A test device and method for the flow of liquid metal films under the action of induced currents

Abstract

The application provides a test device and method for liquid metal film flow under the action of induced current, and relates to the technical field of fusion reactor thermal flow testing. The application simulates the toroidal strong magnetic field environment of a tokamak by using a split superconducting magnet; a special functional power supply is used to simulate the size and change curve of the plasma induced current, and the current is applied to the inside of the film flow liquid metal in the experimental section through a direct connection mode of electrodes; through the specific insulation design of the liquid metal film flow experimental section and the circulating loop, the flow path of the current along the bottom wall channel and the circulating loop liquid metal fluid is insulated, so that the current is only applied to the inside of the film flow liquid metal in the experimental section. The application realizes the precise test of the influence of the plasma induced current on the MHD flow characteristics of the liquid metal film flow in a non-tokamak device, and has the advantages of being able to replace a complex tokamak device, high test efficiency and low test cost.

Description

Technical Field

[0001] This invention relates to the field of thermal flow testing technology for fusion reactors, and more specifically, to a testing device and method for the flow of liquid metal film magnetohydrodynamic fluid under the action of induced current. Background Technology

[0002] Compared to solid materials, liquid metal offers significant advantages as a plasma material for fusion reactors. For example, it can withstand extremely high surface heat loads and neutron fluxes, far exceeding those of traditional solid materials. Furthermore, the continuous flow and renewal of liquid metal avoids material damage caused by neutron irradiation. In addition, the fluidity of liquid metal gives it self-healing properties, enabling it to compensate for surface damage caused by plasma bombardment or thermal stress, thus extending the lifespan of the first wall. Therefore, liquid metal first walls hold promise for solving the problems of high heat flux and neutron irradiation damage associated with current solid materials, and are of great significance for the commercialization of fusion energy.

[0003] However, liquid metal as a plasma-facing material in fusion reactors faces significant scientific and technological challenges. As a plasma-facing material, liquid metal typically flows as a film stream on a solid bottom wall. Due to the strong magnetic field present in magnetically confined fusion reactors, the liquid metal film stream exhibits magnetohydrodynamic (MHD) effects, generating Lorentz drag, hindering the flow of liquid metal, and causing MHD instabilities. This can even lead to liquid metal sputtering into the plasma, affecting its operation. Furthermore, fluctuations in magnetic field strength occur during plasma operation, such as plasma start-up and shutdown processes, edge localized mode instabilities (ELMs), and large plasma disruption accidents. Rapid changes in the magnetic field within a short period can induce currents in the liquid metal of the first wall. The Lorentz force generated by the interaction of this induced current with the applied magnetic field may rise perpendicularly to the liquid surface, causing a large amount of liquid metal to be ejected into the plasma, triggering a plasma extinction accident. Therefore, studying the influence of plasma-induced currents on the MHD flow characteristics of liquid metal film streams is crucial for the safe operation of fusion reactors and is essential for the development of the liquid metal first wall.

[0004] Currently, research results on the influence of plasma-induced current on the flow characteristics of liquid metal film flow (MHD) are scarce, especially regarding the operating conditions of flowing liquid metal film flow, for which no relevant research reports have been found. The difficulty lies in the fact that while tokamaks can provide realistic magnetic field and induced current conditions, there are very few devices capable of conducting large-scale liquid metal film flow experiments within tokamaks. It is difficult to simulate realistic magnetic field and induced current conditions in non-tokamak laboratories. Furthermore, since both the liquid metal and the solid bottom wall are metals with high conductivity, it is difficult to directly apply current to the flowing liquid metal film flow; instead, most of the current is diverted through the channel bottom wall and the loop metal fluid. Therefore, achieving experimental research and quantitative testing of the influence of plasma-induced current on the MHD flow of liquid metal film flow in non-tokamak laboratories faces significant technical challenges. Summary of the Invention

[0005] The present invention aims to solve at least one of the aforementioned technical problems existing in the prior art.

[0006] Therefore, the first aspect of the present invention provides a test device for the flow of a liquid metal film magnetofluid under the action of an induced current.

[0007] A second aspect of the present invention provides a test method for the flow of a liquid metal film magnetofluid under the action of an induced current.

[0008] This invention provides a testing device for the flow of a liquid metal film magnetohydrodynamic fluid under the action of an induced current, comprising:

[0009] A functional power supply for simulating the induced current of a Carmack plasma, the functional power supply having a first electrode and a second electrode;

[0010] Superconducting magnets are used to simulate the circumferential magnetic field of a tokamak device;

[0011] The first storage tank is used to store liquid metal media;

[0012] The second storage tank is arranged above the first storage tank, and the first and second storage tanks are connected by a first pipeline; within the first pipeline, the liquid metal medium flows from the first storage tank to the second storage tank;

[0013] The membrane flow experimental structure is positioned below the second tank and above the first tank, and includes an inlet section, an experimental section, and an outlet section. The inlet section is electrically connected to a first electrode, and the outlet section is electrically connected to a second electrode. The inlet section is connected to the second tank via a first insulating pipe, and the outlet section is connected to the first tank via a second insulating pipe. The experimental section is located between the inlet section and the outlet section, and the experimental section is equipped with a conductive groove, which is insulated from both the inlet section and the outlet section.

[0014] In this process, after the liquid metal medium enters the membrane flow experimental structure from the inlet section, it forms a membrane flow in the conductive tank. Under the action of its own gravity, the membrane flow flows through the outlet section and into the first storage tank. The magnetic field direction of the superconducting magnet is perpendicular to the membrane flow direction.

