Methods, devices, equipment, media and program products for determining primary circuit water chemistry

Abstract

The present application relates to the field of primary-loop water chemistry control technology, and in particular to a primary-loop water chemistry determination method, device, equipment, medium and program product. It is used to solve the problem of inaccurate prediction of primary-loop water chemistry conditions in related technologies. A primary-loop water chemistry determination method, including: obtaining the concentration of unionized boric acid and unionized lithium hydroxide in primary-loop water at the current measurement temperature, and the saturated solubility of each metal element in the primary-loop water except lithium in the primary-loop water; constructing a first function based on the conservation of ionic charge, the ion product formula of boric acid and lithium hydroxide in primary-loop water, and the concentration of unionized boric acid and unionized lithium hydroxide, the first function is used to characterize the corresponding relationship between the total concentration of lithium hydroxide and the pH value; calculating the current pH value of the primary-loop water based on the first function and the current measured total concentration of lithium hydroxide.

Description

Technical Field

[0001] The present application relates to the technical field of primary-loop water chemistry control, and in particular to a primary-loop water chemistry determination method, device, equipment, medium and program product. Background Art

[0002] The primary water chemistry of a nuclear reactor has a significant impact on steam generator corrosion, corrosion product release, and fuel rod fouling, which directly affects the reactivity of the fuel rods and the safety of the reactor. Therefore, it is of great significance to establish a calculation method for accurately predicting the primary water chemistry of the reaction pair.

[0003] At present, the pH value of the primary water chemical parameter in nuclear power plants is calculated using an empirical formula, which does not take into account the possible reaction mechanisms in the primary water that affect the pH value change. The calculation results are inaccurate and cannot accurately predict the impact of primary water chemistry on steam generator corrosion, etc., and thus cannot accurately predict the reaction performance of fuel rods and reactor safety. Summary of the invention

[0004] Based on this, the present application provides a method, device, equipment, medium and program product for determining the water chemistry of a single loop to solve the problem in the related art that the prediction of the water chemistry conditions of a single loop is not accurate enough, thereby failing to accurately predict the reaction performance of the fuel rods and the safety of the reactor.

[0005] In a first aspect of the present application, a method for determining water chemistry in a circuit is provided, comprising:

[0006] Obtain the concentrations of unionized boric acid and unionized lithium hydroxide in the primary water loop at the current measurement temperature, as well as the saturated solubility of other metal elements in the primary water loop except lithium;

[0007] According to the conservation of ionic charge, the ion product formula of boric acid and lithium hydroxide in the primary water, and the concentrations of unionized boric acid and unionized lithium hydroxide, a first function is constructed, and the first function is used to characterize the corresponding relationship between the total concentration of lithium hydroxide and the pH value;

[0008] The current pH value of the primary circuit water is calculated based on the first function and the currently measured total concentration of lithium hydroxide.

[0009] In a possible implementation of the first aspect, calculating the current pH value of the primary circuit water according to the first function and the current measured total concentration of lithium hydroxide includes:

[0010] Calculate the reference total concentration of lithium hydroxide corresponding to the reference pH value according to the first function and the reference pH value of the primary circuit water;

[0011] The reference pH value is used as the initial value of pH iteration. According to the current measured total concentration of lithium hydroxide, the first function and the iterative algorithm, the initial value of pH iteration is corrected i times until the absolute value of the difference between the current pH value and the i-th pH correction value is less than or equal to a preset threshold value, i is an integer greater than or equal to 1, and during the i-time correction process, the last pH correction value is used as the initial value of pH iteration for the next correction.

[0012] In a possible implementation of the first aspect, the iterative algorithm satisfies the following formula (1):

[0013]

[0014] In formula (1), pH represents the current pH value, pH 0 Indicates the initial value of pH iteration in each calibration process, [LiOH] bulk Indicates the current measured total concentration of lithium hydroxide, [LiOH] 0 Indicates the total concentration of lithium hydroxide during each calibration process, [LiOH] 0 and pH 0 The first function is satisfied, and n represents a preset threshold.

[0015] In a possible implementation manner of the first aspect, obtaining the concentration of unionized boric acid in primary circuit water at a current measurement temperature includes:

[0016] According to the ion product formula of boric acid in primary-loop water and the mass conservation of boron element, the concentration of unionized boric acid in primary-loop water at the current measuring temperature is calculated.

[0017] In a possible implementation of the first aspect, the calculation formula for the ion product of boric acid in the primary water circuit satisfies formulas (2), (3), (4), (5), (6) and (7):

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] Wherein, in formula (2), formula (3), formula (4), formula (5), formula (6) and formula (7), [B(OH) - 4] represents B(OH) - 4 The molar concentration of [OH - ] indicates OH in the primary water - The molar concentration of [B(OH) 3 ] represents the molar concentration of unionized boric acid, K 1 B represents the primary ionization constant of boric acid; [B 2 (OH) - 7 ] means B 2 (OH) - 7 The molar concentration, K 2 B represents the secondary ionization constant of boric acid; [B 3 (OH) - 10 ] means B 3 (OH) - 10 The molar concentration, K 3 B represents the tertiary ionization constant of boric acid, and T represents the current measurement temperature;

[0025] The calculation formula for the concentration of unionized boric acid satisfies formula (8):

[0026]

[0027] In formula (8), x represents the molar concentration of unionized boric acid, and [B] represents the total molar concentration of boric acid.

