Cooling tower condition assessment method 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 assessment method and a cooling tower system. [Background technology]

[0002] Power plants, chemical plants, air conditioning plants, and other facilities operate while generating or recovering large amounts of heat. To control this heat and operate the plants stably, cooling tower systems are used to repeatedly use cooling water, which is made up of various fluids such as water. It is known that the performance of cooling towers in cooling tower systems deteriorates over time, and in order to operate the plants stably, it is desirable to constantly monitor the extent of this deterioration. Conventionally, cooling towers are installed with multiple cells, each with its own fan, connected together so that each cell can operate independently, with the number of fans controlled according to the outside air conditions and operating load. Although each cell is installed adjacent to another, the degree of performance degradation varies depending on factors such as the amount of sunlight, the surrounding environment, and the layout of water supply piping. Therefore, it is desirable to understand the degree of performance degradation for each cell. However, until now, evaluations of the performance degradation state of a cooling tower system have often been performed by evaluating the entire cooling tower, with its connected cells, without incorporating evaluations of individual cells.

[0003] In addition, 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 circulating water will be hindered. Also, if the upper sprinkler tank becomes clogged, the water will be sprayed unevenly, causing the balance between water volume and 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 tubes become dirty, the heat exchange efficiency between the spray water and the circulating water decreases. When the cooling tower becomes dirty in this way, the cooling tower fan needs to operate for a longer time to maintain the same water temperature as before the dirt became present, resulting in energy loss. Furthermore, even if the fan operates continuously, the desired water temperature may not be achieved, and the supply water temperature may rise. The rise in supply water temperature causes the problem of increased chiller power consumption. On the other hand, measures to prevent fouling of cooling towers include automatic blowdown 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 the water input to the wet cooling tower, the temperature of the 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 determining whether the fan is on or off, it cannot accurately evaluate the cooling tower performance of a cooling tower whose fan operating status 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 when the fan is stopped, and that there is no change in the temperature of the cooling water. However, actual operating data from cooling towers has shown that drafts occur even in cells where the fan is stopped, and the temperature of the cooling water drops.

[0005] Based on 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 it is also desirable to make the evaluation after correcting for the ventilation within the cells where the fans are stopped. Furthermore, if a further deterioration in the performance of the cooling tower is discovered, it is desirable to quickly restore it by injecting water treatment agents into the cooling water, and then to carry out 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] Japanese Patent Application Publication No. 2019-100662 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 multiple cells and operates by turning on and off fans that blow air within each cell, by continuously evaluating the condition of each cell. Furthermore, it is an object of the present invention to provide a cooling system that applies a cooling tower condition assessment 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 pipe connected to the plurality of cells or a single cell and configured to circulate the cooling water externally, the pipe being configured so that the cooling water is supplied from an inlet of the pipe and discharged from an outlet of the pipe; and a heat exchanger disposed midway along the path from the outlet to the inlet of the pipe of the cell for heating the cooling water, wherein the cooling tower efficiency of the cooling tower is calculated. A condition evaluation method for a cooling tower, comprising: a first measurement step of measuring the outlet temperature of the cooling water from the outlet of the pipe before passing through the heat exchanger, the inlet temperature of the cooling water from after passing through the heat exchanger to the inlet of the pipe, and the 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 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) includes a correction step of calculating the amount of ventilation generated by natural convection in the cell where the fan operation has been stopped or by the operation of the fan in the adjacent cell from the temperature of the cooling water at the inlet of the cooling tower and the temperature of the cooling water in 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 pre-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) Multiple cells each having a fan that reduces the temperature of the cooling water by evaporating a portion of the cooling water with air; a cooling tower including a pipeline connected to the plurality of cells or a single cell and configured to allow the cooling water to be externally circulated, the pipeline configured so that the cooling water is supplied from an inlet of the pipeline and 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 pipe of the cell, for heating the cooling water, 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 duct before passing through the heat exchanger, an inlet temperature of the cooling water from passing through the heat exchanger to the inlet of the duct, 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: (5) A 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 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 operation of the fan has been stopped or by operation of the fan in the adjacent cell from the temperature of the cooling water at the inlet of the cooling tower and the temperature of the cooling water in any one of the cells, and correcting the cooling tower efficiency; (6) 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: a cell calculation step of calculating the cooling tower efficiency of each cell of the cooling tower based on the pre-recorded cooling tower efficiency of the cell and the 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 cooling tower state evaluation method 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 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 that lowers the temperature of the cooling water by evaporating part of the cooling water with air; a pipe connected to the plurality of cells or a single cell and configured to circulate the cooling water externally, the pipe being configured so that the cooling water is supplied from an inlet of the pipe and discharged from an outlet of the pipe; and a heat exchanger disposed midway along the cooling water's path from the outlet to the inlet of the pipe of the cell and heating the cooling water, the cooling tower system calculating the cooling tower efficiency of the cooling tower, the cooling tower system comprising: a first measuring means that measures the outlet temperature of the cooling water from the outlet of the pipe before passing through the heat exchanger, the inlet temperature of the cooling water from after passing through the heat exchanger to the inlet of the pipe, the current value, power, or frequency of the fans of each of the plurality of cells; a second measuring means that measures the outside air temperature, relative humidity, and atmospheric pressure in the installation environment of the cooling tower; and a calculating means that continuously calculates the cooling tower efficiency for each of the cells based on the measured values ​​of the first and second measuring means. (12) A cooling tower system as described in (11), wherein the calculation means calculates the amount of ventilation generated by natural convection in the cell where the fan has stopped operating or by the operation of the fan in the 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 the pre-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 the first measurement means and the second measurement means via a communication means.

