Heat and mass transfer analysis method and apparatus for corrosion product in nuclear reactor, and device

Abstract

A heat and mass transfer analysis method and apparatus for a corrosion product in a nuclear reactor, a computer device, a storage medium, and a computer program product. The heat and mass transfer analysis method for a corrosion product in a nuclear reactor comprises: acquiring the average thermal conductivity of a corrosion product, and on the basis of the average thermal conductivity, determining the temperature distributions of the corrosion product when a coolant is in a saturated state, a nucleate boiling state, and an evaporated state, respectively (S202); on the basis of the pressure distribution in the corrosion product, determining the flow velocity distribution of the coolant in the corrosion product (S204); acquiring a concentration relational expression between the concentration of boric acid and the concentration of another soluble substance in the coolant, and on the basis of the concentration relational expression and the concentration of boric acid, determining the concentration distribution of the another soluble substance (S206); and on the basis of the temperature distributions, the flow velocity distribution, and the concentration distribution of the soluble substance, analyzing heat and mass transfer inside the corrosion product to obtain the concentration of boron after enrichment inside the corrosion product, and on the basis of the concentration after enrichment, obtaining the total amount of boron deposition (S208).

Description

Heat and mass transfer analysis method, device and equipment for nuclear reactor corrosion products

[0001] Related applications

[0002] This application claims priority to Chinese patent application number 202311017699.8, filed on August 11, 2023, entitled “Methods, devices and equipment for heat and mass transfer analysis of nuclear reactor corrosion products,” the entire text of which is hereby incorporated by reference. Technical Field

[0003] The present application relates to the technical field of heat and mass transfer analysis, and in particular to a heat and mass transfer analysis method, apparatus, computer equipment, storage medium, and computer program product for nuclear reactor corrosion products. Background Art

[0004] During operation, pressurized water reactors (PWRs) form a large amount of oxidative corrosion products, primarily iron and nickel ions, and their oxides. These corrosion products, under the influence of subcooled nucleate boiling, deposit on the surface of the fuel cladding above the core, forming a thin, loose, and porous scaling layer known as corrosion products. The presence of these corrosion products increases the thermal resistance of the fuel rods, degrading heat transfer performance. Furthermore, the porous chimney structure causes boron to accumulate within these corrosion products, resulting in uneven axial distribution of boron along the fuel rods and, in turn, inducing core power drift.

[0005] At present, the heat and mass transfer processes inside corrosion products are mainly analyzed by calculating the temperature, flow rate, pressure and solute concentration distribution in the deposition layer. However, due to the small number of parameters, the accuracy of heat and mass transfer analysis will be reduced.

[0006] Summary of the Invention

[0007] Based on this, it is necessary to provide a heat and mass transfer analysis method, device, computer equipment, computer-readable storage medium and computer program product for nuclear reactor corrosion products that can accurately analyze heat and mass transfer in response to the above technical problems.

[0008] In a first aspect, the present application provides a method for analyzing heat and mass transfer of nuclear reactor corrosion products, the method comprising:

[0009] Obtaining an average thermal conductivity of corrosion products in the nuclear reactor, and determining, based on the average thermal conductivity, temperature distributions of the corrosion products when the coolant is in a saturated state, a nucleate boiling state, and an evaporated state;

[0010] determining a flow rate distribution of a coolant in the corrosion product based on a pressure distribution in the corrosion product;

[0011] Obtaining a concentration relationship between the concentration of boric acid and the concentration of other soluble substances in the coolant, and determining a concentration distribution of the other soluble substances based on the concentration relationship and the boric acid concentration;

[0012] Based on the temperature distribution, the flow velocity distribution, and the concentration distribution of soluble substances, the heat and mass transfer processes inside the corrosion product are analyzed to obtain the concentration of boron after enrichment inside the corrosion product, and the total amount of boron deposition is obtained based on the concentration after enrichment; the soluble substances include boric acid and other soluble substances.

[0013] In one embodiment, obtaining the average thermal conductivity of the corrosion products includes:

[0014] obtaining the porosity of the corrosion product, the solid thermal conductivity of the corrosion product, and the liquid thermal conductivity of the coolant in the corrosion product;

[0015] An average thermal conductivity of the corrosion product is determined based on the porosity, the solid thermal conductivity, and the liquid thermal conductivity.

[0016] In one embodiment, determining the temperature distribution of the corrosion product when the coolant is saturated based on the average thermal conductivity includes:

[0017] obtaining the thickness of the corrosion product;

[0018] Based on the average thermal conductivity and the thickness, a saturation temperature distribution of the corrosion product when the coolant is in a saturated state is determined; the temperature distribution includes a saturation temperature distribution.

[0019] In one embodiment, determining the temperature distribution inside the corrosion product when the coolant is in a nucleate boiling state based on the average thermal conductivity includes:

[0020] Obtaining a wick boiling relationship that characterizes the relationship between the thickness of the corrosion product and the temperature inside the corrosion product when the coolant is in a nucleate boiling state;

[0021] Based on the thickness distribution of the corrosion product and the wick boiling relationship, the temperature distribution inside the corrosion product in the nucleate boiling state is determined; the temperature distribution includes the temperature distribution in the nucleate boiling state.

[0022] In one embodiment, the method further comprises:

[0023] Determining a temperature relationship equation representing the relationship between the thickness of the corrosion product and the temperature of the corrosion product, a flow rate relationship equation representing the relationship between the pressure in the corrosion product and the flow rate of the coolant, and a concentration relationship equation;

[0024] Based on the temperature relationship and the thickness of the corrosion product, determining an nth temperature distribution of the corrosion product in the nth iteration step and an n+1th temperature distribution of the corrosion product in the n+1th iteration step, and determining a temperature difference between the nth temperature distribution and the n+1th temperature distribution; the nth iteration step and the n+1th iteration step are adjacent iteration steps; n is a positive integer;

[0025] determining, based on the flow velocity relationship and the pressure in the corrosion product, an nth flow velocity distribution of the coolant in the nth iteration step and an n+1th flow velocity distribution of the coolant in the n+1th iteration step, and determining a flow velocity difference between the nth flow velocity distribution and the n+1th flow velocity distribution;

[0026] Determining, based on the concentration relationship and the boric acid concentration in the coolant, an nth concentration distribution of the concentration of the other soluble substances in the nth iteration step and an n+1th concentration distribution of the coolant in the n+1th iteration step, and determining a concentration difference between the nth concentration distribution and the n+1th concentration distribution;

[0027] Determine a maximum difference among the temperature difference, the flow velocity difference, and the concentration difference, and when the maximum difference is less than a preset difference threshold, determine the nth flow velocity distribution as the flow velocity distribution, determine the nth temperature distribution as the temperature distribution, and determine the nth concentration distribution as the concentration distribution of the other soluble substances.

[0028] In one embodiment, determining the temperature distribution of the corrosion product when the coolant is in an evaporated state based on the average thermal conductivity includes:

[0029] Obtaining a three-dimensional coordinate system relationship equation representing the relationship between the thickness of the corrosion product and the temperature of the corrosion product when the coolant is evaporated to dryness;

[0030] Based on the relationship between the thickness of the corrosion product and the three-dimensional coordinate system, the evaporation temperature distribution of the corrosion product is determined; the temperature distribution includes the evaporation temperature distribution.

[0031] In a second aspect, the present application provides a heat and mass transfer analysis device for nuclear reactor corrosion products, the device comprising:

[0032] a temperature distribution determination module, which obtains an average thermal conductivity of corrosion products of the nuclear reactor and determines, based on the average thermal conductivity, a temperature distribution of the corrosion products when the coolant is in a saturated state, a nucleate boiling state, and an evaporated state;

[0033] a flow rate distribution determining module, which determines a flow rate distribution of a coolant in the corrosion product based on a pressure distribution in the corrosion product;

[0034] a concentration distribution determining module, which obtains a concentration relationship between the concentration of boric acid and the concentration of other soluble substances in the coolant, and determines the concentration distribution of the other soluble substances based on the concentration relationship and the boric acid concentration;

[0035] An analysis module analyzes the heat and mass transfer process of the corrosion product based on the temperature distribution, the flow velocity distribution, and the concentration distribution of soluble substances, obtains the concentration of boron after enrichment in the corrosion product, and obtains the total amount of boron deposition based on the enriched concentration; the soluble substances include boric acid and other soluble substances.

