Metal fuel irradiation test physical thermal analysis method, device, equipment and medium

Abstract

The application discloses a metal fuel irradiation test physical thermal analysis method, device, equipment and medium, relates to the field of nuclear reactor physics and thermal engineering, and comprises the following steps: determining the burnup depth information of the metal fuel according to the measured thermal power, inputting the burnup depth information into a pre-configured structure swelling model for analysis, obtaining the volume swelling rate of the metal fuel in the axial direction and the radial direction, updating the structure size of the metal fuel according to the volume swelling rate, and updating the thermal conductivity of the metal fuel according to the updated structure size; according to the burnup depth information, the updated structure size of the metal fuel and the burnup distribution situation calculated by the burnup management calculation model based on the determinism method, the burnup distribution curve of the metal fuel at the corresponding irradiation time is refitted, the heat release calculation is carried out according to the burnup distribution curve, and the heat release distribution information of the metal fuel is obtained; the heat release distribution information of the metal fuel, the updated structure size and the thermal conductivity of the metal fuel are input into a sub-channel analysis model for thermal analysis, and the key thermal parameters of the metal fuel are obtained.

Description

Technical Field

[0001] The present invention relates to the field of nuclear reactor physics and thermal engineering, and more specifically, to a physical thermal analysis method, device, equipment and medium for metal fuel irradiation testing. Background Art

[0002] For metal fuel irradiation tests, the irradiation test fuel rods used a toroidal core + liquid sodium structure design. In early irradiation tests, the effective density of the toroidal core was ~85%. As test data accumulated, a relationship between the fission gas release rate and fuel core swelling was summarized. When the swelling caused by fission gas approaches 30%, the fission gas in the fuel core is released into the cavity above the fuel core due to bubble communication, thereby hollowing out the fuel structure near the cladding and reducing the risk of cladding damage due to FCMI. For an annular core with an effective density of -75%, when the fuel core contacts the cladding, its radial volume swelling reaches ~33%. This swelling facilitates the release of most fission gas. Therefore, the ~75% effective density design was adopted in the later MARK-II, EBR-II, and IFR-related irradiation short rod designs.

[0003] During the irradiation of metal alloy fuels, the effects of multiple factors, such as irradiation dose, temperature, and alloy composition, on swelling must be considered, requiring a comprehensive multi-factor analysis to obtain more accurate swelling calculations. Currently, related technologies apply multi-physics coupled computation to the numerical simulation of metal fuels. For example, CASL integrates existing core design and analysis technologies to conduct coupled multi-physics, multi-process, multi-dimensional, and multi-scale reactor numerical simulations. However, this technology is computationally intensive. Current related technologies have also proposed numerical fuel rod models based on tight multi-physics coupled computations, with independent heat conduction, mechanical, and neutron transport calculation modules, and have developed the numerical fuel rod program YUAN. However, these technologies primarily focus on numerical simulations of swelling behavior, burnup changes, and temperature field distributions for known metal fuels. For metal fuels undergoing in-reactor irradiation testing, the swelling behavior (such as axial and radial swelling) and stress changes after irradiation testing are still under development and cannot be analyzed using the aforementioned techniques.

[0004] Therefore, how to analyze the swelling of metal fuel after irradiation test and the fuel consumption distribution after swelling is an urgent problem that needs to be solved. Summary of the Invention

[0005] The purpose of the present invention is to provide a physical thermal analysis method, device, equipment and medium for metal fuel irradiation test, so as to solve the problem that the related technology cannot analyze the swelling of metal fuel after irradiation test and the fuel consumption distribution state after swelling.

[0006] In a first aspect, the present application provides a method for physical and thermal analysis of metal fuel irradiation test, comprising:

[0007] acquiring a measured thermal power after the current stage irradiation test is completed;

[0008] determining burnup depth information of the metal fuel according to the measured thermal power, inputting the burnup depth information into a pre-configured structure swelling model for analysis to obtain volume swelling rates of the metal fuel in the axial and radial directions, updating structure sizes of the metal fuel according to the volume swelling rates, and updating thermal conductivities of the metal fuel according to the updated structure sizes; wherein the structure sizes refer to axial height and radial size;

[0009] re-fitting a burnup distribution curve of the metal fuel at a corresponding irradiation time according to the burnup depth information, the updated structure sizes of the metal fuel, and a burnup distribution obtained by calculation of a deterministic method-based burnup management calculation model, performing heat release calculation according to the burnup distribution curve to obtain heat release distribution information of the metal fuel;

[0010] inputting the heat release distribution information of the metal fuel, the updated structure sizes and the thermal conductivities of the metal fuel into a sub-channel analysis model for thermal analysis to obtain key thermal parameters of the metal fuel;

[0011] judging whether the key thermal parameters meet target parameters of the current stage irradiation test, and adjusting operating parameters of a next stage irradiation test if the key thermal parameters do not meet the target parameters.

