JP2009216495A - Water treatment device and water treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To materialize water treatment with impurity ion demineralization/purification load, ammonia consumption, and heat loss reduced, by removing impurities contained in treated water through electric demineralization treatment at a high temperature while holding and reusing most of inlet chemical of high concentration contained in the treated water, thus allowing efficient operation of a nuclear power plant. <P>SOLUTION: In this water treatment device, the treated water containing ozonic gas is introduced into at least one reaction vessel 7 to oxidize at least one of contained component of the treated water in the reaction vessel 7. This treatment device includes a pressurizing vortex flow pump 3 for sucking ozone generated in an ozone generator 2 and the treated water to send them out to the reaction vessel, a pressure regulating member 6 provided below the reaction vessel 7, and a pressurizing pipe 4 provided between the flow pump 3 and the regulating member 6 for pressurizing the treated water containing the ozonic gas. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a water treatment technique in a nuclear power plant or a thermal power plant, and more particularly to a water treatment apparatus and a water treatment method used for secondary water in a pressurized water nuclear power plant or system water in a thermal power plant.

  In general, in a pressurized water power plant, a steam generator is divided into a primary system and a secondary system. The steam generator generates heat from the high-temperature high-pressure water generated in the primary reactor, and this heat-exchanged heat is generated. Thus, steam is generated from the secondary system water, the steam is sent to the secondary system steam turbine, and the steam turbine is driven to generate electricity.

  The steam that has driven the steam turbine is subsequently introduced into the condenser, where it is cooled and condensed in the condenser to become condensate. This condensate is subjected to demineralization treatment for removing ions with an ion exchange resin or the like in a condensate demineralizer as necessary, and then heated by a heater of a power plant system and supplied to a steam generator.

  Water supplied to the steam generator is injected with a chemical injection material from the viewpoint of suppressing corrosion of structural materials (piping and equipment) in the reactor secondary system of the power plant system. Among these, ammonia or an amine compound is used as a pH adjuster, and hydrazine is used as an oxygen scavenger.

  On the other hand, in the steam generator, impurities such as ions and corrosion products brought into the reactor secondary system, which is the power plant system, are concentrated, so corrosion of the heat transfer tubes in the steam generator and reduced heat transfer It is a factor to cause. For this reason, operation which discharges a part of water in a steam generator (blowdown) is performed.

  Blow-down water from the steam generator is guided and purified by existing water purification equipment such as a condensate demineralizer. After the pH adjusting agent, which is a drug injection substance contained in the blowdown water, is removed by the desalting process of the condensate demineralizer, a new drug injection substance is separately injected. Removing the pH adjusting agent with the condensate demineralizer and injecting a new drug separately increases the ion removal load in the condensate demineralizer and increases the drug injection cost.

  Therefore, a condensate demineralizer (condensate demineralizer) is used as a method to reduce the ion removal from the blowdown water of the steam generator and to reduce the injection chemical cost. Means for bypassing have been proposed (Patent Documents 1 to 3).

  However, since the blowdown water from the steam generator is hot, the existing water purification equipment cools the blowdown water at room temperature because the heat-sensitive ion effect resin is used in the condensate demineralizer. Processing. In this way, the existing water purification equipment cools the blow-down water before treatment, and the condensate demineralizer cannot sufficiently maintain the desalting function unless the cooling operation technique is used (patents). Reference 4).

  The desalting operation of blowdown water in the existing water purification equipment is intended to remove impurity ions in the blowdown water. However, among the ion species of impurities contained in the system water of the pressurized water reactor secondary system, a high concentration is a chemical such as ammonia injected as a pH adjuster.

In order to reduce the ion removal load in the condensate demineralizer, a technique for bypassing the condensate demineralizer (Patent Documents 1 to 3), an electric deionization apparatus using an ion exchange resin and an ion exchange membrane There is a technique for removing ions from blowdown water (Patent Documents 5 to 7). At that time, as a method for reducing the cost of the injected drug, a technique for recycling ammonia removed from the electric deionization apparatus has also been proposed (Patent Documents 8 and 9).
JP 2000-171585 A JP 2000-258589 A JP 2005-329314 A JP 2006-226697 A JP 2006-43580 A JP 2006-88004 A JP 2006-136846 A JP 11-47560 A JP 2007-90299 A JP 2005-144226 A JP-A-2005-214123

  In the conventional water treatment equipment applied to the secondary system of the pressurized water nuclear power plant, the impurity ions in the blowdown water as well as the pH adjuster are removed at the same time, reducing the load on the condensate demineralizer. Although it can be achieved, it is difficult to reduce the cost of the pH adjusting agent to be injected.

