Liquid metal target nozzle and manufacturing method thereof

Abstract

The invention relates to a liquid metal target nozzle and a manufacturing method thereof.The nozzle comprises a nozzle inlet pipe and a nozzle outlet pipe located at the two ends and a nozzle body located in the middle section, and liquid metal enters from the nozzle inlet pipe, flows through the nozzle body and then flows out from the nozzle outlet pipe; a beam bombardment area of the liquid metal film is formed in the nozzle body, the beam bombardment area is of a cambered surface structure sunken towards the interior of the nozzle body, and when liquid metal flows through the cambered surface area, the liquid metal flows along the inner surface of the area to form the uniform and stable liquid metal film. The arc surface structure which is sunken towards the interior of the nozzle main body is formed in the beam bombardment area, and a uniform and stable liquid metal film can be formed by utilizing the Coanda effect; due to the fact that the nozzle is a special-shaped part, the integrated machining difficulty of a machine tool is large, the invention provides a nozzle machining and manufacturing method at the same time, under the condition that normal use can be guaranteed, the nozzle manufacturing period is shortened, and manpower and material resources are saved.

Description

Technical Field

[0001] The invention belongs to the neutron generation target technology in particle physics scientific research, and specifically relates to a liquid metal target nozzle structure and a manufacturing method thereof. Background Art

[0002] In the process of particle physics scientific research, nuclear reactions will occur when particle beams bombard neutron-producing targets. The nuclear reaction process can be inferred by detecting the data generated by the nuclear reactions. As the beam power increases, a large amount of heat will be generated in the nuclear reaction process. Conventional neutron-producing targets generally use solid targets or gaseous targets. For example, the China Spallation Neutron Source (CSNS) uses solid tungsten targets with a beam power of 160kW; gas deuterium targets and gas tritium targets are commonly used in high-voltage multipliers. Solid targets have limited heat dissipation capacity, and gaseous targets have limited neutron yield increases. These two targets limit the increase in particle beam power due to their own characteristics. Compared with gaseous targets, liquid targets have a higher probability of nuclear reactions during beam bombardment and a higher neutron yield; compared with solid targets, liquid targets are in a flowing state. Through a specific heat exchange structure, their heat dissipation capacity can be effectively improved, the beam power can be increased, and rich nuclear data can be obtained to meet the domestic demand for richer nuclear data. In liquid targets, liquid metal films with stable and uniform wall thickness can often effectively improve the quality of neutron production. To obtain liquid metal films with stable and uniform wall thickness, the liquid nozzle structure plays a decisive role. Therefore, to obtain neutron production targets with stable and uniform wall thickness, it is necessary to design and manufacture an excellent nozzle structure. The liquid metal film part formed by the current nozzle structure is an arc transition, and the beam bombardment part is a convex structure protruding to the outside of the nozzle body. When the flow rate of the fluid is too slow, the fluid may separate from the convex structure above the convex structure. Summary of the invention

[0003] The purpose of the present invention is to provide a liquid metal target nozzle capable of forming a stable and uniform liquid metal film and a manufacturing method thereof, so as to solve the problems of difficult heat dissipation of solid targets, limited improvement of neutron yield of gaseous targets and difficult nozzle processing and manufacturing.

[0004] The technical solution of the present invention is as follows: a liquid metal target nozzle, comprising a nozzle inlet pipe and a nozzle outlet pipe located at both ends, and a nozzle body located in the middle section, wherein liquid metal enters from the nozzle inlet pipe, flows through the nozzle body, and flows out from the nozzle outlet pipe, forming a beam bombardment area of ​​a liquid metal film in the nozzle body, wherein the beam bombardment area is an arc surface structure recessed into the interior of the nozzle body, and when the liquid metal flows through the arc surface area recessed into the interior of the nozzle body, it flows along the inner surface of the area to form a uniform and stable liquid metal film.