[0011] (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 allow the cooling water to be externally circulated, the pipeline configured so that the cooling water is supplied from an inlet of the pipeline and 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 cooling 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 duct 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 duct, 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 ​​of 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 calculating 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 system continuously calculates the cooling tower efficiency for each cell by the calculating step based on the measured values ​​in the first and second measuring steps. (18) The cooling tower system described in (16), wherein the control means calculates the amount of ventilation generated by natural convection in the cell where the fan operation has been stopped or by the operation of the fan in the adjacent cell from the temperature of the cooling water at the inlet of the cooling tower and the temperature of the cooling water in any one of the cells, and controls the calculation means that corrects the cooling tower efficiency. (19) The cooling tower system described in (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 the pre-recorded cooling tower efficiency of the cell and the 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 aforementioned 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 the difference between the cooling tower efficiency and a predetermined set value. [Effects of the Invention]

[0012] According to the present invention, a cooling tower condition evaluation method is provided for a cooling tower that is composed of multiple cells, each having a fan that operates intermittently to blow air within the cell, and that accurately calculates the cooling tower efficiency of the cooling tower by evaluating the condition of each cell, and a cooling tower system that uses this method can be provided. Furthermore, 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 this method can be provided. [Brief explanation 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. [Figure 2] FIG. 1 is a diagram showing an embodiment of a cooling tower condition evaluation method of the present invention. [Figure 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. [Figure 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 illustrating 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 illustrating 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 when changes occurred in the number of operating fans. DETAILED DESCRIPTION OF THE INVENTION

[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 part of the cooling water by blowing air; a pipe connected to a plurality of or a single cell and configured to allow the cooling water to circulate externally, the pipe being configured so that the cooling water is supplied from an inlet of the pipe and discharged from an outlet of the pipe; and a heat exchanger arranged midway along the cooling water's path from the outlet to the inlet of the cell's pipe and heating the cooling water. The method calculates the cooling tower efficiency of the cooling tower, and includes a first measurement step of measuring the outlet temperature of the cooling water from the outlet of the pipe before passing through the heat exchanger, the inlet temperature of the cooling water from after passing through the heat exchanger to the inlet of the pipe, and the current value, power, or frequency of the fan 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 an embodiment of the cooling tower condition evaluation method of the present invention. The cooling equipment 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). Each cell 51 includes fans 521, 522, 523, ..., 52n. Each cell 51 includes a filler that increases the contact efficiency between the cooling water and the air, and a water tank that directly contacts the cooling water. The cooling tower 5 includes electricity measuring means 541, ..., 54n that measure the current, power, or frequency of the electricity sent to the fan 52. The cooling tower 53 circulates the cooling water, and the cooling tower circulates the cooling water. The cooling tower circulates the cooling water. The cooling tower circulates the cooling water. The cooling tower circulates the cooling water. The cooling tower circulates the cooling water. The cooling tower circulates the cooling water. The cooling water ... Furthermore, a second measuring means is provided, which includes an environment measuring means 424 for measuring the outside temperature, relative humidity, and atmospheric pressure in the installation environment of the cooling tower 5.

