Alkali metal heat pipe filling device

Abstract

The utility model discloses an alkali metal heat pipe filling device, and relates to the technical field of high-temperature heat pipes. The device specifically comprises a brazing box, a heat pipe, a gas system and a working medium filling system, the brazing box comprises a vacuum main container and a push rod, and the push rod can be horizontally moved into or out of the vacuum main container; the heat pipe is arranged in the brazing box and comprises a cavity and an end plug, the cavity is horizontally arranged in the vacuum main container, the end plug is connected with the end, facing the brazing box, of the push rod, and the push rod and the cavity are coaxially arranged; the gas system is connected with the brazing box; the working medium filling system is connected to the brazing box and inputs the molten working medium into the cavity. The push rod and the heat pipe are coaxially arranged, when the heat pipe and the end plug need seal welding, the push rod horizontally drives the end plug to be assembled at the open end of the heat pipe, the heat pipe is kept communicated with the vacuum main container before seal welding, in the continuous, controlled and pollution-free process, working medium filling and end plug seal welding are completed, the vacuum degree of the heat pipe before welding is improved, and the working efficiency is improved. Meanwhile, the welding quality of the end plug is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of high-temperature heat pipes, in particular to an alkali metal heat pipe filling device. Background Art

[0002] Liquid metal high-temperature heat pipes have passive characteristics and do not require other power machinery to transport heat energy. The system is simple and lightweight, with strong heat transfer capabilities. In addition, the heat pipes are independent of each other, which can avoid single point failures and provide redundant safety protection. Therefore, liquid metal high-temperature heat pipes are an important research object for space nuclear reactor power core heat transfer systems and radiation radiators.

[0003] At present, the working fluid filling and sealing of high-temperature heat pipes using liquid alkali metals such as sodium, potassium, and lithium as working fluids are very important. Liquid alkali metals such as sodium, potassium, and lithium are active chemical elements and are very easy to react with elements such as oxygen, carbon, and nitrogen in the air. They are also easy to react with water vapor to form impurity compounds. The presence of these compounds in the heat pipe working fluid will lead to accelerated corrosion of the structural material and blockage of the working fluid flow channel, causing the heat transfer performance of the heat pipe to deteriorate. Therefore, the working fluid filling and sealing of heat pipes must usually be carried out in a high-purity inert gas protection environment, which places high demands on the equipment and process design for the working fluid filling and sealing.

[0004] In the prior art, during the manufacturing process of heat pipes, the heat pipe shell is generally first processed into a slender tubular structure, and then end plugs are assembled at both ends. The end plugs are an important component of the heat pipe and are used to seal the heat pipe cavity. Before the vacuum operation, the end plugs will be pre-assembled to both ends of the heat pipe cavity. However, at this time, the connection between the end plugs and the cavity is usually detachable or not completely sealed and fixed to facilitate subsequent vacuuming and sealing operations. After the working fluid is filled and vacuuming is completed, the end plugs will be finally sealed and welded to form a permanent sealed structure of the heat pipe.

[0005] However, in the above scheme, the filling of the working fluid needs to be carried out under the protection of high-purity inert gas, and the end plug sealing needs to be carried out in a high vacuum environment to remove residual gas. Since the heat pipe is a slender tubular structure and the end plug and the heat pipe are in an assembled state, it is not conducive to achieving a high vacuum of the heat pipe. The gas impurities remaining inside the heat pipe or adsorbed on the wall of the heat pipe cavity material will seriously affect the startup, heat transfer performance and service life of the finished heat pipe; at the same time, due to the pressure difference between the inside and outside of the heat pipe, it will also cause the subsequent end plug welding deformation problem.

[0006] Therefore, the present application aims to solve the problems of low efficiency in working fluid filling under inert gas protection and end plug sealing welding under high vacuum environment. Utility Model Content

[0007] The utility model discloses a main purpose is to provide a kind of alkali metal heat pipe filling device, in a continuous, controlled and pollution-free process, efficiently complete working medium filling and end plug seal welding, improve the vacuum degree of heat pipe before welding, simultaneously improve the welding quality of end plug.

