JPH11197661A - Condensed water desalting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the lowering of the desalting capacity of the ion exchange resin in a condensed water desalting tower while ensuring the healthiness of water quality. SOLUTION: A resin keeping tank 29 is connected to a condensed water desalting tower 15 through a resin supply piping 30. A org. impurity (TOC). removing apparatus 37 is connected to the resin keeping tank 29 through a keeping water guide pipe 33. TOC eluted during keeping is adsorbed by an anion resin and an anion resin bed is provided in the lower part of the mixed bed of the anion resin and cation resin in the condensed desalting tower 15 and TOC eluted from the cation resin of the mixed bed is caught by the lower anion bed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condensate and desalination apparatus for a power plant, and more particularly to a condensate and desalination apparatus for a power plant which does not perform a chemical regeneration treatment of an ion exchange resin in a condensate desalination tower. The present invention relates to a condensate desalination apparatus configured to suppress organic impurities from a water desalination tower.

[0002]

2. Description of the Related Art Generally, in a conventional nuclear power plant, condensing and purifying water are performed in order to operate a nuclear reactor with high reliability and maintain the integrity of a primary coolant.
A general system of a conventional nuclear power plant will be described with reference to FIG.

In FIG. 5, reference numeral 1 denotes a nuclear reactor, and high-temperature, high-pressure steam generated in the reactor 1 is sent to a turbine 3 through a main steam pipe 2, where work is performed and a generator 4 is driven. The steam that has performed the work in the turbine 3 is condensed by cooling the seawater in the main condenser 5, and is condensed by a low-pressure condensate pump 6 through an air extractor 7 and a ground steam condenser 8 to a condensate desalination unit 9. Sent.

The granular cation exchange resin and anion exchange resin (having a diameter of 0.4 to
(Approximately 1.2 mm) to purify impurities such as soluble metal ions and insoluble impurities (cladding) in the condensate and chloride ions at the time of seawater leak. Thereafter, the feedwater is sent to a low-pressure feedwater heater 11 by a high-pressure condensate pump 10, and further heated and boosted through a feedwater pump 12 and a high-pressure feedwater heater 13,
The water is returned to the reactor 1 through the water supply pipe 14.

Referring to FIG. 6, the structure of the condensate desalination apparatus 9 will be described. As shown in FIG. 6, the condensate desalination tower 15 and the regeneration system 16
It consists of. In the condensate desalination tower 15, a granular ion exchange resin 17 is laminated. Then, condensate is supplied from the tower top through the condensate inlet pipe 18, and the clad and ionic impurities contained in the condensate are captured by the ion exchange resin 17. Further, the purified condensate is sent to the next device through the resin strainer 20 by the condensate outlet pipe 19.

[0006] The regeneration system 16 has an anion exchange resin regeneration tower 21 and a cation exchange resin regeneration tower 22. The anion exchange resin regeneration tower 21 is connected to the condensate desalination tower 15 by a resin transfer pipe 23.
The anion exchange resin regenerated in the anion exchange resin regeneration tower 21 is returned to the condensate and desalination tower 15 by the return pipe 24.

On the other hand, the cation exchange resin regeneration tower 22 has a return pipe
The cation exchange resin inlet pipe 25 is connected to the condensate desalination tower 15 through the cation exchange resin inlet pipe 25, and the anion exchange resin regeneration tower 21 and the return pipe 26 are connected.
Is connected to the anion exchange resin regenerating tower 21 via the. A waste liquid transfer pipe 27 is connected to the anion exchange resin regeneration tower 21,
A drain pipe 28 is connected to the cation exchange resin regeneration tower 22.

The ion exchange resin 17 in the condensate desalination tower 15
Removes the clad attached to the ion exchange resin 17 in order to increase the pressure difference pressure between the condensate inlet pipe 18 and the condensate outlet pipe 19 and increase the amount of leak of the clad to the tower outlet by the clad capture, Further, backwashing with water and air is performed to discharge the water outside the system. Further, when the ion exchange capacity is consumed by capturing the ionic impurities, chemical regeneration is performed to restore the ion exchange capacity with a chemical.

