Fuel rod air cavity spring irradiation heat generation rate calculation method and device and storage medium

Abstract

The invention provides a method and equipment for calculating the irradiation heat generation rate of a fuel rod air cavity spring and a storage medium, and relates to the technical field of nuclear reactors. The method comprises the steps that S1, the energy deposition rate of gamma rays in the air cavity spring at the first temperature is obtained; s2, calculating the irradiation heating rate of the air cavity spring based on the energy deposition rate, the average heat flux density of the fuel rod and the heat release share of the reactor core; s3, calculating a second temperature of the air cavity spring based on the irradiation heat generation rate; s4, judging whether the second temperature meets a preset condition or not; s5, if yes, taking the irradiation heat generation rate as a calculation result; if not, executing the step S6; and S6, taking the second temperature as a new first temperature, and repeating the steps S1 to S5. According to the method, the radiation heating rate of the fuel rod air cavity spring is calculated, and the fuel rod performance analysis and design period is shortened.

Description

Technical Field

[0001] The present application relates to the field of nuclear reactor technology, and in particular to a method, device and storage medium for calculating the radiation heating rate of a fuel rod air cavity spring. Background Art

[0002] At present, the irradiation heating rate of reactor internal components is generally obtained through high-throughput research on the heating rate measurement test of the internal materials. The irradiation heating rate of the fuel rod air cavity spring is mainly a manifestation of the energy deposited by gamma rays in the nuclear reactor in its material. It is not only an important input condition for thermal safety analysis and mechanical analysis of the internal components, but also an important parameter for the performance analysis of the fuel rod.

[0003] For reactor fuel rods, the irradiation heat rate of fuel rod air cavity springs used for fuel rod performance analysis at home and abroad is obtained by high-throughput research on the heat rate measurement test of in-pile materials. The implementation period of high-throughput research on the heat rate measurement test of in-pile materials is long, difficult, and requires a lot of funds, and the scope of application of the experimental results is limited. At present, there is no calculation method for the irradiation heat rate of fuel rod air cavity springs. Summary of the invention

[0004] In order to alleviate, mitigate or eliminate the above-mentioned technical problems, the present application provides a method, device and storage medium for calculating the radiation heating rate of the fuel rod air cavity spring, so as to realize the calculation of the radiation heating rate of the fuel rod air cavity spring and shorten the cycle of fuel rod performance analysis and design.

[0005] In a first aspect, the present application provides a method for calculating the radiation heating rate of a fuel rod air cavity spring, comprising:

[0006] Step S1, obtaining the energy deposition rate of gamma rays in the air cavity spring at a first temperature;

[0007] Step S2, calculating the radiation heating rate of the air cavity spring based on the energy deposition rate, the average heat flux density of the fuel rods and the heat release share of the core;

[0008] Step S3, calculating a second temperature of the air cavity spring based on the radiation heat generation rate;

[0009] Step S4, determining whether the second temperature meets a preset condition;

[0010] Step S5: If the conditions are met, the irradiation heating rate is used as the calculation result; if not, step S6 is executed;

[0011] Step S6: taking the second temperature as the new first temperature and repeating steps S1 to S5.

[0012] In a possible implementation, step S1 includes:

[0013] obtaining a gamma-ray energy spectrum and a nucleon density of nuclides in the air cavity spring at a first temperature;

[0014] Obtaining a reaction cross section of nuclides in the air cavity spring based on the gamma ray energy spectrum and the first temperature;

[0015] Calculating a total decay constant of the air cavity spring based on the nucleon density and the reaction cross section;

[0016] The energy deposition rate of the gamma ray in the air cavity spring is calculated based on the decay constant.

[0017] In a possible implementation, a method for obtaining the nucleon density of a nuclide in an air cavity spring at a first temperature includes:

[0018] The nucleon density of the nuclide in the air cavity spring at the first temperature is calculated based on the Avogadro constant, the molar mass of the nuclide in the air cavity spring, and the mass density of the nuclide in the air cavity spring at the first temperature.

[0019] In a possible implementation, step S2 includes:

[0020] Calculating the thermal power generated by the air cavity spring due to gamma ray irradiation based on the energy deposition rate, the average heat flux density of the fuel rods, the heat release share of the core and the surface area of ​​the air cavity spring;

[0021] The radiation heat generation rate of the air cavity spring is calculated based on the thermal power and the volume of the air cavity spring.

