A fluid flow path equivalent method for nuclear reactor assembly seismic testing

Abstract

The embodiment of the present application relates to a kind of fluid flow channel equivalent method for the vibration resistance test of nuclear reactor assembly.It includes: obtaining the target test condition of test object, wherein the target test condition is determined according to the object characteristics corresponding to test object;Target test structure is selected for the vibration resistance test of test object using target test condition, and the mechanism parameter corresponding to target test structure is set;Fluid inertia effect simulation test is carried out on test object using target test structure, and the mechanical parameter of test object in fluid inertia effect simulation test is obtained.The fluid flow channel equivalent method for the vibration resistance test of nuclear reactor assembly provided in the application embodiment can select test condition in advance by the characteristics of test object, and select corresponding test structure and parameter by test condition, so as to obtain accurate mechanical parameter in the aspect of vibration resistance performance of nuclear reactor assembly by equivalent method without designing test environment according to real environment completely.

Description

Technical Field

[0001] This invention relates to the field of vibration resistance measurement technology for nuclear reactor components, and more particularly to an equivalent fluid flow channel method for vibration resistance testing of nuclear reactor components. Background Technology

[0002] In a lead-bismuth fast neutron nuclear reactor, multiple components (including fuel rod assemblies, shielding assemblies, control rod assemblies, etc.) are arranged closely on a grid and immersed in a liquid lead-bismuth environment (cooling medium). During operation, the components emit a large amount of nuclear energy (neutrons) due to nuclear reactions, heating the surrounding cooling medium. The cooling medium circulates under the drive of a circulation pump, thus gaining thermal energy.

[0003] The vibrations generated during the operation of the circulating pumps are transmitted to the reactor assemblies. To ensure the safety of the nuclear reactor during long-term operation, vibration resistance tests must be conducted on various assemblies beforehand. The test environment for vibration resistance tests needs to be as close as possible to the physical environment inside the actual nuclear reactor core, but designing the test environment exactly according to the real environment would be extremely costly. For example, to meet the requirements of realism, lead bismuth is used as the medium for testing, which requires the establishment of auxiliary supporting equipment such as thermal control, circulation, cooling, and cleaning systems. Moreover, lead bismuth has certain corrosive and toxic properties. These challenges pose a significant hurdle to the design of vibration resistance tests for these reactor core assemblies. Summary of the Invention

[0004] To solve the above-mentioned technical problems, or at least partially solve them, this application provides an equivalent method for fluid flow channels in vibration resistance testing of nuclear reactor components.

[0005] In a first aspect, an equivalent method for fluid flow channels in vibration resistance testing of nuclear reactor components is provided, including:

[0006] Obtain the target test conditions for the test object, wherein the target test conditions are determined based on the object characteristics corresponding to the test object;

[0007] Using the target test conditions, a target test structure is selected for conducting vibration resistance tests on the test object, and the mechanism parameters corresponding to the target test structure are set.

[0008] The test object is subjected to a fluid inertial effect simulation test using the target test structure to obtain the mechanical parameters of the test object in the fluid inertial effect simulation test.

[0009] In an optional embodiment of this application, obtaining the target experimental conditions for the experimental subject includes:

[0010] Obtain the object features of the test object, wherein the object features include geometric dimensions and technical parameters;

[0011] Obtain a first limiting condition set using the geometric dimensions, and obtain a second limiting condition set using the technical parameters;

[0012] The first limiting condition and the second limiting condition are determined as the target test conditions.

[0013] In an optional embodiment of this application, the target test structure includes a hexagonal tube structure.

[0014] In an optional embodiment of this application, the test object is subjected to a fluid inertial effect simulation test using the target test structure to obtain the mechanical parameters of the test object in the fluid inertial effect simulation test, including:

[0015] The components and tooling of the hexagonal tube are simulated using shell elements, and the fluid in the hexagonal tube is simulated using solid elements.

[0016] By connecting the fluid to the outer wall of the component and the fluid to the outer wall of the tooling, a simulated test environment is obtained;

[0017] Under the simulated test environment, the mechanical parameters that affect the vibration resistance of the component are measured.