[0036] In a third aspect, the present application provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0037] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the above method when executed by a processor.

[0038] In a fifth aspect, the present application provides a computer program product, comprising a computer program, which implements the steps of the above method when executed by a processor.

[0039] The heat and mass transfer analysis method, apparatus, computer equipment, storage medium, and computer program product for nuclear reactor corrosion products analyze the temperature distribution of the corrosion products based on their average thermal conductivity when the coolant is in a saturated state, a nucleate boiling state, and an evaporated state, thereby determining the effect of the coolant state on the heat transfer of the corrosion products and performing a comprehensive analysis of the heat transfer of the corrosion products. The method also determines the coolant flow rate distribution based on the pressure distribution in the corrosion products, determines the concentration of other soluble substances in the corrosion products based on a concentration relationship and the boric acid concentration in the corrosion products, and performs a heat and mass transfer analysis in combination with the temperature distribution, flow rate distribution, and concentration distribution of the soluble substances. The coupled relationship among the temperature distribution, flow rate distribution, and concentration distribution of the soluble substances can be taken into account, thereby achieving a comprehensive analysis of the heat and mass transfer process, obtaining a relatively accurate concentration of boron after internal enrichment in the corrosion products, and thus obtaining the total amount of boron deposition. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG1 is a diagram illustrating an application environment of a heat and mass transfer analysis method for nuclear reactor corrosion products according to an embodiment;

[0041] FIG2 is a schematic flow diagram of a method for analyzing heat and mass transfer of nuclear reactor corrosion products according to one embodiment;

[0042] FIG3 is a schematic flow diagram of a method for analyzing heat and mass transfer of nuclear reactor corrosion products according to another embodiment;

[0043] FIG4 is a block diagram of a heat and mass transfer analysis device for nuclear reactor corrosion products according to one embodiment;

[0044] FIG5 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0046] The heat and mass transfer analysis method for nuclear reactor corrosion products provided in an embodiment of the present application can be applied in the application environment shown in FIG1 . Terminal 102 communicates with server 104 via a network. A data storage system can store data that server 104 needs to process. The data storage system can be integrated with server 104, or located in the cloud or on another network server. Server 104 obtains the average thermal conductivity of the corrosion products in the nuclear reactor and, based on the average thermal conductivity, determines the temperature distribution of the corrosion products when the coolant is in a saturated state, a nucleate boiling state, and an evaporated state. Based on the pressure distribution within the corrosion products, server 104 determines the coolant flow rate distribution within the corrosion products. Server 104 obtains a concentration equation representing the relationship between the boric acid concentration and the concentration of other soluble substances in the coolant. Then, based on the concentration equation and the boric acid concentration, it determines the concentration distribution of the other soluble substances. Based on the obtained temperature distribution, flow rate distribution, soluble substance concentration distribution, and the total amount of boron deposited in the corrosion products, server 104 analyzes the heat and mass transfer within the corrosion products to obtain analysis results. The terminal 102 may be, but is not limited to, various personal computers, laptops, tablet computers, IoT devices, etc. The server 104 may be implemented as an independent server or a server cluster consisting of multiple servers.

[0047] In one embodiment, as shown in FIG2 , a heat and mass transfer analysis method for nuclear reactor corrosion products is provided. The method is described using the server 104 in FIG1 as an example, and includes the following steps:

[0048] Step 202: Obtain an average thermal conductivity of the corrosion products in the nuclear reactor, and determine the temperature distribution of the corrosion products when the coolant is in a saturated state, a nucleate boiling state, and an evaporated state, respectively, based on the average thermal conductivity.

[0049] Corrosion products are primarily oxidative corrosion products of iron and nickel ions and their oxides that deposit on the fuel cladding surface under the action of supercooled nucleate boiling, forming a thin, loose, and porous fouling layer. For example, CRUD (chalk river unidentified deposit) is a layer of oxidative corrosion product deposited on the fuel cladding surface.

[0050] Average thermal conductivity, also known as thermal conductivity, is the inherent ability to transfer or conduct heat. It is derived from the solid thermal conductivity of corrosion products and the fluid thermal conductivity of coolants. Temperature distribution refers to the variation in temperature within a region at a given time as a function of spatial position. For example, at the current time, within region A, there are positions a and b. The temperature at position a is x, and the temperature at position b is y. By combining the temperatures of these two positions, we can determine the temperature distribution of region A at the current time.

[0051] Saturation occurs when the number of molecules entering the liquid space per unit time is equal to the number returning to the liquid, and evaporation and condensation are in dynamic equilibrium. While evaporation and condensation continue, the density of vapor molecules in the space no longer increases. This state is called saturation. When the coolant is saturated, the porous areas of corrosion products are filled with liquid. Heat transferred from the cladding surface to the fuel rods is transferred to the coolant through the corrosion products by heat conduction. Temperature analysis under saturation allows for early prediction of temperature distribution and avoids localized overheating that can lead to fuel damage. Nucleate boiling occurs when superheat increases, bubbles continuously form on the walls, rise, and grow in the liquid. As heat transfer progresses, when the CRUD-cladding interface temperature reaches the nucleate boiling initiation temperature, nucleate boiling begins at the bottom of the CRUD layer, filling the CRUD with coolant and vapor. The coolant fills the small pore areas, while the vapor fills the large pore areas, known as the chimney area. Coolant and steam flow along a low-resistance path. Capillary forces draw coolant to the bottom of the CRUD, where it contacts the fuel cladding, where bubbles form and further transform into steam. The steam escapes through the chimney into the coolant and is subsequently carried away by the coolant flow. Nucleate boiling heat transfer enhances heat transfer within the CRUD, significantly increasing the overall heat transfer coefficient between the fuel rods and the coolant. The boil-off state occurs when the coolant required for nucleate boiling exceeds the coolant provided by capillary forces, disrupting the liquid-gas separation in the steam chimney. In this case, the coolant dries at the interface between the corrosion product and the cladding, forming a gas film that reduces the overall heat transfer coefficient of the CRUD.

[0052] Optionally, the server first determines the average thermal conductivity of the corrosion products based on the solid thermal conductivity of the corrosion products and the fluid thermal conductivity of the coolant, and then determines the temperature distribution of the corrosion products when the coolant is in a saturated state according to the average thermal conductivity, determines the temperature distribution of the corrosion products when the coolant is in a nucleate boiling state according to the average thermal conductivity, and determines the temperature distribution of the corrosion products when the coolant is in an evaporated state according to the average thermal conductivity.

[0053] Step 204 : Determine the flow rate distribution of the coolant in the corrosion product based on the pressure distribution in the corrosion product.

[0054] The pressure distribution is derived from the pressure governing equation and its boundary conditions. The flow velocity distribution is obtained by solving the relationship between pressure and flow velocity, as determined by Darcy's law, based on the obtained pressure distribution. This means that the pressure distribution serves as the independent variable in the relationship, the flow velocity distribution serves as the dependent variable, and other parameters are known. The flow velocity distribution of the coolant at each location within the corrosion product can be derived. The pressure distribution refers to the set of specific pressure values ​​at each location within the corrosion product of a nuclear reactor. For example, at the current time point, there are locations a and b in region A, with the pressure at location a being x and the pressure at location b being y. Combining the pressures at these two locations yields the pressure distribution of region A at the current time point. The flow velocity distribution refers to the set of specific coolant flow velocity values ​​at each location within the corrosion product of a nuclear reactor. At different time points, the pressure or flow velocity at the same location may be the same or different.

