Treatment system for blow-down water of steam generator of nuclear power plant

Abstract

The invention provides a treatment system for blow-down water of a steam generator of a nuclear power plant. The treatment system comprises a drain pipeline, a desalting unit, a resin regeneration unit and a resin conveying unit. The drainage pipeline is communicated with a blow-off pipeline of the steam generator, and the desalting unit is connected with the drainage pipeline and comprises resin for desalting sewage flowing through the drainage pipeline; the resin conveying mechanism is communicated with the desalting unit and the resin regeneration unit; after being saturated, the resin enters the resin regeneration unit through the resin conveying mechanism for regeneration, and returns to the desalting unit through the resin conveying unit for reuse after regeneration. According to the treatment system, the technical problem that in the sewage treatment process of an existing steam generator, the purchase, storage and treatment cost of resin is high can be solved, cross contamination with other systems is avoided, two (multiple) desalting units share one resin regeneration unit, the manufacturing cost of the desalting system can be reduced, and the energy consumption of the desalting system is reduced. And centralized management and control and centralized collection and discharge of wastewater are facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear power plant sewage discharge, and in particular to a treatment system for sewage discharged from a steam generator of a nuclear power plant. Background Art

[0002] The steam generator wastewater treatment system of a nuclear power plant provides water chemical conditions for the continuous discharge of steam generators under different operating conditions to maintain the normal operation of the steam generators, collects, filters, and desalinates the steam generator wastewater, and then discharges the treated wastewater into the condensate extraction system for reuse.

[0003] The main impurities in steam generator wastewater are Na - , Cl - 、SO4 2- Plasma, in traditional steam generator wastewater treatment systems, ion exchange technology is generally used to purify wastewater. After the resin is saturated, the resin is directly replaced and no longer reused, which will lead to high costs for purchasing, storing and disposing of the resin. Summary of the invention

[0004] In view of the above shortcomings of the prior art, the present invention provides a nuclear power plant steam generator wastewater treatment system to improve the technical problem of high resin purchase, storage and disposal costs in the existing steam generator wastewater treatment process.

[0005] To achieve the above-mentioned purpose and other related purposes, the present invention provides a treatment system for wastewater discharged from a steam generator of a nuclear power plant, the treatment system comprising: a drainage pipeline, a desalination unit, a resin regeneration unit and a resin conveying unit, wherein the drainage pipeline is connected to the steam generator sewage pipeline; the desalination unit is connected to the drainage pipeline, the desalination unit comprises a resin for desalting wastewater flowing through the drainage pipeline; the resin regeneration unit is arranged outside the drainage pipeline to regenerate the resin in the desalination unit; the resin conveying unit is connected to the desalination unit and the resin regeneration unit; wherein, after the resin is saturated, it enters the resin regeneration unit through the resin conveying unit for regeneration, and after regeneration, it returns to the desalination unit through the resin conveying unit for reuse.

[0006] In one example of the treatment system of the present invention, the drainage pipeline includes multiple drainage branches connected in parallel, and a desalination unit is respectively arranged on each drainage branch to desalinate the sewage flowing through each drainage branch; the multiple desalination units are connected to the resin regeneration unit through the resin delivery unit to realize that the multiple desalination units share one resin regeneration unit.

[0007] In an example of the treatment system of the present invention, the drainage pipeline includes a first drainage branch and a second drainage branch, and the resin regeneration unit is arranged between the first drainage branch and the second drainage branch.

[0008] In an example of the processing system of the present invention, the resin delivery unit includes a first delivery pipeline and a second delivery pipeline connected in parallel, a first desalination unit is arranged in the first drainage branch, and a second desalination unit is arranged in the second drainage branch; the first delivery pipeline is connected to the first desalination unit, and the second delivery pipeline is connected to the second desalination unit; the resin in the first desalination unit and the resin in the second desalination unit respectively enter the resin regeneration unit alternately through the first delivery pipeline and the second delivery pipeline for regeneration.

[0009] In an example of the treatment system of the present invention, the desalination unit includes a desalination mixed bed containing cation resin and anion resin, and the sewage in the drainage pipeline flows through the desalination mixed bed and then is discharged.

[0010] In an example of the treatment system of the present invention, the desalination unit includes a desalination cation bed containing cation resin and a desalination mixed bed containing cation resin and anion resin. The sewage in the drainage pipeline flows through the desalination cation bed and the desalination mixed bed in sequence and is then discharged.

[0011] In an example of the treatment system of the present invention, the resin regeneration unit is configured to treat one of the resins of the desalination cation bed and the resins of the desalination mixed bed at a time.

[0012] In an example of the treatment system of the present invention, the resin regeneration unit includes a desalination cation bed regeneration unit and a desalination mixed bed regeneration unit. The desalination cation bed regeneration unit is used to regenerate the saturated cation resin of the desalination cation bed, and the desalination mixed bed regeneration unit is used to regenerate the saturated cation resin and saturated anion resin of the desalination mixed bed.