[0022] In a possible implementation, step S3 includes:

[0023] Obtaining the heat transfer coefficient between the adjacent core blocks of the air cavity spring and the air in the air cavity, and the total effective thermal conductivity between the coolant and the air in the air cavity;

[0024] calculating the air cavity temperature based on the heat transfer coefficient and the total effective thermal conductivity;

[0025] A second temperature of the air cavity spring is calculated based on the air cavity temperature.

[0026] In a possible implementation, obtaining the heat transfer coefficient between the adjacent core block of the air cavity spring and the air in the air cavity includes:

[0027] The heat transfer coefficient between the adjacent core blocks and the gas cavity of the gas cavity spring is calculated based on the thermal conductivity of the gas cavity, the inner diameter of the hot cladding and the Nusselt number.

[0028] In a possible implementation, a method for obtaining the total effective thermal conductivity between the coolant and the gas in the air cavity includes:

[0029] The total effective thermal conductivity between the coolant and the air cavity gas is calculated based on the thermal resistance of the air cavity gas through the boundary layer on the inner surface of the cladding, the thermal resistance of the air cavity gas through the cladding, and the thermal resistance of the air cavity gas through the boundary layer on the outer surface of the cladding.

[0030] In a possible implementation, calculating the second temperature of the air cavity spring based on the air cavity temperature includes:

[0031] The second temperature of the air cavity spring is calculated based on the following formula:

[0032]

[0033] Wherein, T2 is the second temperature of the air cavity spring, in K; T plen is the air cavity temperature, in K; Q Vsp is the radiation heating rate of the air cavity spring, in W / m 3 ; r is the radius of the air cavity spring wire, in m; h sp is the heat transfer coefficient between the air cavity spring and the air cavity, in W / m 2 K.

[0034] In a second aspect, the present application provides a computing device, including:

[0035] at least one processor; and

[0036] At least one memory having instructions stored thereon, which, when executed individually or collectively by the at least one processor, cause the computing device to perform the method according to the first aspect.

[0037] In a third aspect, the present application provides a computer storage medium having instructions stored thereon, which, when executed individually or collectively by at least one processor of a computing device, causes the computing device to execute the method described in the first aspect.

[0038] Compared with the prior art, this application has the following advantages:

[0039] The method for calculating the radiation heating rate of the fuel rod air cavity spring provided by the present application includes: step S1, obtaining the energy deposition rate of gamma rays in the air cavity spring at a first temperature; step S2, calculating the radiation heating rate of the air cavity spring based on the energy deposition rate, the average heat flux density of the fuel rod and the heat release share of the core; step S3, calculating the second temperature of the air cavity spring based on the radiation heating rate; step S4, judging whether the second temperature meets the preset conditions; step S5, if it meets the conditions, taking the radiation heating rate as the calculation result; if it does not meet the conditions, executing step S6; step S6, taking the second temperature as the new first temperature, and repeating steps S1-S5. The present application realizes the calculation of the radiation heating rate of the fuel rod air cavity spring, and can reasonably and quickly obtain the radiation heating rate of the fuel rod air cavity spring while ensuring a certain accuracy, thereby shortening the cycle of fuel rod performance analysis and design. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:

[0041] Figure 1 is a schematic structural diagram of a fuel rod provided in an embodiment of the present application;

[0042] Figure 2 It is a flow chart of a method for calculating the radiation heating rate of a fuel rod air cavity spring provided in an embodiment of the present application;

[0043] Figure 3 It is a structural diagram of a computing device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0045] As shown in this application, unless the context clearly indicates an exception, the words "a", "an", "a kind" and / or "the" do not refer to the singular, but also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0046] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0047] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. Meanwhile, it should be understood that, for ease of description, the sizes of the individual parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0048] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the outline of the component itself.

[0049] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0050] It should be understood that when a component is referred to as being “on another component,” “connected to another component,” “coupled to another component,” or “contacting another component,” it can be directly on, connected to, coupled to, or contacting the other component, or intervening components may be present. In contrast, when a component is referred to as being “directly on another component,” “directly connected to,” “directly coupled to,” or “directly contacting” another component, there are no intervening components present.

