Method for controlling pH value of boron alkaline water in high-temperature and high-pressure irradiation test loop

Abstract

The invention discloses a method for controlling the pH value of boron alkaline water in a high-temperature and high-pressure irradiation test loop, the pH value of the boron alkaline water is adjusted to a preset pH value range by utilizing the relationship between the boron element concentration and the alkali concentration, the pH control operation of the loop water is simple and convenient, large-scale complicated special water chemical control facilities such as a chemical volume system are not needed, and the cost is low. Less radioactive waste liquid is generated, the control precision is high, and the pH value of low-boron alkaline water in a high-temperature and high-pressure irradiation test loop can be safely and efficiently ensured to be within a limit range.

Description

Technical Field

[0001] The invention relates to the field of nuclear technology, and in particular to a method for controlling the pH value of boric alkaline water in a high-temperature and high-pressure irradiation test loop. Background Art

[0002] The high-temperature and high-pressure irradiation test loop can simulate the real water chemical conditions of the first loop of a pressurized water reactor. The temperature of the water in the loop can reach up to 350°C, and the pressure exceeds 15MPa. Since the reactor provides it with a higher neutron flux, the entire high-temperature and high-pressure irradiation test loop is similar to a "micro-reactor", which can not only carry out irradiation tests on fuels and materials, but also carry out tests such as the compatibility of materials with water quality. The high-temperature and high-pressure irradiation test loop has a wide range of uses in irradiation tests of fuels and materials.

[0003] The pH of the loop coolant, i.e., water, in the high-temperature and high-pressure irradiation test loop has a great influence on the corrosion of materials, the migration and deposition of deposits, and especially the release, migration and deposition of deposits on the fuel surface. The increase of fuel cladding deposits will accelerate the corrosion of cladding materials and deteriorate the heat transfer of the cladding. Therefore, how to control the pH value of water quality has become a technical problem that needs to be solved urgently by technicians in this field. Summary of the invention

[0004] The embodiment of the present application provides a method for controlling the pH value of boron-alkaline water quality in a high-temperature and high-pressure irradiation test loop. The method utilizes the relationship between boron element concentration and alkali concentration to adjust the pH value of boron-alkaline water quality to a preset pH value range. The pH control operation of the loop water quality is simple and easy to operate, and does not require large and complex dedicated water chemistry control facilities such as chemical volume systems. It produces less radioactive waste liquid and has high control accuracy. It can safely and efficiently ensure that the pH of low-boron alkaline water quality in the high-temperature and high-pressure irradiation test loop is within the limit range.

[0005] In a first aspect, the present application provides a method for controlling the pH value of boric alkaline water in a high temperature and high pressure irradiation test loop, wherein the boric alkaline water comprises boric acid, potassium hydroxide and lithium hydroxide, and the method comprises:

[0006] The boron element concentration and the alkali concentration are detected, wherein the alkali concentration includes the sum of the potassium hydroxide concentration and the lithium hydroxide concentration; and the pH value of the boron alkaline water is adjusted to a preset pH value range using the boron element concentration and the alkali concentration.

[0007] In some embodiments, the step of adjusting the pH value of the boron alkaline water to a preset pH value range by using the boron element concentration and the alkali concentration includes:

[0008] Determine a preset alkali concentration range corresponding to the boron concentration using a preset coordination curve according to the boron concentration, wherein the preset coordination curve is a curve formed according to the corresponding relationship between the boron concentration and the alkali concentration when the pH value of the boron alkaline water is within the preset pH value range;

[0009] When the alkali concentration is less than the minimum value in the preset alkali concentration range, adding potassium hydroxide and / or lithium hydroxide to the boron alkaline water to make the alkali concentration within the preset alkali concentration range;

[0010] When the alkali concentration is greater than the maximum value of the preset alkali concentration range, the alkali concentration is reduced by using a cationic bed so that the alkali concentration is within the preset alkali concentration range.