  Moreover, in the technique of recycling the pH adjuster removed by the electric desalting apparatus, it is necessary to separate and purify impurity ions that are removed and concentrated simultaneously with the pH adjuster, which is troublesome. In Patent Document 9 in which this is improved, in order to selectively remove only the anionic impurities, the cationic impurities are reinjected together with the pH adjuster.

  For this reason, if it is possible to selectively remove only the impurity ions from the blow-down water and establish a desalting technique that leaves a pH adjusting agent that is injected and adjusted to a higher concentration than the impurity ions by chemical injection, condensate desorption is possible. The ion removal load in the salt device can be reduced, and the drug injection cost of the pH adjuster can be reduced, which is advantageous.

  In addition, blowdown water discharged from a steam generator at a high temperature is vulnerable to high temperatures in existing demineralization technology using an ion exchange resin and a conventional electric regenerative deionization apparatus using an ion exchange resin and an ion exchange membrane. From the viewpoint of heat resistance of the ion exchange resin, in order to maintain the ion exchange function, it is required to be cooled to room temperature, and cooling equipment using a heat exchanger or the like is required.

  The present invention has been made in consideration of the above-described circumstances, and is capable of performing desalination treatment with a desalinator at a high temperature and reducing heat loss associated with cooling operation of blowdown water. An object is to provide an apparatus and a water treatment method.

  In addition, the present invention provides power system water that requires chemical injection into the secondary system of a pressurized water reactor or thermal power plant, has a small impurity ion desalting and purification load, consumes chemicals such as ammonia, and heat loss. An object of the present invention is to provide a water treatment apparatus and a water treatment method that can carry out water treatment with a small amount of water.

In order to solve the above-described problem, a water treatment apparatus according to the present invention supplies a water supply system in which a pH adjuster is injected while supplying water to a steam generator, and condensate of steam generated from the steam generator. In a water treatment device of a power plant, comprising: a circulation system that circulates to a system; and an electric desalination device that performs desalination treatment using steam generator blowdown water discharged from the steam generator as treated water,
The electric desalination apparatus comprises a desalting part formed inside the diaphragm, an electrode disposed outside the diaphragm, and a concentration part formed between the diaphragm and the electrode, and The water to be treated is desalted at a high temperature, and the impurity desalted water containing the pH adjuster discharged from the electric desalting apparatus is returned to the water supply system.

Further, the water treatment method according to the present invention includes a water supply system in which water is supplied to the steam generator and a pH adjuster is injected, and a circulation system that circulates condensed water of steam generated from the steam generator to the water supply system. In the water treatment method of a power plant, comprising: an electric desalination apparatus for desalinating the steam generator blowdown water discharged from the steam generator as treated water,
A step of subjecting the water to be treated to a high-temperature desalination treatment in a desalination section in the electric desalination apparatus; And discharging the impurity ions from the concentrating part in the electric desalting apparatus to the outside of the electric desalting apparatus.

  According to the water treatment apparatus and the water treatment method of the present invention, only the impurity ions contained in the water to be treated can be efficiently removed by subjecting the blowdown water to an electrodesalting treatment at a high temperature, while the water to be treated is treated. Can be reused while retaining most of the high-concentration infused drug contained in. Furthermore, by returning the treated water containing the injected chemical to the water supply system in a high temperature and high pressure state, the amount of chemical reinjection and the water reheating load can be reduced. Since water treatment with low consumption and heat loss can be realized, the power plant can be efficiently and appropriately operated.

Embodiments of a water treatment apparatus according to the present invention will be described with reference to the accompanying drawings.
[First Embodiment]
The water treatment apparatus according to the present invention is applied to a pressurized water nuclear reactor secondary system (PWR secondary system) of a pressurized water nuclear power plant or system water of a thermal power plant.

