JP4970064B2 - Water treatment equipment - Google Patents

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 device in a secondary system of a pressurized water nuclear power plant or system water of a thermal power plant.

  In general, in a pressurized water power plant, a steam generator is divided into a primary system of a pressurized water reactor and its secondary system, and high-temperature and high-pressure water generated in the reactor of the primary reactor of the reactor is heat-exchanged with the steam generator. Steam is generated in the secondary reactor system. In a pressurized water reactor secondary system, steam generated by a steam generator is sent to a steam turbine, and this steam turbine is driven by a turbine to perform work.

  The steam expanded by driving the steam turbine is then guided to the condenser, cooled and condensed in the condenser, and becomes condensed water. This condensate is subjected to demineralization treatment for removing ions by 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, there is a chemical that performs ATV (All Volatile Treatment) treatment using ammonia as a pH adjuster and hydrazine as a deoxygenating agent. Injection material is injected.

  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 feed water from the inside of 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. Ammonia of the pH adjusting agent, which is a drug injection substance contained in blowdown water, is removed by a desalting process of a condensate demineralizer, and then a new drug injection substance is separately injected. Removing ammonia of the pH adjusting agent with a condensate demineralizer and injecting a new drug separately increases the ion removal load in the condensate demineralizer and increases the cost of drug injection.

  Bypass the condensate demineralizer (condensate demineralization tower) as a way to reduce blowdown water ions in the condensate demineralizer from the steam generator blowdown water and reduce the cost of injecting chemicals. Means are disclosed in Patent Documents 1 to 3.

  The blow-down water from the steam generator is hot, but the existing water purification equipment cools the blow-down water and treats it at room temperature because the heat-sensitive ion effect resin is used in the condensate demineralizer. ing. For this reason, in existing water purification equipment, blowdown water is cooled before treatment, and if the cooling operation technique disclosed in Patent Document 4 is not used, the condensate demineralizer has a sufficient desalting function. It cannot be maintained.

  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 ionic species of impurities contained in the system water of the pressurized water reactor secondary system, the drug injection substance present at a high concentration is ammonia injected as a pH adjuster.

  In order to reduce the ion removal load in the condensate demineralizer, the ion bypass deionizer is bypassed or the blowdown water is ionized by an electric deionizer that uses an ion exchange resin and an ion exchange membrane. There is a technology to remove.

  In the conventional technique for removing impurity ions in blowdown water, in addition to impurity ions, ammonia can be removed at the same time, so there is a great possibility of reducing the load on the condensate demineralizer, while the ammonia to be injected It is difficult to reduce costs.

Further, Patent Document 5 discloses a technology for recycling ammonia removed by an electric desalination apparatus. In this recycling technology, a technology for separating and purifying impurity ions that are concentrated simultaneously with the removed ammonia. There was a risk of increasing costs.
JP 2000-171585 A JP 2000-258589 A JP 2005-329314 A JP 2006-226697 A JP 11-47560 A

  In a conventional water treatment system applied to the secondary system of a pressurized water nuclear power plant, in addition to impurity ions in blowdown water, ammonia is also removed simultaneously, so the load on the condensate demineralizer should be reduced. However, it is difficult to reduce the cost of ammonia to be injected. Further, in the technology for recycling ammonia removed by the electric desalting apparatus, it is necessary to separate and purify impurity ions that are removed and concentrated simultaneously with ammonia, which is troublesome.

  If it is possible to selectively remove only the impurity ions from the blowdown water and establish a desalination technology that leaves ammonia adjusted to a higher concentration than the impurity ions by chemical injection, ion removal in the condensate demineralizer is possible. The load can be reduced, and the cost of injecting the ammonia drug can be reduced, which is advantageous.

  In addition, blowdown water discharged from a steam generator at a high temperature can be obtained by using existing demineralization technology that uses an ion exchange resin or conventional electric deionization equipment that uses an ion exchange resin and an ion exchange membrane. From the viewpoint of heat resistance of the exchange resin, in order to maintain the ion exchange function, it is required to be cooled to room temperature, and a cooling facility such as a large condenser is required.

