JP6720095B2 - Cooling tower equipment and water quality control method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cooling tower facility including a cooling tower for cooling water, and a water quality management method thereof.

The cooling tower equipment generally includes a cooling tower for cooling water, a heat exchanger for exchanging heat between water and a medium cooled in the cooling tower to cool the medium, and a cooling tower and the heat exchanger. And a circulation line for circulating water. In such a cooling tower facility, scaling of the heat transfer tubes of the heat exchanger, biohowling, measures against corrosion, etc. are important from the viewpoint of maintaining heat exchange efficiency in the heat exchanger and extending the life of the heat exchanger. For this reason, in many cooling tower facilities, the quality of water circulating in the facilities is often controlled.

The following Patent Document 1 describes a water quality control device in a cooling tower facility. This water quality management device includes various sensors, a chemical injection means for injecting a treatment chemical into water, and a control device for controlling the chemical injection means. In Patent Document 1, examples of the sensor include a conductivity meter that detects the conductivity of water, an ion densitometer that detects the concentration of specific ions in water, and a makeup water flow meter that detects the flow rate of makeup water. .. In this water quality management device, the chemical injecting means is driven in accordance with various values detected by the sensor to inject the treatment chemical into the water.

JP 2004-283755 A

Even in the cooling tower facility described in Patent Document 1 described above, the bio-howling amount in the cooling tower facility can be reduced by injecting a bactericide as a kind of treatment chemical into the water circulating in the facility. However, if the disinfectant is injected unnecessarily into the water, the cost of purchasing this disinfectant increases. Therefore, it is desired to reduce the running cost of the cooling tower equipment while reducing the bio-howling amount in the cooling tower equipment.

Therefore, an object of the present invention is to provide a cooling tower facility and a water quality control method thereof that can reduce running costs while reducing the bio-howling amount.

A cooling tower facility of one aspect according to the invention for achieving the above object,
A cooling tower for cooling inflowing water, a chemical solution tank for storing a chemical solution containing a chemical for removing microorganisms contained in the water, and a chemical solution injector for injecting the chemical solution in the chemical solution tank into the water. An ATP meter for detecting the amount of ATP that is the amount of adenosine triphosphate in the water, a drug concentration meter for detecting the concentration of the drug in the water, and the ATP amount detected by the ATP meter are predetermined. If the concentration of the drug detected by the drug concentration meter exceeds a predetermined value by injecting the drug solution into the water with the drug solution injector, the drug solution injector And a control device having a chemical liquid injection control unit for stopping the injection of the chemical liquid into the water by the above . The microorganisms here include algae as well as bacteria and fungi.

As a result of the test, the inventor has found that even when many kinds of microorganisms are present in water, there is a correlation between the amount of ATP in water and the amount of microorganisms in water. In the cooling tower facility, since the chemical solution is injected into water based on the ATP amount that correlates with the amount of microorganisms in the water cooled by the cooling tower, the chemical solution is injected into the water unnecessarily while suppressing the amount of microorganisms in the water. You can avoid doing. Therefore, in the cooling tower facility, the running cost can be suppressed while reducing the amount of biofouling caused by the presence of microorganisms in water.

In the cooling tower facility, the amount of the chemical liquid to be injected into water can be managed within a range in which the corrosion of the device due to the chemical liquid can be suppressed.

In any of the above cooling tower facilities, the control device uses the previously determined correlation between the ATP amount in the water and the microbial amount in the water, with respect to the ATP amount detected by the ATP meter. It may have a microorganism amount calculation unit for obtaining the amount of microorganisms and a display unit for displaying the amount of microorganisms obtained by the amount calculation unit of microorganisms.

In the cooling tower equipment, an operator of this equipment can recognize the amount of microorganisms contained in water in the cooling tower equipment.

In any one of the above cooling tower equipment, an impurity total solubility meter for detecting the total impurity solubility in the water, and an ejector for discharging the water out of the equipment, the control device, the impurity total solubility An emission control unit for driving the ejector may be provided according to the total solubility of impurities detected by a meter.

In the cooling tower facility, it is possible to suppress an increase in the amount of ash existing in the path through which water flows in the cooling tower facility.

In any one of the above cooling tower facilities, a makeup water supply device for supplying makeup water into the water may be provided according to the amount of the water in the cooling tower.

ATP amount detection step of detecting the ATP amount which is the amount of adenosine triphosphate in the water cooled by the cooling tower, and whether or not the ATP amount detected in the ATP amount detection step is a predetermined value or more. The ATP amount determination step for determining, the drug concentration detection step for detecting the concentration of the drug for removing microorganisms contained in the water in the water, and the concentration of the drug detected in the drug concentration detection step are In the drug concentration determination step of determining whether or not it is a predetermined value or more, and the ATP amount determination step, it is determined that the ATP amount detected in the ATP amount detection step is a predetermined value or more. Then , injecting the drug solution into the water, in the drug concentration determination step, if it is determined that the concentration of the drug detected in the drug concentration detection step is equal to or higher than a predetermined value, And a chemical liquid injection step of stopping the injection.

In the water quality control method for any one of the above cooling tower facilities, the ATP amount detected in the ATP amount detection step by using a previously determined correlation between the ATP amount in the water and the amount of microorganisms in the water. You may perform the microorganism amount calculation process which calculates|requires the amount of microorganisms with respect to the amount, and the display process which displays the said microorganism amount calculated|required in the said microorganism amount calculation process.

In the water quality control method of any one of the above cooling tower equipment, the impurity total solubility detection step of detecting the impurity total solubility in the water, and according to the impurity total solubility detected in the impurity total solubility detection step, And a discharging step of discharging water to the outside of the facility.