FIG. 1 is a configuration diagram of a water treatment apparatus according to the first embodiment of the present invention.
In a pressurized water nuclear power plant, a steam generator 1 is provided in a power generation system system, and the steam generator 1 is divided into a primary system and a secondary system of a pressurized water reactor. High-temperature and high-pressure water generated in a nuclear reactor (not shown) is sent to the steam generator 1 where it is heat-exchanged with water supplied to the steam generator 1. The steam generated in the steam generator 1 is circulated to the water supply system by the circulation system. During this time, the steam is supplied to the low-pressure turbine 4 via the high-pressure turbine 2 and the moisture separator 3, and the high-pressure turbine 2 and the low-pressure turbine. The turbine 4 is driven to generate electricity.

  A part of the steam supplied to the high-pressure turbine 2 is used as a heat source for the high-pressure feed water heater 9 as high-pressure extraction air 2-1, and then to the water supply system of the steam generator 1 via the pipe 2-2. The moisture removed from the steam by the moisture separator 3 is supplied to the water supply system of the steam generator 1 through the pipe 3-1, and the low-pressure extraction 4-1 extracted from the low-pressure turbine 4 is heated by the low-pressure supply water. After being used as a heat source for the generator 7, it is introduced into the water supply system of the steam generator 1 through the pipe 4-2. Further, the main steam discharged from the low-pressure turbine becomes water in the condenser 5 and is introduced into the water supply system of the steam generator 1 through the condensate pump 5-1. In addition, the broken-line arrow in FIG. 1 shows the flow of steam, and the solid-line arrow shows the flow of water.

  In the water supply system, the feed water supplied from the condensate pump 5-1 is purified by the condensate demineralizer 6, the water quality is adjusted by the chemical injection 20, the temperature is adjusted by the low pressure feed water heater 7, and the water is removed. After the gas and liquid are separated by the vaporizer 8, the temperature is adjusted by the high-pressure feed water heater 9, and then the water is fed to the steam generator 1.

  Further, the steam generator 1 includes a steam generator that discharges a part of the secondary water in the steam generator 1 in order to prevent corrosion of the heat transfer tubes in the steam generator 1 and deterioration in heat transfer performance. A blowdown water discharge path 10 is arranged. This blow-down water discharge path 10 extends to the condenser 5 side, and is connected to the condenser 5 or a pipe from the condenser 5 to the upstream side of the condensate demineralizer 6 (not shown).

  In the middle of the blowdown water discharge path 10, an electric desalination apparatus 11 having a bypass path 10-1 through which the blowdown water of the steam generator 1 is bypassed is provided. The electrical desalting apparatus 11 is configured as shown in a schematic diagram in FIG. 2, and desalting operation is performed at a high temperature.

Next, the configuration and function of the electrical desalting apparatus 11 will be described in detail with reference to FIG.
In FIG. 2, the electric desalting apparatus 11 has an introduction path for the water to be treated 12 and a discharge path for the impurity desalting water 13, and is arranged in a pair of equal intervals in the casing of the electric desalination apparatus 11. The diaphragm 14 and the electrode 17 for direct current application arranged on the outer side of the diaphragm are disposed, and a desalting part 15 is formed between the diaphragms, and a concentrating part 16 is formed between each diaphragm and each electrode. The treated water 12 is introduced into the desalting unit 15, and after the desalting treatment, is discharged as desalted processing water 13, while the concentrated concentrated water 16 from the concentrating unit 16 is an impurity-concentrated drainage 18 that is a concentrated impurity of removed impurities. To be discharged.

  In the first embodiment, blowdown water discharged from the steam generator 1 is introduced as treated water 12 from the steam generator blowdown water discharge path 10, and desalted treated water 13 is supplied from the steam generator 1. Sent to the water supply system.

  By the way, the electric desalination apparatus 11 provided in the steam generator blowdown water discharge path 10 performs a desalting process by applying a direct current to the electrode 17 as shown in FIG. At that time, the housing and the electrode 17 of the electric desalting apparatus 11, the housing and the diaphragm 14 of the electric desalting apparatus 11, the electrode 17 and the diaphragm 14, and the paired diaphragms 14 are electrically insulated from each other. Is desirable.

  Further, it is desirable that the liquid filled in the desalting unit 15 and the concentrating unit 16 in the electric desalting apparatus 11 is not mixed with liquids from places other than the diaphragm 16 inside the electric desalting apparatus 11. The electrode 17 is made of a material that does not easily elute the constituent components of the electrode 17 into the impurity demineralized water 13 during desalting, and a material that can be used stably in the operating temperature and current stable range of the electric desalting apparatus 11 is selected. .

