JPH06189521A - Immersed electromagnetic pump - Google Patents

Abstract

PURPOSE:To provide large capacity and compactness for a pump by increasing the current in a stator coil. CONSTITUTION:A plurality of stacked iron core blocks having slots are arranged on the periphery of the outer pipe being provided coaxially, forming an annulus passage for letting conductive fluid flow outside of an inner pipe. Many circular stator coils for letting three-phase AC currents flow for making progressive magnetic fields in the annulus passage are arranged inside the slot of this stacked iron core block, and the stacked iron core block is fixed to a tubular iron core frame, and a stator coil and a stacked iron core block are fastened at large with circular press plates 18 provided at both ends in the axial direction of this iron core frame 17 so as to unit them with the iron core frame 17, and the united object is attached inside the tubular casing 19, and as the material of the stacked iron core block and the iron core frame 17, the one smaller than or practically the same as the outer pipe in thermal expansion coefficient is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an immersion type electromagnetic pump which is immersed in a conductive fluid and transports the conductive fluid by an electromagnetic induction action.

[0002]

2. Description of the Related Art Generally, in a three-phase AC induction type electromagnetic pump, three-phase AC windings are arranged in the flow direction of the electromagnetic pump in the order of each phase, and the three-phase AC windings are connected to each other. Flowing, a traveling magnetic field is generated in the direction of the flow of the conductive fluid.
When this progressive magnetic field is made to pass through a duct containing a conductive fluid, Fleming's right-hand rule induces a voltage in the conductive fluid, which causes an induced current. Then, the induced current and a part of the component of the traveling magnetic field act to generate an electromagnetic force, which acts as a pump by receiving a force such that the conductive fluid flows. Now, this type of three-phase AC 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. The present invention is
The present invention relates to the annular linear type electromagnetic pump, and its configuration will be described below.

An annular linear electromagnetic pump generally has an ALIP (Annular Line) because of its annular cross section.
ar Induction Pump). This ALI
P is a mainstream pump in recent years because of its highly reliable and safe duct structure. FIG. 4 is a cross-sectional perspective view showing a basic configuration example of a conventional ALIP of this type.

In FIG. 4, the duct is a double cylindrical duct having a double pipe structure in which an inner duct 1 and an outer duct 2 are concentrically arranged, and forms an annulus passage 3 through which a conductive fluid flows. There is.

In the stator, a plurality of laminated iron core blocks 4 in which iron cores having slots are stacked in the circumferential direction in order to form a magnetic circuit of an alternating magnetic field are circumferentially arranged on the outer peripheral side of the outer duct 2. It is arranged. Here, the laminated surface of the laminated core block 4 faces the duct, and the slots are arranged inside so that the entire iron core is radially formed.

Further, an annular stator coil 5 is arranged in the slot of the laminated core block 4. A large number of the stator coils 5 are arranged in the axial direction and are connected so that a three-phase alternating current creates a traveling magnetic field. On the other hand, inside the inner duct 1, a laminated inner core 6 for forming a magnetic circuit is housed. Further, the conductive fluid enters the electromagnetic pump through the fluid inlet 7, the pressure is induced while flowing through the annulus flow path 3, and the conductive fluid exits through the fluid outlet 8. further,
The stator coil 5 is cooled by a gas circulated by a fan provided outside the stator coil 5.

By the way, in recent years, in order to increase the capacity of the electromagnetic pump and make it more compact to save the installation place of the electromagnetic pump and bring out the advantages of the entire plant, the electromagnetic pump is immersed in a conductive fluid. Driving is being strongly demanded.

As a method for satisfying the above requirements, it is necessary to cool the outer surface of the stator coil 5 without circulating the cooling gas, instead of forcibly cooling the stator coil 5 with the gas.

However, in the case of such surface cooling of the jacket, the heat loss generated in the stator coil 5 is transmitted from the stator coil 5 to the iron core, and from the iron core to the duct or frame, so that the conductive fluid It is necessary to let the heat escape inside.