[0028] In a possible implementation manner of the first aspect, obtaining the concentration of unionized lithium hydroxide in the primary circuit water at the current measurement temperature includes:

[0029] The concentration of unionized lithium hydroxide is calculated based on the ion product formula of lithium hydroxide, the total concentration of lithium hydroxide, and the degree of ionization of lithium hydroxide at the current measurement temperature.

[0030] In a possible implementation of the first aspect,

[0031] The ion product formula of lithium hydroxide satisfies formulas (9) and (10):

[0032]

[0033] log K j =-0.8217-0.0031T (10)

[0034] In formulas (9) and (10), K jrepresents the ionic product of lithium hydroxide, [Li + ] indicates Li + The molar concentration of [OH - ] represents the molar concentration of OH- in the primary water circuit, [LiOH] represents the molar concentration of unionized lithium hydroxide, and T represents the current measurement temperature;

[0035] The calculation formula for the concentration of the unionized lithium hydroxide satisfies formula (11):

[0036] [LiOH]=[LiOH] bulk (1-α LiOH ) (11)

[0037] In formula (11), [LiOH] bulk Represents the current measured total concentration of lithium hydroxide, α LiOH Indicates the current degree of ionization of lithium hydroxide.

[0038] In a possible implementation of the first aspect, determining the saturated solubility of each metal element in the primary-loop water except lithium at the current measurement temperature includes:

[0039] Obtain the Gibbs free energy of the precipitation and dissolution chemical reaction of the stable solid phase of each metal element in the primary water except lithium at the current measurement temperature;

[0040] According to the precipitation dissolution chemical reaction and Gibbs free energy, calculate the ion concentration corresponding to the remaining metal elements;

[0041] According to the element type, the ion concentration corresponding to each of the remaining metal elements is accumulated respectively to obtain the saturated solubility of the remaining metal elements in the primary water circuit.

[0042] In a possible implementation of the first aspect, the first function satisfies formula (14):

[0043]

[0044] In formula (14), [LiOH] bulk Represents the current measured total concentration of lithium hydroxide, K w represents the ionic product of water, [H + ] indicates H + The molar concentration in the primary water circuit, K 1 B represents the primary ionization constant of boric acid; K 2 B represents the secondary ionization constant of boric acid; K 3 Brepresents the tertiary dissociation constant of boric acid, x represents the molar concentration of unionized boric acid, K j represents the ionic product of lithium hydroxide.

[0045] In a second aspect, the present application provides a primary water chemistry determination device, comprising:

[0046] An acquisition module is used to acquire the concentration of unionized boric acid and unionized lithium hydroxide in the primary water loop at the current measurement temperature, and the saturated solubility of other metal elements in the primary water loop except lithium;

[0047] A construction module is used to construct a first function based on ion charge conservation, an ion product formula of boric acid and lithium hydroxide in primary water, and the concentrations of unionized boric acid and unionized lithium hydroxide, wherein the first function is used to characterize the corresponding relationship between the total concentration of lithium hydroxide and the pH value;

[0048] The calculation module is used to calculate the current pH value of the primary circuit water according to the first function and the current measured total concentration of lithium hydroxide.

[0049] In a third aspect, the present application provides a computer device, comprising: a processor and a memory, the memory being configured to store computer program instructions;

[0050] When the computer program instructions are executed by a processor, the computer is caused to perform the steps of the method described in the first aspect.

[0051] In a fourth aspect, the present application provides a computer-readable storage medium, which stores computer program instructions. When the computer program instructions are executed on a computer, a processor executes the steps of the method described in the first aspect.

[0052] In a fifth aspect, the present application provides a computer program product, including a computer program, which implements the steps of the method described in the first aspect when executed by a processor.

[0053] The present application provides a method for determining the chemistry of primary water. By obtaining the concentration of unionized boric acid and unionized lithium hydroxide in primary water at the current measurement temperature, and the saturated solubility of each metal element in primary water except lithium in primary water, and using the conservation of ionic charge, the ion product formula of boric acid and lithium hydroxide in primary water, and the concentration of unionized boric acid and unionized lithium hydroxide, a functional relationship between the total concentration of lithium hydroxide and the pH value is constructed. When calculating the pH value, the possible reaction mechanism affecting the pH change in primary water is considered, and the calculation result is accurate, so that the influence of the pH change of primary water on the corrosion of steam generators can be accurately predicted, and then an accurate reference can be provided for the reaction performance of fuel rods and the safety of reactors. At the same time, by determining the saturated solubility of metal elements in primary water, the corrosion of alloy materials outside the reactor and the fouling behavior of fuel rods can also be predicted, so that a reference can be further provided for the reaction performance of fuel rods and the safety of reactors. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A schematic diagram of a process for determining water chemistry in a single circuit provided in an embodiment of the present application;

[0055] Figure 2 A schematic diagram of another method for determining water chemistry in a single loop provided in an embodiment of the present application;

[0056] Figure 3 A schematic diagram of E-pH of nickel ferrite at 558K provided in an embodiment of the present application;