[0015] The testing device for the flow of liquid metal film magnetohydrodynamic fluid under the action of induced current according to the above-described technical solution of the present invention may further have the following additional technical features:

[0016] In the above technical solution, the membrane flow experimental structure includes an insulating body; the insulating body is a groove-shaped structure; the insulating body is provided with a membrane flow inlet and a membrane flow outlet, the membrane flow inlet is connected to a first insulating pipe, and the membrane flow outlet is connected to a second insulating pipe;

[0017] One end of the insulating body is provided with a first connecting electrode to form an inlet section, and the first connecting electrode is conductively connected to the first electrode of the functional power supply.

[0018] The other end of the insulating body is provided with a second connecting electrode to form an outlet section, and the second connecting electrode is conductively connected to the second electrode of the functional power supply.

[0019] The conductive groove is arranged in the middle of the insulating body and is spaced apart from the first connecting electrode and the second connecting electrode, so that the conductive groove is insulated and isolated from the inlet section and the outlet section, respectively.

[0020] In the above technical solution, the conductive groove is detachably assembled to the insulating body.

[0021] In the above technical solution, the conductive groove is made of ferritic steel, martensitic steel or tungsten.

[0022] In the above technical solution, the insulating body is made of epoxy material.

[0023] In the above technical solution, the first connecting electrode includes a first conductive surface, a first conductive connector, and a first insulating gasket; the first conductive surface is disposed inside the insulating body and is used to receive the liquid metal medium flowing out of the membrane inlet; the first conductive connector is disposed outside the insulating body and is used to conductively connect with the first electrode of the functional power supply; the first insulating gasket is disposed between the first conductive connector and the first conductive surface, and the first conductive connector and the first conductive surface are fixed and conductively connected by bolts;

[0024] And / or, the second connecting electrode includes a second conductive surface, a second conductive connector, and a second insulating pad; the second conductive surface is disposed inside the insulating body for receiving the membrane flow out of the membrane experimental section; the second conductive connector is disposed outside the insulating body for conductive connection with the second electrode of the functional power supply; the second insulating pad is disposed between the second conductive connector and the second conductive surface, and the second conductive connector and the second conductive surface are fixed and conductively connected by bolts.

[0025] In the above technical solution, the membrane flow experimental structure also includes a rigid support structure, which is assembled on the outside of the insulating body to increase the structural strength of the membrane flow experimental structure.

[0026] In the above technical solution, the membrane inlet is a strip-shaped hole.

[0027] In the above technical solution, the first pipeline is an insulated pipeline, and the liquid metal medium flows from the first storage tank to the second storage tank through the pressure difference between the first storage tank and the second storage tank.

[0028] In the above technical solution, the first storage tank is equipped with a heating temperature control device, which is used to heat the temperature of the liquid metal medium in the first storage tank to the target temperature.

[0029] In the above technical solution, the liquid metal medium is selected as gallium indium tin eutectic alloy.

[0030] In the above technical solution, the first storage tank and / or the second storage tank are insulated from the ground and fixedly connected through a fixed assembly structure.

[0031] In the above technical solution, the fixed assembly structure includes:

[0032] Support lugs are fixedly connected to the tank body;

[0033] The support column is fixed to the ground at one end and connected to the support lug at the other end by a fixing bolt.

[0034] The third insulating gasket is placed on the contact surface between the fixing bolt and the support lug;

[0035] The fourth insulating pad is placed on the contact surface between the support ear and the support column.

[0036] In the above technical solution, the first pipeline is equipped with a first valve to control the opening and closing of the first pipeline;

[0037] And / or, the first insulating pipe is provided with a second valve to control the opening and closing of the first insulating pipe; the second insulating pipe is provided with a third valve to control the opening and closing of the second insulating pipe.

[0038] In the above technical solution, the testing device remains sealed within the flow range of the liquid metal medium.

[0039] In the above technical solution, the membrane flow experimental structure further includes:

[0040] A transparent observation window is provided to provide a viewing angle for observing the membrane flow within the experimental section.

[0041] The image acquisition device obtains image information of the flow state of the liquid metal film flow (MHD) in the experimental section through the transparent observation window.

[0042] This invention provides a method for testing the flow of a liquid metal film flow (MHD) under the influence of an induced current. The method employs the testing apparatus described in any of the above technical solutions to test the effect of the induced current on the flow of the liquid metal film flow (MHD). The testing method includes:

[0043] Disconnect the second insulating pipe and open the first pipe. Through the pressure difference between the first and second storage tanks, the liquid metal medium flows from the first storage tank to the second storage tank until the liquid metal medium level in the second storage tank reaches the preset value.

[0044] Balance the air pressure between the first and second storage tanks, open the first and second insulating pipes, and allow the liquid metal medium to flow from the second storage tank through the experimental section to form a stable film flow, and then flow back to the first storage tank; observe the film flow morphology in the experimental section using an image acquisition device;

[0045] Start the superconducting magnet and gradually increase the magnetic field strength to the target value; after the membrane flow stabilizes, start the functional power supply and apply a preset current waveform to the liquid metal medium in the experimental section; adjust the power supply parameters and monitor the current loop and voltage drop in the experimental section in real time to ensure that the current only forms a closed loop through the liquid metal membrane flow;

[0046] Record the flow pattern of liquid metal film flow in the experimental section, and simultaneously collect data on current, voltage, magnetic field strength, and liquid metal temperature. Generate time evolution curves based on the collected data.

[0047] Stop the application of current and magnetic field.

[0048] In the above technical solution, the experimental method also includes:

[0049] Repeat the experiment by changing the conductive tank to different materials, and compare the differences in MHD flow characteristics under conductive tanks of different materials.