[0012] In an implementation scheme, the burnup depth information of the metal fuel is determined according to the measured thermal power, specifically, the measured thermal power is input into a nuclear power calculation model for calculation to obtain a nuclear power calculation value;

[0013] the burnup depth information of the metal fuel is determined according to the nuclear power calculation value and the irradiation time.

[0014] the measured thermal power is input into a pre-configured deterministic method-based burnup management calculation model for calculation to determine the burnup depth information of the metal fuel.

[0015] In an implementation scheme, the burnup distribution curve of the metal fuel at the corresponding irradiation time is re-fitted by using a cosine function in combination with the burnup distribution obtained by calculation of the deterministic method-based burnup management calculation model and the updated structure sizes of the metal fuel.

[0016] In an implementation scheme, the burnup distribution curve corresponding to the burnup depth information when the metal fuel swells in the radial and / or axial directions is fitted by adjusting the amplitude and / or frequency of the cosine function.

[0017] A second aspect of the present invention provides a physical thermal analysis device for metal fuel irradiation testing, the device comprising:

[0018] The power acquisition module is used to obtain the measured thermal power after the current stage of irradiation test;

[0019] A parameter update module is used to determine the burnup depth information of the metal fuel based on the measured thermal power, input the burnup depth information into a pre-configured structural swelling model for analysis, and obtain the volumetric swelling ratio of the metal fuel in the axial and radial directions. The structural dimensions of the metal fuel are updated based on the volumetric swelling ratio, and the thermal conductivity of the metal fuel is updated based on the updated structural dimensions. The structural dimensions refer to the axial height and radial dimensions.

[0020] The heat release distribution information calculation module is used to re-fit the burnup distribution curve of the metal fuel at the corresponding irradiation time based on the burnup depth information, the updated structural dimensions of the metal fuel, and the burnup distribution calculated by the burnup management calculation model based on the deterministic method, and perform heat release calculation based on the burnup distribution curve to obtain the heat release distribution information of the metal fuel;

[0021] The thermal analysis module is used to input the heat release distribution information of the metal fuel, the updated structural dimensions and thermal conductivity of the metal fuel into the sub-channel analysis model for thermal analysis to obtain the key thermal parameters of the metal fuel;

[0022] The judgment and adjustment module is used to judge whether the key thermal parameters meet the target parameters of the current stage of irradiation test. If not, the operating parameters of the next stage of irradiation test are adjusted.

[0023] In one implementation, the parameter update module is also used to determine the burnup depth information of the metal fuel based on the measured thermal power. Specifically, the measured thermal power is input into the nuclear power estimation model for calculation to obtain the nuclear power estimation value; and the burnup depth information of the metal fuel is determined based on the nuclear power estimation value and the irradiation time.

[0024] In one implementation, the heat release distribution information calculation module is also used to combine the fuel consumption distribution calculated by the fuel consumption management calculation model based on the deterministic method and the updated structural dimensions of the metal fuel, and use the cosine function to re-fit the fuel consumption distribution curve of the metal fuel under the corresponding irradiation time.

[0025] In one implementation, the burnup distribution curve corresponding to the burnup depth information when the metal fuel swells radially and / or axially is fitted by adjusting the amplitude and / or frequency of the cosine function.

[0026] According to a third aspect of the present invention, an electronic device is provided, comprising a processor, a memory, and a computer program stored in the memory and executable by the processor, wherein when the computer program is executed by the processor, the steps of a physical thermal analysis method for metal fuel irradiation testing provided in the first aspect of the present invention are implemented.

[0027] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the steps of a physical thermal analysis method for metal fuel irradiation testing provided in the first aspect of the present invention are implemented.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] In a physical thermal analysis method for metal fuel irradiation test provided by the present invention, first, the measured thermal power after the current stage of irradiation test is obtained; the burnup depth information of the metal fuel is determined based on the measured thermal power, and the burnup depth information is input into a pre-configured structural swelling model for analysis to obtain the volume swelling rate of the metal fuel in the axial and radial directions, the structural size of the metal fuel is updated based on the volume swelling rate, and the thermal conductivity of the metal fuel is updated based on the updated structural size; wherein the structural size refers to the axial height and radial size; the burnup distribution curve of the metal fuel at the corresponding irradiation time is fitted based on the burnup depth information, and the heat release is calculated based on the burnup distribution curve to obtain the heat release distribution information of the metal fuel; the heat release distribution information of the metal fuel, the updated structural size and thermal conductivity of the metal fuel are input into a sub-channel analysis model for thermal analysis to obtain the key thermal parameters of the metal fuel; it is judged whether the key thermal parameters meet the target parameters of the current stage of irradiation test, and if not, the operating parameters of the next stage of irradiation test are adjusted. It can be seen that the present invention first combines the burnup depth information of the metal fuel and the structural swelling model to determine the changes in the structural size and thermal conductivity of the metal fuel, and then, combines the burnup depth information to fit the burnup distribution curve of the metal fuel at the corresponding irradiation time, and uses this to perform heat release calculation to determine the heat release distribution information of the metal fuel. Finally, a sub-channel analysis model is used to analyze the heat release distribution information, structural size and thermal conductivity of the metal fuel after swelling, thereby realizing the analysis of the physical thermal parameters of the irradiation swelling process in the metal fuel pile, thereby solving the problem that the relevant technology cannot analyze the swelling of the metal fuel after irradiation test and the burnup distribution state and key thermal parameters (metal fuel core temperature, etc.) after swelling. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0031] Figure 1 A schematic flow chart of a physical thermal analysis method for metal fuel irradiation testing provided by an embodiment of the present invention;

