JP2020032327A - Chlorine enriching injection operation device and method - Google Patents

Abstract

To provide a chlorine enriching injection operation device and method which can perform supply of a required amount of chlorine from a seawater electrolysis device.SOLUTION: A chlorine enriching injection operation device comprises: switch transition pattern occurrence detection means 61,62 to detect occurrence of a 1→≥2 switch transition pattern which indicates that a water channel through which to inject a sodium hypochlorite solution (chlorine) of three water channels of a water intake tank is switched from a water channel involving one seawater pump in operation to a water channel involving two or more seawater pumps in operation; and conducting electric current value control means 63,64 to control a conducting electric current value of a periodic inspection rectifier by: storing an occurrence detection time of the occurrence of the 1→≥2 switch transition pattern detected by the switch transition pattern occurrence detection means 61,62; obtaining a discharge port residual chlorine concentration base value a predetermined lag time after the water channel through which to inject the sodium hypochlorite solution of the three water channels is switched to a water channel other than the water channel involving the two or more seawater pumps after the occurrence detection time; and comparing the obtained discharge port residual chlorine concentration base value with a control target value.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a chlorine-enhanced injection operation apparatus and method suitable for use in a seawater electrolysis apparatus provided in a nuclear power plant or the like.

  Nuclear and thermal power plants use seawater as cooling water. Shells, such as barnacles and mussels, are placed inside the intake channel that takes in seawater from the sea and supplies it to the condenser, and inside the discharge channel that discharges seawater that has passed through the condenser to the sea. Marine organisms easily attach. An increase in the amount of marine organisms attached may cause problems such as blocking the flow path of seawater and lowering cooling performance.

  In order to prevent such obstacles caused by the use of seawater as cooling water, heat exchanger equipment is used to inject chemicals to prevent the adhesion of marine organisms and slime, and in the condenser, A continuous thin tube washing device such as a sponge ball is used to remove attached marine organisms and slime.

  However, as pointed out in paragraph 0008 of Patent Document 3 below, when injecting a chlorinating agent such as electrolytic chlorine to prevent the adhesion of marine organisms and slime, the amount of the chlorinating agent to be injected should be as high as possible. At the same time, it is necessary to control the concentration of residual chlorine at the outlet from the lower limit of detection (eg, 0.05 mg / L by the DPD method). However, the decay of the chlorinating agent varies significantly depending on the amount of reducing inorganic and organic substances, such as ammonium salts, nitrites and ferrous ions, and planktons in seawater. Therefore, when a chlorine agent is added at a high concentration, the residual chlorine concentration at the outlet may exceed the lower limit of detection. On the other hand, if the concentration of residual chlorine at the outlet is less than the lower detection limit, the chlorine agent may not reach the effective antifouling concentration at the antifouling target location. If the chlorine agent does not reach the effective antifouling concentration, marine organisms and slime will adhere to it, reducing the degree of vacuum in the condenser and directly reducing the power generation efficiency, and reducing the heat transfer rate of the heat exchanger. Or drop.

  In addition, in the heat exchanger, marine organisms or slime may adhere to the pipes, causing a decrease in heat transfer efficiency or a rise in pipe pressure due to clogging of the heat exchanger tubes, causing damage to flange seals, peeling of lining material inside pipes, and increasing pump power. There is a concern that adverse effects may occur.

  It is known from knowledge that the amount of marine organisms and slime generated depends on the seawater temperature. In particular, it is known that plankton species breed at the same time as the seawater temperature rises in April and May, and that the pressure difference rises due to adhesion and deposition on a seawater strainer.

  Therefore, conventionally, a chemical solution has been injected by injecting a chlorine-based chemical such as a sodium hypochlorite solution (hereinafter referred to as “chlorine”) or chlorine dioxide into seawater, or by adding sodium hypochlorite from an intake port. In addition to the solution injection, a chlorine strengthening injection line was installed to reinforce the sodium hypochlorite component lost by injection from the intake by directly injecting it into the intake tank where the auxiliary equipment cooling water seawater system pump was installed, 2. Description of the Related Art Adhesion of marine organisms to the seawater side of a condenser and an auxiliary cooling water heat exchanger has been performed.

Specifically, as a chemical liquid injection method, chlorinating agents such as electrolytic chlorine and aqueous hydrogen peroxide are used as auxiliary equipment to be used in plants during regular inspections and long-term shutdowns of nuclear power plants to counter marine organisms and slime in seawater cooling water systems. Seawater from the auxiliary cooling water seawater system is passed through the heat exchanger as cooling water for the cooling water heat exchanger.
Note that the circulating water pump is often stopped for inspection while the plant is stopped.

  An auxiliary equipment cooling water seawater system pump is operated to supply seawater to the auxiliary equipment cooling water seawater system. The auxiliary equipment cooling water seawater pump is disposed in the intake tank, and the intake tank is divided into three waterways.

Auxiliary cooling seawater pumps of nuclear power plants are divided into reactor auxiliary cooling water seawater systems and turbine auxiliary cooling water seawater systems, and pumps are arranged in each intake tank.
The reactor auxiliary cooling water seawater system has two auxiliary cooling seawater pumps installed in each channel, and the turbine auxiliary cooling water seawater system has one auxiliary cooling seawater pump installed in each channel. ing.
During normal operation, one or two auxiliary cooling seawater pumps are operated in each water channel for the reactor auxiliary cooling water seawater system, and a total of three auxiliary cooling water seawater systems are used for each turbine auxiliary cooling water seawater system. Only two of the cooling seawater pumps are operating.
During the periodic inspection, the auxiliary equipment cooling seawater pumps are stopped during inspections and are operating to supply cooling water to the reactor building. There is a difference between the waterways, and the number of operating units is unbalanced between the waterways.

  During a regular inspection or during a long-term stoppage, the circulating water pump is often stopped, so the amount of supplied seawater is reduced, so that the amount of chlorine supplied by the seawater electrolyzer can be reduced. Therefore, chlorine injection on the intake side has been stopped, and adjustment has been made by chlorine injection only on the chlorine strengthening injection line on the intake tank side.

  The following Patent Document 1 utilizes the fact that there is a correlation between seawater temperature and generation of marine organisms, and obtains optimal control by controlling the electrolytic current value in proportion to the temperature, which is the process amount. A temperature sensor disposed on the seawater pipe on the electrolysis apparatus inlet side, and a control panel having an arithmetic circuit that automatically corrects the output current by a relational expression between water temperature and current efficiency based on a temperature signal detected by the temperature sensor, An output control method of a seawater electrolysis apparatus in which the output current of an electrolysis apparatus is controlled by the output of a control panel is disclosed.

Patent Literature 2 below contains marine organisms in order to chemically decompose residual chlorine in seawater that has passed through a condenser or heat exchanger with CO ₂ and reduce the amount released to the environment. In performing heat exchange with the equipment to be heat-exchanged using water, a chlorine-based chemical is injected into water for heat exchange, and then CO ₂ microbubbles are injected to thereby inject residual chlorine concentration of water released from the equipment to be heat-exchanged. A method for suppressing the adhesion of marine organisms to the heat exchange water flow path while keeping the water flow low, and a method for suppressing the adhesion of marine organisms are disclosed.

