JPH05260719A - Electromagnetic pump - Google Patents

Abstract

PURPOSE:To improve an efficiency and reliability of an electromagnetic pump, by making the effective sinking of the heat generated in its stator coil possible. CONSTITUTION:In an electromagnetic pump, a double duct comprising an outside duct 3 and an inside duct 4 between which a passage 5 is formed to make a conductive fluid 2 flow, a plurality of laminar core blocks 7 provided on the outer periphery of the double duct, and a stator coil 9 wound around the slots of the laminar core blocks 7 by which a progressive magnetic field is generated in the passage 5 filled with the conductive fluid 2, are provided. In the electromagnetic pump, the double duct is formed in the shape of a cylinder, and the shapes of the inner surfaces of the laminar core blocks 7 are so formed that their curvatures coincide with the curvature of the outer peripheral surface of the double duct, respectively.

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. Regarding pumps.

[0002]

2. Description of the Related Art In a three-phase induction type electromagnetic pump, three-phase AC windings are arranged so as to be distributed in the order of phases in the direction of flow of the electromagnetic pump, and a three-phase AC current is passed through the three-phase AC windings. Then, a traveling magnetic field is generated in the direction of this current flow. When this traveling magnetic field is made to pass through the duct in which the conductive fluid is present, a voltage is induced in the conductive fluid by Fleming's right-hand rule, which causes an induced current. 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 torque in the induction motor,
It is the same as the thrust in a linear motor.

This three-phase induction type electromagnetic pump is roughly classified into two types, 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 is
The ALIP (Ann
It has been widely used in recent years because it is called a regular linear induction pump) and has a highly reliable and safe duct structure.

FIG. 6 shows the basic structure of the ALIP. This electromagnetic pump 1 has an outer duct 3 for flowing a conductive fluid 2 such as liquid metal sodium, which is indicated by an arrow.
The concentric double tube structure of the inner duct 4 forms the annulus flow path 5. Further, in order to form a magnetic circuit of an AC magnetic field in the stator, a laminated core block 7 in which electric iron plates having slots 6 are stacked in the circumferential direction has a gap 8 in the circumferential direction outside the outer duct 3. Multiple are arranged. In this case, the laminated core block 7 has a laminated surface facing the outer duct 3 and is radially provided so that the slots 6 are located inside.

Further, a ring-shaped stator coil 9 is wound in the slot 6, and a large number of the stator coils 9 are arranged in the axial direction and connected so that a three-phase alternating current produces a traveling magnetic field. There is. An inner iron core 10 for forming a magnetic circuit is housed inside the inner duct 4. As a result, the conductive fluid 2 enters the electromagnetic pump 1 through the fluid inlet 11 and flows through the annulus flow path 5 so that a voltage is induced and the conductive fluid 2 is delivered from the fluid outlet 12. It should be noted that the laminated core block 7 and the stator coil 9 are cooled by a circulating gas by an external fan (not shown).

In recent years, in order to increase the capacity of the electromagnetic pump 1 and eliminate restrictions on the installation location to improve the design of a plant using the electromagnetic pump 1, it is desired to downsize the electromagnetic pump 1, and the electromagnetic pump 1 is also required. In order to save the installation space and to bring out the advantages of the entire plant, it is required to operate the electromagnetic pump 1 by immersing it in the conductive fluid 2.

In order to meet these demands, it is necessary to cool the stator coil 9 not by forced gas cooling as described above but by cooling the outer surface of the jacket without circulating the cooling gas. There are many advantages of.

That is, since the space for circulating the cooling gas can be omitted, the outer diameter can be reduced. Further, since an external device such as a fan and a pipe for circulating the cooling gas is not required, the entire device of the electromagnetic pump 1 becomes compact and the immersion type structure and the condition for maintenance become good. Furthermore, when the outer surface of the jacket is cooled,
In the case of a large-capacity machine to some extent, the stator coil can be arranged also in the inner iron core 10, so that the output of the electromagnetic pump 1 can be further increased and the size can be further reduced.