[0008] In order to realize the above-mentioned purpose, the utility model provides a kind of alkali metal heat pipe filling device, comprising:

[0009] Glove box, its inside is used to provide inert gas environment;

[0010] Brazing box, its inside is used to provide vacuum environment, the support is provided in the brazing box, for fixed heat pipe with cavity, and for pushing the push rod of end plug;

[0011] Sliding door, be set between the glove box and the brazing box, for communicating the glove box with the brazing box in closed state, to transfer heat pipe from the glove box to the brazing box;

[0012] Working medium filling system, communicate with the glove box, for filling molten alkali metal working medium in the cavity placed in the glove box;

[0013] Gas system is connected with the glove box and the brazing box respectively, for supplying inert gas for the glove box, and carrying out vacuumizing to the brazing box;And

[0014] High-frequency induction heating power supply, its inductive component is set in the inside of the brazing box, and corresponds to the cavity and the end plug to be sealed and welded position.

[0015] Further, the brazing box includes a vacuum main container, the push rod is provided on the wall of the vacuum main container, and is sealed and connected with the vacuum main container through a bellows.

[0016] Further, the brazing box further includes a lead screw, the lead screw is rotatably connected to the outer wall of the vacuum main container, and is used to drive the push rod to move axially.

[0017] Further, the push rod is T-shaped.

[0018] Further, including water cooling system, the water cooling system is connected with the gas system and the high-frequency induction heating power supply.

[0019] Further, the gas system includes a vacuum pump set, a second valve, a third valve, an argon cylinder, a fifth valve, a sixth valve, and a gas filling pipeline for connecting each component, the vacuum pump set, the second valve, the third valve and the brazing box are connected in sequence;The argon cylinder, the fifth valve, the sixth valve and the glove box are connected in sequence through the gas filling pipeline.

[0020] Furthermore, the working fluid filling system includes a working fluid storage container, a heating and heat-insulating component, and a weighing system, and the heating and heat-insulating component and the weighing system are both connected to the working fluid storage container.

[0021] The above technical solution has the following advantages:

[0022] The present application places a slender heat pipe in a brazing box so that the heat pipe is placed horizontally, and the end plug is installed on a push rod. The push rod and the heat pipe are coaxially arranged. When the heat pipe and the end plug need to be sealed and welded, the end plug is driven horizontally by the push rod to be assembled on the open end of the heat pipe, so that the heat pipe remains connected to the vacuum main container before sealing and welding. In a continuous, controlled and pollution-free process, the working fluid filling and end plug sealing are completed, thereby improving the vacuum degree of the heat pipe before welding, and at the same time improving the welding quality of the end plug. It can also reduce the pressure difference between the vacuum main container and the cavity to avoid deformation of the end plug welding and affecting the quality of the heat pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0024] Figure 1 This is a schematic diagram of the structural connection of the utility model;

[0025] Figure 2 This is a schematic diagram of the structure of the heat pipe of the utility model;

[0026] Figure 3 This is a schematic structural diagram of the brazing box of the utility model;

[0027] Figure 4 This is a schematic diagram of the structure of the gas system of the utility model;

[0028] Figure 5 This is a structural diagram of the working fluid filling system of the utility model.

[0029] In the figure: 1. Brazing box; 1-1. Vacuum main container; 1-2. Bracket; 1-3. Push rod; 1-4. Bellows; 1-5. Screw; 1-6. Pressure sensor; 2. Glove box; 3. High-frequency induction heating power supply; 4. Gas system; 4-1. Vacuum pump group; 4-2. Vacuum gauge; 4-3. Second valve; 4-4. Third valve; 4-5. Argon cylinder; 4-6. Gas pressure gauge; 4-7. Fifth valve; 4-8. Sixth valve; 4-9. Charging pipe; 5. Water cooling system; 6. Working fluid filling system; 6-1. Working fluid storage container; 6-2. Heating and insulation components; 6-3. Weighing system; 6-4. First valve; 6-5. Filling pipe; 7. Instrumentation and control system; 8. Heat pipe; 8-1. Cavity; 8-2. Alkali metal sodium working fluid; 8-3. End plug; 8-4. Brazing flux; 9. Sliding door. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and do not constitute a limitation to the present invention.