[0011] In some embodiments, the step of adjusting the pH value of the boron alkaline water to a preset pH value range by using the boron element concentration and the alkali concentration includes:

[0012] Determine a preset boron element concentration range corresponding to the alkali concentration using a preset coordination curve according to the alkali concentration, wherein the preset coordination curve is a curve formed according to the corresponding relationship between the boron element concentration and the alkali concentration when the pH value of the boron alkaline water is within the preset pH value range;

[0013] When the boron concentration is less than the minimum value in the preset boron concentration range, adding boric acid to the boric alkaline water to make the boron concentration within the preset boron concentration range;

[0014] When the boron element concentration is greater than the maximum value in the preset boron element concentration range, the boron element concentration is reduced by using a cathode bed so that the boron element concentration is within the preset boron element concentration range.

[0015] In some embodiments, the preset coordination curve includes a first curve and a second curve, wherein the first curve is a curve formed according to the corresponding relationship between the boron element concentration and the alkali concentration when the pH value of the boron alkaline water quality is the minimum value within the preset pH value range; the second curve is a curve formed according to the corresponding relationship between the boron element concentration and the alkali concentration when the pH value of the boron alkaline water quality is the maximum value within the preset pH value range;

[0016] The step of determining a preset alkali concentration range corresponding to the boron concentration by using a preset coordination curve according to the boron concentration comprises:

[0017] According to the boron element concentration, using the first curve, determining a minimum value of a preset concentration range corresponding to the boron element concentration;

[0018] According to the boron element concentration, the second curve is used to determine a maximum value of a preset concentration range corresponding to the boron element concentration.

[0019] In some embodiments, the preset coordination curve includes a first curve and a second curve, wherein the first curve is a curve formed according to the corresponding relationship between the boron element concentration and the alkali concentration when the pH value of the boron alkaline water quality is the minimum value within the preset pH value range; the second curve is a curve formed according to the corresponding relationship between the boron element concentration and the alkali concentration when the pH value of the boron alkaline water quality is the maximum value within the preset pH value range;

[0020] The step of determining a preset boron element concentration range corresponding to the alkali concentration by using a preset coordination curve according to the alkali concentration comprises:

[0021] According to the alkali concentration, using the first curve, determining a maximum value of a preset boron element concentration range corresponding to the alkali concentration;

[0022] According to the alkali concentration, the second curve is used to determine a minimum value of a preset boron element concentration range corresponding to the alkali concentration.

[0023] In some embodiments, the preset pH value range is 6.9-7.4.

[0024] In some embodiments, when the minimum value of the preset pH range is 6.9, the first curve is represented by the following formula:

[0025] y=0.0002x+0.0301;

[0026] Wherein, x is the boron concentration in mg / L; y is the alkali concentration in mmol / L.

[0027] In some embodiments, when the maximum value of the preset pH range is 7.4, the first curve is represented by the following formula:

[0028] y=0.0007x+0.0963;

[0029] Wherein, x is the boron concentration in mg / L; y is the alkali concentration in mmol / L.

[0030] In some embodiments, before the step of detecting the boron concentration and the alkali concentration, the method further comprises:

[0031] High-purity boric acid, lithium hydroxide monohydrate and potassium hydroxide are added to high-purity water to prepare boric alkaline water with an initial boric acid concentration of 50-500 mg / L and an initial alkali concentration of 0.0408-0.4188 mmol / L.

[0032] In some embodiments, the method further includes: using a cationic bed to reduce the alkali concentration so that the alkali concentration is within a preset alkali concentration range, and then switching the cationic bed to a boron-alkali mixed column to operate the boron-alkali mixed column.