[0057] Figure 4 A comparison chart of the pH value calculated by the present application and the pH value of the reference example provided in the present application;

[0058] Figure 5 A structural block diagram of a primary circuit water chemistry determination device provided in an embodiment of the present application;

[0059] Figure 6 A structural block diagram of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0060] In order to facilitate the understanding of the present application, the present application will be described more comprehensively with reference to the relevant drawings below. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0062] In order to solve the problem of inaccurate prediction of the primary water chemistry conditions, the inventors propose a new method for determining and calculating the primary water chemistry, which is described in detail as follows:

[0063] The present application discloses a method for determining the water chemistry of a circuit, such as Figure 1 and Figure 2 As shown, including:

[0064] S11), obtaining the concentration of unionized boric acid and unionized lithium hydroxide in the primary water at the current measurement temperature, and the saturated solubility of each metal element in the primary water except lithium in the primary water.

[0065] The primary circuit water is also called the primary circuit coolant. Its main function is to bring the heat generated by the reactor core to the steam generator and transfer it to the secondary circuit to produce steam.

[0066] Boric acid is added to the primary water circuit to control reactivity changes and thus control reactor power and safety.

[0067] When the primary loop water is alkaline, it can improve the corrosion resistance of structural materials and reduce the transfer of corrosion products to the core and the activation of corrosion products. The pH of the primary loop water is controlled by adding lithium hydroxide.

[0068] Boric acid is a weak electrolyte. The size of the ionization equilibrium constant reflects the degree of ionization of the weak electrolyte. The degree of ionization varies at different temperatures.

[0069] Lithium hydroxide is a sparingly soluble electrolyte. The ion product of a sparingly soluble electrolyte reflects the degree of ionization of the electrolyte. The degree of ionization varies at different temperatures.

[0070] In addition to lithium, primary water also contains metal elements such as Ni, Fe, Cr, Co, and Mn. The saturated solubility of these metal elements has an important influence on the corrosion of the alloy materials outside the reactor and the scaling behavior of the fuel rod surface, and their saturated solubility will affect the conservation of ion charge in primary water, thereby indirectly affecting the pH value of primary water. The current measured temperature can be any possible temperature of the primary water during normal operation.

[0071] Based on the above, the concentrations of unionized boric acid and unionized lithium hydroxide in the primary water at the current measurement temperature, as well as the saturated solubility of the remaining metal elements in the primary water except lithium, can be determined by the ionization reaction of the substances contained in the primary water at the current measurement temperature, and the concentrations of the ions after ionization.

[0072] In some embodiments, obtaining the concentration of unionized boric acid in primary water at the current measurement temperature may include:

[0073] According to the ion product formula of boric acid in primary-loop water and the mass conservation of boron element, the concentration of unionized boric acid in primary-loop water at the current measuring temperature is calculated.

[0074] Among them, since the ionization reaction of boric acid in the primary water circuit satisfies equations (1), (2) and (3):

[0075]

[0076]

[0077]

[0078] Therefore, the calculation formula for the ion product of boric acid in primary water circuit satisfies formulas (2), (3), (4), (5), (6) and (7):

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085] Wherein, in formula (2), formula (3), formula (4), formula (5), formula (6) and formula (7), [B(OH) - 4 ] represents B(OH) - 4 The molar concentration of [OH - ] indicates OH in the primary water - The molar concentration of [B(OH) 3 ] represents the molar concentration of unionized boric acid, K 1 B represents the primary ionization constant of boric acid; [B2 (OH) - 7 ] means B 2 (OH) - 7 The molar concentration, K 2 B represents the secondary ionization constant of boric acid; [B 3 (OH) - 10 ] means B 3 (OH) - 10 The molar concentration, K 3 B represents the tertiary ionization constant of boric acid, and T represents the current measurement temperature;

[0086] According to the above formula and the conservation of mass of boron element, the calculation formula of the concentration of unionized boric acid can be obtained to satisfy formula (8):

[0087]

[0088] In formula (8), x represents the molar concentration of unionized boric acid, and [B] represents the total molar concentration of boric acid (ie, the total molar concentration of boron element).

[0089] The unit of T may be degrees Celsius.

[0090] Based on the above boric acid ionization reaction and ion product formula, as well as the total molar concentration of boron element, the molar concentration of unionized boric acid in the primary circuit water can be accurately calculated.

[0091] Similarly, the concentration of unionized lithium hydroxide in primary-loop water can also be calculated based on the ionization reaction of lithium hydroxide in primary-loop water, the ion product formula, and the conservation of mass of lithium element.

[0092] In some embodiments of the present application, obtaining the concentration of unionized lithium hydroxide in primary circuit water at the current measurement temperature includes:

[0093] The concentration of unionized lithium hydroxide is calculated based on the ion product formula of lithium hydroxide, the total concentration of lithium hydroxide, and the degree of ionization of lithium hydroxide at the current measurement temperature.

