatment agent is being supplied, and whether a continuous decrease in the cooling tower efficiency of a cell 51 is due to deterioration over time. It is also possible to determine the timing of repairs and renovations of the cells 51. Furthermore, while repairs and renovations of cooling towers 51 are often carried out on a cell-by-cell basis to reduce costs, by understanding the cooling tower efficiency of each cell 51, it is possible to prioritize repairs and renovations of cells 51 with significant capacity declines, thereby maximizing cost-effectiveness. Also, after the water treatment agent is added, the cooling tower condition evaluation method can be ended (END). However, here, again, after the addition step (step S15), the process moves to identifying the cell 51 in which the cooling tower efficiency was recorded the oldest (step S11). Next, similar processing is performed to determine whether the calculated cooling tower efficiency for each cell is higher than a predetermined set value (step S14). If the average value of the cooling tower efficiency is higher than the predetermined set value, the cooling tower efficiency is high, and the cooling tower condition evaluation method can be ended (END). As a result, when it is found that the cooling tower efficiency of the cooling tower 5 has decreased and the performance of the cooling tower 5 has deteriorated, a water treatment agent can be injected into the cooling water, etc., to quickly restore the cooling tower 5. After that, by understanding the condition of the cooling tower 5 and evaluating the performance of each cell individually, the performance of the cooling tower 5 can be stabilized and energy-saving operation can be continuously performed.

[0039] Alternatively, the cooling tower 5 condition evaluation method can be ended (END) directly after the addition step (step S14) of adding the water treatment agent. This makes it possible to predict the cooling tower efficiency that will be restored depending on the type and amount of water treatment agent added. Also, time is required for the added water treatment agent to affect the cooling tower efficiency. Therefore, the cooling tower condition evaluation method can be ended after the addition step (step S14), and can be started again as necessary after a certain amount of time has passed.

[0040] 7 is a diagram showing the configuration of one embodiment of a system for implementing the cooling tower state evaluation method of the present invention. A cooling tower system 100 for implementing the cooling tower state evaluation method is connected to a heat source such as a boiler, which is a thermal load of an object to be cooled, although not shown. The cooling tower system 100 further includes an input device 1, a communication means 2, a control device 4, a cooling tower 5 as a cooling facility 3, a circulation pump 55, and a heat exchanger 6, and also a feedwater pump (not shown). In addition, the cooling tower system 100 can be connected to the Internet 23 by placing the communication means 2 on the web.

[0041] The input device 1 has an input section 11 through which an operator 8 inputs operating conditions for operating the cooling equipment 3. The input device 1 has a display section 12 that displays the operating conditions input by the operator 8 and the operating status of the cooling equipment 3 and the like. The input device 1 may be directly connected to the control device 4 through a LAN line 21 without going through the Internet 23. The input device 1 may also be connected to an external data server 14 through a LAN line, a telephone line, or the like to obtain necessary weather forecast information. The input device 1 may also be connected to the control device 4 by being connected to the Internet 23 through a LAN line 22. Similarly, the Internet 23 is connected to a number of intermediate servers, and can be connected to, for example, a weather forecast server that handles weather forecast information, a calculation processing server that performs calculation processing, an intermediate server that processes automatic control, and the like (not shown). Therefore, data on the outside temperature, relative humidity, and atmospheric pressure can be obtained from the Internet 23 for a cooling tower 5 located in a remote location and used in a cooling tower state evaluation method. Furthermore, the cooling tower efficiency of the cooling tower 5 can be evaluated from a remote location to operate the cooling tower 5.

[0042] The control device 4 receives instructions for operation conditions from the input device 1, and performs calculations according to the received contents to calculate operation conditions for the cooling equipment 3. The control device 4 includes a receiving unit 42 that performs the calculations, and a control unit 41 that transmits the operation conditions to the fan 52 and the circulating pump 55 of the cooling equipment 3. The control unit 41 in the control device 4 constitutes part of the cooling tower system 100 as a distributed control system (DCS). The control device 4 equipped with the distributed control system (DCS) is also connected to the input device 1 via the Internet 2, and efficient control can be implemented by mutual communication.

