Reactor core simulation device and preparation method thereof

Abstract

The embodiment of the invention relates to the technical field of nuclear reactor testing, in particular to a reactor core simulation device and a preparation method thereof. The reactor core simulation device comprises a container body, a first confluence piece, a second confluence piece, a heat dissipation shell piece and a plurality of electric heating pieces. The container body is used for simulating a reactor core container, and two axial ends of the container body are opened; the first confluence piece and the second confluence piece are connected with the two axial ends of the container body respectively to seal the openings in the two ends and form a body cavity together with the container body, and the first confluence piece and the second confluence piece further form a first confluence cavity and a second confluence cavity which are in fluid communication with the body cavity respectively and are used for allowing a coolant to flow; the heat dissipation shell piece and the second confluence piece jointly form a heat dissipation cavity which is in fluid communication with the second confluence cavity; and the plurality of electric heating elements are used for simulating heating of a plurality of fuel elements of the reactor core. According to the embodiment of the invention, heat is dissipated to the outside through the heat dissipation shell, so that the part, located outside the heat dissipation shell, of the electric heating piece is prevented from being broken down due to over-high temperature.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of nuclear reactor testing, and in particular to a core simulation device and a preparation method thereof. Background Art

[0002] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] With the continuous advancement of reactor research, small liquid metal-cooled nuclear reactors, due to their small size and light weight, are widely used in special application scenarios such as space, on the lunar surface, underwater, and on vehicles. To fully understand the power generation performance of the power supply and the thermal and hydraulic characteristics of the core, core simulation devices that use electric heating instead of nuclear heating are often used to simulate the core of small liquid metal-cooled nuclear reactors to obtain the core's operating characteristics under real-world conditions.

[0004] At present, there are still many limitations in the process of using core simulation devices to simulate the core of a small sodium-potassium alloy-cooled nuclear reactor to study the thermal-hydraulic characteristics of the core. Summary of the Invention

[0005] A brief overview of the present application is provided below to provide a basic understanding of certain aspects of the present application. It should be understood that this overview is not an exhaustive overview of the present application. It is not intended to identify key or important portions of the present application, nor is it intended to limit the scope of the present application. Its purpose is simply to present certain concepts in a simplified form as a prelude to the more detailed description that will be discussed later.

[0006] Embodiments of the present application provide a core simulation device and a method for preparing the same.

[0007] In a first aspect, an embodiment of the present application provides a core simulation device for simulating a core of a reactor, the core simulation device comprising: a container body, a first manifold, a second manifold, a heat dissipation shell, and a plurality of electric heating elements. The container body is used to simulate a core container, and the container body has openings at both axial ends; the first manifold and the second manifold are respectively connected to the axial ends of the container body to close the openings at both ends and form a body cavity together with the container body, wherein the first manifold and the second manifold further form a first manifold cavity and a second manifold cavity, respectively, which are in fluid communication with the body cavity for coolant flow; the heat dissipation shell and the second manifold together form a heat dissipation cavity in fluid communication with the second manifold cavity; the plurality of electric heating elements are used to simulate the heating of a plurality of fuel elements in the core, each electric heating element extending from the body cavity through the second manifold cavity and the heat dissipation cavity in sequence to the outside of the heat dissipation shell; wherein the heat dissipation shell is configured to dissipate heat to the outside to cool the portion of the electric heating element located within the heat dissipation cavity, thereby reducing the temperature of the portion of the electric heating element located outside the heat dissipation shell to below a specified temperature.

[0008] In the embodiments of the present application, a heat dissipation shell is provided, and the heat dissipation shell and the second conduit together form a heat dissipation cavity that is fluidically connected to the second conduit cavity, so that the parts of the multiple electric heating elements located in the heat dissipation cavity are dissipated, so that the temperature of the parts of the electric heating elements located outside the heat dissipation shell can be reduced to below a limited temperature, thereby avoiding the problem of malfunction of the parts of the electric heating elements located outside the heat dissipation shell due to excessive temperature, thereby ensuring the stable operation of the electric heating elements.

[0009] In addition, in an embodiment of the present application, a heat dissipation shell and a second manifold are provided to jointly form a heat dissipation cavity that is fluidically connected to the second manifold cavity, so that the electric heating element is cooled and dissipated. This allows conventional electric heating elements to be used to simulate the fuel elements of a nuclear reactor without changing the overall structure of the core.