[0032] Figure 2 A flowchart of the physical thermal analysis of the swelling of the gold-burning fuel after irradiation provided by an embodiment of the present invention;

[0033] Figure 3 A graph showing the relationship between metal swelling and burnup provided in an embodiment of the present invention;

[0034] Figure 4 A block diagram of the principle of a physical thermal analysis device for metal fuel irradiation testing provided by an embodiment of the present invention;

[0035] Figure 5 A schematic structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0037] It should be noted that the terms "include" or "may include" used in various embodiments of the present application indicate the presence of the claimed function, operation or element, and do not limit the addition of one or more functions, operations or elements. In addition, as used in various embodiments of the present application, the terms "include", "have" and their cognates are only intended to indicate specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the presence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0038] In various embodiments of the present application, the expression "or" or "at least one of B or / and C" includes any or all combinations of the words listed simultaneously. For example, the expression "B or C" or "at least one of B or / and C" may include B, may include C, or may include both B and C.

[0039] Please refer to Figure 1 , Figure 1 A schematic flow chart of a physical thermal analysis method for metal fuel irradiation test provided by an embodiment of the present invention is shown as follows: Figure 1 As shown, the method includes:

[0040] S101, obtaining the actual thermal power after the irradiation test of the current stage is completed.

[0041] In this embodiment, the thermal power calculation formula is as follows: P t,测量 =c p m(t out -t in ), where c p is the constant-pressure specific heat capacity corresponding to the average temperature and average pressure of the coolant at the inlet and outlet of the irradiation device; m is the coolant flow rate in the irradiation device; t out is the coolant temperature at the outlet of the irradiation device; t in is the coolant temperature at the outlet of the irradiation device.

[0042] Thermocouples are installed at the inlet and outlet of the irradiator to measure coolant temperature, and a flowmeter is installed at the inlet to measure coolant flow. The inlet and outlet pressures of the irradiator are based on the reactor core inlet and outlet pressure data. Based on the average coolant temperature and pressure, the corresponding constant-pressure specific heat capacity is calculated using IAPWS-IF97 standard water and steam property calculation software. Using these measured data and the above formula, the measured thermal power is calculated.

[0043] S102: Determine the burnup depth information of the metal fuel based on the measured thermal power, input the burnup depth information into a pre-configured structural swelling model for analysis, and obtain the volumetric swelling ratio of the metal fuel in the axial and radial directions. Update the structural dimensions of the metal fuel based on the volumetric swelling ratio, and update the thermal conductivity of the metal fuel based on the updated structural dimensions. The structural dimensions refer to the axial height and radial dimensions.

[0044] Specifically, metal fuel, as a core component of nuclear reactors, has a direct impact on its safety and economics. Structural swelling is a common problem with metal fuel during irradiation, causing changes in the dimensions of fuel elements, which in turn affects the reactor's power distribution and burnup management.

[0045] In this embodiment, the burnup depth information of the metal fuel is determined based on the measured thermal power. Specifically, the measured thermal power is input into the nuclear power estimation model for calculation to obtain the nuclear power estimation value; and the burnup depth information of the metal fuel is determined based on the nuclear power estimation value and the irradiation time.

[0046] Specifically, the nuclear power estimation model deducts the reactor's deposited energy within the irradiator from the measured thermal power and divides the result by a correction factor to obtain the estimated nuclear power value. This thermal power includes the reactor's deposited energy within the irradiator, which needs to be deducted to obtain the portion of energy generated by metal fuel fission that is deposited in the irradiator. This is then divided by the correction factor to obtain the total energy generated by metal fuel fission (i.e., the nuclear power of the metal fuel). The formula is as follows:

[0047] Where: PN Represents the fission energy of metal fuel nuclear power; P t,测量 It represents the heat release power of the test section derived based on the heat balance principle; P 沉积 represents the deposition energy of the reactor in the irradiation device; a represents the proportional correction factor considering the deposition of metal fuel fission energy in the irradiation device. 沉积 The statistics can be calculated by establishing a Monte Carlo model.