[0009]

SUMMARY OF THE INVENTION In a nuclear power plant comprising the above-described equipment, a condensate desalination apparatus in the future is operated without performing chemical regeneration of the ion exchange resin. When inspecting the inside of the desalination tower 15, a resin storage tank is separately provided instead of the anion exchange resin regeneration tower 21, and the ion exchange resin 17 in the condensate desalination tower 15 is temporarily transferred to the resin storage tank. And store it.

[0010] However, when the ion exchange resin is stored in the resin storage tank, the cation exchange resin is oxidatively degraded by dissolved oxygen contained in the storage water, and the organic impurities (hereinafter, referred to as “organic impurities”).
TOC) elutes from the cation exchange resin. When this TOC adheres to the anion exchange resin, the ion exchange capacity of the anion exchange resin is significantly reduced.

The cation exchange resin loaded in the condensate desalination tower 15 is eluted with TOC due to oxidative deterioration under the influence of oxygen and the like contained in the condensate. TOC eluted from the cation exchange resin is adsorbed on the surface of the anion exchange resin and reduces the ion exchange capacity, and when it enters the reactor, it is converted to sulfate ions by neutron irradiation and heating, and corrodes inside the furnace. And other problems.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is intended to prevent TOC eluted from a cation exchange resin from adsorbing to the anion exchange resin to prevent the performance of the anion exchange resin from deteriorating. Accordingly, it is an object of the present invention to provide a condensate desalination apparatus capable of suppressing deterioration of condensed water quality.

Further, the present invention improves the means for loading the ion exchange resin into the condensate desalination tower, and captures the TOC at the outlet of the condensate desalination tower so that condensate with a sufficiently small TOC can be obtained. And a condensate desalination apparatus.

[0014]

According to a first aspect of the present invention, a condensate desalination tower, a resin storage tank connected to the condensate desalination tower via a resin supply pipe, and a resin storage tank connected to the resin storage tank. A storage water conduit, an organic impurity removing device connected to the storage water conduit, a storage water return pipe connected between the organic impurity removing device and the resin storage tank, and a connection to the resin storage tank. And a resin storage tank outlet pipe connecting the resin storage tank and the condensate desalination tower.

According to the first aspect of the present invention, the cation exchange resin and the anion exchange resin supplied in a mixed state from the condensate demineralization tower are transferred to the resin storage tank and then stored in the lower part of the resin storage tank. Water is injected from a water injection pipe, and the mixed resin is spread inside the resin storage tank. Thereafter, water injection from the storage water injection pipe is stopped, the ion exchange resin is allowed to settle naturally, and the specific gravity difference between the cation exchange resin and the anion exchange resin is used.

Thus, both ion-exchange resins can be separated from each other. An anion-exchange resin layer is provided in an upper portion of the resin storage tank, a cation-exchange resin layer is provided in a lower portion, and an intermediate portion thereof is provided in
A mixed layer of a cation exchange resin and an anion exchange resin can be formed.

According to a second aspect of the present invention, the storage water filling the inside of the resin storage tank is guided by the storage water conduit, treated by the organic impurity removing device, and the resin storage tank is returned by the storage water return pipe. It is characterized by having a circulating system for returning to.

According to the second aspect of the present invention, the storage water inside the resin storage tank is guided from the storage water conduit under the resin storage tank,
After the treatment with the TOC removal device, the solution is returned to the resin storage tank by the storage water return pipe. Thereby, the storage water containing no TOC can always be supplied into the resin storage tank without increasing the generation of drain.

According to a third aspect of the present invention, the organic impurity removing apparatus includes a circulation pump for circulating the storage water and an organic impurity adsorption tank for removing organic impurities in the storage water. I do.

According to the third aspect of the present invention, the storage water is circulated by the circulation pump, and the TOC in the storage water is stored in the TOC adsorption tank.
Is removed. Thereby, the storage water is circulated between the resin storage tank and the TOC adsorption tank, and T eluted from the cation exchange resin.
OC can be prevented from staying inside the resin storage tank.

According to a fourth aspect of the present invention, the organic impurity removing device includes an anion exchange resin that adsorbs organic impurities.

According to the fourth aspect of the present invention, the TOC can be adsorbed by the anion exchange resin contained in the TOC adsorption tank, and the TOC in the storage water returned to the resin storage tank can be removed.

According to a fifth aspect of the present invention, the storage water return pipe comprises:
It is characterized by being located above a mixed resin layer of an anion exchange resin and a cation exchange resin located at an intermediate portion in the resin storage tank.