[0017] The control device 4 includes a control unit 41 that controls the amount of electricity sent to the fan 52 and the amount of water flowing from the circulation pump 55. The control unit 41 also has functions such as recording, as data via the receiving unit 42, measurements taken by a first measuring unit including an electricity measuring unit 54, an inlet temperature measuring unit (T1) 421, an outlet temperature measuring unit (T2) 422, and a cell outlet temperature measuring unit (T3) 423, and a second measuring unit including an environmental measuring unit 424 for measuring the outside air temperature, relative humidity, atmospheric pressure, etc., where the cooling tower 5 is installed. The control unit 41 also uses the measurements received by the receiving unit 42 to calculate the cooling efficiency of the cooling tower 5 using a calculation unit, thereby implementing a condition evaluation method for evaluating the cooling tower condition. The control device 4 is also connected to other devices and systems, such as input devices and communication units such as the Internet, although not shown.

[0018] Conventional cooling tower condition evaluation methods do not address the issue of how to monitor the fan 52's start / stop status. This makes it difficult to accurately evaluate the cooling tower efficiency of cooling towers 5, whose fan 52 operation status constantly changes. Even if the fan 52's start / stop status is taken into account, it is assumed that there is zero draft within a cell 51 where the fan 52 is stopped, and that there is no change in the cooling water temperature. However, even within a cell 51 where the fan 52 is stopped, drafts occur due to ambient air convection and the operation of fans 52 in adjacent cells 51, causing the cooling water temperature to drop. It has been found that calculating cooling tower efficiency while ignoring this drop in water temperature, especially in winter when the wet-bulb temperature drops, results in an overestimate. Furthermore, because the degree of performance degradation often varies between cells 51 depending on the cooling tower's installation environment, 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 an embodiment of the cooling tower condition evaluation method of the present invention. The cooling tower condition evaluation method of the present invention includes a water treatment agent addition means that performs an addition step of adding a water treatment agent to cooling water. As shown in FIG. 2, the water treatment agent addition means includes a water treatment agent addition device 7. Although not shown, the water treatment agent addition device 7 includes a water treatment agent tank that stores the water treatment agent and a transfer pump that transports 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 can add the water treatment agent at any point in the storage tank, circulation path, or make-up water path. When the water treatment agent to be added is a solid, there is no particular restriction on the method of adding it to the cooling tower 5 and the pipeline 53, but it is preferable to immerse the water treatment agent in the cooling water or to bring part of the water treatment agent into contact with the cooling water. When the water treatment agent is a liquid, it is preferable to add it by using a tube pump, a bellows pump, or by letting it fall by gravity without using a transport pump.

[0021] Examples of water treatment agents include slime control agents and scale inhibitors. The components of the water treatment agent are not particularly important, but oxidizing agents are preferred, and chlorine agents are particularly desirable. Furthermore, free chlorine agents are highly corrosive and may damage the cooling tower 5, so it is more desirable for the agent to contain bound 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 interval between doses is based on the period during which the bactericidal effect is maintained, and varies 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 their adhesion and proliferation inside pipes. Furthermore, scale inhibitors are water treatment agents that remove water-insoluble oxides that have accumulated in water supply and drainage facilities, equipment, and piping. Once they crystallize and solidify inside piping equipment, they are extremely 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 specific examples include polymers with 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 shown in FIG. 2, the control means is provided in the control unit 41 of the control device 4. The control unit 41 of the control device 4 is composed of, for example, a microcomputer and electronic circuits, which include a calculation means such as a CPU that executes a program and a storage means such as a ROM that stores the program and calculation results. Using the measured values ​​received by the receiving unit 42, the calculation means included in the control unit 41 executes the condition evaluation method for evaluating the condition of the cooling tower 5. Furthermore, the control device 4 has a function for 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 pipeline 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 the cooling water is 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 cooling water is not uniform, and furthermore, cooling tower efficiency decreases with use over time due to deterioration of the cooling tower 5, clogging of the cells 51 due to fouling, 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 fluctuations in cooling water but also deterioration and fouling of the cooling tower 5.