[0050] In summary, due to the adoption of the above-mentioned technical features, the beneficial effects of the present invention are:

[0051] This invention provides a non-tokamak testing device that can simulate the plasma-induced current and strong magnetic field environment of a tokamak and directly apply the current to the liquid metal inside the membrane flow in the experimental section. This provides a technical solution and testing device for experimental research on the influence of plasma-induced current on the flow characteristics of liquid metal membrane flow (MHD).

[0052] Specifically, this invention utilizes a special functional power supply to accurately reproduce the amplitude and time evolution curve of plasma induced current in a tokamak. By adopting a direct electrode connection method, it achieves accurate testing of the influence of plasma induced current on the MHD flow characteristics of liquid metal film flow in non-tokamak devices. It has the advantages of being able to replace complex tokamak devices, having high testing efficiency, and low testing cost.

[0053] This invention uses air pressure and gravity to drive liquid flow, forming a stable and controllable liquid metal film flow, avoiding the current shunting problem caused by traditional pump drive; and adopts a specific insulation structure design for the experimental section to ensure that the current only acts on the liquid metal flowing in the experimental section, solving the problem of quantitative current loading in flowing liquid metal, making the experimental test results more reliable.

[0054] The modular insulation design of this invention (with replaceable conductive grooves and insulation structures) supports testing of conductive grooves made of different materials and has the advantages of strong scalability and wide testing range.

[0055] This invention utilizes a low-melting-point, low-corrosion gallium-indium-tin alloy and full-loop argon protection, enabling experiments to be safely conducted in conventional laboratories and significantly reducing research costs. This approach provides an efficient small-scale experimental platform for the study of the first wall of liquid metal in fusion reactors, possessing both engineering practicality and scientific value.

[0056] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0057] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0058] Figure 1 This is a schematic diagram of the structure of a test device for testing the flow of a liquid metal film magnetohydrodynamic fluid under the action of an induced current, according to an embodiment of the present invention.

[0059] Figure 2 This is a schematic diagram of the structure of the tank flange connection in a test device for testing the flow of liquid metal film magnetofluid under the action of induced current according to an embodiment of the present invention.

[0060] Figure 3This is a three-dimensional structural schematic diagram of the membrane flow experimental structure in a test device for testing liquid metal membrane flow magnetohydrodynamic flow under the action of induced current according to an embodiment of the present invention.

[0061] Figure 4 yes Figure 3 The front view of the experimental structure of the test device for testing liquid metal film flow magnetohydrodynamic flow under the action of induced current.

[0062] Figure 5 This is a schematic diagram of the fixed assembly structure in a test device for testing the flow of liquid metal film magnetohydrodynamic fluid under the action of induced current according to an embodiment of the present invention.

[0063] Figure 6 This is a schematic flowchart of a test method for testing the flow of a liquid metal film magnetohydrodynamic fluid under the action of an induced current, according to an embodiment of the present invention.

[0064] in, Figures 1 to 6 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0065] 1. First storage tank; 2. First pipeline; 3. Second storage tank; 4. First insulated pipeline; 5. Membrane flow experimental structure; 6. Second insulated pipeline; 7. Functional power supply; 8. Ground; 9. Superconducting magnet;

[0066] 11. Vacuum pressure tank body; 12. Fixed assembly structure; 13. Tank flange connection;

[0067] 121. Support column; 122. Fourth insulating gasket; 123. Third insulating gasket; 124. Fixing bolt; 125. Support lug;

[0068] 131. Temperature sensor; 132. Control valve; 133. Vacuum gas supply pipeline; 134. Pressure gauge;

[0069] 21. First valve;

[0070] 41. Second valve;

[0071] 51. Inlet section; 52. Experimental section; 53. Outlet section; 54. Insulating body; 55. First connecting electrode; 56. Second connecting electrode; 57. Rigid support structure;

[0072] 521. Conductive groove;

[0073] 541. Membrane inlet; 542. Membrane outlet;

[0074] 551. First conductive surface; 552. First conductive connector; 553. First insulating gasket; 554. First copper bolt;

[0075] 561. Second conductive surface; 562. Second conductive connector; 563. Second insulating gasket; 564. Second copper bolt. Detailed Implementation

[0076] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0077] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0078] The following reference Figures 1 to 6 This invention describes a test apparatus and method for testing the flow of a liquid metal film magnetohydrodynamic fluid under the action of an induced current, according to some embodiments of the present invention.

[0079] Some embodiments of this application provide a testing device for the flow of a liquid metal film magnetohydrodynamic fluid under the action of an induced current.

[0080] like Figure 1 As shown, the first embodiment of the present invention proposes a test device for the flow of liquid metal film magnetohydrodynamic fluid under the action of induced current, including: a functional power supply 7, a superconducting magnet 9, a first storage tank 1, a second storage tank 3, and a film flow experimental structure 5.

[0081] A functional power supply 7 is used to simulate the induced current of a Kamak plasma. The functional power supply 7 has a first electrode and a second electrode, which are the positive and negative terminals of the functional power supply 7, respectively. The specific configuration can be set as needed. A superconducting magnet 9 is used to simulate the circumferential strong magnetic field of a tokamak device. A first storage tank 1 is used to store a liquid metal medium; a second storage tank 3 is arranged above the first storage tank 1, and the first and second storage tanks 1 and 3 are connected by a first pipe 2; within the first pipe 2, the liquid metal medium flows from the first storage tank 1 to the second storage tank 3. The membrane flow experimental structure 5 is arranged at an incline, below the second tank 3 and above the first tank 1. It has an inlet section 51, an experimental section 52, and an outlet section 53. The inlet section 51 is electrically connected to the first electrode, and the outlet section 53 is electrically connected to the second electrode. The inlet section 51 is connected to the second tank 3 through a first insulating pipe 4, and the outlet section 53 is connected to the first tank 1 through a second insulating pipe 6. The experimental section 52 is arranged between the inlet section 51 and the outlet section 53. The experimental section 52 is provided with a conductive groove 521, which is insulated from both the inlet section 51 and the outlet section 53.