[0010] In the second aspect, an embodiment of the present application also provides a method for preparing a core simulation device, which is used to prepare the core simulation device provided in the first aspect of the present application, and the preparation method includes: S1. Determine the diameter of the extension section of the electric heating element, the wall thickness of the tube, the gap between the extension section and the tube, and the size of the heat dissipation hole of the heat dissipation shell according to the minimum spacing between adjacent electric heating elements in the container body and the welding space requirements between the pipe and the heat dissipation shell; S2. Determine the axial length of the heat dissipation shell along the container body according to the temperature of the coolant in the second confluence cavity, the size of the second confluence cavity, the thermal conductivity of the coolant, the thermal conductivity of the heat dissipation shell, and the temperature of the external environment; S3. Assemble and weld the electric heating element, the first confluence, the container body, the second confluence, the heat dissipation shell and the pipe together.

[0011] In the embodiment of the present application, the diameter of the extension section of the electric heating element, the wall thickness of the tube, the gap between the extension section and the tube, and the size of the heat dissipation hole of the heat dissipation shell are determined according to the minimum spacing between adjacent electric heating elements in the container body and the welding space requirements between the tube and the heat dissipation shell. This can ensure that the heating sections in the main body cavity, the first confluence cavity, and the second confluence cavity are the same size as the fuel elements, thereby ensuring the reliability of the test results. It can also provide sufficient space for welding the tube and the heat dissipation shell when the gap between two adjacent electric heating elements is only 1 mm, thereby reducing the difficulty of installing the electric heating element in the core simulation device.

[0012] Furthermore, the axial length of the heat dissipation shell along the container body is determined according to the temperature of the coolant in the second confluence cavity, the size of the second confluence cavity, the thermal conductivity of the coolant, the thermal conductivity of the heat dissipation shell, and the temperature of the external environment, so that the heat dissipation shell can meet the requirement that the wires arranged outside the heat dissipation shell do not exceed the specified temperature, thereby avoiding the problem of wire failure due to excessive temperature, and ensuring that the prepared core simulation device can work stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Other objects and advantages of the present application will become apparent from the following description of the embodiments of the present application with reference to the accompanying drawings, which will help to provide a comprehensive understanding of the present application.

[0014] Figure 1 is a structural schematic diagram of a core simulation device according to one embodiment of the present application;

[0015] Figure 2 This is a flow chart of a method for preparing a core simulation device according to one embodiment of the present application.

[0016] Description of reference numerals:

[0017] 1. Reactor core simulator;

[0018] 10. Container body; 11. Body cavity;

[0019] 20. First manifold; 21. First manifold cavity; 22. First manifold plate; 23. First end plate; 24. First manifold tube;

[0020] 30. Second manifold; 31. Second manifold cavity; 32. Second manifold plate; 33. Second end plate; 34. Second manifold barrel;

[0021] 40. Heat dissipation shell; 41. Heat dissipation cavity; 42. Heat dissipation cover; 43. Heat dissipation cylinder;

[0022] 50. Electric heating element; 51. Heating section; 52. Heat dissipation section; 53. Extension section; 54. Wire;

[0023] 60. Pipe fittings;

[0024] 70. First coolant interface;

[0025] 80. Second coolant interface.

[0026] It should be noted that the drawings are not necessarily drawn to scale, but are merely shown in a schematic manner that does not affect the reader's understanding. DETAILED DESCRIPTION

[0027] Exemplary embodiments of the present application will be described below with reference to the accompanying drawings. For the sake of clarity and conciseness, not all features of actual implementations are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the process of developing any such actual implementation in order to achieve the developer's specific goals, such as meeting those constraints related to the system and business, and these constraints may vary depending on the implementation. In addition, it should be understood that although the development work may be very complex and time-consuming, it is a routine task for those skilled in the art who benefit from the content of this application.

[0028] It is also necessary to explain here that, in order to avoid obscuring the present application due to unnecessary details, the accompanying drawings only show the device structure and / or processing steps that are closely related to the solution according to the present application, while other details that are not closely related to the present application are omitted.

[0029] Currently, the core temperatures of nuclear reactors using liquid metal cooling are relatively high, typically reaching 500-600°C, or even above 1000°C. To best capture the core's operating characteristics under real-world conditions, the operating temperature of the electric heating elements in the core simulation device must also be consistent with the core's actual temperature. The inventors of this application have discovered that the design temperature of the terminal materials for the electric heating elements in current core simulation devices is typically lower than this temperature range, making it difficult to stably perform core simulation using existing electric heating elements.

[0030] Based on this, an embodiment of the present application provides a core simulation device for stably simulating the core of a reactor.