In any one of the above-described water quality management methods for the cooling tower facility, a makeup water supply step of supplying makeup water into the water may be executed according to the amount of the water in the cooling tower.

According to one aspect of the present invention, the running cost of the cooling tower facility can be suppressed while reducing the amount of bio-howling in the cooling tower facility.

It is a systematic diagram of the plant in 1st embodiment which concerns on this invention. It is a graph which shows the relationship between the relative luminescence intensity (RFU) which shows the amount of ATP, and the number of colony forming units (CFU) which shows the amount of microorganisms. It is a flow chart which shows a medical fluid injection control routine in a first embodiment concerning the present invention. It is a flow chart which shows a circulating water replacement control routine in a first embodiment concerning the present invention. It is a system diagram of a plant in a second embodiment according to the present invention. It is a flow chart which shows a medical fluid injection control routine in a second embodiment concerning the present invention. It is a flow chart which shows a circulating water replacement control routine in a second embodiment concerning the present invention. It is a flow chart which shows the medical fluid injection control routine in the 1st modification concerning the present invention. It is a flow chart which shows the medical fluid injection control routine in the second modification concerning the present invention.

Hereinafter, various embodiments of a plant including a cooling tower facility according to the present invention will be described in detail with reference to the drawings.

"First embodiment"
1st Embodiment of the plant provided with the cooling tower equipment which concerns on this invention is described with reference to FIGS.

As shown in FIG. 1, the plant of the present embodiment includes a steam turbine facility 10, a cooling tower facility 20, and a waste liquid treatment facility 70.

The steam turbine facility 10 includes a boiler 11 that generates steam, a steam turbine 12 that is driven by steam, a generator 13 that generates power by driving the steam turbine 12, and condensate that returns steam discharged from the steam turbine 12 to water. It is provided with a vessel 14 and a water supply pump 15 for sending water from the condenser 14 to the boiler 11.

The condenser 14 has a heat transfer tube group 14a through which the circulating water cooled by the cooling tower facility 20 flows, and a barrel 14b that covers the heat transfer tube group 14a. The steam exhausted from the steam turbine 12 flows into the body 14b. This steam is cooled and condensed by heat exchange with the circulating water flowing in the heat transfer tube group 14a to become water. Therefore, this condenser 14 is a kind of heat exchanger.

The boiler 11 and the steam inlet of the steam turbine 12 are connected by a main steam line 16. The steam exhaust port of the steam turbine 12 and the steam inlet port of the condenser 14 are connected. The body 14 b of the condenser 14 and the boiler 11 are connected by a water supply line 17. The water supply line 17 is provided with a water supply pump 15. In the steam turbine facility 10, the various lines 16 and 17 described above constitute a circulation system in which water (gas or liquid) circulates. The boiler 11 is connected to a drain line 18 for discharging a part of the water that has flowed into the boiler 11. The drain line 18 is provided with a discharge valve 19. The drain line 18 may be connected to a position between the water supply pump 15 and the boiler 11 in the water supply line 17.

The cooling tower facility 20 includes a cooling tower 21 for cooling the circulating water, a condenser 14 for exchanging heat between the circulating water and steam, and a circulation pump for circulating the circulating water between the cooling tower 21 and the condenser 14. 31, a chemical liquid tank 32 in which a chemical liquid containing a drug for removing microorganisms in the circulating water is stored, a chemical liquid pump (chemical liquid injector) 33 for injecting the chemical liquid into the circulating water, and replenishment for supplying makeup water into the circulating water. A water pump (make-up water supply device) 35, a discharge valve (discharger) 36 for discharging circulating water to the outside of the cooling tower facility 20, an ATP meter 52, a drug concentration meter 53, and a control device 60 are provided. The microorganisms here include algae as well as bacteria and fungi.

The cooling tower 21 cools the circulating water by bringing the circulating water into contact with the outside air (air) to cause heat exchange between the circulating water and the outside air. In the cooling tower 21, a part of the circulating water is evaporated in the process of heat exchange between the circulating water and the outside air. The remaining circulating water is cooled by the heat of vaporization due to the evaporation of part of the circulating water. The cooling tower 21 has a casing 22, a fan 24, a sprinkler 25, and a looper 26. The lower part of the casing 22 forms a water tank 23 in which the cooled circulating water is stored. A looper 26 for taking in outside air into the casing 22 is provided on a side portion of the casing 22. A fan 24 is provided on the top of the casing 22. The fan 24 plays a role of letting the outside air flow into the casing 22 via the looper 26 and discharging the outside air and the vaporized circulating water to the outside. The sprinkler 25 is arranged inside the casing 22 and below the fan 24 and above the water tank 23. The sprinkler 25 sprinkles circulating water in the casing 22. A level gauge 51 for detecting the liquid level of the circulating water accumulated in the water tank 23 is provided on the side of the water tank 23.

The condenser 14 is a shared device between the cooling tower facility 20 and the steam turbine facility 10. The water tank 23 of the cooling tower 21 and the heat transfer tube group 14 a of the condenser 14 are connected by a cooling circulating water line 41. The circulating water cooled in the cooling tower 21 flows through the cooling circulating water line 41. The circulation pump 31 is provided in the cooling circulating water line 41. The heat transfer tube group 14a of the condenser 14 and the sprinkler 25 of the cooling tower 21 are connected by a heating circulating water line 42. The circulating water heated by the condenser 14 flows through the heated circulating water line 42. The cooling circulating water line 41 and the heating circulating water line 42 constitute a circulation system for circulating circulating water between the cooling tower 21 and the condenser 14.