[0005] Further, in a specific embodiment, in the liquid metal target nozzle as described above, the nozzle inlet pipe and the nozzle outlet pipe are both circular tube structures, and the nozzle inlet pipe and the nozzle outlet pipe are connected to the nozzle body through an upper transition section and a lower transition section respectively.

[0006] Furthermore, the upper transition section and the lower transition section are structures that transition from a round opening to a square opening.

[0007] Furthermore, in a specific embodiment, in the liquid metal target nozzle as described above, the upper part of the nozzle body is a flat square tube, the upper port of the flat square tube is wide, the lower port is narrow, the middle part is an arc-shaped, and the lower port extends to the outside of the nozzle body. The outer edge of the lower port is connected to the beam bombardment area of ​​the nozzle body, and the liquid metal forms a thin film after flowing out of the lower port.

[0008] Furthermore, in a specific embodiment, in the liquid metal target nozzle as described above, the lower part of the nozzle body is surrounded by an arc plate and three flat plates, the arc plate and the flat plates on both sides thereof are an integral structure with the corresponding surfaces of the flat square tube on the upper part of the nozzle body, the arc surface structure recessed toward the inside of the nozzle body is formed on the arc plate, and a notch for the beam to pass through is provided on the flat plate opposite to the arc plate.

[0009] Further, in a specific embodiment, in the liquid metal target nozzle as described above, the upper port of the flat square tube of the nozzle body is connected to the square port of the upper transition section, and the lower outlet of the nozzle body is connected to the square port of the lower transition section.

[0010] Further, in a specific embodiment, in the liquid metal target nozzle as described above, the upper opening of the nozzle inlet pipe and the lower opening of the nozzle outlet pipe are respectively provided with a step-like structure for positioning the entire nozzle in a plane.

[0011] Further, in a specific embodiment, as described above for the liquid metal target nozzle, the upper opening of the nozzle inlet pipe or the lower opening of the nozzle outlet pipe is circumferentially provided with a plurality of square openings for positioning the entire nozzle in the circumferential direction.

[0012] Furthermore, in a specific embodiment, the liquid metal target nozzle as described above is made of 304 stainless steel.

[0013] The present invention further provides a method for manufacturing the liquid metal target nozzle, comprising:

[0014] The processing of the nozzle inlet pipe and the nozzle outlet pipe uses a hollow round pipe as the raw material, one end of the round pipe is turned, and the other end is forged, and the forged end forms a transition section, which is a structure that transitions from a round mouth to a square mouth;

[0015] Processing of the nozzle body: three flat plates and two arc plates are processed according to the structure of the nozzle body. The arc plates are rolled into the required shape by a plate rolling machine, and the five plates are welded into the nozzle body; wherein, the first arc plate, the upper part of the second arc plate, the upper part of the first flat plate, and the upper part of the second flat plate are surrounded to form a flat square tube at the upper part of the nozzle body; the lower part of the second arc plate, the lower part of the first flat plate, the lower part of the second flat plate, and the third flat plate are surrounded to form the lower part of the nozzle body, and a curved surface structure concave toward the inside of the nozzle body is formed at the lower part of the second arc plate as a beam bombardment area, and a notch for the beam to pass through is provided on the third flat plate;

[0016] The nozzle inlet pipe, the nozzle outlet pipe and the nozzle body are welded to form an integral nozzle.

[0017] Furthermore, in the manufacturing method of the liquid metal target nozzle as described above, the circular openings of the nozzle inlet pipe and the nozzle outlet pipe are both turned into steps; and the circular opening of the nozzle inlet pipe or the nozzle outlet pipe is processed into a plurality of square openings along the circumferential direction.