[0031] Figure 1 FIG. 1 is a schematic structural diagram of a core simulation device 1 according to an embodiment of the present application. Figure 1As shown, the core simulation device 1 includes: a container body 10, a first manifold 20, a second manifold 30, a heat dissipation shell 40 and a plurality of electric heating elements 50. The container body 10 is used to simulate the core container, and the axial ends of the container body 10 are open; the first manifold 20 and the second manifold 30 are respectively connected to the axial ends of the container body 10 to close the openings at both ends and form a body cavity 11 together with the container body 10, wherein the first manifold 20 and the second manifold 30 also form a first manifold cavity 21 and a second manifold cavity 31 respectively in fluid communication with the body cavity 11 for coolant flow; the heat dissipation shell 40 and the second manifold 30 together form a fluid communication with the second manifold cavity 31 The heat dissipation cavity 41; multiple electric heating elements 50 are used to simulate the heat generation of multiple fuel elements of the core, and each electric heating element 50 extends from the main body cavity 11 through the second confluence cavity 31 and the heat dissipation cavity 41 to the outside of the heat dissipation shell 40; wherein the heat dissipation shell 40 is configured to dissipate heat to the outside, so as to cool the portion of the electric heating element 50 located in the heat dissipation cavity 41, so that the temperature of the portion of the electric heating element 50 located outside the heat dissipation shell 40 (such as the wire 54 and the wire sealing material mentioned below) can be reduced to below a specified temperature.

[0032] In the embodiment of the present application, a heat dissipation shell 40 is provided, and the heat dissipation shell 40 and the second confluence member 30 jointly form a heat dissipation cavity 41 that is fluidically connected to the second confluence cavity 31, so as to dissipate heat from the parts of the multiple electric heating elements 50 located in the heat dissipation cavity 41, so that the temperature of the parts of the electric heating elements 50 located outside the heat dissipation shell 40 can be reduced to below a specified temperature, thereby avoiding the problem of malfunction of the parts of the electric heating elements 50 located outside the heat dissipation shell 40 due to excessive temperature, thereby ensuring stable operation of the electric heating elements 50.

[0033] Since the heat dissipation cavity 41 is located on the side of the second confluence cavity 31 away from the main cavity 11 , it will not substantially affect the circulation of the coolant among the second confluence cavity 31 , the main cavity 11 and the first confluence cavity 21 in sequence.

[0034] In addition, the embodiment of the present application cools and dissipates heat of the electric heating element 50 by arranging a heat dissipation shell 40 and a second manifold 30 to form a heat dissipation cavity 41 that is fluidically connected to the second manifold cavity 31. This allows the conventional electric heating element 50 to be used to simulate the fuel elements of a nuclear reactor without changing the overall structure of the core.

[0035] In some embodiments, the electric heating element 50 includes a heating section 51, a heat dissipation section 52 connected to the heating section 51, an extension section 53 connected to the heat dissipation section 52, and a wire 54 connected to the extension section 53; wherein, the heating section 51 is used to generate heat to simulate a fuel element, and the heat dissipation section 52 and the extension section 53 basically do not generate heat; the heating section 51 is located in the main body cavity 11 and the second confluence cavity 31; the heat dissipation section 52 is located in the heat dissipation cavity 41; the extension section 53 extends to the outside of the heat dissipation shell 40.

[0036] In the embodiment of the present application, a heat-generating heating section 51 is located within the body cavity 11 and the second confluence cavity 31, thereby heating the coolant therein to simulate the heating of core fuel elements. Simultaneously, a heat-generating heat-dissipating section 52 and an extension section 53, which generate substantially no heat, are located within the heat-dissipating cavity 41 and outside the heat-dissipating housing 40, respectively. This helps lower the temperatures of the heat-dissipating cavity 41 and the outside of the heat-dissipating housing 40, thereby preventing the wires 54 and wire sealing material located outside the heat-dissipating housing 40 from malfunctioning due to excessive temperatures outside the heat-dissipating housing 40.

[0037] It's easy to understand that the electric heating element 50 in the embodiment of the present application can include an electric heating wire and a heating tube housing disposed externally thereto. For the heating section 51, the electric heating wire within its corresponding heating tube housing has a high winding density and high heating power per unit area, thereby generating a large amount of heat. For the heat dissipation section 52 and the extension section 53, the electric heating wire within their corresponding heating tube housings does not require winding for wiring, resulting in low heating power per unit area and negligible heat generation.

[0038] In some embodiments, the axial length of the heat dissipation shell 40 along the container body 10 is determined according to the temperature of the coolant in the second confluence cavity 31, the size of the second confluence cavity 31, the thermal conductivity of the coolant, the thermal conductivity of the heat dissipation shell 40, the temperature of the external environment, and the limited temperature of the wire 54.