[0051] In addition, although the terms used in this application are selected from well-known and commonly used terms, some of the terms mentioned in this application specification may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0052] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, the steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0053] Figure 1 Schematic diagram of the structure of a fuel rod provided in an embodiment of the present application. Figure 1As shown, the fuel rod includes a cladding 101, and the upper and lower ports of the cladding 101 are respectively provided with an upper end plug 102 and a lower end plug 103. A plurality of fuel pellets 104 are stacked in the cladding 101. An air cavity is provided between the fuel pellet 104 and the upper end plug 102, and an air cavity spring 105 is provided in the air cavity. The axial top end of the air cavity spring 105 contacts the upper end plug 102, and the axial bottom end contacts the fuel pellet 104. The fuel pellets in direct contact with the air cavity spring 105 are referred to as adjacent pellets 1041 of the air cavity spring 105. The air cavity spring 105 has sufficient pressing force to prevent the fuel pellets 104 from being misplaced or the fuel pellets 104 from colliding with each other with the cladding 101 during transportation. In some embodiments, a support tube 106 and a support block 107 are provided between the fuel pellet 104 and the lower end plug 103 to support the stacked plurality of fuel pellets 104.

[0054] The irradiation heating rate of the air cavity spring 105 is not only an important input condition for thermal safety analysis and mechanical analysis of the reactor internal components, but also an important parameter for fuel rod performance analysis. The irradiation heating rate of the air cavity spring 105 is mainly a manifestation of the energy deposited in its material by gamma rays in a nuclear reactor.

[0055] At present, the irradiation heat rate of the fuel rod air cavity spring used for fuel rod performance analysis is obtained by high-throughput research on the heat rate measurement test of in-pile materials. The implementation period of high-throughput research on the heat rate measurement test of in-pile materials is long, difficult, and requires a lot of funds, and the application scope of the experimental results is limited. At present, there is no calculation method for the irradiation heat rate of the fuel rod air cavity spring.

[0056] Figure 2 1 is a flow chart of a method for calculating the radiation heating rate of a fuel rod air cavity spring provided in an embodiment of the present application. Figure 2 As shown in the figure, the calculation method of the radiation heating rate of the fuel rod air cavity spring includes the following contents:

[0057] Step S1, obtaining the energy deposition rate of gamma rays in the air cavity spring at a first temperature.

[0058] The first temperature T1 (in K) is a preset temperature and can be set according to actual conditions. In some embodiments, the first temperature T1 can be set to the temperature of the air cavity spring calculated without considering the radiation heat generation rate. When the radiation heat generation rate of the air cavity spring is not considered, that is, the radiation heat generation rate is zero, the temperature of the air cavity spring is equal to the air cavity temperature.

[0059] It should be noted that the energy deposition rate of gamma rays in the air cavity spring at the first temperature T1 can be stored locally offline and directly obtained from the local computer during calculation, or can be calculated and obtained in real time when calculating the radiation heating rate. In some embodiments, the method for calculating the energy deposition rate of gamma rays in the air cavity spring at the first temperature T1 includes:

[0060] Step 110: Obtain a gamma-ray energy spectrum and a nucleon density of nuclides in the air cavity spring at a first temperature.

[0061] In actual operation, the gamma ray energy spectrum E γ (in MeV) and the nucleon density J of isotope i in the air spring at the first temperature T1 i (Unit is 1 / m 3 ) is stored locally and directly obtained from the local computer during the calculation process. It can also be obtained in real time during the calculation process.

[0062] In some embodiments, the gamma ray energy spectrum E can be determined based on the type and characteristics of gamma rays in a nuclear fission reactor. γ . Confirmed gamma-ray spectrum E γ Examples are shown in Table 1.

[0063] Table 1

[0064] Gamma ray types <![CDATA[Energy spectrum E γ (MeV)]]> Share Prompt fission gamma rays 1 big Fission product decay gamma rays 1-7.6 big Capture gamma rays 1-7 big Activation product decay photons 6-7 Small

[0065] The material of the air cavity spring generally includes multiple nuclides. In some embodiments, the material of the air cavity spring is stainless steel, which is doped with other nuclides in addition to Fe. For example, 302 stainless steel generally considers three nuclides: Cr, Ni and Fe.

[0066] In some embodiments, the nucleon density of the nuclide in the air cavity spring at the first temperature can be calculated based on the Avogadro constant, the molar mass of the nuclide in the air cavity spring, and the mass density of the nuclide in the air cavity spring at the first temperature. For example, the nucleon density J of the nuclide i in the air cavity spring at the first temperature T1 is i The calculation formula is as follows:

[0067]

[0068] in,

[0069] N A : Avogadro constant, 6.02×10 23 / mol.