The drug in the drug solution stored in the drug solution tank 32 is a surfactant for removing sodium hypochlorite as a bactericidal agent for killing microorganisms and microorganisms (including dead microorganisms) adhering to the interface such as the inner surface of the tube from the interface. And, including. In the present application, the meaning of “remove microorganisms” basically means to kill microorganisms. However, in the present application, the meaning of “removing microorganisms” may include peeling off microorganisms (including dead microorganisms) attached to the interface from the interface. In addition, some microorganisms are extracellular substances composed of polysaccharides and the like, and have characteristics such as preventing a bactericidal agent from penetrating into cells (producing a bactericidal effect). Therefore, as the bactericidal agent, a drug (auxiliary agent, erythritol or isopropylphenol) having a role of penetrating the bactericidal agent into cells may be used. Moreover, the medicine illustrated here is an example, and other medicines may be used.

The chemical liquid tank 32 and the water tank 23 of the cooling tower 21 are connected by a chemical liquid line 43. The chemical liquid pump 33 is provided in the chemical liquid line 43. Although the chemical liquid line 43 extending from the chemical liquid tank 32 is connected to the water tank 23 of the cooling tower 21 here, the chemical liquid line 43 may be connected to another place as long as the chemical liquid can be injected into the circulating water. For example, the chemical liquid line 43 extending from the chemical liquid tank 32 may be connected to the upper portion of the casing 22 of the cooling tower 21, the cooling circulating water line 41, or the like.

The makeup water source 34 and the water tank 23 of the cooling tower 21 are connected by a makeup water line 44. The makeup water pump 35 is provided in the makeup water line 44. Although the makeup water line 44 extending from the makeup water source 34 is connected to the water tank 23 of the cooling tower 21 here, if makeup water can be injected into the circulating water, the makeup water line 44 is connected to another place. Good. For example, the makeup water line 44 extending from the makeup water source 34 may be connected to the upper portion of the casing 22 of the cooling tower 21 or the like.

A drain line 46 is connected to the cooling circulating water line 41. A discharge valve 36 is provided in the drain line 46.

A water quality detection line 45 is provided in the water tank 23 of the cooling tower 21. The first end of the water quality detection line 45 and the second end opposite to the first end are both connected to the water tank 23. The water quality detection line 45 is provided with an ATP meter 52 and a drug concentration meter 53. The ATP meter 52 detects the amount of ATP, which is the amount of adenosine triphosphate (ATP) in the circulating water. ATP is a substance necessary for metabolism of energy possessed by all living things. Therefore, the presence of ATP at a certain location means that there is a living thing or a trace of the living thing at that location. In the present embodiment, the ATP amount is represented by a relative luminescence amount (RLU: Relative Light Unit) when ATP is caused to emit light by a luminescent drug containing an enzyme or the like. Therefore, the ATP meter 52 of this embodiment detects this RLU. The drug concentration meter 53 detects the concentration of the drug in the circulating water. In this embodiment, the concentration of sodium hypochlorite in circulating water is detected. Although the ATP meter 52 and the drug concentration meter 53 are provided in the water quality detection line 45 here, they may be provided in other locations as long as the water quality of the circulating water can be detected. For example, the ATP meter 52 and the drug concentration meter 53 may be provided directly in the water tank 23 of the cooling tower 21, or may be provided in the cooling circulating water line 41 or the heating circulating water line 42.

The control device 60 includes a chemical liquid injection control unit 61 that controls driving of the chemical liquid pump 33, a discharge control unit 62 that controls opening/closing driving of the discharge valve 36, and a makeup water supply control unit 63 that controls driving of the makeup water pump 35. And. The chemical injection control unit 61 stores an ATP amount, in other words, a threshold value Sa related to RLU. When the RLU detected by the ATP meter 52 becomes equal to or higher than the threshold value Sa, the chemical liquid injection control unit 61 drives the chemical liquid pump 33 and causes the chemical liquid pump 33 to inject the chemical liquid in the chemical liquid tank 32 into the circulating water.

The drainage treatment facility 70 treats water discharged from the steam turbine facility 10 and circulating water discharged from the cooling tower facility 20 to reduce the concentration of harmful substances in these waters to below the environmental standard value. This is a facility that is discharged outside the plant. A drain line 18 of the steam turbine facility 10 and a drain line 46 of the cooling tower facility 20 are connected to the waste liquid treatment facility 70.

Since the circulating water circulates in the cooling tower facility 20, the microorganisms in the circulating water gradually grow in this circulation process. As a result, biofouling occurs in the equipment in the cooling tower facility 20 with which the circulating water comes into contact. In particular, as the circulating water used for the cooling tower facility 20, not only industrial water whose water quality is controlled but also water whose quality is not controlled such as river water and lake water may be used. Therefore, many kinds of microorganisms exist in such circulating water. Therefore, the inventor conducted a test whether or not there is a correlation between RLU, which is the amount of ATP in water, and the amount of microorganisms in water, when many types of microorganisms are present in water.

In this test, an ATP inspection kit manufactured by Kikkoman Biochemifa Corporation was used. This ATP inspection kit includes a Lumitester PD-30 manufactured by the same company as the ATP meter 52. Further, in this test, water at a plurality of locations including the outdoors was used as sample water. Therefore, it is estimated that many kinds of microorganisms exist in each sample water. Furthermore, it is presumed that different microorganisms exist in each sample water.

The test results are shown in FIG. In FIG. 2, the horizontal axis is a colony forming unit (CFU), which is the number of colonies present in 1 ml of the sample. That is, the horizontal axis is the amount of microorganisms per unit sample amount. In FIG. 2, the vertical axis represents the ATP amount, that is, RLU. White circles in FIG. 2 indicate the values of each sample water. As a result of this test, the correlation coefficient r ² between RLU and CFU was 0.692. Therefore, there is a correlation between RLU and CFU. Moreover, this correlation is a positive correlation. When RFU is y and CFU existing in 1 ml is x, the correlation between RLU and CFU can be expressed by the following equation (1). The broken line in FIG. 2 is a correlation characteristic line representing the relationship represented by the equation (1).

y=0.0428x 0.6142 ^... (1)

As described above, this test revealed that the inventor has a positive correlation between the RLU in water and the amount of microorganisms in the water even when many kinds of microorganisms are present in the water. It was also found that this correlation can be expressed by the above formula (1).