  The present invention has been made in consideration of the above-described circumstances, and can perform desalting purification by a desalting apparatus at a high temperature, and can reduce heat loss associated with cooling operation of blowdown water. An object is to provide a water treatment device.

  Another object of the present invention is to reduce the impurity ion desalting and purification load in the power generation system water that requires chemical injection into the secondary system of the pressurized water reactor or the system water of the thermal power plant. It is in providing the water treatment apparatus which can implement the water treatment with few heat losses.

  In order to solve the above-described problem, a water treatment apparatus according to the present invention includes a desalinator for purifying the system water in a power generation system system, and at least one of the ionic species contained in the power system system water is a drug. In a water treatment apparatus that treats water to be treated, which is an ionic species derived from an injected substance, a direct current voltage is applied to an electrode disposed opposite to the pair of diaphragms, and the chemical injected substance contained in the treated water is derived. Desalination operation is performed on impurities other than ionic species under conditions with a low degree of ionization, and ions of water to be treated introduced between the diaphragms are removed by electrophoresis, and a desalting apparatus that passes between the diaphragms of the desalting apparatus. And a means for recycling the drug injection substance for returning the salt-treated water to the downstream side of the desalter of the power generation system.

  In the water treatment apparatus according to the present invention, the water to be treated can be recycled from the desalination apparatus using the recycling means, and the treated water having the drug injecting substance can be reused to reduce the load of the drug injecting substance and the cooling load. be able to.

  This water treatment device also reduces the reinjection amount of the chemical injection material and the supply water reheating load because the treated water having the chemical injection material is returned to the water supply system of the power generation system system at high temperature and high pressure by recycling means. can do.

  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 showing a power generation system of a pressurized water reactor secondary system 10.

  In the pressurized water nuclear power plant, a steam generator 11 as an intermediate heat exchanger is provided in the power generation system system, and the steam generator 11 divides the pressurized water reactor primary system and its secondary system 10. In the primary system of the pressurized water reactor, high-temperature and high-pressure water generated in a nuclear reactor (not shown) is sent to the steam generator 11 where it is heat-exchanged with the feed water supplied to the steam generator 11. The steam generated by the steam generator 11 is supplied to the high-pressure turbine 13 through the (main) steam system 12 constituting the pressurized water reactor secondary system (PWR secondary system) 10, and the high-pressure turbine 13 is driven by the turbine. I do the work. The PWR secondary system 10 constitutes a power generation system system. The power generation system system includes a (main) steam system 12 and a condensate water supply system 19.

  The steam that has driven the high-pressure turbine 13 is then sent to the moisture separator 14 where the moisture is removed and dried steam. This dry steam is sent to the low-pressure turbine 15 to drive the turbine and work. The steam that has worked in the low-pressure turbine 15 expands and is guided to the condenser 16, cooled by the condenser 16, and condensed to condensate. The condensate cooled by the condenser 16 is sent to a condensate water supply system 19 of the power generation system by a condensate pump 18.

  The condensate water supply system 19 is provided in a condensate demineralizer 21 such as a condensate demineralizer, and is purified by an ion exchange resin in the condensate demineralizer 20 to be desalted. Further, the condensate demineralizer 20 is provided with a demineralizer bypass circuit 21 that protects the demineralizer 20 in case of an emergency such as seawater leak or an accident. The condensate demineralized by the condensate demineralizer 20 is then sent to a low-pressure feed water heater (low-pressure heater) 23 having a single-stage or multi-stage structure by a condensate booster pump 22 and subjected to a heating action. The low-pressure feed water heater 23 is supplied with turbine bleed air a from the low-pressure turbine 15, and condensate is heated using the turbine bleed air a as a heating source.

  On the other hand, the drain water cooled by exchanging heat with the condensate in the low-pressure feed water heater 23 is supplied to the condensate in the condensate water supply system 19 by the drain pump 24, and the condensate from the ascites demineralizer 20 is mixed. .