[0048] According to the metal fuel nuclear power P N (MW), the number of irradiation test days T(d), and the initial uranium charge M(t) can be used to calculate the nuclear fuel burnup (MWd / tU), that is: The energy produced by each fission of nuclear fuel can be converted into fission / cm 3 , or atomic burnup at% (the ratio of the number of nuclear fuel atoms consumed to the initial number of nuclear fuel atoms).

[0049] like Figure 2 As shown, in this embodiment, the measured thermal power is input into a pre-configured burnup management calculation model based on a deterministic method for calculation to determine the burnup depth information of the metal fuel.

[0050] Specifically, the deterministic approach is a calculation method based on physical principles and mathematical models. It calculates the nuclear fuel burnup process by accurately describing the neutron nuclear reaction process in the reactor. The key elements of the burnup management calculation model are as follows:

[0051] Burnup equation: The burnup equation is a mathematical equation that describes the time-dependent variation in the number of nuclides. It is based on the principle of conservation of mass and takes into account the production and destruction rates of nuclides. By solving the burnup equation, we can determine how the number of each nuclide in the reactor changes over time.

[0052] Take a burn chain as an example: (g is a different energy group)

[0053] Assume that the fuel consumption calculation of step n-1 has been completed and N n-1 and The fuel consumption budget for step n is as follows:

[0054] N n-1 As the initial value, use and Calculate A1, A2, F1, and C1, and solve the burnup equation to obtain the kernel density budget value.

[0055] Then the fuel consumption correction is performed, still in N n-1As the initial value, the macroscopic cross section is calculated using the kernel density budget value, and then the core calculation is performed to obtain the neutron flux, the neutron flux average is calculated using the neutron flux, and finally the A1, A2, F1 and C1 are calculated using the neutron flux average. Replace A1, A2, F1 and C1 in the burnup equation to solve and get the corrected kernel density. Therefore, the correction of burnup can improve the accuracy of core diffusion calculation.

[0056] Neutron flux distribution: Neutron flux distribution is the spatial distribution of neutron density in the reactor. It determines the nuclear reaction rate in each part of the reactor, thereby affecting the production and consumption of nuclides. In the burnup management calculation model, it is necessary to accurately calculate the neutron flux distribution to obtain accurate burnup results. It should be noted that the calculation of neutron flux is a conventional technical means, and this embodiment does not make specific description.

[0057] Reactivity control: Reactivity control is the key to maintaining the stable operation of the reactor. During the operation of the reactor, due to the change of fuel burnup and core power distribution, the reactivity will change. Therefore, it is necessary to adjust the control parameters (such as the position of the control rod and other absorber assemblies) of the reactor to maintain the stability of the reactivity.

[0058] Fuel assembly parameters: The structure of the fuel assembly, the enrichment of the fuel, the diameter of the element and the thickness of the cladding, etc. Parameters will affect the burnup process of the reactor. In the burnup management calculation model, it is necessary to accurately input these parameters to obtain accurate burnup results.

[0059] Furthermore, the main mechanisms of metal fuel structure swelling include the release and accumulation of fission gases, grain boundary migration and pore formation, etc. When metal fuel is irradiated, a large amount of fission gas will be produced. These gases will accumulate and form bubbles in the fuel through atomic diffusion at high temperature. With the continuous increase of bubble size and number, they will gather on the grain boundary, eventually leading to the swelling of the fuel.

[0060] The construction of the metal fuel structure swelling model usually needs to consider the following key factors: Fission gas production and release: Accurate calculation of the production rate and release mechanism of fission gas, as well as their diffusion and accumulation process in the fuel. Material properties: Including the thermal expansion coefficient, elastic modulus, yield strength and other physical properties of the fuel, as well as the compatibility of the fuel and the cladding material, etc. Irradiation conditions: Including irradiation dose, irradiation temperature, irradiation time, etc., which will affect the swelling behavior of the fuel. Swelling amount calculation: Based on the above factors, the swelling amount of the fuel is calculated through mathematical models or finite element simulation methods.

[0061] Based on this, the burnup depth of the metal fuel is determined using a deterministic burnup management calculation model. This burnup depth information is then input into a pre-configured structural swelling model for analysis, yielding the axial and radial volumetric swelling ratios of the metal fuel after irradiation. Based on these axial and radial volumetric swelling ratios, the metal fuel's structural dimensions can be calculated, and the thermal conductivity of the metal fuel can be updated based on the updated structural dimensions.