[0033] The present application provides a method for controlling the pH value of boron-alkaline water quality in a high-temperature and high-pressure irradiation test loop. The method utilizes the relationship between boron element concentration and alkali concentration to adjust the pH value of boron-alkaline water quality to a preset pH value range. The pH control operation of the loop water quality is simple and easy to operate, and does not require large and complex dedicated water chemistry control facilities such as chemical volume systems. It produces less radioactive waste liquid and has high control accuracy. It can safely and efficiently ensure that the pH of low-boron alkaline water quality in the high-temperature and high-pressure irradiation test loop is within the limit range. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic flow chart of a method for controlling the pH value of boron alkaline water in a high-temperature and high-pressure irradiation test loop according to some embodiments is exemplified;

[0035] Figure 2 A schematic diagram of a first curve and a second curve provided according to some embodiments is exemplarily shown. DETAILED DESCRIPTION

[0036] In order to better understand the above technical solution, the technical solution of the present application is described in detail below through specific implementation methods.

[0037] After research, it was found that the pH of water at 300°C (i.e. pH 300℃ ) can be controlled between 6.9 and 7.4 to effectively reduce the corrosion of materials. However, due to the natural boron in water 10 B(n,α) 7 The nuclear reaction of Li will gradually increase the concentration of lithium in the water, causing the pH to gradually increase. In addition, as the impurity elements react with HBO in the boron resin and lithium resin, 3 - , Li + The exchange that occurs will also cause the pH value of the water to deviate.

[0038] In the related art, there are two methods for pH control in large pressurized water commercial nuclear power plants: the boron-lithium system and the boron-potassium-ammonium system. The initial boron concentration is relatively high, and the initial boron concentration can reach more than 2000 mg / L (depending on the reactor type). In order to better control and adjust the pH, large commercial reactors are equipped with chemical volume systems and dosing systems, which use dilution or supplementation of chemical reagents to control the pH of the water quality within the limit. This method has high requirements for the hardware configuration of the equipment, and the dilution method will also produce a large amount of radioactive waste liquid. In addition, due to the upper limit of lithium in large commercial pressurized water reactors, the initial pH of the reactor controlled by natural boron is 300℃ It is often lower than 6.9. Since the high temperature and high pressure irradiation test circuit is generally small in size, about 1m 3 , 10 B(n,α) 7 The nuclear reaction of Li and the exchange of impurity ions with cations in the purification resin will cause the concentrations of boron and lithium to gradually deviate from the boron-base coordination curve, causing pH 300℃ Deviation occurs. Compared with large commercial pressurized water reactors, due to the limitation of the space between processes in the high-temperature and high-pressure irradiation test loop, the high-temperature and high-pressure irradiation test loop does not have dedicated facilities for water chemistry control such as a chemical volume system, and does not have the conditions for using a large-volume dilution method to adjust and control the boric acid in the embodiment of the present application. At the same time, due to the small volume of the loop, a slight disturbance of the boric acid content may cause the pH to exceed the control range. All of these have brought huge challenges to the accurate and stable control of the pH value of the loop water quality.

[0039] In order to solve the above technical problems, an embodiment of the present application provides a method for controlling the pH value of boron alkaline water quality in a high-temperature and high-pressure irradiation test loop. The method utilizes the relationship between boron element concentration and alkali concentration to adjust the pH value of boron alkaline water quality to a preset pH value range. The pH control operation of the loop water quality is simple, and does not require large and complex dedicated water chemistry control facilities such as chemical volume systems. It produces less radioactive waste liquid and has high control accuracy. It can safely and efficiently ensure that the pH of low-boron alkaline water quality in the high-temperature and high-pressure irradiation test loop is within the limit range.

[0040] Figure 1 The schematic flow chart of a method for controlling the pH value of boric alkaline water in a high temperature and high pressure irradiation test loop according to some embodiments is exemplarily shown. The boric alkaline water includes boric acid, potassium hydroxide and lithium hydroxide, and the method includes S100-S200.

[0041] S100, detecting the boron element concentration and the alkali concentration, where the alkali concentration includes the sum of the potassium hydroxide concentration and the lithium hydroxide concentration.