[0094] Wherein, the ionization reaction of lithium hydroxide satisfies equation (4):

[0095] LiOH→Li + +OH - (4)

[0096] Therefore, the ion product formula of lithium hydroxide satisfies formulas (9) and (10):

[0097]

[0098] log K j =-0.8217-0.0031T (10)

[0099] In formulas (9) and (10), K j represents the ionic product of lithium hydroxide, [Li + ] indicates Li + The molar concentration of [OH - ] represents the molar concentration of OH- in the primary water circuit, [LiOH] represents the molar concentration of unionized lithium hydroxide, and T represents the current measurement temperature;

[0100] According to the above formulas (9) and (10), as well as the total concentration of lithium hydroxide (such as the total molar concentration) and the degree of ionization of lithium hydroxide at the current measurement temperature, the calculation formula for the molar concentration of unionized lithium hydroxide can be obtained to satisfy formula (11):

[0101] [LiOH]=[LiOH] bulk (1-α LiOH ) (11)

[0102] In formula (11), [LiOH] bulk Represents the current measured total concentration of lithium hydroxide, α LiOH Indicates the current degree of ionization of lithium hydroxide.

[0103] By calculating the concentration of unionized lithium hydroxide using the total concentration of lithium hydroxide and the current degree of ionization, the calculation accuracy of the concentration of unionized lithium hydroxide can be further improved.

[0104] The degree of ionization of the lithium hydroxide at the current measurement temperature can be obtained by looking up a table or by empirical calculation, which is not specifically limited here.

[0105] In some embodiments, the calculation formula for the current degree of ionization of potassium hydroxide satisfies the following formula (i):

[0106]

[0107] In formula (i), K j represents the ionic product of lithium hydroxide, [OH - ] represents the molar concentration of OH- in the primary water circuit, K w It represents the ion product of water at the current measurement temperature, [H + ] indicates H + The molar concentration in the primary water circuit.

[0108] Among them, the above K wIt can be obtained by looking up a table or by calculating using an empirical formula.

[0109] In some embodiments, the ionic product of water is calculated using the Marshall-Frank empirical formula (ii):

[0110] In formula (ii), T represents the current measured temperature in K; ρ w Indicates the density of water in g / cm 3 .

[0111] In some embodiments, determining the saturated solubility of each metal element in the primary loop water except lithium at the current measurement temperature includes:

[0112] Obtain the Gibbs free energy of the precipitation-dissolution chemical reaction corresponding to the stable solid state of each metal element except lithium in the primary water at the current measurement temperature; calculate the ion concentration corresponding to the remaining metal elements based on the precipitation-dissolution chemical reaction and Gibbs free energy; and accumulate the ion concentration corresponding to each of the remaining metal elements according to the type of element to obtain the saturated solubility of the remaining metal elements in the primary water.

[0113] Among them, it should be noted that metals have solid phase reactions in aqueous solutions. In these solid phase reactions, metals can exist in aqueous solutions in solid phases with different oxidation states. Depending on the positive or negative Gibbs free energy of the solid phase reaction, the solid phase reaction will proceed to the left or right. The solid phase corresponding to the reaction product after the solid phase reaction proceeds to the left or right is the stable solid phase corresponding to the metal element.

[0114] The precipitation-dissolution chemical reaction refers to the above-mentioned solid phase reaction. The concentration of the metal element corresponding to the dissolved substance containing the metal element generated in the solid phase reaction is the ion concentration corresponding to the metal element.

[0115] In some embodiments, determining the stable solid phase corresponding to each metal element in the primary water except lithium at the current measurement temperature may include:

[0116] According to all solid phase reactions of other metal elements in aqueous solution and the Gibbs free energy corresponding to all solid phase reactions, the stable solid phase corresponding to other metal elements is determined by using dissolved hydrogen and dissolved oxygen.

[0117] Specifically, according to the TERummery theory, all solid phase reactions of each of the remaining metal elements in aqueous solution satisfy equations (5) and (6):

[0118] aA+ZH2 =bB+cH 2 O (5)

[0119] bB+Z′O 2 =aA (6)

[0120] In equations (5) and (6), A and B represent any two solid phases of different oxidation states of any metal element in aqueous solution, and a, b, c, Z and Z' are coefficients.

[0121] The Gibbs free energy of the above two reactions satisfies formula (12):

[0122]

[0123] In formula (12), ΔG T represents the Gibbs free energy under standard conditions, R represents the equilibrium constant, T represents the current measurement temperature, and Q represents the reaction entropy;

[0124] Where Q = 1 / P H2 Z Or Q = 1 / P O2 Z , P H2 and P O2 Represent the partial pressures of hydrogen and oxygen respectively.

[0125] According to Henry's law, if the actual hydrogen or oxygen content is greater than the corresponding equilibrium value, ΔG T When the dissolved hydrogen (DH) and dissolved oxygen (DO) are given, the stable solid phases in which various metal elements other than lithium can be stably present in the reactor primary water can be determined.

[0126] After the stable solid phase is determined, the precipitation-dissolution chemical reaction corresponding to the stable solid phase can be determined according to the stable solid phase.

[0127] Specifically, the E-pH diagrams within the range of multiple actual operating conditions can be comprehensively analyzed to determine the precipitation and dissolution chemical reactions corresponding to the stable solid phase, and the saturated solubility of the remaining metal elements in the primary water circuit can be obtained.