[0062] Specifically, after irradiation, the metal fuel's core height and radial dimensions change, along with the internal atomic density distribution. Based on the deterministic diffusion equation, a method that mixes the core material cross-sectional parameters with the cross-sectional parameters of the gas within the annular core provides more accurate estimation and computational precision for handling non-uniform material physical properties and large gradients in thermal neutron flux near interfaces. In the actual calculation process, the physical model of the metal fuel irradiation device has a fixed mesh. The changes in the metal fuel's nuclear power after swelling are reflected through changes in macroscopic cross-sectional parameters. To account for these changes in cross-sectional parameters, a macroscopic cross-sectional library is established. Based on literature-based swelling data, the post-swelling structure and burnup distribution corresponding to the atomic burnup are pre-established (processed using the following method). These are then generated into small-group cross-sectional parameters corresponding to the fuel management program using a cross-sectional generator (such as HELIOS). Based on the burnup information calculated by the fuel management program, the cross-sectional library is used to track and verify the heat release of the metal fuel during the irradiation test.

[0063] Please refer to Figure 3 , shows the relationship between the total volume swelling, radial volume swelling, and axial volume swelling of metal fuel and burnup. Since the total swelling of metal fuel can be divided into two parts: the swelling caused by solid fission products and the swelling caused by gas, namely:

[0064] (ΔV / V) total =(ΔV / V) s +(ΔV / V) g

[0065] For solid swelling, BISON recommends the following calculation method:

[0066] (ΔV / V) total = 1.5% (per at%) (every 1 at% atomic fuel consumption increases by 1.5% solid volume swelling)

[0067] The swelling caused by gas is obtained by subtracting the solid swelling from the total swelling. The porosity can be obtained from the swelling caused by gas. The porosity calculation formula is shown below.

[0068] Where, (ΔV / V) g Refers to swelling caused by gas.

[0069] Taking a certain metal fuel as an example, its thermal conductivity calculation formula is as follows: Where P is the porosity; k0 is the thermal conductivity of the metal fuel when there is no porosity. The calculation formula can be referred to as: k0 = A + BT + CT 2 ;

[0070] A=17.5[(1-2.23W Zr ) / (1+1.61W Zr )-2.62W Pu ];

[0071] B=0.0154[(1+0.061W Zr ) / (1+1.61W Zr )+0.90W Pu ];

[0072] C = 9.38 × 10 -6 (1-2.7W Pu ); where T is temperature; W Z r is the weight percentage of zirconium alloy; W P u is the weight percentage of plutonium.

[0073] S103 , fitting a burnup distribution curve of the metal fuel under the corresponding irradiation time according to the burnup depth information, performing heat release calculation according to the burnup distribution curve, and obtaining heat release distribution information of the metal fuel.

[0074] In this embodiment, the burnup information obtained above is the burnup depth information obtained by inferring the thermal power measurement value. This information deviates from the calculated value obtained by the burnup management calculation model based on the deterministic method. Since the burnup distribution information obtained by the calculation model is more detailed, the burnup depth calculated from the measured value is used as the basis, and the detailed burnup distribution obtained by the calculation model is corrected, that is, the correction is made according to the proportion: The corrected burnup distribution curve is fitted, and then the burnup distribution curve is refitted according to the changes in the metal fuel structure size. According to the new burnup distribution, the small group cross-sectional parameters of the irradiation device required by the fuel management program are remade through the cross-sectional production program, and the cross-sectional parameters are updated. Finally, the new heat release distribution of the metal fuel can be calculated according to the fuel management program.

[0075] Considering that metal swelling behavior is difficult to track and predict, and the burnup distribution after metal swelling is even more difficult to track and predict, how to deal with metal swelling and the burnup distribution after swelling is a difficult point in most metal irradiation tests. Currently, for the research stage, the behavior of metal swelling is referenced to literature data. For the burnup distribution curve after swelling, the following method is used:

[0076] Based on the burnup depth information calculated by the burnup management calculation model, the cosine function is used to fit the burnup depth information to obtain the burnup distribution curve of the metal fuel corresponding to the irradiation time. The burnup distribution curve is fitted into the cosine function form along the axial direction. Its basic form is as follows: Y = C0 + A·cos(π·(xx c ) / w), where C0 represents the intercept, A represents the amplitude, x represents the axial height, and w represents the angular frequency. Indicates the initial phase.

[0077] Without considering the structural swelling, the corresponding fuel consumption distribution curves at different fuel consumption steps in different furnace sections are:

[0078] Y LR =C LR0 +A LR ·cos(π·(xx c ) / w LR ), by fitting the cosine function, the fuel consumption distribution information Y of the metal fuel in the corresponding furnace section and corresponding fuel consumption step is obtained. LR .

[0079] In some embodiments, the burnup distribution curve corresponding to the burnup depth information when the metal fuel swells radially and / or axially is fitted by adjusting the amplitude and / or frequency of the cosine function.

[0080] Specifically, when only radial swelling is considered, by adjusting the amplitude A LR The burnup is redistributed and the burnup depth of the entire metal fuel is made consistent with the burnup depth when the structural swelling is not considered. When only the axial swelling is considered, the frequency w is adjusted. LR Flatten the cosine function distribution and make the burnup depth of the entire metal fuel consistent with the burnup depth when the structural swelling is not considered. If both radial and axial swelling are considered, adjust A at the same time. LR and w LR Make the burnup depth of the entire metal fuel consistent with the burnup depth when structural swelling is not considered.