[0082] In this process, after the liquid metal medium enters the membrane flow experimental structure 5 from the inlet section 51, it forms a membrane flow in the conductive tank 521. Under the action of its own gravity, the membrane flow flows through the outlet section 53 and into the first storage tank 1. The magnetic field direction of the superconducting magnet 9 is perpendicular to the membrane flow direction. Specifically, the experimental section 52 is placed between the two magnetic poles of the superconducting magnet 9 so that the direction of the applied magnetic field is perpendicular to the membrane flow direction, and the maximum magnetic field strength can reach 4T.

[0083] In this embodiment, a split-type superconducting magnet 9 is used to simulate the circumferential strong magnetic field environment of a tokamak; a special functional power supply 7 is used to simulate the magnitude and variation curve of the plasma induced current, and the current is applied to the interior of the membrane flow liquid metal in the experimental section 52 through direct electrode connection; through the insulation design of the liquid metal membrane flow experimental section 52, the current is isolated from the flow path of the liquid metal fluid along the bottom wall channel and the circulation loop, so that the current is applied only to the interior of the membrane flow liquid metal in the experimental section 52.

[0084] In some embodiments, to completely eliminate the risk of electrical conductivity between the first tank 1 and the second tank 3, the first pipeline 2 is an insulated pipeline, and the liquid metal medium flows from the first tank 1 to the second tank 3 through the pressure difference between the first tank 1 and the second tank 3 within the first pipeline 2.

[0085] Specifically, the first storage tank 1 is used to store the experimental liquid metal medium, and the liquid metal in the first storage tank 1 can be forced into the second storage tank 3 using the pressure difference, so as to carry out subsequent membrane flow (MHD) experiments. Typically, the first storage tank 1 includes a vacuum pressure tank body 11 made of 316 stainless steel and a flange, with a copper gasket sealing the flange to the tank body. The flange connection 13 is as follows... Figure 2 As shown, a vacuum gas supply pipe 133 is connected above the flange. A control valve 132 is installed on the vacuum gas supply pipe 133 to perform vacuuming and gas supply operations on the tank. The supplied argon gas can protect the liquid metal from oxidation and also create a pressure difference between the two tanks, forcing the liquid metal into the second tank 3 through this pressure difference. A pressure gauge 134 is connected above the tank flange to monitor the pressure status inside the storage tank.

[0086] The second storage tank 3 is used to store the liquid metal medium pressurized into the first storage tank 1. Due to the height difference between the second tank 3, the membrane flow experimental structure 5, and the first storage tank 1, gravity allows the liquid metal medium to flow downwards through the experimental section 52, forming a liquid metal membrane flow, which finally flows into the first storage tank 1. The structure of the second storage tank 3 is the same as that of the first storage tank 1. The upper flange is also connected to a vacuum gas supply pipeline, control valve 132, and pressure gauge, etc., for the vacuuming and gas supply operations of the second storage tank 3.

[0087] In some embodiments, the liquid metal medium is selected from gallium indium tin eutectic alloy (GaInTT). 68 In 20 Sn 12 Gallium indium tin (GaInT) eutectic alloy has a melting point of only 10.7℃ and is characterized by stable chemical properties, low corrosiveness, and safety and environmental friendliness. Based on GaInT, membrane flow (MHD) experiments can be conducted at room temperature, greatly simplifying the experimental circuit design. Neither the circuit piping nor the experimental section 52 requires heating or insulation equipment. In one specific embodiment, to improve the fluidity of the GaInT, the fluid operating temperature is maintained at approximately 40℃ during the experiment. To achieve this operating temperature, the first storage tank 1 has a heating and temperature control device on its periphery. Electrical heating is used to first raise the temperature of the liquid metal medium inside the tank to the target temperature, which can be set to 40℃ or higher, before subsequent experimental tests begin.

[0088] The testing apparatus provided in this disclosure does not require a pump to provide loop circulation power. Instead, it uses air pressure to force liquid metal from the first tank 1 into the second tank 3. The liquid metal then flows through the experimental section 52 using gravity, utilizing the elevation difference between the first tank 1, the second tank 3, and the experimental section 52. Because no pump is used for circulation, the flow of liquid metal in this solution does not form a closed loop. Instead, it is disconnected by the first tank 1 and the second tank 3, which are connected by an insulated first pipe 2. This isolates the liquid metal in the first tank 1 from the electrical connection in the second tank 3, ultimately ensuring that the current can only form a closed loop through the liquid metal in the experimental section 52. If a pump were used to provide loop circulation power, the liquid metal would form a closed loop, causing the current to flow through the liquid metal outside the experimental section 52, creating a branch path. This would make it difficult to quantitatively measure the magnitude and time evolution curve of the current flowing through the liquid metal in the experimental section 52, posing a significant technical challenge to quantitative experimental measurements.

[0089] The membrane flow experimental structure 5 requires specific insulation design to prevent the applied current from being directly short-circuited through the conductive groove 521 of the experimental section 52 and thus unable to be applied to the interior of the flowing liquid metal.