The inventor has set the threshold value Sa related to the RLU stored in the chemical liquid injection control unit 61 based on the findings obtained in the above test. Specifically, first, the CFU in which the performance of the target cooling tower facility 20 may not be able to secure the target performance is determined by a test or the like. The performance of the cooling tower facility 20 here is, for example, the heat exchange rate in the condenser 14. Then, the CFU determined by the test or the like is substituted into the above equation (1) to obtain the RFU corresponding to this CFU. The threshold value Sa regarding the RLU stored in the chemical liquid injection control unit 61 is the RFU thus obtained. Therefore, when the RLU detected by the ATP meter 52 reaches the threshold value Sa, there is a high possibility that the performance of the target cooling tower facility 20 cannot secure the target performance due to the cause of biofouling.

Next, the operation of the plant described above will be described. First, the operation of the steam turbine equipment 10 will be described.

The steam generated in the boiler 11 is sent to the steam turbine 12 via the main steam line 16. When steam is supplied to the steam turbine 12, the steam turbine 12 is driven. The generator 13 generates power by driving the steam turbine 12. The steam that has driven the steam turbine 12 flows into the body 14 b of the condenser 14. This steam is cooled by the heat exchange with the circulating water flowing in the heat transfer tube group 14a of the condenser 14 to become water. This water flows into the water supply line 17 and is pressurized by the water supply pump 15. The water pressurized by the water supply pump 15 is sent to the boiler 11 via the water supply line 17.

Next, the operation of the cooling tower facility 20 will be described.

The circulating water in the water tank 23 of the cooling tower 21 flows into the cooling circulating water line 41 and is pressurized by the circulation pump 31. The water pressurized by the circulation pump 31 is sent into the heat transfer tube group 14 a of the condenser 14 via the cooling circulation water line 41. The circulating water flowing into the heat transfer tube group 14a is heated by heat exchange with the steam flowing into the body 14b of the condenser 14. The heated circulating water is sprayed from the sprinkler 25 of the cooling tower 21 into the casing 22 of the cooling tower 21 via the heated circulating water line 42. The circulating water sprinkled in the casing 22 exchanges heat with the outside air flowing into the casing 22 through the looper 26. As a result, part of the circulating water is vaporized into steam. The remaining circulating water is cooled by the heat of vaporization due to the vaporization of part of the circulating water. The outside air that has exchanged heat with the circulating water is exhausted outside the casing 22 together with the steam by the fan 24. On the other hand, the cooled circulating water temporarily accumulates in the water tank 23. This circulating water flows into the cooling circulating water line 41 as described above.

Next, the control operation of the cooling tower facility 20 will be described according to the flowcharts in FIGS. 3 and 4.

In the cooling tower facility 20, the chemical liquid injection control routine shown in the flowchart of FIG. 3 is repeatedly executed. In this chemical liquid injection control routine, first, the ATP meter 52 detects RLU, which is the ATP amount in the circulating water (S11: ATP amount detection step). The chemical liquid injection control unit 61 of the control device 60 receives this RLU and determines whether this RLU is equal to or greater than the threshold value Sa (S14: ATP amount determination step).

When the chemical injection control unit 61 determines that the RLU detected by the ATP meter 52 is not equal to or greater than the threshold value Sa, it accepts a new RLU from the ATP meter 52. On the other hand, when the chemical liquid injection control unit 61 determines that the RLU detected by the ATP meter 52 is equal to or higher than the threshold value Sa, it outputs an ON command to the chemical liquid pump 33 to drive the chemical liquid pump 33 (S15: chemical liquid injection). Starting step (chemical injection step)). By driving the chemical liquid pump 33, the chemical liquid in the chemical liquid tank 32 is injected into the circulating water of the cooling tower 21 through the chemical liquid line 43.

The drug concentration meter 53 detects the concentration of the drug in the circulating water (S16: drug concentration detection step). The chemical liquid injection control unit 61 receives the chemical liquid concentration from the chemical concentration meter 53 after outputting the ON command to the chemical liquid pump 33. The chemical solution injection control unit 61 stores a threshold value Smc relating to the chemical solution concentration. This threshold value Smc is the maximum permissible chemical concentration in the circulating water that can suppress corrosion of parts in contact with the circulating water in the cooling tower facility 20 by the chemical liquid. When the chemical solution contains sodium hypochlorite, the drug concentration meter 53 detects the concentration of sodium hypochlorite in the circulating water. The threshold value Smc in this case is, for example, 5 ppm. The chemical injection control unit 61 determines whether the chemical concentration detected by the chemical concentration meter 53 is equal to or higher than the threshold value Smc (S17: chemical concentration determination step).

When the drug solution injection control unit 61 determines that the drug concentration detected by the drug concentration meter 53 is not equal to or higher than the threshold value Smc, it accepts a new drug concentration from the drug concentration meter 53. On the other hand, when the drug solution injection control unit 61 determines that the drug concentration detected by the drug concentration meter 53 is equal to or higher than the threshold value Smc, it outputs an OFF command to the drug solution pump 33 to stop the drug solution pump 33 (S18: Chemical liquid injection stop process (chemical liquid injection process)). By stopping the chemical pump 33, the injection of the chemical into the circulating water of the cooling tower 21 is stopped.

This is the end of the series of processes of the chemical liquid injection control routine in the present embodiment.