According to the fifth aspect of the present invention, the storage water from which the TOC has been removed is returned to the upper side of the mixed layer of the cation exchange resin and the anion exchange resin in the resin storage tank, so that the resin storage tank can be cooled. A downward flow is created to prevent TOC eluted from the cation exchange resin from adhering to the anion exchange resin at the top of the resin storage tank and to remove TOC floating near the anion exchange resin layer at the bottom of the resin storage tank. It can be moved to the ion exchange resin side.

According to a sixth aspect of the present invention, a mixed bed of a cation resin and an anion resin is loaded in a mixed-bed condensate demineralization tower comprising a granular cation exchange resin and an anion exchange resin. Characterized in that an anion exchange resin is loaded in the lower part of the.

According to the invention of claim 6, the mixed resin (C / C) supplied to the condensate desalination tower in a mixed state of cations and anions.
A ₂₎ at the bottom, provided the anion exchange resin layer (A _1).
The cation resin (C) having a higher specific gravity than (A ₂ ) is collected at the lower part of the mixed layer, but the TOC eluted from the cation is captured by the anion resin (A ₁ ) loaded on the lowermost layer. Thereby, TOC outflow from the condensate desalination apparatus can be suppressed.

[0027] The invention of claim 7 is characterized in that the anion exchange resin loaded under the mixed resin layer has a higher sedimentation rate than the cation exchange resin and the anion exchange resin of the mixed layer. .

According to the seventh aspect of the present invention, the sedimentation velocity of the lower anion exchange resin (A ₁ ) is made larger than that of the cation exchange resin and the anion exchange resin of the mixed resin layer (C / A ₂ ). When the resin is separated in the regeneration tower, an anion exchange resin layer (A ₁ ) can be formed as the lowermost layer.

The invention according to claim 8 is characterized in that the anion exchange resin loaded at the lower part of the mixed layer is not chemically regenerated with caustic soda. According to the invention of claim 8, the anion exchange resin layer (A ₁ ) loaded under the mixed resin (C / A ₂ ) has a TO content eluted from the cation exchange resin (C).
The amount of resin required to adsorb several years C is set as the amount of resin necessary for adsorption, and no chemical regeneration is required.

A ninth aspect of the present invention is characterized by having an anion exchange resin regeneration tower capable of separating, regenerating and mixing the mixed layer and a cation exchange resin regeneration tower capable of regenerating the cation exchange resin. .

According to the ninth aspect of the present invention, the anion exchange resin regeneration tower capable of separating, regenerating and mixing the mixed resin layer (C / A ₂ ) and the cation exchange resin capable of regenerating the cation exchange resin Regeneration is possible with two regeneration towers.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a condensate desalination apparatus according to the present invention will be described with reference to FIGS. In FIG. 1, reference numeral 15 denotes a condensate desalination tower in which an ion exchange resin 17 is loaded (filled). The inlet pipe 18 and the condensing outlet pipe 19 are connected, and the outlet side of the condensing outlet pipe 19 is a resin strainer.
Connected to 20. Reference numeral 29 denotes a resin storage tank, which is a resin storage tank.
The lower part of 29 is connected to the upper part of the condensate desalination tower 15 via a resin supply pipe 30.

The lower part of the resin storage tank 29 and the upper part of the condensate desalination tower 17 are connected by a resin storage tank outlet pipe 31. Also,
A resin storage tank drain pipe 32 and a storage water conduit 33 are connected to the resin storage tank 29. The storage water conduit 33 passes through a circulating pump 34 for circulating storage water and removes TOC from the TOC.
It is connected to the adsorption tank 35.

The TOC adsorption tank 35 is connected to the storage water return pipe 36 by
It is connected to the resin storage tank 29. Circulation pump 34 and TOC
A TOC removal device 37 is constituted by the adsorption tank 35. Reference numeral 38 denotes a storage water injection pipe, which is connected to the bottom of the resin storage tank 29.

Next, the operation of the present embodiment having the above configuration will be described. Ion exchange resin in condensate desalination tower 15
17 is transferred to a resin storage tank 29 via a resin supply pipe 30. Next, water is injected into the resin storage tank 29 from the storage water injection pipe 38, and the ion-exchange resin in a mixed state spontaneously settles in the injected water due to the upward flow.