[0043] In the operation control method of the cooling tower system 100, an operator 8 inputs the operating conditions into the input device 1 and operates the cooling equipment 3 via the control device 4. At this time, it is possible to find operating conditions that minimize the total power consumption of the fan 52 and the circulation pump 55 in the cooling equipment 3, using the cooling tower efficiency of the cooling tower 5 in the cooling equipment 3 as a condition.

[0044] FIG. 8 is a diagram showing the configuration of one embodiment of a system for implementing the cooling tower state evaluation method of the present invention. The cooling tower system 100 for carrying out the cooling tower condition evaluation method further includes a water treatment agent addition device 7. In Fig. 8, the water treatment agent is added to a pipe 53 connecting the cooling tower 5 and the heat exchanger 6. The water treatment agent can also be added directly to the cooling water of the cooling tower 5. Furthermore, the water treatment agent adding device 7 is connected to the control device 4. The control device 4 determines to add a water treatment agent in the control unit 41 using the measured value by the measuring means received in the receiving unit 42. When the control device 4 determines to add a water treatment agent to the cooling tower 5, the control device 4 transmits an instruction to the water treatment agent adding device 7 to add the water treatment agent to the pipe 53 of the cooling tower 5 or the like by a transport pump or the like (not shown). In this way, by knowing the cooling tower efficiency of each cell 51 in the cooling tower 5, it is possible to repair or renovate a cell 51 whose capacity has significantly decreased. EXAMPLES

[0045] The embodiments and effects of the present invention will be described in detail below with reference to specific examples. The examples described here are merely examples of the embodiments of the present invention, and are not intended to limit the scope and effects of the present invention.

[0046] In the example, the cooling tower efficiency of a cooling facility installed in a chemical plant was calculated under the following three conditions. The cooling equipment is equipped with a cooling tower with N cells, a circulating pump, a heat exchanger, and a control device equipped with a measuring means for measuring the circulating cooling water, outside temperature, humidity, and atmospheric pressure, and a collection panel for collecting data.The cooling tower is also equipped with a fan, a water distribution pipe, a measuring means for measuring the frequency of the current that operates the fan, and a measuring means for measuring the temperature of the cooling water supplied to the cooling tower and the temperature of the cooling water discharged from the cooling tower.

[0047] The experimental conditions were the following three conditions (1), (2), and (3). (1) Conventional example: The cooling tower efficiency is calculated assuming that all cells are operating at all times, without taking into account whether the fans in each cell are operating or not. (2) Comparative example: The cooling tower efficiency is calculated taking into account whether the fan of each cell is operating or not, but assuming that the drop in water temperature in cells where the fan is not operating is zero, and furthermore, not including such cells in the number of cells used in the calculation. (3) Example: Taking into account the ventilation volume calculated based on whether the fan of each cell is operating or not and the actual water temperature of the cell where the fan is not operating, the contribution of this is corrected to calculate the cooling tower efficiency.

[0048] The operating conditions of the cooling equipment are as follows: Measurement period: February 1st to 28th (outdoor wet bulb temperature -2.6 to 13.8°C) Operating conditions: The number of fans operating is adjusted according to the cooling water temperature.

[0049] The results of the above conditions are shown in Figure 9. Figure 9 shows the cooling tower efficiency under experimental conditions (1), (2), and (3) from February 1 to 28, and the period when there was a change in the number of cells in operation in the cooling tower. In Figure 9, the shaded areas represent the periods when the specified number of cooling towers were in operation, and the unshaded areas represent the periods when one cell less than the specified number was in operation.

[0050] As shown in FIG. 9, under experimental conditions (1) and (2), the cooling tower efficiency value fluctuates greatly due to fluctuations in the number of operating cells. On the other hand, under experimental condition (3), the cooling tower efficiency remained almost constant throughout the measurement period, regardless of fluctuations in the number of operating cells. Cooling towers are used for long periods of time, from a dozen years to several decades, and if appropriate cooling water treatment and maintenance are performed, the decline in cooling tower efficiency is often limited to about 20-50%, even for cooling towers that have been installed for more than a dozen years. Therefore, even for cooling towers that have been installed for more than a dozen years, the change in cooling tower efficiency over a short period of time, such as one month, is thought to be very small. During the period in which data was collected for this experiment, there were no events that significantly changed the cooling tower efficiency (such as the collapse of equipment or the sudden occurrence or resolution of scale or slime). These results show that the cooling tower efficiency calculated under the experimental condition (3), which remained almost constant throughout the measurement period, more accurately calculates the cooling tower efficiency of the cooling tower including the cell compared to the other experimental conditions (1) and (2).