[0018] The beneficial effects of the present invention are as follows: the liquid metal target nozzle provided by the present invention forms an arc surface structure recessed toward the inside of the nozzle body in the beam bombardment area, and the liquid metal flows along the inner surface of the area to form a uniform and stable liquid metal film by utilizing the Coanda effect; since the nozzle is a special-shaped part, it is difficult to integrate it with a machine tool. The present invention also proposes a nozzle processing and manufacturing method, which shortens the nozzle manufacturing cycle and saves manpower and material resources while ensuring normal use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a liquid metal target nozzle in a specific embodiment of the present invention;

[0020] Figure 2 It is a schematic diagram of the structure of the nozzle inlet pipe in a specific embodiment of the present invention;

[0021] Figure 3 It is a schematic diagram of the structure of the nozzle outlet pipe in a specific embodiment of the present invention;

[0022] Figure 4 It is a schematic diagram of the structure of various parts of the nozzle body in a specific embodiment of the present invention;

[0023] Figure 5 It is a schematic diagram of the structure of the nozzle body after the various parts are assembled in a specific embodiment of the present invention;

[0024] Figure 6 It is a schematic longitudinal section diagram of the target chamber and the nozzle assembly in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] The present invention provides a nozzle for forming a liquid metal film for particle beam bombardment, such as Figure 1 As shown, it includes a nozzle inlet pipe 1 and a nozzle outlet pipe 3 located at both ends, and a nozzle body 2 located in the middle section. Liquid metal enters from the nozzle inlet pipe 1, flows through the nozzle body 2, and flows out from the nozzle outlet pipe 3, forming a beam bombardment area of ​​a liquid metal film in the nozzle body 2, wherein the beam bombardment area is an arc surface structure recessed into the inside of the nozzle body. When the liquid metal flows through the arc surface area recessed into the inside of the nozzle body, it flows along the inner surface of the area to form a uniform and stable liquid metal film.

[0027] The nozzle structure of the present invention is composed of three parts: upper and lower circular tubes and a tetrahedral nozzle body in the middle. The upper and lower circular tubes are liquid transition areas, and the middle nozzle body is a beam bombardment area for forming a liquid metal film. The beam bombardment area is a curved surface structure that is concave toward the inside of the nozzle body. When liquid metal flows through this part, it is conducive to forming a uniform and stable liquid metal film. The stable and uniform liquid film helps to improve the neutron yield and neutron quality.

[0028] The present invention utilizes the Coanda effect of fluid, which is also called the wall attachment effect. It refers to the tendency of fluid (water flow or air flow) to leave the original flow direction and flow along the protruding surface of an object during the flow process. In the design of the present invention, the wall surface of the beam bombardment area is an arc surface, which is concave to the inside of the nozzle body, which essentially forms a bulge on the inner wall of the nozzle body. When the liquid metal flows through this area, it tends to flow along the bulge, thereby forming a uniform and stable film on the inner wall surface. The design purpose of the nozzle is to form the liquid metal film for the particle beam to bombard.

[0029] Example 1

[0030] In this embodiment, the nozzle inlet pipe 1 and the nozzle outlet pipe 3 are both circular tube structures, and the nozzle inlet pipe 1 and the nozzle outlet pipe 3 are connected to the nozzle body through the upper transition section 4 and the lower transition section 5, respectively. Figure 2 , Figure 3As shown. Specifically, the nozzle inlet pipe 1 and the nozzle outlet pipe 3 are both made of hollow circular tubes as raw materials. One end of the hollow circular tube is turned, and the other end is forged. A transition section is formed at the forged end, and the transition section is a structure that transitions from a round mouth to a square mouth. The nozzle body 2 is a tetrahedral structure, and the upper and lower openings are both rectangular square mouths. The nozzle inlet pipe 1 is connected to the upper opening of the nozzle body through the upper transition section 4, and the nozzle outlet pipe 3 is connected to the lower opening of the nozzle body through the lower transition section 5. The liquid metal enters from the nozzle inlet pipe 1, flows through the nozzle body 2, and then flows out from the nozzle outlet pipe 3.

