Liquid metal electromagnetic pump

Abstract

A liquid metal electromagnetic pump includes: a pump trench pressure pipeline and an electromagnetic driving device. The pump trench pressure pipeline has a liquid flow inlet for receiving the inflow of liquid metal and a liquid flow outlet for delivering the liquid metal outward. The electromagnetic driving device is used to provide an electromagnetic force for driving the liquid metal to flow from the liquid flow inlet to the liquid flow outlet. The electromagnetic driving device includes: a stator core and a plurality of coil assemblies. The stator core extends axially on the radial outer side of the pump trench pressure pipeline, and a plurality of winding slots are provided along the length direction of the stator core. The plurality of coil assemblies are sleeved on the radial outer side of the pump trench pressure pipeline, and each coil assembly is arranged in a winding slot of the stator core. Among them, the coil assembly includes a coil wound by aluminum wires. The technical solution of the present invention provides a lightweight liquid metal electromagnetic pump.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic pumps, and particularly to a liquid metal electromagnetic pump. Background Art

[0002] Liquid metal electromagnetic pumps have the advantages of having no moving parts, no medium contact, good sealing performance, etc., and are currently the most widely used type of fluid propulsion equipment in the main and auxiliary systems of nuclear industry liquid metal reactors and various test and production devices using liquid metal as the working medium.

[0003] For liquid metal electromagnetic pumps used in conventional industries, in order to solve the heat dissipation problem, a cooling fan is usually used to forcibly air-cool the liquid metal electromagnetic pump. For liquid metal electromagnetic pumps used in the nuclear industry, since they must withstand a certain dose of neutron and γ-ray irradiation, in order to avoid maintenance caused by forced cooling, liquid metal electromagnetic pumps used in the nuclear industry are usually cooled by natural heat dissipation (a liquid metal electromagnetic pump using natural heat dissipation can be called a self-cooling type liquid metal electromagnetic pump).

[0004] In addition, in common application scenarios of liquid metal electromagnetic pumps, the weight factor of the liquid metal electromagnetic pump usually does not need to be considered. Therefore, liquid metal electromagnetic pumps usually have a relatively heavy self-weight. In some special application scenarios, such as certain vehicle-mounted devices or underwater devices, the total system mass is strictly limited, and it is required that the liquid metal electromagnetic pump must be lightweight. Summary of the Invention

[0005] The purpose of the present application is to provide a lightweight liquid metal electromagnetic pump.

[0006] The present application provides a liquid metal electromagnetic pump, including:

[0007] A pump trench pressure pipeline, having a liquid flow inlet for receiving the inflow of liquid metal and a liquid flow outlet for delivering liquid metal outward; and

[0008] An electromagnetic driving device for providing an electromagnetic force to drive the liquid metal to flow from the liquid flow inlet to the liquid flow outlet, the electromagnetic driving device including:

[0009] A stator core, extending axially along the radial outside of the pump trench pressure pipeline, and a plurality of winding slots are provided along the length direction of the stator core; and

[0010] A plurality of coil assemblies, sleeved on the radial outside of the pump trench pressure pipeline, and each coil assembly is arranged in a winding slot of the stator core;

[0011] Wherein, the coil assembly includes a coil wound by aluminum wire. Description of the Drawings

[0012] Other objects and advantages of the present invention will become apparent and can help to provide a comprehensive understanding of the present invention through the description of the present invention with reference to the accompanying drawings below.

[0013] Figure 1 is a schematic structural diagram of a liquid metal electromagnetic pump according to an embodiment of the present invention;

[0014] Figure 2 is Figure 1 a partially enlarged schematic diagram of the liquid metal electromagnetic pump shown;

[0015] Figure 3 is Figure 1 a schematic structural diagram of the liquid metal electromagnetic pump shown with the protective net omitted;

[0016] Figure 4 is Figure 3 a sectional view of the liquid metal electromagnetic pump shown;

[0017] Figure 5 is Figure 4 a partially enlarged view of area A shown;

[0018] Figure 6 is Figure 4 a partially enlarged view of area B shown;

[0019] Figure 7 is Figure 1 a sectional view of the liquid metal electromagnetic pump shown;

[0020] Figure 8 is Figure 7 a partially enlarged view of the liquid metal electromagnetic pump shown;

[0021] Figure 9 is Figure 4 a schematic structural diagram of the central magnetic conductor described;

[0022] Figure 10 is Figure 9 a sectional view of the central magnetic conductor shown along the C-C direction; and

[0023] Figure 11 is Figure 1 a schematic structural diagram of the protective net and the liquid leakage collection tray shown.

[0024] It should be noted that the drawings are not necessarily drawn to scale, but are only shown in a schematic manner that does not affect the understanding of the reader.