[0042] In the embodiment of the present application, during the normal operation of the loop, the sampling frequency is maintained at 1 to 3 times a week, and the boron concentration and alkali concentration in the water quality are detected after sampling. In addition, sampling is required after water replenishment, lithium removal by opening the cation bed (hydrogen type), boron removal by opening the anion bed (hydroxyl type), lithium hydroxide addition, potassium hydroxide addition, boric acid addition, etc., and the boron concentration and alkali concentration in the water quality are detected after sampling. This S100 step can be called a monitoring scheme for boron alkali concentration in loop water.

[0043] In some embodiments, before the step of detecting the boron element concentration and the alkali concentration, it also includes: adding high-purity boric acid, lithium hydroxide monohydrate and potassium hydroxide to high-purity water to obtain boron alkaline water with an initial boric acid concentration of 50-500 mg / L and an initial alkali concentration of 0.0408-0.4188 mmol / L. The pH value of the boron alkaline water after configuration is between 6.9-7.4. This step can be called the preparation scheme of loop source water.

[0044] S200, using the boron element concentration and the alkali concentration, adjusting the pH value of the boron alkaline water to a preset pH value range. The step S200 can be called a solution for adjusting the boron alkali concentration in the loop water.

[0045] In some embodiments, the boron concentration can be fixed, and the alkali concentration can be adjusted so that the pH value of the boron alkaline water is within a preset pH range. Specifically, the step of adjusting the pH value of the boron alkaline water to a preset pH range using the boron concentration and the alkali concentration includes:

[0046] Determine a preset alkali concentration range corresponding to the boron concentration using a preset coordination curve according to the boron concentration, wherein the preset coordination curve is a curve formed according to the corresponding relationship between the boron concentration and the alkali concentration when the pH value of the boron alkaline water is within a preset pH value range;

[0047] When the alkali concentration is less than the minimum value in the preset alkali concentration range, potassium hydroxide and / or lithium hydroxide are added to the boron alkaline water to make the alkali concentration within the preset alkali concentration range. 7 The Li abundance is 99.9% lithium hydroxide.

[0048] When the alkali concentration is greater than the maximum value of the preset alkali concentration range, the alkali concentration is reduced by using a cationic bed so that the alkali concentration is within the preset alkali concentration range.

[0049] Exemplarily, the boron element concentration is 196mg / L, the minimum value of the preset alkali concentration range is 0.0693mmol / L, and the maximum value of the preset alkali concentration range is 0.2225mmol / L. If the alkali concentration is less than the minimum value in the preset alkali concentration range, that is, less than 0.0693mmol / L, potassium hydroxide and / or lithium hydroxide can be added to the water quality through a chemical reagent addition system to increase the alkali concentration so that the alkali concentration is within the preset alkali concentration range. If the alkali concentration is greater than the maximum value in the preset alkali concentration range, that is, greater than 0.2225mmol / L, a cationic bed can be put into purification to remove excess alkali, that is, to reduce the alkali concentration so that the alkali concentration is within the preset alkali concentration range. In an embodiment of the present application, when the alkali concentration does not exceed the preset alkali concentration range, the boron alkali mixed column, that is, the boron alkali mixed ion exchange resin bed is started. In some embodiments, the alkali concentration is reduced by using a cationic bed so that the alkali concentration is within the preset alkali concentration range, and then the cationic bed is switched to a boron alkali mixed column to operate the boron alkali mixed column.

[0050] In the embodiment of the present application, sampling is required after the cation bed is put into use to determine whether the alkali concentration is within the preset alkali concentration range. If it is within the preset alkali concentration range, the cation bed can be switched to a boron-alkali mixed column. The specific sampling time can be determined according to the purification capacity of the resin in the cation bed. The purification time and flow rate can be determined. When the purification time is reached, sampling can be performed, so that the sampling time can be accurately determined to avoid unnecessary concentration detection.