[0051] Next, the cooling tower efficiency was calculated under the following experimental condition (4). Although the cooling equipment was different from those used in experimental conditions (1) to (3), in experimental condition (4), the cooling tower efficiency was calculated according to the operating conditions of the cooling equipment similar to those used in experimental conditions (1) to (3), and the water treatment agent was added based on this cooling tower efficiency. Measurement period: Early April to early August (outdoor wet bulb temperature 20.4 to 32.8°C) Operating Conditions: Based on the calculated cooling tower efficiency, a predetermined amount of water treatment agent was added, as described below.

[0052] Water treatment agent for preventing adhesion of dirt to cooling water system is applied at 200g / m 3 Amount of cooling water added: 62m 3 For single-cell cooling towers with a cooling capacity of 1000 g / m2 / h, the cooling tower efficiency is measured at the beginning of the month, and if the cooling tower efficiency is over 90%, the cooling tower efficiency is set at 200 g / m2 as usual. 3 If the concentration is below 90%, the water treatment agent concentration is increased to 300 g / m, which is 1.5 times the normal concentration. 3 It was added so that Here, the predetermined setting value for adding water treatment agent is a cooling tower efficiency of 90%. If the cooling tower efficiency is determined to be lower than 90%, the type of water treatment agent and the amount to be added are set. Here, it was decided to add 1.5 times the amount of the same water treatment agent as the water treatment agent intended to prevent the adhesion of dirt to the cooling water system. This allows the water treatment agent concentration to be increased to 300 g / m 3 The cooling tower efficiency was restored by increasing the cooling tower temperature to 85-92% and the cooling tower was operated stably between early April and early August. The progress of the cooling tower efficiency is shown in Table 1. As shown in Table 1, it was found that stable cooling tower efficiency could be obtained under the experimental condition (4) even if evaporation and scattering of cooling water occurred.

[0053] [Table 1]

[0054] The cooling tower efficiency of the cooling equipment can be accurately calculated by the cooling tower condition evaluation method of the present invention. It was also found that the cooling tower system of the present invention enables early recovery from the performance deterioration of the cooling tower and stable operation of the cooling tower. [Explanation of symbols]

[0055] 1 Input Device 11 Input section 12 Display section 2. Means of communication 21, 22 Connection lines 23 Internet 3 Cooling equipment 4. Control device 41 Control section 42 Receiving section 421 Inlet temperature measurement means (T1) 422 Outlet temperature measuring means (T2) 423 Cell outlet temperature measuring means (T3) 424 Environmental measurement means 5 cooling tower 51(511, ..., 51n) cells 52(521, ..., 52n) Fan 53(531,…,53n) Pipeline 54 (541, ..., 54n) Electrical measuring means 55 Circulation Pump 6 Heat exchanger 7 Water treatment agent addition device 8. Operator 100 Cooling Tower System

Claims

1. A plurality of cells each having a fan that reduces the temperature of the cooling water by evaporating a portion of the cooling water by blowing air; a cooling tower including a pipeline connected to the plurality of cells or a single cell and configured to externally circulate the cooling water, the pipeline being configured such that the cooling water is supplied from an inlet of the pipeline and is discharged from an outlet of the pipeline; a heat exchanger disposed at a position midway along the path of the cooling water from the outlet to the inlet of the pipeline of the cell, for heating the cooling water; In the cooling tower condition evaluation method for calculating the cooling tower efficiency of the cooling tower, a first measuring step of measuring an outlet temperature of the cooling water from the outlet of the pipe before passing through the heat exchanger, an inlet temperature of the cooling water between after passing through the heat exchanger and the inlet of the pipe, and a current value, power, or frequency of a fan of each of the plurality of cells; A second measurement step of measuring an outside air temperature, a relative humidity, and an atmospheric pressure in an installation environment of the cooling tower; A calculation step of continuously calculating the cooling tower efficiency for each of the cells based on the measured values ​​in the first and second measurement steps; A cooling tower condition assessment method, comprising:

2. The cooling tower condition evaluation method includes: a correction step of calculating an amount of ventilation generated by natural convection in the cell where the operation of the fan is stopped or by the operation of the fan of the adjacent cell from a temperature of the cooling water at an inlet of the cooling tower and a cooling water temperature of any one of the cells, and correcting the cooling tower efficiency; The cooling tower condition evaluation method according to claim 1 .

3. 3. The cooling tower condition evaluation method according to claim 2, further comprising a cell calculation step of calculating a cooling tower efficiency of each cell of the cooling tower based on a previously recorded cooling tower efficiency of the cell and a calculated cooling tower efficiency of the cooling tower.

4. The cooling tower condition evaluation method includes: A recording step of calculating and recording the cooling tower efficiency of each cell every time the cell is switched over; The cooling tower condition evaluation method according to claim 3.

5. A plurality of cells each having a fan that reduces the temperature of the cooling water by evaporating a portion of the cooling water by blowing air; a cooling tower including a pipeline connected to the plurality of cells or a single cell and configured to externally circulate the cooling water, the pipeline being configured such that the cooling water is supplied from an inlet of the pipeline and is discharged from an outlet of the pipeline; A method for evaluating a state of a cooling tower, comprising: a heat exchanger disposed at a position midway along the path of the cooling water from an outlet to an inlet of the pipeline of the cell, the heat exchanger heating the cooling water, the method comprising: The cooling tower condition evaluation method includes: a first measuring step of measuring an outlet temperature of the cooling water from the outlet of the pipe before passing through the heat exchanger, an inlet temperature of the cooling water between after passing through the heat exchanger and the inlet of the pipe, and a current value, power, or frequency of a fan of each of the plurality of cells; A second measurement step of measuring an outside air temperature, a relative humidity, and an atmospheric pressure in an installation environment of the cooling tower; A calculation step of continuously calculating the cooling tower efficiency for each of the cells based on the measured values ​​in the first and second measurement steps; an addition step of adding a water treatment agent to the cooling water based on the cooling tower efficiency calculated in the calculation step.

6. The cooling tower condition evaluation method includes:

6. The cooling tower state evaluation method according to claim 5, wherein after the adding step, the cooling tower efficiency is continuously calculated for each cell in the calculating step based on the measured values ​​in the first and second measuring steps.

7. The cooling tower condition evaluation method includes: a correction step of calculating an amount of ventilation generated by natural convection in the cell where the operation of the fan has been stopped or by operation of the fan in the adjacent cell from a temperature of the cooling water at an inlet of the cooling tower and a cooling water temperature in any one of the cells, and correcting the cooling tower efficiency; The cooling tower condition evaluation method according to claim 6 , wherein the adding step adds the water treatment agent to the cooling water based on the cooling tower efficiency corrected in the correcting step.

8. The cooling tower condition evaluation method includes: A cell calculation step of calculating a cooling tower efficiency of each cell of the cooling tower based on a previously recorded cooling tower efficiency of the cell and a calculated cooling tower efficiency of the cooling tower, The cooling tower state evaluation method according to claim 6 , wherein the adding step adds the water treatment agent to the cooling water based on the cooling tower efficiency calculated in the cell calculation step.

9. The cooling tower condition evaluation method includes: The adding step adds the water treatment agent when the cooling tower efficiency is lower than a predetermined set value. The cooling tower condition evaluation method according to claim 7 or 8.

10. The cooling tower condition evaluation method includes: The adding step adds a predetermined amount of the water treatment agent depending on a difference between the cooling tower efficiency and a predetermined set value. The cooling tower condition evaluation method according to claim 7 or 8.