[0070] M i : The molar mass of isoclide i in the air cavity spring, in g / mol.

[0071] ρ i (T1): mass density of isotope i in the air cavity spring at temperature T1, in g / m 3 .

[0072] Step 120: Obtain a reaction cross section of the nuclide in the air cavity spring based on the gamma ray energy spectrum and the first temperature.

[0073] For example, the nuclear database CENDL can be queried to obtain the nuclide i and gamma-ray energy spectrum E in the air cavity spring. γ Reaction cross section σ related to the first temperature T1 i (Unit: m 2 ). Among them, the CENDL nuclear database is an important nuclear data resource developed and maintained by the China Nuclear Data Center. It is one of the five internationally recognized nuclear databases (ENDF / B in the United States, JENDL in Japan, JEF in Europe, and BROND in Russia).

[0074] Step 130: Calculate the total decay constant of the air cavity spring based on the nucleon density and the reaction cross section.

[0075] In some embodiments, the total decay constant λ (in 1 / m) of the air cavity spring may be calculated according to the following formula:

[0076]

[0077] Where n is the total number of nuclides in the air cavity spring material.

[0078] Step 140: Calculate the energy deposition rate of the gamma ray in the air cavity spring based on the decay constant.

[0079] In some embodiments, the energy deposition rate B (constant, dimensionless) of gamma rays in the air cavity spring may be calculated based on the gamma ray intensity attenuation theory. The specific calculation formula is as follows:

[0080] B=1-e -λt

[0081] Where t is the thickness of the air spring that the gamma ray passes through, in meters.

[0082] Step S2, calculating the radiation heating rate of the air cavity spring based on the energy deposition rate, the average heat flux density of the fuel rods and the heat release share of the core.

[0083] In some embodiments, step S2 specifically includes:

[0084] Step 210: Calculate the thermal power generated by the air cavity spring due to gamma ray irradiation based on the energy deposition rate, the average heat flux density of the fuel rods, the heat release share of the core, and the surface area of ​​the air cavity spring.

[0085] In some embodiments, the average heat flux density Q of the fuel rod can be used to calculate the heat flux density Q of the fuel rod. Srod (Unit: W / m 2 ) and the core heat release fraction A (a constant related to the reactor design, usually 97.5% in a pressurized water reactor and 96% in a boiling water reactor) to calculate the average gamma ray heat flux Q Sγ (Unit: W / m2 ), and then based on the average gamma-ray heat flux density Q Sγ Calculate the radiation heating rate Q of the air cavity spring by using the energy deposition rate B Vsp (Unit: W / m 3 ). For example, the radiation heating rate Q Vsp The calculation formula is as follows:

[0086] Q Sγ =(1-A)Q Srod

[0087] Among them, (1-A) can be called the heat release share of gamma rays.

[0088] In this embodiment, the energy deposition rate B and the average heat flux density Q of the gamma rays can be used to calculate the energy deposition rate B and the average heat flux density Q of the gamma rays. Sγ Calculation of the heat power Q generated by the air cavity spring due to gamma ray irradiation sp (Unit: W). For example, the heat power Q generated by the air cavity spring due to gamma ray irradiation is sp The calculation formula is as follows:

[0089] Q sp =Q Sγ SB

[0090] The radius r (unit: m) and surface area S (unit: m) of the air cavity spring wire 2 ) and volume V(m 3 ) have the following relationship:

[0091] S=2πrL

[0092] V=πr 2 L

[0093]

[0094] Wherein, L is the length of the air cavity spring wire, in m.

[0095] Step 220: Calculate the radiation heating rate of the air cavity spring based on the thermal power and the volume of the air cavity spring.

[0096] In some embodiments, the radiation heating rate Q of the air cavity spring can be calculated according to the following formula: Vsp :

[0097]

[0098] Step S3: calculating the second temperature of the air cavity spring based on the radiation heat generation rate.

[0099] In actual operation, the irradiation heating rate Q calculated in step S2 can be VspSubstitute it into the fuel performance analysis program to calculate the second temperature T2 (in K) of the air cavity spring. The second temperature T2 of the air cavity spring can be calculated based on the energy exchange between its adjacent pellets, the air cavity spring and the air cavity gas.