Further, when the outer surface of the jacket is cooled, the heat loss generated in the stator coil 9 is transmitted from the stator coil 9 to the laminated core block 7, and from the laminated core block 7, the outer duct 3 and the casing (not shown). To the inside of the conductive fluid 2. Therefore, it is necessary to minimize the thermal resistance from the stator coil 9 to the conductive fluid 2, and it is therefore desirable that these structures contact each other during operation.

[0010]

However, in order to increase the output of the electromagnetic pump 1, it is necessary to flow a large amount of current through the stator coil 9. For this purpose, it is effective to minimize the temperature rise of the stator coil 9. Further, since the conductive fluid 2 generally uses a high temperature, the electromagnetic pump 1 immersed in the conductive fluid 2 is operated in a high temperature state.

From the viewpoint of the efficiency of the electromagnetic pump 1, heat generated by the current in the stator coil 9 is lost, so that when the temperature of the stator coil 9 becomes high, copper or the like which is usually used as a coil conductor is used. The electric resistance of the conductive material increases, the loss increases for the same load current, and the efficiency decreases. Therefore, it is important to reduce the temperature rise of the coil.

Furthermore, the heat generated in the stator coil 9 is
It is necessary to let the liquid metal sodium flowing through the duct through the laminated core block 7 escape to the laminated core block 7.
Is a block in which flat plates are piled up, and the tip surface has a stepped shape, and point contact with the outer circumference of the duct makes it difficult for heat to escape.

On the other hand, the electromagnetic pump 1 has a loss due to an induced current flowing through the flesh portions of the outer duct 3 and the inner duct 4. In the electromagnetic pump 1, the conductive fluid 2 functions as a boundary in terms of reliability. Therefore, since these ducts were made of metal such as stainless steel, this loss significantly reduced the efficiency of the electromagnetic pump 1.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an electromagnetic pump capable of efficiently dissipating heat generated in a stator coil and improving pump efficiency and reliability. And

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an electromagnetic pump according to the present invention comprises a double duct having an outer duct and an inner duct and a flow path for flowing a conductive fluid formed between these ducts. A duct, a plurality of laminated core blocks arranged on the outer periphery of the double duct, and a stator coil that is wound around the slots of the laminated core block and creates a traveling magnetic field in the flow path in which the conductive fluid is present. In the provided electromagnetic pump, the double duct is formed in a cylindrical shape, and the inner surface of the laminated core block is formed in a shape matching the curvature of the outer peripheral surface of the double duct.

An electromagnetic pump according to another aspect of the present invention is a double duct including an outer duct and an inner duct, in which a flow path for flowing a conductive fluid is formed, and the double duct is disposed on the outer circumference of the double duct. In the electromagnetic pump comprising a plurality of laminated core blocks, and a stator coil wound in a slot of the laminated core block to create a traveling magnetic field in the flow path in which the conductive fluid exists, at least the double duct The outer surface of the outer duct is formed in a polygonal shape corresponding to the number of the laminated core blocks.

[0017]

In the present invention having the above-mentioned structure, the inner surface of the laminated core block is formed in a shape that matches the curvature of the outer peripheral surface of the double duct, or at least the outer duct of the double duct is the number of laminated core blocks. Since it is formed in a polygonal shape corresponding to, the contact thermal resistance between the laminated core block and the double duct is significantly reduced, and the heat generated in the stator coil flows through the laminated core block and the double duct in the double duct. Efficiently escapes to conductive fluid. Therefore,
The temperature rise of the stator coil is reduced and the pump efficiency can be improved.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show a first embodiment of an electromagnetic pump according to the present invention. It should be noted that the same or corresponding portions as those of the conventional configuration will be described with the same reference numerals as those in FIG.