[0031] like Figure 1-Figure 3 As shown, the present invention provides an alkali metal heat pipe filling device. Its core feature is a design that utilizes functional zoning and isolated transfer to solve the challenge of integrating high-purity fluid filling with high-vacuum sealing and welding. The device primarily comprises a glove box 2, a brazing box 1, and a sliding door 9 disposed between the two.

[0032] The interior of the glove box 2 is used to provide a high-purity inert gas environment, such as argon, and is a dedicated area for performing alkali metal working fluid filling operations.

[0033] The interior of the brazing box 1 is used to provide a high vacuum environment and is a dedicated area for removing residual gas from the heat pipe 8 and brazing and sealing the end plug 8-3.

[0034] The sliding door 9 is a key connecting mechanism that can be opened and closed while maintaining a sealed state, so that the heat pipe 8 filled with working fluid can be transferred from the inert gas environment of the glove box 2 to the brazing box 1 without pollution for the subsequent vacuum sealing process.

[0035] In order to achieve the above functions, the device also includes a working fluid filling system 6, a gas system 4, a high-frequency induction heating power supply 3, and an optional water cooling system 5 and an instrumentation and control system 7.

[0036] The following is a detailed description of each system and component:

[0037] like Figure 1 and Figure 5As shown, the working fluid filling system 6 is connected to the glove box 2. In a preferred embodiment, the working fluid filling system 6 includes a working fluid storage container 6-1, a heating and heat-insulating component 6-2 provided on the working fluid storage container 6-1, and a weighing system 6-3 for accurately measuring the working fluid filling amount. The three work together to achieve the storage, melting, and weighing of the sodium working fluid. Specifically, the working fluid filling system 6 is also connected to the instrumentation and control electrical system 7. The working fluid filling system 6 includes a working fluid storage container 6-1, a heating and insulation component 6-2, a weighing system 6-3, a first valve 6-4, and a filling pipe 6-5. The heating and insulation component 6-2 and the weighing system 6-3 are connected between the working fluid storage container 6-1 and the instrumentation and control electrical system 7. The discharge end of the working fluid storage container 6-1 is connected to the filling pipe 6-5, and the first valve 6-4 is installed on the filling pipe 6-5. The sodium metal in the working fluid storage container 6-1 is heated and melted by the heating and insulation component 6-2 to form an alkali metal sodium working fluid 8-2, which enters the heat pipe 8 in the glove box 2 through the first valve 6-4 and the filling pipe 6-5. The weighing system 6-3 measures the mass change of the working fluid storage container 6-1 during the process to obtain the working fluid filling amount. During operation, the heating and heat-insulating component melts the solid sodium working medium in the container into liquid, and accurately fills the alkali metal sodium working medium 8-2 into the cavity 8-1 placed in the glove box 2 through the pipeline 6-5.

[0038] like Figure 1 and Figure 4 As shown, the gas system 4 is connected to the glove box 2 and the brazing box 1, respectively. The gas system 4 includes a vacuum pump group 4-1, a vacuum gauge 4-2, a second valve 4-3, a third valve 4-4, an argon gas cylinder 4-5, a gas pressure gauge 4-6, a fifth valve 4-7, a sixth valve 4-8, and a gas charging pipe 4-9 for connecting the various components. The vacuum pump group 4-1, the second valve 4-3, the third valve 4-4, and the brazing box 1 are sequentially connected. The vacuum gauge 4-2 is connected between the vacuum pump group 4-1 and the second valve 4-3 to measure the state of the vacuum pump group 4-1. The argon gas cylinder 4-5, the fifth valve 4-7, the sixth valve 4-8, and the glove box 2 are sequentially connected via the gas charging pipe 4-9. The gas pressure gauge 4-6 is connected between the argon gas cylinder 4-5 and the fifth valve 4-7 to measure the pressure state of the argon gas cylinder 4-5. The vacuum pump group 4-1 can be a mechanical pump or a molecular pump. By controlling the opening and closing and combination of the second valve 4-3, the third valve 4-4, the fourth valve 4-7 and the fifth valve 4-8, the vacuum pump group 4-1 and the argon bottle 4-5 are connected to the glove box 2 and the brazing box 1 respectively. The gas system 4 can fill and maintain a high-purity argon atmosphere in the glove box 2 and can independently evacuate the brazing box 1 to achieve the high vacuum required for brazing.

