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

Abstract

The invention discloses a metal fuel irradiation test physical and thermal analysis method, device, equipment and medium, and relates to the field of nuclear reactor physics and thermal engineering, the method comprises the following steps: determining burnup depth information of metal fuel according to actually measured thermal power, inputting the burnup depth information into a pre-configured structure swelling model for analysis, and determining the burnup depth information of the metal fuel according to the burnup depth information; the volume swelling rate of the metal fuel in the axial direction and the radial direction is obtained, the structural size of the metal fuel is updated according to the volume swelling rate, and the heat conductivity of the metal fuel is updated according to the updated structural size; according to the burnup depth information, the updated structure size of the metal fuel and the burnup distribution condition obtained through calculation of a burnup management calculation model based on a deterministic theory method, a burnup distribution curve of the metal fuel under the corresponding irradiation time is re-fitted, and heat release calculation is conducted according to the burnup distribution curve; obtaining heat release distribution information of the metal fuel; and inputting the heat release distribution information of the metal fuel, the updated structure size of the metal fuel and the heat conductivity into the sub-channel analysis model for thermotechnical analysis to obtain key thermotechnical parameters of the metal fuel.

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 test. Background Art

[0002] For the metal fuel irradiation test, the irradiation test fuel rod adopts the structural design of annular core + liquid sodium. In the early irradiation test, the effective density of the annular core was ~85%. With the accumulation of test data, the relationship between the fission gas release rate and the swelling of the fuel core was summarized. When the swelling caused by fission gas is close to 30%, the fission gas of the fuel core will be released into the cavity above the fuel core under the action of bubble connection, thereby hollowing out the fuel structure near the cladding, thereby 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 will reach ~33%. This swelling is conducive to the release of most fission gases. Therefore, the effective density design of ~75% was adopted in the later MARK-II, EBR-II, and IFR related irradiation short rod designs.

[0003] During the irradiation process of metal alloy fuel, it is necessary to consider the influence of multiple factors such as irradiation dose, temperature, alloy composition, etc. on swelling, and conduct a comprehensive analysis of multiple factors to obtain more accurate swelling calculation results. At present, related technologies apply multi-physics coupling calculations to the numerical simulation of metal fuels. For example, CASL integrates existing core design and analysis technologies to carry out coupled multi-physics, multi-process, multi-dimensional, and multi-scale reactor numerical simulations, but the amount of numerical simulation calculations of this technology is very large. At present, related technologies also propose numerical fuel rod models based on tight multi-physics coupling calculations, which have independent heat conduction, mechanics, and neutron transport calculation modules, and have developed the numerical fuel rod program YUAN. However, the above are mainly aimed at numerically simulating swelling behavior, fuel consumption changes, and temperature field distribution of known metal fuels. For metal fuels subjected to in-pile irradiation tests, the swelling behavior of metal fuels after irradiation tests (such as axial and radial swelling of metal fuels) and stress changes are all in the research and development stage, and cannot be analyzed using the related technologies described above.

[0004] Therefore, how to analyze the swelling of metal fuel after irradiation test and the fuel consumption distribution after swelling is an urgent problem 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 the metal fuel after irradiation test and the fuel consumption distribution state after swelling.

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

[0007] Obtain the measured thermal power after the current stage of irradiation test;

[0008] The burnup depth information of the metal fuel is determined according to 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, and the structural size of the metal fuel is updated according to the volume swelling rate, and the thermal conductivity of the metal fuel is updated according to the updated structural size; wherein the structural size refers to the axial height and radial size;

[0009] According to 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, the burnup distribution curve of the metal fuel at the corresponding irradiation time is refitted, and the heat release calculation is performed according to the burnup distribution curve to obtain the heat release distribution information of the metal fuel;

[0010] 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;

[0011] 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.

[0012] In one implementation, the burnup depth information of the metal fuel is determined according to 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;

[0013] The burnup depth information of the metal fuel is determined based on the estimated nuclear power value and irradiation time.

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

[0015] In one implementation, 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 are combined, and the cosine function is used to re-fit the fuel consumption distribution curve of the metal fuel at the corresponding irradiation time.

[0016] 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.

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

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

[0019] A parameter updating module is used to determine the burnup depth information of the metal fuel according to 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 dimensions of the metal fuel according to the volume swelling rate, and update the thermal conductivity of the metal fuel according to the updated structural dimensions; wherein the structural dimensions refer to the axial height and radial dimensions;

[0020] The heat release distribution information calculation module is used to refit the burnup distribution curve of the metal fuel at the corresponding irradiation time according to 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 according to the burnup distribution curve to obtain the heat release distribution information of the metal fuel;

[0021] Thermal analysis module, used to input the heat release distribution information of metal fuel, the updated structural dimensions and thermal conductivity of metal fuel into the sub-channel analysis model for thermal analysis, and obtain the key thermal parameters of 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; based on the nuclear power estimation value and the irradiation time, the burnup depth information of the metal fuel is determined.