[0031] The upper opening of the nozzle inlet pipe 1 and the lower opening of the nozzle outlet pipe 3 are respectively provided with a step-shaped structure. Figure 2 , Figure 3 , which is used to position the entire nozzle in a plane. That is to say, after the liquid metal target nozzle is loaded into the vacuum target chamber, the upper and lower ends are both arranged in corresponding positioning holes. Since the upper end opening of the nozzle inlet pipe and the lower end opening of the nozzle outlet pipe are both provided with a step-like structure, the upper and lower ends inserted into the positioning holes can play a role of fixing in the plane, limiting the up and down and left and right movement of the nozzle. However, since the positioning hole is a circular hole, the nozzle may rotate. Therefore, several square openings can be processed circumferentially at the upper end opening of the nozzle inlet pipe or the lower end opening of the nozzle outlet pipe for positioning the entire nozzle in the circumferential direction. That is, the protrusions at the corresponding positions in the positioning hole can be embedded in the square openings, so that the nozzle cannot rotate in the circumferential direction. In this embodiment, the square opening 6 for circumferential positioning is arranged at the lower end opening of the nozzle outlet pipe 3, such as Figure 3 shown.

[0032] The nozzle body 2 of this embodiment is a tetrahedral structure. The upper part of the nozzle body is a flat square tube. The upper port of the flat square tube is wide, the lower port is narrow, and the middle part is an arc surface. The lower port extends to the outside of the nozzle body. The outer edge of the lower port is connected to the beam bombardment area of ​​the nozzle body. The liquid metal forms a thin film after flowing out from the lower port. From the nozzle inlet tube downward, the round tube first transitions to a square tube, and then forms a flat square tube from the square tube. The main purpose is to allow liquid metal to flow through it to form a liquid metal film. Therefore, the lower port of the flat square tube should be very narrow, and the middle part of the flat square tube is an arc surface. The lower port deviates to the outside so that the liquid metal can flow stably therein, and then flow out evenly from the narrow slit of the lower port to form a liquid metal film. The outer edge of the lower port is connected to the beam bombardment area of ​​the nozzle body. The film in the area bombarded by the particle beam needs to be as uniform in thickness as possible and have a smooth surface. The lower part of the nozzle body is surrounded by an arc plate and three flat plates. The arc plate and the flat plates on both sides are in an integral structure with the corresponding surfaces of the flat square tube on the upper part of the nozzle body (i.e., each corresponding surface is a plate extending from top to bottom as a whole). An arc surface structure recessed toward the inside of the nozzle body is formed on the arc plate, and a notch for beam flow to pass through is provided on the flat plate arranged opposite to the arc plate. The present invention draws on the Coanda effect of fluids, and designs an inwardly bulging structure on the inner wall of the area where the liquid forms a film. When the liquid metal flows through this area, it tends to flow along the bulging part, thereby forming a uniform and stable film on the inner wall surface.

[0033] In this embodiment, the components of the nozzle body are as follows: Figure 4 As shown, it includes the first flat plate and the second flat plate I, the third flat plate II, the first curved plate III, and the second curved plate IV of the same shape. Figure 5 As shown, the first arc plate III, the upper part of the second arc plate IV, the upper part of the first flat plate I, and the upper part of the second flat plate I enclose the flat square tube of the upper part of the nozzle body; the lower part of the second arc plate IV, the lower part of the first flat plate I, the lower part of the second flat plate I, and the third flat plate II enclose the lower part of the nozzle body. The left and right sides of the second arc plate IV are respectively connected to the first flat plate and the second flat plate. The first flat plate and the second flat plate have the same shape and are symmetrically arranged, forming the closed surfaces on both sides of the nozzle body. The first arc plate III and the upper part of the second arc plate IV are designed correspondingly, forming an arc cavity of the flat square tube of the upper part of the nozzle body. The lower part of the second arc plate IV forms an arc surface structure 7 that is recessed into the inside of the nozzle body as the beam bombardment area. The third flat plate II is arranged opposite to the second arc plate IV. In this embodiment, a circular arc notch is formed at the upper end of the third flat plate II, and the circular arc notch is directly opposite to the arc surface structure 7 on the second arc plate IV. The beam bombards the liquid metal film formed on the inner wall of the nozzle in the corresponding area through the notch.