[0100] For example, the calculation method of the second temperature T2 of the air cavity spring includes:

[0101] Step 310: Obtain the heat transfer coefficient between the adjacent core blocks of the air cavity spring and the air in the air cavity, and the total effective thermal conductivity between the coolant and the air in the air cavity.

[0102] In actual operation, the heat transfer coefficient h between the adjacent core block of the air cavity spring and the air cavity gas can be expressed as p (Unit: W / m 2 K), and the total effective thermal conductivity U between the coolant and the cavity gas c (Unit: W / mK) is stored locally and directly obtained from the local computer during the calculation process. It can also be obtained in real time during the calculation process.

[0103] In some embodiments, the heat transfer coefficient between the adjacent pellets of the air cavity spring and the air cavity gas can be calculated based on the thermal conductivity of the air cavity gas, the inner diameter of the hot cladding, and the Nusselt number. For example, the heat transfer coefficient between the adjacent pellets of the air cavity spring and the air cavity gas is calculated based on the McAdams flat plate laminar flow or turbulent heat transfer coefficient from the natural convection of the adjacent pellets. The calculation formula of the heat transfer coefficient between the adjacent pellets of the air cavity spring and the air cavity gas is as follows:

[0104]

[0105] in,

[0106] h p : The heat transfer coefficient between the adjacent core block and the gas in the gas cavity of the gas cavity spring, in W / m 2 K;

[0107] N u : Nusselt number;

[0108] D: inner diameter of hot cladding, in m;

[0109] k: Thermal conductivity of the gas in the air cavity, in W / mK.

[0110] For example, the Nusselt number N u The calculation formula is as follows:

[0111] Nu=C(GrPr) m

[0112] in,

[0113] G r : Glaschov number;

[0114] P r : Prandtl number. When GrPr≤2.0×10 7 When C = 0.54, m = 0.25; when GrPr> 2.0 × 10 7 When, C=0.14, m=0.33.

[0115] In some embodiments, the total effective thermal conductivity between the coolant and the air cavity gas can be calculated based on the thermal resistance of the air cavity gas passing through the boundary layer on the inner surface of the cladding, the thermal resistance of the air cavity gas passing through the cladding, and the thermal resistance of the air cavity gas passing through the boundary layer on the outer surface of the cladding. For example, the total effective thermal conductivity U between the coolant and the air cavity gas is c It can be defined as the reciprocal of the sum of each individual thermal resistance, which mainly includes three thermal resistances: a) the thermal resistance of the air cavity gas passing through the boundary layer on the inner surface of the cladding; b) the thermal resistance of the air cavity gas passing through the cladding; c) the thermal resistance of the air cavity gas passing through the boundary layer on the outer surface of the cladding. Therefore, the total effective thermal conductivity U c The calculation formula is as follows:

[0116]

[0117] in,

[0118] U c : total effective thermal conductivity between coolant and cavity gas, in W / m K;

[0119] D: inner diameter of hot cladding, in m;

[0120] h f : Boundary layer heat transfer coefficient on the inner surface of the cladding, in W / m 2 K;

[0121] D o : outer diameter of cold cladding, in m;

[0122] D i : Inner diameter of cold cladding, in m;

[0123] a: thermal diffusivity of the cladding, unit is 1 / K;

[0124] ΔT: The temperature difference between the average temperature of the cladding and the temperature for calculating thermal expansion, in K;

[0125] h DB : Heat transfer coefficient between coolant and cladding, in W / m 2 K.

[0126] Step 320 : Calculate the air cavity temperature based on the heat transfer coefficient and the total effective thermal conductivity obtained in step 310 .

[0127] In some embodiments, the air cavity temperature Tplen The calculation formula (unit: K) is as follows:

[0128]

[0129] in,

[0130] T plen : air cavity temperature, in K;

[0131] Q Vsp : The heating rate of the air cavity spring due to gamma ray irradiation, that is, the irradiation heating rate of the air cavity spring, the unit is W / m 3 ;

[0132] V s : The volume of the air spring, in m 3 .

[0133] V p : air cavity volume, in m 3 ;

[0134] T BLK : The coolant temperature at the corresponding height of the air cavity spring, in K;

[0135] T pa : The temperature of the adjacent core block, in K.

[0136] Step 330: Calculate a second temperature of the air cavity spring based on the air cavity temperature.