In the cooling tower facility 20, the circulating water replacement control routine shown in the flowchart of FIG. 4 is repeatedly executed. In the cooling tower 21, part of the circulating water evaporates and is discharged to the outside, so the amount of circulating water in the cooling tower facility 20 gradually decreases. Therefore, this circulating water replacement routine includes a make-up water supply control routine for supplying make-up water to the circulating water. The ash content in the circulating water increases every time the circulating water is replenished by the replenishing water supply control routine. The ash is an inorganic material represented by a metal element such as Ca or Mg or a compound thereof. This ash adheres to the equipment in contact with the circulating water in the cooling tower facility 20 and becomes scaling. When the amount of scaling of the heat transfer tube group 14a of the condenser 14, which is a type of heat exchanger, increases, the heat exchange performance of the condenser 14 decreases. Therefore, it is preferable to discharge the circulating water containing a large amount of ash. Therefore, this circulating water replacement routine also includes a discharge control routine for discharging the circulating water containing a large amount of ash.

In the makeup water supply control routine, first, the makeup water supply control unit 63 determines whether or not the circulating water amount in the water tank 23 detected by the level meter 51 of the cooling tower 21 is the minimum allowable amount (S20: Circulating water volume judgment process). When the makeup water supply control unit 63 determines that the circulating water amount detected by the level meter 51 is not the minimum allowable amount, it receives a new circulating water amount from the level meter 51. On the other hand, when the makeup water supply control unit 63 determines that the circulating water amount detected by the level meter 51 is the minimum allowable amount, it outputs an ON command to the makeup water pump 35 to drive the makeup water pump 35 ( S21: Make-up water supply start step (make-up water supply step)). By driving the makeup water pump 35, makeup water from the makeup water source 34 is supplied to the circulating water in the cooling tower 21 through the makeup water line 44.

After outputting the ON command to the makeup water pump 35, the makeup water supply control unit 63 determines whether or not the circulating water amount detected by the level meter 51 is the maximum allowable amount (S22: circulating water amount determining step). ). When the makeup water supply control unit 63 determines that the circulating water amount detected by the level meter 51 is the maximum allowable amount, it outputs an OFF command to the makeup water pump 35 to stop the makeup water pump 35 (S23: Make-up water supply stop process (make-up water supply process)). By stopping this makeup water, the supply of makeup water to the circulating water in the cooling tower 21 is stopped.

With the above, a series of processes in the makeup water supply control routine is completed. This makeup water supply control routine is repeatedly executed as described above.

In the discharge control routine, first, the discharge control unit 62 determines whether or not it is the circulating water discharge timing (S25: discharge timing determination step). As described above, the ash content in the circulating water increases every time the circulating water is supplemented with makeup water. For this reason, the period from the previous discharge time to the next discharge is set in advance. The discharge control unit 62 determines whether or not it is the discharge time, depending on whether or not a predetermined period has elapsed since the previous discharge time.

The discharge control unit 62 repeatedly executes this determination until it determines that it is the discharge timing. When the discharge control unit 62 determines that the discharge time has come, it outputs an open command to the discharge valve 36 to open the discharge valve 36 (S26: discharge start process (discharge process)). When the discharge valve 36 is opened, a part of the circulating water flowing through the cooling circulating water line 41 flows out to the drainage treatment facility 70 via the drainage line 46.

After outputting the opening command to the discharge valve 36, the discharge control unit 62 determines whether or not the circulating water amount detected by the level meter 51 of the cooling tower 21 has reached the allowable minimum amount (S27: circulating water amount determination step). .. When the discharge control unit 62 determines that the circulating water amount detected by the level meter 51 has reached the allowable minimum amount, it outputs a close command to the discharge valve 36 to cause the discharge valve 36 to close (S28: stop discharge). Process (discharging process)). When the discharge valve 36 is closed, the discharge of circulating water is stopped.

This is the end of the series of processes in the discharge control routine. This discharge control routine is also repeatedly executed as described above. When the amount of circulating water in the cooling tower 21 reaches the allowable minimum amount in the execution of the discharge control routine, the makeup water is supplied to the circulating water by executing the makeup water supply control routine.

As described above, the waste liquid treatment facility 70 treats the water discharged from the steam turbine facility 10 and the circulating water discharged from the cooling tower facility 20, and determines the concentration of harmful substances and the like in these water as environmental standards. Reduce it to less than the value and discharge it outside the plant. Specifically, the waste liquid treatment facility 70 performs a process of removing ash contained in water discharged from the steam turbine facility 10 and circulating water discharged from the cooling tower facility 20. Furthermore, when the inflowing water contains sodium hypochlorite, the drainage treatment facility 70 reduces the concentration of sodium hypochlorite in the water discharged out of the plant to, for example, 0.1 ppm or less, and then removes this water. Discharge outside the plant.

As described above, in the present embodiment, the chemical solution is injected into the circulating water based on the ATP amount having a correlation with the amount of the microorganisms in the circulating water. Therefore, while suppressing the amount of the microorganisms in the circulating water, it is unnecessary in the circulating water. It is possible to avoid injecting a drug solution. Therefore, in the present embodiment, it is possible to reduce the running cost of the cooling tower facility 20 while reducing the amount of biofouling in the cooling tower facility 20.

The amount of microorganisms in the circulating water can also be reduced by frequently replacing the circulating water. However, in the present embodiment, the amount of microorganisms is reduced by injecting the chemical solution into the circulating water based on the amount of ATP in the circulating water, so that it is possible to suppress an increase in the amount of makeup water supplied to the circulating water. Therefore, in this embodiment, also from this viewpoint, the running cost of the cooling tower facility 20 can be suppressed.

"Second embodiment"
A second embodiment of the plant including the cooling tower facility according to the present invention will be described with reference to FIGS.

