Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present application. It will be apparent that the described embodiments are one embodiment, but not all embodiments, of the present application. All other embodiments, which can be made by a person skilled in the art without creative efforts, based on the described embodiments of the present application fall within the protection scope of the present application.
It is to be noted that unless otherwise defined, technical or scientific terms used herein should be taken in a general sense as understood by one of ordinary skill in the art to which the present application belongs. If, throughout, reference is made to "first," "second," etc., the description of "first," "second," etc., is used merely for distinguishing between similar objects and not for understanding as indicating or implying a relative importance, order, or implicitly indicating the number of technical features indicated, it being understood that the data of "first," "second," etc., may be interchanged where appropriate. If "and/or" is present throughout, it is meant to include three side-by-side schemes, for example, "A and/or B" including the A scheme, or the B scheme, or the scheme where A and B are satisfied simultaneously.
An embodiment of the present application provides a liquid metal electromagnetic pump, referring to fig. 1, including a pipe portion 10 provided with an inlet 101 for receiving inflow of liquid metal and an outlet 102 for delivering the liquid metal to the outside, a coil portion 20 provided on the radial outside of the pipe portion 10, the coil portion 20 being capable of generating a magnetic field inside the pipe portion 10 to drive the liquid metal to flow in the pipe portion 10 when energized, a shield 30 provided on the radial outside of the coil portion 20 and extending in the axial direction of the pipe portion 10 to cover the coil portion 20, a fixing portion 40 provided near the inlet 101 and the outlet 102, both ends of the shield 30 in the axial direction being connected to the fixing portion 40, and a control portion 50 for controlling current in the coil portion 20, one side of the shield 30 being bulged to form a receiving space 31, the control portion 50 being provided in the receiving space 31.
In actual use, the inlet 101 and the outlet 102 of the pipe portion 10 may be connected to corresponding pipe joints, the coil portion 20 is disposed radially outside the pipe portion 10, and when the coil portion 20 is energized, an alternating magnetic field is generated in the pipe portion 10, the magnetic field penetrates the liquid metal in the pipe portion 10 and generates a sympathetic current, the current interacts with the magnetic field to generate a force along an external alternating secondary traveling wave direction, so as to push the liquid metal to advance in the pipe portion 10, and a specific position where the coil portion 20 is disposed, a winding manner of the coil portion 20, and the like are determined by those skilled in the art according to actual conditions, which is not limited in particular.
The liquid metal may be Li, na, K, naK alloy, rb, cs, alkali metal or any other suitable metal, and for metals that are liquid at normal temperature, it may be necessary to provide a heating device at the joint of the pipe portion 10 (e.g. at the inlet 101) for metals that are solid at normal temperature, to ensure that the metal entering the pipe portion 10 is liquid, and that the liquid metal is heated by the vortex effect after entering the pipe portion 10, so as not to solidify.
The fixing portion 40 is used for fixing the protective housing 30, the fixing portion 40 may be a device such as a fixing flange or other fixing devices, and the protective housing 30 may be fixed to the fixing portion 40 by a suitable manner such as a screw, a bolt, a clamping connection, welding, etc., so that a person skilled in the art can select according to the actual requirement.
One side of the protective case 30 may be bulged to form a receiving space 31, and the control part 50 may be disposed in the bulged space 31. The protective case 30 may be an integrated structure, or may be formed by splicing a plurality of cases, which is not particularly limited. In some embodiments, a partition may be formed in the accommodating space 31 to isolate the control portion 50 from the coil portion 20, and in some embodiments, a partition may not be provided. In some embodiments, the control portion 50 may be fixed to the inner wall of the protective case 30 or may be fixed to the pipe portion 10.
Unlike the large electromagnetic pump device in the related art, in the liquid metal electromagnetic pump of the embodiment of the present application, the coil portion 20 and the control portion 50, as well as the majority of the pipe portion 10, are covered by the protective case 30, which makes the entire liquid metal electromagnetic pump more compact in structure, and is particularly suitable for systems having miniaturization characteristics, such as a reactor auxiliary system or various related scientific test devices.