  Further, the condensate heated by the low pressure feed water heater 23 of the condensate feed water system 19 is sent to the deaerator 27, degassed by the deaerator 27, and then passed through the feed water pump 28 to the high pressure feed water heater. (High pressure heater) 29. The high pressure feed water heater 29 exchanges heat with the turbine bleed air b from the high pressure turbine 14 and receives a heating action. The feed water whose temperature has risen due to the heating action becomes high temperature and is supplied to the steam generator 11. The feed water whose temperature has been raised by the high-pressure feed pump 29 is heat-exchanged with the high-temperature and high-pressure water from the pressurized water reactor by the steam generator 11. Steam generated by the steam generator 11 by this heat exchange is supplied to the steam turbines 13 and 15 through the (main) steam system 12 and driven by the turbine.

  On the other hand, the turbine bleed air b heated by the high-pressure feed water heater 29 exchanges heat with the feed water to become drain water, and is sent to the deaerator 27 by the drain pump 30. In this deaerator 27, it mixes with the condensate sent from the low-pressure feed water heater 23, and is made to merge. For example, three condensate pumps 19, condensate booster pumps 22 and water supply pumps 28 are provided in parallel, and one is used as a spare machine.

  Further, the steam generator 11 has a steam generator blowdown water discharge path for discharging a part of the water supply of the steam generator 11 in order to prevent corrosion of the heat transfer pipe in the steam generator 11 and deterioration of heat transfer performance. 33 is arranged. This blow-down water discharge path 33 extends to the condenser 16 side, and is connected to a condensate water supply system 19 from the condenser 16 to a required location upstream of the condensate demineralizer 20.

  In the middle of the blow-down water discharge path 33, an electric desalination apparatus 34 and a heat recovery apparatus 35 are sequentially provided as necessary. The electric desalting apparatus 34 is configured as schematically shown in FIG. 2 and is configured to perform a desalting operation at a high temperature. The electric desalting apparatus 34 is provided with a bypass circuit 36 for bypassing the steam generator blowdown water, and a normally open bypass valve 37 is provided in the bypass circuit 36 when the electric desalting apparatus 34 fails or starts up. , Provided to open.

  As shown in FIG. 2, the (electrical) electric desalting apparatus 34 includes a box-shaped main body casing 40 as a desalter housing, a pair of electrodes 41 to which direct current is applied in the main body casing 40, and these electrodes. 41, a pair of diaphragms 43 arranged in parallel with each other, a desalting part 44 of the water c to be treated constituted between these diaphragms 43, and steam generator blowdown water to be treated in the desalting part 44 An introduction path 35 for supplying water c, a discharge path 46 for impurity-desalted water d discharged from the desalting section 44, a concentration section 47 disposed in the chamber between the diaphragm 43 and the electrode, and the concentration section 47, and a discharge path 48 for the impurity-concentrated waste water e discharged from 47. The concentration section 47 and the discharge path 48 constitute a discharge means for concentrated waste water. The discharge path 48 is connected to the upstream side of the condensate demineralizer 20, for example, the inlet side of the condensate pump 18.

  The discharge path 48 for the impurity-concentrated drainage e is connected to a blowdown water discharge path 33 that extends to the condensate water supply system 19 that constitutes the power generation system, and the discharge path 46 for the impurity desalted treated water d is the condensate water supply system 19. For example, it is connected to the inlet side of the water supply pump 28. The low-pressure feed water heater 23 is returned at a pressure substantially equal to the feed water in the feed water system (condensate feed water system 19) from the outlet side to the inlet side of the steam generator 11 and mixed. The discharge path 46 of the impurity desalted treated water d constitutes a means for recycling ammonia that is a drug injection substance.

  Further, a drain pipe 50 extends from the moisture separator 14 of the pressurized water reactor secondary system 10, and the drain pipe 50 is connected to a deaerator of a condensate water supply system 19, for example, a power generation system system, via a drain pump 51. 27 A high-temperature liquid component connected to the downstream side and separated by the deaerator 27 is supplied to the feed water and mixed.

  By the way, the electric desalination apparatus 34 provided in the steam generator blowdown water discharge path 33 performs a desalting process by applying a direct current to the electrode 41 as shown in FIG. At that time, it is desirable that the body casing 40 and the electrode 41, the body casing 40 and the diaphragm 43, the electrode 41 and the diaphragm 43, and the paired diaphragms 43 are electrically insulated from each other.