[0013] In an example of the treatment system of the present invention, the desalination mixed bed regeneration unit includes a mixed bed resin separation tower, an anion resin regeneration tower and a cation resin regeneration tower, the mixed bed resin separation tower includes a cation resin output end and an anion resin output end, the cation resin output end is connected to the cation resin regeneration tower, the anion resin output end is connected to the anion resin regeneration tower, and the anion resin regeneration tower is also connected to the cation resin regeneration tower.

[0014] In an example of the treatment system of the present invention, the desalination units on all drainage branches share a desalination cation bed regeneration unit and a desalination mixed bed regeneration unit.

[0015] In an example of the treatment system of the present invention, the resin regeneration unit also includes an acid-base system for providing acid and alkali required in the resin regeneration process, and the desalination cation bed regeneration unit and the desalination mixed bed regeneration unit share the same acid-base system.

[0016] In an example of the treatment system of the present invention, the resin regeneration unit also includes a wastewater collection and discharge unit required for resin regeneration, and the desalination cation bed regeneration unit and the desalination mixed bed regeneration unit share a wastewater collection and discharge unit.

[0017] The nuclear power plant steam generator wastewater treatment system provided by the present invention is provided with a resin regeneration unit and a resin conveying unit. After the resin is saturated, it can enter the resin regeneration unit through the resin conveying unit for regeneration, and after regeneration, it can return to the desalination unit through the resin conveying unit for reuse. This arrangement can realize multiple regeneration of the resin in the desalination unit, and the regenerated resin can be reused, so the frequency of resin replacement can be reduced, and the cost of resin purchase, storage, and disposal can be reduced. At the same time, since the regenerated resin will be returned to the desalination unit for continued use, the labor required for replacing the resin can be reduced, and the labor cost can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A structural block diagram of a processing system in one embodiment of the present invention;

[0020] Figure 2 It is a structural block diagram of a desalination unit in one embodiment of the present invention;

[0021] Figure 3 This is a structural block diagram of a resin regeneration unit in one embodiment of the present invention;

[0022] Figure 4 FIG. 4 is another structural block diagram of a processing system in an embodiment of the present invention.

[0023] Component number description

[0024] 10. Steam generator sewage pipeline; 20. Drainage pipeline; 21. First drainage branch; 22. Second drainage branch; 30. Desalination unit; 301. First desalination unit; 302. Second desalination unit; 303. Resin containing chamber; 31. Desalination mixed bed; 32. Desalination cationic bed; 40. Resin regeneration unit; 401. Resin regeneration chamber; 41. Desalination cationic bed regeneration unit; 42. Desalination mixed bed regeneration unit; 421. Mixed bed resin separation tower; 4211. Cation resin output end; 4212. Anion resin output end; 422. Anion resin regeneration tower; 423. Cation resin regeneration tower; 43. Acid-base system; 44. Sewage collection and discharge unit; 50. Condensate extraction system; 60. Resin conveying mechanism; 601. Resin conveying pipeline; 61. First conveying pipeline; 62. Second conveying pipeline. DETAILED DESCRIPTION

[0025] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the features in the following embodiments and the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturers.

[0026] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention, and any methods, equipment and materials of the prior art similar or equivalent to the methods, equipment and materials described in the embodiments of the present invention can also be used to implement the present invention.

[0027] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" etc. used in this specification are only for the convenience of description and are not intended to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be regarded as the scope of implementation of the present invention.

[0028] See also Figures 1 to 4 The nuclear power plant steam generator wastewater treatment system provided by the present invention is provided with a resin regeneration unit 40 and a resin conveying unit 60. After the resin is saturated, it can enter the resin regeneration unit 40 through the resin conveying unit 60 for regeneration, and after regeneration, it can return to the desalination unit 30 through the resin conveying unit 60 for reuse. Therefore, the resin in the desalination unit 30 can be regenerated, and then the resin can be reused, reducing the frequency of resin replacement and reducing the cost of resin purchase, storage and disposal.

[0029] See also Figure 1 The treatment system of the present invention includes a drainage pipeline 20, a desalination unit 30, a resin regeneration unit 40 and a resin delivery unit 60.

[0030] The water inlet of the drainage pipeline 20 is connected to the drainage outlet of the steam generator sewage pipeline 10, and the water outlet of the drainage pipeline 20 is connected to the condensate extraction system 50. When the condensate extraction system 50 is in operation, the sewage in the steam generator sewage pipeline 10 enters the drainage pipeline 20, and enters the condensate extraction system 50 after being desalted by the resin in the desalination unit 30 on the drainage pipeline 20 for recycling. The drainage pipeline 20 can be a single pipeline, or two (or more) pipelines connected in parallel between the steam generator sewage pipeline 10 and the condensate extraction system 50. The specific number of drainage pipelines 20 is determined by the number of steam generator sewage pipelines 10, as long as one drainage pipeline 20 is connected to the drainage outlet of each steam generator sewage pipeline 10.