[0025] FIG. 3 is a flowchart illustrating the cooling tower condition evaluation method of the present invention. First, the cooling tower efficiency of the cells 51 that make up 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 that includes a control unit 41 that has 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 more 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 within the inactive cell is calculated from the temperature difference (T1-T3) within the cell where the fan 52 is stopped, in accordance with JIS B 8609, using the same method for calculating cooling tower efficiency (step S3). 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 being exerted) to the "actual inlet and outlet temperature difference" under certain operating conditions. Because the design temperature difference varies depending on the outside air conditions, it is necessary to measure the outside air temperature, relative humidity, and atmospheric pressure to understand the physical conditions of the surrounding air. Furthermore, cooling tower efficiency is significantly affected not only by the weather conditions of the surrounding environment, but also by the ventilation volume, which is the air flow around the cells and cooling tower. This is because cooling water flows through all cells 51 installed in the cooling tower 5, even when the fan 52 is not operating. Furthermore, even when the fan 52 is not operating, the surrounding air flows naturally, cooling 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. If there are multiple cells 51 that are not operating, the ventilation volume for each cell 51 can be calculated in a similar manner.

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

[0029] Conventionally, the cooling tower efficiency has been calculated by including inactive cells 51 in the operating cells 51, resulting in a small cooling tower efficiency for the cooling tower 5 as a whole. Conversely, if the cooling tower efficiency is calculated using only the operating cells 51 without considering the effect of the inactive cells 51 on the decrease in cooling water temperature, the cooling tower efficiency will be large. Therefore, a cooling tower condition evaluation method that does not include a correction step for calculating the ventilation volume in an inactive cell 51 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 condition evaluation method of the present invention. The cooling tower condition evaluation method of the present invention calculates the cooling tower efficiency of a cooling tower 5 made up of 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, if it is determined that the average cooling tower efficiency is higher than the predetermined set value (step S5 YES), the addition of water treatment agent is not actively carried out, but the water treatment agent may be added to the normal set concentration in response to the decrease in the water treatment agent due to evaporation and scattering of the cooling water. After the water treatment agent is added, the cooling tower condition evaluation method can be terminated (END).

[0031] On the other hand, if 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 to restore the cooling tower efficiency to the normal set concentration (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 condition evaluation method, and the water treatment agent is added not only to prevent fluctuations in the cooling water but also to prevent deterioration and fouling of the cooling tower 5. In this case, it is preferable to determine in advance the amount to be added that is increased compared to normal cases, or the type of water treatment agent to be added. In particular, it is preferable to set multiple cooling tower efficiency thresholds and multiple amounts of water treatment agent to be added. Alternatively, it is possible to add a different water treatment agent in addition to or instead of the normal water treatment agent. As an alternative water treatment agent, if the slime control agent normally used is an oxidizing agent, it may be more effective to use an organic slime control agent, which has a different principle of action from oxidizing agents, rather than increasing the amount. Furthermore, while commonly used scale inhibitors have a strong effect on preventing scale deposition, 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, adding a scale inhibitor with a different effect on preventing deposition can sometimes enhance the effect of preventing deposition. Furthermore, after the adding step (step S6) of adding the water treatment agent, the process proceeds to a calculation step in which the cooling tower efficiency is continuously calculated for each cell 51 based on the measured values ​​in the first and second measuring steps (step S1). Next, the process proceeds to a determination step in which 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 determined that the cooling tower efficiency of the cooling tower 5 has decreased and the performance of the cooling tower 5 has deteriorated, water treatment agents can be injected into the cooling water 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 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 terminated (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 terminated after the addition step (step S6) and then restarted as needed 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, 1.5 times the normal amount, when the cooling tower efficiency is 90% or less, or the amount of water treatment agent added can be increased to a third stage, 2.0 times the normal amount, when the cooling tower efficiency is 80% or less. Note that in the addition process (step S6), the stage in which 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 two types of water treatment agents are used, for example, one water treatment agent that is normally added and another water treatment agent are added. If 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. Repeat this process every 24 hours until the cooling tower efficiency is restored, then stop adding the water treatment agent. 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. Repeat this process every 12 hours to restore cooling tower efficiency, then stop adding the water treatment agent. In addition, if the cooling tower efficiency is 90% or less, an additional amount of another water treatment agent is added at 0.5 times the amount normally added, and if the cooling tower efficiency is 80% or less, an additional amount of another water treatment agent is added at 1.0 times the amount normally 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 that corresponds to the state of the cooling tower efficiency that has decreased.