[0018] In an optional embodiment of this application, after docking the fluid with the outer wall of the component and the fluid with the outer wall of the tooling, the method further includes:

[0019] The displacements of shell elements and solid elements are constrained using a coupled degree of freedom algorithm.

[0020] In an optional embodiment of this application, the measurement of the mechanical parameters that affect the vibration resistance of the component includes:

[0021] Obtain the fluid type and channel spacing corresponding to the fluid;

[0022] The first and second frequencies of the target test structure are calculated using the Lanczos method based on the fluid type and the channel spacing, and the first and second frequencies are determined as the mechanical parameters.

[0023] The fluid flow channel equivalent method for vibration resistance testing of nuclear reactor components provided in this application can pre-select test conditions based on the characteristics of the test object, and select corresponding test structures and parameters based on the test conditions. In this way, accurate mechanical parameters of the vibration resistance performance of nuclear reactor components can be obtained through the equivalent method without having to design the test environment exactly according to the real environment. Attached Figure Description

[0024] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0026] Figure 1 A flowchart illustrating an equivalent method for a fluid flow channel in a vibration resistance test of a nuclear reactor assembly, provided as an embodiment of this application;

[0027] Figure 2 This application provides a method for simulating the fluid inertial effect on a test object. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will be combined with the present invention.

[0029] The accompanying drawings of the embodiments of the invention provide a clear and complete description of the technical methods in the embodiments of the invention. Obviously, the described embodiments are only some embodiments of the invention, and not all embodiments. Based on the embodiments of the invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the invention.

[0030] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0031] Figure 1 An equivalent method for a fluid flow channel in a vibration resistance test of a nuclear reactor assembly, as provided in this application embodiment, is as follows: Figure 1 As shown, the method includes:

[0032] Step S11: Obtain the target test conditions for the test object, wherein the target test conditions are determined based on the object characteristics corresponding to the test object.

[0033] In an optional embodiment of this application, obtaining the target test conditions for the test subject includes:

[0034] The object characteristics of the test object are obtained, including geometric dimensions and technical parameters. A first limiting condition set using the geometric dimensions is obtained, and a second limiting condition set using the technical parameters is obtained. The first limiting condition and the second limiting condition are determined as the target test conditions.

[0035] It should be noted that a low-density liquid was used instead of the lead-bismuth solution to achieve certain kinetic equivalence relationships. To simulate the influence of the liquid coolant on the vibration conditions of the components, a gallium-indium-tin alloy was used instead of the lead-bismuth alloy molten liquid in the test bench. The actual environmental comparison of the simulated test environment is shown in Table 1. In the actual lead-bismuth environment, the channel gap is approximately 2 mm. In the experiment, a gallium-indium-tin alloy liquid metal was used, and by changing the narrow channel gap to 1.2 mm, it was able to simulate the dynamic characteristics of the lead-bismuth molten liquid (see Table 2 for simulation results).

[0036]

[0037] Table 1. Comparison of fluid media in actual and simulated test environments.

[0038] Step S12: Select the target test structure for conducting vibration resistance tests on the test object using the target test conditions, and set the corresponding mechanism parameters of the target test structure.

[0039] In this embodiment, a suitable test device structure is selected based on the geometric dimensions and technical parameters of the test object. The bench assembly simulation method conforms to the actual structure and test requirements. The bench is waterproof. Necessary sensors are installed to measure key mechanical quantities such as strain and impact force during vibration. In a real environment, the channel spacing is 2 mm, and a gallium indium tin alloy is used as an equivalent liquid. The tooling is adjusted to achieve a channel spacing of 1.2 mm. After the test, the sealing performance of the component simulation is checked using a helium detector as required.

[0040] Step S13: Use the target test structure to conduct a fluid inertial effect simulation test on the test object to obtain the mechanical parameters of the test object in the fluid inertial effect simulation test.

[0041] In this embodiment of the application, the target test structure includes a hexagonal tube structure.

[0042] In this embodiment of the application, a fluid inertial effect simulation test is conducted on the test object using the target test structure to obtain the mechanical parameters of the test object in the fluid inertial effect simulation test, including:

[0043] refer to Figure 2As shown, the components and tooling of the hexagonal tube are simulated using shell elements, and the fluid in the hexagonal tube is simulated using solid elements. The fluid is connected to the outer wall of the component and the outer wall of the tooling to obtain the simulated test environment. Under the simulated test environment, the mechanical parameters that affect the vibration resistance of the component are measured.