As with the plant of the first embodiment, the plant of the present embodiment also includes a steam turbine facility 10, a cooling tower facility 20a, and a waste liquid treatment facility 70, as shown in FIG. The steam turbine equipment 10 and the waste liquid treatment equipment 70 of the present embodiment are the same as the steam turbine equipment 10 and the waste liquid treatment equipment 70 of the first embodiment. On the other hand, the cooling tower facility 20a of this embodiment is different from the cooling tower facility 20 of the first embodiment.

The cooling tower facility 20a of this embodiment includes a total impurity solubility meter 54 in addition to the configuration of the first embodiment. In the following, the total solubility of impurities will be referred to as TDS (Total Dissolved Solid). The TDS meter 54 detects TDS in circulating water. The TDS meter 54 is provided in the water quality detection line 45. As the TDS meter 54, for example, an electric conductivity meter that detects the electric conductivity of circulating water can be used. Although the TDS meter 54 is provided in the water quality detection line 45 here, it may be provided in another location as long as the TDS of the circulating water can be detected. For example, the TDS meter 54 may be provided directly in the water tank 23 of the cooling tower 21, or may be provided in the cooling circulating water line 41 or the heating circulating water line 42.

The control device 60a of the present embodiment has a microorganism amount calculation unit 64 and a display unit 65 in addition to the configuration of the control device 60 of the first embodiment. The microbial amount computing unit 64 obtains the microbial amount according to the ATP amount detected by the ATP meter 52. The display unit 65 displays this amount of microorganisms.

Also in the cooling tower facility 20a of the present embodiment, a chemical liquid injection control routine basically similar to the chemical liquid injection control routine of the first embodiment is repeatedly executed. However, the drug injection control routine of the present embodiment differs from the drug injection control routine of the first embodiment in that the display unit 65 displays the amount of microorganisms.

As shown in the flowchart of FIG. 6, also in the chemical liquid injection control routine of the present embodiment, first, the ATP meter 52 detects RLU, which is the ATP amount in the circulating water (S11: ATP amount detection step). The microorganism amount computing unit 64 and the chemical liquid injection control unit 61 of the control device 60a receive this RLU.

When receiving the RLU from the ATP meter 52, the microbial amount calculating unit 64 uses the above equation (1) to obtain CFU, which is the microbial amount corresponding to this RLU (S12: microbial amount calculating step). The display unit 65 displays this CFU (S13: display step).

Upon receiving the RLU from the ATP meter 52, the chemical injection control unit 61 determines whether or not this RLU is equal to or larger than the threshold value Sa (S14: ATP amount determination step), as in the first embodiment.

Hereinafter, as in the chemical liquid injection control routine of the first embodiment, the processing of S15 to S18 is executed. That is, the chemical liquid injection control routine of the present embodiment is obtained by adding the microorganism amount calculation step (S12) and the display step (S13) to the chemical liquid injection control routine of the first embodiment.

As described above, in the present embodiment, since the amount of microorganisms in circulating water is displayed on the display unit 65, the plant operator can recognize the amount of microorganisms in circulating water. Therefore, for example, even if the chemical liquid charging step (S15 to S18) is executed due to some trouble, but the amount of microorganisms does not decrease, the operator can detect this trouble early. The trouble may be, for example, a trouble in which the water quality of the makeup water source 34 is changed and microorganisms cannot be sufficiently removed by the current medicine, or a trouble in which the medicine is not put in the chemical liquid tank 32.

Also in the cooling tower facility 20a of the present embodiment, the circulating water replacement control routine basically similar to the circulating water replacement control routine of the first embodiment is repeatedly executed. As shown in the flowchart of FIG. 7, the makeup water supply control routine (S20 to S23) in the circulation water replacement control routine of the present embodiment is the makeup water supply control routine (S20 to S23 in the circulation water replacement control routine of the first embodiment. It is similar to S23). On the other hand, in the discharge control routine of the circulating water replacement control routine of the present embodiment, the condition for opening the discharge valve 36 is different from that of the first embodiment.

In the discharge control routine of this embodiment, first, the TDS meter 54 detects the TDS in the circulating water (S24: TDS detection step). The discharge control unit 62a of the control device 60a receives this TDS and determines whether this TDS is equal to or greater than a predetermined threshold Sc (S25a: TDS determination step).

The discharge control unit 62 repeatedly executes this determination until it determines that TDS is equal to or higher than the threshold Sc. When the discharge control unit 62a determines that TDS is equal to or more than the threshold value Sc, it outputs an opening command to the discharge valve 36 to open the discharge valve 36 (S26: discharge start step (discharge step)). When the discharge valve 36 is opened, a part of the circulating water flowing through the cooling circulating water line 41 flows into the drainage treatment facility 70 via the drainage line 46.

Hereinafter, similarly to the emission control routine of the first embodiment, the processes of S27 and S28 are executed.

As described above, in the present embodiment, since the circulating water is discharged according to the TDS in the circulating water in the circulating water, the amount of ash in the circulating water can be managed more appropriately than in the first embodiment. Therefore, in the present embodiment, it is possible to suppress an increase in the amount of scaling in the cooling tower facility 20a and suppress the amount of make-up water supplied to the circulating water.

"Modification"
Hereinafter, various modifications of the above embodiment will be described.

First, with reference to FIG. 8, a first modified example of the chemical liquid injection control routine of the first embodiment will be described.

Also in the chemical liquid injection control routine of the present modification, the ATP meter 52 detects the RLU which is the ATP amount in the circulating water as in the chemical liquid injection control routine of the first embodiment (S11: ATP amount detection step). The chemical liquid injection control unit 61 of the control device 60 receives this RLU and determines whether this RLU is equal to or greater than the threshold value Sa (S14: ATP amount determination step).