[0034] The structure of the present invention can effectively form a liquid metal film for particle beam bombardment. Compared with solid targets, the heat generated during the particle beam bombardment of liquid targets can be carried away by the flow of liquid and then by the subsequent heat exchange structure, which is conducive to improving the particle beam power. Compared with gaseous targets, the fluid medium contact of liquid targets is denser, and particle beam bombardment of liquid targets can increase the probability of nuclear reaction, which is conducive to increasing neutron yield.

[0035] Example 2

[0036] This embodiment further describes a method for manufacturing a liquid metal target nozzle.

[0037] The liquid metal target nozzle of this embodiment is made of 304 stainless steel, and the specific manufacturing method includes:

[0038] The processing of the nozzle inlet pipe and the nozzle outlet pipe uses a hollow round pipe as the raw material, one end of the round pipe is turned, and the other end is forged, and the forged end forms a transition section, which is a structure that transitions from a round mouth to a square mouth; the circular openings of the nozzle inlet pipe and the nozzle outlet pipe are turned into steps for positioning the entire nozzle in a plane; the circular opening of the nozzle inlet pipe or the nozzle outlet pipe is processed with a plurality of square openings along the circumference for positioning the entire nozzle in the circumferential direction. In this embodiment, a plurality of square openings are processed at the lower end opening of the nozzle outlet pipe, and the square openings are evenly arranged along the circumference of the lower end opening of the nozzle outlet pipe.

[0039] The nozzle body is processed by processing three flat plates and two arc plates according to the structure of the nozzle body. The arc plates are rolled into the required shape by a plate rolling machine, and the five plates are welded together to form the nozzle body. Among them, the first arc plate, the upper part of the second arc plate, the upper part of the first flat plate, and the upper part of the second flat plate form a flat square tube at the upper part of the nozzle body; the lower part of the second arc plate, the lower part of the first flat plate, the lower part of the second flat plate, and the third flat plate form the lower part of the nozzle body. A curved surface structure that is concave to the inside of the nozzle body is formed at the lower part of the second arc plate as a beam bombardment area, and a notch is provided on the third flat plate for the beam to pass through. Specifically, the first flat plate and the second flat plate are welded on the left and right sides of the second arc plate respectively. The first flat plate and the second flat plate have the same shape and are symmetrically arranged, forming the closed surfaces on both sides of the nozzle body. The upper parts of the first arc plate and the second arc plate are designed correspondingly, forming an arc cavity of the flat square tube at the upper part of the nozzle body. The lower part of the second arc plate forms a curved surface structure that is concave to the inside of the nozzle body as a beam bombardment area. The third plate is arranged opposite to the second arc plate and is welded to the first plate and the second plate respectively. In this embodiment, an arc notch is processed on the upper end of the third plate, and the arc notch is directly opposite to the arc surface structure of the beam bombardment area on the second arc plate. The beam bombards the liquid metal film formed on the inner wall surface of the nozzle in the corresponding area through the notch. Five metal plates are welded to form the nozzle body.

[0040] The nozzle inlet pipe, the nozzle outlet pipe and the nozzle body are welded to form an integral nozzle.

[0041] like Figure 6 As shown, in this embodiment, the liquid metal target nozzle 8 is installed in the vacuum target chamber 9 by means of the step structures of the nozzle inlet pipe and the nozzle outlet pipe for planar positioning and the square mouth of the nozzle outlet pipe for circumferential positioning, so as to form a liquid metal film of the liquid target for particle beam bombardment to produce neutrons.

[0042] Those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. Thus, if these variations and use adaptations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and use adaptations.

[0043] The above embodiments are merely illustrative of the present invention, and the present invention may also be implemented in other specific ways or other specific forms without departing from the gist or essential features of the present invention. Therefore, the described embodiments should be considered illustrative rather than restrictive in any respect. The scope of protection of the present invention should be described by the claims, and any changes equivalent to the intent and scope of the claims should also be included within the scope of the present invention.