At this time, as shown in FIG. 2, the cation-exchange resin and the anion-exchange resin have an anion-exchange resin layer A on the upper side and a cation-exchange resin layer on the lower side in the resin storage tank 29 due to the difference in specific gravity. A resin layer B and a mixed resin layer C in which both resins are mixed are formed near the boundary between the two.

Next, the circulation pump 34 is started, and the resin storage tank is started.
Storage water in 29 passes through storage water conduit 33, TOC adsorption tank
Lead to 35. In the TOC adsorption tank 35, the TOC in the storage water is removed, and the storage water after the removal is returned to the resin storage tank 29 through the storage water return pipe 36. The circulation of the storage water is always performed during storage of the resin, and TOC generated from the cation exchange resin is removed as needed.

After the storage of the resin is completed, the circulation pump 34
Is stopped, water is supplied from the storage water injection pipe 38 into the resin storage tank 29, the cation exchange resin and the anion exchange resin are mixed, and the condensate demineralization tower 15 is passed through the resin storage tank outlet pipe 31. Return the resin to

As described above, according to the present embodiment, the storage water conduit 33, the circulation pump 34, the TOC adsorption tank 35, and the storage water return pipe 36
Is provided, it is possible to remove TOC eluted from the cation exchange resin during storage.

Next, a second embodiment of the condensate desalination apparatus according to the present invention will be described with reference to FIGS.

In FIG. 3, reference numeral 15 denotes a condensate desalination tower,
Anion resin regeneration tower 21 into which ion exchange resin 17 is supplied, and cation resin regeneration tower storing cation resin
22 are installed. A condensate inlet pipe 18 is connected to an upper part of the condensate desalination tower 15, and a condensate outlet pipe 19 provided with a strainer 20 is connected to a lower part thereof.

The lower part of the condensate desalination tower 15 and the anion resin regeneration tower
The upper part of 21 is connected by a resin supply pipe 30.
At the bottom of the anion resin regeneration tower 21, a cation resin outlet pipe
39 is connected, and is transferred to the cation resin regeneration tower 22 via the cation resin inlet pipe 25. The chemically regenerated cation exchange resin is returned to the anion exchange resin regeneration tower 21 via the cation exchange resin return pipe 26.

The chemically formed anion exchange resin and the cation exchange resin returned from the cation exchange resin regeneration tower 22 are:
After being mixed and washed in the anion exchange resin tower 21, it is transferred to the condensate desalination tower 15 via the cation exchange resin outlet pipe 39.
The waste liquid transfer pipe 27 connected to the lower part of the anion exchange resin regeneration tower 21 and the drain pipe of the cation exchange resin regeneration tower 22 merge and are connected to waste treatment equipment.

Next, the operation of the present embodiment will be described. In FIG. 3, the condensate desalination tower 15 to the anion exchange resin regeneration tower 21
Resin that is transferred to, after backwash deployment in the column of anion exchange resin regeneration tower 21, at the time of precipitation, anion exchange resin layer in the lower layer to the difference in settling velocity as shown in FIG. 4 A ₁ ,
The layer A ₁ on the cation exchange resin C In addition, the anion exchange resin layer A ₂ is formed on its C layer.

Thereafter, the lower anion exchange resin layer A ₁ is returned to the condensate and desalination tower 15, and the cation exchange resin C remaining in the anion exchange resin regeneration tower 21 is transferred to the cation resin regeneration tower 22. and, a chemical regeneration of the anion exchange resin layer a ₂ and a cation-exchange resin C.

After the cation exchange resin C has been transferred to the anion exchange resin regeneration tower 21, final mixing and washing are performed, and the condensate desalination tower 15
Return to In the returned state, as shown in FIG. 5, an anion exchange resin layer A ₁ is formed in a lower layer, and a mixed resin layer C / A ₂ is formed in an upper layer.

[0047]

According to the present invention, TO eluted during storage
Since C does not adhere to the anion exchange resin, the performance of the resin can be prevented from deteriorating. Further, since the storage water containing the eluted TOC is not discharged to the drain, the processing amount of the waste treatment equipment can be reduced.