[0051] In some embodiments, the preset coordination curve includes a first curve and a second curve, wherein the first curve is a curve formed according to the corresponding relationship between the boron element concentration and the alkali concentration when the pH value of the boron alkaline water quality is the minimum value within the preset pH value range; the second curve is a curve formed according to the corresponding relationship between the boron element concentration and the alkali concentration when the pH value of the boron alkaline water quality is the maximum value within the preset pH value range. Exemplarily, Figure 2 The schematic diagram of the first curve and the second curve provided according to some embodiments is exemplarily shown. Figure 2 In the figure, the first curve is a curve marked with ph = 6.9, and the second curve is a curve marked with ph = 7.4. The abscissa of the first curve and the second curve is the concentration of the boron element, and the ordinate is the concentration of the alkali.

[0052] In some embodiments, the step of determining a preset alkali concentration range corresponding to the boron concentration using a preset coordination curve according to the boron concentration comprises:

[0053] According to the boron element concentration, using the first curve, determining a minimum value of a preset alkali concentration range corresponding to the boron element concentration;

[0054] According to the boron element concentration, the second curve is used to determine a maximum value of a preset alkali concentration range corresponding to the boron element concentration.

[0055] In some embodiments, when the minimum value of the preset pH range is 6.9, the first curve is represented by the following formula: y=0.0002x+0.0301; wherein x is the boron concentration in mg / L; and y is the alkali concentration in mmol / L.

[0056] Exemplarily, when the boron concentration is 196 mg / L, the minimum value of the preset alkali concentration range corresponding to the boron concentration determined by the first curve is 0.0693 mmol / L.

[0057] In some embodiments, when the maximum value of the preset pH range is 7.4, the first curve is represented by the following formula: y=0.0007x+0.0963; wherein x is the boron concentration in mg / L; and y is the alkali concentration in mmol / L.

[0058] In some embodiments, the alkali concentration can be fixed, and the boron concentration can be adjusted so that the pH value of the boron alkaline water is within a preset pH range. Specifically, the step of adjusting the pH value of the boron alkaline water to within a preset pH range using the boron concentration and the alkali concentration includes:

[0059] Determine a preset boron element concentration range corresponding to the alkali concentration using a preset coordination curve according to the alkali concentration, wherein the preset coordination curve is a curve formed according to the corresponding relationship between the boron element concentration and the alkali concentration when the pH value of the boron alkaline water is within a preset pH value range;

[0060] When the boron concentration is less than the minimum value in the preset boron concentration range, boric acid is added to the boron alkaline water to make the boron concentration within the preset boron concentration range. In one example, the added boric acid is nuclear grade boric acid.

[0061] When the boron element concentration is greater than the maximum value in the preset boron element concentration range, the boron element concentration is reduced by using a cathode bed so that the boron element concentration is within the preset boron element concentration range.

[0062] In the embodiment of the present application, when the boron concentration does not exceed the preset boron concentration range, the boron-alkali mixed column, i.e., the boron-alkali mixed ion exchange resin bed, is started to operate. In some embodiments, the boron concentration is reduced by using an anion bed so that the alkali concentration is within the preset boron concentration range, and then the anion bed is switched to a boron-alkali mixed column to operate the boron-alkali mixed column.

[0063] In the embodiment of the present application, sampling is required after the anion bed is put into use to determine whether the boron concentration is within the preset boron concentration range. If it is within the preset boron concentration range, the anion bed can be switched to a boron-alkali mixed column. The specific sampling time can be determined according to the purification capacity of the resin in the anion bed to determine the purification time and flow rate. When the purification time is reached, sampling can be performed, so that the sampling time can be accurately determined to avoid unnecessary concentration detection.

[0064] In some embodiments, the step of determining a preset boron element concentration range corresponding to the alkali concentration using a preset coordination curve according to the alkali concentration comprises:

[0065] According to the alkali concentration, the first curve is used to determine the maximum value of the preset boron element concentration range corresponding to the alkali concentration; according to the alkali concentration, the second curve is used to determine the minimum value of the preset boron element concentration range corresponding to the alkali concentration.