  The membranes 14 that partition the desalting unit 15 and the concentration unit 16 in the electric desalting apparatus 11 are arranged to face each other in pairs, and are arranged in parallel to the electrode 17 at equal intervals. The diaphragm 14 is made of a material such as a metal, an alloy, ceramics, or a heat-resistant resin, and even if the component is high-temperature treated water that is steam generator blowdown water, the desalination treatment operation environment The materials that are difficult to elute and corrode are selected and used. The arrangement of the diaphragm 14 may be, for example, a structure in which flat plate (plate) -like diaphragms are arranged in parallel, or a structure in which concentric cylindrical (including elliptical and rectangular) diaphragms are arranged.

  The electric desalting apparatus 11 is a potential gradient in which an ionic component contained in the water 12 to be treated (steam generator blowdown water) introduced into the desalting unit 15 is applied by the electrode 17 inside the electric desalting apparatus 11. As a result, the membrane 14 permeates through the diaphragm 14 in contact with the desalting unit 15 and moves out of the desalting unit 15 by electrophoresis. As a result, the treated water ion-removed from the desalting unit 15 by the electric desalting apparatus 11 is discharged as the impurity desalted treated water 13.

  In the electric desalination apparatus 11, the ionic components that have moved to the concentration chamber 16 disposed outside the desalination section 15 and the diaphragm 14 due to the potential gradient in the desalination section 15 are extracted from the electric desalination apparatus 11 as impurity concentrated drainage 18. To be discharged.

  The system water of the pressurized water reactor secondary system (hereinafter referred to as the PWR secondary system) is injected with a chemical as a pH adjuster. For example, when ammonia is used as a chemical, PWR 2 constituting the power generation system system is used. In order to adjust the system water of the next system to about pH 9 to 10, it is necessary to adjust the ammonia concentration to about 1 to 10 mg / L.

  On the other hand, the PWR secondary system water contains impurities containing ppb order ions. That is, in the recycling mode in which impurities are removed from the steam generator blowdown water discharged from the steam generator 1 and ammonia is recycled and returned to the PWR secondary system, impurities in the ppb order are added from the ammonia water to which ammonia is added. Is required to be removed.

  Blowdown water is a high-temperature and high-pressure liquid (treated water) discharged from the steam generator 1. It has been clarified that the dissociation constant at which ammonia in water is ionized (ionized) into ammonium ions depends on the ammonia concentration, temperature, and water density. When the temperature of ammonia increases at a high temperature and a high pressure, the ionization rate (degree of ionization) decreases as shown in FIG. In the electrical desalting apparatus 11, the water to be treated 12 containing ammonia derived from the drug injection substance is desalted under a condition in which the degree of electrolysis is high due to at least one other ion species excluding ammonium ions contained in the water to be treated 12. Operated.

  FIG. 3 shows the ionization dependence of ammonia ionizing to ammonia ions in an environment with an ammonia ionization degree of 6 MPa. In the ammonia concentration range of 0.5 ppm or less (broken line), the proportion of ammonium ions present is 50% or more at room temperature, but the ionization degree decreases with increasing temperature. Similarly, even at an ammonia concentration of 1.0 ppm (solid line) and 10 ppm (single dotted line), the proportion of ammonium ions decreases as the temperature increases. Furthermore, the ionization degree decreases as the ammonia concentration increases.

  In the electric desalting apparatus 11 shown in FIG. 2, ammonia is not easily ionized because ammonia does not become ions as the steam generator blowdown water as the water to be treated 12 is processed at a higher temperature. For this reason, in the electric desalination apparatus 11, the ammonia concentration in the treated water 13 increases as the temperature is increased, and the steam generator blowdown water (treated water 12) remains as the treated water 13 at a high temperature. By returning to the PWR secondary system, ammonia and heat can be effectively reused. Since the mobility of various impurity ions increases when the treatment temperature is 100 ° C. or higher, it is desirable to set the treatment temperature in the electrodeionization apparatus 11 to 100 ° C. or higher.