  In addition, it is desirable that the liquid filled in the desalting unit 44 and the concentration unit 47 in the main body casing 40 does not mix with liquid from a place other than the diaphragm 43 inside the electric desalting apparatus 34. The electrode 41 is made of a material that does not easily elute the constituent components of the electrode 41 into the impurity desalted water d during desalting, and a material that can be used stably in the operating temperature and current stable range of the electric desalting apparatus 34 is selected. .

  The diaphragm 43 that partitions the desalinating part (desalting region) 44 and the concentrating part (concentrating region) 47 in the main body casing 40 is disposed to face each other in a pair and in parallel with the electrode 41. The diaphragm 43 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 blow-down water, The materials to be eluted, corroded and analyzed are selected and used. Various arrangements of the diaphragm 43 are conceivable, and are configured in a parallel arrangement of a flat plate (plate) shape or a parallel arrangement of a concentric cylinder shape (an elliptic cylinder shape or a square tube shape).

  In the electrical desalting apparatus 34, a liquid to be treated (steam generator blowdown water) c is introduced into the desalting unit 44. The ionic component contained in the introduced water c to be treated permeates through the diaphragm 43 in contact with the desalting unit 44 due to the potential gradient applied by the electrode 41 inside the electric desalting device 34, and the outside of the desalting unit 44. Move by electrophoresis. As a result, the high-temperature treated water ion-removed by the electrical desalting apparatus 34 is discharged from the desalting unit 44 as the impurity desalted treated water d.

  The ion component moved to the concentration chamber 47 disposed outside the desalting unit 44 and the diaphragm 43 by the electric potential gradient in the desalting unit 44 in the electric desalination unit 34 is discharged from the discharge path 48 as an impurity concentrated drainage. 34 is discharged to the outside and sent to existing water purification equipment such as the condensate demineralizer 20 for purification.

  In the pressurized water reactor secondary system (hereinafter referred to as PWR secondary system) 10, ammonia as a pH adjuster derived from the chemical injection material is added to the water c to be treated. It is required to remove impurities in the order of ppb from ammonia-rich water to which ammonia is added. In order to adjust the PWR secondary system 10 constituting the power generation system to pH 9.2 to 9.8, it is necessary to adjust the ammonia concentration to about 1 to 10 mg / L.

  On the other hand, the steam generator blowdown water (blow water) is a high-temperature and high-pressure liquid (treated water) discharged from the steam generator 11. It has been clarified that under high temperature and high pressure, the dissociation constant of ionization (ionization) of ammonia into ammonium ions depends on 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. The water to be treated, which is an ionic species derived from ammonia as the drug injection substance, is desalted under a condition of low electrolysis by at least one other ionic species contained in the water to be treated.

  FIG. 3 shows the ionization dependence of ionizing to ammonia ions under 6 MPa. In the ammonia concentration range, the proportion of ammonium ions present is 50% or more at normal temperature, but as 0.5 ppm is indicated by a dotted line f, 1.0 ppm is indicated by a solid line g, and 10 ppm is indicated by a chain line h, the higher the temperature becomes. The proportion of ammonium ions is reduced. In the electric desalting apparatus 34 shown in FIG. 2, the steam generator blowdown water (the water c to be treated) is at a high temperature, so that ammonia is difficult to remove. This tendency becomes more remarkable as the temperature increases.

  In addition, ammonium ions from which the water to be treated c is partially removed and concentrated as shown in FIG. 3 tend to have a lower ionization degree as the ammonia concentration is higher, making it difficult to hold ions by an electric field. For this reason, ammonium ions are converted into ammonia in the electric desalting apparatus 34 and diffused from the concentrating unit 47 and returned to the desalting unit 44.

  Therefore, in the electric desalting apparatus 34 shown in FIG. 2, the treated water c containing impurity ions and ammonia having a higher concentration than these ions is desalted, and the treated water in which ammonia remains in the desalting unit 44. Is obtained as impurity desalted treated water d.

  From the ionization degree characteristics of ammonia shown in FIG. 3 (when desalting is performed with the electric desalination device 34 shown in FIG. 2), the electric desalting device 34 is operated 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 34 is preferably a material that can be operated at a high temperature.