[0039] A high-frequency induction heating power supply 3 is used for the final sealing step. Its induction components, such as an induction coil, are located within the brazing box 1 and precisely aligned with the locations of the cavity 8-1 and end plug 8-3 to be sealed. Once the end plug 8-3 is inserted into the cavity 8-1, the power supply is activated, inducing heating of the pre-applied brazing flux 8-4 under a high vacuum environment, melting it and completing the seal.

[0040] like Figure 2 and Figure 3 As shown, in a preferred embodiment, the brazing box 1 includes a vacuum main container 1-1. The heat pipe 8 is horizontally fixed inside the vacuum main container 1-1 by a bracket 1-2. A push rod 1-3 for pushing the end plug 8-3 is inserted into the wall of the vacuum main container 1-1. In order to maintain a high vacuum inside the container while the push rod 1-3 moves, the push rod 1-3 is sealed to the vacuum main container 1-1 via a bellows 1-4. This ensures that the push rod 1-3 can perform linear reciprocating motion inside and outside the container without disrupting the vacuum environment of the vacuum main container 1-1.

[0041] like Figure 3 As shown, to achieve precise control over the movement of the push rod 1-3, the brazing box 1 also includes a lead screw 1-5. This lead screw 1-5 is rotatably connected to the outer wall of the vacuum main container 1-1 and drives the push rod 1-3 through a threaded transmission to achieve smooth axial movement. The operator rotates the handle or a motor drives the lead screw 1-5. Preferably, a pressure sensor 1-6 can be installed between the drive mechanism of the lead screw 1-5 and the push rod 1-3 to monitor and record the preload force during assembly of the end plug 8-3 and the cavity 8-1 in real time, preventing excessive or insufficient assembly stress.

[0042] In a specific embodiment, the push rod 1-3 is T-shaped, one end of which is convenient for stably pushing the end plug 8-3 toward the cavity 8-1, and the other end is a platform, which provides an assembly space for the pressure sensor 1-6, thereby improving the accuracy of the pressure measurement of the push rod 1-3.

[0043] like Figure 2 and Figure 3 As shown, to ensure that the interior of cavity 8-1 is fully evacuated before welding, a gap of, for example, less than 25 mm can be left between the end plug 8-3 and cavity 8-1 before the end plug 8-3 is fully inserted into the cavity 8-1. This ensures that the cavity 8-1 remains connected to the vacuum main container 1-1 before the final welding, allowing the residual gas and adsorbed gas in the cavity to be continuously extracted.

[0044] like Figure 1As shown, in addition, the application can also include a water cooling system 5, which cools the coil of the high-frequency induction heating power supply 3, the pump set of the gas system 4, and the sealing flange of the brazing box 1 and the like through circulating water, to ensure long-term stable operation of the device.

[0045] Work flow example

[0046] The main work flow sequence of the application is as follows:

[0047] A. Place the heat pipe 8 to be filled in the glove box 2; install the end plug 8-3 with brazing agent 8-4 on the push rod 1-3 in the brazing box 1.

[0048] B. Open the sliding door 9, and use the gas system 4 to perform vacuum pumping and argon replacement on the whole connected glove box 2 and brazing box 1, until the internal atmosphere reaches a high-purity argon atmosphere.

[0049] C. In the glove box 2, use the working medium filling system 6 to accurately fill a predetermined amount of molten alkali metal working medium, such as sodium working medium 8-2, into the cavity 8-1.

