JPH0965641A - Electromagnetic pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the efficiency of an electromagnetic pump by reducing the eddy current loss of a double duct. SOLUTION: An electromagnetic pump has a double duct 5 in which a conductive fluid is made to flow through an annular flow passages defined by an outer duct 3 and an inner duct incorporated in the duct 3, inner and outer laminated iron cores 11 and 7 which are respectively arranged radially on the inside of the inner duct 4 and the outside of the outer duct 3, and stator coils 10 and 15 which are housed in the slots formed in the cores 11 and 7 on at least one duct side and drive the fluid by generating traveling magnetic fields. The duct 5 is formed of an particle dispersion composite material obtained by adding particles of a metal oxide or metal nitride to a nonmagnetic matrix base material composed mainly of austenitic stainless steel or nickel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic field that applies a traveling magnetic field to a conductive fluid from outside to induce an induced current in the conductive fluid and causes a pumping action by the interaction between the induced current and the external magnetic field. The present invention relates to a pump, and more particularly to an electromagnetic pump suitable as a circulating pump for sodium coolant for a fast breeder reactor, lysium for a fusion reactor, a liquid metal transfer pump for electromagnetic metallurgy, and the like.

[0002]

2. Description of the Related Art Generally, in a three-phase induction type electromagnetic pump, three-phase AC windings are arranged in the direction of flow of the electromagnetic pump in the order of respective phases, and three-phase AC currents are supplied to the three-phase AC windings. To generate a traveling magnetic field in the direction of the current flow, and the traveling magnetic field is passed through the duct in which the conductive fluid is present. Then, Fleming's right-hand rule induces a voltage in the conductive fluid, which causes an induced current to flow. This induced current and a part of the component of the traveling magnetic field act to generate an electromagnetic force, which acts as a pump because it receives a force for flowing a conductive fluid. This electromagnetic force is the same as the torque in the induction motor and the thrust in the linear motor.

This three-phase induction type electromagnetic pump is roughly classified into two types, that is, a flat linear type electromagnetic pump and an annular linear type electromagnetic pump in terms of structure. The electromagnetic pump of the present invention relates to an improvement of the annular linear type electromagnetic pump, and the annular linear type electromagnetic pump has an annular flow passage cross section of the conductive fluid.
It is called an ALIP (Annular Linear Induction Pump) and is used as a large capacity pump and a conductive fluid pump that requires high reliability because of its highly reliable and safe duct structure.

The basic structure of the ALIP is shown in FIG. This electromagnetic pump 1 has a double duct 5 having a concentric double pipe structure with an outer duct 3 and an inner duct 4 for pumping a conductive fluid 2 such as liquid metal sodium, which is indicated by an arrow, from a suction port to a discharge port. And an annular annulus flow path 6 defined by the outer and inner ducts 3 and 4 is formed, and the conductive fluid 2 is passed through the annulus flow path 6.

On the outer side of the outer duct 3, an outer laminated iron core 7 in which a plurality of electric iron plates are stacked in the circumferential direction is arranged with a gap 8 in the diametrical direction, and the plural laminated iron cores 7 are equally distributed in the circumferential direction. Then, an annular outer stator coil (stator) 10 is provided in each of the plurality of slots 9 formed in each outer laminated iron core 7.
Are fitted and fixed to form a magnetic circuit of an alternating magnetic field. In this case, the outer laminated iron core 7 is radially provided so that the slots 9 and the outer stator coils 10 are located on the inner side (the outer duct 3 side). A large number of outer stator coils 10 are arranged at a predetermined pitch in the axial direction of the outer duct 3 and are connected so that a three-phase alternating current produces a traveling magnetic field.

An inner laminated iron core 11 for forming a magnetic circuit is housed inside the inner duct 4.
As a result, the conductive fluid 2 is a fluid inlet 12 that is a suction port.
While flowing through the annulus flow path 6 from, a voltage is induced by receiving a traveling magnetic field and is pressure-fed to the outside from the fluid outlet 13 which is a discharge port.