[0031] The desalination unit 30 is arranged in the drainage pipeline 20, and a resin is arranged between the water inlet of the desalination unit 30 and the water outlet of the desalination unit 30. The water inlet of the desalination unit 30 is connected to the drainage outlet of the steam generator sewage pipeline 10, and the water outlet of the desalination unit 30 is connected to the condensate extraction system 50, so that when the sewage flows through the drainage pipeline 20, the resin in the desalination unit 30 can desalinate the sewage. The resin in the desalination unit 30 can be an anion resin and / or a cation resin that can perform ion exchange on anions and / or cations in the sewage. It should be noted that the resin in the desalination unit 30 will reach a saturated state after a period of use, resulting in a weakening of the ion exchange capacity of the resin, so it is necessary to replace the new resin or regenerate the resin to restore the desalination capacity of the desalination unit 30.

[0032] The resin regeneration unit 40 is disposed outside the drainage pipe 20 to regenerate the resin in the demineralization unit 30. The specific regeneration structure of the resin regeneration unit 40 is not limited, for example, the resin regeneration unit 40 can be any regeneration structure capable of regenerating the saturated resin in the demineralization unit 30, such as a positive resin regeneration tower, a negative resin regeneration tower, etc.

[0033] See also Figures 1 to 4 The resin delivery unit 60 is connected to the demineralization unit 30 and the resin regeneration unit 40. The resin regeneration unit 40 includes a resin regeneration chamber 401, the demineralization unit 30 includes a resin containing chamber 303, and the resin delivery unit 60 includes a resin delivery pipe 601, which connects the resin regeneration chamber 401 and the resin containing chamber 303. There are many ways to deliver the resin in the resin delivery pipe 601. For example, the resin delivery unit 60 may be provided with compressed air and a pump, and the resin is transported in the resin delivery pipe 601 by air / hydraulic force, so as to realize the transportation of the resin between the demineralization unit 30 and the resin regeneration unit 40.

[0034] After the resin is saturated, it enters the resin regeneration unit 40 through the resin delivery unit 60 for regeneration, and after regeneration, it returns to the desalination unit 30 for reuse through the resin delivery unit 60. A water quality detection sensor, such as a conductivity meter, can be set on the outlet side of the desalination unit 30 to monitor the treatment quality of the sewage on the outlet side of the desalination unit 30 in real time. When the water quality sensor detects that the water quality on the outlet side of the desalination unit 30 does not meet the standard, it can be inferred that the resin in the desalination unit 30 is in a saturated state and needs to be regenerated. It should be noted that the number of times the resin can be regenerated is not limited, as long as the resin can meet the sewage desalination requirements after regeneration.

[0035] After the sewage discharged from the drain outlet of the steam generator sewage pipe 10 flows into the water inlet of the drainage pipe 20, when passing through the desalination unit 30, the resin in the desalination unit 30 will desalinate the sewage, and the desalinated water flow will be discharged from the outlet of the drainage pipe 20 and enter the condensate extraction system 50 for recycling. When the resin in the desalination unit 30 reaches saturation, the resin will enter the resin regeneration unit 40 through the resin delivery pipe 601 on the resin delivery unit 60 for regeneration treatment, and the regenerated resin will return to the desalination unit 30 through the resin delivery pipe 601 for repeated normal use. It should be noted that when the saturated resin leaves the desalination unit 30, the resin containing chamber 303 in the desalination unit 30 remains empty until the resin returns to the resin containing chamber 303 in the desalination unit 30 after the regeneration treatment. By setting the resin regeneration unit 40 and the resin delivery unit 60, when the resin in the desalination unit 30 reaches saturation, the saturated resin can enter the resin regeneration unit 40 through the resin delivery unit 60 for regeneration treatment, and return to the desalination unit 30 for continued use after regeneration, thereby realizing multiple regeneration and reuse of the resin, thereby reducing the frequency of resin replacement in the desalination unit 30 and reducing the cost of resin purchase, storage, and disposal. At the same time, since the desalination unit 30 does not need to introduce new resin during the resin regeneration process, the regenerated resin can be put into use again, thereby reducing the labor required for replacing the resin and reducing labor costs.

[0036] In an example of the treatment system of the present invention, the drainage pipeline 20 includes a plurality of drainage branches connected in parallel, each drainage branch corresponds to a steam generator sewage pipeline 10, that is, the drainage outlet of each steam generator sewage pipeline 10 is connected to the condensate extraction system 50 through a drainage branch. A desalination unit 30 is respectively arranged on each drainage branch to desalinate the sewage flowing through each drainage branch. The specifications and models of each desalination unit 30 may be the same or different, and are determined by the actual sewage treatment capacity requirements of each drainage branch during production and use. Multiple desalination units 30 share a resin regeneration unit 40 for resin regeneration, that is, a resin regeneration unit 40 is arranged between the steam generator sewage pipeline 10 and the condensate extraction system 50, and when the resin in all desalination units 30 arranged on all drainage branches reaches a saturated state during use, they will enter the resin regeneration unit 40 through the resin delivery unit 60 for resin regeneration. In this way, multiple steam generator sewage pipes 10 can share a set of resin regeneration units 40, thereby reducing equipment investment and operating costs. At the same time, because the number of resin regeneration units 40 is reduced, the overall installation space of the sewage treatment system can be smaller, which is convenient for installation and use in places with limited space.