[0025] Explanation of reference numerals:

[0026] 100, Liquid metal electromagnetic pump; 10, Coil assembly; 11, Coil; 111, Connector; 12, Annular insulating plate; 13, Arc-shaped insulating plate; 20, Strip-shaped iron core; 21, Iron core slot; 30, Pump groove pressure pipeline; 31, Protrusion; 32, Step surface; 33, Interface pipe; 40, Central magnetic conductor; 41, Fins; 42, Housing; 421, Main body; 4211, First diversion section; 4212, Intermediate sleeve section; 4213, Second diversion section; 422, End; 4221, End face; 4222, First extension; 4223, Diversion section; 4224, Second extension; 43, Internal iron core; 431, Silicon steel sheet; 44, Support; 45, Connector; 51, First flange; 511, Opening; 52, Second flange; 521, Recess; 61, Leakage liquid collection tray; 62, Leakage detection element; 63, Protective net; 71, Electrical junction box; 72, Signal junction box. Detailed implementation manners

[0027] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only one embodiment of the present invention, rather than all embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in this application shall have the ordinary meanings understood by those of ordinary skill in the art to which the present invention belongs.

[0029] In the description of the embodiments of the present invention, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0030] See Figures 1 to 4 , the liquid metal electromagnetic pump 100 of the embodiment of the present invention may include: a pump groove pressure pipeline 30 and an electromagnetic driving device. The pump groove pressure pipeline 30 has a liquid flow inlet for receiving the inflow of liquid metal and a liquid flow outlet for delivering the liquid metal outward. The electromagnetic driving device is used to provide an electromagnetic force for driving the liquid metal to flow from the liquid flow inlet to the liquid flow outlet.

[0031] In the process of using the liquid metal electromagnetic pump 100 of the embodiment of the present application, the high-temperature liquid metal is driven by the electromagnetic driving device to flow into the liquid metal electromagnetic pump 100 from the liquid flow inlet and flow outwards from the liquid flow outlet, thereby realizing the pumping effect on the liquid metal.

[0032] The liquid metal may be Na, Li, K, Rb, Cs, NaK, etc.

[0033] In some embodiments, such as Figure 4 shown, the pump sump pressure pipeline 30 can be in a cylindrical shape. The two openings in the axial direction of the cylinder serve as the liquid flow inlet and the liquid flow outlet of the pump sump pressure pipeline 30 respectively.

[0034] The pump sump pressure pipeline 30 undertakes the function of containing the working medium. In nuclear-related applications, it also serves the function of radioactive containment. Therefore, there are strict requirements for material grades, manufacturing processes, inspection and testing. In terms of design, the number of welds can be reduced as much as possible to reduce the possibility of leakage of radioactive liquid metal.

[0035] In some embodiments, the electromagnetic drive device may include: a stator core disposed radially outside the pump sump pressure pipeline 30 and a plurality of coil assemblies 10. The stator core extends axially along the radial outside of the pump sump pressure pipeline 30.

[0036] The stator core is provided with a plurality of winding slots along its length direction. The coil assemblies 10 are sleeved on the radial outside of the pump sump pressure pipeline 30. Each coil assembly 10 is disposed in a winding slot of the stator core.

[0037] The coil assembly 10 includes a coil 11 wound by a wire.

[0038] In the related art, in the field of electrical equipment, it is generally considered that the comprehensive performance of manufacturing electromagnetic coils using copper conductors with high electrical conductivity is superior to that of aluminum conductors. However, for self-cooled electromagnetic pumps, in order to control the self-heat generation of the equipment, the allowable value of the current-carrying design of the coil conductor is usually low. At the same time, considering the factors of insulation temperature resistance limitation, the application of aluminum conductors with slightly poorer electrical conductivity but lower density becomes possible.

[0039] On the other hand, the liquid metal electromagnetic pump is a high-temperature device. Due to the limitation of the performance of insulation materials and the risk of oxidation of conductor metals, it is usually required that the coil temperature does not exceed the safe temperature. This safe temperature can be, for example, 250 °C. In addition, in order to control the self-heat generation of the liquid metal electromagnetic pump caused by copper loss and iron loss, the current-carrying value per unit area of the coil conductor is usually also strictly controlled, only about 3 - 4 A / mm 2 or so, and the magnetic flux density in the magnetic circuit silicon steel is also far lower than the saturation value. This makes the scheme of replacing copper conductors with aluminum wires with lower density feasible.

[0040] Therefore, in the embodiments of the present application, in order to enable the liquid metal electromagnetic pump to meet the lightweight requirements, that is, to be lightweight on the basis of ensuring the hydraulic output performance requirements under specified environmental conditions, the embodiments of the present application particularly use aluminum wires to wind the coil 11.

