Method for preparing water film on surface of nuclear fuel rod and device for determining parameters for preparing water film

Abstract

The invention discloses a method for preparing a water film on the surface of a nuclear fuel rod and a device for determining parameters for preparing the water film, and belongs to the technical field of nuclear engineering. The method for preparing the surface antifriction water film comprises the following steps that water is sprayed to the surface of the zirconium alloy cladding pipe to form a lubricating water layer, the lubricating water layer or a water source of the lubricating water layer is magnetized through a magnetic field, the water of the lubricating water layer is more evenly distributed on the surface of the zirconium alloy cladding pipe, and the antifriction water film is formed. The water film is magnetized by introducing a magnetic field, so that the wettability of the water film is changed, and the lubricating performance of the water film is improved.

Description

Technical Field

[0001] The invention relates to the field of nuclear engineering technology, in particular to the field of nuclear fuel rod installation technology, specifically, to a method for preparing a water film on the surface of a nuclear fuel rod and a device for determining parameters for preparing the water film. Background Art

[0002] Nuclear power is a technology that uses nuclear physics reactions to generate energy for power generation. As an economical, reliable and clean energy, it has become the main source of electricity for some countries. The core component of a nuclear power plant that realizes nuclear energy-thermal energy conversion is the nuclear reactor, and the nuclear fuel assembly is the core component of the nuclear reactor core.

[0003] Each fuel assembly contains multiple fuel rods and positioning grids. To ensure installation accuracy, the rod pulling system is often used to assemble the fuel assembly during installation. However, during the rod pulling process, the fuel rods are clamped by the rigid convex and springs, causing relative slip between the surface of the fuel rods and the rigid convex and springs. At this time, the contact interface of the fuel rods will produce large shear stress, resulting in severe friction and wear on the surface of the fuel rods. Such wear will cause the chromium coating on the surface of the fuel rods to fail, thus affecting the safety and reliability of the nuclear fuel assembly.

[0004] In order to reduce the influence of wear during the rod drawing process, a water lubrication device is usually added between the pre-packing platform and the assembly platform. However, the water film droplets prepared on the surface of the zirconium alloy cladding tube by conventional water lubrication are large and have poor lubrication performance. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a method for preparing a water film on the surface of a nuclear fuel rod and a device for determining the parameters for preparing the water film. The present invention magnetizes water by introducing a magnetic field, thereby changing the wettability of the water film and thereby increasing the lubrication performance of the water film.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] A method for preparing a water film on the surface of a nuclear fuel rod comprises: spraying water onto the surface of a zirconium alloy cladding tube to form a lubricating water layer and magnetizing the lubricating water layer or a water source of the lubricating water layer through a magnetic field, so that the water in the lubricating water layer is more evenly distributed on the surface of the zirconium alloy cladding tube to form a friction-reducing water film.

[0008] As a specific implementation of the present invention, the magnetic field is a steady-state magnetic field.

[0009] As a specific embodiment of the present invention, the magnetic field magnetizes the lubricating water layer, and during the magnetization process, the magnetic field moves along the axis of the zirconium alloy cladding tube, so that the water film is evenly distributed along the axial direction of the zirconium alloy cladding tube.

[0010] As a specific embodiment of the present invention, the magnetic field magnetizes the lubricating water layer, and during the magnetization process, the magnetic field rotates around the axis of the zirconium alloy cladding tube, so that the water film is evenly distributed along the circumference of the zirconium alloy cladding tube.

[0011] As a specific embodiment of the present invention, the magnetic field magnetizes the lubricating water layer, and during the magnetization process, the magnetic field rotates around the axis of the zirconium alloy cladding tube and moves along the axis of the zirconium alloy cladding tube.

[0012] As a specific implementation of the present invention, the magnetic field is fixed and the zirconium alloy cladding tube rotates around its axis.

[0013] As a specific embodiment of the present invention, the method further includes adjusting the humidity of the gas around the surface of the zirconium alloy cladding tube to reduce the evaporation rate of the friction-reducing water film on the surface of the zirconium alloy cladding tube.