[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 at 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 end of the current stage of irradiation test is obtained; the burnup depth information of the metal fuel is determined according to 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, and the structural size of the metal fuel is updated according to the volume swelling rate, and the thermal conductivity of the metal fuel is updated according to 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 according to the burnup depth information, and the heat release is calculated according to 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 fits the burnup distribution curve of the metal fuel at the corresponding irradiation time in combination with the burnup depth information, 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 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. 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 test 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 principle block diagram of a physical thermal analysis device for metal fuel irradiation testing provided by an embodiment of the present invention;

[0035] Figure 5 A schematic diagram of the structure 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 embodiments and drawings. The exemplary embodiments of the present invention and their description 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 function, operation or element applied for, 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 a combination 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 a combination of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or a combination 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 combination or all combinations of the words listed at the same time. 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 diagram of a process flow of a physical thermal analysis method for metal fuel irradiation test provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, the method includes:

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

[0041] In this embodiment, the thermal power calculation formula is as follows: 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] There are thermocouples at the inlet and outlet of the irradiator to measure the coolant temperature, and a flow meter at the inlet of the irradiator to measure the coolant flow. The inlet and outlet pressures of the irradiator use the inlet and outlet pressure data of the reactor core. According to the average temperature and pressure of the coolant, the water and steam property calculation software of the IAPWS-IF97 standard is used to query the corresponding constant pressure specific heat capacity. The measured thermal power can be obtained by combining the above measurement data with the above formula.

[0043] S102, determining the burnup depth information of the metal fuel according to the measured thermal power, inputting the burnup depth information into a pre-configured structural swelling model for analysis, obtaining the volume swelling rate of the metal fuel in the axial and radial directions, updating the structural dimensions of the metal fuel according to the volume swelling rate, and updating the thermal conductivity of the metal fuel according to the updated structural dimensions; wherein the structural dimensions refer to the axial height and radial dimensions.

[0044] Specifically, metal fuel is the core component of nuclear reactors, and its performance directly affects the safety and economy of the reactor. Structural swelling is a common problem of metal fuel during irradiation, which will cause changes in the size of fuel elements, thereby affecting the power distribution and burnup management of the reactor.

[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, in the nuclear power estimation model, the measured thermal power is deducted from the deposition energy of the reactor in the irradiation device, and then divided by the correction coefficient to obtain the estimated nuclear power value. The thermal power includes the deposition energy of the reactor in the irradiation device, which needs to be deducted to obtain the energy generated by the fission of the metal fuel deposited on the irradiation device, and then divided by the correction coefficient to obtain the total energy generated by the fission of the metal fuel (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 building a Monte Carlo model.

[0048] According to the metal fuel nuclear power P N (MW), as well as the number of days of irradiation test T(d) and the initial uranium load M(t), the nuclear fuel burnup (MWd / tU) can be calculated, 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 method 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 change in the number of nuclides over time. It is based on the principle of mass conservation and takes into account the generation and disappearance rates of nuclides. By solving the burnup equation, we can obtain the change in the number of each nuclide in the reactor 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 nuclear density budget value, and then the core is calculated to obtain the neutron injection rate, and the neutron injection rate is used to calculate the average neutron injection rate. Finally, the average neutron injection rate is used to calculate A1, A2, F1 and C1, and A1, A2, F1 and C1 are substituted into the burnup equation for solution to obtain the corrected nuclear density. Therefore, it can be seen that correcting the burnup can improve the accuracy of the core diffusion calculation.

[0056] Neutron Fluence Rate Distribution: Neutron fluence rate distribution is the spatial distribution of neutron density in the reactor. It determines the nuclear reaction rate in various places in the reactor, thereby affecting the production and consumption of nuclides. In the burnup management calculation model, it is necessary to accurately calculate the neutron fluence rate distribution to obtain accurate burnup results. It should be noted that the calculation of neutron fluence rate is a conventional technical means, and this embodiment will not be described in detail.

[0057] Reactivity control: Reactivity control is the key to maintaining stable operation of the reactor. During the operation of the reactor, the reactivity will change due to changes in fuel consumption and core power distribution. Therefore, it is necessary to maintain the stability of reactivity by adjusting the control parameters of the reactor (such as the position of absorber components such as control rods, etc.).

[0058] Fuel assembly parameters: Fuel assembly structure, fuel enrichment, element diameter, cladding thickness and other parameters will affect the reactor burnup process. In the burnup management calculation model, these parameters need to be accurately input to obtain accurate burnup results.