[0044] In this embodiment of the application, after docking the fluid with the outer wall of the component and the fluid with the outer wall of the tooling, the method further includes: constraining the displacement of the shell unit and the solid unit using a coupled degree of freedom algorithm.

[0045] In this embodiment of the application, measuring the mechanical parameters that affect the vibration resistance of the component by the fluid includes: obtaining the fluid type and channel spacing corresponding to the fluid; using the Lanczos method to calculate the first-order frequency and second-order frequency corresponding to the target test structure based on the fluid type and channel spacing, and determining the first-order frequency and second-order frequency as the mechanical parameters.

[0046]

[0047] Table 2. Simulation results of equivalent flow channel

[0048] The fluid flow channel equivalent method for vibration resistance testing of nuclear reactor components provided in this application can pre-select test conditions based on the characteristics of the test object, and select corresponding test structures and parameters based on the test conditions. In this way, accurate mechanical parameters of the vibration resistance performance of nuclear reactor components can be obtained through the equivalent method without having to design the test environment exactly according to the real environment.

[0049] The specific embodiments of the invention have been described in detail above. However, as examples, the invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications or substitutions to the invention are also within the scope of the invention. Therefore, all equivalent transformations, modifications, and improvements made without departing from the spirit and principles of the invention should be covered within the scope of the invention.

Claims

1. An equivalent method for fluid flow channels in vibration resistance testing of nuclear reactor assemblies, characterized in that, include: Obtain the target test conditions for the test object, wherein the target test conditions are determined based on the object characteristics corresponding to the test object; Using the target test conditions, a target test structure is selected for conducting vibration resistance tests on the test object, and the mechanism parameters corresponding to the target test structure are set. The test object is subjected to a fluid inertial effect simulation test using the target test structure to obtain the mechanical parameters of the test object in the fluid inertial effect simulation test; The target experimental conditions for obtaining the experimental subjects include: Obtain the object features of the test object, wherein the object features include geometric dimensions and technical parameters; Obtain a first limiting condition set using the geometric dimensions, and obtain a second limiting condition set using the technical parameters; The first limiting condition and the second limiting condition are determined as the target experimental conditions; To simulate the impact of liquid coolant on the vibration conditions of the components, gallium indium tin alloy was used instead of lead-bismuth alloy molten metal to fill the test bench. In the actual lead-bismuth environment, the channel gap is 2 mm. In the test, gallium indium tin alloy liquid metal was used. By changing the narrow channel gap to 1.2 mm, it was possible to simulate the dynamic characteristics of lead-bismuth molten metal. The corresponding geometric dimensions and technical parameters include fluid medium density, viscosity, and channel gap. Thus, the vibration resistance performance of nuclear reactor components can be obtained through an equivalent method without having to design the test environment exactly according to the real environment.

2. The method according to claim 1, characterized in that, The target test structure includes a hexagonal tube structure.

3. The method according to claim 2, characterized in that, The test object is subjected to a fluid inertial effect simulation test using the target test structure to obtain the mechanical parameters of the test object in the fluid inertial effect simulation test, including: The components and tooling of the hexagonal tube are simulated using shell elements, and the fluid in the hexagonal tube is simulated using solid elements. By connecting the fluid to the outer wall of the component and the fluid to the outer wall of the tooling, a simulated test environment is obtained; Under the simulated test environment, the mechanical parameters that affect the vibration resistance of the component are measured.

4. The method according to claim 3, characterized in that, After docking the fluid with the outer wall of the component and the fluid with the outer wall of the tooling, the method further includes: The displacements of shell elements and solid elements are constrained using a coupled degree of freedom algorithm.

5. The method according to claim 4, characterized in that, The mechanical parameters that affect the vibration resistance of the component by measuring the fluid include: Obtain the fluid type and channel spacing corresponding to the fluid; The first and second frequencies of the target test structure are calculated using the Lanczos method based on the fluid type and the channel spacing, and the first and second frequencies are determined as the mechanical parameters.

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