  In Patent Document 3 below, a chlorine agent and a seawater electrolyte are injected into an intake port, at least one of hydrogen peroxide and a hydrogen peroxide generator is added to an intake tank, and chlorine is supplied from the intake port to the intake tank with chlorine. Suppresses the generation of marine organisms and prevents further generation of marine organisms by using hydrogen peroxide and hydrogen peroxide generator as a strengthening injection, and reduces residual chlorine released to the environment due to the decomposition effect of chlorine by hydrogen peroxide. In order to control, the intake channel for taking in the seawater cooling water, the pump for sending the seawater cooling water from the intake channel to the condenser or the heat exchanger, and the pump and the condenser or the heat exchanger In a cooling water system that includes a pipe connecting the at least one of a chlorine agent and a seawater electrolyte to an intake channel, and at least one of hydrogen peroxide and a hydrogen peroxide generator to a pump or a pipe. Comprising, processing method of seawater cooling water is disclosed.

JP-A-2-175889 JP 2011-104586 A JP-A-2006-209855

However, since the adjustment of the chlorine injection amount is generally determined by the residual chlorine concentration at the outlet, the amount released into the environment is monitored by sampling at the outlet. At this time, it is required that the amount of release is set to the residual chlorine concentration (0.05 ppm or less) at the water outlet which is not detected by law. It is necessary to change the value of the supplied current.
This current value is determined by manual analysis of the residual chlorine concentration at the outlet, and is adjusted based on the knowledge that marine organisms are generated almost in proportion to the seawater temperature. The seawater electrolyzer operates even during regular inspections and long-term operation shutdowns. In this case, chlorine is injected while switching the injection of chlorine-reinforced injection lines in each channel at 8-hour intervals. There was a phenomenon in which the residual chlorine concentration at the outlet was not constant but increased due to the strengthening injection interval. The reason for this is that although the chlorine-reinforced injection amount and injection time are the same for each channel, if the number of operating pumps in the channel is different, the seawater transfer time to the outlet side will be different, and the residual water discharged to the outlet will be different. A phenomenon in which the chlorine concentration fluctuates without superimposing or canceling out to a constant value has been obtained as knowledge.
According to laws and regulations, the concentration is regulated by the lower limit of detection (0.05 ppm or less) from the sampling device, so a method to maintain the concentration below the detectable level even if there is a large amount of travel time of seawater discharged to the outlet is developed. Needed.

  The output control method of the seawater electrolysis apparatus described in Patent Document 1 described above is intended to automatically control the amount of chlorine injection required to kill marine organisms based on the causal relationship between seawater temperature and marine organism generation. Therefore, it seems to be effective if the circulating water pump is operated and the amount of seawater passing through each water channel is almost the same as during plant operation, but it is mainly intended to solve the problem with the present invention. It is not always effective if the number of operating seawater pumps during regular inspection is small.

Although the method for suppressing the adhesion of marine organisms described in Patent Document 2 and the method for treating seawater cooling water described in Patent Document 3 are excellent methods for chemically reducing residual chlorine, seawater electrolysis is used. In addition to the equipment, it is necessary to use a CO ₂ or hydrogen peroxide generator, and it is necessary to provide a separate control device to cope with an increase or decrease in the amount of seawater during normal operation and during regular inspection, which increases costs. There is a problem.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a chlorine-enhanced injection operation capable of supplying a required amount of chlorine from a seawater electrolysis device with a view to reducing costs while reducing the increase in the residual chlorine concentration at the time of low flow of seawater. It is to provide an apparatus and a method.

The chlorine-strengthening injection operation device of the present invention is a chlorine-strengthening for use in a seawater electrolyzer (10) for injecting a sodium hypochlorite solution produced from seawater as a raw material into an intake tank (40) divided into a plurality of waterways. An injection operation device (60), wherein the seawater electrolysis device includes: an electrolytic cell for producing the sodium hypochlorite solution; a rectifier connected to the electrolytic cell; and a sodium hypochlorite solution. An intake tank injection switching valve (30) for sequentially injecting the water into the plurality of water paths of the intake tank; the intake tank includes a plurality of seawater pumps in each of the water paths; In the plurality of water channels, the water channel into which the sodium hypochlorite solution is injected indicates that the operation number of the seawater pump is switched from one water channel to two or more water channels by the water intake tank injection switching valve. A switching transition pattern generation detecting means for detecting the occurrence of a 1 → 2 or more switching transition pattern; and an occurrence detection time when the occurrence of the 1 → 2 or more switching transition pattern is detected by the switching transition pattern occurrence detecting means. A predetermined delay from when the water channel for injecting the sodium hypochlorite solution of the plurality of water channels is switched to a water channel other than the two or more water channels by the water intake tank injection switching valve after the occurrence detection time. An outlet current chlorine concentration base value after the time is obtained, the obtained outlet water residual chlorine concentration base value is compared with a control target value, and an energizing current value control means for controlling an energizing current value of the rectifier. It is characterized by having.
Here, the water channel into which the sodium hypochlorite solution is injected may be sequentially switched at intervals of 2 hours by the water intake tank injection switching valve.
The energizing current value control means is configured to detect the occurrence of the 1 → 2 or more switching transition pattern and, if the base value of the outlet residual chlorine concentration after the delay time is larger than the control target value, When the occurrence of the switching transition pattern of 1 → 2 or more is detected and the base value of the outlet residual chlorine concentration after the delay time is smaller than the control target value, the energizing is performed. The current value may be increased by the energizing current control value.
The control target value may be a discharge port residual chlorine concentration base value immediately before the seawater temperature tends to decrease.
The plurality of water passages are three water passages, and the seawater electrolyzer produces the sodium hypochlorite solution during the periodic inspection of the equipment in which the seawater electrolyzer is installed and injects it into the water intake tank. And a seawater pump for supplying cooling water from the intake tank to the auxiliary cooling water heat exchanger (120) during the periodic inspection. An engine cooling water pump (41) and three turbine auxiliary cooling water pumps (42), wherein each of the three water channels has two reactor auxiliary cooling water pumps and one turbine auxiliary cooling water pump. An apparatus cooling water pump may be provided, and the rectifier may be a regular inspection rectifier (14) connected to the regular inspection electrolytic cell.
The chlorine-enriched pouring operation method of the present invention provides a chlorine-enhanced pouring method for use in a seawater electrolysis apparatus (10) in which a sodium hypochlorite solution produced from seawater is injected into an intake tank (40) divided into three waterways. An injection operation method, wherein the seawater electrolysis apparatus includes an electrolytic cell for producing the sodium hypochlorite solution, a rectifier connected to the electrolytic cell, and the sodium hypochlorite solution in the water intake tank. A water intake tank injection switching valve (30) for sequentially injecting the water into the three water channels, the water intake tank includes a plurality of seawater pumps in each of the water channels, and the chlorine-enhanced injection operation method comprises the steps of: One of the two water channels, into which the sodium hypochlorite solution is injected, indicates that the number of operating seawater pumps has been switched from one water channel to two or more water channels by the water intake tank injection switching valve. A first step for detecting the occurrence of the switching transition pattern, a second step of storing an occurrence detection time when the occurrence of the 1 → 2 or more switching transition pattern is detected, and Out of the three channels, the channel for injecting the sodium hypochlorite solution is switched to a channel other than the two or more channels by the water intake tank switching valve. A third step of obtaining a value, and a fourth step of controlling the current value of the rectifier by comparing the obtained base value of the residual chlorine concentration of the water outlet with a control target value. And
Here, the water channel into which the sodium hypochlorite solution is injected may be sequentially switched at intervals of 2 hours by the water intake tank injection switching valve.
In the fourth step, the 1 → 2 or more switching transition pattern is detected in the second step, and the discharge port residual chlorine concentration base value after the delay time obtained in the third step Is larger than the control target value, the energizing current value is decreased by the energizing current control value, and the 1 → 2 or more switching transition pattern is detected in the second step, and acquired in the third step. If the water outlet residual chlorine concentration base value after the delay time is smaller than the control target value, the energizing current value may be increased by the energizing current control value.