[0055] The pressure control equation is The boundary conditions for the pressure control equation are: p| x＝0 =p f and Among them, ρ w Indicates the density of the coolant in kg / m 3 ;κ represents the permeability of corrosion products, i.e., CRUD permeability; μ w Indicates the dynamic viscosity of the coolant, in N·s / m 2 ;p f Indicates the coolant mainstream pressure in MPa; p and All represent the pressure inside the corrosion product; φ represents the porosity of the corrosion product; T represents the temperature of the corrosion product, T is a variable; r c represents the average pore radius, r represents the pore radius, which is a variable; x represents the depth of a certain position in the corrosion product; δ c represents the average thickness of CRUD in the deposition area; h fg It represents the latent heat of vaporization of the coolant, in kJ / mol.

[0056] The magnitude of CRUD penetration rate κ is mainly determined by the nth fractal dimension D f and the n+1th fractal dimension D T Sure:

[0057] where d E Indicates the effective hydraulic diameter in μm; λ min and λ max They represent the minimum and maximum pore diameters, respectively, in μm; φ represents the porosity of the corrosion product; L represents the thickness of the coolant bubble growth; and τ represents the tortuosity of the coolant flowing through the CRUD surface.

[0058] According to Darcy's law, the flow rate of coolant in the corrosion product and pressure The relationship expression is: Upcoming Pressure Substitute it as the independent variable into the relational expression to solve for the flow rate.

[0059] Optionally, the server determines an expression characterizing the relationship between pressure and flow rate based on Darcy's law, then solves the pressure distribution of the coolant in the corrosion product according to the pressure control equation and the boundary conditions for the pressure control equation, and finally determines the flow rate distribution of the coolant in the corrosion product according to the pressure distribution and the relationship expression between flow rate and pressure.

[0060] Step 206 : Obtain a concentration relationship expression characterizing the soluble substances in the coolant, and determine the concentration distribution of other soluble substances based on the concentration relationship expression and the boric acid concentration.

[0061] The concentration of boric acid in the coolant is obtained by explicitly solving the kinetic equation. The concentration of other soluble substances refers to the concentration of soluble substances in the coolant other than boric acid. The concentration of other soluble substances can be obtained by using the boric acid concentration and ordinary differential equations or algebraic calculations. The concentration distribution of soluble substances refers to the collection of specific values ​​of the concentration of soluble substances in the coolant at various locations in the nuclear reactor. The concentration calculation formula for each soluble substance is: Among them, C i Indicates the concentration of the i-th soluble substance, in mol / L; C i,source Refers to the concentration of the i-th soluble substance, C i,sink is the sedimentation concentration of the i-th soluble substance, in mol / L; D i It is expressed as the diffusion coefficient of the i-th soluble species related to the coolant temperature; τ represents the tortuosity of the coolant flowing through the CRUD surface; Indicates the vector depth of a certain position in CRUD; Represents the vector flow rate of the coolant at a certain position in the CRUD. The boundary conditions for the calculation formula of the concentration of other soluble substances are Among them, C i,coolant is the saturation concentration of the i-th soluble substance in the coolant, and x represents the depth of a certain position in the CRUD.

[0062] Optionally, the server calculates the concentration of the other soluble substances in the corrosion product based on the boric acid concentration in the corrosion product obtained by explicitly solving the kinetic equation and a concentration relationship formula representing the relationship between the boric acid concentration and the concentration of other soluble substances in the coolant. Based on the concentration relationship formula and the boric acid concentration, the server calculates the concentration of the other soluble substances in the corrosion product, thereby obtaining a concentration distribution of the other soluble substances in the coolant.

[0063] In step 208, the heat and mass transfer processes within the corrosion product are analyzed based on the temperature distribution, flow velocity distribution, and soluble substance concentration distribution to determine the concentration of boron after enrichment within the corrosion product. The total amount of boron deposition is then determined based on the enriched concentration. Soluble substances include boric acid and other soluble substances.

[0064] Among them, heat transfer and mass transfer refer to heat transfer and mass transfer respectively. B It can be calculated by using the total mass of the corrosion products and the concentration of boron after internal enrichment of the corrosion products. The calculation formula is: m B =C adsorp ρ c A d δ c , C adsorp Indicates the adsorption capacity of unit mass of corrosion products for boron, in g / g; ρ c Indicates the density of the coolant in kg / m 3 ; δ c Represents the average thickness of CRUD in the deposition area. adsorp The calculation formula is C adsorp =9×10 -9 ·C clad +2×10 -4 , C clad Indicates the concentration of boron after enrichment in the corrosion product, in ppm, C clad The calculation formula is Where CF represents the concentration factor, which is a dimensionless number; m e represents the boiling rate, obtained from thermal engineering software; C bulk Indicates the concentration of boric acid in the coolant in ppm; D B represents the diffusion coefficient of boron, in cm / s; ρ s Indicates the density of the coolant in a saturated state, in g / cm 3; φ represents the porosity of corrosion products. clad The calculation formula It can be seen that only when corrosion products exist and occur in the supercooled nucleate boiling region will concentration enrichment occur. In the concentration enriched region, the concentration distribution of corrosion products along the thickness direction is exponential. With the increase of thickness, C clad As the flow rate increases, the concentration difference between the bottom of the corrosion product and the main stream increases.

[0065] Optionally, the server analyzes the heat and mass transfer process of the corrosion product based on the obtained temperature distribution in the corrosion product, the flow rate distribution of the coolant, and the concentration distribution of soluble substances in the coolant, obtains the concentration of boron after enrichment inside the corrosion product, and obtains the total amount of boron deposition in the heat and mass transfer process inside the corrosion product based on the concentration of boron after enrichment inside the corrosion product.

[0066] In the above-mentioned heat and mass transfer analysis method of nuclear reactor corrosion products, the temperature distribution of the corrosion products is analyzed based on the average thermal conductivity of the corrosion products when the coolant is in a saturated state, a nucleate boiling state, and an evaporated state, thereby obtaining the influence of the coolant state on the heat transfer of the corrosion products, thereby enabling a comprehensive analysis of the heat transfer of the corrosion products. By determining the coolant flow rate distribution based on the pressure distribution in the corrosion products, determining the concentration of other soluble substances in the corrosion products based on the concentration relationship and the boric acid concentration in the corrosion products, and combining the temperature distribution, flow rate distribution, and the concentration distribution of the soluble substances for heat and mass transfer analysis, the coupling relationship among the temperature distribution, flow rate distribution, and the concentration distribution of the soluble substances can be taken into account, thereby achieving a comprehensive analysis of the heat and mass transfer process, obtaining a relatively accurate concentration of boron after internal enrichment in the corrosion products, and thereby obtaining the total amount of boron deposition.

[0067] In one embodiment, obtaining the average thermal conductivity of the corrosion products includes:

[0068] The porosity of the corrosion products, the solid thermal conductivity of the corrosion products, and the liquid thermal conductivity of the coolant in the corrosion products are obtained.

[0069] The average thermal conductivity of the corrosion products is determined based on the porosity, solid thermal conductivity, and liquid thermal conductivity.

[0070] Porosity refers to the percentage of the pore volume in a bulk material to the total volume of the material in its natural state. For example, the porosity of CRUD. Thermal conductivity, also known as thermal conductivity, reflects the heat conduction capacity of a material. According to Fourier's law, it is defined as the amount of heat transferred per unit temperature gradient per unit time through a unit heat conducting surface. The average thermal conductivity k m The calculation formula is k m =(1-φ)k s+φk f , where φ represents the porosity; k s is the thermal conductivity of the solid; k f k is the thermal conductivity of the liquid. s The solution can be obtained from the relationship between the proportion of each substance in the coolant and the temperature: k s,i is the thermal conductivity of the i-th substance in Table 1, v f,i is the volume fraction of the i-th substance in Table 1, and n is the number of substances. f The solution formula is: f =0.686+7.3*10 -10 P+5.87*10 -6 (Ts-415) 2 , P represents pressure, the unit is Pa; Ts represents coolant saturation temperature, the unit is K.