[0059] Furthermore, the main mechanisms of metal fuel structural swelling include the release and aggregation of fission gases, grain boundary migration and pore formation. When metal fuel is irradiated, a large amount of fission gases will be produced. These gases gather in the fuel through the diffusion movement of atoms at high temperatures and form bubbles. As the bubbles continue to grow and increase in number, they will gather on the grain boundaries, eventually causing the swelling of the fuel.

[0060] The construction of the swelling model of the metal fuel structure usually needs to consider the following key factors: Generation and release of fission gas: It is necessary to accurately calculate the generation rate and release mechanism of fission gas, as well as their diffusion and aggregation process in the fuel. Material properties: including physical properties such as thermal expansion coefficient, elastic modulus, yield strength of the fuel, and compatibility of the fuel with the cladding material. Irradiation conditions: including irradiation dose, irradiation temperature, irradiation time, etc. These factors will affect the swelling behavior of the fuel. Swelling amount calculation: Based on the above factors, the swelling amount of the fuel is calculated by mathematical models or finite element simulation methods.

[0061] Therefore, the burnup depth information of the metal fuel is determined based on the burnup management calculation model of the deterministic method, and the burnup depth information is input into the pre-configured structural swelling model for analysis to obtain the volume swelling rate of the metal fuel in the axial and radial directions after the irradiation test. Then, based on the volume swelling rate in the axial and radial directions, that is, the structural size of the metal fuel, the thermal conductivity of the metal fuel can be updated according to the updated structural size.

[0062] Specifically, after the metal fuel swells due to irradiation, its core height and radial dimensions will change, and the internal atomic density distribution will also change. Based on the solution of the deterministic diffusion equation, the method of mixing the core material cross-sectional parameters with the gas cross-sectional parameters inside the annular core is adopted to deal with the uneven physical properties of the material and the large gradient of the thermal neutron flux near the interface, which has more accurate estimation and calculation accuracy. In the actual calculation process, the physical model of the metal fuel irradiation device has been fixedly divided into grids, and the change of the metal fuel nuclear power after swelling will be reflected through the change of macroscopic cross-sectional parameters. Therefore, in order to cope with the change of cross-sectional parameters after metal swelling, a macroscopic cross-sectional library is established. According to the swelling data in the literature, the swelling structure and burnup distribution under the corresponding atomic burnup are established in advance (processed by the following method), and then the cross-sectional production program (such as HELIOS) is used to make the above into the corresponding small group cross-sectional parameters of the fuel management program. According to the burnup information calculated in the fuel management program, the cross-sectional library is called to realize the heat release tracking calculation and verification 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, axial volume swelling and burnup of metal fuel. Since the total swelling of metal fuel can be divided into two parts, namely, the swelling caused by solid fission products and gas:

[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 by 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 content.

[0073] S103, fitting a burnup distribution curve of the metal fuel at a 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 above-mentioned fuel consumption information is fuel consumption depth information obtained by inverting the thermal power measurement value, which deviates from the calculated value obtained by the fuel consumption management calculation model based on the deterministic method. Since the fuel consumption distribution information obtained by the calculation model is more detailed, the fuel consumption depth calculated by the measured value is used as the standard, and the detailed fuel consumption distribution obtained by the calculation model is corrected, that is, it is corrected according to the proportion: The corrected fuel consumption distribution curve is fitted, and then the fuel consumption distribution curve is refitted according to the changes in the metal fuel structure size. According to the new fuel consumption 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 distribution of burnup after metal swelling is even more difficult to track and predict, for most metal irradiation tests, how to deal with metal swelling and the distribution of burnup after swelling is the difficulty of irradiation test. At present, for the behavior of metal swelling in the scientific research stage, reference literature data is used. For the burnup distribution curve after swelling, the following method is used for processing:

[0076] According to 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, and its basic form is as follows: Y = C0 + A·cos(π·(xx c ) / w), where C0 is the intercept, A is the amplitude, x is the axial height, and w is 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 and only the axial swelling is considered. By adjusting the frequency w 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 to replace the reduction of fission atom density after core swelling and the influence of changes in core axial fuel consumption information on linear power density. That is, by simulating the dynamic changes of cosine waveforms, under the premise of ensuring that the area within a wavelength remains unchanged, the fuel consumption distribution information is adjusted according to the change law of peak and wavelength, and then the axial linear power distribution of the core is recalculated and analyzed, so as to more accurately determine the fuel consumption distribution curve of the metal fuel.

[0083] S104, inputting 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 key thermal parameters of the metal fuel.

