JPH0789734B2 - Faraday type electromagnetic pump with annular passage - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electromagnetic pump capable of conveying a conductive fluid such as liquid sodium, and more particularly to a Faraday type electromagnetic pump.

[Prior Art] Conventionally, when carrying a conductive fluid such as liquid sodium,
An electromagnetic pump is used. This electromagnetic pump is roughly classified into two types, an induction type electromagnetic pump and a Faraday type electromagnetic pump.

The former induction type electromagnetic pump does not require an electrode like the Faraday type because it sends the fluid by the interaction between the induced current generated in the conductive fluid by the moving magnetic field and the moving magnetic field. It is simple. However, it is difficult to analyze the output characteristics and difficult to control the flow rate.

On the other hand, the Faraday type electromagnetic pump allows magnetic flux to pass through in the vertical direction of a fluid passage of rectangular cross section or circular cross section made of stainless steel or the like, and attaches electrodes to the left and right side walls of the fluid passage to pass current. That is, since a force F is applied to the conductive fluid in the passage in a direction according to Fleming's left-hand rule to propel the fluid, output analysis is very simple and easy, and flow rate control is easy.

However, in the above-mentioned Faraday-type electromagnetic pump that uses a fluid passage having a rectangular cross section, the passage has a rectangular cross section, so that there are problems in mechanical strength and flow resistance of the conductive fluid.

Also, in the case of using a fluid passage with a circular cross section,
Since the distance between the electrodes varies depending on the location, a local eddy current or pulsation of the conductive fluid occurs, which makes output analysis difficult.
In order to pass a sufficiently large electric current to the conductive fluid, it is necessary to take a large contact surface between the electrode and the passage. For this reason, it is necessary to bond the electrode and the passage with a considerably long arcuate surface, and there is a drawback that the bonding work is more difficult.

Therefore, in order to solve such a problem, there has been proposed one in which a space formed between two concentrically arranged circular tubes having different diameters is used as a passage for a conductive fluid (JP-A-51-51).
111906 publication). That is, a space formed between two circular pipes having different diameters arranged concentrically is partitioned by electrodes to form a plurality of passages for the conductive fluid. And
A magnetic pole of a magnetic circuit is arranged on the outer peripheral side of the fluid passage, a magnetic flux is passed through the passage in the radial direction of the circular pipe, and a current is passed between the electrodes in the circumferential direction of the fluid passage.

In this electromagnetic pump, since the fluid passage is basically circular, the above-mentioned problems are solved.

[Problems to be Solved by the Invention] The circular tube forming the fluid passage is made of stainless steel having a resistance to a conductive fluid such as liquid sodium. On the other hand, copper is used for the electrodes because a large current flows through them. However, in the conventional electromagnetic pump, since the space between the circular tubes made of stainless steel is partitioned by the electrodes,
It is necessary to join a circular tube made of stainless steel and an electrode made of copper.

However, it is difficult to directly join Slenteth and copper by welding means. When joining these, generally, the means of welding through nickel or brazing is taken. However, in the case of a fast breeder reactor in which a Faraday-type electromagnetic pump is used, the liquid sodium that is a fluid reaches 600 ° C., and therefore these joining means cannot be used.

Therefore, in view of the above-mentioned problems in the prior art, the present invention allows Faraday to flow a current evenly in the circumferential direction of a circular pipe in a fluid passing through a fluid passage without requiring welding of stainless steel and copper. Type electromagnetic pump.

[Means for Solving the Problems] That is, the above-mentioned object of the present invention is to divide the space between a plurality of concentrically arranged circular tubes 10 and 11 having different diameters into a plurality of sections in the circumferential direction so as to improve conductivity. The fluid passages 13a, 13b ... through which the fluid can flow in the axial direction of the circular tubes 10, 11 and the fluid electrode portions 14a, 14b ... in which the conductive fluid is prevented from flowing in the axial direction of the circular tubes are alternately arranged. The fluid passages 13a, 13b ... And the fluid electrode portions 14a, 14b ...
And the conductive fluid is filled with the fluid electrode parts 14a, 14b ...
Electrodes 15a, 15a having different polarities on the peripheral wall portions of the circular tubes 10, 11 ...
Are alternately arranged in the circumferential direction and connected, and the fluid passages 13a and 13b are connected.
It is achieved by a Faraday type electromagnetic pump having an annular passage, characterized in that the magnetic poles facing each other in the magnetic circuit are alternately arranged in the circumferential direction on the inner and outer peripheral sides of the circular tubes 10 and 11 as shown in FIG.