  In the first embodiment, the impurity demineralized treated water 13 discharged from the electric demineralizer 11 is returned to, for example, the downstream side of the deaerator 8 of the water supply system and is returned to the steam generator 1. The treated water 13 that has been refluxed is heat-exchanged with the high-temperature high-pressure water from the nuclear reactor in the steam generator 1 to be vaporized and supplied to the high-pressure turbine 2 and the low-pressure turbine 4.

  At that time, the supply location of the impurity demineralized water 13 may be selected according to the temperature of the water to be treated supplied to the electric desalting apparatus 11. In the case of treated water, it is desirable to select a location that can be operated at high temperatures. The supply of the impurity desalted treated water 13 to the water supply system is connected by arbitrarily installing equipment such as a pump in consideration of the temperature and pressure of the supply destination.

  Moreover, when the drain system which supplies the drain water of the high pressure feed water heater which uses the turbine extraction (high pressure steam) from the high pressure turbine 2 as a heat source to the PWR secondary system is arrange | positioned, impurity demineralized treated water 13 is supplied to this drain system. May be supplied.

  In addition, ammonium ions contained in the water to be treated 12 and removed and concentrated as some ions tend to have a lower ionization degree as the ammonia concentration is higher as shown in FIG. 3, making it difficult to hold ions by an electric field. . For this reason, ammonium ions are converted into ammonia in the electric desalting apparatus 11 and diffused from the concentration unit 16, and return to the desalting unit 15.

  Therefore, in the electrical desalting apparatus 11 shown in FIG. 2, impurity ions are selectively desalted from the water to be treated 12 containing ammonia having a concentration higher than the impurity ion concentration. Is obtained as the impurity desalted treated water 13.

  From the ionization degree characteristic of ammonia shown in FIG. 3 (when desalting is performed with the electric desalination device 11 shown in FIG. 2), the electric desalting device 11 operates at a higher temperature than normal temperature, thereby producing impurity ions. As compared with the above, ammonia can selectively remain. In this sense, the material constituting the electric desalting apparatus 11 is preferably a material that can be operated at high temperatures. Further, the treatment temperature is desirably 100 ° C. or higher as described above.

  Moreover, the electric desalting apparatus 11 does not require a cooling operation during the steam generator blowdown water treatment, which is necessary in the conventional water treatment apparatus, due to the impurity ion desalting operation at a high temperature, and energy consumption for cooling. Can be reduced.

As described above, the desalting operation at a high temperature of the electric desalting apparatus 11 shown in FIG. 2 supplies the steam generator 1 without reducing the heat amount and ammonia amount of the steam generator blowdown water. Heat and ammonia recycling and impurity ion purification can be achieved efficiently.
In addition, as a form of the desalination apparatus operate | moved under high temperature / high pressure, it is not limited to what is shown in FIG. 2, The apparatus structure of various desalination apparatuses is employable (patent documents 7-9).

  Moreover, the electric desalination apparatus 11 arrange | positions several apparatuses of the same form, and switches and implements water quality purification and washing | cleaning operation in the electric desalination apparatus 11 at the time of continuous purification of the blowdown water of the steam generator 1 Alternatively, the arrangement of a plurality of units is effective in constantly purifying the PWR secondary system water.

  On the steam generator blowdown water discharge path 10, devices such as a flash tank and a heat exchanger may be arranged as necessary. For this device configuration, etc., if existing technology is used. Good. However, it is desirable to configure and operate so that fluctuations in the amount and temperature of blowdown water sent to the electric desalting apparatus 11 are reduced.

  Moreover, although the example which used ammonia as a pH adjuster was demonstrated in this 1st Embodiment, it is not limited to ammonia, Besides, ethanolamine, morpholion, etc. can be used as an injection | pouring medicine. . These agents also have a tendency to decrease the ionization characteristics at a high temperature like ammonia.

  As described above, according to the water treatment apparatus and the method thereof according to the first embodiment, only the impurity ions contained in the water to be treated can be efficiently removed by subjecting the blowdown water to the electrical desalination treatment at a high temperature. On the other hand, most of the high-concentration infusion drug contained in the water to be treated can be reused while being retained. Furthermore, by returning the treated water containing the injected chemical to the water supply system in a high temperature and high pressure state, the amount of chemical reinjection and the water reheating load can be reduced. Water treatment with low consumption and heat loss can be realized, and a nuclear power plant can be efficiently and appropriately operated.