[0041] In some embodiments, the aluminum wire sequentially includes, from the inside out: a bare aluminum wire, an aluminum oxide insulating layer, and an organic insulating layer. The bare aluminum wire is an aluminum wire without any other insulating layer or protective layer. The organic insulating layer can be, for example, a common thin film sheath wrapped around the wire for insulation or protection. The organic insulating layer can be, for example, a polyimide film sheath.

[0042] When manufacturing the aluminum wire, a dense aluminum oxide insulating layer can be formed on the surface of the bare aluminum wire by anodic oxidation treatment first. The aluminum oxide insulating layer can not only play an insulating role but also further prevent the oxidation of the aluminum material. The thickness of the aluminum oxide insulating layer can be in the range of 4μm - 10μm. Then, a complete polyimide film sheath is wrapped around the outer layer of the wire with the aluminum oxide insulating layer to form a composite insulated magnet wire, which improves the insulation ability and isolates the air at the same time.

[0043] After the aluminum wire is wound into the coil 11, the aluminum oxide and polyimide jointly provide the inter-turn and ground insulation of the coil 11, improving the insulation ability.

[0044] When winding the coil 11, the aluminum wire can be wound around the coil skeleton. The aluminum nitride material has good thermal shock and irradiation resistance, and the coil skeleton can be made of aluminum nitride material. Or, the coil skeleton can also be made of low-cost α-aluminum oxide.

[0045] After the coil winding is completed, polyimide tape can be used for winding to form an external mechanical protection layer and prevent the coil from loosening at the same time.

[0046] In some embodiments, the coil assembly 10 may further include two axial insulating parts. The two axial insulating parts are respectively arranged on the two axial sides of the coil 11. The axial insulating part can be, for example, an annular insulating plate 12. The outer diameter of the annular insulating plate 12 is larger than the outer diameter of the coil 11. The outer diameter of the annular insulating plate 12 can be, for example, the same as the inner diameter of the stator slot. The outer diameter of the coil 11 is smaller than the inner diameter of the stator slot, so as to form a channel on the radial outer side of the coil 11 to facilitate air circulation and then reduce the temperature of the coil 11 and the stator core.

[0047] The annular insulating plate 12 can be in clearance fit with the axial slot wall of the winding slot, so that while the annular insulating plate 12 improves the ground insulation ability of the coil 11, it can also play a certain anti-vibration role.

[0048] In addition, the annular insulating plate 12 can also prevent the coil 11 from being scratched by the slot wall of the winding slot during the process of being inserted into the winding slot.

[0049] The axial insulating part can be, for example, a fiber-reinforced insulating plate. The fiber-reinforced insulating plate refers to an insulating plate strengthened by ceramic fibers and has considerable toughness. The fiber-reinforced insulating plate can be, for example, a mica fiber insulating plate or a ceramic fiber insulating plate.

[0050] In some embodiments, the coil assembly 10 may further include a radial insulating portion for insulating the coil 11 from the winding slot. There is a gap between the radial outer surface of the radial insulating portion and the radial slot wall of the winding slot, thereby allowing air to circulate to dissipate heat from the coil 11. The material of the radial insulating portion may be the same as that of the axial insulating portion or may be different from that of the axial insulating portion.

[0051] The liquid metal electromagnetic pump 100 may further include a temperature measuring element for detecting the temperature of the coil 11.

[0052] In some embodiments, a single temperature measuring element is used to measure the temperature of multiple coils 11.

[0053] In some embodiments, every 3 - 4 coils 11 are monitored for temperature using a single temperature measuring element (such as a thermocouple) to ensure the accuracy of the measurement as much as possible and avoid excessive local temperature. For example, if the number of coils 11 of the liquid metal electromagnetic pump 100 is 12, 4 temperature measuring elements can be arranged; when the number of coils 11 is 18, 6 temperature measuring elements can be arranged.

[0054] The temperature measuring element may be, for example, an insulated nickel-chromium - nickel-aluminum thermocouple.

[0055] When the temperature detected by the temperature measuring element is higher than the preset value, the liquid metal electromagnetic pump 100 may issue an alarm. The preset value is lower than the safe temperature. When the safe temperature is 250 °C, the preset value may be, for example, 200 °C or 230 °C.

[0056] Since the power input terminals of the liquid metal electromagnetic pump 100 are all made of copper, in order to avoid electrochemical corrosion at the copper-aluminum joint, the joint 111 of the coil 11 is crimped using a special copper-aluminum nose and then connected to the power terminal. The connection between the joints 111 of multiple coils 11 can be in the form of welding or riveting with an aluminum bridge piece.