[0034] Furthermore, the cooling tower condition evaluation method of the present invention can calculate the cooling tower efficiency for each cell. Fig. 5 is a diagram showing a flowchart illustrating the cooling tower condition 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 pre-recorded cooling tower efficiency of the cell 51 and the calculated cooling tower efficiency of the cooling tower 5. In a cooling tower 5 having multiple cells 51, an operating method is often adopted in which operating cells 51 are switched in sequence to average the operating time of each fan 52. Therefore, as the cooling tower 5 operates, the cooling tower efficiency is continuously calculated, and at the same time, by monitoring the operating cells 51 from the current values ​​operating the fans 52, the cooling tower efficiency of each cell 51 can also be calculated in the cell evaluation step. Furthermore, a recording step is provided in which the calculated cooling tower efficiency of each cell 51 is recorded. Note that the following description will be given for a cooling tower 5 with one inactive cell 51.

[0035] First, the control device 4 identifies the cell 51 that 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 efficiencies of each cell 51 of the operating cooling towers 5 have already been calculated. Furthermore, even for the first time, the cooling tower efficiencies of each cell 51 have 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 efficiencies of the operating cells 51.

[0036] Next, the calculation of the cooling tower efficiency of each cell 51 is repeated every time the operation order of each cell 51 of the cooling tower 5 is switched, thereby continuously calculating the cooling tower efficiency of each cell 51 (step S13). Furthermore, after each cell 51 is evaluated, the evaluation is recorded in the control device 4 in a recording step. 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 condition evaluation method of the present invention. Each time the operation order of each cell 51 of the cooling tower 5 is changed, the calculation of the cooling tower efficiency of the cell 51 is repeated, thereby moving on to continuously calculating the cooling tower efficiency of each cell 51 (step S13). Furthermore, the cooling tower condition evaluation method of the present invention determines whether the calculated cooling tower efficiency for each cell 51 is higher than a predetermined set value (step S14). In step S14, if 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 to the normal set concentration in response to the decrease in the water treatment agent due to evaporation and scattering of the cooling water. After the water treatment agent is added, the cooling tower condition evaluation method can be terminated (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 restore 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 drop 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 drop 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 for the cells 51. Furthermore, while repairs and renovations of cooling towers 51 are often carried out on a cell-by-cell basis to keep costs down, by understanding the cooling tower efficiency of each cell 51, it is possible to prioritize repairs and renovations of cells 51 with significant declines in capacity, thereby maximizing cost-effectiveness. Furthermore, after the addition of the water treatment agent, the cooling tower condition evaluation method can be terminated (END). However, here, after the addition step (Step S15), the process again moves to identifying the cell 51 with the oldest recorded cooling tower efficiency (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 terminated (END). As a result, when it is discovered that the cooling tower efficiency of the cooling tower 5 has decreased and the performance of the cooling tower 5 has deteriorated, water treatment agents can be injected into the cooling water to quickly restore the performance, and then the condition of the cooling tower 5 can be grasped and the performance of each cell can be evaluated individually, thereby stabilizing the performance of the cooling tower 5 and enabling continuous energy-saving operation.

[0039] Alternatively, the cooling tower 5 condition evaluation method can be terminated (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 terminated after the addition step (step S14) and then restarted 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 condition evaluation method of the present invention. A cooling tower system 100 for implementing the cooling tower condition evaluation method is connected to a heat source such as a boiler, which is the thermal load of the object to be cooled, although this is not shown. The cooling tower system 100 also includes an input device 1, communication means 2, a control device 4, a cooling tower 5 as cooling equipment 3, a circulation pump 55, and a heat exchanger 6, as well as a water supply pump (not shown). The cooling tower system 100 can also be connected to the Internet 23 by placing communication means 2 on the web.

[0041] The input device 1 has an input unit 11 through which an operator 8 inputs operating conditions for operating the cooling equipment 3. It also has a display unit 12 that displays the operating conditions input by the operator 8 and the operating status of the cooling equipment 3. The input device 1 may be directly connected to the control device 4 via a LAN line 21 without using the Internet 23. Alternatively, the input device 1 may be connected to an external data server 14 via a LAN line, telephone line, or the like to obtain necessary weather forecast information. Alternatively, the input device 1 may be connected to the control device 4 by connecting to the Internet 23 via a LAN line 22. Similarly, the Internet 23 may be connected to multiple intermediate servers, such as a weather forecast server that handles weather forecast information, a calculation processing server that performs calculations, and an intermediate server (not shown) that processes automatic control. 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 condition evaluation method. Furthermore, the cooling tower efficiency of the cooling tower 5 can be evaluated remotely to operate the cooling tower 5.