The chlorine strengthening injection operation device and method of the present invention have the following effects.
(1) The required amount of chlorine can be supplied from the seawater electrolysis apparatus while reducing the increase in the residual chlorine concentration at the time of the low flow rate of the seawater and making the concentration uniform.
(2) Cost can be reduced.

It is a figure which shows an example of the cooling water system of the condenser or heat exchanger which utilizes seawater cooling water. It is a figure for explaining a seawater pump arranged in intake tank 40. It is a figure showing composition of seawater electrolysis device 10. It is a figure for explaining a concept of chlorine strengthening injection operation control of seawater electrolysis device 10. It is a graph which shows an example of the discharge outlet residual chlorine concentration change at the time of 8 hours chlorine injection switching. It is a graph which shows an example of the water outlet residual chlorine concentration change at the time of 2 hours chlorine injection switching. It is a graph which shows an example of the water outlet residual chlorine concentration change at the time of 1 hour chlorine injection switching. It is a graph which shows an example of the water outlet residual chlorine concentration change at the time of 30 minutes chlorine injection switching. It is a graph which shows an example of the outlet chlorine concentration change at the time when the outlet chlorine concentration base value appears, and when the seawater temperature decreases. It is a figure for explaining the effect of the rectifier current control for regular detection which made the base value of the concentration of residual chlorine in the outlet immediately before the seawater temperature tends to decrease the control target value. It is a block diagram showing composition of chlorine strengthening injection operation device 60 by one example of the present invention. It is a flowchart which shows operation | movement of the seawater pump operation signal part 61. It is a flowchart which shows operation | movement of the intake tank injection switching valve control part 62. 6 is a flowchart illustrating an operation of a base value control trigger setting unit 63. It is a flowchart which shows operation | movement of the water outlet residual chlorine concentration base value acquisition / comparison control part 64.

  The above purpose is based on the water discharge port residual chlorine concentration acquired two hours after the switching operation of the two water-operated water passages is fully closed when the switching transition pattern is detected from 1 to 2 or more of the number of operating seawater pumps. This is realized by comparing the value with the control target value and controlling the current flowing through the rectifier for regular detection.

Hereinafter, an embodiment of a chlorine strengthening injection operation device and method of the present invention will be described with reference to the drawings.
The chlorine-enhanced injection operation apparatus and method of the present invention stop the circulating water pump during a periodic inspection in a seawater electrolyzer in a nuclear power plant or a thermal power plant, and release the circulating water pump while operating the auxiliary cooling water seawater pump. In order to reduce marine organisms by appropriate chlorine injection while keeping the water inlet residual chlorine concentration below the detection limit, it has the following features.
(1) In the above-described state, the chlorine-intensified injection timer is appropriately set to suppress an increase in the residual chlorine concentration at the outlet and maintain a uniform residual chlorine concentration at the outlet.
(2) Automatic control is performed in combination with appropriate energizing current value control (rectifier rectifier current control) and chlorine strengthening injection interval according to seawater conditions.

  As shown in FIG. 1, the cooling water seawater system includes a water intake tank 40 of the seawater electrolysis apparatus 10 (see FIG. 3), a condenser 110, and an auxiliary equipment cooling water heat exchanger 120 (reactor auxiliary equipment cooling water system heat source). Exchanger and turbine auxiliary cooling water system heat exchanger), a water discharge tank 130, an auxiliary equipment seawater system water discharge garden 140 for returning cooling water from the auxiliary cooling water heat exchanger 120 to the water discharge tank 130, and a discharge connection. And a tank 150.

  Here, as shown in FIG. 2, the water intake tank 40 has two seawater intake pumps 11 (for taking in cooling water (seawater) from the sea 1 via the two intake ports 2 and the intake path 3. FIG. 3), six reactor accessory coolant pumps 41 and three turbine accessory coolant pumps 42 for supplying coolant to the accessory coolant heat exchanger 120, and a condenser 110. And three circulating water pumps 43 for supplying cooling water to the pump.

The cooling water returned to the water discharge tank 130 is discharged to the sea 1 through the water discharge channel 4, the water discharge junction tank 150, and the two water discharge ports 5.
Also, each intake port 2 is provided with a screen such as a bar screen with a rake or a rotary screen for removing algae, marine organisms and other contaminants contained in seawater.

  As shown in FIG. 3, the seawater electrolysis apparatus 10 includes two (2) seawater intake pumps 11 for taking in seawater as a raw material for producing chlorine (sodium hypochlorite solution) and impurities contained in seawater. A spiral strainer 12 for removing objects.

The seawater electrolysis apparatus 10 is divided into a part used for regular inspection and a part used during normal operation.
The part used for the regular inspection is connected to a low-output electrolytic cell 13 for constant inspection connected via a spiral strainer 12 and a deaeration tank liquid level control valve 21 described later, and to the electrolytic cell 13 for regular inspection. And the output current setting unit 15 connected to the rectifier 14.
The parts used during normal operation include two high-output electrolytic cells 16 (electrolytic cells (A) and (B)) and two rectifiers 17 connected to the two electrolytic cells 16 respectively. (Rectifier (A) and rectifier (B)), and an output current setter 18 connected to two rectifiers 17.