  Moreover, the electric desalting apparatus 34 is necessary in the conventional water treatment apparatus by the impurity ion desalination operation at a high temperature, and the cooling operation at the time of the steam generator blow-down water treatment becomes unnecessary, and the cooling operation to the room temperature is performed. The amount can be reduced. The form of the desalting apparatus operated under high temperature and high pressure is not limited to that shown in FIG. 2, and various desalting apparatuses such as JP-A 2006-43580, JP-A 2006-88004, and JP-A 2006 are disclosed. The apparatus configuration disclosed in Japanese Patent No. -134646 can be employed.

  The heat supplied to the steam generator 11 without greatly reducing the amount of heat of the steam generator blowdown water and the amount of ammonia by the desalting operation at a high temperature of the electric desalting apparatus 34 shown in FIG.・ Ammonia recycling and impurity ion purification can be obtained.

  The steam generator blow water discharged from the steam generator 11 is sent to the electric desalting apparatus 34 via the steam generator blow down water discharge path 33.

  On the path of the steam generator blowdown water discharge path 33, components such as a flash tank and a heat exchanger may be arranged as necessary, and the existing technology may be used for the device configuration and the like. . However, it is desirable to configure and operate so that fluctuations in the amount and temperature of blowdown water sent to the electrical desalting apparatus 34 are reduced.

  In the electric desalting apparatus 34, high-temperature steam generator blowdown water is used as water to be treated c for removing ionic components at a high temperature. Therefore, instead of the electric desalting apparatus 34, Japanese Patent Application Laid-Open No. 2006-43580 or Desalination apparatuses such as those disclosed in JP-A-2006-88004 and JP-A-2006-136844 may be applied.

  In the electric desalting apparatus 34, impurities are removed by the desalting portion 44 in the main body casing 40, and the steam generator blowdown water retains a large amount of ammonia as the amount of heat of the treated water c and pH adjusting agent. It is discharged from the drainage path 46 as treated water d.

  The impurity demineralized treated water d is returned to the steam generator 11 by the recycling means constituting the drainage path 46 downstream of the condensate water supply system 19, for example, downstream of the deaerator 27. The refluxed treated water d is heat-exchanged with the high-temperature high-pressure water from the nuclear reactor in the steam generator 11 to be vaporized, and is supplied to the steam turbines 13 and 15 through the (main) steam system 12.

  At this time, the supply location of the impurity demineralized treated water d may be selected according to the temperature of the water to be treated supplied to the electric desalting apparatus 34. 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 demineralized treated water d is at a lower pressure than the treated water, for example, the outlet of the low pressure heater 23, the deaerator 27 disposed between the low pressure heater 23 and the high pressure heater pump 28, or the inlet of the high pressure heater pump 28. Connected.

  Moreover, when the drain system which supplies the drain water of the high pressure heater which uses the turbine extraction (high pressure steam) from the high pressure turbine 13 as a heat source to the PWR secondary system 10 is arranged, the impurity desalted treated water d is supplied to this drain system. You may supply.

  Further, the impurity ions removed by the electric desalting apparatus 34 are supplied from the electric desalting apparatus 34 to the existing desalting and purification equipment of steam generator blowdown water as the impurity concentrated waste water e. On the supply path 48, a heat recovery device 35 such as a heat exchange device is disposed as necessary. As for the operation / form of the heat recovery device 35, an existing technology may be used, and the form thereof is not particularly limited.

  Furthermore, on the steam generator blowdown water discharge path 33, a bypass circuit 36 that bypasses the electric desalination apparatus 34 as a spare system can be installed in the same manner as the existing steam generator blowdown water discharge path 33. In this case, pre-treatment is performed so that the steam generator blow-down water bypassing the electric desalting apparatus 34 can be appropriately handled in the existing desalting purification system, for example, the condensate desalinator 20 of the condensate water supply system 19. (Temperature operation etc.) and desalination treatment capacity are desirable.

