A liquid metal mixed convection experimental system in a strong magnetic field environment

Abstract

The present invention discloses a liquid metal mixed convection experimental system in a strong magnetic field environment, belonging to the field of liquid metal experimental technology. The liquid metal mixed convection experimental system includes a working fluid circulation pipeline, and also includes an experimental section connected to the working fluid circulation pipeline; the experimental section includes an inlet section, a heating section and an outlet section connected in sequence; the inlet section is connected to one end of the working fluid circulation pipeline and is in a non-uniform magnetic field area; a honeycomb flow stabilizing tube is provided in the inlet section close to the heating section; the movement of liquid metal in the non-mainstream direction of the non-uniform magnetic field area is limited by the honeycomb flow stabilizing tube; the heating section is in a uniform magnetic field area, and a heating assembly is provided at the bottom of the heating section; the outlet section is connected to the other end of the working fluid circulation pipeline and is in a non-uniform magnetic field area; the outlet section is provided with an exhaust port and a drain port. The present invention adds a honeycomb flow stabilizing tube in the experimental section to avoid the influence of the non-uniform magnetic field on the liquid metal.

Description

Technical Field

[0001] The invention relates to the technical field of liquid metal experiments, and more specifically to a liquid metal mixed convection experimental system in a strong magnetic field environment. Background Art

[0002] Nuclear fusion has attracted much attention due to its high energy density, abundant reserves of raw materials and low cost, clean products, and safety and environmental protection. Countries regard nuclear fusion as an important part of the future energy structure and establish it as an important strategic development goal. Tokamak is the most likely nuclear fusion device to be commercialized, so it is of great significance to study tokamak. Based on the working principle of tokamak fusion, it can be seen that the blanket is one of the core components for the application of fusion energy, and it is also a functional carrier for fusion reactors to achieve application goals. It has the functions of realizing tritium multiplication, shielding radiation, and generating and taking away heat. At present, the blanket can be divided into two categories based on the material form of tritium breeder: solid blanket and liquid blanket. Comprehensive comparison shows that liquid blanket has the advantages of simple and safe structure, high efficiency, easy extraction of nuclear fuel, and high TBR.

[0003] The working environment of the blanket is extremely harsh, with strong magnetic fields, large heat sources and complex geometric configurations. The Hartmann number can reach 10 4 , the Grashof number can reach 10 9～10 , the Reynolds number can reach 10 5 In this environment, firstly, the liquid metal in the cladding produces magnetohydrodynamic effect due to the Lorentz force induced by the existence of the magnetic field; secondly, the liquid metal forms forced convection due to the pressure difference between the inlet and outlet on the one hand; on the other hand, natural convection is generated due to the buoyancy caused by the large temperature difference. Therefore, the final flow field will be in a very complex mixed convection state under the coupling of multiple mechanisms such as driving force, buoyancy, viscous force, electromagnetic force, etc., and will also produce some new abnormal, unique and complex flow and heat transfer behaviors.

[0004] The invention patent with application number 201410763709.7 provides a liquid metal medium forced convection experimental loop. This invention can create an experimental environment of fusion reactor working conditions outside the reactor according to the experimental purpose, and carry out experimental research on key technical issues of the blanket. However, due to the current limitations of superconducting technology, there is generally a part of non-uniform magnetic field area before and after the uniform magnetic field area, and the gradient of the change of the magnetic field intensity in this part is large. The non-uniform magnetic field area has a greater impact on the operation of the conductive fluid, which is equivalent to the conductor running in a changing magnetic field, generating an induced current, and the magnetic field will produce a force. However, it does not take into account the impact of the non-uniform magnetic field. Summary of the invention

[0005] In view of the above problems, the present invention provides a liquid metal mixed convection experimental system in a strong magnetic field environment, and adds a honeycomb flow stabilizing tube in the experimental section to avoid the influence of non-uniform magnetic field on liquid metal.