[Operation] In the Faraday type electromagnetic pump according to the present invention, the space between the concentric circular pipes 10 and 11 of different diameters is divided into a plurality of circumferentially divided fluid passages 13a. , 13b
... and the fluid electrode portions 14a, 14b ... Are filled with a conductive fluid, and electrodes 15a, 15a having different polarities are alternately arranged in the circumferential direction on the peripheral wall portions of the circular tubes 10, 11 of the fluid electrode portions 14a, 14b. Since they are arranged and connected, a current flows in the conductive fluid inside the fluid passages 13a, 13b ... In the circumferential direction of the circular tubes 10, 11 through the electrodes 15a, 15b ... And the fluid electrode portions 14a, 14b on both sides. . At this time,
The directions of the currents in the adjacent fluid passages 13a, 13b ... Are opposite.

On the other hand, since the opposing magnetic poles of the magnetic circuit are arranged so as to be alternately opposite magnetic poles in the circumferential direction on the inner and outer peripheral sides of the circular tubes 10 and 11 of the fluid passages 13a, 13b ... A magnetic flux passes through the fluid in the radial direction of the circular pipe. At this time, the directions of the magnetic fluxes in the adjacent fluid passages 13a, 13b, ... Are alternately opposite. Therefore, the thrust in the axial direction of the circular pipe is applied to the conductive fluid in the fluid passages 13a, 13b ... And the direction of the thrust is
All fluid passages 13a, 13b ... Have the same direction.

Then, the electrodes 15a, 15a ... May be electrically connected to the peripheral wall portions of the circular tubes 10, 11 of the fluid electrode portions 14a, 14b.
Since it is not necessary to partition the space between the circular tubes 10 and 11 with a, 15b, ..., The circular tubes 10 and 11 can be partitioned with a structural material other than the electrode material, that is, the same material as the circular tube. For this reason, direct welding is possible and a high-strength flow path can be formed.

EXAMPLES Examples of the present invention will be described below with reference to the accompanying drawings.

Referring to FIG. 1, the Faraday type electromagnetic pump according to the present invention has circular pipes 10 and 11 which are concentrically combined and which are made of two stainless steel pipes having circular cross sections with different diameters. A ring-shaped space formed between them is partitioned in the circumferential direction. In the embodiment shown in FIG. 1, the annular space is circumferentially divided into eight by the partition wall 12, and the divided portions are alternately formed with the fluid passages 13a, 13b ... And the fluid electrode portion.
14a, 14b ... and so on.

The fluid passages 13a, 13b, ... Are filled with a conductive fluid such as liquid metal sodium, and the fluid electrode portions 14a, 1b.
4b ... is also filled with a conductive fluid such as liquid metal sodium.

A circular tube forming the outer peripheral wall of the fluid electrode portions 14a, 14b, 14c, 14d
Four electrodes 15a, 15b ... Made of a material having excellent conductivity such as copper are connected to the surface of each of 10 and these four electrodes 15a, 1 are connected.
5b ... have different polarities alternately in the circumferential direction. That is, the two electrodes 15b and 15d are connected to the positive output terminal of the DC power source, which is not shown in the figure as a positive electrode, and the other two.
The two electrodes 15a and 15c are connected as negative electrodes to the negative output terminal of the DC power supply.

As shown in FIG. 1, the two circular tubes 10, 11 are
Inner yokes 16 and 16 'and outer yokes 17 and 17' made of yokes are provided inside and outside the annular space formed by, respectively, and a coil 18 is provided in a part of these outer yokes 17 and 17 '. , 18 'are wound to generate a magnetomotive force. Further, the inner yoke 16 and the outer yoke 17, and the inner yoke 16 'and the outer yoke 17' are respectively arranged in combination so as to form two magnetic circuits. Further, the inner yokes 16 and 16 'and the outer yokes 17 and 17' face each other with the annular space formed by the two circular pipes 10 and 11 sandwiched between the inner peripheral side and the outer peripheral side, This facing portion is a portion of the fluid passages 13a, 13b ... In the annular space.

Further, FIG. 2 shows an axial cross section of the Faraday type electromagnetic pump shown in FIG. The both ends of the circular tube 11 having a small diameter are gradually thinned at their tips, and are processed so as not to disturb the flow of fluid. A circular tube with a small diameter
11 is fixed via a spacer 19 on the central axis of a circular tube 10 having a large diameter.