[0057] The electrical conductivity of aluminum is about 60% of that of copper, but its density is only about 1 / 3 of that of copper. Through reasonable electromagnetic design, appropriately increasing the width of the winding slot, reducing the spacing between adjacent two winding slots, and at the same time increasing the cross-sectional area of the conductor, it is possible to replace the copper coil with an aluminum coil without changing the overall size of the liquid metal electromagnetic pump, and the self-heating of the electromagnetic pump does not change significantly. In some embodiments, the width of the winding slot can be 1.5 to 2.5 times the interval between adjacent two winding slots, and the diameter of the bare aluminum wire can be 2 mm or more. With such a design, it is possible to replace the copper coil with an aluminum coil without changing the overall size of the liquid metal electromagnetic pump and without significant change in the self-heating of the electromagnetic pump.

[0058] In some embodiments, refer to Figure 3 and Figure 4, the stator core includes a plurality of strip-shaped cores 20 extending axially, and these strip-shaped cores 20 are arranged at intervals in the circumferential direction on the radially outer side of the pump groove pressure pipeline 30. In some embodiments, these strip-shaped cores 20 are arranged at equal intervals in the circumferential direction on the radially outer side of the pump groove pressure pipeline 30.

[0059] Each strip-shaped core 20 is provided with a plurality of core slots 21 along the axial direction or the length direction, and the core slots 21 at the same axial position of each strip-shaped core 20 together form a winding slot of the stator core.

[0060] In such an embodiment, the radial insulating portion may include a plurality of arc-shaped insulating plates 13. The number of arc-shaped insulating plates 13 may be the same as the number of strip-shaped cores 20. The plurality of arc-shaped insulating plates 13 are arranged at intervals in the circumferential direction on the radially outer side of the coil 11, and each arc-shaped insulating plate 13 is used to insulate the coil 11 from a core slot 21. The plurality of arc-shaped insulating plates 13 are respectively used to insulate the coil 11 from the plurality of core slots 21 that form a winding slot.

[0061] It is easy to understand that each arc-shaped insulating plate 13 is arranged at a position corresponding to the radial groove wall (i.e., the bottom wall of the slot) of the core slot 21 of the coil 11. Refer to Figure 3 , the circumferential length of the arc-shaped insulating plate 13 may be greater than the circumferential length of the radial groove wall of the core slot 21 so that the arc-shaped insulating plate 13 extends out of the core slot 21.

[0062] In some embodiments, the number of strip-shaped cores 20 may be an even number, and the even number of strip-shaped cores 20 are evenly distributed in the circumferential direction on the radially outer side of the pump groove pressure pipeline 30 to facilitate the formation of a symmetric magnetic field. In Figure 7 the illustrated embodiment, the number of strip-shaped cores 20 is 6, and the 6 strip-shaped cores 20 are evenly distributed in the circumferential direction on the radially outer side of the pump groove pressure pipeline 30. In other embodiments, the number of strip-shaped cores 20 may also be 4, 8, 10, etc.

[0063] In some embodiments, the stator core may be laminated from non-oriented silicon steel sheets. It should be noted that the specific form of the stator core is not limited to this. In other embodiments, the stator core may also have other structures commonly used in the art.

[0064] Since the temperature of the liquid metal flowing into the pump groove pressure pipeline 30 is too high, the pump groove pressure pipeline 30 usually also has a relatively high temperature. An insulating layer may be provided between the stator core and the pump groove pressure pipeline 30 to hinder the radial heat transfer from the pump groove pressure pipeline 30 to the stator core direction, so as to prevent the temperature of the stator core and the coil 11 from being too high. In some embodiments, the material of the insulating layer may be a short fiber insulating felt.

[0065] In some embodiments, the electromagnetic driving device may further include: a central magnetic conductor 40 disposed radially inside the pump groove pressure pipeline 30. The central magnetic conductor 40 and the pump groove pressure pipeline 30 jointly define an annular flow channel. The liquid metal in the annular flow channel is induced to generate a current under the action of an external alternating magnetic field, and generates a force in the traveling wave direction with the external magnetic field, pushing the liquid metal forward and generating a pressure difference between the inlet and outlet of the pump groove pressure pipeline 30.

[0066] Support wings are respectively disposed at the axial two ends of the central magnetic conductor 40. The support wings include at least one fin 41 extending radially outward from the end of the central magnetic conductor 40. The central magnetic conductor 40 is welded to the inner wall of the pump groove pressure pipeline 30 through the fin 41.

[0067] The number of fins 41 may be 1. The number of fins 41 may also be multiple, such as 2, 3, 4, 5, etc. The multiple fins 41 are evenly distributed circumferentially at the end of the central magnetic conductor 40.

[0068] See Figure 5 and Figure 6 , the pipe walls at the axial two ends of the pump groove pressure pipeline 30 are axially retracted inward to form a step surface 32, and the inner end of the fin 41 abuts against the step surface 32.

