JP7284634B2 - Cooling tower water quality control device and its water quality control method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cooling tower water quality control apparatus and a water quality control method thereof that easily and appropriately manages the quality of circulating water or make-up water in a cooling tower.

Various water treatment chemicals are added to the circulating water of the cooling tower to prevent corrosion of the cooling tower water system and the adhesion of scale and slime. To do this, periodically measure the quality of the circulating water and the make-up water to be supplied to the circulating water, confirm whether or not it is within the target range, and check whether the blow-drainage of the circulating water, supply of make-up water to the circulating water, It is necessary to control the amount of water treatment chemicals added.

In water quality control of cooling tower water, a method was often adopted in which managers measured the water quality of sample water from which circulating water and make-up water were taken, and confirmed whether the measured values were within the target range. . However, when there are a plurality of cooling towers on the same site and the cooling capacity is adjusted by controlling the number of operating cooling towers, the cooling towers are repeatedly operated and stopped. Therefore, when trying to measure the collected sample water, the number of measurements increases, and when the cooling tower to be measured is stopped, the cooling tower water quality differs greatly from that during operation. Therefore, if the judgment is made based on the quality of the water sampled while the machine is stopped, a correct judgment cannot be made, and there have been cases where the abnormality has been noticed too late.

A part of the circulating water in the cooling tower is sampled, the coupling current between a pair of metal electrodes immersed in the sampled water and the electrochemical current noise are measured, and the quality of the circulating water is determined based on the data. , a method for controlling the discharge amount of circulating water by a blow discharge device and/or the chemical injection amount by a water treatment chemical injection device has been proposed (see Patent Document 1).

In addition, multiple water quality parameters are measured for water sampled from water treatment facilities such as cooling towers, and measures that combine changes in multiple water quality parameters, water treatment status in water treatment facilities, and measures to be taken for water treatment facilities. Water quality management in which a water quality control device storing data refers to countermeasure data and selects the water treatment status and countermeasures corresponding to the measured water quality parameters, and the display unit displays the selected water treatment status and countermeasures. A method has been proposed (see Patent Document 2).

JP-A-10-142219 JP 2015-205237 A

There are multiple cooling towers on the same site or on adjacent sites, and if you install one water quality sensor for each cooling tower, the cost will increase, especially if you need a highly accurate sensor or an expensive sensor. Cost increases. In addition, there are cases where it is necessary to control after summarizing the measurement results of each sensor, and accurate water quality cannot be obtained due to circulating water remaining depending on the installation location of the sensors.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-described conventional circumstances, and is an object of the present invention to easily and appropriately manage the water quality of circulating water or make-up water in a cooling tower. That is, the object is to provide a cooling tower water quality control device and a water quality control method that can accurately measure the water quality of circulating water and make-up water in a cooling tower, reduce costs, and facilitate sensor maintenance. do.

That is, the present invention
(1)
Two or more cooling towers, a plurality of make-up water lines for replenishing make-up water to each of the plurality of cooling towers, and circulating water for passing circulating water circulating through the lower water tank and the upper water tank of the plurality of cooling towers In cooling tower installations with lines,
A cooling tower water quality control device for collecting circulating water or make-up water as a sample water from at least one of the make-up water line or the circulating water line and measuring the water quality of the sample water,
The sample water provided for each of the plurality of cooling towers, which is connected to at least one of the circulating water line or makeup water line of each of the plurality of cooling towers and passes the sample water. a plurality of collection lines for collecting
a plurality of solenoid valves provided in each of the plurality of collection lines;
a collection pipe connected to the plurality of collection lines and into which the sample water is introduced;
a water quality measuring unit that measures the quality of the sample water sent from the collecting pipe;
controlling to open the solenoid valve of the sampling line relating to the cooling tower to be measured among the plurality of cooling towers and to close other solenoid valves in the cooling towers other than the cooling tower to be measured among the plurality of cooling towers a control unit and
When the flow of the make-up water to the make-up water line of the cooling tower to be measured is detected, the control unit controls the electromagnetic A water quality control device for cooling tower water, characterized by controlling to open a valve .
( 2 )
When the water sample newly to be measured passes through the water quality measuring unit, the volume of the sampling line extending from the water sample sampling location to the water quality measuring unit and the volume of the collecting pipe. The water quality control device for cooling tower water according to (1) , wherein control is performed so that the water quality measurement section performs the measurement of the sample water after the water is passed for a required time or longer.
( 3 )
Water quality management of cooling tower water according to any one of (1) or ( 2 ), wherein the water quality measurement unit measures the electrical conductivity of the sample water sent from the collecting pipe. Device.
( 4 )
The control unit uses the electrical conductivity of the make-up water, the electrical conductivity caused by chemicals added to the circulating water, and the electrical conductivity of the circulating water measured by the water quality measuring unit, The water quality control device for cooling tower water according to ( 3 ), wherein the concentration factor of the circulating water in the cooling tower to be measured is calculated.
( 5 )
A water quality control method using the cooling tower water quality control device according to any one of (1) to ( 4 ),
opening the solenoid valve provided in the sampling line for the cooling tower to be measured among the plurality of cooling towers, and closing the other solenoid valves in cooling towers other than the cooling tower to be measured among the plurality of cooling towers A part of circulating water or make-up water relating to the cooling tower to be measured is supplied to the water quality measuring unit through the sampling line and the collecting pipe, and the water quality is measured by the water quality measuring unit. Cooling tower water quality control method.
and