[0090] In some embodiments, such as Figure 3As shown, the membrane flow experimental structure 5 includes an insulating body 54, for example, an insulating body 54 made of epoxy material; the insulating body 54 has a groove-shaped structure; the insulating body 54 is provided with a membrane flow inlet 541 and a membrane flow outlet 542, the membrane flow inlet 541 is connected to a first insulating pipe 4, and the membrane flow outlet 542 is connected to a second insulating pipe 6; a first connecting electrode 55 is arranged at one end of the insulating body 54 to form an inlet section 51, the first connecting electrode 55 is conductively connected to the first electrode of the functional power supply 7; a second connecting electrode 56 is arranged at the other end of the insulating body 54 to form an outlet section 53, the second connecting electrode 56 is conductively connected to the second electrode of the functional power supply 7; a conductive groove 521 is arranged in the middle of the insulating body 54, and is spaced apart from the first connecting electrode 55 and the second connecting electrode 56 respectively, so that the conductive groove 521 is insulated and isolated from the inlet section 51 and the outlet section 53 respectively.

[0091] In other words, the specific insulation design of the membrane flow experimental structure 5 involves using an insulating epoxy plate to isolate the positive and negative electrodes of the applied current. The positive electrode (first electrode) is connected to the inlet section 51 via the first connecting electrode 55, and the negative electrode (second electrode) is connected to the outlet section 53 via the second connecting electrode 56. The inlet section 51 and the outlet section 53 are designed separately, with the middle section transitioning through an epoxy plate flow channel. When the liquid metal flows from the inlet section 51 through the epoxy plate channel to the outlet section 53, the applied current can only form a closed loop through the liquid metal, thus achieving the function of applying current only to the interior of the liquid metal in the experimental section 52. The epoxy plate flow channel extends from the membrane flow inlet 541 to the membrane flow outlet 542. The conductive groove 521 covers part of the experimental area of ​​the epoxy plate flow channel that provides membrane flow. It can be understood that the conductive groove 521 achieves insulation isolation from the first connecting electrode 55 and the second connecting electrode 56 through the insulating body 54.

[0092] In some embodiments, such as Figure 4 As shown, the first connecting electrode 55 includes a first conductive surface 551, a first conductive connector 552, and a first insulating pad 553; the first conductive surface 551 is disposed inside the insulating body 54 and is used to receive the liquid metal medium flowing out of the membrane inlet 541; the first conductive connector 552 is disposed outside the insulating body 54 and is used to conductively connect with the first electrode of the functional power supply 7; the first insulating pad 553 is disposed between the first conductive connector 552 and the first conductive surface 551, and the first conductive connector 552 and the first conductive surface 551 are fixed and conductively connected by a first copper bolt 554;

[0093] The second connecting electrode 56 may adopt the same structure as the first connecting electrode 55, specifically including a second conductive surface 561, a second conductive connector 562, and a second insulating pad 563; the second conductive surface 561 is disposed inside the insulating body 54 and is used to receive the membrane flow out of the membrane experimental section 52; the second conductive connector 562 is disposed outside the insulating body 54 and is used to conductively connect with the second electrode of the functional power supply 7; the second insulating pad 563 is disposed between the second conductive connector 562 and the second conductive surface 561, and the second conductive connector 562 and the second conductive surface 561 are fixed and conductively connected by a second copper bolt 564.

[0094] It should be noted that in the above membrane flow experimental structure 5, except for the insulating body 54 and the copper connecting electrode, all other components can be made of 316 stainless steel.

[0095] In some embodiments, the membrane flow experimental structure 5 further includes a rigid support structure 57, which is assembled to the outside of the insulating body 54 to increase the structural strength of the membrane flow experimental structure 5. Figure 3 and Figure 4 In the illustrated embodiment, the rigid support mechanism is schematically represented as a channel made of 316 stainless steel, and is cooperatingly fixed on the insulating body 54 based on the assembly structure of the first connecting electrode 55 and the second connecting electrode 56. It can be understood that, at this time, the first insulating pad 553 and the second insulating pad 563 should be located between the conductive connector and the rigid support structure 57, and the copper bolts used for conduction and fixation should be insulated from the rigid support mechanism.

[0096] Based on the above configuration, it is ensured that the first electrode is only electrically connected to the first conductive surface 551, and the second electrode is only electrically connected to the second conductive surface 561. This further ensures that the applied current is reliably applied to the interior of the film-flow liquid metal in the experimental section 52.

[0097] In some embodiments, the conductive channel 521 is detachably assembled to the insulating body 54. That is, the experimenter can replace the conductive channel 521 as needed. The optional materials of the conductive channel 521 include ferritic steel, martensitic steel, and tungsten, etc., to study the influence of different material channels on the flow characteristics of MHD.

[0098] In some embodiments, the membrane flow inlet 541 is preferably strip-shaped and substantially the same width as the conductive groove 521 to improve the membrane flow effect.

[0099] In some embodiments, the first tank 1 and the second tank 3 are insulated from and fixedly connected to the ground 8 by the same fixed assembly structure 12. It is understood that the fixed assembly structures 12 of the first tank 1 and the second tank 3 may also be configured differently as needed.

[0100] In one specific embodiment, such as Figure 5 As shown, the fixed assembly structure 12 includes a support ear 125, a support column 121, a third insulating gasket 123, and a fourth insulating gasket 122. The support ear 125 is fixedly connected to the tank body; one end of the support column 121 is fixed to the ground 8, and the other end is connected to the support ear 125 by a fixing bolt 124; the third insulating gasket 123 is disposed on the contact surface between the fixing bolt 124 and the support ear 125; the fourth insulating gasket 122 is disposed on the contact surface between the support ear 125 and the support column 121. This prevents current from flowing into the ground through the conductive support structure. The height difference between the first tank 1 and the second tank 3 can be achieved by varying the height of the support columns 121. It is understood that the support column 121 corresponding to the relatively higher second tank 3 does not necessarily have to be fixed to the ground 8, but can also be fixed to other platforms with a certain height (above the ground 8).