[0037] Optionally, see Figure 1 In an example of the treatment system of the present invention, the drainage pipeline 20 includes a first drainage branch 21 and a second drainage branch 22. The first drainage branch 21 connects a steam generator wastewater pipeline 10 and a condensate extraction system 50, and the second drainage branch 22 connects another steam generator wastewater pipeline 10 and a condensate extraction system 50. The first drainage branch 21 is provided with a first desalination unit 301, and the second drainage branch 22 is provided with a second desalination unit 302. The resin regeneration unit 40 is provided between the first drainage branch 21 and the second drainage branch 22. The resin regeneration unit 40 is provided between the first drainage branch 21 and the second drainage branch 22, which means that the resin regeneration unit 40 is provided in the middle area surrounded by the first drainage branch 21 and the second drainage branch 22. Specifically, as Figure 1 As shown in , the first drainage branch 21 is located above the resin regeneration unit 40, the second drainage branch 22 is located below the resin regeneration unit 40, the resin regeneration unit 40 is arranged between the first drainage branch 21 and the second drainage branch 22, and the distances between the resin regeneration unit 40 and the first drainage branch 21 and the second drainage branch 22 are equal or approximately equal. In other embodiments, the first drainage branch 21 may be located to the left of the resin regeneration unit 40, the second drainage branch 22 may be located to the right of the resin regeneration unit 40, and so on. By arranging the resin regeneration unit 40 between the first drainage branch 21 and the second drainage branch 22, the overall structure of the treatment system for the wastewater discharged from the steam generator of a nuclear power plant can be made more centralized, further reducing the overall footprint of the equipment.

[0038] See also Figures 1 to 4 In an example of the treatment system of the present invention, the resin delivery pipeline 601 includes a first delivery pipeline 61 and a second delivery pipeline 62 connected in parallel. The first delivery pipeline 61 is connected to the resin containing chamber 303 of the first desalination unit 301, so that the resin in the first desalination unit 301 enters and exits the resin regeneration chamber 401 and the resin containing chamber 303 through the first delivery pipeline 61. The second delivery pipeline 62 is connected to the resin containing chamber 303 of the second desalination unit 302, so that the resin in the second desalination unit 302 enters and exits the resin regeneration chamber 401 and the resin containing chamber 303 through the second delivery pipeline 62. The resin in the first desalination unit 301 and the resin in the second desalination unit 302 enter the resin regeneration chamber 401 alternately through the first delivery pipeline 61 and the second delivery pipeline 62 for regeneration. It should be noted that, here, alternately entering the resin regeneration chamber 401 for regeneration means that only one of the first delivery pipeline 61 and the second delivery pipeline 62 performs the resin delivery operation at a time, thereby ensuring that the resin regeneration unit 40 only regenerates one of the resin in the first desalination unit 301 and the resin in the second desalination unit 302 at a time. For example, the resin in the first desalination unit 301 may enter the resin regeneration unit 40 through the first delivery pipeline 61 for regeneration, and when the resin regeneration is completed, the resin in the first desalination unit 301 is returned to the resin containing chamber 303 of the first desalination unit 301 through the first delivery pipeline 61. Next, the resin in the second desalination unit 302 enters the resin regeneration unit 40 through the second delivery pipeline 62 for regeneration. After the resin regeneration is completed, the resin in the second desalination unit 302 returns to the resin containing chamber 303 of the second desalination unit 302 through the second delivery pipeline 62. In this way, the resin in the first desalination unit 301 and the resin in the second desalination unit 302 alternately enter the resin regeneration unit 40 for regeneration. In this way, the resin in the first desalination unit 301 and the resin in the second desalination unit 302 can be alternately regenerated in the resin regeneration unit 40, thereby reducing the number of resin regeneration units set inside the resin regeneration unit 40.

[0039] In an example of the treatment system of the present invention, the desalination unit 30 includes a desalination mixed bed 31 containing a cation resin and an anion resin, and the desalination mixed bed 31 is arranged in a resin accommodating chamber 303, and the sewage in the drainage pipeline 20 flows through the desalination mixed bed 31 and is discharged. The bed structure shape of the desalination mixed bed 31 is not limited, for example, it can be a cylindrical, rectangular structure or a layered structure. The installation method of the desalination mixed bed 31 in the resin accommodating chamber 303 can be a detachable connection, such as a detachable connection with bolts, or a non-detachable connection, such as a welding fixed connection. The parameters such as the setting volume and setting layer height of the cation resin and the anion resin in the desalination mixed bed 31 can be the same or different, and the specific needs are determined according to the content of cations and anions in the sewage to be treated. The cation resin and the anion resin are arranged in the resin accommodating chamber 303 according to the set layered structure or other structural forms. The specific setting structure of the cation resin and the anion resin in the desalination mixed bed 31 can refer to the relevant description in the existing desalination mixed bed 31, and will not be repeated here. By setting up the desalination mixed bed 31, the anions and cations in the sewage can be removed simultaneously by the cation resin and the anion resin in the desalination mixed bed 31, thereby achieving the desalination of the sewage in the steam generator sewage pipeline 10. At the same time, since the cation resin and the anion resin are integrated together, the floor space of the desalination unit 30 can be reduced, which is convenient for the installation layout of the equipment.