[0006] The purpose of the present invention is to provide a liquid metal mixed convection experimental system in a strong magnetic field environment, comprising a working fluid circulation pipeline and an experimental section connected to the working fluid circulation pipeline;

[0007] The experimental section includes an inlet section, a heating section and an outlet section which are connected in sequence;

[0008] The inlet section is connected to one end of the working medium circulation pipeline and is in a non-uniform magnetic field area; a honeycomb flow stabilizing tube is provided in the inlet section close to the heating section; the movement of the liquid metal in the non-mainstream direction of the non-uniform magnetic field area is limited by the honeycomb flow stabilizing tube;

[0009] The heating section is in a uniform magnetic field region, and a heating component is provided at the bottom of the heating section;

[0010] The outlet section is communicated with the other end of the working medium circulation pipeline and is in a non-uniform magnetic field area; the outlet section is provided with an exhaust port and a liquid discharge port.

[0011] The present invention arranges the honeycomb flow stabilizing tube in the inlet section close to the heating section. The reason for adding the honeycomb flow stabilizing tube with tiny channels in this section is that: since the cross-sectional size of each capillary in the honeycomb flow stabilizing tube is small, the movement of liquid metal in the non-mainstream direction in the non-uniform magnetic field area is restricted; and the intervals between the capillaries are very small, and the cross-sectional arrangement of the capillaries is very dense, so that the liquid metal has little convergence effect when it exits the capillary in the mainstream direction, thereby reducing the influence of the non-uniform magnetic field on the liquid metal.

[0012] In a preferred embodiment of the present invention, the honeycomb flow stabilizing tube includes an outer shell and a plurality of capillaries. The outer shell is in a tubular shape with openings at both ends, and the outer shell matches the inner cavity of the inlet section. The plurality of capillaries are sleeved in the outer shell and arranged in a honeycomb shape.

[0013] In a preferred embodiment of the present invention, an ultrasonic Doppler velocity measuring probe and a temperature monitoring component are detachably connected to the heating section.

[0014] In a preferred embodiment of the present invention, the heating section is provided with a plurality of slots and a plurality of velocity probe interfaces, and the heating section is detachably connected to the temperature monitoring component through the slots; the heating section is detachably connected to the ultrasonic Doppler velocity probe through the velocity probe interface. During the experiment, the ultrasonic Doppler velocity probe is inserted into the velocity probe interface at different positions according to the experimental requirements. Similarly, the slot is used to connect the temperature monitoring component, and the temperature information is obtained through the temperature monitoring component to obtain the change of heat transfer strength.

[0015] In a preferred embodiment of the present invention, a hose is sleeved on the speed probe interface, and the ultrasonic Doppler speed probe penetrates the hose and the speed probe interface and is inserted into the heating section. When the hose is sleeved, it is assembled using a temperature difference assembly method, and it is understandable that this part needs to meet the sealing requirements.

[0016] In a preferred embodiment of the present invention, the inlet end of the inlet section and the outlet end of the outlet section are both provided with valves; when cleaning the ultrasonic Doppler velocity measuring probe, the liquid metal is prevented from being ejected by closing the valves. Then, the oxide on the surface of the ultrasonic Doppler velocity measuring probe is cleaned with alcohol.

[0017] In a preferred embodiment of the present invention, the heating components are arranged in an S-shape along the flow direction of the liquid metal. This arrangement method is conducive to achieving uniform heating.

[0018] In a preferred embodiment of the present invention, a square groove is provided on the bottom of the heating section, the heating assembly is arranged in the square groove, the heating assembly comprises a heating wire and a glass fiber tube, and the glass fiber tube is sleeved on the heating wire. The glass fiber tube serves as a sleeve and has an insulating effect. The glass fiber tube is sleeved on the heating wire to separate the heating wire and the pipeline of the experimental section.

[0019] In a preferred embodiment of the present invention, pressure differential gauge interfaces are provided at both ends of the heating section, and a pressure differential gauge is connected through the pressure differential gauge interface to monitor and record the pressure difference at both ends of the heating section.