Claims

1. A liquid metal target nozzle, comprising a nozzle inlet pipe and a nozzle outlet pipe at both ends, and a nozzle body located in the middle section, wherein liquid metal enters through the nozzle inlet pipe, flows through the nozzle body, and flows out through the nozzle outlet pipe, forming a beam bombardment area of ​​a liquid metal film in the nozzle body, characterized in that: The beam bombardment area is a curved surface structure that is recessed into the nozzle body. When the liquid metal flows through the curved surface area that is recessed into the nozzle body, it flows along the inner surface of the area to form a uniform and stable liquid metal film.

2. The liquid metal target nozzle according to claim 1, characterized in that: The nozzle inlet pipe and the nozzle outlet pipe are both circular tube structures, and the nozzle inlet pipe and the nozzle outlet pipe are connected to the nozzle body through an upper transition section and a lower transition section respectively.

3. The liquid metal target nozzle according to claim 2, characterized in that: The upper transition section and the lower transition section are structures that transition from a round opening to a square opening.

4. The liquid metal target nozzle according to claim 1 or 2, characterized in that: The upper part of the nozzle body is a flat square tube, the upper port of the flat square tube is wide, the lower port is narrow, the middle part is an arc surface, the lower port extends to the outside of the nozzle body, the outer edge of the lower port is connected to the beam bombardment area of ​​the nozzle body, and the liquid metal flows out of the lower port to form a film.

5. The liquid metal target nozzle according to claim 4, characterized in that: The lower part of the nozzle body is surrounded by an arc plate and three flat plates. The arc plate and the flat plates on both sides thereof form an integral structure with the corresponding surfaces of the flat square tube on the upper part of the nozzle body. The arc surface structure recessed toward the inside of the nozzle body is formed on the arc plate, and a notch for the beam to pass through is provided on the flat plate arranged opposite to the arc plate.

6. The liquid metal target nozzle according to claim 5, characterized in that: The upper port of the flat square tube of the nozzle body is connected to the square port of the upper transition section, and the lower outlet of the nozzle body is connected to the square port of the lower transition section.

7. The liquid metal target nozzle according to claim 1, characterized in that: The upper end opening of the nozzle inlet pipe and the lower end opening of the nozzle outlet pipe are respectively provided with a step-shaped structure for positioning the entire nozzle in a plane.

8. The liquid metal target nozzle according to claim 1 or 7, characterized in that: The upper end opening of the nozzle inlet pipe or the lower end opening of the nozzle outlet pipe is circumferentially provided with a plurality of square openings for positioning the entire nozzle in the circumferential direction.

9. The liquid metal target nozzle according to claim 1, characterized in that: Made of 304 stainless steel.

10. A method for manufacturing a liquid metal target nozzle according to any one of claims 1 to 9, characterized in that: include: The processing of the nozzle inlet pipe and the nozzle outlet pipe uses a hollow round pipe as the raw material, one end of the round pipe is turned, and the other end is forged, and the forged end forms a transition section, which is a structure that transitions from a round mouth to a square mouth; The nozzle body is processed by processing three flat plates and two curved plates according to the structure of the nozzle body. The curved plates are rolled into the required shape by a plate rolling machine, and the five plates are welded into the nozzle body; wherein, the first curved plate, the upper part of the second curved plate, the upper part of the first flat plate, and the upper part of the second flat plate are surrounded to form a flat square tube at the upper part of the nozzle body; The lower part of the second arc plate, the lower part of the first flat plate, the lower part of the second flat plate and the third flat plate enclose the lower part of the nozzle body, a curved surface structure recessed toward the inside of the nozzle body is formed at the lower part of the second arc plate as a beam bombardment area, and a notch is provided on the third flat plate for the beam to pass through; The nozzle inlet pipe, the nozzle outlet pipe and the nozzle body are welded to form an integral nozzle.

11. The method for manufacturing a liquid metal target nozzle according to claim 10, characterized in that: The circular openings of the nozzle inlet pipe and the nozzle outlet pipe are both turned into step shapes; the circular opening of the nozzle inlet pipe or the nozzle outlet pipe is processed into a plurality of square openings along the circumferential direction.

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