[0039] As previously mentioned, in order to improve the accuracy of core thermal-hydraulic characteristics, related art requires the use of a core simulator with the same dimensions as the actual core to conduct core thermal-hydraulic characteristic studies. The inventors of this application have discovered that, in some cases, the gap between two adjacent electric heaters is only 1 mm, making it difficult to weld the heater housing to the bottom wall of the core simulator 1.

[0040] To address this technical issue, in some embodiments, the diameter of the extension section 53 is smaller than the diameters of the heat dissipation section 52 and the heating section 51. The core simulation device 1 further includes: a plurality of pipes 60, each of which is disposed radially outside a corresponding extension section 53 and welded to the heat dissipation shell 40; and each extension section 53 is welded to a corresponding pipe 60. The embodiments of the present application, by providing the pipes 60, can improve the strength of the extension section 53 and reinforce the extension section 53.

[0041] Since the extension section 53 basically generates no heat, it is convenient to set the diameter of the extension section 53 to be smaller than the diameters of the heat dissipation section 52 and the heating section 51. In this way, it can ensure that the heating section 51 in the main body cavity 11, the first confluence cavity 21, and the second confluence cavity 31 are the same size as the fuel element, thereby ensuring the reliability of the test effect. At the same time, when the gap between two adjacent electric heating elements is only 1 mm, sufficient space can be provided for welding the pipe 60 and the heat dissipation shell 40, thereby reducing the difficulty of installing the electric heating element 50 in the core simulation device 1.

[0042] In some embodiments, the heat dissipation shell 40 includes a heat dissipation cover 42 and a heat dissipation cylinder 43 for connecting the heat dissipation cover 42 to the second bus 30. The heat dissipation cylinder 43, the second bus 30 and the heat dissipation cover 42 together form a heat dissipation cavity 41. The heat dissipation cover 42 and the heat dissipation cylinder 43 are both configured to dissipate heat to the outside. The heat dissipation cover 42 forms a plurality of heat dissipation holes for each electric heating element 50 to pass through; the pipe 60 is welded to the periphery of the heat dissipation hole on the side away from the second bus 30; and the extension section 53 is welded to the pipe 60 on the side away from the heat dissipation cover 42. The embodiment of the present application is conducive to the heat dissipation of the heat in the heat dissipation cavity 41 through the heat dissipation cover 42 and the heat dissipation cylinder 43, thereby reducing the temperature of the heat dissipation section 52 by configuring both the heat dissipation cover 42 and the heat dissipation cylinder 43 to dissipate heat to the outside.

[0043] It is easy to understand that in order to ensure the heat dissipation effect of the heat dissipation cover plate 42 and the heat dissipation cylinder 43, the inner and outer surfaces of the heat dissipation cover plate 42 and the heat dissipation cylinder 43 are not provided with heat insulation materials or thermal insulation materials that can affect heat dissipation.

[0044] In some embodiments, the diameter of the heat dissipation through-hole is smaller than the diameter of the heat dissipation section 52 and larger than the diameter of the extension section 53. The extension section 53 extends from a corresponding heat dissipation through-hole to the outside of the heat dissipation housing 40. In the embodiment of the present application, the diameter of the heat dissipation through-hole is set to be smaller than the diameter of the heat dissipation section 52 and larger than the diameter of the extension section 53. When assembling the electric heater 50, the peripheral wall of the heat dissipation through-hole can be used to limit the downward movement of the heat dissipation section 52, preventing the unsoldered electric heater 50 from falling through the heat dissipation through-hole.

[0045] In some embodiments, the bottom wall of the heat dissipation segment 52 located radially outside the extension segment 53 contacts the peripheral wall of the heat dissipation through hole, so that the heat dissipation segment 52 is supported by the peripheral wall of the heat dissipation through hole.

[0046] In some embodiments, the first convergence member 20 includes a first convergence plate 22 and a first end plate 23 arranged opposite to each other, and a first convergence tube member 24 connecting the first convergence plate 22 and the first end plate 23. The first convergence plate 22, the first end plate 23 and the first convergence tube member 24 together form a first convergence cavity 21; the first convergence plate 22 is connected to the container body 10, and the first convergence plate 22 is formed with a plurality of first convergence mounting holes for the electric heating element 50 to pass through and a plurality of first convergence holes for the coolant to circulate; wherein, the electric heating element 50 enters the first convergence mounting hole facing one end of the first end plate 23, and is limited by the first convergence mounting hole.