[0020] In a preferred embodiment of the present invention, the working medium circulation pipeline is provided with a liquid storage tank, an electromagnetic pump, a heat exchanger, a flow meter, an expansion tank, a superconducting magnet, an argon tank, a vacuum pump and a buffer tank; the liquid storage tank is used to store liquid metal in an argon environment;

[0021] The liquid metal mixed convection experimental system under a strong magnetic field environment comprises a gas circuit and a liquid circuit;

[0022] The liquid path is that the liquid metal passes through the buffer tank, the electromagnetic pump, the heat exchanger, the flow meter, the expansion tank, the inlet section, the heating section and the outlet section in sequence, and the inlet section, the heating section and the outlet section are all provided with the superconducting magnets. The liquid metal is processed under the action of the superconducting magnets, and then flows out from the outlet section and enters the buffer tank to form a loop;

[0023] The gas circuit provides argon atmosphere to the expansion tank, the buffer tank and the liquid storage tank through the argon tank.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention adds a honeycomb flow-stabilizing tube at the entrance of the experimental section. Since the cross-sectional size of each capillary in the honeycomb flow-stabilizing tube is small, the movement of liquid metal in the non-mainstream direction in the non-uniform magnetic field area is limited. In addition, the intervals between the capillaries are very small, and the cross-sectional arrangement of the capillaries is very dense, so that the liquid metal has a small convergence effect when it exits the capillary in the mainstream direction. This avoids the influence of the non-uniform magnetic field on the liquid metal.

[0026] In addition, the present invention also provides valves on the inlet section and the outlet section. The valves are used to partition the ultrasonic Doppler velocity measuring probe so that liquid metal will not be sprayed out due to the liquid level difference when cleaning the ultrasonic Doppler velocity measuring probe. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic structural diagram of a liquid metal mixed convection experimental system in a strong magnetic field environment provided by the present invention.

[0028] Figure 2 A schematic diagram of the structure of the experimental section provided by the present invention.

[0029] Figure 3 This is a schematic structural diagram of the heating section provided by the present invention.

[0030] Figure 4 Schematic diagram of the structure of the honeycomb pipe.

[0031] Figure 5 It is the temperature distribution diagram of the bottom surface of the heating surface along the flow direction.

[0032] Figure 6 It is the temperature distribution diagram of the bottom surface of the heating surface perpendicular to the flow direction.

[0033] Figure numerals: 1-liquid storage tank, 2-electromagnetic pump, 3-heat exchanger, 4-flow meter, 5-expansion tank, 6-experimental section, 61-inlet section, 611-ball valve for experimental section, 612-housing, 613-capillary, 62-heating section, 621-heating surface, 622-slot, 623-speed probe interface, 624-hose, 625-differential pressure gauge interface, 63-outlet section, 631-exhaust port, 632-drain port, 7-superconducting magnet, 8-argon Gas tank, 9-vacuum pump, 10-buffer tank, EV1-first solenoid valve, EV2-second solenoid valve, V1-first ball valve, V2-second ball valve, V3-third ball valve, V4-fourth ball valve, V5-fifth ball valve, V6-sixth ball valve, V7-seventh ball valve, V8-eighth ball valve, V9-ninth ball valve, P1-first pressure gauge, P2-second pressure gauge, P3-third pressure gauge, L1-first liquid level gauge, L2-second liquid level gauge, B-magnetic field. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Example 1

[0036] A liquid metal mixed convection experimental system in a strong magnetic field environment includes a working fluid circulation pipeline, such as Figure 1 As shown, it also includes an experimental section 6 connected to the working fluid circulation pipeline.

[0037] like Figure 2-Figure 4 As shown, the experimental section 6 includes an inlet section 61, a heating section 62 and an outlet section 63 which are connected in sequence, the inlet section 61 and the outlet section 63 are in a non-uniform magnetic field area, the heating section 62 is in a uniform magnetic field area, and a heating component is provided at the bottom of the heating section 62.

[0038] The inlet section 61 is connected to one end of the working medium circulation pipeline; a honeycomb flow stabilizing tube is provided in the inlet section 61 close to the heating section 62; the movement of liquid metal in the non-mainstream direction of the non-uniform magnetic field region is limited by the honeycomb flow stabilizing tube.

[0039] A heating component is disposed at the bottom of the heating section 62 .

[0040] The outlet section 63 is communicated with the other end of the working medium circulation pipeline; the outlet section 63 is provided with an exhaust port 631 and a liquid discharge port 632 .