[0101] In some embodiments, the first pipe 2 is provided with a first valve 21 to control the opening and closing of the first pipe 2; the first insulating pipe 4 is provided with a second valve 41 to control the opening and closing of the first insulating pipe 4; and the second insulating pipe 6 is provided with a third valve to control the opening and closing of the second insulating pipe 6. This facilitates experimental control and flow rate adjustment.

[0102] It is understood that the testing device remains sealed within the flow range of the liquid metal medium. That is, the entire experimental process needs to be carried out in a sealed environment, including but not limited to a sealed storage tank and membrane flow experimental structure 5.

[0103] In one specific embodiment, a transparent observation window is provided on the sealed membrane flow experimental structure 5 to form an observation view of the membrane flow within the experimental section 52; an image acquisition device is used to acquire image information of the liquid metal membrane flow (MHD) flow state within the experimental section 52 through the transparent observation window. The image acquisition device is typically a high-speed camera.

[0104] In one specific embodiment, the operation flow of the testing device is as follows:

[0105] The heating and temperature control device of the first storage tank 1 is activated. After the liquid metal reaches 40°C, the second valve 41 is closed and the first valve 21 is opened. The liquid metal medium is forced into the second storage tank 3 by adjusting the gas supply pressure of the first storage tank 1. When the liquid level reaches the preset value, the first valve 21 is closed. The gas pressure in the first storage tank 1 and the second storage tank 3 is balanced, and the second valve 41 is opened. The liquid metal is driven to form a stable film flow in the experimental section 52 by utilizing the height difference (e.g., 2 m). After the flow stabilizes, the superconducting magnet 9 is activated to apply a 2 T magnetic field. Subsequently, a current with an amplitude of 100 A is applied through the functional power supply 7. The start-up and descent time is 1 s, and the plateau time is 10 s.

[0106] A high-speed camera was used to record the flow state of the membrane flow (MHD) at 1000 frames / s, and current and voltage data of experimental section 52 were acquired simultaneously. The results showed that after the pulsed current was applied, the liquid metal in the membrane flow would eject upwards from the surface. The above experimental results verified the effectiveness of the epoxy insulation body 54 and the feasibility of the pumpless open circulation design, and also verified the effectiveness of applying current only to the flowing liquid metal membrane flow.

[0107] In another embodiment, to simulate the actual operating conditions of a fusion reactor, the replaceable conductive channel 521 is replaced with tungsten material, the channel wall thickness is 3 mm, and the surface is polished to Ra≤0.4μm. The magnetic field strength of the superconducting magnet 9 is increased to 4 T, and the liquid metal temperature is maintained at 40±2℃. The special function power supply 7 outputs current with an amplitude of 200 A and a frequency of 10 Hz to simulate the transient induced current of plasma. The first connecting electrode 55 and the second connecting electrode 56 are made of molybdenum-copper alloy material, and the temperature resistance is improved to 300℃.

[0108] After the liquid metal film flow is formed, a 4 T magnetic field is applied and an alternating current is started. Using a high-speed camera, the flow of the liquid metal film is observed to be hindered under the strong magnetic field, i.e., the film thickness increases, indicating liquid metal accumulation. When the alternating current is applied, the liquid metal exhibits intermittent ejection. By changing the output current amplitude of the special function power supply 7, a threshold current amplitude can be observed; ejection of liquid metal only occurs when the current amplitude exceeds this threshold, while unstable ripples appear on the film surface when the current amplitude is below this threshold.

[0109] Other embodiments of the present invention provide a test method for the flow of liquid metal film magnetohydrodynamic fluid under the action of induced current. The test device described in any of the above embodiments is used to test the effect of induced current on the flow of liquid metal film magnetohydrodynamic fluid (MHD). The test method includes at least the following steps S1-S5.

[0110] S1. Disconnect the second insulating pipe 6 and open the first pipe 2. Through the pressure difference between the first storage tank 1 and the second storage tank 3, the liquid metal medium flows from the first storage tank 1 to the second storage tank 3 until the liquid metal medium level in the second storage tank 3 reaches the preset value.

[0111] S2. Balance the air pressure between the first storage tank 1 and the second storage tank 3, open the first insulating pipe 4 and the second insulating pipe 6, so that the liquid metal medium flows from the second storage tank 3 through the experimental section 52 to form a stable film flow, and flows back to the first storage tank 1; observe the film flow morphology in the experimental section 52 through the image acquisition device;

[0112] S3. Start the superconducting magnet 9 and gradually increase the magnetic field strength to the target value; after the membrane flow stabilizes, start the functional power supply 7 and apply a preset current waveform to the liquid metal medium in the experimental section 52; adjust the power supply parameters and monitor the current loop and voltage drop in the experimental section 52 in real time to ensure that the current only forms a closed loop through the liquid metal membrane flow.

[0113] S4. Record the flow pattern of the liquid metal film flow in the experimental section 52, and simultaneously collect data on current, voltage, magnetic field strength, and liquid metal temperature. Generate a time evolution curve based on the collected data.

[0114] S5. Stop the current and magnetic field loading.

[0115] In one specific embodiment, the complete experimental method is as follows:

[0116] I. System Inspection and Vacuuming

[0117] Inspect the sealing of the first storage tank 1, the second storage tank 3, the connecting pipelines, and the experimental section 52, ensuring that the copper gaskets at the flange connections are intact and there is no risk of leakage. Verify the insulation performance of the insulated pipelines and support structures, confirming that the insulating gasket between the support lug 125 and the fixing nut is undamaged. Inspect the circuit connection status of the 96052 superconducting magnet 9 and the special function power supply 7, ensuring that the insulation structure between the electrodes and the experimental section 52 is intact.