According to the present invention, when sampling water from circulating water or make-up water of a plurality of cooling towers, by switching the flow of the sample water to the sampling line provided for each cooling tower water to be measured Only sample water collected from circulating water or make-up water is introduced into a single collection pipe through a collection line.
Since the collecting pipe is connected to a single water quality measurement unit having one sensor corresponding to each measurement parameter, one water quality measurement unit can be provided for water quality measurement of circulating water or make-up water of a plurality of cooling towers. It's easy and saves installation costs. Furthermore, since the water quality measuring unit is not directly attached to the cooling tower but is installed independently, maintenance of the sensor and the like is easy even when the cooling tower is in operation.

In particular, by passing the sample water to be measured for a certain period of time or longer before the measurement in the water quality measuring section, the sampling line, the collecting pipe, and the inside of the water quality measuring section are washed, so that the water quality can be measured with high accuracy.

1 is a schematic configuration diagram showing an example of a water quality control device for cooling tower water according to an embodiment of the present invention; FIG. This is an example in which a sampling line is connected to a circulating water line and the circulating water is sampled as water sample. FIG. 2 is a schematic configuration diagram of a water quality measuring unit of the cooling tower water quality control device according to the same embodiment; FIG. 2 is a schematic configuration diagram showing an example of a water quality control device for cooling tower water according to another embodiment from FIG. 1 of the present invention; In this example, a sampling line is connected to a circulating water line and a make-up water line provided for each cooling tower, and the circulating water or make-up water is taken as sample water.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. In addition, the present invention is not limited to the following examples.

FIG. 1 is a schematic configuration diagram showing an example of a cooling tower water quality control device 21a according to an embodiment of the present invention. Specifically, this is an example in which sampling lines 8a and 8b are connected to a circulating water line 6 and the circulating water is sampled as water sample.

The cooling tower facility 20a of FIG. 1 is provided with two cooling towers 1a and 1b, which are connected to a make-up water line 7a and a make-up water line 7b. 8a shows a water quality control device 21a for cooling tower water sampled via sampling line 8b. Sample water sampled from each cooling tower 1a, 1b through sampling lines 8a, 8b flows into a collection pipe 9. As shown in FIG.

Electromagnetic valves 3a and 3b are provided at one end of each of the collection lines 8a and 8b for collecting circulating water, and one collecting pipe 9 is connected to the other end. Sampling of sample water to be measured is started by opening either one of the solenoid valves 3a and 3b, and sampling is completed by closing the opened solenoid valve 3a or 3b. A dashed line in FIG. 1 means a control signal.

A plurality of sampling lines 8a and 8b are connected to one end of the collecting pipe 9, and a water quality measuring unit 4 is provided to the other end. The sample water introduced from the collection lines 8 a and 8 b and passed through the collecting pipe 9 passes through the water quality measuring unit 4 and is discharged through the drain line 11 .

In the water quality measurement unit 4, the sensor 14 analyzes at least one water quality parameter of the circulating water and the make-up water. Water quality parameters include, for example, electrical conductivity, pH, ion concentration such as chloride ion concentration and sulfate ion concentration, acid consumption, magnesium hardness, calcium hardness, silica concentration, iron concentration, copper concentration, ammonium ion concentration, residual Various component concentrations such as chlorine concentration, total phosphoric acid concentration, zinc concentration, polymer concentration, oxidation-reduction potential, TOC, COD, turbidity and the like can be mentioned. Among these, electrical conductivity sensors are often used.