[0128] Here, taking the calculation of nickel ferrite solubility as an example, we briefly introduce the method of determining the chemical reaction of precipitation dissolution. According to the stable existence area of ​​nickel ferrite in the E-pH diagram at 558K, Figure 3 As shown, the lines around this stable zone represent the decomposition reactions of nickel ferrite, and the one involving dissolved substances is the precipitation-dissolution chemical reaction equation.

[0129] Figure 3Four dissolution reactions were identified at 558 K and are listed in Table 1.

[0130] Table 1 Chemical reaction equations of precipitation and dissolution of nickel ferrite at 558K

[0131] Serial number Precipitation-dissolution chemical reaction 1 <![CDATA[3NiFe 2 About 4 +6H + +H 2 =3Ni 2+ +2Fe 3 About 4 +4H 2 O]]> 2 <![CDATA[NiFe 2 SHE 4 +2H + =In 2+ +Feel 2 SHE 3 +H 2 You]]> 3 <h2 style=";text-align:left;direction:ltr"><![CDATA[3NiFe <h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> O<h2 style=";text-align:left;direction:ltr"> 4 <h2 style=";text-align:left;direction:ltr"> +5H<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> O+H<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> =3Ni(OH)<h2 style=";text-align:left;direction:ltr"> 3- <h2 style=";text-align:left;direction:ltr"> +2Fe<h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> O<h2 style=";text-align:left;direction:ltr"> 4 <h2 style=";text-align:left;direction:ltr"> +3H<h2 style=";text-align:left;direction:ltr"> + <h2 style=";text-align:left;direction:ltr"> ]]><h2 style=";text-align:left;direction:ltr"> 4 <![CDATA[NiFe 2 O 4 +2H 2 O=Ni(OH) 3- +Fe 2 O 3 +H + ]]>

[0132] When the temperature, pressure, DH, and DO concentrations change, the precipitation and dissolution chemical reactions of each stable solid phase will also change. In essence, the boundary lines of each solid phase in the E-pH diagram move.

[0133] After determining the precipitation-dissolution chemical reaction as described above, the ion concentrations corresponding to the remaining metal elements can be calculated based on the precipitation-dissolution chemical reaction and the Gibbs free energy corresponding to the precipitation-dissolution chemical reaction to satisfy formula (13):

[0134]

[0135] In formula (13), i represents different substances, C is a constant, X, T, Z, W and Y are coefficients, and the coefficients have different values ​​for different metals. H2 Indicates the partial pressure of hydrogen. ΔG T is the Gibbs free energy.

[0136] S12), constructing a first function based on the conservation of ionic charge, the ion product formula of boric acid and lithium hydroxide in primary water, and the concentrations of unionized boric acid and unionized lithium hydroxide, wherein the first function is used to characterize the corresponding relationship between the total concentration of lithium hydroxide and the pH value.

[0137] Among them, the calculation formula for ion charge conservation is shown in the following formula (iii):

[0138] [OH - ]+[∑B - ]=[Li + ]+[H + ]+[∑M + ] (iii)

[0139] The ionic product formula of water is shown in (iv) below:

[0140] K w =[H + ][OH - (iv)

[0141] The ion product formula of lithium hydroxide is shown in the above formula (9).

[0142] [∑B - The calculation formula (v) of ] can be obtained according to the ion product formula of boric acid:

[0143]

[0144] [∑M + ] can be calculated by the above solubility calculation formula. Under the condition of one loop, [∑M + ] can be ignored compared to other positive ions, so the first function satisfies formula (14):

[0145]

[0146] In formula (14), [LiOH] bulk Represents the current measured total concentration of lithium hydroxide, K w represents the ionic product of water, [H + ] indicates H + The molar concentration in the primary water circuit, K 1 B represents the primary ionization constant of boric acid; K 2 B represents the secondary ionization constant of boric acid; K 3 B represents the tertiary dissociation constant of boric acid, x represents the molar concentration of unionized boric acid, K j represents the ionic product of lithium hydroxide.

[0147] According to the above formula, [LiOH] bulk Calculate the current pH value.

[0148] S13), calculating the current pH value of the primary circuit water according to the first function and the currently measured total concentration of lithium hydroxide.

[0149] The current total concentration of lithium hydroxide can be measured, and thus the current pH value can be obtained.

[0150] In some embodiments, calculating the current pH value of the primary circuit water according to the first function and the current measured total concentration of lithium hydroxide includes:

[0151] According to the first function and the reference pH value of the primary water, the reference total concentration of lithium hydroxide corresponding to the reference pH value is calculated; the reference pH value is used as the initial value of pH iteration, and according to the current measured total concentration of lithium hydroxide, the first function and the iterative algorithm, the initial value of pH iteration is corrected i times until the absolute value of the difference between the current pH value and the i-th pH correction value is less than or equal to a preset threshold, wherein i is an integer greater than or equal to 1, and during the i-time correction process, the last pH correction value is used as the initial value of pH iteration for the next correction.

[0152] In these embodiments, by using the reference pH value as the initial value of the pH iteration and repeatedly correcting the initial value of the pH iteration through an iterative algorithm, the current pH value can be continuously approximated to the accuracy requirement, so that the accurate current pH value can be calculated.