[0014] A device for determining parameters for preparing a water film, comprising:

[0015] A traction mechanism, used for driving the zirconium alloy cladding tube to move along its axial direction;

[0016] The first speed measuring mechanism is used to measure the speed of driving the zirconium alloy cladding tube to move along its axial direction;

[0017] A force measuring mechanism, used to measure the traction force of the traction mechanism on the zirconium alloy cladding tube, thereby determining the friction force;

[0018] A spacer grid simulation mechanism for applying friction force to the peripheral side wall of the zirconium alloy cladding tube;

[0019] A water spraying mechanism, used for spraying water onto the surface of the zirconium alloy cladding tube to form a lubricating water layer;

[0020] The magnetic field mechanism is used to generate a magnetic field around the zirconium alloy cladding tube and magnetize the lubricating water layer or the water source of the lubricating water layer through the magnetic field, so that the water distribution of the lubricating water layer is more uniform, forming a friction-reducing water film.

[0021] As a specific embodiment of the present invention, the water spraying mechanism adopts an atomizing nozzle to spray water mist onto the surface of the zirconium alloy cladding tube, so that the lubricating water layer can be made more uniform.

[0022] As a specific embodiment of the present invention, the traction mechanism simultaneously drives the zirconium alloy cladding tube to rotate along its center line, and also includes a second speed measuring mechanism for measuring the rotation speed of the zirconium alloy cladding tube relative to the magnetic field.

[0023] As a specific embodiment of the present invention, it also includes a humidity adjustment mechanism for adjusting the humidity of the gas around the surface of the zirconium alloy cladding tube.

[0024] As a specific embodiment of the present invention, compared with the prior art, the technical solution of the present invention has the following technical effects: the invention introduces a magnetic field to magnetize the water film, thereby changing the wettability of the water film and further increasing the lubrication performance of the water film. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic structural diagram of a device for determining parameters for preparing a water film according to an embodiment of the present invention;

[0026] Figure 2 yes Figure 1 A top view of the center positioning grid simulation mechanism;

[0027] Figure 3 yes Figure 2 A cross-sectional view of the center positioning grid simulation mechanism;

[0028] Figure 4 yes Figure 1 Schematic diagram of the connection mechanism between the middle traction mechanism and the clamping head;

[0029] In the figure, a support frame 100, a traction mechanism 200, a first speed measuring mechanism 300, a force measuring mechanism 400, a spacer grid simulation mechanism 500, a water spraying mechanism 600, a magnetic field mechanism 700, a zirconium alloy cladding tube 800, a humidity regulator 900,

[0030] Clamping head 220 , guide rod 230 , steel cam 510 , spring 520 . DETAILED DESCRIPTION

[0031] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0032] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0033] Example

[0034] The method for preparing a water film on the surface of a nuclear fuel rod disclosed in the present invention comprises the following steps: spraying water onto the surface of a zirconium alloy cladding tube to form a lubricating water layer and magnetizing the lubricating water layer or a water source of the lubricating water layer through a magnetic field, so that the water in the lubricating water layer is more evenly distributed on the surface of the zirconium alloy cladding tube to form a friction-reducing water film. The present invention changes the wettability of the water film through magnetization, thereby forming a friction-reducing water film with a small friction coefficient, reducing the wear of the zirconium alloy cladding tube when rubbing against other objects (such as steel convexities and springs in a spacer grid), thereby ensuring the integrity of the zirconium alloy cladding tube, and further ensuring the safety of the fuel rods.

[0035] The magnetic field in this embodiment is a steady-state magnetic field. There are many specific ways to generate the magnetic field, such as using neodymium iron boron magnets.

[0036] In some embodiments, the water source of the lubricating water layer can be magnetized first, and then the magnetized water can be sprayed onto the surface of the zirconium alloy cladding tube to form a friction-reducing water film, but generally a longer magnetization time is required to obtain a more ideal pressure-reducing water film. In some embodiments, water can be sprayed onto the surface of the zirconium alloy cladding tube to form a lubricating water layer, and then the lubricating water layer can be magnetized by a magnetic field. Since the lubricating water layer formed by spraying water on the surface of the zirconium alloy cladding tube after spraying is a thinner water layer, the magnetization time is significantly shortened.

[0037] Taking the example of first spraying water on the surface of the zirconium alloy cladding tube to form a lubricating water layer and then magnetizing the lubricating water layer through a magnetic field, in some embodiments, the magnetic field rotates around the axis of the zirconium alloy cladding tube so that the water film is evenly distributed along the circumference of the zirconium alloy cladding tube, for example, the magnetic field is fixed and the zirconium alloy cladding tube rotates around its axis. In some embodiments, the magnetic field moves along the axis of the zirconium alloy cladding tube so that the water film is evenly distributed along the axial direction of the zirconium alloy cladding tube. In some embodiments, the magnetic field rotates around the axis of the zirconium alloy cladding tube and moves along the axis of the zirconium alloy cladding tube, for example, the magnetic field is fixed and the zirconium alloy cladding tube rotates around its axis. In this way, the rotation of the zirconium alloy cladding tube can be used to assist the water layer to be more evenly distributed along its circumferential direction.