[0041] Further, such as Figure 4 As shown, the honeycomb flow stabilizing tube includes an outer shell 612 and a plurality of capillaries 613. The outer shell 612 is in a tubular shape with openings at both ends. The outer shell 612 matches the inner cavity of the inlet section 61. The plurality of capillaries 613 are sleeved in the outer shell 612 and arranged in a honeycomb shape.

[0042] The inlet section 61 is a non-uniform magnetic field section, which is provided to ensure that the fluid entering the heating section 62 is fully developed. Liquid metal will generate electromagnetic force in the changing magnetic field B, affecting the fluid. Therefore, a honeycomb flow stabilizer is provided in the inlet section 61 close to the heating section 62. The reason for adding the honeycomb flow stabilizer with tiny channels in this section is that the cross-sectional size of each capillary 613 in the honeycomb flow stabilizer is small, which limits the movement of liquid metal in the non-mainstream direction in the non-uniform magnetic field area. Moreover, the intervals between the capillaries 613 are very small, and the cross-sectional arrangement of the capillaries 613 is very dense, so that the convergence effect of the liquid metal in the mainstream direction when the liquid metal flows out of the capillaries 613 is small, thereby reducing the influence of the non-uniform magnetic field on the liquid metal; the exhaust port 631 is set to ensure that there are no bubbles in the pipeline; the drain port 632 is more inclined to the vertical plane. Since liquid metal is expensive, the liquid metal needs to be collected after each experiment. In order to ensure that the liquid metal in the experimental section 6 is fully discharged, the drain port 632 can be connected to the liquid storage tank 1 by tilting the pipeline.

[0043] Ultrasonic Doppler velocity measurement is rarely used in pipeline convection experiments of liquid metal. The main reason is that liquid metal is easy to oxidize, especially in a high temperature environment, which will accelerate its oxidation rate. Most of the oxidation often floats on the upper part of the fluid. The ultrasonic Doppler velocity measurement probe is often installed on the pipeline and is easily affected by the oxide of the liquid metal. In order to solve this problem, the present invention further provides that the ultrasonic Doppler velocity measurement probe and the temperature monitoring component are detachably connected to the heating section 62; and a plurality of slots 622 and a plurality of velocity measurement probe interfaces 623 are provided on the heating section 62. The heating section 62 is detachably connected to the temperature monitoring component through the slots 622; and the heating section 62 is detachably connected to the ultrasonic Doppler velocity measurement probe through the velocity measurement probe interface 623. During the experiment, except for the slots 622 and the velocity measurement probe interface 623 used, the other slots 622 are sealed.

[0044] It can be understood that the measurement technologies for immersed liquid metal include potential probes, hot wire anemometers, thermocouples, etc., and the slot 622 with many custom modules arranged along the way provides a variable design for different experiments or different needs; a temperature monitoring component is inserted into the slot 622, and the temperature information obtained by the temperature monitoring component can obtain the change in heat transfer intensity.

[0045] Preferably, a hose 624 is sleeved on the speed measuring probe interface 623 , and the ultrasonic Doppler speed measuring probe passes through the hose 624 and the speed measuring probe interface 623 and is inserted into the heating section 62 .

[0046] It should be noted that the outer diameter of the velocity probe interface 623 is larger than the inner diameter of the hose 624, and the connection is made by interference fitting. Specifically, the present invention adopts a temperature difference fitting method, utilizing the thermal expansion and contraction of the hose 624. After heating one end of the hose 624, the inner diameter of the hose 624 becomes larger, so that the hose 624 is sleeved on the velocity probe interface 623. It should be noted that the inner diameter of the hose 624 is the same as the outer diameter of the ultrasonic Doppler velocity probe, in order to achieve the sealing requirement. The inner diameter of the velocity probe interface 623 is the same as the outer diameter of the ultrasonic Doppler velocity probe.