Further, in order to increase the capacity and the size of the electromagnetic pump 1, an inner stator coil 15 is also arranged in the inner iron core 11 and is excited by the outer stator coil 10 and the inner stator coil 15. As a result, the traveling magnetic field is enhanced to enhance the pump force.

Further, in recent years, consideration has been given to adopting the electromagnetic pump 1 with a large capacity as a circulation pump of the main circulation system of a fast reactor, and an important requirement for this is that the inner duct 4 is In addition to the miniaturization of the electromagnetic pump by arranging the stator coil inside, double stator,
It is an important requirement to improve the operation efficiency of the electromagnetic pump 1. In addition, the casing 14 may cover the entire electromagnetic pump 1 in a hermetically sealed manner, and may be used by being immersed in the conductive fluid 2.

[0009]

However, in such a large-capacity conventional electromagnetic pump, since the outer and inner ducts 3 and 4 are made of metal such as austenitic stainless steel, these ducts 3 and 4 are used. On the other hand, since the eddy power flows due to the difference from the traveling speed of the magnetic field, the Joule loss is generated, which causes a significant decrease in pump efficiency. When the loss is analyzed, the eddy current loss in the outer duct 3 and the inner duct 4 is about 20%.
Therefore, it is important to take measures to reduce this loss.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a high-performance electromagnetic pump capable of reducing eddy current loss of a double duct and improving pump efficiency. It is in.

[0011]

According to the invention of claim 1, a double duct for flowing a conductive fluid in an annular flow passage defined by an outer duct and an inner duct built in the outer duct, and the inner duct. Inner and outer laminated cores arranged outside the inner and outer ducts and a slot formed on the duct side of at least one of the inner and outer laminated cores, and the conductive fluid is generated by the traveling magnetic field formed. In the electromagnetic pump having a stator coil for driving the double duct, particles of either a metal oxide or a metal nitride are added to a non-magnetic matrix base metal containing austenitic stainless steel or nickel as a main component. Was formed from a particle-dispersed composite material to which was added.

Therefore, according to the present invention, the double duct is formed by adding particles of either a metal oxide or a metal nitride to a non-magnetic matrix base metal whose main component is austenitic stainless steel or nickel. Since it is made of the dispersed composite material, the electrical resistance of the double duct can be increased while the eddy current loss can be reduced. Therefore, it is possible to improve the pump efficiency and provide a highly efficient, downsized, large-capacity electromagnetic pump.

The invention of claim 2 is the invention according to claim 1, wherein the particle-dispersed composite material comprises austenitic stainless steel or a non-magnetic alloy powder containing nickel as a main component, and a metal oxide. Alternatively, it is formed by adding and mixing any powder particles of metal nitride and sintering by hot isostatic pressing.

Therefore, according to the present invention, a powder of austenitic stainless steel or nickel or a non-magnetic alloy containing nickel as a main component and a powder of a metal oxide or a metal nitride are added and mixed, and a hot isostatic pressing method (HIP) is used. Since it is a method of producing a particle-dispersed composite material by sintering in step 1), it is most advantageous as a method of producing a new composite material that is homogeneous and has high electric resistance.
In this case, the average particle size of the matrix base material is about 50 μm or less, and the average particle size of the dispersed alumina powder particles is about 0.5 μm or less. By using small powder particles having a particle size of about 2 digits or less, a particle-dispersed composite material having high electric resistance can be obtained.

The invention according to claim 3 is the invention according to claim 1 or 2, wherein the powder particles of either the metal oxide or the metal nitride are alumina particles.

Therefore, according to the present invention, since the alumina particles which are stable in the metal base material are used as the powder particles of the metal oxide or the metal nitride according to claim 1 or 2, the electrical resistivity ratio is improved. Can be significantly increased. For example, the content of alumina is 5% to 8
When it is 0%, the electrical resistivity ratio can be about 1.5 to about 100 times or more. However, if the content of alumina is increased, there are problems in strength reduction and processing.
About 0% is desirable.