A preferred embodiment of the water quality measuring unit is illustrated in FIG. The water quality measuring unit 4 is provided with a constant flow valve 13 for fixing the flow rate of the sample water flowing through the collection pipe 9, a sensor 14, a drainage line 11, and a manual drainage valve 12. ing.
The sample water, which has a constant flow rate by the constant flow valve 13 , passes through the sensor 14 interposed in the collection pipe 9 and is discharged from the drainage line 11 communicating with the collection pipe 9 . A manual drain valve 12 installed in a pipe communicating with the sensor 14 and the drain line 11 allows water to be drained when cleaning the sensor 14 or the like.

Various water quality parameters of the sample water are measured by the sensor 14 , and the measured values are input to the controller 5 . The control unit 5 performs various data processing using the measured values of the sensor 14, judges the water quality status of the circulating water of each of the cooling towers 1a and 1b, and issues an alarm when an abnormality in the water quality of the cooling towers 1a and 1b is detected. It can also emit an error or output an abnormality to a display for management.

The control unit 5 opens the solenoid valve of the sampling line corresponding to the circulating water of the cooling tower whose water quality is to be measured so that only the circulating water of the cooling tower whose water quality is to be measured passes through the water quality measuring unit 4, and controls the other cooling towers. The solenoid valve corresponding to is controlled not to open.

For example, when the water quality measurement target is the cooling tower 1a, the control unit 5 opens the solenoid valve 3a and controls the solenoid valve 3b so that it does not open. As a result, the circulating water of the cooling tower 1a sampled from the sampling line 8a is passed through the water quality measuring unit 4, and the circulating water of the cooling tower 1b flowing through the sampling line 8b is prevented from being mixed into the water quality measuring unit 4.

In the present invention, preferably, the control unit 5 opens the circulating water solenoid valve corresponding to the cooling tower whose water quality is to be measured to start collecting the circulating water, and the circulating water solenoid valve corresponding to the cooling tower to be measured is closed. After the opening, the waiting time is longer than the time required for the volume of the sampling line 8a from the sampling point of the sample water to the sensor 14, or the volume of the sampling line 8b and the collecting pipe 9, to pass through the water quality measuring section 4. After the time has elapsed, start measuring the water quality parameters of the sample water.

In this way, by setting a waiting time from the collection of sample water to the start of measurement, the sample water measured immediately before can be sufficiently expelled from the collection line 8a or collection line 8b, the collection pipe 9, and the water quality measurement section 4. , it is possible to accurately measure the circulating water of the next cooling tower to be measured.

The measurement time and measurement interval by each sensor are determined arbitrarily, and are determined particularly by the type of each sensor, the number of cooling towers, the load of each cooling tower, and the operating time.

The control unit 5 calculates the average value of the measured values by the sensor 14 for each of the cooling towers 1a and 1b, for example, and evaluates whether or not it falls within the target range set for each water quality parameter. The control unit 5 can be set to notify the administrator by issuing an alarm or displaying it on the management display when the measurement value is detected to be out of the target range once or a predetermined number of times.

In the control unit 5, when the electrical conductivity is measured as a water quality parameter, the electrical conductivity of the make-up water of the cooling tower, the electrical conductivity caused by the chemical when adding the chemical to the circulating water, and the water quality measurement unit It is possible to provide a function of calculating the concentration factor of the circulating water in the cooling tower to be measured using the electric conductivity of the circulating water during operation. The concentration ratio can be calculated as a value obtained by dividing the electric conductivity of the circulating water during operation by the sum of the increase in electric conductivity due to the added chemicals and the electric conductivity of the make-up water.

In addition, when the water source of make-up water supplied to a plurality of cooling towers is different, the water quality of each make-up water is evaluated in the same manner as the above-mentioned evaluation of circulating water quality. An example of a cooling tower installation 20b comprising a device 21b is shown.
The cooling tower facility 20b of FIG. 3 includes a circulating water line 6, a sampling line 8c connected to the makeup water line 7c, and a sampling line 8d connected to the makeup water line 7d.

Electromagnetic valves 3c and 3d are installed in sampling lines 8c and 8d connected to makeup water lines 7c and 7d to cooling towers 1c and 1d, respectively. Only the water sample collected from is passed through the collecting lines 8c and 8d and the collecting pipe 9 to the water quality measuring section 4. As shown in FIG.

Therefore, since the make-up water of cooling towers not subject to measurement is prevented from entering the water quality measurement unit 4, the make-up water of each cooling tower can be measured by opening and closing the solenoid valve of the sampling line connected to the make-up water line of each cooling tower. water quality can be measured with high accuracy.