[0069] The liquid metal electromagnetic pump 100 may further include two interface pipes 33, which are respectively disposed on the axial two sides of the pump groove pressure pipeline 30. The interface pipes 33 are used to connect with the pipelines for transporting liquid metal. The interface pipes 33 are inserted into the pump groove pressure pipeline 30 and abut against the outer end of the fin 41. Thus, the end of the fin 41 is clamped between the interface pipe 33 and the step surface 32, making the connection between the fin 41 and the pump groove pressure pipeline 30 more stable.

[0070] The interface pipe 33 may be welded to the pump groove pressure pipeline 30. Tungsten inert gas shielded welding may be used between the interface pipe 33 and the pump groove pressure pipeline 30. After welding, the weld needs to be subjected to 100% radiographic inspection and pressure and sealing tests.

[0071] See Figures 8 to 10 , the central magnetic conductor 40 includes: a housing 42 and an internal iron core 43 disposed inside the housing 42. In some embodiments, the support wings are disposed at the axial ends of the housing 42. The internal iron core 43 is in contact with the housing 42.

[0072] The housing 42 may include a main body portion 421 and two end portions 422 respectively connected to the axial two ends of the main body portion 421.

[0073] The main body portion 421 sequentially includes a first flow guiding section 4211 with a gradually increasing inner diameter along the axial direction, an intermediate sleeve section 4212 with a uniform inner diameter, and a second flow guiding section 4213 with a gradually decreasing inner diameter along the axial direction. The first flow guiding section 4211, the intermediate sleeve section 4212, and the second flow guiding section 4213 are welded to each other to form a sealed chamber inside the housing 42. The internal iron core 43 is arranged in the sealed chamber inside the housing 42.

[0074] An annular flow passage for the liquid metal to flow through, which is communicated with the liquid flow inlet and the liquid flow outlet, is formed between the outer surface of the housing 42 and the inner surface of the pump trench pressure pipeline 30.

[0075] The end portion 422 sequentially includes an end face 4221, a first extension portion 4222 with a uniform inner diameter, a flow guiding section 4223 with a gradually increasing inner diameter, and a second extension portion 4224 with a uniform inner diameter from the outside to the inside along the axial direction. The second extension portion 4224 is connected to the first flow guiding section 4211 or the second flow guiding section 4213. In other words, the second extension portions 4224 of the two end portions 422 are respectively connected to the first flow guiding section 4211 and the second flow guiding section 4213.

[0076] Through the above design of the end portion 422 and the main body portion 421 of the housing 42, the annular flow passage jointly constructed by the housing 42 and the pump trench pressure pipeline 30 can minimize the flow resistance of the liquid metal and reduce the turbulence of the liquid metal at the same time.

[0077] The support wings are arranged on the second extension portion 4224. The wing pieces 41 of the support wings are circumferentially spaced and supported in the annular flow passage between the housing 42 and the pump trench pressure pipeline 30, so as not to affect the flow of the liquid metal in the annular flow passage and to firmly hold the housing 42 inside the pump trench pressure pipeline 30.

[0078] In some embodiments of the present application, the inside of the housing 42 can be set as a vacuum chamber, and the internal iron core 43 is arranged in the vacuum chamber, so as to avoid the gas inside the housing 42 from leaking into the liquid metal working medium and polluting the liquid metal and endangering the thermal safety of the reactor core after the weld of the housing 42 fails.

[0079] The housing 42 can be welded by electron beam welding or tungsten inert gas shielded welding process. A special vacuum extraction pipe can be arranged in the first flow guiding section 4211 or the second flow guiding section 4213 of the housing 42. After the main body portion 421 of the housing 42 is welded and sealed, the inside of the housing 42 is evacuated and sealed through the vacuum extraction pipe.

[0080] In some embodiments, the central magnetic conductor 40 may further include: two support members 44 disposed in the sealed chamber of the housing 42 and a connecting member 45 connecting the two support members 44. Axial ends of the inner iron core 43 are mounted on the support members 44. The support members 44 are mounted inside the intermediate sleeve section 4212, and the outer sides of the support members 44 are the first diversion section 4211 or the second diversion section 4213.

[0081] In some embodiments, the inner iron core 43 may be formed by stacking a plurality of axially extending silicon steel sheets 431 circumferentially. The thickness of the silicon steel sheets 431 may be 0.2 to 0.5 mm. A high-temperature radiation-resistant coating may be provided on the surfaces of the silicon steel sheets 431.

[0082] It should be noted that the specific form of the inner iron core 43 is not limited thereto. In other embodiments, the inner iron core 43 may also have other structures commonly used in the art.