[0153] In some embodiments, the above iterative algorithm satisfies the following formula (1):

[0154]

[0155] Wherein, in formula (1), pH represents the current pH value, and pH 0 represents the initial value of the pH iteration in each correction process, [LiOH] bulk represents the current measured total concentration of lithium hydroxide, [LiOH] 0 represents the initial total concentration of lithium hydroxide iteration in each correction process, [LiOH] 0 and pH 0 satisfy the first function, and n represents the preset threshold.

[0156] In these embodiments, before the iterative calculation, first calculate the reference total concentration of lithium hydroxide corresponding to the reference pH value according to the first function and the reference pH value of the primary coolant water, and then use the reference pH value as the initial value of the pH iteration pH 0 , and use the reference total concentration of lithium hydroxide as the initial total concentration of lithium hydroxide iteration [LiOH] 0 , and then combine with the currently measured total concentration of lithium hydroxide [LiOH] bulk measured to obtain the first pH correction value, use the first pH correction value as the initial value of the pH iteration for the second correction, and calculate the initial total concentration of lithium hydroxide iteration [LiOH] 0 corresponding to the first pH correction value according to the first pH correction value and the first function, repeat the above iteration until |pH - pH 0 | < n, and the iteration converges.

[0157] Wherein, the initial total concentration of lithium hydroxide iteration [LiOH] 0 can be obtained by substituting the initial value of the pH iteration after each correction into formula (14), that is, [LiOH] bulk calculated in formula (14) is the initial total concentration of lithium hydroxide iteration [LiOH] 0 corresponding to the initial value of the pH iteration.

[0158] Based on the above, n can be 0.0001. In this way, when |pH - pH 0 | < 0.001, the iteration converges. The current pH value can be approximated to the accuracy requirement to the greatest extent.

[0159] The embodiment of the present application provides a method for determining the chemistry of primary water, by obtaining the concentration of unionized boric acid and unionized lithium hydroxide in primary water at the current measurement temperature, and the saturated solubility of each metal element in primary water except lithium in primary water, and using the ion charge conservation, the ion product formula of boric acid and lithium hydroxide in primary water, and the concentration of unionized boric acid and unionized lithium hydroxide, to construct a functional relationship between the total concentration of lithium hydroxide and the pH value, and taking into account the possible reaction mechanism affecting the pH change in primary water when calculating the pH value, the calculation result is accurate, so that the influence of the pH change of primary water on the corrosion of steam generators can be accurately predicted, and then the reaction performance of fuel rods and the safety of reactors can be provided with an accurate reference. At the same time, by determining the saturated solubility of metal elements in primary water, the corrosion of alloy materials outside the reactor and the fouling behavior of fuel rods can also be predicted, so that the reaction performance of fuel rods and the safety of reactors can be further provided with a reference.

[0160] Some examples of the present application also provide a method for determining the water chemistry of a loop, in which the input parameters are set as follows: the boron concentration of the main fluid is 566ppm; the lithium hydroxide concentration of the main fluid is 1.42ppm; the dissolved hydrogen concentration is 30cc / kg; the main fluid temperature is 300°C, and the comparison between the current pH value and the reference pH value is obtained by calculation. Figure 4 As shown in Table 2 below, the saturation concentration of each metal ion at pH = 7.2 is given.

[0161] Table 2 Water chemistry calculation results

[0162] name value unit pH 7.2 / Ni saturation concentration 4.01e-10 / Fe saturation concentration 3.93e-09 / Cr saturation concentration 6.38e-11 / Co saturation concentration 5.10e-10 / Mn saturation concentration 3.39e-10 /

[0163] Depend on Figure 4 It can be seen that the current pH value calculated in the embodiment of the present application deviates slightly from the pH value of the reference example, and the determination coefficient R 2 It is 0.9176, indicating that the current pH value calculated in the embodiment of the present application is relatively accurate.

[0164] The present application also provides a device for determining the water chemistry of a circuit, such as Figure 5 As shown, including:

[0165] The acquisition module 501 is used to obtain the concentration of unionized boric acid and unionized lithium hydroxide in the primary water at the current measurement temperature, and the saturated solubility of the remaining metal elements in the primary water except lithium in the primary water; the construction module 502 is used to construct a first function based on the conservation of ionic charge, the ion product formula of boric acid and lithium hydroxide in the primary water, and the concentration saturation solubility of unionized boric acid and unionized lithium hydroxide, and the first function is used to characterize the corresponding relationship between the total concentration of lithium hydroxide and the pH value; the calculation module 503 is used to calculate the current pH value of the primary water based on the first function and the current measured total concentration of lithium hydroxide.

[0166] In some embodiments, Figure 5 As shown, the calculation module 503 is specifically used to calculate the reference total concentration of lithium hydroxide corresponding to the reference pH value according to the first function and the reference pH value of the first-circuit water; taking the reference pH value as the pH iteration initial value, and correcting the pH iteration initial value i times according to the current measured total concentration of lithium hydroxide, the first function and the iterative algorithm, until the absolute value of the difference between the current pH value and the corrected pH initial value is less than or equal to the preset threshold, wherein i is an integer greater than or equal to 1, and in the i-time correction process, the last pH correction value is used as the pH iteration initial value for the next correction.