Next, the operation of this Faraday type electromagnetic pump will be described. First, the fluid electrode portions 14a, 14b, ... Formed between the two circular tubes 10, 11 and the fluid passageway formed between them.
13a, 13b ... Are filled with the conductive fluid to be transported. On the other hand, a current is supplied from a power source to the coils 18, 18 'wound around a part of the pair of outer yokes 17, 17' to generate a magnetomotive force NI in the direction indicated by the arrow in FIG. This magnetomotive force NI is generated by the outer yokes 17 and 17 'and the inner yoke 1
A magnetic field B is generated in the four fluid passages 13a, 13b ... Inserted between them via 6 and 16 '. The magnetic flux of the magnetic field B passes from the inner circumference to the outer circumference of the circular pipes 10 and 11 in the fluid passages 13a and 13c, and the circular pipe 10 in the other fluid passages 13b and 13d.
Pass from the outer circumference to the inner circumference of 11. That is, the fluid passage
The direction in which the magnetic flux of the magnetic field B passes through the conductive fluid in 13a, 13b, ... Alternately in the radial direction of the circular tubes 10, 11.

Further, of the electrodes, a positive voltage is applied to the two electrodes 15b and 15d, while a negative voltage is applied to the other two electrodes 15a and 15c.
At this time, the current I flows from the positive currents 15b and 15d through the conductive fluid inside the liquid electrode portions 14b and 14d, and the conductive fluid inside the fluid passages 13a, 13b ... It flows in the circumferential direction and flows from the conductive fluid in the other fluid electrode portion 14a, 14c to the negative electrodes 15a, 15c. That is, the directions of the currents flowing through the conductive fluids in the adjacent fluid passages 13a, 13b ... Are opposite to each other.

At this time, a thrust F according to the so-called Faraday's left-hand rule is generated in the conductive fluids in the four fluid passages that conduct the current. The direction of this thrust F is the same as the direction of the current I flowing through the fluid passages 13a and 13b.
13a, 13b ... are opposite to each other, but the directions of the magnetic flux passing therethrough are also opposite to each other.
The conductive fluids in 13a, 13b, ...
Receive.

Thus, in the Faraday type electromagnetic pump of the above embodiment,
The fluid passages 13a, 13b forming the pump are provided with two circular pipes 10,
Since it can be formed in the space between 11, the mechanical strength can be made excellent. Further, the annular space formed by the two circular tubes 10 and 11 is divided into a plurality of parts on the circumference, and the fluid passages 13a, 13b, ...
By providing a, 14b ... and flowing a current in the conductive fluid in the fluid passages 13a, 13b ... in the circumferential direction of the circular pipes 10, 11, heat generation due to uneven distribution of current or local concentration Turbulence and eddy current due to non-uniformity hardly occur. Moreover, the partition wall 12
Unlike the electrode material, the same material as the circular tubes 10 and 11 can be used, so that welding can be performed easily. For example, without the difficult work of joining stainless steel and copper by Ni welding,
It is relatively easy to manufacture and has high mechanical and thermal strength.

FIG. 3 shows a modification of the fluid electrode portion 14a of the Faraday type electromagnetic pump shown in FIG. That is, here, the through hole 2 is formed in a part of the partition wall 12 forming the fluid electrode portion 14a.
Multiple 0s are provided. Through these through holes 20, a part of the conductive fluid flowing in the adjacent passages 13d and 13a flows into the inside of the fluid electrode portion 14a, and this is used as a conductor of the fluid electrode portion 14a. Further, in this modification, the gas generated in the conductive fluid introduced into the fluid electrode portion 14a can also be extracted to the outside through the through hole 20, and in particular, a high speed for transporting liquid sodium reaching 600 ° C. It is advantageous as a Faraday type electromagnetic pump for a breeder reactor.

Further, as indicated by the dotted line in the figure, the fluid electrode portion is
The space forming 14a is partitioned by the partition wall 21 in the axial direction of the circular tube 10 at regular intervals, whereby the conductive fluid in the fluid electrode portion 14a receives a thrust force and the circular tubes 10, 1
It is prevented from moving in the axial direction of 1.

FIG. 4 shows another modification of the fluid electrode portion 14a of the Faraday type electromagnetic pump shown in FIG. In this modification, in order to alleviate the thermal expansion which becomes a problem in use at high temperature, one stainless plate 12 'for forming the space of the liquid electrode portion 14a is processed into a "U" shape, This is joined to the circular tubes 10 and 11 forming the inner and outer walls. Further, as is the case with FIGS. 1 and 3, a plurality of slits 22 for relaxing thermal stress are formed in the electrode 15b joined to the outer wall of the fluid electrode portion 14a.