[0040] See also Figure 2 and Figure 4In an example of the treatment system of the present invention, the desalination unit 30 includes a desalination cation bed 32 containing a cation resin and a desalination mixed bed 31 containing a cation resin and an anion resin. The water inlet of the desalination cation bed 32 is connected to the drain outlet of the steam generator sewage pipe 10, the water outlet of the desalination cation bed 32 is connected to the water inlet of the desalination mixed bed 31, and the water outlet of the desalination mixed bed 31 is connected to the water outlet of the drainage pipe 20, so that the sewage entering the drainage pipe 20 from the drain outlet of the steam generator sewage pipe 10 flows through the desalination cation bed 32 and the desalination mixed bed 31 in sequence, and then enters the condensate extraction system 50. Similarly, the shape of the bed structure of the desalination cation bed 32 is not limited, for example, it can be a cylindrical, rectangular structure or a layered structure. The installation method of the desalination cation bed 32 in the resin accommodating chamber 303 can be a detachable connection, such as a detachable connection with bolts, or a non-detachable connection, such as a fixed connection with welding. By setting a desalination cation bed 32 at the front end of the desalination mixed bed 31, when the sewage flows through the front end desalination cation bed 32, the cationic resin on the desalination cation bed 32 will first remove the cationic impurities in the sewage, such as calcium, magnesium, etc., and when the water discharged from the desalination cation bed 32 then enters the desalination mixed bed 31, the anions in the desalination mixed bed 31 will remove the remaining anionic impurities in the sewage, and at the same time, the cations in the desalination mixed bed 31 can further remove the residual cationic impurities in the sewage. In this way, the cationic and anionic impurities in the sewage can be treated in stages, and the effluent water quality can be improved. At the same time, when the cationic bed fails or needs maintenance, the mixed bed can continue to play a desalination role, thereby increasing the reliability of the system.

[0041] See also Figure 2 and Figure 4In an example of the treatment system of the present invention, the resin regeneration unit 40 is configured to process one of the resins on the desalination cation bed 32 and the resins on the desalination mixed bed 31 each time. After the cation resin of the desalination cation bed 32 is saturated, it will enter the resin regeneration unit 40 through the resin delivery pipe 601 for regeneration. After the cation resin and anion resin of the desalination mixed bed 31 are saturated, they will also enter the resin regeneration unit 40 through the resin delivery pipe 601 for regeneration. The resin regeneration unit 40 is configured to process one of the resins on the desalination cation bed 32 and the resins on the desalination mixed bed 31 each time, which means that each time the resin regeneration unit 40 can only be one of the resins on the desalination cation bed 32 and the resins on the desalination mixed bed 31, that is, each time one of the resins on the desalination cation bed 32 and the resins on the desalination mixed bed 31 enters the resin regeneration unit 40 for regeneration, the other continues to maintain the desalination working state on the drainage pipe 20. For example, when the resin on the desalination cation bed 32 is saturated and enters the resin regeneration unit 40 for regeneration treatment, the desalination mixed bed 31 continues to be used to maintain the desalination capacity of the sewage. In this way, during the regeneration of the cation resin, it is ensured that there is still resin in the drainage pipe 20 for sewage desalination, so that the sewage treatment can be carried out uninterruptedly during the resin regeneration process, ensuring the treatment efficiency of the sewage. It should be noted that, due to the large number of cationic impurities in the sewage, the desalination cation bed 32 arranged at the front end of the desalination mixed bed 31 is most likely to reach a saturated state, and the frequency of its regeneration treatment is higher than that of the desalination mixed bed 31.

[0042] See also Figure 3 and Figure 4 In an example of the treatment system of the present invention, the resin regeneration unit 40 includes a desalting cation bed regeneration unit 41 and a desalting mixed bed regeneration unit 42. The desalting cation bed regeneration unit 41 is used to regenerate the saturated cation resin of the desalting cation bed 32, and the desalting mixed bed regeneration unit 42 is used to regenerate the saturated cation resin and the saturated anion resin of the desalting mixed bed 31. The setting position between the desalting cation bed regeneration unit 41 and the desalting mixed bed regeneration unit 42 is not limited, and the internal specific structure of the desalting cation bed regeneration unit 41 and the desalting mixed bed regeneration unit 42 is also not limited. Under the condition of meeting the requirements for the regeneration of the saturated cation resin and the saturated anion resin, the desalting cation bed regeneration unit 41 and the desalting mixed bed regeneration unit 42 can be a conventional resin regeneration tower structure used for the existing desalting bed regeneration.