Therefore, it is important to reduce the thermal resistance from the stator coil 5 to the conductive fluid as much as possible, and for that purpose, it is important that these structures are in contact with each other during operation. .

Further, in general, a conductive fluid having a high temperature is often used, so that the electromagnetic pump immersed in the conductive fluid is operated at a high temperature. Electromagnetic pumps are usually assembled at room temperature and are 60 degrees Celsius.
It is operated at various temperatures up to 0 degrees.

Therefore, it is necessary to prevent the stress due to the difference in thermal expansion between the structures at any such temperature and to maintain the contact between the structures.

However, at present, no electromagnetic pump has been realized which can prevent the stress due to the difference in thermal expansion between the structures and can maintain the contact between the structures. is there.

[0014]

As described above, in the conventional electromagnetic pump, the heat generated in the stator coil, which is the heat generating portion, cannot be efficiently released to the conductive fluid, and the capacity is increased. There is a problem that it is difficult to meet the demand for compactness.

An object of the present invention is to provide an extremely reliable immersion type electromagnetic pump capable of increasing the capacity and size by increasing the current flowing through the stator coil.

[0016]

In order to achieve the above object, in the present invention, on the outer circumference of an outer pipe which is concentrically provided with an annulus passage for flowing a conductive fluid outside the inner pipe, A plurality of laminated core blocks having slots are radially arranged, and in the slots of the laminated core block, a large number of annular stator coils for flowing a three-phase alternating current to create a progressive magnetic field in the annulus passage are arranged, The laminated core block is fixed to the cylindrical core frame, and the stator coils and the laminated core block are tightened by the annular pressing plates provided at both ends of the core frame in the axial direction to be integrated with the core frame. The laminated core block and the core frame are made of a material having a thermal expansion coefficient smaller than or almost the same as that of the outer tube.

Here, in particular, the laminated iron core block is provided with a dovetail on the outer peripheral side thereof, and is fitted with a dovetail groove into a cylindrical iron core frame having a dovetail groove on the inner peripheral side relative to the dovetail, and the cotter is attached. It is stuck due to.

Further, the laminated core block is provided with a convex guide on the outer peripheral side thereof, and is fitted by a groove into a cylindrical core frame having a concave groove on the inner peripheral side facing the convex guide. They are fixed together with bolts from the outer circumference of the iron core frame.

[0019]

Therefore, in the immersion type electromagnetic pump of the present invention, when the electromagnetic pump is in operation, the stator coil, which is the largest heat generating portion, becomes the high temperature portion, and the duct in contact with the conductive fluid becomes the low temperature portion, and in between. The laminated iron core block and the iron core frame that perform heat transfer serve as the middle temperature part. The laminated core block and core frame, which have a higher temperature than the duct, are made of a material having a coefficient of thermal expansion smaller than that of the duct. You can almost eliminate it. As a result, it is possible to improve heat transfer between the stator coil and the duct, so that it is possible to increase the capacity and the size of the electromagnetic pump.

[0020]

(Embodiment) The present invention is an electromagnetic pump, in which the heat generated in the stator coil, which is a heat generating portion, is efficiently released to the fluid in order to increase the capacity and the size of the electromagnetic pump. Since the point is to increase as much as possible, it is intended to improve the heat transfer by minimizing the gap between the duct and the iron core during the operation of the electromagnetic pump. An embodiment of the present invention based on the above concept will be described below in detail with reference to the drawings. FIG. 1 is a horizontal cross-sectional view showing a structural example of an immersion type electromagnetic pump according to the present invention, and FIG. 2 is a vertical sectional view showing a structural example of the immersion type electromagnetic pump.

In FIGS. 1 and 2, the duct is a double cylindrical duct having a double pipe structure in which an inner duct 11 and an outer duct 12 are concentrically arranged, and an annulus passage 13 through which a conductive fluid flows is formed. Is forming. Further, in the stator, a plurality of laminated core blocks 14 are circumferentially arranged on the outer peripheral side of the outer duct 12 in order to form a magnetic circuit of an AC magnetic field.