[0042] The control device 4 receives instructions for operating conditions from the input device 1 and calculates operating conditions for the cooling equipment 3 according to the received instructions. The control device 4 includes a receiving unit 42 that performs the calculations, and a control unit 41 that transmits the operating conditions to the fan 52 and circulation 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 that includes the distributed control system (DCS) is also connected to the input device 1 via the Internet 2, and efficient control can be achieved by mutual communication.

[0043] In the method for controlling the operation 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, the operating conditions that minimize the total power consumption of the fans 52 and the circulation pump 55 in the cooling equipment 3 can be found, 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 an embodiment of a system for implementing the cooling tower state evaluation method of the present invention. Cooling tower system 100 for implementing the cooling tower condition evaluation method further includes water treatment agent addition device 7. In FIG. 8 , the water treatment agent is added to pipe 53 connecting cooling tower 5 and heat exchanger 6. The water treatment agent can also be added directly to the cooling water in 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 using a measurement value by the measuring means received by the receiving unit 42, in the control unit 41. When the control device 4 determines to add a water treatment agent to the cooling tower 5, it transmits an instruction from the control device 4 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). By knowing the cooling tower efficiency of each cell 51 provided in the cooling tower 5, it is possible to repair or renovate a cell 51 whose capacity has significantly decreased. [Example]

[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 facility is equipped with a cooling tower with N cells, a circulating pump, a heat exchanger, and a control device with a measuring device for measuring the circulating cooling water, outside temperature, humidity, and atmospheric pressure, and a data collection panel.The cooling tower is also equipped with a fan, a water distribution pipe, a measuring device for measuring the frequency of the current that operates the fan, and a measuring device 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 the number of cells used in the calculation. (3) Example: The cooling tower efficiency is calculated by taking into account the ventilation volume calculated based on whether the fan of each cell is operating or not and the actual measured water temperature of the cell where the fan is not operating, and correcting the contribution.

[0048] The operating conditions for 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 operating fans 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) between February 1 and 28, and the period when the number of operating cells in the cooling tower changed. In Figure 9, the shaded areas represent periods when the specified number of cooling towers was operating, and the unshaded areas represent periods when one less than the specified number was operating.

[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, ranging from a dozen years to several decades, and if proper cooling water treatment and maintenance are performed, the decline in cooling tower efficiency is often limited to around 20-50%, even for cooling towers that have been installed for over a decade. Therefore, even for cooling towers that have been installed for over a decade, 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 affected 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 experimental condition (3), which remained almost constant throughout the measurement period, accurately calculated the cooling tower efficiency of the cooling tower including the cell compared to the other experimental conditions (1) and (2).

[0051] Next, as experimental condition (4), the cooling tower efficiency was calculated under the following conditions. Although the cooling equipment was different from those in experimental conditions (1) to (3), the cooling tower efficiency in experimental condition (4) was calculated according to the operating conditions of the cooling equipment similar to those 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 (outside 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] 200g / m of water treatment agent to prevent adhesion of dirt to the cooling water system 3 Amount of cooling water added: 62m 3 For a single-cell cooling tower with a cooling capacity of 10 ... 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 and amount of water treatment agent 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 fouling to the cooling water system. This allows the water treatment agent concentration to be increased to 300 g / m 3 By increasing the cooling tower efficiency to 100%, the cooling tower was able to recover, and stable operation was achieved with a cooling tower efficiency of 85-92% from early April to early August. The progress of cooling tower efficiency is shown in Table 1. As shown in Table 1, it was found that stable cooling tower efficiency could be achieved under experimental condition (4) even if evaporation and scattering of cooling water occurred.