[0066] In this embodiment, it is equivalent to controlling the alkali concentration to remain unchanged and adjusting the boron concentration to be within the preset boron concentration range. Since the first curve and the second curve have been introduced above, they will not be repeated here. The y values ​​of the first curve and the second curve are determined to be constant values, and the corresponding x values ​​are calculated. The x value calculated on the first curve is used as the maximum value of the preset boron concentration range, and the x value calculated on the second curve is used as the minimum value of the preset boron concentration range.

[0067] In the embodiment of the present application, for alkaline water with small volume and gradually increasing lithium content, a pH value is provided. 300℃ The method of stably and accurately controlling the pH value within the range of 6.9 to 7.4 includes a preparation scheme for loop source water, a monitoring scheme for boric alkali concentration in loop water, and a regulation scheme for boric alkali concentration in loop water. During normal operation of the loop, the concentration of boric alkali in the loop water is sampled and analyzed regularly. With reference to the preset coordination curve, the method of adjusting the alkali by fixing the boric acid concentration or the method of adjusting the boron concentration by fixing the alkali concentration can be selected. The pH value of the water quality is controlled within the limit range by using the loop purification system and the dosing system. The method is loop-friendly, easy to operate, accurate in control, and produces less radioactive waste liquid. It can safely and efficiently guarantee the pH value control of the low-boron alkaline water quality of the test loop under high temperature and high pressure conditions. The hardware configuration requirements of the water chemical equipment specially set for loop water quality control are low, easy to operate, and accurate in control. It has been successfully applied to the pH value control of boric alkaline water quality in a test loop. This method can also be applied to the pH value control of alkaline water quality in similar nuclear facilities.

[0068] The method in the embodiment of the present application can meet the requirements for pH control of low-boron alkaline water in a high-temperature and high-pressure irradiation test loop, and the method has the following beneficial effects: 1) The method can control the pH of the alkaline water in the high-temperature and high-pressure irradiation test loop. 300℃1) The method of the present invention can be precisely controlled within the range of 6.9 to 7.4; 2) The method developed by the present invention can control the boron concentration in the loop within the range of 50 to 500 mg / L for coordinated control of boron alkali, with a small pH fluctuation range and precise control; 3) No complex dedicated chemical volume system and other equipment are required, which simplifies the loop design and equipment, and the process flow is concise and easy to operate; 4) Compared with the traditional dilution method, almost no additional radioactive waste liquid is generated.

[0069] In summary, the present invention provides a method for controlling the pH value of boron-alkaline water quality in a high-temperature and high-pressure irradiation test loop. The method utilizes the relationship between boron element concentration and alkali concentration to adjust the pH value of boron-alkaline water quality to a preset pH value range. The pH control operation of the loop water quality is simple, and does not require large and complex dedicated water chemistry control facilities such as chemical volume systems. It produces less radioactive waste liquid and has high control accuracy. It can safely and efficiently ensure that the pH of low-boron alkaline water quality in the high-temperature and high-pressure irradiation test loop is within the limit range.

[0070] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed. The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application. The above are only preferred implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A method for controlling the pH value of boric alkaline water in a high temperature and high pressure irradiation test circuit, characterized in that: The boric alkaline water comprises boric acid, potassium hydroxide and lithium hydroxide, and the method comprises: detecting a boron element concentration and an alkali concentration, wherein the alkali concentration includes a sum of a potassium hydroxide concentration and a lithium hydroxide concentration; The pH value of the boron alkaline water is adjusted to within a preset pH value range by utilizing the boron element concentration and the alkali concentration.

2. The method according to claim 1, characterized in that The step of adjusting the pH value of the boron alkaline water to a preset pH value range by using the boron element concentration and the alkali concentration comprises: Determine a preset alkali concentration range corresponding to the boron concentration using a preset coordination curve according to the boron concentration, wherein the preset coordination curve is a curve formed according to the corresponding relationship between the boron concentration and the alkali concentration when the pH value of the boron alkaline water is within the preset pH value range; When the alkali concentration is less than the minimum value in the preset alkali concentration range, adding potassium hydroxide and / or lithium hydroxide to the boron alkaline water to make the alkali concentration within the preset alkali concentration range; When the alkali concentration is greater than the maximum value of the preset alkali concentration range, the alkali concentration is reduced by using a cationic bed so that the alkali concentration is within the preset alkali concentration range.