  The seawater electrolysis device 10 includes a degassing tank 19 that functions as a device that stores the electrolytic solution (sodium hypochlorite solution) sent from the electrolytic cell 13 and the electrolytic cell 16 for regular inspection and degass hydrogen and the like. , A liquid level meter (LT) 20 for controlling the amount of water stored in the degassing tank 19 and a degassing tank liquid level control valve 21 (electrically driven), and a blower 22 for improving degassing efficiency in the degassing tank 19. And further comprising:

The seawater electrolysis apparatus 10 further includes an injection pump 23 for sending the electrolytic solution stored in the degassing tank 19 to each of the electrolytic tanks 16, each of the water intakes 2, and the water of the water intake tank 40.
The electrolytic solution is sent to each electrolytic cell 16 via a flow meter (FIS) 24 with an electrolytic cell flow switch, passes through an intake tank injection flow control valve front valve 25 (electrically driven), and then has an intake port flow switch. The liquid is fed to each intake 2 through a flow meter (FIS) 26 and each intake port injection flow control valve 27 (manual), and a flow meter (FIS) 28 with an intake tank flow switch, an intake tank injection flow control valve. The liquid is sent to the water intake tank 40 via the 29 (manual) and the intake tank injection switching valve 30 (electrically driven).
The intake tank injection switching valve 30 is switch-controlled by an intake tank injection switching valve control unit 62 (see FIG. 11) of the chlorine-enhanced injection operation device 60 described later, and the electrolyte is sequentially supplied to the A, B, and C channels of the intake tank 40. It is for injection.

  The seawater electrolysis apparatus 10 includes a seawater electrolysis apparatus control panel 51 in which a chlorine enhancement injection operation apparatus 60 is incorporated, and a water outlet residual chlorine concentration connected to the seawater electrolysis apparatus control panel 51, as devices required for the chlorine enhancement injection operation control. It further includes a sampling device 52 and an intake tank thermometer 53 installed in the intake tank 40 and connected to the seawater electrolysis device control panel 51.

Next, the concept of the chlorine enhanced injection operation control of the seawater electrolysis apparatus 10 will be described with reference to FIG.
From the operational point of view, the residual chlorine concentration in the seawater is determined from the results of manual analysis in the discharge junction tank 150 (see FIG. 1) about once a week and the continuous measurement by the sampling device 52 (see FIG. 3). The energizing current value (electrolytic current value) of the rectifier 14 for constant detection of the electrolysis apparatus 10 is determined, and adjustment is performed so that the residual chlorine concentration at the outlet is in the range of 0.02 to 0.04 ppm by the DPD method. Therefore, the current value is high in summer and low in winter.
As described above, in the related art, the operation was performed such that the concentration of residual chlorine at the outlet was controlled by manual control of the supplied current value. However, as described above, each of the channels (hereinafter referred to as “A channel”) of the water intake tank 40 during the regular inspection. , B channel and C channel "), the following phenomenon occurs when the number of operating seawater pumps becomes unbalanced.

  When chlorine-reinforced injection is performed, the sodium hypochlorite solution temporarily stays near the bottom of the water intake tank 40 because the specific gravity of the sodium hypochlorite solution is higher than that of seawater. The amount of chlorine injected into each channel is represented by injection time × injection concentration. Since the injection time and the injection concentration in each channel are constant, a constant amount of chlorine is injected evenly.

  If the number of operating seawater pumps in each channel is different, the flow rate of releasing the injected chlorine from the heat exchanger to the outlet 5 will be different, so the time to release the retained chlorine will be longer for the channels with the smaller number of operating seawater pumps. The shorter the number of operating seawater pumps, the shorter the channel. Therefore, chlorine is discharged to the discharge port 5 for a long time in the single-unit operation waterway. At this time, when switching from the single-unit operation channel to the two-unit operation channel, even if the chlorine injection into the single-unit operation channel stops, the two units remain in a state in which the chlorine retained in the water intake tank 40 is continuously discharged to the water discharge channel 4. Since the release of chlorine from the operation waterway starts, a phenomenon occurs in which the chlorine concentration is superimposed on the water outlet 5 and the residual chlorine concentration of the water outlet increases.

  If the current value of the rectifier 14 for regular detection is reduced to avoid this phenomenon, the peak of the residual chlorine concentration in the water outlet can be reduced apparently, but the required amount of chlorine may not be injected.

  It has been found that these phenomena are likely to occur when the temperature of the seawater decreases, and are likely to occur when the absolute amount of chlorine consumption decreases due to a decrease in marine organisms. It is difficult to occur when the seawater temperature rises because marine organisms and slime are actively breeding and the chlorine required for their removal is likely to be consumed, and as a result, the concentration of residual chlorine in the outlet Is due to a downward trend.

  These phenomena are observed when the water channels of the water intake tank 40 are switched at intervals of 8 hours (chlorine strengthening injection interval), and the concentration of residual chlorine at the outlet reaches a peak approximately 3 hours after the switching.

  Therefore, measures to suppress the rise in the residual chlorine concentration at the outlet were studied by avoiding the overlap of the residual chlorine concentration released and dispersing the amount of residual chlorine released from each channel.

First, the chlorine strengthening injection interval was examined.
In paragraph 0034 of Patent Document 3, the addition time of the chlorinating agent or the seawater electrolyte per day is preferably 30 minutes or more, and may be added for 24 hours, more preferably 1 to 24 hours. Describes that it may be continuous addition or intermittent addition.

  Therefore, since the intake tank 40 is divided into three channels, the chlorine-enriched injection interval was conventionally set to 8 hours. However, the chlorine-enriched injection interval was shortened, and the chlorine content of each channel of the intake tank 40 was reduced once. By reducing the absolute amount and making it easier to discharge the chlorine at the bottom of the water intake tank 40, the chlorine release continuation time after switching the water channel was shortened.

The grounds for shortening the chlorine strengthening injection interval are as follows.
With the chlorine strengthening injection intervals set to 2 hours, 1 hour and 30 minutes, the values indicated by the residual chlorine concentration measuring device of the continuous sampling device provided near the water discharge joining tank 150 were measured.
It should be noted that reducing the absolute amount of chlorine to be injected may lower the antifouling effect, and may degrade the antifouling effect due to the chlorine decomposition effect of the seawater component at the start of chlorine injection. Minutes.

Verification was performed under the following conditions as operating conditions of the seawater pump.
A channel: Reactor accessory cooling water pump 41 is operating, turbine accessory cooling water pump 42 is operating B channel: Reactor accessory cooling water pump 41 is operating C channel: Reactor accessory cooling water pump 41 is operating

In the 8-hour chlorine-strengthening injection interval (8-hour injection), as shown in FIG. 5, after switching from the C-channel (single-unit operation channel) to the A-line (two-unit operation channel), the C-channel (single-unit operation channel) It can be seen that chlorine is released while gradually decreasing from the water channel), but chlorine released from the water channel A (two-unit operation water channel) where chlorine injection has been started overlaps to form a large peak.
In addition, there is a tendency that a peak is formed in about 3 hours after switching from the B channel (single operating channel) to the C channel (single operating channel) and then gradually decreases. It turns out not to be.