[0047] Specifically, when cleaning the oxide on the surface of the ultrasonic Doppler velocity measuring probe, the ultrasonic Doppler velocity measuring probe is taken out from the velocity measuring probe interface 623 and cleaned and wiped with alcohol. Specifically, alcohol wipes can be used. However, due to the liquid level difference, liquid metal will be ejected when the ultrasonic Doppler velocity probe is taken out. Therefore, the present invention creatively arranges valves at the inlet end of the inlet section 61 and the outlet end of the outlet section 63. Specifically, the valve is a ball valve 611 for the experimental section. The function of the ball valve 611 for the experimental section is to replace the slot 622 and the ultrasonic Doppler velocity probe. During actual use, the experimental section 6 is often placed in a low-level area. In order to ensure that there are no bubbles in the experimental section 6, due to the liquid level difference, when the slot 622 or the ultrasonic Doppler velocity probe is pulled out, the liquid metal in the pipeline will be ejected. When the ball valve is closed, there will be no liquid level difference between the experimental section 6 and other parts of the loop. When the ultrasonic Doppler velocity probe is cleaned, the ball valve 611 for the experimental section is closed, that is, the ultrasonic Doppler velocity probe is taken out through the partition of the ball valve 611 for the experimental section, and there will be no liquid level difference, thereby avoiding liquid metal ejection. Specifically, before closing the ball valve 611 for the experimental section, the pump is stopped, and the liquid metal does not flow when the ultrasonic Doppler velocity measuring probe is cleaned.

[0048] Furthermore, in the prior art, the mixed convection experiment is that liquid metal flows through a pipe, one side of the pipe is heated, and the other sides are insulated. In conventional experiments, thermal insulation cotton is usually added. At this time, there is not only forced convection, but also natural convection, which is also commonly known as a mixed convection experiment. In the experiment, the conductivity of the four walls must be consistent. This is because if the conductivity is inconsistent, the experiment does not control a single variable, which affects the experimental results. Therefore, the wall material is usually stainless steel, and the thermal conductivity of stainless steel is relatively poor among metals. Therefore, how to pass heat through stainless steel and introduce it into liquid metal is a problem that needs to be solved in the current mixed convection experiment of conductive walls. Conductive walls generally refer to metal walls.

[0049] The inventor found that the current method is mainly to attach the heating plate to the heating surface, but the processing error of the heating plate and the processing error of the experimental section pipe make the two not fit perfectly, and there is a gap, and the thermal conductivity of air is low. Based on this, the present invention further sets a heating surface 621 on the heating section 62. Specifically, a square groove is provided at the bottom of the heating section 62, and the heating component is buried in the square groove to form the heating surface 621. Then, a material plate with low thermal conductivity is covered on the heating component to achieve the effect of support and insulation. The material plate with low thermal conductivity is such as an electrical board.

[0050] Preferably, the heating assembly used in the present invention includes a heating wire and a glass fiber tube, and the glass fiber tube is sleeved on the heating wire; this is because the glass fiber tube is sleeved on the heating wire, and the glass fiber tube serves as a sleeve and has an insulating effect. The glass fiber tube is sleeved on the heating wire to separate the heating wire and the heating section 62.

[0051] Furthermore, the present invention also selects the most uniform heating method through simulation software, and the heating wire is selected as chromium-nickel alloy wire, that is, the heating component is the glass fiber tube sleeved on the chromium-nickel alloy wire, and the heating component is arranged in an S shape along the flow direction of the liquid metal.

[0052] A differential pressure gauge interface 625 is provided at both ends of the heating section 62. A differential pressure gauge is connected through the differential pressure gauge interface 625 to monitor and record the pressure difference at both ends of the heating section 62. By monitoring the pressure difference between the inlet and outlet of the heating section 62, the influence of the magnetic field B on the pipeline pressure drop is further analyzed. Generally, the pressure difference is 0Pa.

[0053] It can be understood that the working medium circulation pipeline is provided with the liquid storage tank 1, the electromagnetic pump 2, the heat exchanger 3, the flow meter 4, the expansion tank 5, the superconducting magnet 7, the argon tank 8, the vacuum pump 9 and the buffer tank 10. Figure 1 shown.