[0084] In this embodiment, the subchannel analysis model is a method of dividing the coolant flow channel in the fuel assembly into multiple interconnected and interacting small channels (i.e., subchannels). There is an exchange or transfer of coolant mass, momentum, and energy between these subchannels, i.e., mixing. By listing the coolant mass, energy, and momentum conservation equations for all subchannels separately, and solving them simultaneously using appropriate boundary conditions or initial condition types, 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) describing the flow and heat transfer of coolant in the irradiation device are as follows:

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

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

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

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

[0090] In this embodiment, since the present invention involves the physical thermal analysis of irradiation test, the target parameters of the irradiation test at the current stage mainly refer to the temperature parameters. The method of judging whether the key thermal parameters meet the target parameters of the irradiation test at the current stage belongs to the conventional technical method, and this embodiment does not make redundant explanations. Secondly, adjusting the operating parameters of the next stage of irradiation test based on the judgment results is also a conventional technical means for technicians in this technical field, and this embodiment does not make a 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 and the structural swelling model of the metal fuel to determine the changes in the structural size and thermal conductivity of the metal fuel, and then fits the burnup distribution curve of the metal fuel at the corresponding irradiation time in combination with the burnup depth information, 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 related 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 A flowchart of the physical thermal analysis of the swelling of the gold fuel after irradiation provided by the embodiment of the present invention is shown in FIG. Figure 4 As shown, the device comprises:

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

[0094] The parameter updating module 320 is used to determine the burnup depth information of the metal fuel according to the measured thermal power, input the burnup depth information into the 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 according to the volume swelling rate, and update the thermal conductivity of the metal fuel according to the updated structural size; wherein the structural size refers to the axial height and radial size;

[0095] The heat release distribution information calculation module 330 is used to refit the burnup distribution curve of the metal fuel at the corresponding irradiation time according to 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 according to the burnup distribution curve to obtain the heat release distribution information of the metal fuel;

[0096] Thermal analysis module 340, used for inputting 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 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 irradiation test in the current stage. If not, the operating parameters of the irradiation test in the next stage are adjusted.

[0098] It can be seen that in the physical thermal analysis of the metal fuel irradiation test provided in 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 updating module 320 is also used to determine the burnup depth information of the metal fuel based on the measured thermal power, specifically: inputting the measured thermal power into the nuclear power estimation model for calculation to obtain the nuclear power estimation value; and determining the burnup depth information of the metal fuel based on the nuclear power estimation value and the irradiation time.

[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 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 portable CD-ROM, and the memory 420 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, and input the burnup depth information 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, update the structural dimensions of the metal fuel based on the volume swelling rate, 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; 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 refit the fuel consumption distribution curve of the metal fuel at the corresponding irradiation time, and 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 Figure 1 According to the corresponding description of the method embodiment shown, the electronic device 400 can be used to execute a physical thermal analysis method for metal fuel irradiation test of the above method embodiment of the present application, which will not be described in detail here.

[0105] In the embodiments of the present disclosure, a computer-readable storage medium is also provided, and the computer-readable storage medium is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both the built-in storage medium in the computer device and the extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory (non-volatile memory), such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the above-mentioned embodiment of a physical thermal analysis method for metal fuel irradiation test. Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete 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 according to 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, and the structural size of the metal fuel is updated according to the volume swelling rate, and the thermal conductivity of the metal fuel is updated according to the updated structural size; wherein the structural size refers to the axial height and radial size; According to 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, the burnup distribution curve of the metal fuel at the corresponding irradiation time is refitted, and the heat release calculation is performed according to 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 according to 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; The burnup depth information of the metal fuel is determined based on the estimated nuclear power value and irradiation time. The measured thermal power is input into the pre-configured burnup management calculation model based on the deterministic method 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 at 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, a 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 actual thermal power after the irradiation test in the current stage; A parameter updating module is used to determine the burnup depth information of the metal fuel according to 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 dimensions of the metal fuel according to the volume swelling rate, and update the thermal conductivity of the metal fuel according to the updated structural dimensions; wherein the structural dimensions refer to the axial height and radial dimensions; The heat release distribution information calculation module is used to refit the burnup distribution curve of the metal fuel at the corresponding irradiation time according to 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 according to the burnup distribution curve to obtain the heat release distribution information of the metal fuel; Thermal analysis module, used to input the heat release distribution information of metal fuel, the updated structural dimensions and thermal conductivity of metal fuel into the sub-channel analysis model for thermal analysis, and obtain the key thermal parameters of 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 updating module is also used to determine the burnup depth information of the metal fuel based on the measured thermal power, specifically: input the measured thermal power into the nuclear power estimation model for calculation to obtain the nuclear power estimation value; and determine the burnup depth information of the metal fuel 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 at 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 radially and / or axially 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 a 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 a physical thermal analysis method for metal fuel irradiation testing as claimed in any one of claims 1 to 4 are implemented.

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