[0167] In some embodiments, the acquisition module 501 is specifically used to calculate the concentration of unionized boric acid in the primary-loop water at the current measurement temperature according to the ion product formula of boric acid in the primary-loop water and the mass conservation law of boron element.

[0168] In some embodiments, the acquisition module 501 is further specifically configured to calculate the concentration of unionized lithium hydroxide according to the ion product formula of lithium hydroxide, the total concentration of lithium hydroxide, and the degree of ionization of lithium hydroxide at the current measurement temperature.

[0169] In some embodiments, the acquisition module 501 is also specifically used to obtain the Gibbs free energy of the precipitation-dissolution chemical reaction corresponding to the stable solid state of each metal element except lithium in the primary water at the current measurement temperature, and calculate the ion concentration corresponding to the remaining metal elements based on the precipitation-dissolution chemical reaction and Gibbs free energy; according to the type of element, the ion concentration corresponding to each of the remaining metal elements is accumulated respectively to obtain the saturated solubility of the remaining metal elements in the primary water.

[0170] The above module division is only a logical function division, and there may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Each functional module in each embodiment of the present application can be integrated into a processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. Figure 5 The above modules can be implemented in the form of hardware or software functional units. For example, when implemented in software, the acquisition module 501, the construction module 502, and the calculation module 503 can be implemented by software functional modules generated by at least one processor after reading the program code stored in the memory. Figure 5 The above modules can also be implemented by different hardware in the computer, for example, the acquisition module 501 is implemented by a part of the processing resources in at least one processor (for example, one core or two cores in a multi-core processor), while the construction module 502 and the calculation module 503 are implemented by the remaining processing resources in at least one processor (for example, other cores in a multi-core processor), or by programmable devices such as field-programmable gate arrays (FPGAs) or coprocessors. Obviously, the above functional modules can also be implemented in a combination of software and hardware, for example, the acquisition module 501 is implemented by a hardware programmable device, while the construction module 502 and the calculation module 503 are software functional modules generated by the CPU after reading the program code stored in the memory.

[0171] Figure 5 For more details on how the acquisition module 501, the construction module 502, and the calculation module 503 implement the above functions, please refer to the relevant descriptions in the previous embodiments, which will not be repeated here. The determination device also has the same technical effect as the determination method described above.

[0172] The present application also provides a computer device, such as Figure 6As shown, the computer device includes: a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a method for determining the water chemistry of a circuit is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a key, trackball or touchpad set on the computer device shell, or an external keyboard, touchpad or mouse, etc.

[0173] Those skilled in the art will appreciate that the structural description of the above-mentioned computer device is only a partial structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0174] In some embodiments, a computer device is also provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0175] The implementation principles and technical effects of each step implemented by the processor in this embodiment are similar to the principles of the above-mentioned method for determining the water chemistry of a single circuit, and will not be repeated here.

[0176] An embodiment of the present application further provides a computer storage medium, which stores computer program instructions. When the computer program instructions are executed on a computer, a processor executes the steps in the above-mentioned method embodiments.

[0177] The implementation principles and technical effects of the various steps implemented when the computer program is executed by the processor in this embodiment are similar to the principles of the above-mentioned method for determining the water chemistry of a single circuit, and will not be repeated here.

[0178] An embodiment of the present application further provides a computer program product, including a computer program, which implements the steps in the above-mentioned method embodiments when executed by a processor.

[0179] The implementation principles and technical effects of the steps implemented when the computer program in this embodiment is executed by the processor are similar to the principles of the above-mentioned method for determining the water chemistry of a single circuit, and will not be repeated here.

[0180] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0181] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium experimented in the embodiments provided in the present application can include at least one of non-volatile and volatile facilitating memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processors involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this. Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments.

[0182] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer program instructions. When the computer program instructions are loaded and executed on a computer, the process or function in accordance with the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable device. The computer program instructions can be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server, data center, etc. that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a magnetic disk, a tape), an optical medium (e.g., a digital video disc (digital video disc, DVD)), or a semiconductor medium (e.g., a solid state drive (solid state drives, SSD)), etc.

[0183] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0184] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for determining the water chemistry of a primary circuit, characterized in that: include: Obtaining the concentrations of unionized boric acid and unionized lithium hydroxide in the primary water at the current measurement temperature, and the saturated solubility of the remaining metal elements in the primary water except lithium in the primary water; According to the conservation of ionic charge, the ion product formula of boric acid and lithium hydroxide in the primary water, and the concentrations of the unionized boric acid and the unionized lithium hydroxide, a first function is constructed, wherein the first function is used to characterize the corresponding relationship between the total concentration of lithium hydroxide and the pH value; The current pH value of the primary circuit water is calculated based on the first function and the currently measured total concentration of the lithium hydroxide.

2. The method according to claim 1, characterized in that Calculating the current pH value of the primary circuit water according to the first function and the current measured total concentration of the lithium hydroxide includes: Calculating a reference total concentration of lithium hydroxide corresponding to the reference pH value according to the first function and the reference pH value of the primary circuit water; The reference pH value is used as the pH iteration initial value, and the pH iteration initial value is corrected i times according to the current measured total concentration of lithium hydroxide, the first function and the iterative algorithm until the absolute value of the difference between the current pH value and the i-th pH correction value is less than or equal to a preset threshold, wherein i is an integer greater than or equal to 1, and during the i-time correction process, the last pH correction value is used as the pH iteration initial value for the next correction.