[0053] [Table 1]

[0054] This demonstrates that the cooling tower condition evaluation method of the present invention can accurately calculate the cooling tower efficiency of cooling equipment. It also demonstrates that the cooling tower system of the present invention can quickly restore the performance of a cooling tower after it has deteriorated, enabling 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 Unit 42 Receiving unit 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 lowers the temperature of the cooling water by evaporating a portion of the cooling water with air; a cooling tower including a pipeline connected to a plurality of or a single of the cells and configured to allow cooling water to be externally circulated, the pipeline configured so that the cooling water is supplied from an inlet of the pipeline and discharged from an outlet of the pipeline; A cooling tower condition evaluation method for calculating a cooling tower efficiency of a cooling tower in a cooling tower system including a heat exchanger disposed at a position midway between the outlet and the inlet of the pipe of the cell and heating the cooling water, the method comprising: 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 from passing through the heat exchanger to the inlet of the pipe, a current value, power or frequency of the fan of each of the plurality of cells, and a temperature at the outlet of each of the plurality of cells; a second measuring 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 a 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, including:

2. The cooling tower condition evaluation method includes: a correction step of calculating 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 in the adjacent cell from the temperature of the cooling water at the inlet of the cooling tower and the temperature of the cooling water in any one of the cells, and correcting the cooling tower efficiency. The cooling tower condition assessment method according to claim 1 .

3. The cooling tower condition evaluation method includes:

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

5. a plurality of cells each having a fan that lowers the temperature of the cooling water by evaporating a portion of the cooling water with air; a cooling tower including a pipeline connected to a plurality of or a single of the cells and configured to allow cooling water to be externally circulated, 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; a heat exchanger disposed at a position midway between the outlet and the inlet of the pipe of the cell, for heating the cooling water, 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 from passing through the heat exchanger to the inlet of the pipe, a current value, power or frequency of the fan of each of the plurality of cells, and a temperature at the outlet of each of the plurality of cells; a second measuring 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 a 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 condition evaluation method according to claim 5, wherein after the adding step, the cooling tower efficiency is continuously calculated for each of the cells 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 the temperature of the cooling water at the inlet of the cooling tower and the temperature of the cooling water in any one of the cells, and correcting the cooling tower efficiency; 7. The cooling tower condition evaluation method according to claim 6, wherein the adding step adds a 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 the cooling tower efficiency of each cell of the cooling tower based on the pre-recorded cooling tower efficiency of the cell and the calculated cooling tower efficiency of the cooling tower; 7. The cooling tower state evaluation method according to claim 6, wherein the adding step adds a 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 adding 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 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 lowers the temperature of the cooling water by evaporating a portion of the cooling water with air; a cooling tower including a pipeline connected to a plurality of or a single of the cells and configured to allow cooling water to be externally circulated, the pipeline configured so that the cooling water is supplied from an inlet of the pipeline and discharged from an outlet of the pipeline; a heat exchanger disposed at a position midway between the outlet and the inlet of the pipeline of the cell, for heating 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 passing through the heat exchanger to the inlet of the pipe, a current value, power or frequency of the fan of each of the plurality of cells, and a temperature at the outlet 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 a cooling tower efficiency for each of the cells based on the measurements made by 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 in 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 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 comprises cell calculation means for calculating the cooling tower efficiency of each cell of the cooling tower based on a pre-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 and 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 lowers the temperature of the cooling water by evaporating a portion of the cooling water with air; a cooling tower including a pipeline connected to a plurality of or a single of the cells and configured to allow cooling water to be externally circulated, the pipeline configured so that the cooling water is supplied from an inlet of the pipeline and 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 heating the cooling water; The cooling tower 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 passing through the heat exchanger to the inlet of the pipe, a current value, power or frequency of the fan of each of the plurality of cells, and a temperature at the outlet 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 a cooling tower efficiency for each of the cells based on the measured values ​​of the first and second measurement means; a water treatment agent adding means for adding a water treatment agent to the cooling water based on the cooling tower efficiency calculated by the calculating means; and a control means for controlling the amount of water treatment agent added.

17. The cooling tower system includes:

17. The cooling tower system according to claim 16, wherein, after the water treatment agent addition means, the calculation means continuously calculates a cooling tower efficiency for each of the cells based on the measured values ​​in the first and second measurement means.

18. The control means a cooling tower efficiency corrector for correcting the cooling tower efficiency by calculating 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 in the adjacent cell from the temperature of the cooling water at the inlet of the cooling tower and the temperature of the cooling water in any one of the cells; 18. 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 means for calculating the cooling tower efficiency of each cell of the cooling tower based on a pre-recorded cooling tower efficiency of the cell and a calculated cooling tower efficiency of the cooling tower.

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

20. The cooling tower system of claim 18 or 19.

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

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