[Second Embodiment]
A water treatment apparatus according to a second embodiment of the present invention will be described with reference to FIG. 4 that are the same as those in FIG. 1 are given the same reference numerals, and descriptions of the configurations are omitted.

  The water treatment apparatus shown in the second embodiment is applied to a PWR secondary system, and is an impurity-concentrated wastewater discharged from an electric desalination apparatus 11 disposed on a PWR secondary system steam generator blowdown water discharge path 10. 18 is supplied to the condensate demineralizer 6 which is an existing condensate purification facility.

  A heat recovery device 30 such as a heat exchange device is disposed on the supply path 18-1 as necessary. The existing technology may be used for the operation / form of the heat recovery device 30, and the form of the heat recovery device 30 is not particularly limited. The heat recovered by the heat recovery device 30 is reused in the PWR secondary system, for example, the water supply system. It is preferred that

  A plurality of condensate demineralizers 6 are arranged in parallel for maintenance of the ion exchange resin filled in the condensate demineralizer 6 and the supply path can be switched. Impurity-concentrated waste water 18 obtained by concentrating impurity ions discharged from the electric desalting apparatus 11 is introduced into a desalinator other than the condensate demineralizer that is purifying, among a plurality of condensate demineralizers 6 disposed. Then, the concentrated impurity ions are purified.

  In this way, the condensate and the impurity-concentrated waste water 18 are distinguished and purified by the condensate demineralizer 6 by recognizing the quantity and quality of the treated water to be purified by the condensate demineralizer 6. This is effective for maintaining the performance of the ion exchange resin filled in the water desalter 6 and the quality of the raw water discharged from the condensate desalter 6 and supplied to the steam generator 1. Moreover, the amount of replenishment water of PWR secondary system water can be reduced by purifying impurities in the impurity concentrated waste water 18 discharged from the electric desalting apparatus 11 and reusing water.

  According to the water treatment apparatus of the second embodiment, the concentrated impurity ions in the impurity-concentrated waste water 18 discharged from the electric desalination apparatus 11 are further purified using a condensate demineralizer, thereby providing concentrated impurities. By making it possible to maintain the quality of the water supply system by stably purifying the wastewater, most of the ammonia present at a high concentration relative to the impurity ions can be retained, and the impurities can be removed while being recycled.

[Third Embodiment]
A water treatment apparatus according to a third embodiment of the present invention will be described with reference to FIG. In FIG. 5, the same parts as those in FIG.

  The water treatment apparatus according to the third embodiment shown in FIG. 5 is a steam generator downstream of the desalinized treated water 13 of the electric desalination apparatus 11 provided in the steam generator blowdown water discharge path 1. A filtration device 31 is provided on the upstream side of the high-pressure feed water heater 9 on one feed water path.

  The electric desalting apparatus 11 removes the ionic components accumulated in the steam generator 1 in a high temperature state, while the impurity desalting water 13 subjected to the desalting process by the impurity electric desalting apparatus 11 is used in the power generation system. It returns to the steam generator 11 through the water supply system.

  In the third embodiment, in order to remove the solid component of impurities contained in the steam generator blowdown water (treated water) 12, by providing the filtration device 31, impurity ions and solid content at high temperatures are provided. Thus, the antifouling and heat transfer performance of the heat supply equipment such as the steam generator 1 and the high-pressure feed water heater 9 that are the reflux destination can be maintained soundly.

  In this 3rd Embodiment, the filter 31 is arrange | positioned in the inlet_port | entrance of the high voltage | pressure feed water heater 9 applicable to the high temperature part in a feed water system. By this structure, the solid substance contained in the blowdown water of the steam generator 1 and the feed water derived from a condenser can be simultaneously removed using the same filtration apparatus.

  The filtration device 31 may use a filtration device made of a material combined with the temperature and quality of the water to be treated supplied to the filtration device 31. In a filtration device operated at a high temperature, for example, Patent Document 10 Alternatively, the filtration device disclosed in 11 is used.

Further, a plurality of filtration devices 31 may be connected and arranged in parallel, and the filtration device and the backwashing operation process at the time of increasing the filtration differential pressure may be independently arranged in parallel. In this case, water treatment can be continuously performed by the plurality of filtration devices 31.
In addition, you may arrange | position the filtration apparatus 31 in the front | former stage side of the electrical desalination apparatus 11. FIG.