[0047] In an embodiment of the present application, the first manifold plate 22 defines a plurality of first manifold mounting holes for passage of the electric heating element 50, thereby limiting the position of the electric heating element 50 through the plurality of first manifold mounting holes. Because the first manifold plate 22 also defines a plurality of first manifold holes for passage of coolant, coolant can enter the first manifold cavity 21 from the main body cavity 11, simulating the flow of coolant in the core. In such an embodiment, the core simulated by the core simulation device is the core of a grid-type liquid metal-cooled nuclear reactor.

[0048] In some embodiments, the positions of the multiple first bus mounting holes formed by the first bus plate 22 are set to be aligned with the multiple heat dissipation holes formed by the heat dissipation cover plate 42 respectively, so as to avoid bending and deformation of the electric heating element 50, thereby preventing damage and failure of the electric heating element 50, which would affect the accuracy of the core simulation device 1 in conducting core thermal-hydraulic research.

[0049] In some embodiments, the second busbar 30 includes a second busbar 32 and a second end plate 33 arranged opposite to each other, and a second busbar tube 34 connecting the second busbar 32 and the second end plate 33. The second busbar 32, the second end plate 33 and the second busbar tube 34 together form a second busbar cavity 31; the second busbar 32 is connected to the container body 10, and the first busbar 22, the container body 10 and the second busbar 32 together form a body cavity 11; the second busbar 32 is formed with a plurality of second busbar mounting holes for the passage of the electric heating element 50 and a plurality of second busbar holes for the circulation of the coolant; the second end plate 33 is formed with a plurality of second end plate 33 holes for the passage of the electric heating element 50; the electric heating element 50 passes through the second busbar mounting holes and the second end plate 33 holes in turn to enter the heat dissipation cavity 41.

[0050] In the embodiment of the present application, the second manifold 32 forms a plurality of second manifold mounting holes for the passage of the electric heating elements 50, and the second end plate 33 forms a plurality of second end plate holes for the passage of the electric heating elements 50. The second manifold mounting holes cooperate with the second end plate holes to achieve precise positioning of the plurality of electric heating elements 50 within the second manifold cavity 31. Furthermore, the second manifold 32 also forms a plurality of second manifold holes for the circulation of coolant, thereby allowing coolant to enter the main body cavity 11 from the second manifold cavity 31, simulating the flow of coolant in the core.

[0051] In some embodiments, an insulation layer is provided on the outer wall of the first end plate 23, the outer wall of the first collecting tube member 24, the outer wall of the second collecting tube member 34, the outer wall of the container body 10, the outer wall of the first collecting plate 22 located radially outside the container body 10, and the outer wall of the second collecting plate 32 located radially outside the container body 10, thereby preventing the first collecting cavity 21, the second collecting cavity 31, and the main body cavity 11 from exchanging heat with the outside, so that the temperature inside the first collecting cavity 21, the second collecting cavity 31, and the main body cavity 11 remains stable.

[0052] In some embodiments, the core simulation device 1 further includes: a first coolant interface 70 and a second coolant interface 80. The first coolant interface 70 and the second coolant interface 80 are respectively in fluid communication with the first confluence cavity 21 and the second confluence cavity 31. The coolant can enter the second confluence cavity 31 through the second coolant interface 80, and then enter the main body cavity 11 in turn to exchange heat with the multiple electric heating elements 50, and then enter the first confluence cavity 21, and then flow out from the first coolant interface 70, so that the coolant can flow in the first confluence cavity 21, the second confluence cavity 31 and the main body cavity 11, simulating the flow of coolant in the core.

[0053] An embodiment of the present application also provides a method for preparing a core simulation device 1 , which is used to prepare the core simulation device 1 provided in any embodiment of the present application.

[0054] Figure 2 FIG. 1 is a flow chart of a method for preparing a core simulation device 1 according to an embodiment of the present application. Figure 2As shown, the preparation method of an embodiment of the present application includes: S1, determining the diameter of the extension section 53 of the electric heating element 50, the wall thickness of the tube 60, the gap between the extension section 53 and the tube 60, and the size of the heat dissipation hole of the heat dissipation shell 40 according to the minimum spacing between adjacent electric heating elements 50 in the container body 10 and the welding space requirements between the tube 60 and the heat dissipation shell 40; S2, determining the axial length of the heat dissipation shell 40 along the container body 10 according to the temperature of the coolant in the second confluence cavity 31, the size of the second confluence cavity 31, the thermal conductivity of the coolant, the thermal conductivity of the heat dissipation shell 40, and the temperature of the external environment; S3, assembling and welding the electric heating element 50, the first confluence 20, the container body 10, the second confluence 30, the heat dissipation shell 40 and the tube 60 together.