[0071] Table 1 Heat transfer coefficients and proportions of various material components

[0072] Optionally, the server obtains the fluid thermal conductivity of the coolant based on the relationship between the proportion of each substance in the coolant and the temperature, obtains the solid thermal conductivity of the corrosion product based on the solution formula of the solid thermal conductivity, and also obtains the porosity of the corrosion product. Based on the solid thermal conductivity, fluid thermal conductivity and porosity, the server uses the formula k m =(1-φ)k s +φk f The average thermal conductivity of the corrosion products is obtained by solving.

[0073] In this embodiment, the porosity, solid thermal conductivity, and fluid thermal conductivity are obtained, so that the average thermal conductivity of the corrosion products can be solved, and the temperature distribution of the corrosion products can be determined based on the average thermal conductivity.

[0074] In one embodiment, determining the temperature distribution inside the corrosion product when the coolant is saturated based on the average thermal conductivity includes:

[0075] Get the thickness of corrosion products.

[0076] The saturation temperature distribution of the corrosion products when the coolant is saturated is determined based on the average thermal conductivity and thickness; the temperature distribution includes the saturation temperature distribution.

[0077] Thickness refers to the thickness of the material under stable heat transfer conditions. For example, if the thickness of the CRUD is 1 meter under coolant saturation, then 1 meter is the thickness.

[0078] The saturation temperature distribution is determined based on the product of thickness and average thermal conductivity, that is, the saturation temperature distribution of the corrosion product when the coolant is saturated is obtained by multiplying the thickness of the corrosion product by the average thermal conductivity.

[0079] Optionally, the server obtains the thickness of the corrosion product, and then determines the saturation temperature distribution of the corrosion product when the coolant is in a saturated state based on a product result between the thickness and the average thermal conductivity.

[0080] In this embodiment, by analyzing heat transfer when the coolant is in a saturated state, the temperature distribution of corrosion products at a future time can be predicted in advance, thereby avoiding local excessive temperature that may cause fuel damage in the nuclear reactor.

[0081] In one embodiment, determining the temperature distribution of corrosion products when the coolant is in a nucleate boiling state based on the average thermal conductivity includes:

[0082] A wick boiling relationship is obtained, which characterizes the relationship between the thickness of the corrosion product and the temperature inside the corrosion product when the coolant is in a nucleate boiling state.

[0083] Based on the relationship between the thickness distribution of corrosion products and wick boiling, the temperature distribution inside the corrosion products in the nucleate boiling state is determined. The temperature distribution includes the temperature distribution in the nucleate boiling state.

[0084] Among them, the specific form of the wick boiling relationship is: The wick boiling relationship can be obtained by combining the heat transfer process formula ∫ shell q c dA+∫ chimney q b dA=0, the relationship between the CRUD internal temperature Tx and the CRUD thickness x: And the boundary conditions: T x＝0 =T0, Ts and T0 represent the coolant saturation temperature and the main fluid temperature, respectively, in K; x represents the depth of a certain position in the CRUD, in μm; Tx represents the temperature at the position with a depth of x in the CRUD, and N represents the pore density, in cells / cm 2 ; r c represents the average pore radius, in cm; f represents the CRUD effective heat transfer area coefficient, k m represents the average thermal conductivity of CRUD, in W / (m·K); q b Indicates boiling heat flux density in W / m 2 ;q c Refers to the heat flux density in CRUD A represents the evaporation coefficient; δ crepresents the average thickness of CRUD in the deposition area, in cm; chimney refers to the chimney channel in the corrosion product; shell refers to the integral along the entire cladding surface; h c represents the evaporation heat transfer coefficient;

[0085] Alternatively, the server can simultaneously calculate the heat transfer equation, the relationship between the CRUD internal temperature Tx and the CRUD thickness x, and the boundary conditions to obtain a wick boiling equation that characterizes the relationship between the thickness and temperature of the corrosion product when the coolant is in a nucleate boiling state. Based on the thickness of each location within the corrosion product and the obtained wick boiling equation, the server obtains a nucleate boiling temperature distribution representing the temperature at each location within the corrosion product.

[0086] In this embodiment, by obtaining the wick boiling relationship that characterizes the relationship between the thickness of the corrosion product and the temperature inside the corrosion product when the coolant is in the nucleate boiling state, the temperature distribution inside the corrosion product can be solved based on the wick boiling relationship and the thickness distribution of the corrosion product, thereby obtaining the temperature distribution of the corrosion product when the coolant is in the nucleate boiling state.

[0087] In one embodiment, as shown in FIG3 , a heat and mass transfer analysis method for nuclear reactor corrosion products includes:

[0088] Step 302: Determine a temperature relationship equation representing the relationship between the thickness of the corrosion product and the temperature of the corrosion product, a flow rate relationship equation representing the relationship between the pressure in the corrosion product and the flow rate of the coolant, and a concentration relationship equation.

[0089] The temperature relationship refers to the temperature relationship of the coolant in the saturated state, the nucleate boiling state, and the evaporated state. The flow rate relationship is the flow rate of the coolant in the corrosion product obtained according to Darcy's law. and pressure The relationship expression between The concentration relationship formula refers to the concentration calculation formula of soluble substances

[0090] Optionally, the server determines a temperature relationship expression for the coolant in three states: a saturated state, a nucleate boiling state, and an evaporated state. At the same time, based on Darcy's law, the server determines a relationship expression characterizing the relationship between the flow rate and pressure of the coolant in the corrosion product, and determines a concentration relationship expression characterizing the relationship between the concentration of boric acid in the coolant and the concentration of other soluble substances.

[0091] Step 304: Based on the temperature relationship and the thickness of the corrosion product, determine the nth temperature distribution of the corrosion product at the nth iteration step and the n+1th temperature distribution of the corrosion product at the n+1th iteration step, and determine the temperature difference between the nth temperature distribution and the n+1th temperature distribution. The nth iteration step and the n+1th iteration step are adjacent iteration steps. n is a positive integer.

[0092] Iteration refers to the repeated feedback process. The nth iteration step can be understood as the repeated feedback process at time A, and the n+1th iteration step can be understood as the repeated feedback process at time B. Time A and time B are adjacent, meaning there are no other iteration steps between the nth iteration step and the n+1th iteration step. When calculating the temperature distribution, the temperature calculated in the previous iteration step is used for the calculation in the next iteration step.

[0093] When the temperature difference between the nth temperature distribution obtained in the nth iteration step and the temperature distribution obtained in the n+1th iteration step is less than a preset difference threshold, it means that the temperature relationship has converged. The converged relationship can be used to calculate the n+2th temperature distribution in the n+2th iteration step again, or the nth temperature distribution or the n+1th temperature distribution can be directly output as the final temperature distribution for analyzing the heat and mass transfer process of the corrosion products.

[0094] Optionally, the server calculates the nth temperature distribution of the corrosion product in the nth iteration step and the n+1th temperature distribution of the corrosion product in the n+1th iteration step according to a relationship formula for calculating the temperature distribution of the coolant in a saturated state, calculates the nth temperature distribution of the corrosion product in the nth iteration step and the n+1th temperature distribution of the corrosion product in the n+1th iteration step according to a relationship formula for calculating the temperature distribution of the coolant in a nucleate boiling state, calculates the nth temperature distribution of the corrosion product in the nth iteration step and the n+1th temperature distribution of the corrosion product in the n+1th iteration step according to a relationship formula for calculating the temperature distribution of the coolant in a evaporated state, and then calculates the temperature difference based on the nth temperature distribution and the n+1th temperature distribution obtained when the coolant is in a saturated state, calculates the temperature difference based on the nth temperature distribution and the n+1th temperature distribution obtained when the coolant is in a nucleate boiling state, and calculates the temperature difference based on the nth temperature distribution and the n+1th temperature distribution obtained when the coolant is evaporated.

[0095] Step 306 , based on the flow rate relationship and the pressure in the corrosion product, determine the nth flow rate distribution of the coolant in the nth iteration step and the n+1th flow rate distribution of the coolant in the n+1th iteration step, and determine the flow rate difference between the nth flow rate distribution and the n+1th flow rate distribution.