  According to the water treatment apparatus shown in the first embodiment, most of the ammonia present at a high concentration with respect to the impurity ions is retained, and the impurities are removed from the treated water c while being recycled. By the desalting treatment in, water treatment with less impurity ion desalting and purification load, ammonia consumption, and heat loss can be realized, and the nuclear power plant can be efficiently and appropriately operated.

[Second Embodiment]
FIG. 4 is a configuration diagram schematically showing a second embodiment of the water treatment apparatus according to the present invention.

  In the description of the water treatment apparatus of this embodiment, the same configurations and operations as those of the first embodiment of the water treatment apparatus shown in FIGS. To do.

  The water treatment apparatus shown in the second embodiment is applied to the PWR secondary system 10A, and a plurality of electric demineralizers 34A, 34B are arranged in parallel in the steam generator blowdown water discharge path 33 of the PWR secondary system 10A. And is applied to the water treatment of the steam generator blowdown water, and the configuration of the other desalting apparatus is not substantially different, and thus detailed description thereof is omitted.

  A plurality of the electrical desalting apparatuses 34A and 34B are arranged in parallel in the steam generator blowdown water discharge path 33, and at least one of the electrical desalting apparatuses 34A and 34B is used for ion removal, and the treated water c By adopting a configuration in which the introduction paths 45A and 45B can be switched, the other desalting apparatus can be placed in a standby state. By using the other desalting apparatus when performing the washing operation of the desalting apparatus, ion removal of the water to be treated c can be continuously performed.

  When performing the washing operation of the electric desalting apparatuses 34A and 34B without performing the desalting operation, the polarities of the pair of electrodes 41 and 41 arranged in the desalting apparatus that performs the washing operation are set to the same values as in the desalting operation. The washing operation is carried out by applying a voltage directly opposite to the polarity.

  By applying direct current (voltage) so that the polarities of the electrodes 41 and 41 are reversed during the desalting operation of the electrical desalting apparatuses 34A and 34B, even if deposits or the like are generated on the electrodes 41 and 41 during the desalting. In addition, it is possible to perform elution cleaning of the precipitates, and to maintain the desalting performance and the desalting function in a healthy state for a long time.

  The plurality of electric desalting apparatuses 34A and 34B ensure a pretreatment such as a temperature operation for the washing operation and a desalting treatment capacity so that the washing operation and the desalting operation can be individually operated in parallel. It is desirable to keep it.

  According to the water treatment apparatus of the second embodiment, the operation of the electric desalting apparatuses 34A and 34B can be stably and elastically performed, so that most of ammonia present at a high concentration with respect to impurity ions can be retained. The impurities can be removed while being recycled. Even in the case of desalting treatment at high temperature, it is possible to realize water treatment with less impurity ion desalting and purification load, ammonia consumption, and less heat loss, and the nuclear plant can be efficiently and appropriately operated.

[Third Embodiment]
FIG. 5 is a simplified configuration diagram of the third embodiment of the water treatment apparatus according to the present invention.

  In describing the water treatment apparatus of the third embodiment, the same components and functions as those of the first embodiment are denoted by the same reference numerals, and redundant description is omitted or simplified.

  The third embodiment of the water treatment device shown in FIG. 5 is substantially different in the configuration in which the filtration device 53 is provided on the upstream side of the impurity electric desalination device 34 provided in the steam generator blowdown water discharge path 33. Since other configurations are not different, the description is omitted.

  The impurity electrical desalting apparatus 34 can remove the ionic components accumulated in the steam generator 11 in a high-temperature state, while the impurity desalinized water d desalted by the electrical desalting apparatus 34 for impurities is It is recirculated to the steam generator 11 through the condensate water supply system 19 of the power generation system through the recycling means.

  In the third embodiment of the water treatment device, a filtration device 53 is disposed in front of the electric desalting device 34 in order to remove solid components of impurities contained in the steam generator blowdown water (treated water) c. An example was given. The filtration device 53 may use a filtration device made of a material combined with the temperature and water quality of the water to be treated c supplied to the filtration device 53. In a filtration device operated at a high temperature, for example, The filtration device disclosed in JP-A-2005-144226 and JP-A-2005-214123 is used.

  A plurality of filtration devices 53 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 53, which is preferable. The filtration device 53 may be disposed on the rear side of the impurity electrodeionization device 34.