  In the 2-hour chlorine strengthening injection interval (2-hour injection), as shown in FIG. 6, after switching from the C-channel (single-unit operation channel) to the A-channel (two-unit operation channel), the C-channel (single-unit operation channel) Chlorine is gradually released from the water channel), and chlorine released from the water channel A (two operating water channels) where chlorine injection has been started is superimposed, but the water outlet of the water channel C (one operating water channel) Since the residual chlorine concentration base value (the value of the residual chlorine concentration at the outlet at the time of stable operation) can be controlled so as not to be high, the peak value of the residual chlorine concentration at the outlet of the A channel (two operating channels) is the C channel (1 unit). Although this overlapped with the base value of the residual chlorine concentration at the outlet of the operating channel, the peak point could be suppressed.

  In the 1-hour chlorine strengthening injection interval (1 hour injection), as shown in FIG. 7, the residual chlorine concentration at the outlet of the three channels A to C is superimposed. It was high and did not differ much from the peak value of the residual chlorine concentration at the outlet at the 8-hour chlorine-enriched injection interval.

As shown in FIG. 8, at the 30-minute chlorine strengthening injection interval (30-minute injection), the occurrence of the peak of the residual chlorine concentration at the outlet was not eliminated, and the base value of the residual chlorine concentration at the outlet remained low.
The reason for this is that if the energizing current value is increased, the peak of the residual chlorine concentration at the outlet of the A channel (two operating channels) becomes higher due to an increase in the base value of the residual chlorine concentration at the outlet of the C channel (one operating channel). It is considered to be.

  In this way, by shortening the chlorine strengthening injection interval, by suppressing the outlet chlorine concentration base value discharged from each channel, it is possible to suppress the outlet chlorine concentration peak value even when superposition occurs. Therefore, it was found that it was possible to stabilize the base value of the residual chlorine concentration at the outlet and to suppress the peak value of the residual chlorine concentration at the outlet without greatly reducing the energizing current value.

  Therefore, it was studied to automatically adjust the energizing current value of the rectifier 14 for constant detection of the seawater electrolysis apparatus 10 so that the chlorine-enhanced injection interval was set to 2 hours and the base value of the residual chlorine concentration at the outlet was kept constant.

First, the rectifier current control for constant detection using the measured data shown in FIG. 9 and the residual chlorine concentration at the outlet shown in FIG. 10 as inputs will be described.
(1) Purpose of rectifier current control for constant detection The residual chlorine concentration at the outlet of the water outlet is determined to be an agreement value, and it must be below the detection limit (0.05 ppm in manual analysis by the DPD method). For this reason, manual sampling is performed once a week, and the supplied current value is determined so that the residual chlorine concentration at the outlet is equal to or less than the agreement value, and the adjustment is manually performed.
At that time, if the generation of marine organisms and slime is different due to changes in ocean conditions, the chlorine consumption will also be different, so even if the seawater temperature is constant, the concentration of residual chlorine at the outlet may not always be constant, so automatic control Therefore, it is necessary to automatically control the value of the supplied current that matches the ocean conditions.

(2) Arrangement of input conditions for rectifier rectifier current control For the current value, the current value is determined based on the results of one-point manual analysis at present. Therefore, when the marine conditions such as the marine organisms' prosperity and the seawater temperature change, the current value may not always be the optimal current value.
Compared to manual analysis, the continuous sampling device outputs the residual chlorine concentration associated with changes in ocean conditions in real time, making it possible to control the rectifier current for regular inspection more realistically as an input condition for setting the current value. Become. Therefore, the control target was the rectifier current control for constant detection, in which the value of the residual chlorine concentration at the outlet at stable time (base value of the residual chlorine concentration at the outlet) was used as the residual chlorine concentration.

(3) Concept of rectifier current control for constant detection Figs. 9 (a) and 9 (b) show an example of a change graph of the residual chlorine concentration at the outlet when the base value of the residual chlorine concentration at the outlet and when the seawater temperature decreases. .
During the actual measurement data period, the seawater pump unbalance operation between the water channels of the water intake tank 40 (hereinafter, referred to as “seawater pump unbalance operation between water intake tank waterways”) is occurring.
The relationship between the outlet chlorine concentration base value and the outlet chlorine concentration peak value will be described.
According to the actual measurement data shown in FIG. 9A, in August when the seawater temperature reaches the highest value, the discharge water outlet residual chlorine concentration base value is about 0.004 ppm at a current of 170 A. Since September 1, the seawater temperature has been decreasing, and the base value of the residual chlorine concentration at the outlet has been gradually increasing.
According to the actual measurement data shown in FIG. 9B, it was confirmed that the base value of the residual chlorine concentration at the outlet was gradually increased with a decrease in the seawater temperature from October 15, and it was confirmed that October 19 The seawater temperature dropped about 0.5 ° C. in 11 hours, and the peak value of the residual chlorine concentration at the outlet was significantly increased. In addition, when the base value of the residual chlorine concentration at the outlet increases, the peak value of the residual chlorine concentration at the outlet tends to increase.
From the actual measurement data described above, it can be seen that when the base value of the residual chlorine concentration at the outlet increases, the amount of increase in the peak value of the residual chlorine concentration at the outlet tends to increase.
However, paying attention to the relationship between the seawater temperature and the occurrence of the outlet chlorine concentration peak, the seawater temperature fluctuates finely, but the occurrence of the outlet chlorine concentration peak is not regular.
In summary, there is a strong correlation between a decrease in seawater temperature → a rise in the base value of the residual chlorine concentration at the outlet, and a rise in the base value of the residual chlorine concentration in the outlet → a rise in the peak value of the residual chlorine concentration in the discharge port. It was found that the increase in the peak of the residual chlorine concentration at the mouth was a relatively weak correlation.
Therefore, it can be concluded that the peak value of the residual chlorine concentration at the outlet is highly correlated with the base value of the residual chlorine concentration at the outlet.

As described above, it was considered whether or not there was a peak of the residual chlorine concentration at the outlet at the change of each parameter of the seawater temperature drop, the occurrence of marine organisms, the base value of the residual chlorine concentration at the outlet, and the operating condition of the seawater pump. Since it was found that the base value affected the peak of the residual chlorine concentration at the outlet, and the control was easy, the base value of the residual chlorine concentration at the outlet was used as the control target.
Note that the control target value of the outlet residual chlorine concentration base value varies depending on seasonal factors and marine conditions. For example, the outlet residual chlorine concentration base value immediately before the seawater temperature tends to decrease (in the above-described measured data, 0.004 ppm).

Next, the effect of the rectifier current control for regular inspection using the outlet discharge residual chlorine concentration base value immediately before the seawater temperature tends to decrease as the control target value will be described with reference to FIG.
Increase in the base value of residual chlorine concentration at the outlet due to a decrease in seawater temperature + After switching the number of operating seawater pumps from 1 to 2 units, take into account that the delay time of the peak of the residual chlorine concentration at the outlet is 2 hours, and If the chlorine concentration base value exceeds the control target value (= 0.004 ppm), control is performed to lower the energizing current value by 10 A.
As a result, as shown on the right side of FIG. 10, the energizing current value can be reduced until the number of operating seawater pumps next time is switched from one to two, so that the subsequent increase in the peak value of the residual chlorine concentration in the water outlet is suppressed. can do.
When the seawater temperature rises, the reverse control is performed.