3. The method according to claim 2, characterized in that The iterative algorithm satisfies the following formula (1): Wherein, in formula (1), pH represents the current pH value, pH0 represents the initial value of pH iteration in each calibration process, [LiOH] bulk represents the currently measured total concentration of lithium hydroxide, [LiOH]0 represents the iterative initial total concentration of lithium hydroxide in each calibration process, [LiOH]0 and pH0 satisfy the first function, and n represents the preset threshold value.

4. The method according to claim 1, characterized in that: Obtaining the concentration of unionized boric acid in the primary circuit water at the current measurement temperature, including: According to the ion product formula of the boric acid in the primary-loop water and the mass conservation of the boron element, the concentration of the unionized boric acid in the primary-loop water at the current measuring temperature is calculated.

5. The method according to claim 4, characterized in that The ion product formula of the boric acid in the primary water circuit satisfies formulas (2), (3), (4), (5), (6) and (7): Wherein, in formula (2), formula (3), formula (4), formula (5), formula (6) and formula (7), [B(OH) - 4] represents B(OH) - The molar concentration of 4, [OH - ] indicates OH in the primary water - The molar concentration of [B(OH)3] represents the molar concentration of unionized boric acid, and K 1 B represents the primary ionization constant of boric acid; [B2(OH) - 7] represents B2(OH) - 7 molar concentration, K 2 B represents the secondary ionization constant of boric acid; [B3(OH) - 10 ] indicates B3(OH) - 10 The molar concentration, K 3 B represents the tertiary ionization constant of boric acid, and T represents the current measurement temperature; The calculation formula of the concentration of the unionized boric acid satisfies formula (8): In formula (8), x represents the molar concentration of unionized boric acid, and [B] represents the total molar concentration of boric acid.

6. The method according to claim 1, characterized in that Obtaining the concentration of unionized lithium hydroxide in the primary circuit water at the current measurement temperature, including: The concentration of the unionized lithium hydroxide in the primary-loop water is calculated based on the ion product formula of the lithium hydroxide, the currently measured total concentration of the lithium hydroxide, and the degree of ionization of the lithium hydroxide at the currently measured temperature.

7. The method according to claim 6, characterized in that The ion product formula of the lithium hydroxide satisfies formulas (9) and (10): log K j =-0.8217-0.0031T (10) In formulas (9) and (10), K j represents the ionic product of lithium hydroxide, [Li + ] indicates Li + The molar concentration of [OH-] represents the molar concentration of OH- in the primary water circuit, [LiOH] represents the molar concentration of unionized lithium hydroxide, and T represents the current measurement temperature; The calculation formula for the concentration of the unionized lithium hydroxide satisfies formula (11): [LiOH]=[LiOH] bulk (1-α LiOH ) (11) In formula (11), [LiOH] bulk Represents the current measured total concentration of lithium hydroxide, α LiOH Indicates the current degree of ionization of lithium hydroxide.

8. The method according to claim 1, characterized in that Obtaining the saturated solubility of each metal element in the primary circuit water except lithium at the current measurement temperature, including: Obtaining the Gibbs free energy of the precipitation and dissolution chemical reaction corresponding to the stable solid phase of each metal element in the primary circuit water except the lithium element at the current measurement temperature; Calculating the ion concentrations corresponding to the remaining metal elements according to the precipitation dissolution chemical reaction and the Gibbs free energy; According to the element type, the ion concentration corresponding to each of the remaining metal elements is accumulated respectively to obtain the saturated solubility of the remaining metal elements in the primary circuit water.

9. The method according to claim 1, characterized in that: The first function satisfies formula (14): In formula (14), [LiOH] bulk Represents the current measured total concentration of lithium hydroxide, K w represents the ionic product of water, [H + ] indicates H + The molar concentration in the primary water circuit, K 1 B represents the primary ionization constant of boric acid; K 2 B represents the secondary ionization constant of boric acid; K 3 B represents the tertiary dissociation constant of boric acid, x represents the molar concentration of unionized boric acid, K j represents the ionic product of lithium hydroxide.

10. A device for determining the water chemistry of a circuit, characterized in that: include: An acquisition module, used to acquire the concentration of unionized boric acid and unionized lithium hydroxide in the primary water at a current measurement temperature, and the saturated solubility of other metal elements in the primary water except lithium in the primary water; A construction module is used to construct a first function based on the conservation of ionic charge, the ion product formula of boric acid and lithium hydroxide in the primary water, and the concentrations of the unionized boric acid and the unionized lithium hydroxide, wherein the first function is used to characterize the corresponding relationship between the total concentration of lithium hydroxide and the pH value; A calculation module is used to calculate the current pH value of the primary circuit water according to the first function and the currently measured total concentration of the lithium hydroxide.

11. A computer device, characterized in that: include: a processor and a memory configured to store computer program instructions; When the computer program instructions are executed by the processor, the computer is caused to perform the steps of the method according to any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed on a computer, a processor is enabled to execute the steps of the method according to any one of claims 1 to 9.

13. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of any one of the methods described in 1 to 9 are implemented.

Images