[0083] See Figures 1 to 4 , in some embodiments, the liquid metal electromagnetic pump 100 may further include: two mounting assemblies for mounting the pump trench pressure pipeline 30 and the stator core together. The two mounting assemblies are respectively disposed at the axial two ends of the pump trench pressure pipeline 30 and the stator core. That is, each mounting assembly is disposed at one axial end of the pump trench pressure pipeline 30 and the stator core.

[0084] The mounting assembly may include: a first flange 51 and a second flange 52. The first flange 51 is sleeved on one axial side of the pump trench pressure pipeline 30 and is detachably connected to the corresponding axial end of the stator core. The second flange 52 is sleeved on the pump trench pressure pipeline 30 outside the first flange 51 (i.e., on the side away from the stator core) for restricting the radial movement of the pump trench pressure pipeline 30. The second flange 52 is detachably connected to the first flange 51.

[0085] See Figure 5 , a convex portion 31 extending radially outward is formed on one axial side of the pump trench pressure pipeline 30, and the convex portion 31 is clamped by the first flange 51 and the second flange 52 on the corresponding side to restrict the axial movement of the pump trench pressure pipeline 30.

[0086] It is easy to understand that in the above embodiments, a convex portion 31 is formed on one axial side of the pump trench pressure pipeline 30 (see Figure 5 ), and no convex portion 31 is formed on the other side (see Figure 6 ).

[0087] Under normal circumstances, when the liquid metal electromagnetic pump 100 is operating, the temperature of the pump groove pressure pipeline 30 is always higher than that of the stator core, resulting in a thermal expansion difference between the pump groove pressure pipeline 30 and the stator core due to the temperature difference. If both axial sides of the pump groove pressure pipeline 30 and the stator core are fixed, a large stress will be generated between the pump groove pressure pipeline 30 and the stator core due to the aforementioned thermal expansion difference. In the pump groove pressure pipeline 30 of the embodiment of the present application, the raised portion 31 is fixed to the stator core at a single end, while the other end of the pump groove pressure pipeline 30 is only restricted radially by the second flange 52 and is in a free state axially, thereby avoiding a large stress between the pump groove pressure pipeline 30 and the stator core.

[0088] In some embodiments, the raised portion 31 may be an annular structure coaxial with the pump groove pressure pipeline 30. Alternatively, the raised portion 31 may be a plurality of raised portions arranged at intervals, and these raised portions are located within a circle coaxial with the pump groove pressure pipeline 30.

[0089] A stepped surface is formed on the part of the second flange 52 corresponding to the raised portion 31. The stepped surface cooperates with the raised portion 31 to restrict the movement of the raised portion 31 axially and radially.

[0090] See Figure 2 and Figure 7 , the first flange 51 has a plurality of openings 511 penetrating through its inner and outer axial surfaces, and the openings 511 are located radially outside the second flange 52.

[0091] The number of the openings 511 may be the same as the number of the bar-shaped cores 20. The positions of the openings 511 are staggered from those of the bar-shaped cores 20. That is, the openings 511 are aligned with the positions between two adjacent bar-shaped cores 20 (i.e., the openings 511 are aligned with the parts of the coil 11 located outside the core slots 21), so that natural convection can be formed through the openings 511 on both axial sides to dissipate heat from the coil 11. In addition, these openings 511 can also reduce the weight of the first flange 51.

[0092] The second flange 52 has a plurality of recesses 521 formed by inward depressions from its outer radial surface, which are used to reduce the weight of the second flange 52 as much as possible.

[0093] In some embodiments, the liquid metal electromagnetic pump 100 further includes: a liquid leakage collection tray 61 and a leakage detection element 62.

[0094] The liquid leakage collection tray 61 is arranged below the stator core and is used to collect the liquid metal leaking from the pump groove pressure pipeline 30. The leakage detection element 62 is arranged in the liquid leakage collection tray 61 and is used to detect whether the liquid metal leaks. The number of the leakage detection elements 62 may be one or more.

[0095] It is easy to understand that even though the probability of liquid metal leakage in the pump trench pressure pipeline 30 is extremely low, in some embodiments, a detachable liquid leakage collection tray 61 is still provided. The leaked liquid metal will fall on it and conduct the leakage detection element 62 arranged inside it.

[0096] The liquid metal electromagnetic pump 100 may further include: a protective net 63, sleeved outside the stator core and detachably mounted on the first flange 51. The self-weight of the mesh structure of the protective net 63 is relatively light, and it can be made of stainless steel or titanium alloy.

[0097] Both axial ends of the protective net 63 can be installed on the radial outer surface of the first flange 51 through fasteners. Refer to Figure 7 , there is a gap between the radial inner surface of the protective net 63 and the radial outer surface of the first flange 51. This gap can be, for example, 1 - 5 cm. The existence of this gap is conducive to the convection of air inside the protective net 63 and is conducive to dissipating heat from the coil 11 and the stator core.