[0081] Right now

[0082] It can be seen that this embodiment adopts a simplified linear power density processing method. Instead of considering the effect of the decrease in fission atom density after core swelling and the change in the core axial burnup information on the linear power density, this method simulates the dynamic changes of the cosine waveform. While ensuring that the area within a wavelength remains unchanged, the burnup distribution information is adjusted based on the change pattern of the peak and wavelength. The core axial linear power distribution is then recalculated and analyzed, thereby more accurately determining the burnup distribution curve of the metal fuel.

[0083] S104, input the heat release distribution information of the metal fuel, the updated structure size and thermal conductivity of the metal fuel into a sub-channel analysis model to perform thermal analysis and obtain key thermal parameters of the metal fuel.

[0084] In the embodiment, the sub-channel analysis model is a method of dividing the coolant flow channel in the fuel assembly into a plurality of small channels (i.e., sub-channels) that are interconnected and interact with each other. There is exchange or transfer of mass, momentum and energy of the coolant between the sub-channels, i.e., mixing. By listing the coolant mass, energy and momentum conservation equations for all the sub-channels respectively and using appropriate boundary conditions or initial condition types to solve simultaneously, detailed thermal-hydraulic parameters in the reactor can be obtained.

[0085] Based on the basic principles of fluid mechanics, the conservation equations (continuity equation, momentum equation and energy equation) for the coolant flow and heat exchange in the irradiation device are as follows:

[0086] In the formula, σ is the stress tensor, is the unit mass force, and is the unit mass internal energy is the heat flux density, and Φ is the dissipation function.

[0087] The heat conduction equation is: In the formula, ρ represents the material density; c p represents the material specific heat capacity; λ represents the material thermal conductivity; and T represents the material temperature. represents the volumetric heat release rate.

[0088] The boundary condition between the cladding outer surface and the coolant is: In the formula, T f represents the fluid temperature; δ u represents the half thickness of the fuel plate; δ c represents the fuel cladding thickness; and h represents the wall convection heat transfer coefficient.

[0089] S105, determine whether the key thermal parameters meet the target parameters of the current stage irradiation test, and if not, adjust the operating parameters of the next stage irradiation test.

[0090] In the embodiment, since the present application involves physical thermal analysis of irradiation tests, the target parameters of the current stage irradiation test mainly refer to temperature parameters, and the way of determining whether the key thermal parameters meet the target parameters of the current stage irradiation test belongs to a conventional technical way. The present embodiment does not make redundant description, and secondly, based on the determination result to adjust the operating parameters of the next stage irradiation test is also a conventional technical means for those skilled in the art, and the present embodiment does not make detailed description.

[0091] Based on the implementation scheme described above, it can be seen that the analysis method provided in the embodiment of the present invention first combines the burnup depth information of the metal fuel and the structural swelling model to determine the changes in the structural size and thermal conductivity of the metal fuel, and then, combines the burnup depth information to fit the burnup distribution curve of the metal fuel at the corresponding irradiation time, and uses this to perform heat release calculation to determine the heat release distribution information of the metal fuel. Finally, a sub-channel analysis model is used to analyze the heat release distribution information, structural size and thermal conductivity of the metal fuel after swelling, thereby realizing the analysis of the physical thermal parameters of the irradiation swelling process in the metal fuel pile, thereby solving the problem that the relevant technology cannot analyze the swelling of the metal fuel after irradiation test and the burnup distribution state after swelling.

[0092] Please refer to Figure 4 , Figure 4 The flowchart of the physical thermal analysis of the swelling of the gold fuel after irradiation provided by the embodiment of the present invention is as follows: Figure 4 As shown, the device includes:

[0093] The power acquisition module 310 is used to obtain the actual thermal power after the current stage of irradiation test is completed;

[0094] The parameter updating module 320 is configured to determine the burnup depth information of the metal fuel based on the measured thermal power, input the burnup depth information into a pre-configured structural swelling model for analysis, obtain the volumetric swelling ratio of the metal fuel in the axial and radial directions, update the structural dimensions of the metal fuel based on the volumetric swelling ratio, and update the thermal conductivity of the metal fuel based on the updated structural dimensions; wherein the structural dimensions refer to the axial height and radial dimensions;

[0095] The heat release distribution information calculation module 330 is used to re-fit the burnup distribution curve of the metal fuel at the corresponding irradiation time based on the burnup depth information, the updated structural dimensions of the metal fuel, and the burnup distribution calculated by the burnup management calculation model based on the deterministic method, and perform heat release calculation based on the burnup distribution curve to obtain the heat release distribution information of the metal fuel;

[0096] Thermal analysis module 340, for inputting heat release distribution information of the metal fuel, updated structural dimensions and thermal conductivity of the metal fuel into the sub-channel analysis model for thermal analysis to obtain key thermal parameters of the metal fuel;

[0097] The judgment and adjustment module 350 is used to judge whether the key thermal parameters meet the target parameters of the current stage of irradiation test. If not, the operating parameters of the next stage of irradiation test are adjusted.