[0038] In some embodiments, an atomizing nozzle may be used to spray water onto the surface of the zirconium alloy cladding tube, and the water may be sprayed onto the surface of the zirconium alloy cladding tube in the form of water mist, so as to form a relatively dispersed primary distribution. In some embodiments, the humidity of the gas around the surface of the zirconium alloy cladding tube may also be adjusted to reduce the evaporation rate of the friction-reducing water film on the surface of the zirconium alloy cladding tube, and ensure that the friction-reducing water film is in an intact state during the friction between the zirconium alloy cladding tube and the steel convex of the spacer grid.

[0039] Please refer to Figure 1, which shows a specific structure of the device for determining the parameters of preparing water film of the present invention, the present invention comprises a support frame 100, a traction mechanism 200, a first speed measuring mechanism 300, a force measuring mechanism 400, a positioning grid simulation mechanism 500, a water spraying mechanism 600 and a magnetic field mechanism 700, wherein the support frame 100 is used as a carrier of other components, the traction mechanism 200 is carried on the support frame 100, and can move axially, thereby driving the zirconium alloy cladding tube 800 to move along its axial direction, and the traction mechanism 200 can adopt an existing tensile testing machine; the first speed measuring mechanism 300 is used to determine the speed of driving the zirconium alloy cladding tube 800 to move along its axial direction, and in specific implementation, it can be fixedly connected to the moving end of the traction mechanism 200, Thereby, it moves synchronously with the moving end of the traction mechanism 200, which is convenient for speed measurement. There are many kinds of specific speed measurement equipment, which can be selected according to needs; the positioning grid simulation mechanism 500 is used to apply friction force to the peripheral side wall of the zirconium alloy cladding tube 800; the force measuring mechanism 400 is used to measure the traction force of the traction mechanism 200 on the zirconium alloy cladding tube 800, and the friction force can be obtained by subtracting the gravity of the zirconium alloy cladding tube 800 from this traction force; the water spraying mechanism 600 is used to spray water on the surface of the zirconium alloy cladding tube 800 to form a lubricating water layer; the magnetic field mechanism 700 is used to generate a magnetic field around the zirconium alloy cladding tube 800 and magnetize the lubricating water layer or the water source of the lubricating water layer through the magnetic field, so that the water distribution of the lubricating water layer is more uniform, forming a friction-reducing water film.

[0040] In the following embodiments, the magnetic field mechanism 700 is used to magnetize the lubricating water layer as an example for explanation. During the experiment, one end of the zirconium alloy cladding tube 800 passes through the positioning grid simulation mechanism 500. By adjusting the positioning grid simulation mechanism 500, its pressure on the wall of the zirconium alloy cladding tube 800 can be obtained. The water spraying mechanism 600 and the magnetic field mechanism 700 form a friction-reducing water film on the wall of the zirconium alloy cladding tube 800. Then, the zirconium alloy cladding tube 800 is pulled axially by the traction mechanism 200. The friction force of the positioning grid simulation mechanism 500 on the zirconium alloy cladding tube 800 can be obtained. By comparing the friction force, its friction coefficient can be determined, and the parameter with the smallest friction coefficient is selected as the operating parameter for preparing the decompression water film. When screening parameters, the magnetic field size, magnetization time, and axial movement speed can be used as single factor variables to determine the optimal operating parameters.

[0041] In some embodiments, the spacer grid simulation mechanism 500 is as follows Figure 2 and Figure 3 As shown, it includes a steel protrusion 510 and a spring 520 , which are arranged around the circumference of the zirconium alloy cladding tube 800 , and the spring 520 pushes the zirconium alloy cladding tube 800 to abut against the steel protrusion 510 .

[0042] In some embodiments, the water spray mechanism 600 uses an atomizing nozzle to spray water mist onto the surface of the zirconium alloy cladding tube 800. In some embodiments, there are multiple atomizing nozzles distributed around the circumference of the zirconium alloy cladding tube 800, so that the lubricating water layer can be more uniform.