[0096] Among them, the nth velocity distribution and the n+1th velocity distribution are based on the velocity relationship The specific values ​​of the pressure distribution are obtained. In other words, when the parameters on the right side of the velocity relationship equation are known, the coolant velocity distribution can be obtained. The specific values ​​of the velocity distribution used in each iteration may be the same or different. When calculating the velocity distribution, the velocity calculated in the previous iteration is used for the calculation in the next iteration.

[0097] Optionally, the server calculates an nth flow velocity distribution of the coolant at the nth iteration step and an n+1th flow velocity distribution at the n+1th iteration step based on a flow velocity expression representing the relationship between flow velocity and pressure, and the pressure distribution at the nth iteration step and the pressure distribution at the n+1th iteration step. The server calculates a flow velocity difference of the coolant based on the obtained nth flow velocity distribution and the obtained n+1th flow velocity distribution.

[0098] Step 308, based on the concentration relationship and the boric acid concentration in the coolant, determine the concentration of other soluble substances in the nth concentration distribution in the nth iteration step, and the n+1th concentration distribution of the coolant in the n+1th iteration step, and determine the concentration difference between the nth concentration distribution and the n+1th concentration distribution.

[0099] The concentration relationship is

[0100] Optionally, the server calculates an nth concentration distribution in the coolant at the nth iteration step and an n+1th concentration distribution at the n+1th iteration step based on a concentration expression representing the relationship between the boric acid concentration and the concentration of other soluble chemical substances, as well as the boric acid concentration distribution at the nth iteration step and the boric acid concentration distribution at the n+1th iteration step. The server calculates concentration differences for other soluble chemical substances in the coolant based on the obtained nth concentration distribution and n+1th concentration distribution.

[0101] Step 310, determine the maximum difference among the temperature difference, flow rate difference and concentration difference, and when the maximum difference is less than the preset difference threshold, determine the nth flow rate distribution as the flow rate distribution, determine the nth temperature distribution as the temperature distribution, and determine the nth concentration distribution as the concentration distribution of other soluble substances.

[0102] Optionally, the maximum difference refers to the category with the largest temperature difference, flow rate difference, and concentration difference. The maximum difference being less than a preset difference threshold indicates that all types of relationship expressions have converged. When the maximum difference is less than a preset difference threshold, the n+1th flow rate distribution can also be determined as the flow rate distribution for heat and mass transfer analysis, the n+1th temperature distribution can be determined as the temperature distribution for heat and mass transfer analysis, and the n+1th concentration distribution can be determined as the concentration distribution of other soluble substances for heat and mass transfer analysis. The n+2th temperature distribution, the n+2th flow rate distribution, and the n+2th concentration distribution of the n+2th iteration step can also be calculated based on the various types of converged relationship expressions.

[0103] In one embodiment, a temperature difference threshold value can be set for the temperature distribution, a flow velocity difference threshold value can be set for the flow velocity distribution, and a concentration difference threshold value can be set for the concentration distribution. It is set that only when the temperature difference is less than the temperature difference threshold value, the flow velocity difference is less than the flow velocity difference threshold value, and the concentration difference is less than the concentration difference threshold value, no iteration is required. That is to say, when all the relationship expressions are converged, the final determined relationship expression is used to determine the temperature distribution, flow velocity distribution, and concentration distribution for heat and mass transfer analysis of corrosion products.

[0104] In this embodiment, by setting a difference threshold and determining the convergence of each relationship only when the maximum difference is less than the preset difference threshold, the temperature distribution, concentration distribution, and flow rate distribution obtained based on each relationship can be made more accurate, thereby making the heat and mass transfer analysis results based on the temperature distribution, concentration distribution, and flow rate distribution more accurate.

[0105] In one embodiment, determining the temperature distribution of the corrosion products when the coolant is in an evaporated state by the average thermal conductivity includes:

[0106] A three-dimensional coordinate system relationship equation is obtained that characterizes the relationship between the thickness of the corrosion product and the temperature of the corrosion product when the coolant is evaporated to dryness.

[0107] Based on the relationship between the thickness of the corrosion product and the three-dimensional coordinate system, the evaporation temperature distribution of the corrosion product is determined. The temperature distribution includes the evaporation temperature distribution.

[0108] Among them, the three-dimensional coordinate system is mainly a coordinate system for positioning in three dimensions, which can be established through three-dimensional CFD (Computational Fluid Dynamics) software. For example, the cylindrical coordinate system, the geodetic coordinate system, the spherical coordinate system, etc. The specific form of the cylindrical coordinate system is: In the case of steady state, constant physical properties, and no internal heat source, the cylindrical coordinate system relationship can be rewritten as: The boundary conditions are where R c It represents the distance from the center of the chimney in the corrosion product to the unit boundary, in μm; C p,f Represents the specific heat of the coolant at the corresponding pressure; ρ f Indicates the density of the coolant; h c represents the evaporation heat transfer coefficient; T and Ts both represent temperature; q w It represents the heat flux density on the contact surface between the fuel cladding and the corrosion products, in W / m 2 ;k w Indicates the thickness of the thermal boundary layer, in W / (m·K); L b Indicates the thickness of bubble growth, in μm; represents the angle, Φ is an unknown parameter; r represents the pore radius.

[0109] Optionally, the server obtains a cylindrical coordinate system relationship that characterizes the relationship between the thickness of the corrosion product and the temperature of the corrosion product when the coolant is evaporated to dryness: And rewrite it under steady state, constant physical properties, and no internal heat source to get The server is based on the rewritten Solve the evaporation temperature distribution of corrosion products in three-dimensional conditions and solve the evaporation temperature distribution while meeting the boundary conditions.

[0110] In this embodiment, by determining a three-dimensional coordinate system relationship that characterizes the relationship between the thickness of the corrosion product and the temperature of the corrosion product when the coolant is in an evaporated state, the temperature distribution within the corrosion product can be observed more intuitively, thereby making the heat and mass transfer analysis results obtained based on the temperature distribution more accurate.

[0111] The present application also provides an application scenario that applies the above-mentioned heat and mass transfer analysis method for nuclear reactor corrosion products. Specifically, the application of the heat and mass transfer analysis method for nuclear reactor corrosion products in this application scenario is as follows: the server obtains the fluid thermal conductivity of the coolant based on the relationship between the proportion of each substance in the coolant and the temperature, obtains the solid thermal conductivity in the corrosion product based on the solution formula for solid thermal conductivity, and also obtains the porosity of the corrosion product. Based on the solid thermal conductivity, fluid thermal conductivity, and porosity, the server uses a formula to solve the average thermal conductivity of the corrosion product, and then determines the temperature distribution of the corrosion product when the coolant is saturated based on the product of the average thermal conductivity and the thickness of the corrosion product.

[0112] The server calculates the nth temperature distribution of the corrosion product at the nth iteration step and the n+1th temperature distribution of the corrosion product at the nth iteration step based on the equation for calculating the temperature distribution of the coolant under nucleate boiling conditions. It also calculates the nth temperature distribution of the corrosion product at the nth iteration step and the n+1th temperature distribution of the corrosion product at the n+1th iteration step based on the equation for calculating the temperature distribution of the coolant under evaporated conditions. It then calculates the temperature difference between the nth and n+1th temperature distributions obtained under saturated coolant conditions, the nth and n+1th temperature distributions obtained under nucleate boiling conditions, and the nth and n+1th temperature distributions obtained under evaporated coolant conditions. If all temperature differences are less than a temperature difference threshold, the server determines that the equation for calculating the temperature distribution has converged and determines the n+1th temperature distribution as the temperature distribution for heat and mass transfer analysis.

[0113] The server calculates the nth flow velocity distribution of the coolant at the nth iteration step and the n+1th flow velocity distribution at the n+1th iteration step, respectively, based on the flow velocity expression representing the relationship between flow velocity and pressure, as well as the pressure distribution at the nth iteration step and the pressure distribution at the n+1th iteration step. Based on the obtained nth flow velocity distribution and the n+1th flow velocity distribution, the server calculates a flow velocity difference for the coolant. If both flow velocity differences are less than a flow velocity difference threshold, the server determines that the relationship for calculating the flow velocity distribution has converged and determines the n+1th flow velocity distribution as the flow velocity distribution for use in heat and mass transfer analysis.