[0098] It can be seen that in the physical thermal analysis of the metal fuel irradiation test provided by the embodiment of the present invention, the changes in the structural size and thermal conductivity of the metal fuel are first determined in combination with the burnup depth information and the structural swelling model of the metal fuel. Then, the burnup distribution curve of the metal fuel at the corresponding irradiation time is fitted in combination with the burnup depth information, and the heat release calculation is performed to determine the heat release distribution information of the metal fuel. Finally, the sub-channel analysis model is used to analyze the heat release distribution information, structural size and thermal conductivity of the metal fuel after swelling, thereby realizing the analysis of the physical thermal parameters of the irradiation swelling process in the metal fuel pile, thereby solving the problem that the related technology cannot analyze the swelling of the metal fuel after irradiation test and the burnup distribution state and key thermal parameters (metal fuel core temperature, etc.) after swelling.

[0099] In some embodiments, the parameter update module 320 is also used to determine the burnup depth information of the metal fuel based on the measured thermal power, specifically: the measured thermal power is input into the nuclear power estimation model for calculation to obtain the nuclear power estimation value; based on the nuclear power estimation value and the irradiation time, the burnup depth information of the metal fuel is determined.

[0100] In some embodiments, the heat release distribution information calculation module 330 is also used to determine the burnup depth information of the metal fuel based on the measured thermal power, specifically: the measured thermal power is input into the nuclear power estimation model for calculation to obtain the nuclear power estimation value; based on the nuclear power estimation value and the irradiation time, the burnup depth information of the metal fuel is determined.

[0101] In some embodiments, the burnup distribution curve corresponding to the burnup depth information when the metal fuel swells radially and / or axially is fitted by adjusting the amplitude and / or frequency of the cosine function.

[0102] Please refer to Figure 5 , Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device 400 includes a processor 410, a memory 420, a communication interface 430, and at least one communication bus for connecting the processor 410, the memory 420, and the communication interface 430. The memory 420 includes, but is not limited to, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (PROM), or a compact disc read-only memory (CD-ROM), and is used for related instructions and data.

[0103] The communication interface 430 is used to receive and send data. The processor 410 can be one or more CPUs. When the processor 410 is a CPU, the CPU can be a single-core CPU or a multi-core CPU. The processor 410 in the electronic device 400 is used to read one or more programs 421 stored in the memory 420, and perform the following operations: obtain the measured thermal power after the end of the irradiation test in the current stage; determine the burnup depth information of the metal fuel based on the measured thermal power, input the burnup depth information into a pre-configured structural swelling model for analysis, obtain the volume swelling rate of the metal fuel in the axial and radial directions, update the structural size of the metal fuel based on the volume swelling rate, and update the thermal conductivity of the metal fuel based on the updated structural size; wherein the structural size refers to the axial height and radial size; based on the burnup depth information, The updated structural dimensions of the metal fuel and the fuel consumption distribution calculated by the fuel consumption management calculation model based on the deterministic method are used to re-fit the fuel consumption distribution curve of the metal fuel under the corresponding irradiation time. The heat release calculation is performed according to the fuel consumption distribution curve to obtain the heat release distribution information of the metal fuel; the heat release distribution information of the metal fuel, the updated structural dimensions and thermal conductivity of the metal fuel are input into the sub-channel analysis model for thermal analysis to obtain the key thermal parameters of the metal fuel; it is determined whether the key thermal parameters meet the target parameters of the current stage of irradiation test. If not, the operating parameters of the next stage of irradiation test are adjusted.

[0104] It should be noted that the specific implementation of each operation can be as described above. Figure 1 The corresponding description of the method embodiment shown is that the electronic device 400 can be used to execute a metal fuel irradiation test physical thermal analysis method of the above method embodiment of the present application, which will not be described in detail here.