[0098] Refer to Figure 11 , the liquid leakage collection tray 61 is arranged on the protective net 63. For example, the liquid leakage collection tray 61 is detachably mounted on the protective net 63 through fasteners. An opening can be formed in the lower part of the protective net 63, and the liquid leakage collection tray 61 is detachably mounted at this opening.

[0099] The liquid metal electromagnetic pump 100 further includes: an electrical junction box 71 and a signal junction box 72. The protective net 63 is provided with relief holes corresponding to the positions of the electrical junction box 71 and the signal junction box 72. The electrical junction box 71 and the signal junction box 72 are arranged separately. The electrical junction box 71 and the signal junction box 72 can be respectively mounted on two first flanges 51.

[0100] An electrical wiring board is provided inside the electrical junction box 71. The insulating bottom plate material can be α - type alumina ceramic or polyimide. The power supply electrode can be made of nickel - plated copper alloy to ensure the electrical conductivity while also increasing the environmental resistance. The connection between the joint 111 of the coil 11 and the power supply electrode can use a special copper - aluminum joint.

[0101] The signal junction box 72 is connected to the leakage detection element 62 and the temperature detection element. Specifically, the electrical junction box 71 can be provided with joints connected to plug - in thermocouples and joints connected to plug - in leakage detectors.

[0102] In some embodiments, the liquid metal electromagnetic pump 100 may further include: a heating element, arranged on the interface pipe 33 upstream of the liquid flow inlet. The heating element is used to heat the liquid metal entering the pump trench pressure pipeline 30 to make it in a flowing liquid state. The heating element can be, for example, at least one electric heater. The number of electric heaters can be 1, 2, 3, etc.

[0103] It is easy to understand that when using the liquid metal electromagnetic pump 100 to propel normal temperature liquid working medium such as NaK alloy, the electric heater can be turned off.

[0104] In the embodiment of the present application, since the pump groove pressure pipeline 30 must meet the requirements of working medium compatibility and the overall device process system, it is usually made of austenitic stainless steel. Other structural components, such as the first flange 51, the second flange 52, the liquid leakage collection tray 61, the support member 44, and the connecting member 45, etc., can be made of titanium alloy with low density and high strength under the condition of ensuring strength to solve the irradiation environmental conditions, so as to further reduce the total mass of the liquid metal electromagnetic pump.

[0105] The embodiment of the present application combines the three factors of material, process, and design to make the liquid metal electromagnetic pump lightweight on the basis of ensuring the hydraulic output performance requirements under specified environmental conditions.

[0106] Although the manufacturing cost of the lightweight electromagnetic pump in the embodiment of the present application is slightly increased compared with that of the non-lightweight electromagnetic pump, the requirements for fixing or supporting the corresponding equipment are reduced, and the total mass of the system is reduced. In the application scenario of the lightweight system, the total cost does not increase significantly.

[0107] The operating characteristics of the lightweight liquid metal electromagnetic pump 100 in the embodiment of the present application are the same as those of the non-lightweight self-cooled annular linear induction electromagnetic pump, supporting multiple operation modes such as frequency modulation, flow regulation, voltage regulation, and power regulation, and supporting full-range adjustment of output.

[0108] The liquid metal electromagnetic pump 100 in the embodiment of the present application is suitable for various occasions of liquid metal propulsion, such as being applicable to the nuclear irradiation environment; it is especially suitable for liquid metal propulsion in occasions with lightweight requirements, especially applicable to special conditions requiring lightweight and inconvenient maintenance, such as certain vehicle-mounted and underwater devices.

[0109] Under the condition of the same hydraulic work output of the liquid metal electromagnetic pump 100 of the present invention, the weight is reduced by more than 30%, having obvious lightweight characteristics, and the greater the equipment, the more obvious the weight reduction effect.