In the present invention, the volume of the sampling line from the sampling point of the sample water to be measured to the collection pipe and the volume of the collection pipe are adjusted so that the water sample measured immediately before does not affect the measurement result of the water sample to be measured next time. It is preferable to start the measurement after the water has passed through the water quality measuring section for a waiting time longer than the passage time.

Especially when measuring circulating water and make-up water alternately, for example, when the previous measurement is circulating water and the next measurement is make-up water, the volume of the sampling line from the sampling point of the make-up water sample to the sensor is aggregated. The passage time necessary for the pipe volume to pass through the water quality measurement section is obtained. Next, after the previous circulating water sample measurement is completed, the water flow time from the start of water flow to the make-up water sample water sampling line to be measured next to the start of measurement in the water quality measurement section is passed. It is preferable that the waiting time is longer than 1 hour, because the sample water of the replenishing water to be measured can be used to clean the sampling line, the collection pipe, and the inside of the water quality measuring section.

In the water quality control system of the present invention, the sensor analysis results and control unit analysis data processing results are wired to an external server that determines the water treatment status of each cooling tower and selects measures to be taken for the water treatment equipment and cooling towers. Alternatively, a communication device may be provided that transmits over a wireless network.

According to the present invention, one sensor for measuring at least one water quality parameter of each circulating water and make-up water of a plurality of cooling towers may be provided for each parameter, so that the cost is reduced and the work required for measurement and maintenance. can also be reduced.

1a cooling tower 1b cooling tower 1c cooling tower 1d cooling tower 2 refrigerator 3a solenoid valve 3b solenoid valve 4 water quality measuring unit 5 control unit 6 circulating water line 7a make-up water line 7b make-up water line 7c make-up water line 7d make-up water line 8a sampling Line 8b Sampling line 8c Sampling line 8d Sampling line 9 Collection pipe 10 Pump 11 Drainage line 12 Manual drainage valve 13 Constant flow valve 14 Sensor 20a Cooling tower equipment 20b Cooling tower equipment 21a Cooling tower water quality control device 21b Cooling tower water Water quality control device

Claims (5)

Two or more cooling towers, a plurality of make-up water lines for replenishing make-up water to each of the plurality of cooling towers, and circulating water for passing circulating water circulating through the lower water tank and the upper water tank of the plurality of cooling towers Water quality control of cooling tower water, wherein circulating water or make-up water is sampled from at least one of the make-up water line or the circulating water line, and the water quality of the sample water is measured. The device is provided for each of the plurality of cooling towers, which is connected to at least one of the circulating water line and the make-up water line of each of the plurality of cooling towers and passes the sample water. a plurality of sampling lines for sampling the sample water, a plurality of solenoid valves provided in each of the plurality of sampling lines, and a collective pipe connected to the plurality of sampling lines and into which the sample water is introduced; , a water quality measuring unit for measuring the water quality of the sample water sent from the collecting pipe, and opening the solenoid valve of the sampling line for the cooling tower to be measured among the plurality of cooling towers, and opening the plurality of cooling towers a control unit that controls to close other electromagnetic valves in cooling towers other than the measurement target in the tower ,
When the flow of the make-up water to the make-up water line of the cooling tower to be measured is detected, the control unit controls the electromagnetic A water quality control device for cooling tower water, characterized by controlling to open a valve . When the water sample newly to be measured passes through the water quality measuring unit, the volume of the sampling line extending from the water sample sampling location to the water quality measuring unit and the volume of the collecting pipe. 2. A water quality control system for cooling tower water according to claim 1, wherein said water quality measuring section controls said water quality measuring unit to measure said water sample after passing water for a required time or longer. 3. The cooling tower water quality control apparatus according to claim 1, wherein the water quality measuring unit measures the electrical conductivity of the sample water sent from the collecting pipe. The control unit uses the electrical conductivity of the make-up water, the electrical conductivity caused by chemicals added to the circulating water, and the electrical conductivity of the circulating water measured by the water quality measuring unit, 4. The water quality control device for cooling tower water according to claim 3, wherein the concentration factor of the circulating water in the cooling tower to be measured is calculated. A water quality control method using the cooling tower water quality control device according to any one of claims 1 to 4 ,
opening an electromagnetic valve provided in the sampling line for the cooling tower to be measured among the plurality of cooling towers, and closing other electromagnetic valves in cooling towers other than the cooling tower to be measured among the plurality of cooling towers; Accordingly, part of the circulating water or make-up water for the cooling tower to be measured is supplied to the water quality measuring unit through the sampling line and the collecting pipe, and the water quality is measured by the water quality measuring unit. A water quality control method for cooling tower water.

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