[0118] Confirm that the liquid level of the gallium indium tin alloy in the first tank 1 does not exceed 80% of the tank height. Open the vacuum valves on the first tank 1 and the second tank 3, close other gas supply and pipeline valves, and use a vacuum pump to evacuate the first tank 1, the second tank 3 and the entire experimental system. After reaching the predetermined vacuum level, maintain it for a period of time to check the integrity of the vacuum seal of the system.

[0119] II. Membrane Flow Formation and Flow Regulation

[0120] The heating and temperature control device around the first storage tank 1 is activated to heat the liquid metal to 40°C, and the temperature is monitored in real time by the tank temperature sensor 131. After the liquid metal temperature stabilizes, the heating is maintained to ensure fluidity.

[0121] Close the valve (third valve) between the first storage tank 1 and the experimental section 52, and open the connecting valve (first valve 21) between the first storage tank 1 and the second storage tank 3. Adjust the pressure in the first storage tank 1 through the air supply valve to make the pressure inside the tank higher than that in the second storage tank 3, and use the pressure difference to force the liquid metal into the second storage tank 3. Monitor the liquid level in the second storage tank 3 through the liquid level sensor, and close the air supply and the first valve 21 after the preset value is reached.

[0122] Balance the air pressure between the first storage tank 1 and the second storage tank 3, open the second valve 41 and the third valve, allowing liquid metal to flow from the second storage tank 3 through the experimental section 52 to form a stable film flow, and finally flow back to the first storage tank 1. Observe the morphology of the liquid metal film flow in the experimental section 52 using a high-speed camera, and adjust the valve opening to control the flow rate to the target value.

[0123] III. Application of Magnetic Field and Electric Current

[0124] Start the superconducting magnet 9 and gradually increase the magnetic field strength to the target value (up to 4 T), with the magnetic field direction perpendicular to the membrane flow direction.

[0125] After the membrane flow stabilizes, the special function power supply 7 is activated to apply a preset current waveform (such as pulse current, alternating current, etc.) to the liquid metal medium in the experimental section 52.

[0126] Adjust the power supply parameters (current amplitude, frequency, duty cycle), monitor the current loop and voltage drop in experimental section 52 in real time, and ensure that the current only flows through the liquid metal film to form a closed loop.

[0127] IV. Data Collection and Analysis

[0128] A high-speed camera was used to record the flow morphology (such as surface ripples and droplet sputtering) of the liquid metal film flow in experimental section 52. Simultaneously, current, voltage, magnetic field strength, and liquid metal temperature data were collected, and time evolution curves were generated through the data acquisition system.

[0129] For different channel materials (such as tungsten or ferritic steel for conductive channel 521), repeated experiments were conducted to compare the differences in MHD flow characteristics.

[0130] V. Experiment Termination and System Maintenance

[0131] Gradually shut down the special function power supply 7 and the superconducting magnet 9, and stop the loading of current and magnetic field.

[0132] Close the second valve 41 and the third valve, and use gravity to drain the remaining liquid metal back to the first storage tank 1. Purge the experimental section 52 and pipelines with inert gas to remove any remaining liquid metal.

[0133] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0134] Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention shall be included within the scope of protection of this invention.

Claims

1. A testing device for the flow of a liquid metal film magnetohydrodynamic fluid under the action of an induced current, characterized in that, include: A functional power supply for simulating the induced current of a Carmack plasma, the functional power supply having a first electrode and a second electrode; Superconducting magnets are used to simulate the circumferential magnetic field of a tokamak device; The first storage tank is used to store liquid metal media; The second storage tank is arranged above the first storage tank, and the first and second storage tanks are connected by a first pipeline; within the first pipeline, the liquid metal medium flows from the first storage tank to the second storage tank; The membrane flow experimental structure is positioned below the second tank and above the first tank, and includes an inlet section, an experimental section, and an outlet section. The inlet section is electrically connected to a first electrode, and the outlet section is electrically connected to a second electrode. The inlet section is connected to the second tank via a first insulating pipe, and the outlet section is connected to the first tank via a second insulating pipe. The experimental section is located between the inlet section and the outlet section, and the experimental section is equipped with a conductive groove, which is insulated from both the inlet section and the outlet section. In this experiment, after the liquid metal medium enters the membrane flow experimental structure from the inlet section, it forms a membrane flow in the conductive tank. The membrane flow flows through the outlet section and into the first storage tank under its own gravity. The magnetic field direction of the superconducting magnet is perpendicular to the membrane flow direction. The first pipeline is an insulated pipeline. In the first pipeline, the liquid metal medium flows from the first storage tank to the second storage tank through the pressure difference between the first storage tank and the second storage tank. The first storage tank includes a vacuum pressure tank body and a flange that are sealed together. A vacuum gas supply pipeline is connected above the flange. The vacuum gas supply pipeline is equipped with a control valve for vacuuming and gas supplying the tank body.

2. The testing device for the magnetohydrodynamic flow of liquid metal film under the action of induced current according to claim 1, characterized in that, The membrane flow experimental structure includes an insulating body; the insulating body is a groove-shaped structure; the insulating body is provided with a membrane flow inlet and a membrane flow outlet, the membrane flow inlet is connected to a first insulating pipe, and the membrane flow outlet is connected to a second insulating pipe; One end of the insulating body is provided with a first connecting electrode to form an inlet section, and the first connecting electrode is conductively connected to the first electrode of the functional power supply. The other end of the insulating body is provided with a second connecting electrode to form an outlet section, and the second connecting electrode is conductively connected to the second electrode of the functional power supply. The conductive groove is arranged in the middle of the insulating body and is spaced apart from the first connecting electrode and the second connecting electrode, so that the conductive groove is insulated and isolated from the inlet section and the outlet section, respectively.