  According to the third embodiment of the water treatment apparatus shown in FIG. 5, simultaneously with the removal of the solid content of impurities accumulated in the steam generator 11 of the PWR secondary system 10 </ b> B, the ammonia present in a high concentration with respect to the impurity ions is removed. Retaining impurities and removing impurities while retaining the majority, and at the same time, by desalting operation at high temperature, realizes water treatment with less impurity ion desalting purification load and consumption of ammonia as chemical injection material and less heat loss It is possible to operate the nuclear power plant efficiently and appropriately.

[Fourth Embodiment]
FIG. 6 is a block diagram schematically showing a fourth embodiment of the water treatment apparatus according to the present invention.

  In describing the fourth embodiment of the water treatment apparatus, the same configurations and operations as those of the water treatment apparatus shown in the first embodiment are denoted by the same reference numerals, and redundant description is omitted or simplified.

  The water treatment apparatus shown in the fourth embodiment is applied to the PWR secondary system 10C, and an impurity electric desalination apparatus 34 is provided in the steam generator blowdown water discharge path 33 of the PWR secondary system 10C. While the electric desalination apparatus 34 performs the desalination process with the steam generator blowdown water (water to be treated) c treated at a high temperature, the impurity desalinized water demineralized by the electric desalination apparatus 34. A flow rate controller 54 as a flow rate control mechanism and a water quality monitor 55 as a water quality monitor mechanism are disposed in the middle of the discharge path 46 of d. The other configuration is not different from the configuration of the first embodiment of the water treatment device, and thus the description thereof is omitted.

  The water treatment apparatus shown in FIG. 6 has a flow rate controller 54 and a water quality monitor 55 installed in the middle of a discharge path 46 that constitutes a recycling means for the impurity desalination treated water d discharged from the impurity electric desalination apparatus 34. While the flow rate controller 54 measures and prepares the flow rate of the impurity desalted treated water d, the water quality monitor 55 measures the ammonia concentration, impurity ion concentration, and hydrogen ion concentration contained in the impurity desalted treated water d.

  The flow rate controller 54 includes a device that measures the flow rate of the liquid flowing through the discharge path 46 of the impurity demineralized treated water d and a device that adjusts the flow rate. What is necessary is just to select the existing flow controller 54 in connection with another environment, and the form in particular is not limited. The water quality monitor 55 is a device that measures the ammonia concentration, impurity ion concentration, and hydrogen ion concentration contained in the impurity demineralized treated water d. The water quality monitor 55 may be installed online in the discharge path 46 of the impurity demineralized treated water d, or may be a sampling measurement method. The existing water quality monitor 55 may be used in consideration of the use conditions of the equipment for which the water quality monitor 55 is selected, the temperature pressure of the discharge path 46, the water quality, and the like. It is also more desirable to install a flow rate controller and a water quality monitor on the discharge path 46 of the impurity concentrated waste water e.

  According to the fourth embodiment of the water treatment apparatus shown in FIG. 6, it is possible to grasp the flow rate control of the impurity demineralized treated water d discharged from the impurity electric desalination apparatus 34 and the ammonia content. The amount of ammonia that needs to be injected can be ascertained at any time. For this reason, it is possible to appropriately control the pH water quality of the pressurized water reactor secondary system 10C. Simultaneously with the removal of the solid content of the impurities accumulated in the steam generator 11, most of the ammonia as the drug injection substance present at a high concentration with respect to the impurity ions can be retained. Impurity solids can be removed while recycling the treated water by means of recycling the desalted treated water d, and most of the ammonia can be retained. Injection can be suppressed, impurity ion desalting and purification load, ammonia treatment and water treatment with less heat loss can be implemented, and a nuclear power plant can be operated efficiently and appropriately.

  In the first to fourth embodiments of the present invention, an example in which the water treatment device is applied to PWR secondary water treatment has been shown. However, this water treatment device is a thermal power generation that requires chemical injection into a steam system. It can be applied to the system water of the plant.