Next, a chlorine strengthening injection operation device 60 according to an embodiment of the present invention will be described with reference to FIGS.
The chlorine-enhanced injection operation device 60 stores the time (occurrence detection time) when a switching transition pattern (1 to 2 or more switching line patterns) of 1 → 2 or more of the number of operating seawater pumps occurs, and thereafter 2 hours after the operation waterway (the waterway with two or more seawater pumps operated) is closed by the intake tank injection switching valve 30, the water outlet residual chlorine concentration base value is obtained two hours after, and the water outlet residual chlorine concentration is obtained. It is assumed that the control value is compared with the control target value of the base value, and the energizing current value of the rectifier 14 for regular detection is increased or decreased.
If the switching transition pattern of 1 → 2 or more units (that is, the seawater pump unbalance operation between the intake tank and the waterway) has been eliminated, the control is stopped.

  As shown in FIG. 11, the chlorine-enhanced injection operation device 60 includes a seawater pump operation signal unit 61, an intake tank injection switching valve control unit 62, a base value control trigger setting unit 63, and a discharge port residual chlorine concentration base value acquisition. A comparison control unit 64 is provided.

Here, the seawater pump operation signal unit 61 performs control on the assumption that the following conditions are satisfied.
(Condition 1) The switching order of the intake tank injection switching valve 30 is in the order of A channel, B channel, C channel, and A channel.
(Condition 2) Out of the three waterways, only one waterway has zero seawater pumps except the circulating water pump 43.

  Specifically, as shown in FIG. 12, the seawater pump operation signal unit 61 stores the number of operating seawater pumps in each waterway except for the circulating water pump 43 (steps S11, S21, S31), and also stores the seawater in each waterway. Monitor the number of operating pumps.

  If the number of operating seawater pumps in the own channel is 0, the monitoring of the number of operating seawater pumps in the own channel is stopped by bypassing the storage of the number of operating seawater pumps in the own channel (S12 to S14, S22 to S24, S32). To S34).

  If the number of operating seawater pumps in the own channel is one, the next target channel (for example, if the own channel is A channel, indicates channel B. Hereinafter, it will be referred to as "one-switch target channel"). ), The number of operating seawater pumps in the channel to be switched one ahead is determined to be “no problem” if the number of operating seawater pumps in the channel to be switched ahead is one. If the number is equal to or more than the number of the water tanks, it is determined that the operation is "unbalance operation of the seawater pump between the intake tanks and the waterways" (S15 to S18, S25 to S28, S35 to S38, S41).

  If the number of operating seawater pumps in the own waterway is two or more, it is left as it is (S19, S29, S39).

  If the number of operating seawater pumps in the one-way switching target channel is 0, the two-way switching target channel (for example, if the own channel is A channel, indicates channel C. Hereinafter, the "two-point switching target channel" ). The number of operating seawater pumps in the two-way switching target waterway is determined to be "no problem" if the number of operating seawater pumps in the two-way switching target waterway is one. If the number of operating units is two or more, it is determined to be "seawater pump unbalance operation between intake tank channels" (S15 to S18, S25 to S28, S35 to S38, S41).

  The seawater pump operation signal unit 61 outputs a seawater pump operation determination signal indicating the above determination to the water tank injection switching valve control unit 62.

According to the seawater pump operation determination signal input from the seawater pump operation signal unit 61, as shown in FIG. 13, if the number of operating seawater pumps in the own water channel is 0, A fully closed signal of the water intake tank injection switching valve 30 of the own water channel is transmitted to prevent the intake water tank injection switching valve 30 of the own water channel from being opened (steps S111, S121, and S132).
This is an interlock for preventing chlorine from being unnecessarily injected into a non-operated waterway and releasing high-concentration chlorine to the outlet when the seawater pump is restarted.

  Further, when an energization start signal for the constant test electrolytic tank 13 is input from outside, the intake tank injection switching valve control unit 62 determines the intake tank based on the seawater pump operation determination signal input from the seawater pump operation signal unit 61. Open / close control of the injection switching valve 30 is performed.

That is, if the intake tank injection switching valve 30 of the A channel is closed, the B and C channel intake tank injection switching valve control subroutine is started, and the intake tank injection switching valves 30 of the B and C channels are set at two-hour intervals. It is opened and closed alternately (step S112).
When the intake tank injection switching valve 30 of the B channel is closed, the A and C channel intake tank injection switching valve control subroutine is started, and the intake tank injection switching valves 30 of the C and A channels are alternately switched at 2 hour intervals. It is opened and closed (step S122).
When the intake tank injection switching valve 30 of the C channel is closed, the A and B channel intake tank injection switching valve control subroutine is started, and the intake tank injection switching valves 30 of the A and B channels are alternately switched at 2 hour intervals. It is opened and closed (step S132).

  When all the waterways are operated by one or more seawater pumps, the A, B and C waterway intake tank injection switching valve control subroutines are started, and the intake tank injection switching valves 30 of the A, B and C waterways are activated. The intake / injection tank switching valve 30 of the A channel → the intake tank / injection switching valve 30 of the B channel → the intake tank / injection switching valve 30 of the C channel → the intake tank / injection switching valve 30 of the A channel are opened and closed at intervals of 2 hours (step S141). ).

The base value control trigger setting unit 63 determines whether the peak of the residual chlorine concentration in the outlet is generated when the AND condition of the switching transition pattern of 1 → 2 or more units and the occurrence of the unbalance operation of the seawater pump between the intake tank and the water channel is generated, and thus the residual of the outlet remains. This is for storing a control start time (occurrence detection time) for suppressing the chlorine peak value.
The operation pattern of the base value control trigger setting unit 63 is divided into two, that is, when one channel is stopped and when all channels are injected, two hours after the intake tank injection switching valve 30 of the two-unit operation channel is fully closed. Obtain the stable outflow outlet residual chlorine concentration base value that appears.

  More specifically, as shown in FIG. 14, the intake tank injection switching valve control section 62 starts the B and C waterway intake tank injection switching valve control subroutine (step S211), and the seawater pump operation signal section 61 outputs "B". When "one waterway operation and two or more C waterways operation" is detected (step S212), the time when the intake tank injection switching valve 30 of the C waterway (two or more waterways operation) is fully closed is stored (S213). After activating the 2-hour chlorine-enriched injection timer (step S261), the water outlet residual concentration for obtaining the water outlet residual concentration base value 2 hours after the intake tank injection switching valve 30 of the C channel is fully closed. A base value acquisition trigger signal is output to the water outlet residual chlorine concentration base value acquisition / comparison control unit 64 (step S262).