[0137] In some embodiments, the second temperature T2 (in K) of the air cavity spring is calculated according to the following formula:

[0138]

[0139] in,

[0140] T2: The second temperature of the air cavity spring, in K;

[0141] T plen : air cavity temperature, in K;

[0142] Q Vsp : Radiation heating rate of air cavity spring, unit is W / m 3 ;

[0143] r: radius of the air cavity spring wire, in m;

[0144] h sp : Heat transfer coefficient between the air cavity spring and the air cavity, in W / m 2 K. In the actual calculation process, h sp =h p .

[0145] Step S4: determine whether the second temperature meets a preset condition.

[0146] In some embodiments, it can be determined whether the second temperature reaches a preset value, or the first temperature and the second temperature are compared. If the second temperature is equal to the first temperature, or the difference between the two is within a preset range, the second temperature meets the preset condition, otherwise the second temperature does not meet the preset condition.

[0147] Step S5: If the conditions are met, the irradiation heating rate is used as the calculation result; if not, execute step S6.

[0148] Step S6: taking the second temperature as the new first temperature and repeating steps S1 to S5.

[0149] The above embodiment proposes a method for calculating the radiation heating rate of the fuel rod air cavity spring, through which the radiation heating rate of the fuel rod air cavity spring can be reasonably and quickly obtained while ensuring a certain accuracy, thereby shortening the fuel rod performance analysis and design cycle. Due to the use of theoretical calculation, its scope of application is universal.

[0150] Figure 3 Schematic diagram of a computing device provided in an embodiment of the present application. Figure 3 As shown, computing device 500 includes one or more processors 510 , one or more memories 520 coupled to processor 510 , and one or more communication modules 540 coupled to processor 510 .

[0151] The communication module 540 is used for two-way communication. The communication module 540 has at least one antenna to facilitate communication. The communication interface may represent any interface necessary for communicating with other network elements.

[0152] Processor 510 may be of any type suitable for the local technology network, and may include, as non-limiting examples, one or more of: a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Computing device 500 may have multiple processors, such as application specific integrated circuit chips, which are driven in time to a clock that synchronizes a master processor.

[0153] The memory 520 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 524, electrically programmable read-only memory (EPROM), flash memory, hard disk, compact disk (CD), digital video disk (DVD), and other magnetic and / or optical memories. Examples of volatile memories include, but are not limited to, random access memory (RAM) 522 and other volatile memories that do not persist during the duration of a power outage.

[0154] Computer program 530 includes computer executable instructions executed by associated processor 510. Program 530 may be stored in ROM 524. Processor 510 may perform any appropriate actions and processes by loading program 530 into RAM 522.

[0155] The embodiment of the present application can be implemented by program 530, so that the computing device 500 can execute the reference Figure 2 Any process disclosed in the discussion. The embodiments of the present application may also be implemented by hardware or by a combination of software and hardware.

[0156] In some embodiments, program 530 may be tangibly embodied in a computer-readable medium, which may be contained in computing device 500 (e.g., memory 520) or other storage devices accessible to computing device 500. Computing device 500 may load program 530 from the computer-readable medium to RAM 522 for execution. The computer-readable medium may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. The computer-readable medium has program 530 stored thereon.

[0157] Generally, various embodiments of the present application may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Certain aspects may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be performed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present application are shown and described as block diagrams, flow charts, or using some other graphical representations, it should be understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general hardware or controllers or other computing devices, or some combination thereof.

[0158] The present application also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer executable instructions, such as instructions included in program modules, which are executed in a device on a target real or virtual processor to perform the above-mentioned reference Figure 2The method described. Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functions of program modules can be combined or separated between program modules as needed. Machine executable instructions for program modules can be executed in local or distributed devices. In distributed devices, program modules can be located in local and remote storage media.

[0159] The program code for executing the method of the present application can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing equipment so that when the program code is executed by the processor or controller, the function / operation specified in the flow chart and / or the block diagram is realized. The program code can be executed completely on the machine as an independent software package, partially on the machine, partially on the machine, partially on a remote machine, partially on a remote machine, or all on a remote machine or server.

[0160] In the context of this application, computer program codes or related data may be carried by any appropriate carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of carriers include signals, computer readable media, etc.