As shown in FIG. 2, the electromagnetic pump 20 is immersed in a conductive fluid 2 such as liquid metal sodium, and six laminated core blocks 7 having slots 6 are circled in a metal casing 21. They are arranged at equal intervals in the circumferential direction. A plurality of ring-shaped stator coils 9 are wound around the slots 6 of the laminated core block 7 in the axial direction,
The stator coil 9 is connected so that a three-phase alternating current produces a traveling magnetic field.

A double cylindrical duct is formed by the outer duct 3 and the inner duct 4 in the laminated core block 7, and an annulus passage 5 for flowing the conductive fluid 2 is formed between these ducts. An inner core 10 for forming a magnetic circuit is provided inside the inner duct 4.

The lower side of the annulus channel 5 shown in FIG. 2 is a fluid inlet 11 into which the conductive fluid 2 flows, and the upper side is a fluid outlet 1.
2, a fluid inlet 11 is formed by a casing 21, and a fluid outlet 12 is formed by a metal pipe 22. The liquid surface of the conductive fluid 2 is located above the stator coil 9.

Further, as shown in FIG. 1, the inner surface of each of the six laminated core blocks 7 is machined to form an arcuate contact surface that matches the curvature of the outer peripheral surface of the outer duct 3 of the double cylindrical duct. 7a.

Next, the operation of this embodiment will be described.

In the electromagnetic pump 20 of this embodiment, since the inner surfaces of the six laminated core blocks 7 are formed into the arc-shaped contact surfaces 7a which match the curvature of the outer peripheral surface of the outer duct 3, the laminated core blocks 7 and the outer side are not formed. The contact area with the duct 3 is increased, and the heat generated in the stator coil 9 can be efficiently released to the conductive fluid 2 flowing in the annulus passage 5.

As a result, the temperature of the stator coil 9 is lowered and the electric resistance of the coil is reduced, so that the amount of heat generation is reduced. Therefore, the pump loss is reduced, the pump efficiency is improved, and the service life is extended.

In this embodiment, the inner surface of the laminated core block 7 is machined according to the curvature of the outer peripheral surface of the outer duct 3. However, in addition to this, the individual steel plates constituting the laminated core block 7 have a predetermined curvature in advance. After processing, laminated core block 7
It is also possible to assemble them and arrange them so as to contact the outside of the outer duct 3.

FIG. 3 shows a second embodiment of the electromagnetic pump according to the present invention. The same members as those in the first embodiment will be described with the same reference numerals. In this electromagnetic pump 30, the inner surface of the laminated iron core block 7 formed in a step-like shape has heat resistance such as SiC or BeO having a high thermal conductivity and a high insulation resistance so as to match the curvature of the outer peripheral surface of the outer duct 3. The material 23 is coated, and the binding material 2 is applied to the outer surface of the laminated core block 7 according to the inner surface shape of the casing 21.
3 is coated.

Therefore, in the electromagnetic pump 30, since the laminated core block 7 is in contact with the outer duct 3 and the casing 21, the heat generated in the stator coil 9 causes the conductive fluid 2 flowing in the annulus flow path 5, and Each is efficiently discharged to the conductive fluid 2 flowing outside the casing 21. The rest of the configuration and operation are the same as in the first embodiment, so description thereof will be omitted.

FIG. 4 shows a third embodiment of the electromagnetic pump according to the present invention. Members which are the same as or correspond to those of the first embodiment will be designated by the same reference numerals. In the electromagnetic pump 40 of this embodiment, the double duct shape formed by the outer duct 3 and the inner duct 4 is hexagonal with respect to the six laminated iron core blocks 7, and the front end surface of the laminated iron core block 7 and the outer duct 3 are connected to each other. The contact surface of is flat.

Next, the operation of this embodiment will be described.