  The intake tank injection switching valve control unit 62 starts the C and A water channel intake tank injection switching valve control subroutine (step S221), and the seawater pump operation signal unit 61 “operates one C channel and two or more A channels”. Is detected (step S222), the time when the intake tank injection switching valve 30 of the A channel (two or more operation) is fully closed is stored (S223), and the 2-hour chlorine-enhanced injection timer is started. (Step S261), a water outlet residual concentration base value acquisition trigger signal for acquiring the water outlet residual concentration base value two hours after the intake tank injection switching valve 30 of the A channel is fully closed (Step S262). .

  The intake tank injection switching valve control unit 62 starts the A and B waterway intake tank injection switching valve control subroutine (step S231), and the seawater pump operation signal unit 61 “operates one A channel and two or more B channels”. Is detected (step S232), the time when the water intake tank injection switching valve 30 of the B channel (two or more operation) is fully closed is stored (S233), and the 2-hour chlorine-enriched injection timer is started. (Step S261), a water outlet residual concentration base value acquisition trigger signal for acquiring the water outlet residual concentration base value two hours after the intake tank injection switching valve 30 of the B channel is fully closed (Step S262). .

  The intake tank injection switching valve control unit 62 starts the A, B, and C waterway intake tank injection switching valve control subroutine (step S241), and the seawater pump operation signal unit 61 outputs "one B water channel operation and two or more C water channels." If "operation", "operation of one C channel and operation of two or more A water channels" or "operation of one A channel and operation of two or more B water channels" is detected (steps S212, S222, and S232), two or more vehicles are operated. The time at which the water intake tank injection switching valve 30 is fully closed is stored (S251), and a two-hour chlorine-enhanced injection timer is started (Step S261), and two or more intake water tank injection switching valves 30 for operating water channels. Then, a water outlet residual concentration base value acquisition trigger signal for acquiring a water outlet residual concentration base value two hours after is completely closed is output (step S262).

  The water outlet residual chlorine concentration base value acquisition / comparison control unit 64 sets a single control value (hereinafter, referred to as a “conduction current control value”) of a conduction current value of the rectifier 14 for regular detection to 10 A, and sets a maximum conduction current. The value was set to 180 A, and the lower limit value of the energizing current was set to 110 A (that is, the adjustment range of the energizing current value at the time when the seawater temperature decreased was 70 A). The current value of the constant detection rectifier 14 is controlled based on the water outlet residual concentration base value after 2 hours.

  Specifically, as shown in FIG. 15, when a trigger signal for acquiring a base value of the concentration of the water outlet is input from the base value control trigger setting unit 63 (step S311), the rectifier 14 for regular detection is output from the output current setter 15. And a base value of the residual chlorine concentration of the water outlet from the water outlet residual chlorine concentration sampling device 52, and stores the obtained current value and the base value of the residual chlorine concentration of the water outlet (step S312). .

  Further, the water outlet residual chlorine concentration base value acquisition / comparison control unit 64 performs a comparison process between the acquired water outlet residual chlorine concentration base value and the control target value (= 0.004 ppm) (step S313).

  As a result, if the obtained base value of the residual chlorine concentration at the outlet is the same as the control target value, the current flowing through the rectifier 14 for regular detection is left as it is (step S314).

  On the other hand, if the acquired outlet water residual chlorine concentration base value is larger than the control target value, it is checked whether or not the acquired energizing current value is the energizing current lower limit value (= 110 A) (step S315).

As a result, if the obtained energizing current value is equal to or more than the energizing current lower limit value (= 110 A), the energizing current value lowering instruction signal instructing the energizing current value to decrease by the energizing current control value (= 10 A) is output to the output current setting device. 15 (step S316).
Thereby, the current value of the rectifier 14 for regular detection is reduced by about 10 A by the output current setting device 15.

  On the other hand, if the acquired energizing current value is the energizing current lower limit value (= 110 A), the energizing current value of the rectifier 14 for regular detection is left as it is (step S314).

  If the water outlet residual chlorine concentration base value obtained in step S313 is smaller than the control target value, it is checked whether the obtained energizing current value is the energizing current upper limit value (= 180A) (step S317).

As a result, if the obtained energizing current value is equal to or less than the energizing current upper limit value (= 180 A), the energizing current value increase instruction signal for instructing to increase the energizing current value by the energizing current control value (= 10 A) is output to the output current setting device. 15 (step S318).
As a result, the current flowing through the rectifier 14 for regular detection is increased by about 10 A by the output current setting unit 15.

  On the other hand, if the acquired energizing current value is the energizing current upper limit value (= 180 A), the energizing current value of the rectifier 14 for regular detection is left as it is (step S314).

The discharge port residual chlorine concentration base value acquisition / comparison control unit 64 repeats the above operation to constantly monitor and determine the discharge port residual chlorine concentration base value while the unbalanced number of operating units between the waterways continues. The current value of the detection rectifier 14 is controlled.
This makes it possible to control the outlet water residual chlorine concentration base value to be constant, so that it is possible to effectively and eventually suppress the outlet water residual chlorine concentration peak value.

In the above description, the chlorine strengthening injection interval is described as 2 hours, but may be other than 2 hours depending on the channel area of the power plant, the flow rate of the seawater pump, and seawater conditions.
Further, since the energized current value, the delay time, and the control target value are determined by collecting the operation data of the actual machine data, the numerical values listed here are not versatile, but are unique values confirmed by the inventor. is there.

Next, as a secondary effect, a merit of operating the chlorine strengthening injection interval in two hours will be described.
As mentioned above, marine organisms vary in reproduction depending on the seawater temperature. However, even if sunlight is irradiated on the sea surface during the day, plankton species will proliferate, and it is expected that marine organisms will not be affected by seawater temperature.
If the chlorine-enhanced injection interval is 2 hours, it will be switched more frequently during the day, so that it will not be injected into the waterway during the day than at 8 hours, and an effective antifouling effect can be expected.

  In addition, if the change in the residual chlorine concentration at the outlet can be flattened, the reference value of the supplied current value can be increased to obtain a further antifouling effect, which can contribute to the improvement of the antifouling effect. By the way, it is necessary to control the removal of barnacles and the like that strongly adhere to condensers and heat exchanger thin tubes, etc., based on knowledge, with a concentration of residual chlorine at the outlet of about 0.02 ppm, and the control target value is 0.03 ppm. If it can be operated at about ± 0.01 ppm for the whole year, it is effective.

As described above, the present invention has been described. However, the specific configuration is not limited to the above-described embodiment, and even if there is a change in design within a range not departing from the gist of the present invention, the present invention is included in the present invention. .
For example, the fixed test electrolytic cell 13 and two electrolytic cells 16 are used. However, only two electrolytic cells 16 may be used, and the degassing tank 19 may be replaced with an electrolytic solution receiving tank.
If the cost viewpoint is neglected, the minimum flow rate of the injection pump 23 is guided to the deaeration tank 19 in order to prevent the outlet side of the injection pump 23 from being temporarily shut off by switching the chlorine-reinforced injection line. A flow line may be provided.
Further, as described above, the setting of the chlorine enhanced injection timer is given as an example, and other settings are also included in the present invention.