[0161] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer readable medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or apparatuses, or any suitable combination of the foregoing. More specific examples of computer readable storage media include an electrical connection with one or more wires, a portable computer floppy disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0162] In addition, although the operations are described in a specific order, this should not be construed as requiring to perform these operations in the specific order or sequence shown, or to perform all the operations shown, to obtain the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these details should not be interpreted as limiting the scope of the application, but can be interpreted as a description of the specific features of a particular embodiment. Some of the features described in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination.

[0163] Although the present application has been described in language specific to structural features and / or methodological acts, it should be understood that the present application defined in the appended claims is not necessarily limited to the specific features or acts described above. Instead, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A method for calculating the radiation heating rate of a fuel rod air cavity spring, characterized in that: include: Step S1, obtaining the energy deposition rate of gamma rays in the air cavity spring at a first temperature; Step S2, calculating the radiation heating rate of the air cavity spring based on the energy deposition rate, the average heat flux density of the fuel rods and the heat release share of the core; Step S3, calculating a second temperature of the air cavity spring based on the radiation heat generation rate; Step S4, determining whether the second temperature meets a preset condition; Step S5: If the conditions are met, the irradiation heating rate is used as the calculation result; if not, step S6 is executed; Step S6: taking the second temperature as the new first temperature and repeating steps S1 to S5.

2. The method according to claim 1, characterized in that Step S1 includes: obtaining a gamma-ray energy spectrum and a nucleon density of nuclides in the air cavity spring at a first temperature; Obtaining a reaction cross section of nuclides in the air cavity spring based on the gamma ray energy spectrum and the first temperature; Calculating a total decay constant of the air cavity spring based on the nucleon density and the reaction cross section; The energy deposition rate of the gamma ray in the air cavity spring is calculated based on the decay constant.

3. The method according to claim 2, characterized in that The method for obtaining the nucleon density of the nuclide in the air cavity spring at the first temperature includes: The nucleon density of the nuclide in the air cavity spring at the first temperature is calculated based on the Avogadro constant, the molar mass of the nuclide in the air cavity spring, and the mass density of the nuclide in the air cavity spring at the first temperature.

4. The method according to claim 1, characterized in that Step S2 includes: Calculating the thermal power generated by the air cavity spring due to gamma ray irradiation based on the energy deposition rate, the average heat flux density of the fuel rods, the heat release share of the core and the surface area of ​​the air cavity spring; The radiation heat generation rate of the air cavity spring is calculated based on the thermal power and the volume of the air cavity spring.

5. The method according to claim 1, characterized in that Step S3 includes: Obtaining the heat transfer coefficient between the adjacent core blocks of the air cavity spring and the air in the air cavity, and the total effective thermal conductivity between the coolant and the air in the air cavity; calculating the air cavity temperature based on the heat transfer coefficient and the total effective thermal conductivity; A second temperature of the air cavity spring is calculated based on the air cavity temperature.

6. The method according to claim 5, characterized in that Obtaining the heat transfer coefficient between the adjacent core block and the cavity gas of a gas cavity spring includes: The heat transfer coefficient between the adjacent core blocks and the gas cavity of the gas cavity spring is calculated based on the thermal conductivity of the gas cavity, the inner diameter of the hot cladding and the Nusselt number.

7. The method according to claim 5, characterized in that Methods for obtaining the total effective thermal conductivity between the coolant and the cavity gas include: The total effective thermal conductivity between the coolant and the air cavity gas is calculated based on the thermal resistance of the air cavity gas through the boundary layer on the inner surface of the cladding, the thermal resistance of the air cavity gas through the cladding, and the thermal resistance of the air cavity gas through the boundary layer on the outer surface of the cladding.

8. The method according to claim 5, characterized in that Calculating the second temperature of the air cavity spring based on the air cavity temperature comprises: The second temperature of the air cavity spring is calculated based on the following formula: Wherein, T2 is the second temperature of the air cavity spring, in K; T plen is the air cavity temperature, in K; Q Vsp is the radiation heating rate of the air cavity spring, in W / m 3 ; r is the radius of the air cavity spring wire, in m; h sp is the heat transfer coefficient between the air cavity spring and the air cavity, in W / m 2 K.

9. A computing device, characterized in that include: at least one processor; as well as At least one memory having instructions stored thereon, which, when executed individually or collectively by the at least one processor, cause the computing device to perform the method according to any one of claims 1 to 8.

10. A computer storage medium, characterized in that: The computer storage medium stores instructions, which, when executed individually or collectively by at least one processor of a computing device, cause the computing device to perform the method according to any one of claims 1 to 8.

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