In some embodiments, neutron and gamma radiation are problems that equipment must face in addition to higher working fluid temperatures due to the harsh operating environment in the application scenarios such as reactors. Typically, the working temperature of the electromagnetic pump medium can reach 525 ℃, and the neutron and gamma accumulated dose is generally over 1019N/cm < 2 > and 109Gy, so that the materials used for the components in the liquid metal electromagnetic pump can be used by irradiation demonstration or verification party. Preferably, the material of the base structure of the liquid metal electromagnetic pump is selected to be unmodified, and the long-term use temperature is recommended to be 525 ℃ and below, and the liquid metal electromagnetic pump can work at 550 ℃ in a short period. The structural material of the pipe part 10 is preferably made of 316 or 316H austenitic stainless steel, has good high-temperature mechanical properties, and is compatible with alkali metal working media. The structural material of the protective shell 30 is preferably 304 or 316L austenitic stainless steel to reduce cost.
In some embodiments, the protective case 30 may be provided with a vent hole 32, and the vent hole 32 may be used for the flow of air to cool the coil part 20, the control part 50, the pipe part 10, etc. to some extent by natural air. In some embodiments, a temperature measuring device (not shown in the figure) may be provided to measure the temperature of the parts, such as the pipeline part 10, the coil part 20, the control part 50, and the like, which are easy to generate heat, and measures such as stopping working, reducing frequency, assisting cooling, and the like may be timely taken to process when the temperature exceeds the standard, so as to avoid damage to the liquid metal electromagnetic pump. Preferably, the temperature measuring device may be a thermocouple, and it is recommended to use a nickel-chromium-nickel-aluminum sheathed insulation type thermocouple having good irradiation resistance characteristics.
In some embodiments, the control portion 50 may include an axially extending electrical connection plate 51 of the pipe portion 10, and the shape of the accommodating space 31 may be adapted to the electrical connection plate 51, so that the overall volume of the liquid metal electromagnetic pump may be further reduced. The electric wiring board 51 can control the current intensity, frequency and the like in the coil part 20 to realize multiple modes of frequency modulation, current regulation, voltage regulation and work regulation of the liquid metal electromagnetic pump, is suitable for different types of control systems, can modulate any P-Q characteristic combination in an operation envelope line, and is particularly suitable for scientific test devices with wide operation range. Preferably, the electrical wiring board 51 may be made using an a-type alumina ceramic or polyimide to increase its irradiation resistance. In some embodiments, the control portion 50 may further include a communication device, which may be connected to the electrical wiring board 51 so as to enable remote control.
In some embodiments, referring to fig. 1, the liquid metal electromagnetic pump further includes a first magnetic conductive assembly 60, the first magnetic conductive assembly 60 being disposed between the coil part 20 and the protective case 30, the first magnetic conductive assembly 60 being connected with the fixing part 40 to fix the coil part 20 to the pipe part 10, and when a current is applied to the coil part 20, the current is capable of generating a magnetic field in the pipe part 10 by the first magnetic conductive assembly 60. That is, the first magnetic conductive assembly 60 can simultaneously complete the generation and guiding of the magnetic field and the fixation of the coil portion 20, and such a fixation method can reduce the fixation cost of the coil portion 20, and also make the assembly and manufacture of the liquid metal electromagnetic pump and the replacement of the parts more convenient.
In some embodiments, referring to fig. 1 and 2, the first magnetic conductive assembly 60 may include a plurality of first magnetic conductors 61, the plurality of first magnetic conductors 61 being disposed along a circumferential direction of the pipe portion 10, each first magnetic conductor 61 extending in an axial direction of the pipe portion 10, and both ends of each first magnetic conductor 61 being connected to the fixing portion 40. Preferably, the first magnetic conductive assembly 60 may include 6-8 first magnetic conductive bodies 61, and the first magnetic conductive bodies 61 may be uniformly arranged along the circumferential direction of the pipe portion 10, so as to ensure that the coil portion 20 is stressed uniformly in all directions, and avoid the coil portion 20 from vibrating greatly due to electromagnetic reasons as much as possible. The use of a plurality of first magnetic conductors 61 can further reduce manufacturing costs compared to the use of an integrated first magnetic conductive assembly 60 (e.g., a cylindrical first magnetic conductive assembly). In some embodiments, the first magnetizer 61 may be formed by stacking silicon steel sheets.
In some embodiments, the protective case 30 and the plurality of first magnetic conductors 61 are detachable from the fixing portion 40 to expose the coil portion 20. In some embodiments, the protective shell 30 and the first magnetizer 61 may be detached in case that the liquid metal electromagnetic pump is already connected to the corresponding pipeline, for example, the protective shell 30 may be spliced by a plurality of shells or folded by one shell, and a connection of the plurality of shells or a butt joint of the one shell after folding may be detachably disposed, so that after contacting the connection between the protective shell 30 and the fixing portion 40, the protective shell 30 may be removed by contacting the connection of the connection or the butt joint.