DESCRIPTION OF SYMBOLS 1 Sea 2 Intake port 3 Intake channel 4 Outlet channel 5 Outlet port 10 Seawater electrolysis device 11 Seawater intake pump 12 Spiral strainer 13 Electrolyzer for regular inspection 14 Rectifier for regular inspection 15 Output current setting device 16 Electrolyzer 17 Rectifier 18 Output current Setting device 19 Deaeration tank 20 Liquid level gauge 21 Deaeration tank liquid level control valve 22 Blower 23 Injection pump 24 Flowmeter with electrolytic tank flow switch 25 Intake tank injection flow control valve front valve 26 Flowmeter with water intake port flow switch 27 Intake port injection flow control valve 28 Flow meter with intake tank flow switch 29 Intake tank injection flow control valve 30 Intake tank injection switching valve 40 Intake tank 41 Reactor auxiliary cooling water pump 42 Turbine auxiliary cooling water pump 43 Circulating water pump 51 Seawater electrolyzer control panel 52 Outlet residual chlorine concentration sampling device 53 Intake tank thermometer 60 Chlorine strengthening injection operation device 61 Seawater pump operation signal unit 62 Tank injection switching valve control unit 63 Base value control trigger setting unit 64 Outlet residual chlorine concentration base value acquisition / comparison control unit 110 Condenser 120 Auxiliary equipment cooling water heat exchanger 130 Drainage tank 140 Auxiliary equipment seawater system water discharge garden 150 Water discharge Joining tanks S11 to S18, S21 to S28, S31 to S38, S41, S111, S112, S121, S122, S131, S132, S141, S211 to S213, S221 to S223, S231 to S233, S241, S251, S261, S262. S311 to S318 Step

Claims (8)

A chlorine-enriched injection operation device (60) for use in a seawater electrolysis device (10) for injecting a sodium hypochlorite solution produced using seawater as a raw material into an intake tank (40) divided into a plurality of waterways,
The seawater electrolysis device,
An electrolytic cell for producing the sodium hypochlorite solution,
A rectifier connected to the electrolytic cell,
An intake tank injection switching valve (30) for sequentially injecting the sodium hypochlorite solution into the plurality of water channels of the intake tank;
The water intake tank includes a plurality of seawater pumps in each of the waterways,
The chlorine-enhanced injection operation device,
The water channel for injecting the sodium hypochlorite solution out of the plurality of water channels indicates that the number of operating seawater pumps has been switched from one water channel to two or more water channels by the intake tank injection switching valve. A switching transition pattern occurrence detecting means for detecting the occurrence of two or more switching transition patterns;
An occurrence detection time when the occurrence of the 1 → 2 or more switching transition pattern is detected by the switching transition pattern occurrence detecting means is stored, and after the occurrence detection time, the sodium hypochlorite solution is injected into the plurality of water passages. The water outlet to be obtained is obtained from a water outlet residual chlorine concentration base value after a predetermined delay time since the water channel is switched to a water channel other than the two or more water channels by the water intake tank switching valve, and the obtained water outlet water residual chlorine concentration base is obtained. Comparing the value with a control target value, a current value control means for controlling the current value of the rectifier,
A chlorine-enhanced injection operation device, comprising:   2. The chlorine-enriched injection operation device according to claim 1, wherein a water channel into which the sodium hypochlorite solution is injected is sequentially switched at intervals of 2 hours by the intake tank injection switching valve. 3. The energizing current value control means,
If the occurrence of the 1 → 2 or more switching transition pattern is detected and the water outlet residual chlorine concentration base value after the delay time is larger than the control target value, the energizing current value is reduced by the energizing current control value. ,
If the occurrence of the 1 → 2 or more switching transition pattern is detected and the outlet port residual chlorine concentration base value after the delay time is smaller than the control target value, the energized current value is reduced by the energized current control value. increase,
The chlorine-enriched injection operation device according to claim 1 or 2, wherein:   4. The chlorine-enhanced injection operation apparatus according to claim 1, wherein the control target value is a discharge port residual chlorine concentration base value immediately before the seawater temperature tends to decrease. The plurality of waterways are three waterways,
The seawater electrolyzer includes a regular test electrolytic tank (13) for producing the sodium hypochlorite solution and injecting the same into the water intake tank during a regular test of equipment in which the seawater electrolyzer is installed,
Six reactor auxiliary equipment cooling water pumps (41) and three turbines for supplying cooling water from the intake tank to the auxiliary equipment cooling water heat exchanger (120) during the regular inspection. An auxiliary cooling water pump (42),
Each of the three water channels is provided with two reactor auxiliary device cooling water pumps and one turbine auxiliary device cooling water pump,
The rectifier is a rectifier (14) for a regular test connected to the electrolytic cell for a regular test,
The chlorine-enhanced injection operation device according to any one of claims 1 to 4, characterized in that: A chlorine-enriched injection operation method for use in a seawater electrolysis apparatus (10) for injecting a sodium hypochlorite solution produced using seawater as a raw material into an intake tank (40) divided into three waterways,
The seawater electrolysis device,
An electrolytic cell for producing the sodium hypochlorite solution,
A rectifier connected to the electrolytic cell,
An intake tank injection switching valve (30) for sequentially injecting the sodium hypochlorite solution into the three water channels of the intake tank;
The water intake tank includes a plurality of seawater pumps in each of the waterways,
The chlorine-reinforced injection operation method,
The water channel for injecting the sodium hypochlorite solution among the three water channels indicates that the number of operating seawater pumps has been switched from one water channel to two or more water channels by the water intake tank injection switching valve. → a first step for detecting the occurrence of a switching transition pattern of two or more units,
A second step of storing an occurrence detection time in which the occurrence of the 1 → 2 or more switching transition pattern is detected;
After the occurrence detection time, of the three water paths, a water path for injecting the sodium hypochlorite solution is switched to a water path other than the two or more water paths by the water intake tank switching valve after a predetermined delay time. A third step of obtaining an outlet residual chlorine concentration base value;
A fourth step of controlling the current value of the rectifier by comparing the acquired outlet water residual chlorine concentration base value with a control target value;
A chlorine-enhanced injection operation method, comprising:   7. The chlorine-enriched injection operation method according to claim 6, wherein a water channel into which the sodium hypochlorite solution is injected is sequentially switched at intervals of 2 hours by the intake tank injection switching valve. In the fourth step,
In the second step, the 1 → 2 or more switching transition pattern is detected, and the discharge port residual chlorine concentration base value after the delay time acquired in the third step is smaller than the control target value. If it is larger, the current value is reduced by the current control value,
In the second step, the 1 → 2 or more switching transition pattern is detected, and the discharge port residual chlorine concentration base value after the delay time acquired in the third step is smaller than the control target value. If smaller, the energizing current value is increased by the energizing current control value,
The method of claim 6 or 7, wherein the chlorine-reinforced injection operation is performed.