When the chemical injection control unit 61 determines that the RLU detected by the ATP meter 52 is not equal to or greater than the threshold value Sa, it accepts a new RLU from the ATP meter 52. On the other hand, when the chemical liquid injection control unit 61 determines that the RLU detected by the ATP meter 52 is equal to or higher than the threshold value Sa, it outputs an ON command to the chemical liquid pump 33 to drive the chemical liquid pump 33 (S15: chemical liquid injection). Starting step (chemical injection step)). By driving the chemical liquid pump 33, the chemical liquid in the chemical liquid tank 32 is injected into the circulating water of the cooling tower 21 through the chemical liquid line 43.

The above processing (S11, S14, S15) is the same as the chemical liquid injection control routine of the first embodiment.

After outputting the ON command to the chemical liquid pump 33, the chemical liquid injection control unit 61 determines whether or not the injected chemical liquid amount reaches a predetermined threshold value Smv (S17a: injected chemical liquid amount determination step). The threshold value Smv relating to the amount of liquid medicine is stored in the liquid medicine injection control unit 61. This threshold value Smv is, for example, the amount of the chemical liquid which is assumed not to exceed the aforementioned maximum allowable chemical liquid concentration when the chemical liquid is injected into the circulating water. When a level meter for detecting the liquid level of the drug solution stored in the drug solution tank 32 is provided in the drug solution tank 32, the drug solution injection control unit 61 determines the amount of the drug solution injected from the liquid level of the drug solution detected by the level meter. To get Further, when a flow meter is provided in the chemical liquid line 43, the chemical liquid injection control unit 61 obtains the injected chemical liquid amount from the flow rate of the chemical liquid detected by this flow meter. When the chemical liquid pump 33 is a metering pump, the amount of injected chemical liquid is obtained from the driving time of the chemical liquid pump 33 and the like.

When the chemical injection control unit 61 determines that the amount of the injected chemical reaches the threshold value Smv, it outputs an OFF command to the chemical pump 33 to stop the chemical pump 33 (S18: chemical injection stop step (chemical injection step)). .. By stopping the chemical pump 33, the injection of the chemical into the circulating water of the cooling tower 21 is stopped.

This is the end of the series of processes of the chemical liquid injection control routine in the present modification.

As described above, in the present modification, the injection amount of the drug solution can be managed without providing the drug concentration meter 53. Note that the drug concentration meter 53 may also be provided in this modification. In this case, in the process of executing the chemical liquid injection control routine in the present modification, if the chemical concentration exceeds the above-mentioned maximum allowable chemical liquid concentration for some reason, the chemical liquid pump 33 may be stopped at that point.

Next, with reference to FIG. 9, a second modification of the chemical liquid injection control routine of the first embodiment will be described.

In the chemical liquid injection control routine of this modified example, first, the chemical liquid injection control unit 61 determines whether or not it is the detection time of the ATP amount (S10: ATP detection time determination step). The chemical liquid injection control unit 61 determines whether or not the ATP amount detection time has come, depending on whether or not a predetermined time has elapsed from the previous ATP amount detection time.

At the detection time of the ATP amount, the chemical liquid injection control unit 61 receives the RLU which is the ATP amount from the ATP meter 52 (S11: ATP amount detection step). The chemical liquid injection control unit 61 calculates the injected chemical liquid amount according to this RLU (S14b: chemical liquid amount calculation step). If the RTP, which is the amount of ATP in the circulating water, is known, the amount of microorganisms in the circulating water can be calculated using the above formula (1). If the amount of microorganisms in the circulating water is known, a predetermined formula can be used to determine the amount of drug solution that matches this amount of microorganisms. Therefore, the chemical liquid injection control unit 61 of the present modification obtains the chemical liquid injection amount from the ATP meter 52 according to the RLU, using an equation that defines the relationship between the RTP that is the ATP amount in the circulating water and the chemical liquid injection amount.

When the chemical liquid injection control unit 61 determines the injected chemical liquid amount, it outputs an ON command to the chemical liquid pump 33 to drive the chemical liquid pump 33 (S15: chemical liquid injection start step (chemical liquid injection step)). By driving the chemical liquid pump 33, the chemical liquid in the chemical liquid tank 32 is injected into the circulating water of the cooling tower 21 through the chemical liquid line 43.

After outputting the ON command to the chemical liquid pump 33, the chemical liquid injection control unit 61 determines whether or not the injected chemical liquid amount has become the injected chemical liquid amount obtained by the previous calculation (S17b: injected chemical liquid amount determination step). .. The chemical liquid injection control unit 61 obtains the chemical liquid amount to be injected by the method described above in the first modification.

When the chemical liquid injection control unit 61 determines that the injected chemical liquid amount has reached the injected chemical liquid amount obtained by the previous calculation, it outputs an OFF command to the chemical liquid pump 33 to stop the chemical liquid pump 33 (S18: stop chemical liquid injection). Process (chemical solution injection process)). By stopping the chemical pump 33, the injection of the chemical into the circulating water of the cooling tower 21 is stopped.

This is the end of the series of processes of the chemical liquid injection control routine in the present modification.

As described above, in the present modification, the injection of the drug solution is performed without providing the drug concentration meter 53 and without setting the threshold value Sa related to the ATP amount as in the above-described embodiments and the first modification. You can manage the quantity. Therefore, as can be understood from the first embodiment, the first modified example, and the present modified example, in the present invention, any method can be used as long as the injection of the chemical liquid is controlled according to the ATP amount detected by the ATP meter 52. Thus, the injection of the drug solution may be controlled.