3. The method according to claim 1, characterized in that The step of adjusting the pH value of the boron alkaline water to a preset pH value range by using the boron element concentration and the alkali concentration comprises: Determine a preset boron element concentration range corresponding to the alkali concentration using a preset coordination curve according to the alkali concentration, wherein the preset coordination curve is a curve formed according to the corresponding relationship between the boron element concentration and the alkali concentration when the pH value of the boron alkaline water is within the preset pH value range; When the boron concentration is less than the minimum value in the preset boron concentration range, adding boric acid to the boric alkaline water to make the boron concentration within the preset boron concentration range; When the boron element concentration is greater than the maximum value in the preset boron element concentration range, the boron element concentration is reduced by using a cathode bed so that the boron element concentration is within the preset boron element concentration range.

4. The method according to claim 2, characterized in that: The preset coordination curve includes a first curve and a second curve, wherein the first curve is a curve formed according to the corresponding relationship between the boron element concentration and the alkali concentration when the pH value of the boron alkaline water quality is the minimum value within the preset pH value range; the second curve is a curve formed according to the corresponding relationship between the boron element concentration and the alkali concentration when the pH value of the boron alkaline water quality is the maximum value within the preset pH value range; The step of determining a preset alkali concentration range corresponding to the boron concentration by using a preset coordination curve according to the boron concentration comprises: According to the boron element concentration, using the first curve, determining a minimum value of a preset alkali concentration range corresponding to the boron element concentration; According to the boron element concentration, the second curve is used to determine a maximum value of a preset alkali concentration range corresponding to the boron element concentration.

5. The method according to claim 3, characterized in that: The preset coordination curve includes a first curve and a second curve, wherein the first curve is a curve formed according to the corresponding relationship between the boron element concentration and the alkali concentration when the pH value of the boron alkaline water quality is the minimum value within the preset pH value range; the second curve is a curve formed according to the corresponding relationship between the boron element concentration and the alkali concentration when the pH value of the boron alkaline water quality is the maximum value within the preset pH value range; The step of determining a preset boron element concentration range corresponding to the alkali concentration by using a preset coordination curve according to the alkali concentration comprises: According to the alkali concentration, using the first curve, determining a maximum value of a preset boron element concentration range corresponding to the alkali concentration; According to the alkali concentration, the second curve is used to determine a minimum value of a preset boron element concentration range corresponding to the alkali concentration.

6. The method according to claim 4 or 5, characterized in that: The water quality is at 300° C. and the preset pH value range is 6.9-7.

4.

7. The method according to claim 6, characterized in that When the minimum value of the preset pH value range is 6.9, the first curve is expressed by the following formula: y=0.0002x+0.0301; Wherein, x is the concentration of boron element, in mg / L; y is the concentration of alkali, in mmol / L.

8. The method according to claim 6, characterized in that When the maximum value of the preset pH value range is 7.4, the first curve is expressed by the following formula: y=0.0007x+0.0963; Wherein, x is the boron concentration in mg / L; y is the alkali concentration in mmol / L.

9. The method according to claim 1, characterized in that: Before the step of detecting the boron concentration and the alkali concentration, the method further comprises: High-purity boric acid, lithium hydroxide monohydrate and potassium hydroxide are added to high-purity water to prepare boric alkaline water with an initial boric acid concentration of 50-500 mg / L and an initial alkali concentration of 0.0408-0.4188 mmol / L.

10. The method according to claim 2, characterized in that Also includes: After the alkali concentration is reduced by using the cationic bed so that the alkali concentration is within a preset alkali concentration range, the cationic bed is switched to a boron-alkali mixed column to operate the boron-alkali mixed column.

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