[0043] Specifically, the desalination cation bed regeneration unit 41 may include a cation resin regeneration tank, a cation resin inlet, a liquid inlet pipe and a liquid outlet pipe arranged on the cation resin reaction tank, and the cation resin regeneration tank contains a cation resin regeneration liquid. The saturated cation resin on the desalination cation bed 32 enters the cation resin regeneration tank through the resin delivery pipeline 601, and the cation resin regeneration liquid enters the cation resin regeneration tank through the liquid inlet pipe, and infiltrates the saturated cation resin, a displacement reaction occurs, and the cation resin is regenerated.

[0044] It should be noted that saturated cationic resins usually contain adsorbed cations, such as sodium ions (Na + ), magnesium ion (Mg 2+ ) etc. In order to restore the exchange capacity of the cation resin, it is usually necessary to use a strong acid for regeneration, the most common being hydrochloric acid (HCl). The chemical process of regeneration of saturated cation resin can be expressed by the following chemical equation: For example, when regenerating with hydrochloric acid (HCl): R-Na + +HCl→RH + +NaCl. In the above equation: R- represents the fixed negative charge site on the resin; Na + represents the cation adsorbed on the resin, which can be any cation, such as Na + or Mg 2+ etc.; HCl is the acid used to regenerate the resin. RH + Represents the regenerated resin, where H + It is an exchangeable ion. NaCl is a byproduct generated during the regeneration process. It will be carried away with the cation resin regeneration liquid and discharged into the sewage regeneration wastewater pool. The regeneration process replaces the adsorbed cations on the saturated cation resin with H + To restore the exchange capacity of the resin so that it can adsorb cations in the water again. The regenerated cation resin can be reused to remove cationic impurities in sewage.

[0045] Since the desalination mixed bed 31 includes both cation resin and anion resin mixed with each other, when regeneration is required, the cation resin must be separated from the anion resin and then each must be regenerated separately using a corresponding regenerative acidic or alkaline chemical. Figure 3 and Figure 4 In an example of the treatment system of the present invention, the desalination mixed bed regeneration unit 42 includes a mixed bed resin separation tower 421, an anion resin regeneration tower 422 and a cation resin regeneration tower 423, and the mixed bed resin separation tower 421 is used to separate the cation resin and the anion resin of the desalination mixed bed 31. The output end of the mixed bed resin separation tower 421 includes a cation resin output end 4211 and an anion resin output end 4212, and the cation resin output end 4211 is connected to the input end of the cation resin regeneration tower 423, and the anion resin output end 4212 is connected to the input end of the anion resin regeneration tower 422. The output end of the anion resin regeneration tower 422 is also connected to the input end of the cation resin regeneration tower 423 to achieve the mixing of the regenerated cation resin and the regenerated anion resin at the position of the cation resin regeneration tower 423. The cation resin regeneration tower 423 is used to regenerate the separated cation resin to restore its ion exchange capacity. The anion resin regeneration tower 422 is used to regenerate the separated anion resin to restore its ion exchange capacity.

[0046] The specific structure of the mixed bed resin separation tower 421 is not limited. In the present embodiment, the mixed bed resin separation tower 421 includes conveying the mixed resin formed by the cation resin and the anion resin to a dedicated separation chamber. In the separation chamber, the anion resin with a lower density is raised to the top of the cation resin by the upward backwash of the water flow, thereby forming a cation resin layer and anion resin layer separated from each other, and realizing the separation of the cation resin and the anion resin. In other embodiments, the mixed bed resin separation tower 421 can also be other structures that can realize the phase separation of the cation resin and the anion resin. It should be noted that the separation method of the cation resin and the anion resin in the mixed bed resin separation tower 421 is a conventional structure in the current technology. The mixed bed resin separation tower 421 in the present embodiment can refer to the current related structure introduction, which will not be repeated here.

[0047] In this embodiment, the structure of the cation resin regeneration tower 423 is similar to that of the above-mentioned desalination cation bed regeneration unit 41, and both use cation resin regeneration liquid for chemical reaction, and the chemical reaction process is the same, which will not be repeated here. The structure of the anion resin regeneration tower 422 can also be similar to that of the desalination cation bed regeneration unit 41, but an anion resin regeneration liquid is used, and the saturated anion resin is fully contacted with the anion resin regeneration liquid, a chemical reaction occurs, and anion resin regeneration is achieved.

[0048] It should be noted that saturated anion resins usually contain adsorbed anions, such as chloride ions (Cl - ), sulfate ion (SO4 2- ) etc. In order to restore the exchange capacity of the anion resin, a regeneration process is required, which usually involves the use of a strong base, the most common of which is sodium hydroxide (NaOH). The chemical process of regenerating anion resin can be represented by the following chemical equation: For example, regeneration using sodium hydroxide (NaOH): R + Cl - +NaOH→R + OH - +NaCl, in the above equation: R + Represents the fixed positive charge sites on the resin. - Represents the anion adsorbed on the anion resin, which can be any anion, such as Cl - etc. NaOH is the base used to regenerate the resin. + OH - Represents the regenerated resin, where OH - It is an exchangeable hydroxide ion. NaCl is a byproduct generated during the regeneration process and will be taken away with the regeneration liquid. The regeneration process replaces the adsorbed anions on the anion resin with OH - To restore the exchange capacity of the resin so that it can adsorb anionic impurities in the sewage again. The regenerated anionic resin can be reused to remove anionic impurities in sewage.