  According to the third embodiment, the solid content of impurities accumulated in the PWR secondary system steam generator 1 is removed, and at the same time, most of the ammonia present in a high concentration with respect to the impurity ions is retained and recycled. Impurities can be removed, and at the same time, the desalination operation at high temperature can realize the impurity ion desalting purification load and the water treatment with less ammonia consumption and heat loss as the chemical injection material. Can be used properly and well.

The block diagram of the water treatment apparatus which concerns on the 1st Embodiment of this invention. The schematic diagram of the desalination apparatus used with the water treatment layer which concerns on the 1st Embodiment of this invention. The relationship diagram of ammonia ionization degree and temperature. The block diagram of the water treatment apparatus which concerns on the 2nd Embodiment of this invention. The block diagram of the water treatment apparatus which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Steam generator, 2 ... High pressure turbine (steam turbine), 2-1 ... High pressure extraction, 3 ... Moisture separator, 4 ... Low pressure turbine (steam turbine), 4-1 ... Low pressure extraction, 5 ... Condenser 5-1 ... Condensate pump, 6 ... Condensate demineralizer, 7 ... Low pressure feed water heater (low pressure heater), 8 ... Deaerator, 9 ... High pressure feed water heater (high pressure heater), 10 ... Steam generator Blowdown water (discharge path), 10-1 ... Steam generator blowdown water bypass path, 11 ... Electric desalination device, 12 ... Water to be treated, 13 ... Impurity desalted water, 14 ... Separator, 15 ... Desalination , 16 ... Concentration part, 17 ... Electrode, 18 ... Impurity-concentrated waste water (discharge path), 18-1 ... Condensate demineralizer supply path for impurity-concentrated waste water, 20 ... Drug injection, 30 ... Heat recovery device, 31 ... Filtration device.

Claims (10)

A water supply system that supplies water to the steam generator and is injected with a pH adjuster, a circulation system that circulates the condensed water of the steam generated from the steam generator to the water supply system, and a high-temperature exhaust that is discharged from the steam generator. In a water treatment device of a power plant having an electrical desalination device that desalinates the steam generator blowdown water in a state as treated water,
The electric desalination apparatus comprises a desalting part formed inside the diaphragm, an electrode disposed outside the diaphragm, and a concentration part formed between the diaphragm and the electrode, and A water treatment device, wherein the water to be treated is desalted in the high temperature state, and the impurity desalted water containing the pH adjuster discharged from the electric desalting device is returned to the water supply system.   The water treatment apparatus according to claim 1, wherein the pH adjuster is ammonia.   The water treatment apparatus according to claim 1 or 2, wherein the water to be treated is desalted at 100 ° C or higher.   The water treatment apparatus according to any one of claims 1 to 3, wherein at least two of the electric desalting apparatuses are arranged in parallel.   The impurity ion concentrated water discharged from the electric demineralizer is introduced into a condensate demineralizer disposed on the downstream side of the condenser in the water supply system. The water treatment apparatus according to item.   6. The water treatment apparatus according to claim 5, wherein a plurality of the condensate demineralizers are arranged, and purification of the steam condensate of the condenser and purification of the impurity ion concentrated water are performed independently.   The water treatment apparatus according to any one of claims 1 to 6, wherein the impurity desalted treated water is returned between a low-pressure feed water heater outlet and a high-pressure feed water heater outlet.   The water treatment device according to claim 7, wherein a filter is disposed on a path for supplying the impurity desalted treated water to a steam generator.   A pressurized water nuclear power plant comprising the water treatment apparatus according to any one of claims 1 to 8 in a reactor secondary system. A water supply system that supplies water to the steam generator and is injected with a pH adjuster, a circulation system that circulates the condensed water of the steam generated from the steam generator to the water supply system, and a high-temperature exhaust that is discharged from the steam generator. In a water treatment method for a power plant having an electrical desalination device for desalinating the steam generator blowdown water in a state as treated water,
A step of subjecting the water to be treated in a high temperature to a high temperature desalting process in a desalting unit in the electric desalting apparatus, and supplying the impurity desalted water containing the pH adjuster discharged from the desalting unit A water treatment method comprising: returning to a system; and discharging impurity ions from the concentration unit in the electric desalting apparatus to the outside of the electric desalting apparatus.

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