[0054] The liquid metal mixed convection experimental system in a strong magnetic field environment provided by the present invention comprises a gas circuit and a liquid circuit;

[0055] (1) The liquid circuit is a liquid metal that passes through the buffer tank 10, the electromagnetic pump 2, the heat exchanger 3, the flow meter 4, the expansion tank 5, the inlet section 61, the heating section 62 and the outlet section 63 in sequence. The inlet section 61, the heating section 62 and the outlet section 63 are all provided with the superconducting magnet 7. The liquid metal is processed under the action of the superconducting magnet 7, and then flows out of the outlet section 63 and enters the buffer tank 10 to form a loop.

[0056] In order to store liquid metal in an argon environment, the present invention further provides the liquid storage tank 1, which is arranged between the buffer tank 10 and the electromagnetic pump 2 and is connected to the working fluid circulation pipeline through a first branch pipeline.

[0057] It should be noted that valves are provided between the liquid storage tank 1, the electromagnetic pump 2, the heat exchanger 3, the flow meter 4, the expansion tank 5, the superconducting magnet 7, the argon tank 8, the vacuum pump 9, and the buffer tank 10. The valves used in the present invention are ball valves and electromagnetic valves. Specifically, the valves are provided as follows: Figure 1 shown.

[0058] A first ball valve V1 is provided between the buffer tank 10 and the electromagnetic pump 2, a second ball valve V2 is provided on the first branch pipeline, the expansion tank 5 is arranged between the flow meter 4 and the experimental section 6, and is connected to the working fluid circulation pipeline through the second branch pipeline, a ninth ball valve V9 is provided on the second branch pipeline, a second electromagnetic valve EV2 is provided between the flow meter 4 and the experimental section 6, the second electromagnetic valve EV2 is on the right side of the expansion tank 5, and a first electromagnetic valve EV1 is provided between the experimental section 6 and the buffer tank 10.

[0059] (2) The gas circuit provides argon atmosphere to the expansion tank 5 , the buffer tank 10 , and the liquid storage tank 1 through the argon tank 8 .

[0060] An eighth ball valve V8 is provided between the argon tank 8 and the expansion tank 5 , a sixth ball valve V6 is provided between the argon tank 8 and the buffer tank 10 , and a fourth ball valve V4 is provided between the argon tank 8 and the liquid storage tank 1 .

[0061] The vacuum pump 9 is used to discharge air from the expansion tank 5 , the buffer tank 10 , and the liquid storage tank 1 .

[0062] A seventh ball valve V7 is provided between the vacuum pump 9 and the expansion tank 5 , a fifth ball valve V5 is provided between the vacuum pump 9 and the buffer tank 10 , and a third ball valve V3 is provided between the vacuum pump 9 and the liquid storage tank 1 .

[0063] The electromagnetic pump 2 is used to drive the flow of liquid metal and provide a specific flow rate; the heat exchanger 3 is set to ensure that the temperature of the liquid metal entering the pipeline is constant each time; the flow meter 4 is used to measure the flow in the loop system; the expansion tank 5 ensures that the experimental section 6 is full of liquid metal; the superconducting magnet 7 is used to provide a uniform magnetic field device; the vacuum pump 9 is used to extract gas from the system; the buffer tank 10 has a buffering effect on the liquid metal after being heated by the experimental section 6.

[0064] The liquid metal mixed convection experimental system in a strong magnetic field environment provided by the present invention has the following steps of use:

[0065] Step 1: Check air tightness

[0066] Step 1.1, open the first electromagnetic valve EV1, the second electromagnetic valve EV2, the first ball valve V1, the eighth ball valve V8 and the ninth ball valve V9, open the argon tank 8, and pass argon into the circuit. When the third pressure gauge P3 reaches above 20KPa, close the eighth ball valve V8 and observe the value of the third pressure gauge P3. Specifically, the value of the third pressure gauge P3 is selected according to the maximum pressure value that the entire circuit can withstand.

[0067] Step 1.2: If the eighth ball valve V8 is closed and the value of the third pressure gauge P3 does not change within one hour, it indicates that the air tightness of the circuit is good. Otherwise, spray the pipe connection with bubble water, check and deal with the leak, and then repeat steps 1.1 and 1.2.