According to a fourth aspect of the present invention, there is provided a double duct for flowing a conductive fluid in an annular flow passage defined by an outer duct and an inner duct built in the outer duct, and an inner duct and an outer duct of the inner duct. Inner and outer laminated iron cores arranged on the outer side and a stator coil which is housed in a slot formed on the duct side of at least one of the inner and outer laminated iron cores and drives the conductive fluid by the traveling magnetic field formed. In an electromagnetic pump having, the both ends of the double duct projecting axially outward more than the axial ends of at least one of the inner and outer laminated iron cores are made of a magnetic material of ferritic stainless steel or ferritic chromium alloy steel. Made of material.

Therefore, in the conventional electromagnetic pump, a magnetic field is suddenly generated in the sodium flow direction at the inlet end, and
At the outlet end, the magnetic field is suddenly attenuated, so that thrust in the direction opposite to the sodium flow direction acts. This is a factor that reduces the discharge pressure of the pump as an end effect. However, according to the present invention, since the end of the double duct is made of ferritic steel, the attenuation of the magnetic field at the end of the electromagnetic pump can be slowed down. Therefore, the reverse thrust is reduced, and the efficiency is expected to be improved. In fact, according to the trial calculation, an additional efficiency of about 3% can be expected by additionally installing the ferrite duct at the end.

According to a fifth aspect of the present invention, a double duct for causing a conductive fluid to flow in an annular flow passage defined by an outer duct and an inner duct built in the outer duct, and an inner duct and an outer duct of the inner duct. Inner and outer laminated iron cores arranged on the outer side and a stator coil which is housed in a slot formed on the duct side of at least one of the inner and outer laminated iron cores and drives the conductive fluid by the traveling magnetic field formed. In the electromagnetic pump having, magnetic materials are attached to the outer peripheries of both ends of the outer duct projecting axially outwardly of both axial ends of at least one of the inner and outer laminated iron cores.

Therefore, according to the present invention, the above-mentioned claim 4
Similarly to the invention described above, the damping of the magnetic field at the end of the electromagnetic pump can be easily realized, and the pump efficiency can be improved.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
~ It demonstrates based on FIG. In addition, in FIG.
The same reference numerals are given to the same or corresponding portions as those indicated by.

FIG. 1 shows a first electromagnetic pump 21 according to the present invention.
2 is a sectional view taken along the line II-II of FIG. 1. In these drawings, the electromagnetic pump 21 includes an outer duct 3 and an inner duct 4 which are made of austenitic stainless steel or nickel. The main feature is that the matrix base material of the non-magnetic alloy, which is the main component, is composed of a particle dispersion type composite material obtained by adding particles of either a metal oxide or a metal nitride. As the matrix base material, for example, austenitic stainless steel of SUS304, SUS316, nickel alloy such as Inconel 625 is used, and as the metal oxide or metal nitride, alumina stable in the metal base material, Silicon carbide, silicon nitride, zirconium oxide, spinel are used as promising composite dispersions.

FIG. 3 shows the above alumina content (volume percentage).
And the electrical resistivity ratio of the high electrical resistance material of the outer and inner ducts 3 and 4 (the electrical resistivity of stainless is 1.0). That is, FIG. 3 shows SUS316 and Inconel 625.
Alumina particles in the base material, each showing the material properties of dispersed inclusion, as the alumina content increases,
There is a characteristic that the electric resistivity ratio is considerably increased, and when the content of alumina is 5% to 80% (volume%), the electric resistivity ratio becomes about 1.5 to about 100 times or more.

However, if the content of alumina is increased,
As shown in FIG. 4, there is a problem in the strength of the double duct 5 and processing problems. Note that FIG. 5 shows a comparison of the electrical resistivity before and after the test piece containing aluminum in the base material of Inconel 625 is immersed in liquid metal sodium which is a conductive fluid, and FIG.
It shows a similar electrical resistivity comparison when 25 is replaced with SUS316.