3. The testing device for the magnetohydrodynamic flow of liquid metal film under induced current according to claim 2, characterized in that, The conductive groove is detachably assembled to the insulating body.

4. The testing device for the magnetohydrodynamic flow of liquid metal film under induced current according to claim 3, characterized in that, The conductive groove is made of ferritic steel, martensitic steel, or tungsten.

5. The testing device for the magnetohydrodynamic flow of liquid metal film under the action of induced current according to claim 2, characterized in that, The insulating body is made of epoxy material.

6. The testing device for the magnetohydrodynamic flow of liquid metal film under induced current according to claim 2, characterized in that, The first connecting electrode includes a first conductive surface, a first conductive connector, and a first insulating gasket; the first conductive surface is disposed inside the insulating body and is used to receive the liquid metal medium flowing out of the membrane inlet; the first conductive connector is disposed outside the insulating body and is used to conductively connect with the first electrode of the functional power supply; the first insulating gasket is disposed between the first conductive connector and the first conductive surface, and the first conductive connector and the first conductive surface are fixed and conductively connected by bolts; And / or, the second connecting electrode includes a second conductive surface, a second conductive connector, and a second insulating pad; the second conductive surface is disposed inside the insulating body for receiving the membrane flow out of the membrane experimental section; the second conductive connector is disposed outside the insulating body for conductive connection with the second electrode of the functional power supply; the second insulating pad is disposed between the second conductive connector and the second conductive surface, and the second conductive connector and the second conductive surface are fixed and conductively connected by bolts.

7. The testing device for the magnetohydrodynamic flow of liquid metal film under induced current according to claim 2, characterized in that, The membrane flow experimental structure also includes a rigid support structure, which is assembled on the outside of the insulating body to increase the structural strength of the membrane flow experimental structure.

8. The testing device for the magnetohydrodynamic flow of liquid metal film under induced current according to claim 2, characterized in that, The membrane inlet is a strip-shaped hole.

9. The testing device for the magnetohydrodynamic flow of liquid metal film under induced current according to claim 1, characterized in that, The first storage tank is equipped with a heating and temperature control device, which is used to heat the temperature of the liquid metal medium in the first storage tank to the target temperature.

10. The testing device for the magnetohydrodynamic flow of liquid metal film under induced current according to claim 1, characterized in that, The liquid metal medium is selected from gallium indium tin eutectic alloy.

11. The testing device for the magnetohydrodynamic flow of liquid metal film under induced current according to claim 1, characterized in that, The first and / or second storage tanks are insulated from and fixedly connected to the ground via a fixed assembly structure.

12. The testing device for the magnetohydrodynamic flow of liquid metal film under induced current according to claim 11, characterized in that, The fixed assembly structure includes: Support lugs are fixedly connected to the tank body; The support column is fixed to the ground at one end and connected to the support lug at the other end by a fixing bolt. The third insulating gasket is placed on the contact surface between the fixing bolt and the support lug; The fourth insulating pad is placed on the contact surface between the support ear and the support column.

13. The testing device for the magnetohydrodynamic flow of liquid metal film under induced current according to claim 1, characterized in that, The first pipeline is equipped with a first valve to control the opening and closing of the first pipeline; And / or, the first insulating pipe is provided with a second valve to control the opening and closing of the first insulating pipe; the second insulating pipe is provided with a third valve to control the opening and closing of the second insulating pipe.

14. The testing device for magnetohydrodynamic flow of liquid metal film under induced current according to claim 1, characterized in that, The testing device remains sealed within the flow range of the liquid metal medium.

15. The testing device for the magnetohydrodynamic flow of liquid metal film under induced current according to claim 1, characterized in that, The membrane flow experimental structure also includes: A transparent observation window is provided to provide a viewing angle for observing the membrane flow within the experimental section. The image acquisition device obtains image information of the flow state of the liquid metal film flow (MHD) in the experimental section through the transparent observation window.

16. A method for testing the flow of a liquid metal film magnetohydrodynamic fluid under the action of an induced current, characterized in that, The effect of induced current on the flow of liquid metal film (MHD) is tested using the testing apparatus as described in any one of claims 1 to 15, wherein the testing method includes: Disconnect the second insulating pipe and open the first pipe. Through the pressure difference between the first and second storage tanks, the liquid metal medium flows from the first storage tank to the second storage tank until the liquid metal medium level in the second storage tank reaches the preset value. Balance the air pressure between the first and second storage tanks, open the first and second insulating pipes, and allow the liquid metal medium to flow from the second storage tank through the experimental section to form a stable film flow, and then flow back to the first storage tank; observe the film flow morphology in the experimental section using an image acquisition device; Start the superconducting magnet and gradually increase the magnetic field strength to the target value; after the membrane flow stabilizes, start the functional power supply and apply a preset current waveform to the liquid metal medium in the experimental section; adjust the power supply parameters and monitor the current loop and voltage drop in the experimental section in real time to ensure that the current only forms a closed loop through the liquid metal membrane flow; Record the flow pattern of liquid metal film flow in the experimental section, and simultaneously collect data on current, voltage, magnetic field strength, and liquid metal temperature. Generate time evolution curves based on the collected data. Stop the application of current and magnetic field.

17. The test method for the magnetohydrodynamic flow of liquid metal film under the action of induced current according to claim 16, characterized in that, Also includes: Repeat the experiment by changing the conductive tank to different materials, and compare the differences in MHD flow characteristics under conductive tanks of different materials.

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