[0105] In an embodiment of the present disclosure, a computer-readable storage medium is also provided. The computer-readable storage medium is a memory device in a computer device, used to store programs and data. It is understood that the computer-readable storage medium herein may include both built-in storage media in the computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides storage space, which stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for being loaded and executed by a processor. These instructions may be one or more computer programs (including program code). It should be noted that the computer-readable storage medium herein may be high-speed RAM memory or non-volatile memory, such as at least one disk drive. The processor may load and execute the one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the above-described embodiment of a physical thermal analysis method for metal fuel irradiation testing. Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0106] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A physical thermal analysis method for metal fuel irradiation test, characterized in that: Methods include: Obtain the measured thermal power after the current stage of irradiation test; The burnup depth information of the metal fuel is determined based on the measured thermal power, and the burnup depth information is input into a pre-configured structural swelling model for analysis to obtain the volumetric swelling ratio of the metal fuel in the axial and radial directions. The structural dimensions of the metal fuel are updated based on the volumetric swelling ratio, and the thermal conductivity of the metal fuel is updated based on the updated structural dimensions. The structural dimensions refer to the axial height and radial dimensions. Based on the burnup depth information, the updated structural dimensions of the metal fuel, and the burnup distribution calculated using a deterministic burnup management calculation model, the burnup distribution curve of the metal fuel at the corresponding irradiation time is re-fitted. Heat release is calculated based on the burnup distribution curve to obtain the heat release distribution information of the metal fuel. Input the heat release distribution information of the metal fuel, the updated structural dimensions and thermal conductivity of the metal fuel into the sub-channel analysis model for thermal analysis to obtain the key thermal parameters of the metal fuel; Determine whether the key thermal parameters meet the target parameters of the current stage of irradiation test. If not, adjust the operating parameters of the next stage of irradiation test.

2. The method according to claim 1, characterized in that The burnup depth information of the metal fuel is determined based on the measured thermal power, specifically by inputting the measured thermal power into the nuclear power estimation model for calculation to obtain the nuclear power estimation value; Determine the burnup depth of metal fuel based on the estimated nuclear power value and irradiation time; The measured thermal power is input into a pre-configured burnup management calculation model based on deterministic methods to determine the burnup depth information of the metal fuel.

3. The method according to claim 1, characterized in that Combined with the fuel consumption distribution calculated by the fuel consumption management calculation model based on the deterministic method and the updated structural dimensions of the metal fuel, the cosine function is used to re-fit the fuel consumption distribution curve of the metal fuel under the corresponding irradiation time.

4. The method according to claim 3, characterized in that By adjusting the amplitude and / or frequency of the cosine function, the burnup distribution curve corresponding to the burnup depth information when the metal fuel swells radially and / or axially is fitted.

5. A physical thermal analysis device for metal fuel irradiation test, characterized in that: The device includes: The power acquisition module is used to obtain the measured thermal power after the current stage of irradiation test; A parameter update module is used to determine the burnup depth information of the metal fuel based on the measured thermal power, input the burnup depth information into a pre-configured structural swelling model for analysis, and obtain the volumetric swelling ratio of the metal fuel in the axial and radial directions. The structural dimensions of the metal fuel are updated based on the volumetric swelling ratio, and the thermal conductivity of the metal fuel is updated based on the updated structural dimensions. The structural dimensions refer to the axial height and radial dimensions. The heat release distribution information calculation module is used to re-fit the burnup distribution curve of the metal fuel at the corresponding irradiation time based on the burnup depth information, the updated structural dimensions of the metal fuel, and the burnup distribution calculated by the burnup management calculation model based on the deterministic method, and perform heat release calculation based on the burnup distribution curve to obtain the heat release distribution information of the metal fuel; The thermal analysis module is used to input the heat release distribution information of the metal fuel, the updated structural dimensions and thermal conductivity of the metal fuel into the sub-channel analysis model for thermal analysis to obtain the key thermal parameters of the metal fuel; The judgment and adjustment module is used to judge whether the key thermal parameters meet the target parameters of the current stage of irradiation test. If not, the operating parameters of the next stage of irradiation test are adjusted.

6. The device according to claim 5, characterized in that The parameter update module is also used to determine the burnup depth information of the metal fuel based on the measured thermal power. Specifically, the measured thermal power is input into the nuclear power estimation model for calculation to obtain the nuclear power estimation value; and the burnup depth information of the metal fuel is determined based on the nuclear power estimation value and the irradiation time.

7. The device according to claim 5, characterized in that The heat release distribution information calculation module is also used to combine the fuel consumption distribution calculated by the fuel consumption management calculation model based on the deterministic method and the updated structural dimensions of the metal fuel, and use the cosine function to re-fit the fuel consumption distribution curve of the metal fuel under the corresponding irradiation time.

8. The device according to claim 7, characterized in that The burnup distribution curve corresponding to the burnup depth information when the metal fuel swells in the radial direction and / or the axial direction is fitted by adjusting the amplitude and / or frequency of the cosine function.

9. An electronic device, characterized in that: The electronic device includes a processor, a memory, and a computer program stored in the memory and executable by the processor, wherein when the computer program is executed by the processor, the steps of the physical thermal analysis method for metal fuel irradiation testing as described in any one of claims 1 to 4 are implemented.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, wherein when the computer program is executed by a processor, the steps of the physical thermal analysis method for metal fuel irradiation testing according to any one of claims 1 to 4 are implemented.

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