As a method for producing a composite material having a high electric resistance by dispersing alumina particles in the austenitic stainless steel or the matrix base material of Inconel, austenitic stainless steel or nickel containing nickel as a main component is used. A method of making a particle-dispersed composite material by adding powders of a magnetic alloy and powders of a metal oxide or a metal nitride and sintering them by a hot isostatic pressing method (HIP) is homogeneous and has high electric resistance. It is the most advantageous as a method of producing a new composite material that can be made expensive. In this case, the average particle size of the matrix base material is about 50 μm or less, and the average particle size of the dispersed alumina powder particles is about 0.5 μm or less. By using small powder particles having a particle size of about 2 digits or less, a particle-dispersed composite material having high electric resistance can be obtained.

Therefore, according to this embodiment, the eddy current loss in the outer duct 3 and the inner duct 4 can be reduced, so that the pump efficiency is about 10 to 20 as shown in FIG.
%, The efficiency defined by the ratio of fluid power to pump input = flow rate * discharge pressure can be expected to be as high as about 50-60%. In this embodiment, the high electric composite material is used for both the outer duct 3 and the inner duct 4, but the high electric composite material may be applied to only one of them.

In the second embodiment of the present invention, as shown in FIG. 2, the inlet side diffuser 17 on the fluid inlet side 12 of the outer duct 3 connected to the inlet pipe 16 is also mainly made of austenitic stainless steel or nickel. It is composed of a composite material in which particles of a metal oxide or a metal nitride are added and dispersed in a matrix matrix alloy as a component.

Further, the outlet side diffuser 19 connected to the outlet pipe 18 on the fluid outlet side 13 of the outer duct 3 is made of austenitic stainless steel or a matrix matrix alloy containing nickel as a main component, a metal oxide or a metal. It is made of a composite material in which particles of nitride are added and dispersed. In this case, the outer duct 3 and the inlet pipe 16,
As shown in FIG. 8, the welded portion 3c welded to the outlet pipe 18 and its peripheral portion (VI portion in FIG. 2) are connected to the inlet pipe 16 or the outlet from the inlet / outlet side diffusers 17, 19 of the outer duct 3, respectively. The functionally graded material structure 22 is configured to gradually reduce the alumina content toward the pipe 18.

Therefore, according to this embodiment, the inlet pipe 16 or the outlet pipe 18 and the diffusers 17, 19 of the outer duct 3 can be welded easily, so that the manufacturability is improved and the reliability of the duct member is improved. The property is improved.

In the third embodiment of the present invention, as shown in FIG. 2, the axial directions of the outer and inner ducts 3 and 4 projecting axially outward more than the axial ends of the outer and inner laminated cores 7 and 11 respectively. Both ends 3a, 3b, 4a, 4b are made of ferritic stainless steel, or 2-1 / 4Cr-1Mo steel, Mo.
d. It is composed of ferritic chromium steel of 1Cr-9Cr-1Mo steel. In this case, a composite material in which alumina particles are dispersed is used in the area surrounded by the outer and inner laminated iron cores 7 and 11 of the electromagnetic pump 21, and the outer and inner ducts 3 axially outer than the iron cores 7 and 11 are used. , 4 that is, the diffusers 17 and 19 are made of the above-mentioned ferritic stainless steel or ferritic chromium alloy steel.

Therefore, in the conventional electromagnetic pump, a magnetic field is suddenly generated in the flow direction of the liquid metal sodium at the end of the fluid inlet 12 and the magnetic field is suddenly attenuated at the end of the fluid outlet 13. , The thrust in the direction opposite to the flow direction of the liquid metal sodium acts to reduce the discharge pressure of the pump, but in the present embodiment, both axial end portions 3a, 3b, 4a of the outer and inner ducts 3, 4 are Since 4b is made of ferritic steel, the attenuation of the magnetic field at the end of the electromagnetic pump 21 can be slowed down. Therefore, the reverse thrust is reduced,
Pump efficiency is improved. In fact, according to the trial calculation, an additional efficiency of about 3% can be expected by additionally installing the ferrite duct at the end.