[0050] D. Transfer the heat pipe 8 filled with the alkali metal working medium from the glove box 2 to the support 1-2 in the brazing box 1 through the sliding door 9 and fix it.

[0051] E. Close and seal the sliding door 9, and use the gas system 4 to independently perform high-vacuum pumping on the brazing box 1.

[0052] F. After the vacuum degree meets the standard (which can be preset according to experimental requirements), drive the lead screw 1-5 to push the push rod 1-3 to move axially, slowly push the end plug 8-3 into the open end of the cavity 8-1 and assemble it in place.

[0053] G. Start the high-frequency induction heating power supply 3, heat the connection between the end plug 8-3 and the cavity 8-1, melt the brazing agent 8-4 and complete the sealing welding.

[0054] H. After the heat pipe 8 is completely cooled, break the vacuum in the brazing box 1 and fill it with atmosphere, and finally take out the finished heat pipe 8.

[0055] The above only describes preferred embodiments of the application, and does not limit the patent range of the application, and any equivalent structural transformation made by using the contents of the application and the drawings, or direct / indirect application in other related technical fields is included in the patent protection range of the application.

Claims

1. An alkali metal heat pipe filling device, characterized in that: include: A glove box (2), the interior of which is used to provide an inert gas environment; A brazing box (1) is provided with a vacuum environment therein. A bracket (1-2) is provided in the brazing box (1) for fixing a heat pipe (8) having a cavity (8-1), and a push rod (1-3) for pushing an end plug (8-3). A sliding door (9) is provided between the glove box (2) and the brazing box (1) and is used to connect the glove box (2) and the brazing box (1) in a sealed state so as to transfer the heat pipe (8) from the glove box (2) to the brazing box (1); A working fluid filling system (6) is communicated with the glove box (2) and is used to fill a cavity (8-1) disposed in the glove box (2) with molten alkali metal working fluid; A gas system (4) is connected to the glove box (2) and the brazing box (1) respectively, and is used to supply inert gas to the glove box (2) and evacuate the brazing box (1); as well as A high-frequency induction heating power supply (3) has an induction component arranged inside the brazing box (1) and corresponding to the position to be sealed and welded between the cavity (8-1) and the end plug (8-3).

2. The alkali metal heat pipe filling device according to claim 1, characterized in that: The brazing box (1) comprises a vacuum main container (1-1), the push rod (1-3) is arranged on the wall of the vacuum main container (1-1), and is sealed and connected to the vacuum main container (1-1) via a bellows (1-4).

3. The alkali metal heat pipe filling device according to claim 2, characterized in that: The brazing box (1) further comprises a lead screw (1-5), which is rotatably connected to the outer wall of the vacuum main container (1-1) and is used to drive the push rod (1-3) to achieve axial movement.

4. The alkali metal heat pipe filling device according to any one of claims 1 to 3, characterized in that: The push rod (1-3) is T-shaped.

5. The alkali metal heat pipe filling device according to claim 1, characterized in that: It comprises a water cooling system (5), wherein the water cooling system (5) is connected to the gas system (4) and the high-frequency induction heating power supply (3).

6. The alkali metal heat pipe filling device according to claim 1, characterized in that: The gas system (4) comprises a vacuum pump group (4-1), a second valve (4-3), a third valve (4-4), an argon gas bottle (4-5), a fifth valve (4-7), a sixth valve (4-8), and an inflation pipe (4-9) for connecting the various components. The vacuum pump group (4-1), the second valve (4-3), the third valve (4-4), and the brazing box (1) are connected in sequence; and the argon gas bottle (4-5), the fifth valve (4-7), the sixth valve (4-8), and the glove box (2) are connected in sequence via the inflation pipe (4-9).

7. The alkali metal heat pipe filling device according to claim 1, characterized in that: The working fluid filling system (6) comprises a working fluid storage container (6-1), a heating and heat-insulating component (6-2), and a weighing system (6-3); the heating and heat-insulating component (6-2) and the weighing system (6-3) are both connected to the working fluid storage container (6-1).

Images