[0110] For the embodiments of the present invention, it should also be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0111] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A liquid metal electromagnetic pump, characterized in that, it comprises: a pump groove pressure pipeline, having a liquid flow inlet for receiving the inflow of liquid metal and a liquid flow outlet for delivering the liquid metal outwards; and an electromagnetic driving device for providing an electromagnetic force to drive the liquid metal to flow from the liquid flow inlet to the liquid flow outlet, the electromagnetic driving device comprising: a stator core, extending axially on the radial outer side of the pump groove pressure pipeline, and a plurality of winding slots are provided along the length direction of the stator core; and a plurality of coil assemblies, sleeved on the radial outer side of the pump groove pressure pipeline, and each coil assembly is arranged in a winding slot of the stator core; wherein, the coil assembly comprises a coil wound by aluminum wires; the electromagnetic driving device further comprises a central magnetic conductor, arranged on the radial inner side of the pump groove pressure pipeline; support wings are respectively arranged at the axial two ends of the central magnetic conductor, the support wing comprises at least one fin extending radially outwards from the end of the central magnetic conductor, and the central magnetic conductor is welded to the inner wall of the pump groove pressure pipeline through the fin; the central magnetic conductor comprises: a housing, and the support wing is arranged at the axial end of the housing; the housing comprises a main body part and two end parts respectively connected to the axial two ends of the main body part, wherein the main body part sequentially comprises a first diversion section with a gradually expanding outer diameter, an intermediate sleeve section with a uniform outer diameter, and a second diversion section with a gradually shrinking outer diameter along the axial direction; the end part sequentially comprises an end face, a first extension part with a uniform outer diameter, a diversion section with a gradually expanding outer diameter, and a second extension part with a uniform outer diameter from the outside to the inside along the axial direction, wherein, the second extension part is connected to the first diversion section or the second diversion section, and the support wing is arranged on the second extension part.

2. The liquid metal electromagnetic pump according to claim 1, characterized in that, the aluminum wire sequentially comprises from the inside to the outside: a bare aluminum wire, an alumina insulating layer, and an organic insulating layer.

3. The liquid metal electromagnetic pump according to claim 1, characterized in that, the coil assembly further comprises two axial insulating parts, respectively arranged on the axial two sides of the coil.

4. The liquid metal electromagnetic pump according to claim 3, characterized in that, the axial insulating part is an annular insulating plate.

5. The liquid metal electromagnetic pump according to claim 4, characterized in that, the annular insulating plate is in clearance fit with the axial groove wall of the winding slot.

6. The liquid metal electromagnetic pump according to claim 3, characterized in that, the coil assembly further comprises: a radial insulating part, arranged on the radial outer side of the coil for insulating the coil from the winding slot.

7. The liquid metal electromagnetic pump according to claim 1, characterized in that, it further comprises: two mounting components for mounting the pump groove pressure pipeline and the stator core together, and the two mounting components are respectively arranged at the axial two ends of the pump groove pressure pipeline and the stator core.

8. The liquid metal electromagnetic pump according to claim 7, characterized in that, each mounting component comprises: A first flange is sleeved on one axial side of the pump sump pressure pipeline and is detachably connected to a corresponding axial end of the stator core; and A second flange is sleeved on the pump sump pressure pipeline outside the first flange for restricting radial movement of the pump sump pressure pipeline, and the second flange is detachably connected to the first flange; A convex portion extending radially outward is formed on one axial side of the pump sump pressure pipeline, and the convex portion is clamped by the first flange and the second flange on the corresponding side to restrict axial movement of the pump sump pressure pipeline.

9. The liquid metal electromagnetic pump according to claim 8, wherein, The first flange has a plurality of openings penetrating through its inner and outer axial surfaces, and the openings are located radially outside the second flange; The second flange has a plurality of recesses formed by inward depression from its radially outer surface.

10. The liquid metal electromagnetic pump according to claim 1, wherein, The stator core includes a plurality of strip-shaped cores extending axially and arranged circumferentially at intervals on the radial outside of the pump sump pressure pipeline. Each strip-shaped core is provided with a plurality of core slots axially, and the core slots at the same axial position of the plurality of strip-shaped cores jointly form a winding slot.

11. The liquid metal electromagnetic pump according to claim 1, wherein, A heat insulation layer is further provided between the stator core and the pump sump pressure pipeline.

12. The liquid metal electromagnetic pump according to claim 1, wherein, The pipe walls at both axial ends of the pump sump pressure pipeline are axially retracted inward to form step surfaces, and the inner ends of the fins are abutted against the step surfaces.

13. The liquid metal electromagnetic pump according to claim 12, wherein, It further includes two interface pipes respectively arranged on both axial sides of the pump sump pressure pipeline. The interface pipes are inserted into the pump sump pressure pipeline and are abutted against the outer ends of the fins; The interface pipes are welded to the pump sump pressure pipeline.

14. The liquid metal electromagnetic pump according to claim 1, wherein, The central magnetic conductor further includes: An inner iron core is arranged inside the housing and is in contact with the housing.

15. The liquid metal electromagnetic pump according to claim 8, wherein, It further includes: A liquid leakage collection tray is arranged below the stator core for collecting liquid metal leaking from the pump sump pressure pipeline; and A leakage detection element is arranged in the liquid leakage collection tray for detecting whether liquid metal leaks.

16. The liquid metal electromagnetic pump according to claim 15, wherein, It further includes: A protective net is sleeved outside the stator core and is detachably installed on the first flange; wherein, the liquid leakage collection tray is arranged on the protective net.

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