After the protective case 30 is removed, the first magnetizer 61 may be further detached from the fixing portion 40, so that the coil portion 20 is at least partially exposed, thereby enabling in-situ maintenance of the coil portion 20 without integrally removing the liquid metal electromagnetic pump. In some embodiments, two ends of the first magnetizer 61 may be connected to the fixing portion 40 by means of a snap fit, for example, two ends of the first magnetizer 61 may be provided with a snap fit, and the fixing portion 40 may be provided with a corresponding snap fit groove, so that when the first magnetizer 61 is detached, the first magnetizer 61 can be detached by means of knocking, which is further convenient for maintenance.
In some embodiments, referring to fig. 1, the coil portion 20 includes a plurality of coils 21 disposed at intervals along the axial direction of the pipe portion 10. In such an embodiment, the first magnetizer 61 may be formed with a plurality of protrusions 611, and when the first magnetizer 61 is connected with the fixing portion 40, each protrusion 611 is caught in a gap between two adjacent coils 21 to fix the coils 21. The specific number of coils 21 can be selected by those skilled in the art, and the number, length and width of the protrusions 611 are adapted to the number of coils 21 and the specific positions of the coils, which will not be described herein.
In some embodiments, each coil 21 may include a loop former 211, a wire 212 wound on the loop former 211, and a protective layer 213 covering the outside of the wire 212. The annular frame 211 can be integrally formed or formed by split splicing, and preferably, the integrally formed annular frame 211 is used for saving cost. In the actual assembly process, the annular frame 211 of the coil 21 may be directly fitted over the pipe portion 10 and then fixed by the first magnetizer 61. The protective layer 213 may be directly coated on the outer side of the wire 212 after the wire 212 is wound around the ring-shaped bobbin 211, or may be sleeved on the outer side of the wire 212 in the form of a protective ring, and the protective layer 213 in the form of a protective ring may be removed from the outer side of the wire 212 to expose the wire 212, so that the wire 212 may be individually replaced without replacing the protective layer 213 when the coil 21 fails.
In order to improve the high temperature resistance and irradiation resistance of the coil 21, the annular skeleton 211 and the protective layer 213 may be made of α -type alumina, or may be made of aluminum nitride ceramics with better thermal shock resistance, but aluminum nitride ceramics incur higher cost than α -type alumina. The conductive wire 212 can adopt dispersed copper nickel plating or silver as a conductor, and adopts radiation-resistant mica insulation ceramic fiber as an outer layer, and both mica and ceramic fiber have good radiation resistance, and because the conductive wire 212 is generally glued, the glue removal and carbon removal operation is recommended after the winding of the conductive wire 212 is completed. Preferably, the wire 212 is flexible so that, in the event of a failure, the replacement of the wire 212 can be performed in situ after the protective layer 213 has been removed directly.
In some embodiments, referring to fig. 4 and 5, the pipe portion 10 may include a pipe body 11, a second magnetic conductive assembly 12, and a support member 13, where the second magnetic conductive assembly 12 and the pipe body 11 are coaxially disposed, and the support member 13 supports the second magnetic conductive assembly 12 inside the pipe body 11 so that an annular flow channel 14 for flowing liquid metal is formed between the pipe body 11 and the second magnetic conductive assembly 12. The annular flow channel 14 can reduce the flow resistance of the liquid metal as much as possible, and improve the flow threshold of the cavitation vibration phenomenon of the fluid, thereby greatly improving the fluid stability when the liquid metal electromagnetic pump drives the liquid metal.