[0068] Step 2: Exhaust air

[0069] Step 2.1, open the first electromagnetic valve EV1, the second electromagnetic valve EV2, the first ball valve V1, the sixth ball valve V6 and the ninth ball valve V9. Open the argon tank 8, and when the third pressure gauge P3 reaches above 10KPa, close the sixth ball valve V6 and the argon tank 8.

[0070] Step 2.2: While the first electromagnetic valve EV1, the second electromagnetic valve EV2, the first ball valve V1 and the ninth ball valve V9 are kept in an open state, the seventh ball valve V7 is opened. The vacuum pump 9 is turned on, and when the third pressure gauge P3 reaches below -10 KPa, the seventh ball valve V7 and the vacuum pump 9 are closed.

[0071] Step 2.3: Repeat steps 2.1 and 2.2 3 to 5 times to fully exhaust the air in the circuit.

[0072] In step 2, when the air is exhausted, the flow rate does not change under the same pump driving power when the operation exceeds 3 hours. At this time, it is determined that the purpose of fully exhausting the air in the circuit has been achieved.

[0073] Step 3: Fill the liquid metal

[0074] Step 3.1, open the first electromagnetic valve EV1, the second electromagnetic valve EV2, the first ball valve V1, the seventh ball valve V7 and the ninth ball valve V9. Open the vacuum pump 9, and when the third pressure gauge P3 reaches below -30 KPa, close the seventh ball valve V7 and the vacuum pump 9.

[0075] Step 3.2, open the fourth ball valve V4, open the argon tank 8, and when the first pressure gauge P1 reaches above 100 KPa, close the sixth ball valve V6 and the argon tank 8.

[0076] Step 3.3, slowly open the second ball valve V2, and after the first pressure gauge P1, the second pressure gauge P2 and the third pressure gauge P3 are stable, close the second ball valve V2.

[0077] If the second liquid level gauge L2 shows that the liquid metal in the tank of the expansion tank 5 occupies half of the vertical height of the expansion tank 5 , this step is completed; otherwise, step 3 is repeated.

[0078] Step 4: Equipment operation

[0079] Step 4.1: Open the first electromagnetic valve EV1, the second electromagnetic valve EV2, the first ball valve V1 and the seventh ball valve V7, operate the electromagnetic pump 2, and observe the reading of the flow meter 4 and the value of the second liquid level meter L2. In this step, the liquid metal flows from the liquid storage tank 1 to the expansion tank 5.

[0080] If the reading of the flow meter 4 is stable, and the second liquid level meter L2 shows that the liquid metal in the tank of the expansion tank 5 occupies half of the vertical height of the expansion tank 5, the device can continue to operate. Otherwise, repeat step 3.

[0081] Step 5: Shutdown

[0082] Step 5.1, open the first electromagnetic valve EV1, the second electromagnetic valve EV2, the first ball valve V1 and the third ball valve V3. Turn on the vacuum pump 9, and when the first pressure gauge P1 reaches below -30 KPa, close the third ball valve V3 and the vacuum pump 9.

[0083] Step 5.2, slowly open the second ball valve V2, and after the first pressure gauge P1 and the first liquid level gauge L1 are stable, repeat the operation in step 5.1. When the first pressure gauge P1 is continuously lowered by the vacuum pump 9 and the first liquid level gauge L1 is stable, shut down other equipment and complete the shutdown operation.

[0084] Through the simulation software, the heat flux density is set to 10w / cm 2 The flow rate is 100 mm / s, and then a simulation test is performed to ensure the rationality of the heating method designed by the present invention. Figure 5 and Figure 6 .

[0085] Figure 5 It is a temperature distribution diagram along the flow direction. The uniformity of heat conduction can be seen from the temperature distribution on the bottom surface of the heating surface 621.

[0086] Figure 6 It is a temperature distribution diagram perpendicular to the flow direction. The uniformity of heat conduction can be seen from the temperature distribution on the bottom of the heating surface 621.

[0087] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0088] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations 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 variations.