[0114] Based on the concentration expression representing the relationship between the boric acid concentration and the concentration of other soluble substances, as well as the boric acid concentration distribution at the nth iteration step and the boric acid concentration distribution at the n+1th iteration step, the server calculates the nth concentration distribution in the coolant at the nth iteration step and the n+1th concentration distribution at the n+1th iteration step, respectively. Based on the obtained nth and n+1th concentration distributions, the server calculates the concentration difference for the soluble substances in the coolant. If the concentration differences are all less than the concentration difference threshold, the server determines that the relationship for calculating the concentration distribution has converged and determines the n+1th concentration distribution as the concentration distribution for heat and mass transfer analysis. The server calculates the total amount of boron deposition based on the total mass of the corrosion products, obtaining the total amount of boron deposition in the corrosion products.

[0115] Finally, the server analyzes the heat and mass transfer process of the corrosion products based on the obtained temperature distribution in the corrosion products, the flow rate distribution of the coolant, the concentration distribution of soluble substances in the coolant, and the total amount of boron deposition in the corrosion products, thereby obtaining the heat and mass transfer analysis results for the corrosion products.

[0116] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0117] Based on the same inventive concept, embodiments of the present application also provide a heat and mass transfer analysis device for nuclear reactor corrosion products, which is used to implement the aforementioned heat and mass transfer analysis method for nuclear reactor corrosion products. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more embodiments of the heat and mass transfer analysis device for nuclear reactor corrosion products provided below can be found in the aforementioned limitations of the heat and mass transfer analysis method for nuclear reactor corrosion products, and will not be further elaborated here.

[0118] In one embodiment, as shown in FIG4 , a heat and mass transfer analysis device for nuclear reactor corrosion products is provided, comprising:

[0119] The temperature distribution determination module 402 obtains the average thermal conductivity of the corrosion products in the nuclear reactor and determines the temperature distribution of the corrosion products when the coolant is in a saturated state, a nucleate boiling state, and an evaporated state based on the average thermal conductivity.

[0120] The flow rate distribution determining module 404 determines the flow rate distribution of the coolant in the corrosion product based on the pressure distribution in the corrosion product.

[0121] The concentration distribution determination module 406 obtains a concentration relationship between the concentration of boric acid and the concentration of other soluble substances in the coolant, and determines the concentration distribution of the other soluble substances based on the concentration relationship and the boric acid concentration.

[0122] Analysis module 408 analyzes the heat and mass transfer processes within the corrosion product based on the temperature distribution, flow velocity distribution, and soluble species concentration distribution, and determines the concentration of boron after enrichment within the corrosion product. Based on this concentration, the total amount of boron deposited is determined. Soluble species include boric acid and other soluble species.

[0123] In one embodiment, the temperature distribution determination module includes:

[0124] The first data determination unit obtains the porosity of the corrosion product, the solid thermal conductivity of the corrosion product, and the liquid thermal conductivity of the coolant in the corrosion product.

[0125] The second data determination unit determines an average thermal conductivity of the corrosion product based on the porosity, the solid thermal conductivity, and the liquid thermal conductivity.

[0126] In one embodiment, the temperature distribution determination module includes:

[0127] Length acquisition unit, which obtains the thickness of corrosion products.

[0128] The saturation temperature distribution determining unit determines the saturation temperature distribution of the corrosion product when the coolant is saturated based on the average thermal conductivity and the thickness. The temperature distribution includes the saturation temperature distribution.

[0129] In one embodiment, the temperature distribution determination module includes:

[0130] The first relationship determination unit obtains a wick boiling relationship that characterizes the relationship between the thickness of the corrosion product and the temperature of the corrosion product when the coolant is in a nucleate boiling state.

[0131] The nucleate boiling temperature distribution determination unit determines the temperature distribution inside the corrosion product during the nucleate boiling state based on the relationship between the thickness distribution of the corrosion product and the wick boiling state. The temperature distribution includes the temperature distribution during the nucleate boiling state.

[0132] In one embodiment, the heat and mass transfer analysis device for nuclear reactor corrosion products further comprises:

[0133] The second relationship determination unit determines a temperature relationship expression representing the relationship between the thickness of the corrosion product and the temperature of the corrosion product, a flow rate relationship expression representing the relationship between the pressure in the corrosion product and the flow rate of the coolant, and a concentration relationship expression.

[0134] The temperature difference determining unit determines, based on the temperature relationship and the thickness of the corrosion product, an nth temperature distribution of the corrosion product in the nth iteration step and an n+1th temperature distribution of the corrosion product in the n+1th iteration step, and determines a temperature difference between the nth temperature distribution and the n+1th temperature distribution. The nth iteration step and the n+1th iteration step are adjacent iteration steps.

[0135] The flow rate difference determination unit determines an nth flow rate distribution of the coolant in the nth iteration step and an n+1th flow rate distribution of the coolant in the n+1th iteration step based on the flow rate relationship and the pressure in the corrosion product, and determines a flow rate difference between the nth flow rate distribution and the n+1th flow rate distribution.

[0136] The concentration difference determination unit determines the concentration of other soluble substances in the nth concentration distribution of the nth iteration step and the n+1th concentration distribution of the coolant in the n+1th iteration step based on the concentration relationship and the boric acid concentration in the coolant, and determines the concentration difference between the nth concentration distribution and the n+1th concentration distribution.

[0137] The n+2th data determination unit determines the maximum difference among the temperature difference, the flow velocity difference and the concentration difference, and when the maximum difference is less than a preset difference threshold, determines the nth flow velocity distribution as the flow velocity distribution, determines the nth temperature distribution as the temperature distribution, and determines the nth concentration distribution as the concentration distribution of the soluble substance.

[0138] In one embodiment, the temperature distribution determination module includes:

[0139] The third relationship determination unit obtains a three-dimensional coordinate system relationship that characterizes the relationship between the thickness of the corrosion product and the temperature of the corrosion product when the coolant is evaporated to dryness.

[0140] The evaporation temperature distribution determining unit determines the evaporation temperature distribution of the corrosion product based on the relationship between the thickness of the corrosion product and the three-dimensional coordinate system. The temperature distribution includes the evaporation temperature distribution.

[0141] Each module in the heat and mass transfer analysis device for nuclear reactor corrosion products can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in the computer device in the form of software, so that the processor can call and execute the corresponding operations of each module.

[0142] In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be shown in Figure 5. The computer device includes a processor, memory, an input / output (I / O) interface, and a communication interface. The processor, memory, and I / O interface are connected via a system bus, and the communication interface is connected to the system bus via the I / O interface. 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 internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the computer device is used to store data on average thermal conductivity, temperature distribution, pressure distribution, flow rate distribution, boric acid concentration, concentration distribution of other soluble substances, total boron deposition, and total boron deposition. The I / O interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals via a network connection. When executed by the processor, the computer program implements a heat and mass transfer analysis method for nuclear reactor corrosion products.

[0143] Those skilled in the art will understand that the structure shown in FIG5 is merely a block diagram of a portion of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0144] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0145] The average thermal conductivity of corrosion products in a nuclear reactor is obtained, and based on the average thermal conductivity, the temperature distribution of the corrosion products when the coolant is in a saturated state, a nucleate boiling state, and an evaporated state is determined. The flow rate distribution of the coolant in the corrosion products is determined based on the pressure distribution in the corrosion products. The concentration relationship between the boric acid concentration and the concentration of other soluble substances in the coolant is obtained, and based on the concentration relationship and the boric acid concentration, the concentration distribution of other soluble substances is determined. Based on the temperature distribution, flow rate distribution, and the concentration distribution of soluble substances, the heat and mass transfer process of the corrosion products is analyzed to obtain the concentration of boron after enrichment within the corrosion products, and based on the enriched concentration, the total amount of boron deposition is calculated. Soluble substances include boric acid and other soluble substances.