In the electromagnetic pump 40 of this embodiment, since the contact area between the laminated core block 7 and the outer duct 3 is increased by making the double duct shape hexagonal, the heat generated by the stator coil 9 is generated by the annulus passage. Conductive fluid 2 flowing through 5
Can be released efficiently. As a result, the temperature of the stator coil 9 decreases and the electric resistance of the stator coil 9 decreases, so the amount of heat generation decreases. As a result, pump losses are reduced and efficiency can be improved. The rest of the configuration and operation are the same as in the first embodiment, so description thereof will be omitted.

Although the double duct formed by the outer duct 3 and the inner duct 4 is formed in a hexagonal shape in the above embodiment, the present invention is not limited to this and the same effect can be obtained by forming it in another polygonal shape. Be done.

FIG. 5 shows a fourth embodiment of the electromagnetic pump according to the present invention, and the same or corresponding members as those in the first embodiment will be designated by the same reference numerals. In the electromagnetic pump 50 of this embodiment, the outer surface of the outer duct 3 is hexagonal with respect to the six laminated iron core blocks 7, the inner surface of the outer duct 3 is circular, and the inner duct 4 is cylindrical. The contact surface between the tip end surface of the iron core block 7 and the outer surface of the outer duct 3 is a flat surface. In this embodiment, the same effect as that of the third embodiment can be obtained. The rest of the configuration and operation are the same as in the first embodiment, so description thereof will be omitted.

[0035]

As described above, according to the electromagnetic pump of the present invention, the inner surface of the laminated core block is formed into a shape that matches the curvature of the outer peripheral surface of the double duct, or at least the double duct. Since the outer surface of the outer duct is formed in a polygonal shape corresponding to the number of laminated core blocks, the heat generated in the stator coil can be efficiently dissipated, and the temperature rise of the stator coil can be suppressed. For this reason,
Since the heat generation of the stator coil can be made larger than in the conventional case, a larger flow rate can be flowed. As a result, the efficiency of the pump is improved, and it is possible to provide a more compact and large-capacity electromagnetic pump.

[Brief description of drawings]

FIG. 1 is an enlarged view of essential parts showing a first embodiment of an electromagnetic pump according to the present invention.

FIG. 2 is a vertical cross-sectional view of FIG.

FIG. 3 is an enlarged view of a main part showing a second embodiment of the electromagnetic pump according to the present invention.

FIG. 4 is an enlarged view of an essential part showing a third embodiment of the electromagnetic pump according to the present invention.

FIG. 5 is an enlarged view of an essential part showing a fourth embodiment of the electromagnetic pump according to the present invention.

FIG. 6 is a partially cutaway perspective view showing a conventional electromagnetic pump.

[Explanation of symbols]

 2 conductive fluid 3 outer duct 4 inner duct 5 annulus flow path 6 slot 7 laminated core block 7a arcuate contact surface 9 stator coil 10 inner iron core 20 electromagnetic pump 21 casing 22 pipe 23 binding material

Claims (2)

[Claims] 1. A double duct having an outer duct and an inner duct, in which a flow path for a conductive fluid is formed between the ducts, a plurality of laminated core blocks arranged on the outer periphery of the double duct, and In an electromagnetic pump provided with a stator coil that is wound around a slot of a laminated core block and creates a traveling magnetic field in the flow path where the conductive fluid exists, the double duct is formed in a cylindrical shape, and the laminated core An electromagnetic pump, wherein the inner surface of the block is formed in a shape that matches the curvature of the outer peripheral surface of the double duct. 2. A double duct comprising an outer duct and an inner duct, in which a flow path for conducting a conductive fluid is formed, a plurality of laminated core blocks arranged on the outer periphery of the double duct, and In an electromagnetic pump provided with a stator coil which is wound around a slot of a laminated core block and creates a traveling magnetic field in the flow path in which the conductive fluid exists, the laminated core block has at least the outer surface of the outer duct of the double duct. An electromagnetic pump characterized by being formed in a polygonal shape corresponding to the number of.