[0049] By setting the desalination cation bed regeneration unit 41 and the desalination mixed bed regeneration unit 42 in the resin regeneration unit 40, each regeneration unit can be specifically used for regeneration of different types of saturated resins, so that the exchange capacity of the resin can be restored more effectively. At the same time, the working state and regeneration frequency of each regeneration unit can be flexibly adjusted according to actual needs to better match the replacement frequency of the resin of the desalination cation bed 32 and the resin of the desalination mixed bed 31.

[0050] When the resin on the desalination mixed bed 31 is saturated, the saturated resin will enter the resin regeneration unit 40. Inside the resin regeneration unit 40, the saturated resin first enters the mixed bed resin separation tower 421. After separation, the saturated cation resin is input from the cation resin output end 4211 to the cation resin regeneration tower 423, and the saturated anion resin is input from the anion resin output end 4212 to the anion resin regeneration tower 422. Then the regenerated anion resin enters the cation resin regeneration tower 423, and after mixing with the regenerated cation resin, it is directly transported back to the desalination mixed bed 31 and put into normal use. In this way, the mixed bed resin separation tower 421, the anion resin regeneration tower 422 and the cation resin regeneration tower 423 are connected to each other to form a complete regeneration treatment system, which can meet the regeneration requirements of the resin on the desalination mixed bed 31. At the same time, the design of the mixed bed resin separation tower 421 also ensures that the cation resin and the anion resin can be effectively separated, avoids cross contamination, and improves the regeneration effect.

[0051] In an example of the treatment system of the present invention, the desalination units 30 on all drainage branches share a desalination cationic bed regeneration unit 41 and a desalination mixed bed regeneration unit 42. Only one desalination cationic bed regeneration unit 41 and one desalination mixed bed regeneration unit 42 are provided in the resin regeneration unit 40. When there are multiple drainage branches, there are also multiple desalination units 30 correspondingly provided. After saturation, the resin on the desalination cationic bed 32 in each desalination unit 30 is regenerated by the above-mentioned desalination cationic bed regeneration unit 41, and the resin on the desalination mixed bed 31 in each desalination unit 30 is regenerated by the above-mentioned desalination mixed bed regeneration unit 42. It should be noted that during the regeneration process, the resins of multiple desalination cationic beds 32 alternately enter the desalination cationic bed regeneration unit 41 for regeneration, and the resins in multiple desalination mixed beds 31 alternately enter the desalination mixed bed regeneration unit 42 for regeneration. Such an arrangement further improves the utilization rate of the desalting cationic bed regeneration unit 41 and the desalting mixed bed regeneration unit 42, reduces the number of the desalting cationic bed regeneration unit 41 and the desalting mixed bed regeneration unit 42 inside the resin regeneration equipment, and thus can reduce the equipment investment cost and the floor space occupied by the equipment installation.

[0052] See also Figure 3 and Figure 4In an example of the treatment system of the present invention, the resin regeneration unit 40 also includes an acid-base system 43 for providing the acid and alkali required in the resin regeneration process. Acid (e.g., hydrochloric acid) and alkali (e.g., sodium hydroxide) are required in the resin regeneration process, and the acid-base system 43 generally includes conventional configuration components in the existing acid-base system 43, such as a chemical storage area, a dissolving tank, a metering system, a pipeline transportation system, and a control system. In this embodiment, the desalination cation bed regeneration unit 41 and the desalination mixed bed regeneration unit 42 share an acid-base system 43. Specifically, the acid-base system 43 may include a first output end and a second output end, and the first output end and the second output end are respectively connected to the desalination cation bed regeneration unit 41 and the desalination mixed bed regeneration unit 42 to realize the setting that the desalination cation bed regeneration unit 41 and the desalination mixed bed regeneration unit 42 share an acid-base system 43. By making the desalination cation bed regeneration unit 41 and the desalination mixed bed regeneration unit 42 share an acid-base system 43, the repeated configuration of the acid-base system 43 can be reduced, and the investment cost of the equipment and the installation area occupied by the equipment can be reduced. At the same time, sharing an acid-base system 43 makes it easier to centrally monitor the concentration, flow rate and other parameters of the monitoring chemicals in the acid-base system 43, and perform maintenance and adjustments in a timely manner.

[0053] Since wastewater containing chemicals (such as acid, alkali) and other impurities is generated during the resin regeneration process, if the wastewater is discharged directly without treatment, it will cause environmental pollution. Figure 3 and Figure 4 , the resin regeneration unit 40 also includes a sewage collection and discharge unit 44, and the desalination cationic bed regeneration unit 41 and the desalination mixed bed regeneration unit 42 share a sewage collection and discharge unit 44. The sewage collection and discharge unit 44 includes two sewage collection ends, and the two sewage collection ends are respectively connected to the drainage end of the desalination cationic bed regeneration unit 41 and the drainage end of the desalination mixed bed regeneration unit 42, so that the desalination cationic bed regeneration unit 41 and the desalination mixed bed regeneration unit 42 share a sewage collection and discharge unit 44. The sewage entering the sewage collection and discharge unit 44 will be uniformly discharged after being neutralized and treated to meet certain discharge standards. The setting of sharing a sewage collection and discharge unit 44 can realize the centralized treatment of wastewater in the resin regeneration unit 40, reduce the number of sewage collection and discharge units 44, and thus reduce the floor space of the equipment, optimize the equipment installation space, and also reduce the equipment investment and construction costs.