FIG. 9 is a longitudinal sectional view of a fourth embodiment of the present invention, which is characterized mainly in that a magnetic piece 23 is fixed to the outer surfaces of both diffusers 19 and 17 on the entrance and exit sides of the outer duct 3. Have. Each magnetic piece 23 is associated with each diffuser 17, 1
9 by welding or the like, or the diffuser 17,
19 is pressed against the outer peripheral surface, and the outer periphery is fastened with the fastening band 24
It may be fixed by. In the present embodiment, the magnetic piece 2
3 is provided in each diffuser 17, 19, but the present invention is not limited to this case, and for example, outer and inner laminated cores 7, 11
The magnetic piece 23 may be provided at the extending portion of the double duct 5 that extends axially outward from the. Further, the magnetic piece 23 may be formed in a strip shape divided into a plurality of pieces in the circumferential direction, or a ring or a piece obtained by dividing a ring into a plurality of pieces.

Furthermore, each of the above embodiments has been described as applied to the double stator electromagnetic pump 21 in which the stator coils 10 and 15 are arranged inside and outside the double duct 5.
Each of these embodiments is, for example, the outer stator 1 shown in FIG.
The present invention can also be applied to the electromagnetic pump 31 having only 0 or the electromagnetic pump having only the inner stator coil 15 (not shown).

[0034]

As described above, according to the invention of claim 1 of the present application, the double duct is formed by adding a metal oxide or metal to the non-magnetic matrix base metal containing austenitic stainless steel or nickel as a main component. Since it is formed of the particle-dispersed composite material to which any of the nitride particles is added, it is possible to increase the electric resistance of the double duct and reduce the eddy current loss. Therefore, it is possible to improve the pump efficiency and provide a highly efficient, downsized, large-capacity electromagnetic pump.

According to a second aspect of the present invention, the powder of austenitic stainless steel or non-magnetic alloy containing nickel or the main component and the powder of metal oxide or metal nitride are added and mixed, and the hot isostatic pressing (HIP) method is used. Since it is a method of producing a particle-dispersed composite material by sintering in step 1), it is most advantageous as a method of producing a new composite material that is homogeneous and has high electric resistance. In this case, the average particle size of the matrix base material is about 50 μm or less, and the average particle size of the dispersed alumina powder particles is about 0.5 μm or less. By using small powder particles having a particle size of about 2 digits or less, a particle-dispersed composite material having high electric resistance can be obtained.

According to the invention of claim 3, alumina particles which are stable in the metal base material are used as the powder particles of the metal oxide or the metal nitride according to claim 1 or 2. Can be significantly increased. For example, when the content of alumina is 5% to 80%, the electrical resistivity ratio can be about 1.5 to about 100 times or more.

According to the invention of claim 4, since the end of the double duct is made of ferritic steel, the attenuation of the magnetic field at the end of the electromagnetic pump can be slowed down. Therefore, reverse thrust is reduced, and pump efficiency is expected to improve. In fact, according to the trial calculation, an additional efficiency of about 3% can be expected by additionally installing the ferrite duct at the end.

According to the invention of claim 5, it is possible to easily realize the slow attenuation of the magnetic field at the end of the electromagnetic pump by the magnetic material.

[Brief description of drawings]

FIG. 1 is a lateral cross-sectional view of a main part of a first embodiment of an electromagnetic pump according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a characteristic diagram showing the relationship between the electrical resistivity ratio and the alumina content of the high electrical composite material according to the first embodiment of the present invention.

FIG. 4 is a characteristic diagram showing the relationship between the alumina content and the bending rupture strength of the test piece according to the first embodiment of the present invention.