[0055] The embodiment of the present application determines the diameter of the extension section 53 of the electric heating element 50, the wall thickness of the tube 60, the gap between the extension section 53 and the tube 60, and the size of the heat dissipation hole of the heat dissipation shell 40 based on the minimum spacing between adjacent electric heating elements 50 in the container body 10 and the welding space requirements between the tube 60 and the heat dissipation shell 40. This can ensure that the heating section 51 in the main body cavity 11, the first confluence cavity 21, and the second confluence cavity 31 are the same size as the fuel element, thereby ensuring the reliability of the test effect. In addition, when the gap between two adjacent electric heating elements is only 1 mm, sufficient space can be provided for welding the tube 60 and the heat dissipation shell 40, thereby reducing the difficulty of installing the electric heating element 50 in the core simulation device 1.

[0056] Furthermore, the axial length of the heat dissipation shell 40 along the container body 10 is determined according to the temperature of the coolant in the second confluence cavity 31, the size of the second confluence cavity 31, the thermal conductivity of the coolant, the thermal conductivity of the heat dissipation shell 40, and the temperature of the external environment, so that the heat dissipation shell 40 can meet the requirement that the wire 54 and the wire sealing material arranged outside the heat dissipation shell 40 do not exceed the specified temperature, thereby avoiding the problem of failure of the wire 54 due to excessive temperature, and thus ensuring that the prepared core simulation device 1 can work stably.

[0057] In some embodiments, step S1 includes: S11, determining the minimum spacing between the outer surfaces of adjacent tubes 60 based on the welding space requirements between the tubes 60 and the heat dissipation shell 40; S12, determining the diameter of the extension section 53 of the electric heating element 50, the wall thickness of the tube 60, the gap between the extension section 53 and the tube 60, and the size of the heat dissipation hole of the heat dissipation shell 40 based on the minimum spacing between adjacent electric heating elements 50 in the container body 10 and the minimum spacing determined in step S11.

[0058] In some embodiments, the minimum spacing between adjacent tubes 60 can be in the range of 1-2 mm, and the wall thickness of the tube 60 can be in the range of 0.5-1 mm, so as to provide sufficient space for welding the tube 60 to the heat dissipation shell 40, while ensuring that the tube 60 can meet the requirements of improving the strength of the extension section 53 and reinforcing the extension section 53.

[0059] It is easy to understand that the coolant in the heat dissipation cavity 41 basically does not flow, and the heat brought by the high-temperature coolant in the second confluence cavity 31 is transferred purely by heat conduction. The outward heat dissipation power of the heat dissipation shell 40 can be calculated based on the size of the second confluence cavity 31 and the heat dissipation conditions of the heat dissipation shell 40 in the environment. In this way, the temperature of the coolant gradually decreases from top to bottom along the axial direction of the heat dissipation shell 40.

[0060] In some embodiments, step S2 includes: S21, determining the outward heat dissipation power of the heat dissipation shell 40 according to the temperature of the coolant in the second confluence cavity 31, the size of the second confluence cavity 31, the thermal conductivity of the heat dissipation shell 40 and the temperature of the external environment; S22, determining the temperature distribution of the coolant in the heat dissipation cavity 41 along the length direction of the heat dissipation cavity 41 according to the heat dissipation power in step S21; S23, determining the axial length of the heat dissipation shell 40 along the container body 10 according to the limited temperature of the wire 54 and the temperature distribution of the coolant in the heat dissipation cavity 41 along the length direction of the heat dissipation cavity 41.

[0061] In some embodiments, a three-dimensional model of the core simulation device 1 can be established, and the heat exchange calculation of the heat dissipation shell 40 can be performed using the finite element analysis method (commercial software CFD, etc.) to obtain the temperature of the heat dissipation shell 40 away from the second confluence cavity 31.

[0062] In some embodiments, the limited temperature of the wire 54 and the wire sealing material can be set to be lower than the upper temperature limit of the normal operation of the wire 54, thereby ensuring that the electric heating element 50 can operate normally and stably in the core simulation device 1.

[0063] In some embodiments, step S3 includes: S31, welding the first bus 20 and the second bus 30 to the two ends of the container body 10 respectively; welding each tube 60 to the heat dissipation shell 40; S32, inserting the electric heating element 50 into the container body 10 from the side of the second bus 30 and into the first bus 20, inserting the heat dissipation section 52 and the extension section 53 of the electric heating element 50 into the heat dissipation shell 40 and the corresponding tube 60, and welding the heat dissipation shell 40 to the second bus 30; S33, welding the extension section 53 of the electric heating element 50 to the corresponding tube 60.