11. A plurality of cells each having a fan that reduces the temperature of the cooling water by evaporating a portion of the cooling water by blowing air; a cooling tower including a pipeline connected to the plurality of cells or a single cell and configured to externally circulate the cooling water, the pipeline being configured such that the cooling water is supplied from an inlet of the pipeline and is discharged from an outlet of the pipeline; A heat exchanger is provided at a position midway along the path of the cooling water from the outlet to the inlet of the pipeline of the cell, and cools the cooling water. A cooling tower system for calculating a cooling tower efficiency of the cooling tower, a first measuring means for measuring an outlet temperature of the cooling water from the outlet of the pipe before passing through the heat exchanger, an inlet temperature of the cooling water from after passing through the heat exchanger to the inlet of the pipe, and a current value, power, or frequency of a fan of each of the plurality of cells; A second measuring means for measuring an outside air temperature, a relative humidity, and an atmospheric pressure in an installation environment of the cooling tower; and a calculation means for continuously calculating the cooling tower efficiency for each of the cells based on the measured values ​​in the first and second measurement means.

12. 12. The cooling tower system according to claim 11, wherein the calculation means calculates the amount of ventilation generated by natural convection in the cell where the operation of the fan has been stopped or by operation of the fan of an adjacent cell from the temperature of the cooling water at the inlet of the cooling tower and the cooling water temperature of any one of the cells, and corrects the cooling tower efficiency.

13. 13. The cooling tower system according to claim 12, wherein the calculation means includes a cell calculation step of calculating the cooling tower efficiency of each cell of the cooling tower based on a previously recorded cooling tower efficiency of the cell and the calculated cooling tower efficiency of the cooling tower.

14. 14. The cooling tower system of claim 13, wherein the calculation means calculates and records the cooling tower efficiency of each cell each time the cell switches operation.

15. The cooling tower system comprises: The calculation means is connected to the first measurement means and the second measurement means via a communication means.

12. The cooling tower system of claim 11.

16. A plurality of cells each having a fan that reduces the temperature of the cooling water by evaporating a portion of the cooling water by blowing air; a cooling tower including a pipeline connected to the plurality of cells or a single cell and configured to externally circulate the cooling water, the pipeline being configured such that the cooling water is supplied from an inlet of the pipeline and is discharged from an outlet of the pipeline; A heat exchanger disposed at a position midway between the outlet and the inlet of the pipe of the cell, for cooling the cooling water, comprising: The cooling system comprises: a first measuring means for measuring an outlet temperature of the cooling water from the outlet of the pipe before passing through the heat exchanger, an inlet temperature of the cooling water from after passing through the heat exchanger to the inlet of the pipe, and a current value, power, or frequency of a fan of each of the plurality of cells; A second measuring means for measuring an outside air temperature, a relative humidity, and an atmospheric pressure in an installation environment of the cooling tower; A calculation means for continuously calculating the cooling tower efficiency for each of the cells based on the measured values ​​in the first and second measurement means; A water treatment agent adding means for adding the water treatment agent to the cooling water based on the cooling tower efficiency calculated by the calculation means; and a control means for controlling the amount of the water treatment agent added.

17. The cooling tower system comprises:

17. The cooling tower system according to claim 16, wherein after the adding step, the cooling tower efficiency is continuously calculated for each of the cells by the calculating step based on the measured values ​​in the first and second measuring steps.

18. The control means a cooling tower efficiency correcting unit that calculates a ventilation amount generated by natural convection in the cell where the operation of the fan has been stopped or by the operation of the fan in the adjacent cell from a cooling water temperature at an inlet of the cooling tower and a cooling water temperature in any one of the cells, and controls the calculation unit that corrects the cooling tower efficiency.

20. The cooling tower system of claim 17.

19. The control means 18. The cooling tower system according to claim 17, further comprising a cell calculation step of calculating the cooling tower efficiency of each cell of the cooling tower based on a previously recorded cooling tower efficiency of the cell and a calculated cooling tower efficiency of the cooling tower.

20. The control means controls the addition step of adding the water treatment agent when the cooling tower efficiency is lower than a predetermined set value.

20. A cooling tower system according to claim 18 or 19.

21. 20. The cooling tower system according to claim 18 or 19, wherein the control means controls the addition step of adding a predetermined amount of the water treatment agent based on a difference between the cooling tower efficiency and a predetermined set value.

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