[0146] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0147] The porosity of the corrosion product, the solid thermal conductivity of the corrosion product, and the liquid thermal conductivity of the coolant in the corrosion product are obtained; and the average thermal conductivity of the corrosion product is determined based on the porosity, the solid thermal conductivity, and the liquid thermal conductivity.

[0148] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0149] The thickness of the corrosion product is obtained; based on the average thermal conductivity and the thickness, the saturation temperature distribution of the corrosion product when the coolant is saturated is determined; the temperature distribution includes the saturation temperature distribution.

[0150] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0151] A wick boiling relationship is obtained, which characterizes the relationship between the thickness of the corrosion product and the temperature inside the corrosion product when the coolant is in a nucleate boiling state. Based on the thickness distribution of the corrosion product and the wick boiling relationship, the temperature distribution inside the corrosion product in the nucleate boiling state is determined; the temperature distribution includes the temperature distribution in the nucleate boiling state.

[0152] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0153] Determine a temperature relationship expression that characterizes the relationship between the thickness of the corrosion product and the temperature of the corrosion product, a flow rate relationship expression that characterizes the relationship between the pressure in the corrosion product and the flow rate of the coolant, and a concentration relationship expression; determine the nth temperature distribution of the corrosion product in the nth iteration step and the n+1th temperature distribution of the corrosion product in the n+1th iteration step based on the temperature relationship expression and the thickness of the corrosion product, and determine the temperature difference between the nth temperature distribution and the n+1th temperature distribution; the nth iteration step and the n+1th iteration step are adjacent iteration steps; determine the nth flow rate distribution of the coolant in the nth iteration step and the n+1th flow rate distribution of the coolant in the n+1th iteration step based on the flow rate relationship expression and the pressure in the corrosion product. The method comprises the following steps: determining the nth flow velocity distribution and the n+1th flow velocity distribution, determining the flow velocity difference between the nth flow velocity distribution and the n+1th flow velocity distribution; determining the concentration of other soluble substances in the nth concentration distribution of the nth iteration step, and the n+1th concentration distribution of the coolant in the n+1th iteration step based on the concentration relationship and the boric acid concentration in the coolant, and determining the concentration difference between the nth concentration distribution and the n+1th concentration distribution; determining the maximum difference among the temperature difference, the flow velocity difference and the concentration difference, and when the maximum difference is less than a preset difference threshold, determining the nth flow velocity distribution as the flow velocity distribution, the nth temperature distribution as the temperature distribution, and the nth concentration distribution as the concentration distribution of other soluble substances.

[0154] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0155] A three-dimensional coordinate system relationship equation characterizing the relationship between the thickness of the corrosion product and the temperature of the corrosion product when the coolant is evaporated is obtained; based on the relationship equation between the thickness of the corrosion product and the three-dimensional coordinate system, an evaporation temperature distribution of the corrosion product is determined; the temperature distribution includes an evaporation temperature distribution.

[0156] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0157] The average thermal conductivity of corrosion products in a nuclear reactor is obtained, and based on the average thermal conductivity, the temperature distribution of the corrosion products when the coolant is in a saturated state, a nucleate boiling state, and an evaporated state is determined. The flow rate distribution of the coolant in the corrosion products is determined based on the pressure distribution in the corrosion products. The concentration relationship between the boric acid concentration and the concentration of other soluble substances in the coolant is obtained, and based on the concentration relationship and the boric acid concentration, the concentration distribution of other soluble substances is determined. Based on the temperature distribution, flow rate distribution, and the concentration distribution of soluble substances, the heat and mass transfer process of the corrosion products is analyzed to obtain the concentration of boron after enrichment within the corrosion products, and based on the enriched concentration, the total amount of boron deposition is calculated. Soluble substances include boric acid and other soluble substances.

[0158] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0159] The porosity of the corrosion product, the solid thermal conductivity of the corrosion product, and the liquid thermal conductivity of the coolant in the corrosion product are obtained; and the average thermal conductivity of the corrosion product is determined based on the porosity, the solid thermal conductivity, and the liquid thermal conductivity.

[0160] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0161] The thickness of the corrosion product is obtained; based on the average thermal conductivity and the thickness, the saturation temperature distribution of the corrosion product when the coolant is saturated is determined; the temperature distribution includes the saturation temperature distribution.

[0162] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0163] A wick boiling relationship is obtained, which characterizes the relationship between the thickness of the corrosion product and the internal temperature of the corrosion product when the coolant is in a nucleate boiling state. Based on the thickness distribution of the corrosion product and the wick boiling relationship, the temperature distribution inside the corrosion product in the nucleate boiling state is determined; the temperature distribution includes the temperature distribution during nucleate boiling.

[0164] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0165] Determine a temperature relationship expression that characterizes the relationship between the thickness of the corrosion product and the temperature of the corrosion product, a flow rate relationship expression that characterizes the relationship between the pressure in the corrosion product and the flow rate of the coolant, and a concentration relationship expression; determine the nth temperature distribution of the corrosion product in the nth iteration step and the n+1th temperature distribution of the corrosion product in the n+1th iteration step based on the temperature relationship expression and the thickness of the corrosion product, and determine the temperature difference between the nth temperature distribution and the n+1th temperature distribution; the nth iteration step and the n+1th iteration step are adjacent iteration steps; determine the nth flow rate distribution of the coolant in the nth iteration step and the n+1th flow rate distribution of the coolant in the n+1th iteration step based on the flow rate relationship expression and the pressure in the corrosion product. The method comprises the following steps: determining the nth flow velocity distribution and the n+1th flow velocity distribution, determining the flow velocity difference between the nth flow velocity distribution and the n+1th flow velocity distribution; determining the concentration of other soluble substances in the nth concentration distribution of the nth iteration step, and the n+1th concentration distribution of the coolant in the n+1th iteration step based on the concentration relationship and the boric acid concentration in the coolant, and determining the concentration difference between the nth concentration distribution and the n+1th concentration distribution; determining the maximum difference among the temperature difference, the flow velocity difference and the concentration difference, and when the maximum difference is less than a preset difference threshold, determining the nth flow velocity distribution as the flow velocity distribution, the nth temperature distribution as the temperature distribution, and the nth concentration distribution as the concentration distribution of other soluble substances.

[0166] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0167] A three-dimensional coordinate system relationship equation characterizing the relationship between the thickness of the corrosion product and the temperature of the corrosion product when the coolant is evaporated is obtained; based on the relationship equation between the thickness of the corrosion product and the three-dimensional coordinate system, an evaporation temperature distribution of the corrosion product is determined; the temperature distribution includes an evaporation temperature distribution.

[0168] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the following steps:

[0169] The average thermal conductivity of corrosion products in a nuclear reactor is obtained, and based on the average thermal conductivity, the temperature distribution of the corrosion products when the coolant is in a saturated state, a nucleate boiling state, and an evaporated state is determined. The flow rate distribution of the coolant in the corrosion products is determined based on the pressure distribution in the corrosion products. The concentration relationship between the boric acid concentration and the concentration of other soluble substances in the coolant is obtained, and based on the concentration relationship and the boric acid concentration, the concentration distribution of other soluble substances is determined. Based on the temperature distribution, flow rate distribution, and the concentration distribution of soluble substances, the heat and mass transfer process of the corrosion products is analyzed to obtain the concentration of boron after enrichment within the corrosion products, and based on the enriched concentration, the total amount of boron deposition is calculated. Soluble substances include boric acid and other soluble substances.

[0170] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0171] The porosity of the corrosion product, the solid thermal conductivity of the corrosion product, and the liquid thermal conductivity of the coolant in the corrosion product are obtained; and the average thermal conductivity of the corrosion product is determined based on the porosity, the solid thermal conductivity, and the liquid thermal conductivity.

[0172] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0173] The thickness of the corrosion product is obtained; based on the average thermal conductivity and the thickness, the saturation temperature distribution of the corrosion product when the coolant is saturated is determined; the temperature distribution includes the saturation temperature distribution.