Note that the drug concentration meter 53 may also be provided in this modification. In this case, in the process of executing the chemical liquid injection control routine in the present modification, if the chemical concentration exceeds the above-mentioned maximum allowable chemical liquid concentration for some reason, the chemical liquid pump 33 may be stopped at that point. Further, also in the present modified example and the first modified example, the amount of microorganisms may be displayed on the display unit 65 as in the second embodiment.

The makeup water supply device of each of the above-described embodiments and each modification includes the makeup water pump 35, the level meter 51, and the makeup water supply control unit 63. However, the makeup water supply device is, for example, a float valve having a float that moves up and down in response to a change in the liquid level in the water tank 23, and a valve that opens and closes in response to the vertical movement of the float. You may comprise a feeder.

The chemical liquid injectors of the above-described respective embodiments and modifications are configured to have a chemical liquid pump 33. However, the chemical liquid injector may be composed of a valve provided in the chemical liquid line 43.

The ejector of each of the above-described embodiments and each of the modified examples is configured to include the ejection valve 36. However, the ejector may be a pump provided in the drain line 46.

The cooling tower facility of each of the above embodiments and each modification is a facility for cooling the circulating water heated by the condenser 14. However, the cooling tower facility of the present invention is not limited to the facility for cooling the circulating water heated by the condenser. The cooling tower facility of the present invention may be, for example, a facility that cools the circulating water heated by heat exchange with the refrigerant in the condenser of the refrigerator.

10: Steam turbine equipment 11: Boiler 12: Steam turbine 13: Generator 14: Condenser 14a: Heat transfer tube group 14b: Body 15: Water supply pump 16: Main steam line 17: Water supply line 18: Drain line 19: Discharge valve 20, 20a: Cooling tower equipment 21: Cooling tower 22: Casing 23: Water tank 24: Fan 25: Sprinkler 26: Looper 31: Circulation pump 32: Chemical solution tank 33: Chemical solution pump (chemical solution injector)
34: Make-up water source 35: Make-up water pump (make-up water supply device)
36: discharge valve (discharger)
41: cooling circulating water line 42: heating circulating water line 43: chemical liquid line 44: makeup water line 45: water quality detection line 46: drainage line 51: level meter 52: ATP meter 53: drug concentration meter 54: total impurity solubility meter ( TDS meter)
60, 60a: control device 61: chemical liquid injection control unit 62, 62a: discharge control unit 63: makeup water supply control unit 64: microorganism amount calculation unit 65: display unit 70: waste liquid treatment facility

Claims (8)

A cooling tower that cools the incoming water,
A drug solution tank in which a drug solution containing a drug for removing microorganisms contained in the water is stored,
A liquid medicine injector for injecting the liquid medicine in the liquid medicine tank into the water,
An ATP meter for detecting the amount of ATP, which is the amount of adenosine triphosphate in the water,
A drug concentration meter for detecting the concentration of the drug in the water,
The concentration of the drug detected by the drug concentration meter is caused by injecting the drug solution into the water by the drug injector under the condition that the amount of ATP detected by the ATP meter is equal to or more than a predetermined value. When is equal to or more than a predetermined value , a control device having a chemical liquid injection control unit for stopping the injection of the chemical liquid into the water by the chemical liquid injector,
Cooling tower installation comprising a. The cooling tower facility according to claim 1 ,
The control device is
Using a pre-determined correlation between the amount of ATP in the water and the amount of microorganisms in the water, a microbial amount computing unit for obtaining a microbial amount for the ATP amount detected by the ATP meter,
A display unit for displaying the amount of microorganisms obtained by the microorganism amount calculation unit,
Has,
Cooling tower equipment. The cooling tower facility according to claim 1 or 2 ,
A total impurity solubility meter for detecting the total solubility of impurities in the water,
A discharger for discharging the water out of the facility,
Equipped with
The control device has an emission control unit that drives the ejector according to the total impurity solubility detected by the total impurity solubility meter.
Cooling tower equipment. In cooling tower installation according to any one of claims 1 or et 3,
Depending on the amount of the water in the cooling tower, a makeup water supply device for supplying makeup water into the water,
Cooling tower equipment. An ATP amount detection step of detecting an ATP amount, which is the amount of adenosine triphosphate in water cooled by the cooling tower,
An ATP amount determination step of determining whether or not the ATP amount detected in the ATP amount detection step is a predetermined value or more;
A drug concentration detection step of detecting the concentration of the drug in the water for removing microorganisms contained in the water ,
A drug concentration determination step of determining whether or not the concentration of the drug detected in the drug concentration detection step is equal to or greater than a predetermined value,
In the ATP amount determination step, when it is determined that the ATP amount detected in the ATP amount detection step is equal to or more than a predetermined value, the chemical solution is injected into the water, and in the drug concentration determination step, When it is determined that the concentration of the drug detected in the drug concentration detection step is equal to or higher than a predetermined value, a chemical solution injection step of stopping the injection of the chemical solution,
Water quality management method of cooling tower equipment to implement . The water quality control method for a cooling tower facility according to claim 5 ,
Using a pre-determined correlation between the amount of ATP in the water and the amount of microorganisms in the water, a microbial amount calculating step of obtaining a microbial amount for the ATP amount detected in the ATP amount detecting step,
A display step of displaying the amount of microorganisms obtained in the microorganism amount calculation step,
Water quality management method of cooling tower equipment to implement. The water quality control method for cooling tower equipment according to claim 5 or 6 ,
An impurity total solubility detection step of detecting the total solubility of impurities in the water,
According to the total impurity solubility detected in the total impurity solubility detection step, a discharge step of discharging the water out of the facility,
Water quality management method of cooling tower equipment to implement. The water quality control method for a cooling tower facility according to any one of claims 5 to 7 ,
According to the amount of the water in the cooling tower, to perform a makeup water supply step of supplying makeup water into the water,
Water quality management method for cooling tower equipment.

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