FIG. 5 is Inconel 62 in the first embodiment of the present invention.
The characteristic view which shows the electrical resistivity comparison of the test piece which uses 5 as a base material before and after immersion in liquid metal sodium.

FIG. 6 is a characteristic diagram showing a comparison of electrical resistivity before and after immersion of liquid metal sodium in a test piece using SUS316 as a base material in the first embodiment of the present invention.

FIG. 7 is a characteristic diagram showing a relationship between duct resistivity and pump efficiency in the first embodiment of the present invention.

FIG. 8 is an enlarged view of a main part of the second embodiment of the present invention.

FIG. 9 is a vertical sectional view of a fourth embodiment of the present invention.

FIG. 10 is a cross-sectional view of another embodiment of the present invention.

FIG. 11 is a partially cutaway perspective view showing a general configuration of an electromagnetic pump.

[Explanation of symbols]

 1, 21, 31 Electromagnetic pump 2 Conductive fluid (Liquid metal sodium) 3 Outer duct 3c Welded portion 4 Inner duct 5 Double duct 6 Annulus flow path 7 Outer laminated core 8 Gap 9 Slot 10 Outer stator coil 11 Inner laminated iron core 12 Fluid Inlet 13 Fluid Outlet 14 Casing 15 Inner Stator Coil 16 Inlet Piping 17 Inlet Diffuser 18 Outlet Piping 19 Outlet Diffuser 22 Gradient Function Material 23 Magnetic Piece

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takeshi Shimizu Inventor, Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa 1st, Toshiba Research and Development Center (72) Inventor Hidemitsu Matsuzawa, 8 Shinsugita-cho, Isogo-ku, Yokohama, Kanagawa Address Stock Company Toshiba Yokohama Office

Claims (5)

[Claims] 1. A double duct for flowing a conductive fluid in an annular flow passage defined by an outer duct and an inner duct contained therein, and a double duct disposed inside the inner duct and outside the outer duct. Electromagnetic pump having inner and outer laminated cores and a stator coil housed in a slot formed on the duct side of at least one of the inner and outer laminated cores to drive the conductive fluid by a traveling magnetic field formed In the above, the double duct is formed of a particle-dispersed composite material in which particles of either a metal oxide or a metal nitride are added to a non-magnetic matrix base metal whose main component is austenitic stainless steel or nickel. An electromagnetic pump characterized in that. 2. The electromagnetic pump according to claim 1, wherein the particle-dispersed composite material is a powder of austenitic stainless steel or a non-magnetic alloy containing nickel as a main component, and either a metal oxide or a metal nitride. An electromagnetic pump formed by adding and mixing powder particles and sintering the mixture by a hot isostatic pressing method. 3. The electromagnetic pump according to claim 1 or 2, wherein the powder particles of either metal oxide or metal nitride are alumina particles. 4. A double duct for flowing a conductive fluid in an annular flow passage defined by an outer duct and an inner duct contained therein, and a double duct disposed inside the inner duct and outside the outer duct. Electromagnetic pump having inner and outer laminated cores and a stator coil housed in a slot formed on the duct side of at least one of the inner and outer laminated cores to drive the conductive fluid by a traveling magnetic field formed In the above, the both ends of the double duct projecting axially outward more than the axial ends of at least one of the inner and outer laminated iron cores,
An electromagnetic pump formed by a magnetic material of ferritic stainless steel or ferritic chromium alloy steel. 5. A double duct for flowing a conductive fluid in an annular flow passage defined by an outer duct and an inner duct contained therein, and a double duct arranged inside the inner duct and outside the outer duct. Electromagnetic pump having inner and outer laminated cores and a stator coil housed in a slot formed on the duct side of at least one of the inner and outer laminated cores to drive the conductive fluid by a traveling magnetic field formed In the electromagnetic pump, magnetic materials are attached to the outer circumferences of both end portions of the outer duct projecting outward in the axial direction from axial ends of at least one of the inner and outer laminated iron cores.