Another embodiment of the Faraday type electromagnetic pump according to the present invention is shown in FIGS. In this embodiment, the fifth
As shown in the figure, the four electrodes 15a, 15b, 15c, 15d are formed on the outer wall of the circular tube 10 forming an annular space, and the fluid electrode portions 14a, 1
4b, 14c, in the portion corresponding to 14d, while being bonded on the circumference, electrodes 151a, 151b, 151c, in the axial direction of the circular tube 10 as well.
151d and 152a, 152b, 152c, 152d and the like (however, only the electrodes 151a and 151b are shown in the drawing) are arranged. These electrodes 151a, 151b, 151c, 151d and 152a, 15
2b, 152c, 152d, etc. are arranged so that their polarities are different from those of the two adjacent to each other in the axial direction of the circular tube 10. For example, with respect to the positive electrode 15a, the electrode 151a is a negative electrode and the electrode 152a is a positive electrode. Further, the axial distance d between the electrode 15a and the electrode 151a is arranged to be larger than the circumferential distance D between the fluid electrode portions 14a and 14b, and further, the electrodes 15a and 15 / a. There is an insulating plate 19 between them. Therefore, the current does not flow in the axial direction of the circular tubes 10 and 11, but only in the circumferential direction.

Further, FIG. 6 shows the magnetic flux generator of the Faraday type electromagnetic pump of FIG. The inner yoke 16 of FIG. 1,
Inner yoke 16 as well as outer yoke 17 and coil 18.
A plurality of magnetic circuits composed of 1, the outer yoke 171, and the coil 181 are arranged on the circumference of the circular tube 10 and at a predetermined distance in the axial direction thereof, which is indicated by an arrow in FIG. The magnetic field B is formed in such a direction.

FIG. 7 shows a modification of the magnetic flux generator of the Faraday type electromagnetic pump shown in FIG. Multiple inner yokes 16
1 ', outer yoke 171', and coil 181 'are alternately circular tubes 10, 1
1 is sandwiched and coupled to form a magnetic field that alternately changes from the inside to the outside and from the outside to the inside in the axial direction of the circular tubes 10 and 11.

In this embodiment, it is possible to arrange a plurality of magnetic circuits in the axial direction of the circular tube 10, and the thrust of the conductive fluid is large,
It is possible to make a Faraday type electromagnetic pump having a large carrying force.

[Effects of the Invention] As is apparent from the above description, according to the present invention, heat generation due to uneven distribution of current or local concentration can be achieved without joining copper as an electrode material and a stainless tube as a circular tube material. It is possible to provide a Faraday type electromagnetic pump that does not generate turbulence or vortex flow due to non-uniform thrust.

[Brief description of drawings]

FIG. 1 is a perspective view including a cross section showing the structure of a Faraday type electromagnetic pump according to an embodiment of the present invention, and FIG.
It is sectional drawing of the Faraday type electromagnetic pump shown in the figure in the axial direction, FIGS. 3 and 4 are views showing a modified example of the fluid electrode part of FIG. 1, and FIGS. FIG. 7 is a perspective view and a cross-sectional view showing the structure of a Faraday type electromagnetic pump according to another embodiment of the invention, and FIG. 7 is a cross-sectional view showing a modification of the magnetic flux generator of FIG. 10, 11 …… Circular pipe, 12 …… Differential wall, 13a, 13b, 13c, 13d ……
Fluid passage, 14a, 14b, 14c, 14d ... Fluid electrode section, 15a, 1
5b, 15c, 15d …… electrodes, 16,16 ′ …… inner yoke, 17,
17 '... outer yoke, 18, 18' ... coil

Claims (1)

[Claims] 1. A counter electrode (15a), (1) which sandwiches a passage through which a conductive fluid passes and which supplies an electric current to the conductive fluid passing through the passage.
5a) ..., and a Faraday type electromagnetic pump including a magnetic circuit for passing a magnetic flux through a conductive fluid in a direction perpendicular to the current, a plurality of circular tubes (10) having different diameters, which are concentrically arranged,
The space between (11) is divided into a plurality of parts in the circumferential direction, and a conductive fluid is formed by fluid passages (13a), (13b), etc., through which the conductive fluid can flow in the axial direction of the circular tubes (10), (11). Fluid electrodes (14a), (14b), ..., in which fluid is prevented from flowing in the axial direction of the circular pipe, are alternately provided, and these fluid passages (13a), (13b), ... And fluid electrode (14a). , (14b), ... And filled with a conductive fluid, and the circular tubes (10) of the fluid electrode parts (14a), (14b) ,.
Electrodes (15a) and (15a) with different polarities on the peripheral wall of (11)
... are alternately connected in the circumferential direction, and fluid passages (13a), (13
b) Faraday-type electromagnetic wave having an annular passage, characterized in that the opposite magnetic poles of the magnetic circuit are alternately arranged in the circumferential direction on the inner and outer peripheral sides of the circular tubes (10) and (11) so as to be opposite magnetic poles. pump.