In some embodiments, the second magnetically permeable assembly 12 may include a housing 121 and a second magnetically permeable body 122, the housing 121 creating a vacuum environment therein, the second magnetically permeable body 122 disposed in the housing 121 and extending in an axial direction of the housing 121. The formation of a vacuum environment within housing 121 may ensure a clean interior environment of the housing, avoiding the possibility of undesirable gases (e.g., oxygen) interacting with second magnetic conductor 122. The second magnetizer 122 may be made of silicon steel, in some embodiments, the second magnetizer 122 may further include a central magnetizer 1221 and a plurality of silicon steel sheets 1222 radially embedded in the central magnetizer 1221, specifically, referring to fig. 4, grooves radially arranged along a diameter direction of the central magnetizer 1221 may be formed on the central magnetizer 1221, the silicon steel sheets 1222 are disposed in the grooves, it is recommended to use a silicon steel sheet variety with a high-temperature radiation-resistant coating, and a thickness of the silicon steel sheet may be selected between 0.2 mm and 0.5mm, for example, 0.35mm, so that the silicon steel sheet can block formation of transverse induced current, thereby improving working efficiency of the liquid metal electromagnetic pump and fluid stability of liquid metal during working.
In some embodiments, referring to fig. 5, the housing 121 may include a first housing 1211 and two second housings 1212 provided at both ends of the first housing 1211, respectively, the first housing 1211 being cylindrical, each second housing 1212 having an inner diameter gradually decreasing in a direction away from the first housing 1211. In such an embodiment, the entire housing 121 is torpedo-shaped, and the second housing 1212 with the tapered inner diameter at both ends can perform a good flow guiding function, reducing the resistance of the liquid metal flowing into the annular runner 14. To ensure a vacuum environment within housing 121, the space between first housing 1211 and second housing 1212 may be sealed by electron beam welding.
In some embodiments, the supporting member 13 may include two main supporting members 131 connected to two second housings 1212, respectively, as shown in fig. 5, an end of the main supporting member 131 away from the second housings 1212 may be fixed to the tube 11, and an end near the second housings 1212 may be screwed to the second housings 1212, or may be connected by other suitable connection methods, so as to support the second magnetic conductive assembly 12 in the tube 11.
In some embodiments, in addition to the two main supporting members 131 disposed at both ends, a plurality of auxiliary supporting members 132 disposed outside the second magnetic conductive member 12 along the axial direction of the second magnetic conductive member 12 may be further included with reference to fig. 4, thereby further securing the stability of the support. It should be noted that the main support 131 and the auxiliary support 132 are required to be provided with openings through which the liquid metal flows. Moreover, it is desirable to ensure that the primary support 131 and the secondary support 132 do not affect the flow efficiency as much as possible, for example, in some embodiments, the leading and trailing edges of the primary support 131 and the secondary support 132 along the axial direction of the pipe portion 10 may be designed in a circular arc shape, so as to better conform to the hydrodynamic characteristics and reduce the resistance to the flow of the liquid metal.
In some embodiments, the tube 11 may include a first tube 111 and two second tubes 112 disposed at both ends of the first tube 111, respectively, the second tubes 112 being partially inserted into the first tube 111 and coupled with the main support 131. Specifically, referring to fig. 5, one or more protrusions may be formed at an end of the main support 131 away from the second magnetic conductive assembly 12, and a corresponding groove may be formed on the second tube 112, so that a mating connection with the main support 131 can be formed after the second tube 112 is inserted into the first tube 111. One end of the second pipe body 112 far from the first pipe body 111 may be used for connection with a corresponding pipe, and a person skilled in the art may set the second pipe body according to an actual application scenario, which is not limited in detail. In some embodiments, the outer side of the first tube 111 may be provided with an insulating layer 113, where the insulating layer 113 is mainly used to prevent some liquid metal from solidifying during the pumping process, and may also reduce the heat conduction from the pipe portion 10 to the first magnetic conductive component 60 and the coil portion 20.
It should be noted that although the second tube 112 is cooperatively connected to the main support 131, the second tube 112 is welded to the first tube 111 to ensure tightness of the entire pipe portion 10, preferably by electron beam welding, but may be welded by tungsten gas shielding or other suitable means when the condition is not satisfied.
In some embodiments, to further ensure the tightness of the pipe portion 10, the welded portions of the various components of the pipe portion 10 may be subjected to non-destructive inspection, such as using ultrasound, eddy currents, radiation, coloring, etc., and in some embodiments, additionally or alternatively, pressure tests and tightness tests may be performed.
In some embodiments, to further ensure cleanliness of the interior of the pipe section 10, the structural material in contact with the liquid metal requires post-cleaning vacuum degassing for assembly welding, and cleanliness during assembly welding.
It should also be noted that, in the embodiments of the present application, the features of the embodiments of the present application and the features of the embodiments of the present application may be combined with each other to obtain new embodiments without conflict.
The present application is not limited to the above embodiments, but the scope of the application is defined by the claims.