[0064] The embodiment of the present application facilitates the welding operation of the core simulation device 1 through the above-mentioned steps S31 to S33, which is conducive to reducing the difficulty of installing the core simulation device 1. Specifically, compared with directly welding the electric heating element 50 to the heat dissipation shell 40, the embodiment of the present application welds the heat dissipation shell 40 with an additional pipe 60, and then inserts the electric heating element 50 into the pipe 60 and welds it to the pipe 60, which is conducive to avoiding damage to the electric heating element 50 during welding in a small space. Moreover, during the process of welding the pipe 60, if a pipe 60 is damaged, it can be directly replaced, which is more conducive to ensuring the welding effect.

[0065] In some embodiments, the length of the pipe 60 is substantially the same as the extension section 53 of the electric heater 50 , thereby reducing the difficulty of welding the extension section 53 and the pipe 60 and preventing damage to the electric heater 50 .

[0066] The following describes in detail the process of preparing the core simulation device 1 using the method of the present application, taking the cylindrical container body 10 and the rod-shaped electric heating element 50 as an example.

[0067] The minimum spacing between adjacent electric heaters 50 within the vessel body 10 is determined based on the minimum spacing between fuel elements within the core. Based on the required welding space between the tubes 60 and the heat dissipation shell 40, the minimum spacing between adjacent tubes 60 is set to 1-2 mm, and the wall thickness of the tubes 60 is set to 0.5-1 mm. The diameter of the extension section 53 of the electric heater 50, the gap between the extension section 53 and the tube 60, and the size of the heat dissipation holes in the heat dissipation shell 40 are also determined.

[0068] The limit temperature of the wire 54 is determined based on the upper limit of the normal operating temperature of the wire 54 of the electric heater 50. The outward heat dissipation power of the heat dissipation housing 40 is determined based on the temperature of the coolant in the second confluence cavity 31, the size of the second confluence cavity 31, the thermal conductivity of the heat dissipation housing 40, and the temperature of the external environment. Based on the outward heat dissipation power of the heat dissipation housing 40, the temperature distribution of the coolant in the heat dissipation cavity 41 along the length of the heat dissipation cavity 41 is determined. Based on the temperature distribution of the coolant in the heat dissipation cavity 41 along the length of the heat dissipation cavity 41, the axial length of the heat dissipation housing 40 along the container body 10 is determined.

[0069] Weld the first busbar 20 and the second busbar 30 to the two ends of the container body 10 respectively, and weld each pipe 60 to the heat dissipation shell 40; insert the electric heating element 50 into the container body 10 from one side of the second busbar 30 and extend it out of the first busbar 22, insert the heat dissipation section 52 and the extension section 53 of the electric heating element 50 into the heat dissipation shell 40 and the corresponding pipe 60; weld the heat dissipation shell 40 to the second busbar 30; weld the extension section 53 of the electric heating element 50 to the corresponding pipe 60, and complete the preparation of the core simulation device 1.

[0070] Regarding the embodiments of the present application, it should also be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other to obtain new embodiments.

[0071] The above description is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A core simulation device for simulating a reactor core, characterized in that: The core simulation device comprises: A container body, used to simulate a core container, with both axial ends of the container body being open; A first manifold and a second manifold are respectively connected to the axial ends of the container body to close the openings at the two ends and form a body cavity together with the container body, wherein the first manifold and the second manifold further form a first manifold cavity and a second manifold cavity respectively in fluid communication with the body cavity for coolant flow; a heat dissipation shell, which together with the second confluence piece forms a heat dissipation cavity in fluid communication with the second confluence cavity; A plurality of electric heating elements, used to simulate the heating of a plurality of fuel elements of a core, each of the electric heating elements extending from the body cavity through the second confluence cavity and the heat dissipation cavity to the outside of the heat dissipation shell; The heat dissipation shell is configured to dissipate heat to the outside to cool the portion of the electric heating element located in the heat dissipation cavity, thereby reducing the temperature of the portion of the electric heating element located outside the heat dissipation shell to below a limited temperature.

2. The core simulation device according to claim 1, characterized in that: The electric heating element includes a heating section, a heat dissipation section connected to the heating section, an extension section connected to the heat dissipation section, and a wire connected to the extension section; wherein the heating section is used to generate heat to simulate the fuel element, and the heat dissipation section and the extension section substantially do not generate heat; The heating section is located in the body cavity and the second confluence cavity; The heat dissipation section is located in the heat dissipation cavity; The extension section extends to the outside of the heat dissipation shell.