The block diagram which shows the example which applied 1st Embodiment of the water treatment apparatus which concerns on this invention to the pressurized water reactor secondary system. The schematic diagram of the desalination apparatus used for 1st Embodiment of the water treatment apparatus of this invention. The graph which shows the relationship between ammonia ionization degree at the time of operating the said desalination apparatus under 6 Mpa, and temperature. The block diagram which shows the example which applied 2nd Embodiment of the water treatment apparatus which concerns on this invention to the pressurized water reactor secondary system. The block diagram which shows the example which applied 3rd Embodiment of the water treatment apparatus which concerns on this invention to the pressurized water reactor secondary system. The block diagram which shows the example which applied 4th Embodiment of the water treatment apparatus which concerns on this invention to the pressurized water reactor secondary system.

Explanation of symbols

10,10A Pressurized water reactor secondary system (PWR secondary system)
11 Steam generator 12 Steam system (main steam system)
13 High-pressure turbine (steam turbine)
14 Moisture separator 15 Low pressure turbine (steam turbine)
16 Condenser 18 Condensate Pump 19 Condensate Water Supply System 20 Condensate Demineralizer 21 Condenser Bypass Circuit 22 Condensate Booster Pump 23 Low Pressure Feed Water Heater (Low Pressure Heater)
24 Drain pump 27 Deaerator 28 Water supply pump 29 High-pressure feed water heater (high-pressure heater)
30 Drain pump 33 Steam generator blowdown water discharge path 34, 34A, 34B Desalination equipment (impurity desalination equipment)
35 Heat recovery device 36 Bypass circuit 37 Bypass valve 40 Main body casing (demineralizer housing)
41 Electrode 43 Diaphragm 44 Desalination part 45, 45A, 45B of treated water Introduction path 46 Discharge path 47 of impurity desalted treated water Concentration part 48 Discharge path (supply path) of impurity concentrated waste water
50 Drain piping 51 Drain pump 53 Filtration device 54 Flow controller (Flow control mechanism)
55 Water quality monitor (Water quality monitoring mechanism)

Claims (10)

The power generation system system is equipped with a demineralizer that purifies the system water,
In a water treatment apparatus for treating water to be treated, wherein at least one of the ionic species contained in the power generation system water is an ionic species derived from a drug injection substance,
A direct current voltage is applied to the electrodes arranged opposite to the pair of diaphragms, and a desalting operation is performed on impurities other than ionic species derived from the drug injection substance contained in the water to be treated under a condition of low ionization degree. A desalting apparatus that removes ions of water to be treated by electrophoresis;
A water treatment apparatus comprising: a recirculation unit for the chemical injection substance that returns demineralized water passing between the diaphragms of the demineralizer to the downstream side of the demineralizer of the power generation system. The water treatment apparatus according to claim 1, wherein the recycling means is a medicine injection material ammonia. The water treatment apparatus according to claim 1, wherein the power generation system water is secondary water of a pressurized water nuclear power plant. The desalination apparatus is an electric desalination apparatus having means for discharging concentrated waste water between electrodes disposed on both sides in the main body casing and a pair of diaphragms disposed between the electrodes.
The water treatment apparatus according to claim 1, further comprising a discharge path for introducing the concentrated wastewater to the upstream side of the desalter of the power generation system. The water treatment apparatus according to claim 1, wherein the desalinator provided in the power generation system system is a condensate demineralizer. The water treatment apparatus according to claim 1, wherein at least two of the desalting apparatuses are arranged in parallel. The water treatment device according to claim 1, wherein a filter is disposed on at least one of an introduction route through which the water to be treated is introduced into the desalination device and a route through which the desalted treatment water is returned to the power generation system. The water treatment apparatus according to claim 1 or 4, wherein a flow rate control mechanism is provided in at least one of a path of treated water discharged from the desalination apparatus and a means for discharging concentrated waste water. The water treatment apparatus according to claim 8, wherein a mechanism for monitoring water quality is provided in at least one of a discharge path of the treated water discharged from the desalination apparatus and the concentrated waste water. 2. The steam generator according to claim 1, further comprising a steam generator in the power generation system system, at least one desalting device provided in a blowdown water discharge path from the steam generator, and a bypass circuit bypassing the desalting device. Water treatment equipment.

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