As described above, according to the present invention, TOC eluted from the cation exchange resin or R can be captured by the anion exchange resin formed in the lower layer under the influence of iron oxide or the like.
C can be suppressed from flowing into the reactor.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a first embodiment of a condensate desalination apparatus according to the present invention.

FIG. 2 is a longitudinal sectional view schematically showing a resin storage tank in FIG.

FIG. 3 is a system diagram showing a second embodiment of the condensate desalination apparatus according to the present invention.

FIG. 4 is a longitudinal sectional view schematically showing a resin filling state in the anion exchange resin regeneration tower in FIG.

FIG. 5 is a longitudinal sectional view schematically showing a resin filling state in the condensate demineralization tower in FIG.

FIG. 6 is a system diagram generally showing a BWR type nuclear power plant.

FIG. 7 is a system diagram generally showing the condensate desalination apparatus in FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reactor, 2 ... Main steam pipe, 3 ... Turbine, 4 ... Generator, 5 ... Main condenser, 6 ... Low-pressure condenser pump, 7 ... Air extractor, 8 ... Ground steam condenser, 9 ... Condensate desalination equipment, 10…
High-pressure condensate pump, 11: low-pressure feed water heater, 12: feed water pump, 13: high-pressure feed water heater, 14: water supply pipe, 15 ... condensate desalination tower, 16 ... regeneration system, 17 ... ion exchange resin, 18 ... Condenser inlet pipe, 19 ... Condenser outlet pipe, 20 ... Resin strainer, 21 ... Anion exchange resin regeneration tower, 22 ... Cation exchange resin regeneration tower, 23 ...
Resin transfer pipe, 24 ... Return pipe, 25 ... Cation exchange resin inlet pipe, 26 ... Return pipe, 27 ... Waste liquid transfer pipe, 28 ... Drain pipe, 29 ...
Resin storage tank, 30: Resin supply pipe, 31: Resin storage tank outlet pipe, 32: Resin storage tank drain pipe, 33: Storage water conduit, 34
… Circulation pump, 35… TOC adsorption tank, 36… storage water return pipe,
37: TOC removal device, 38: Storage water injection pipe, 39: Cation exchange resin outlet pipe.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G21C 19/307 GDB G21C 19/30 GBDD (72) Inventor Keiji Ogata 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Yokohama In business office

Claims (9)

[Claims] 1. A condensate desalination tower, a resin storage tank connected to the condensate desalination tower via a resin supply pipe, a storage water conduit connected to the resin storage tank, and a storage water conduit. A storage water return pipe connected between the organic impurity removal apparatus and the resin storage tank, a storage water injection pipe connected to the resin storage tank, and the resin storage tank And a resin storage tank outlet pipe connecting the condensate desalination tower with the condensate desalination tower. 2. A circulation system in which storage water filling the inside of the resin storage tank is guided by the storage water conduit, processed by the organic impurity removing device, and returned to the resin storage tank by the storage water return pipe. The condensate desalination apparatus according to claim 1, further comprising: 3. The organic impurity removing device according to claim 1, further comprising a circulation pump for circulating the storage water and an organic impurity adsorption tank for removing organic impurities in the storage water. Condensing desalination equipment. 4. The condensate desalination apparatus according to claim 1, wherein the organic impurity removing apparatus includes an anion exchange resin that adsorbs organic impurities. 5. The condensing water according to claim 1, wherein the storage water return pipe is located above a mixed resin layer of an anion exchange resin and a cation exchange resin in an intermediate portion of the resin storage tank. Desalination equipment. 6. A mixed bed of a cation resin and an anion resin is loaded in a mixed-bed condensate demineralization tower comprising a granular cation exchange resin and an anion exchange resin, and an anion is provided below the mixed layer. A condensate desalination apparatus characterized by being loaded with exchange resin. 7. The method according to claim 6, wherein the anion exchange resin loaded in the lower part of the mixed resin layer has a higher sedimentation rate than the cation exchange resin and the anion exchange resin of the mixed layer. Condensate desalination equipment. 8. The condensate desalination apparatus according to claim 6, wherein the anion exchange resin loaded under the mixed layer is not subjected to chemical regeneration with caustic soda. 9. The method according to claim 6, further comprising an anion exchange resin regeneration tower capable of separating, regenerating and mixing the mixed layer, and a cation exchange resin regeneration tower capable of regenerating the cation exchange resin. Condensate desalination equipment.