[0054] The treatment system for wastewater discharged from a steam generator of a nuclear power plant provided by the present invention is provided with a resin regeneration unit, and the resin in the desalination unit is configured to enter the resin regeneration unit for regeneration after saturation, and return to the desalination unit for reuse after regeneration, so that multiple regeneration of the resin in the desalination unit group can be achieved, and the regenerated resin can be reused, so the frequency of resin replacement can be reduced, and the cost of purchasing, storing and disposing of the resin can be reduced. At the same time, since the regenerated resin will be returned to the desalination unit for continued use, the labor required for replacing the resin can be reduced, and the labor cost can be reduced. Therefore, the present invention effectively overcomes some practical problems in the prior art and has a high utilization value and use significance. The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the relevant technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A nuclear power plant steam generator wastewater treatment system, characterized in that: include: Drain pipe, connected to the steam generator sewage pipe; a desalination unit connected to the drainage pipeline, the desalination unit comprising a resin for desalting sewage flowing through the drainage pipeline; a resin regeneration unit, disposed outside the drainage pipeline, to regenerate the resin in the desalination unit; a resin delivery unit, the resin delivery unit being connected to the desalination unit and the resin regeneration unit; After the resin is saturated, it enters the resin regeneration unit through the resin delivery unit for regeneration, and after regeneration, it returns to the desalination unit through the resin delivery unit for reuse.

2. The processing system according to claim 1, wherein: The drainage pipeline includes multiple drainage branches connected in parallel, and each drainage branch is respectively provided with a desalination unit to desalinate the sewage flowing through each drainage branch; multiple desalination units are connected to the resin regeneration unit through the resin conveying mechanism to achieve multiple desalination units sharing one resin regeneration unit.

3. The processing system according to claim 2, characterized in that The drainage pipeline includes a first drainage branch and a second drainage branch, and the resin regeneration unit is arranged between the first drainage branch and the second drainage branch.

4. The processing system according to claim 3, characterized in that The resin conveying mechanism includes a first conveying pipeline and a second conveying pipeline connected in parallel with each other, a first desalination unit is provided in the first drainage branch, and a second desalination unit is provided in the second drainage branch; the first conveying pipeline is connected to the first desalination unit, and the second conveying pipeline is connected to the second desalination unit; the resin in the first desalination unit and the resin in the second desalination unit respectively enter the resin regeneration unit alternately through the first conveying pipeline and the second conveying pipeline for regeneration.

5. The processing system according to claim 1, wherein: The desalination unit comprises a desalination mixed bed containing cation resin and anion resin, and the sewage in the drainage pipeline flows through the desalination mixed bed and is then discharged.

6. The processing system according to claim 1, wherein: The desalination unit comprises a desalination cation bed containing cation resin and a desalination mixed bed containing cation resin and anion resin. The sewage in the drainage pipeline flows through the desalination cation bed and the desalination mixed bed in sequence and is then discharged.

7. The processing system according to claim 6, characterized in that The resin regeneration unit is configured to treat one of the resin of the desalination cation bed and the resin of the desalination mixed bed at a time.

8. The processing system according to claim 6, characterized in that The resin regeneration unit includes a desalination cation bed regeneration unit and a desalination mixed bed regeneration unit. The desalination cation bed regeneration unit is used to regenerate the saturated cation resin of the desalination cation bed, and the desalination mixed bed regeneration unit is used to regenerate the saturated cation resin and saturated anion resin of the desalination mixed bed.

9. The processing system according to claim 8, characterized in that The desalination mixed bed regeneration unit includes a mixed bed resin separation tower, an anion resin regeneration tower and a cation resin regeneration tower. The mixed bed resin separation tower includes a cation resin output end and an anion resin output end. The cation resin output end is connected to the cation resin regeneration tower, the anion resin output end is connected to the anion resin regeneration tower, and the anion resin regeneration tower is also connected to the cation resin regeneration tower.

10. The processing system according to any one of claims 1 to 9, characterized in that The desalination units on all the drainage branches share one desalination cation bed regeneration unit and one desalination mixed bed regeneration unit.

11. The processing system according to claim 10, characterized in that The resin regeneration unit also includes an acid-base system for providing acid and alkali required in the resin regeneration process. The desalination cation bed regeneration unit and the desalination mixed bed regeneration unit share the same acid-base system.

12. The processing system according to claim 10, wherein: The resin regeneration unit further comprises a sewage collection and discharge unit required for the resin regeneration, and the desalination cation bed regeneration unit and the desalination mixed bed regeneration unit share the sewage collection and discharge unit.

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