3. The core simulation device according to claim 2, characterized in that: The diameter of the extension section is smaller than the diameters of the heat dissipation section and the heating section; The core simulation device further comprises: a plurality of pipes, each of which is sleeved on the radially outer side of a corresponding one of the extension sections and welded to the heat dissipation shell; Each of the extension sections is welded to a corresponding one of the pipes.

4. The core simulation device according to claim 3, characterized in that: The heat dissipation shell comprises a heat dissipation cover plate and a heat dissipation cylinder for connecting the heat dissipation cover plate with the second busbar, wherein the heat dissipation cylinder, the second busbar and the heat dissipation cover plate together form the heat dissipation cavity; The heat dissipation cover plate and the heat dissipation cylinder are both configured to dissipate heat to the outside; The heat dissipation cover plate is formed with a plurality of heat dissipation through holes for each of the electric heating elements to pass through; The tube is welded to the periphery of the heat dissipation through hole at a side away from the second current collector; The extension section is welded to the pipe fitting at a side away from the heat dissipation cover plate.

5. The core simulation device according to claim 4, characterized in that: The diameter of the heat dissipation through hole is smaller than the diameter of the heat dissipation section and larger than the diameter of the extension section; The extending section extends from a corresponding one of the heat dissipation through holes to the outside of the heat dissipation shell.

6. The core simulation device according to claim 1, characterized in that: The first busbar comprises a first busbar plate and a first end plate which are oppositely arranged, and a first busbar cylinder connecting the first busbar plate and the first end plate, wherein the first busbar plate, the first end plate and the first busbar cylinder together form the first busbar cavity; The first manifold is connected to the container body, and is formed with a plurality of first manifold mounting holes for the electric heating element to pass through and a plurality of first manifold holes for the coolant to flow through; Wherein, one end of the electric heating element facing the first end plate enters the first conduit installation hole.

7. The core simulation device according to claim 6, characterized in that: The second busbar comprises a second busbar plate and a second end plate which are arranged opposite to each other, and a second busbar barrel connecting the second busbar plate and the second end plate, wherein the second busbar plate, the second end plate and the second busbar barrel together form the second busbar cavity; The second manifold is connected to the container body, and the first manifold, the container body, and the second manifold together form the body cavity; The second manifold is formed with a plurality of second manifold mounting holes for the electric heating element to pass through and a plurality of second manifold holes for the coolant to flow through; The second end plate is formed with a plurality of second end plate holes for the electric heating element to pass through; The electric heating element passes through the second confluence installation hole and the second end plate hole in sequence and enters the heat dissipation cavity.

8. The core simulation device according to claim 7, characterized in that: An insulation layer is provided on the outer wall of the first end plate, the outer wall of the first collecting tube member, the outer wall of the second collecting tube member, the outer wall of the container body, the outer wall of the first collecting plate located radially outside the container body, and the outer wall of the second collecting plate located radially outside the container body.

9. The core simulation device according to any one of claims 1 to 8, characterized in that: Also includes: The first coolant interface and the second coolant interface are fluidly connected to the first confluence chamber and the second confluence chamber respectively. The coolant can enter the second confluence chamber through the second coolant interface, and enter the main body cavity in turn to exchange heat with the multiple electric heating elements, then enter the first confluence chamber, and then flow out from the first coolant interface.

10. A method for preparing a core simulation device, for preparing the core simulation device according to any one of claims 1 to 9, characterized in that: The preparation method comprises: S1. Determine the diameter of the extension section of the electric heater, the wall thickness of the tube, the gap between the extension section and the tube, and the size of the heat dissipation hole of the heat dissipation shell based on the minimum spacing between adjacent electric heaters in the container body and the welding space requirements between the tube and the heat dissipation shell; S2. Determine the length of the heat dissipation shell along the axial direction of the container body according to the temperature of the coolant in the second confluence cavity, the size of the second confluence cavity, the thermal conductivity of the coolant, the thermal conductivity of the heat dissipation shell, and the temperature of the external environment; S3. Assemble and weld the electric heating element, the first busbar, the container body, the second busbar, the heat dissipation shell, and the pipe together.

11. The preparation method according to claim 10, characterized in that: The S3 steps include: S31, welding the first busbar and the second busbar to both ends of the container body respectively; welding the plurality of pipes to the heat dissipation shell; S32, inserting the electric heater into the container body from one side of the second busbar and into the first busbar, inserting the heat dissipation section and extension section of the electric heater into the heat dissipation shell and corresponding pipe fittings, and welding the heat dissipation shell to the second busbar; S33, welding the extension section of the electric heating element to the corresponding pipe fitting.

Images