[0043] In some embodiments, the traction mechanism 200 simultaneously drives the zirconium alloy clad tube 800 to rotate along its center line, and is equipped with a second speed measuring mechanism for measuring the rotation speed of the zirconium alloy clad tube relative to the magnetic field, so that the magnetic field mechanism 700 can uniformly magnetize the lubricating water layer on the outer wall of the zirconium alloy clad tube 800, thereby obtaining a better friction reduction effect. In order to enable the traction mechanism 200 to smoothly drive the zirconium alloy clad tube 800 to rotate, the lower end of the traction mechanism 200 is connected to the clamping head 220 through the force measuring mechanism 400, and the clamping head 220 clamps one end of the zirconium alloy clad tube 800. The clamping head 220 and the lower end of the traction mechanism 200 are both provided with flanges, and the guide rod 230 is inserted into the flange, so that the clamping head 220 and the lower end of the traction mechanism can move axially, thereby adapting to the axial displacement of the force measuring mechanism 400. At the same time, this structure can prevent the clamping head 220 and the lower end of the traction mechanism 200 from rotating relative to each other.

[0044] In some embodiments, a thermometer and humidity regulator 900 is further included to adjust the humidity of the gas around the surface of the zirconium alloy cladding tube so that the friction-reducing water film is intact during the friction between the zirconium alloy cladding tube 800 and the spacer grid simulation mechanism 500 .

[0045] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for preparing a water film on the surface of a nuclear fuel rod, characterized in that: The method comprises the following steps: spraying water onto the surface of the zirconium alloy cladding tube to form a lubricating water layer and magnetizing the lubricating water layer or a water source of the lubricating water layer through a magnetic field, so that the water in the lubricating water layer is more evenly distributed on the surface of the zirconium alloy cladding tube to form a friction-reducing water film.

2. The method for preparing a water film on the surface of a nuclear fuel rod according to claim 1, characterized in that: The magnetic field is a steady-state magnetic field.

3. The method for preparing a water film on the surface of a nuclear fuel rod according to claim 1, characterized in that: The magnetic field magnetizes the lubricating water layer, and during the magnetization process, the magnetic field rotates around the axis of the zirconium alloy cladding tube.

4. The method for preparing a water film on the surface of a nuclear fuel rod according to claim 1, characterized in that: The magnetic field magnetizes the lubricating water layer, and during the magnetization process, the magnetic field rotates around the axis of the zirconium alloy cladding tube, so that the water film is evenly distributed along the circumference of the zirconium alloy cladding tube.

5. The method for preparing a water film on the surface of a nuclear fuel rod according to claim 1, characterized in that: The magnetic field magnetizes the lubricating water layer, and during the magnetization process, the magnetic field rotates around the axis of the zirconium alloy cladding tube and moves along the axis of the zirconium alloy cladding tube.

6. The method for preparing a water film on the surface of a nuclear fuel rod according to claim 1, characterized in that: The method also includes adjusting the humidity of the gas around the surface of the zirconium alloy cladding tube to reduce the evaporation rate of the friction-reducing water film on the surface of the zirconium alloy cladding tube.

7. A device for determining parameters for preparing a water film, characterized in that: include: A traction mechanism, used for driving the zirconium alloy cladding tube to move along its axial direction; The first speed measuring mechanism is used to measure the speed of driving the zirconium alloy cladding tube to move along its axial direction; A force measuring mechanism, used to measure the traction force of the traction mechanism on the zirconium alloy cladding tube, thereby determining the friction force; A spacer grid simulation mechanism for applying friction force to the peripheral side wall of the zirconium alloy cladding tube; A water spraying mechanism, used for spraying water onto the surface of the zirconium alloy cladding tube to form a lubricating water layer; The magnetic field mechanism is used to generate a magnetic field around the zirconium alloy cladding tube and magnetize the lubricating water layer or the water source of the lubricating water layer through the magnetic field, so that the water distribution of the lubricating water layer is more uniform, forming a friction-reducing water film.

8. The device for determining parameters for preparing a water film according to claim 7, characterized in that: The water spraying mechanism adopts an atomizing nozzle.

9. The device for determining parameters for preparing a water film according to claim 7, characterized in that: The traction mechanism simultaneously drives the zirconium alloy cladding tube to rotate along its center line. The experimental device also includes a second speed measuring mechanism for measuring the rotation speed of the zirconium alloy cladding tube relative to the magnetic field.

10. The device for determining parameters for preparing a water film according to claim 7, characterized in that: The experimental device also includes a humidity adjustment mechanism for adjusting the humidity of the gas around the surface of the zirconium alloy cladding tube.

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