Claims

1. A liquid metal mixed convection experimental system in a strong magnetic field environment, comprising a working fluid circulation pipeline, characterized in that: It also includes an experimental section (6) connected to a working fluid circulation pipeline; The experimental section (6) comprises an inlet section (61), a heating section (62) and an outlet section (63) which are connected in sequence; The inlet section (61) is connected to one end of the working fluid circulation pipeline and is in a non-uniform magnetic field area; a honeycomb flow stabilizing tube is provided in the inlet section (61) close to the heating section (62); the movement of liquid metal in a non-mainstream direction in the non-uniform magnetic field area is restricted by the honeycomb flow stabilizing tube; the honeycomb flow stabilizing tube comprises an outer shell (612) and a plurality of capillaries (613); the outer shell (612) is in the shape of a tube with two ends open, the outer shell (612) matches the inner cavity of the inlet section (61), and the plurality of capillaries (613) are sleeved in the outer shell (612) and arranged in a honeycomb shape; The heating section (62) is located in a uniform magnetic field region, and a heating component is provided at the bottom of the heating section (62); The outlet section (63) is in communication with the other end of the working medium circulation pipeline and is located in a non-uniform magnetic field region; the outlet section (63) is provided with an exhaust port (631) and a liquid discharge port (632); The working fluid circulation pipeline is provided with a liquid storage tank (1), an electromagnetic pump (2), a heat exchanger (3), a flow meter (4), an expansion tank (5), a superconducting magnet (7), an argon tank (8), a vacuum pump (9) and a buffer tank (10); the liquid storage tank (1) is used for storing liquid metal in an argon environment; The liquid metal mixed convection experimental system under a strong magnetic field environment comprises a gas circuit and a liquid circuit; The liquid circuit is a circuit in which the liquid metal passes through the buffer tank (10), the electromagnetic pump (2), the heat exchanger (3), the flow meter (4), the expansion tank (5), the inlet section (61), the heating section (62) and the outlet section (63) in sequence. The inlet section (61), the heating section (62) and the outlet section (63) are all provided with the superconducting magnet (7). The liquid metal is processed under the action of the superconducting magnet (7) and then flows out of the outlet section (63) to enter the buffer tank (10) to form a loop. The gas circuit provides argon gas atmosphere to the expansion tank (5), the buffer tank (10) and the liquid storage tank (1) through the argon gas tank (8).

2. The liquid metal mixed convection experimental system in a strong magnetic field environment according to claim 1, characterized in that: The heating section (62) is detachably connected with an ultrasonic Doppler velocity measuring probe and a temperature monitoring component.

3. The liquid metal mixed convection experimental system in a strong magnetic field environment according to claim 2, characterized in that: The heating section (62) is provided with a plurality of slots (622) and a plurality of velocity probe interfaces (623); the heating section (62) is detachably connected to the temperature monitoring component via the slots (622); and the heating section (62) is detachably connected to the ultrasonic Doppler velocity probe via the velocity probe interface (623).

4. The liquid metal mixed convection experimental system in a strong magnetic field environment according to claim 3, characterized in that: A hose (624) is sleeved on the speed measuring probe interface (623), and the ultrasonic Doppler speed measuring probe passes through the hose (624) and the speed measuring probe interface (623) and is inserted into the heating section (62).

5. The liquid metal mixed convection experimental system in a strong magnetic field environment according to claim 3, characterized in that: The inlet end of the inlet section (61) and the outlet end of the outlet section (63) are both provided with valves; when cleaning the ultrasonic Doppler velocity measuring probe, the valves are closed to prevent the liquid metal from being ejected.

6. The liquid metal mixed convection experimental system in a strong magnetic field environment according to claim 1, characterized in that: The heating components are arranged in an S shape along the flow direction of the liquid metal.

7. The liquid metal mixed convection experimental system in a strong magnetic field environment according to claim 6, characterized in that: The bottom of the heating section (62) is provided with a square groove, the heating component is arranged in the square groove, the heating component comprises a heating wire and a glass fiber tube, and the glass fiber tube is sleeved on the heating wire.

8. The liquid metal mixed convection experimental system in a strong magnetic field environment according to claim 1, characterized in that: A differential pressure gauge interface (625) is provided at both ends of the heating section (62), and a differential pressure gauge is connected through the differential pressure gauge interface (625) to monitor and record the pressure difference at both ends of the heating section.

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