[0174] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0175] A wick boiling relationship is obtained, which characterizes the relationship between the thickness of the corrosion product and the temperature of the corrosion product when the coolant is in a nucleate boiling state. Based on the thickness distribution of the corrosion product and the wick boiling relationship, the temperature distribution of the corrosion product in the nucleate boiling state is determined. The temperature distribution includes the temperature distribution in the nucleate boiling state.

[0176] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0177] Determine a temperature relationship expression that characterizes the relationship between the thickness of the corrosion product and the temperature of the corrosion product, a flow rate relationship expression that characterizes the relationship between the pressure in the corrosion product and the flow rate of the coolant, and a concentration relationship expression; determine the nth temperature distribution of the corrosion product in the nth iteration step and the n+1th temperature distribution of the corrosion product in the n+1th iteration step based on the temperature relationship expression and the thickness of the corrosion product, and determine the temperature difference between the nth temperature distribution and the n+1th temperature distribution; the nth iteration step and the n+1th iteration step are adjacent iteration steps; determine the nth flow rate distribution of the coolant in the nth iteration step and the n+1th flow rate distribution of the coolant in the n+1th iteration step based on the flow rate relationship expression and the pressure in the corrosion product. The method comprises the following steps: determining the nth flow velocity distribution of the nth iteration step and the n+1th flow velocity distribution, and determining the flow velocity difference between the nth flow velocity distribution and the n+1th flow velocity distribution; determining the concentration of other soluble substances in the nth concentration distribution of the nth iteration step and the n+1th concentration distribution of the coolant in the n+1th iteration step based on the concentration relationship and the boric acid concentration in the coolant, and determining the concentration difference between the nth concentration distribution and the n+1th concentration distribution; determining the maximum difference among the temperature difference, the flow velocity difference and the concentration difference, and when the maximum difference is less than a preset difference threshold, determining the nth flow velocity distribution as the flow velocity distribution, the nth temperature distribution as the temperature distribution, and the nth concentration distribution as the concentration distribution of the soluble substances.

[0178] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0179] A three-dimensional coordinate system relationship equation characterizing the relationship between the thickness of the corrosion product and the temperature of the corrosion product when the coolant is evaporated is obtained; based on the relationship equation between the thickness of the corrosion product and the three-dimensional coordinate system, an evaporation temperature distribution of the corrosion product is determined; the temperature distribution includes an evaporation temperature distribution.

[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, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of relevant countries and regions.

[0181] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented 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 memory, database or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of 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 the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processor involved in the various embodiments provided herein may be, but are not limited to, a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, and the like.

[0182] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above 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.

[0183] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for analyzing heat and mass transfer of nuclear reactor corrosion products, characterized in that: The method comprises: Obtaining an average thermal conductivity of corrosion products in a nuclear reactor, and determining temperature distributions of the corrosion products when the coolant is in a saturated state, a nucleate boiling state, and an evaporated state, respectively, based on the average thermal conductivity; determining a flow rate distribution of a coolant in the corrosion product based on a pressure distribution in the corrosion product; Obtaining a concentration relationship between the concentration of boric acid and the concentration of other soluble substances in the coolant, and determining the concentration distribution of the other soluble substances based on the concentration relationship and the boric acid concentration; Based on the temperature distribution, the flow velocity distribution, and the concentration distribution of soluble substances, the heat and mass transfer processes inside the corrosion product are analyzed to obtain the concentration of boron after enrichment inside the corrosion product, and the total amount of boron deposition is obtained based on the enriched concentration; the soluble substances include boric acid and other soluble substances.

2. The method according to claim 1, characterized in that The step of obtaining the average thermal conductivity of the corrosion products comprises: Obtaining the porosity of the corrosion product, the solid thermal conductivity of the corrosion product, and the liquid thermal conductivity of the coolant in the corrosion product; An average thermal conductivity of the corrosion product is determined based on the porosity, the solid thermal conductivity, and the liquid thermal conductivity.

3. The method according to claim 1, characterized in that Determining the temperature distribution inside the corrosion product when the coolant is in a saturated state based on the average thermal conductivity includes: Obtaining the thickness of the corrosion product; Based on the average thermal conductivity and the thickness, a saturation temperature distribution of the corrosion product when the coolant is in a saturated state is determined; the temperature distribution includes a saturation temperature distribution.

4. The method according to claim 1, characterized in that: Determining the temperature distribution of the corrosion product when the coolant is in a nucleate boiling state based on the average thermal conductivity includes: Obtaining a wick boiling relationship that characterizes the relationship between the thickness of the corrosion product and the temperature inside the corrosion product when the coolant is in a nucleate boiling state; Based on the thickness distribution of the corrosion product and the wick boiling relationship, the temperature distribution inside the corrosion product in the nucleate boiling state is determined; the temperature distribution includes the temperature distribution in the nucleate boiling state.

5. The method according to claim 1, characterized in that The method further comprises: Determine a temperature relationship equation characterizing the relationship between the thickness of the corrosion product and the temperature of the corrosion product, a flow rate relationship equation characterizing the relationship between the pressure in the corrosion product and the flow rate of the coolant, and a concentration relationship equation; Based on the temperature relationship and the thickness of the corrosion product, determine the nth temperature distribution of the corrosion product in the nth iteration step and the n+1th temperature distribution of the corrosion product in the n+1th iteration step, and determine the temperature difference between the nth temperature distribution and the n+1th temperature distribution; the nth iteration step and the n+1th iteration step are adjacent iteration steps; n is a positive integer; Based on the flow velocity relationship and the pressure in the corrosion product, determine an nth flow velocity distribution of the coolant in the nth iteration step and an n+1th flow velocity distribution of the coolant in the n+1th iteration step, and determine a flow velocity difference between the nth flow velocity distribution and the n+1th flow velocity distribution; Based on the concentration relationship and the boric acid concentration in the coolant, determine the concentration of the other soluble substances in the nth concentration distribution in the nth iteration step, and the n+1th concentration distribution of the coolant in the n+1th iteration step, and determine the concentration difference between the nth concentration distribution and the n+1th concentration distribution; Determine the maximum difference among the temperature difference, the flow velocity difference and the concentration difference, and when the maximum difference is less than a preset difference threshold, determine the nth flow velocity distribution as the flow velocity distribution, determine the nth temperature distribution as the temperature distribution, and determine the nth concentration distribution as the concentration distribution of the other soluble substances.

6. The method according to claim 1, characterized in that Determining the temperature distribution of the corrosion product when the coolant is in an evaporated state based on the average thermal conductivity includes: Obtaining a three-dimensional coordinate system relationship formula that characterizes the relationship between the thickness of the corrosion product and the temperature of the corrosion product when the coolant is evaporated to dryness; Based on the relationship between the thickness of the corrosion product and the three-dimensional coordinate system, the evaporation temperature distribution of the corrosion product is determined; the temperature distribution includes the evaporation temperature distribution.

7. A heat and mass transfer analysis device for nuclear reactor corrosion products, characterized in that: The device comprises: a temperature distribution determination module, which obtains an average thermal conductivity of corrosion products in the nuclear reactor, and determines, based on the average thermal conductivity, temperature distributions of the corrosion products when the coolant is in a saturated state, a nucleate boiling state, and an evaporated state; a flow rate distribution determining module, which determines the flow rate distribution of the coolant in the corrosion product based on the pressure distribution in the corrosion product; A concentration distribution determination module, which obtains a concentration relationship between the concentration of boric acid in the coolant and the concentration of other soluble substances, and determines the concentration distribution of the other soluble substances based on the concentration relationship and the boric acid concentration; The analysis module analyzes the heat and mass transfer process inside the corrosion product based on the temperature distribution, the flow velocity distribution, and the concentration distribution of soluble substances, obtains the concentration of boron after enrichment inside the corrosion product, and obtains the total amount of boron deposition based on the enriched concentration; the soluble substances include boric acid and other soluble substances.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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