Further, an annular stator coil 15 is arranged in the slot of the laminated core block 14.
A large number of the stator coils 15 are arranged in the axial direction and are connected so that a three-phase alternating current creates a traveling magnetic field. Further, inside the inner duct 11, a laminated inner iron core 16 for forming a magnetic circuit is housed.

The laminated iron core block 14 divided into slots is formed by laminating electric iron plates 14a, and is integrated with an iron core retainer 14b having a dovetail 14c on the side opposite to the duct by means of both screw bolts 14d and nuts 14e.

This laminated core block 14 is radially arranged in the outer duct 12, and has a cylindrical core frame 1 having a dovetail groove on the inner peripheral side relative to the dovetail 14b.
7 is arranged on the outer peripheral side of the laminated core block 14, the laminated core block 14 is fitted in the dovetail groove, and is fixed by the cotter 17a.

Further, both ends (upper and lower ends) in the axial direction of the iron core frame 17
Is provided with a disc-shaped presser plate 18, and clamps the stator coil 15 and the laminated core block 14 as a whole.

In this way, the stator coil 15 and the laminated iron core block 14 are integrated with the iron core frame 17 to form a rigid body, and the stator coil 15 and the laminated iron core block 14 are mounted and supported on the flange provided in the lower portion of the casing 19 for accommodating the electromagnetic pump body. is doing.

On the other hand, as the material of each structural member, the outer duct 12 is made of stainless steel which has a high strength at high temperature and has a good property against a conductive fluid (sodium in this case). Further, in the laminated iron core block 14, a material having a thermal expansion coefficient smaller than or substantially the same as that of the outer duct 12 is used for the electric iron plate 14a, for example, a silicon steel plate.

Further, the iron core retainer 14b and the iron core frame 1
7 is made of the same iron material having a thermal expansion coefficient smaller than or substantially the same as that of the outer duct 12, for example, special steel such as chrome molybdenum steel. Next, the operation of the immersion type electromagnetic pump of the present embodiment configured as above will be described.

1 and 2, when the electromagnetic pump is in operation, the stator coil 15, which is a heat generating portion, becomes a high temperature portion, and the duct in contact with the conductive fluid becomes a low temperature portion, and heat is transferred between them. The laminated iron core block 14 and the iron core frame 17 serve as a middle temperature part.

In this case, in this embodiment, the outer duct 12
Since the laminated core block 14 and the core frame 17, which have a higher temperature than that of, are made of a material having a coefficient of thermal expansion smaller than that of the outer duct 12, an increase in a gap due to thermal expansion is caused in a portion in contact with the duct. You can almost eliminate it.

For example, with such a configuration, when the electromagnetic pump is in operation, the laminated core block 14 and the core frame 1 made of materials having almost the same coefficient of thermal expansion are used.
Since 7 has almost the same temperature, it can be considered as an integral cylinder.

Therefore, when the following conditions are satisfied during the operation of the electromagnetic pump, it is possible to prevent the increase of the gap due to the thermal expansion during the operation of the electromagnetic pump. That is,

Outer duct temperature 375 ° C. Laminated core block, core frame temperature 470 ° C. Thermal expansion coefficient of outer duct α1 = 17.89 × 10 ⁻⁶ Thermal expansion coefficient of iron core, iron frame α2 = 14.2 × 10 ^{− 6}

(A) Amount of thermal expansion of the outer diameter of the outer duct 12 from normal temperature during operation δ1 δ1 = α1 × L1 × (375-20) = 5.18 mm L1 = outer duct 12 outer diameter (815 mm)

(B) Thermal expansion amount of the inner diameter of the laminated core block 14 from normal temperature during operation δ2 δ2 = α2 × L2 × (470-20) = 5.21 mm L2 = inner diameter of the laminated core block 14 (815 mm)

(C) The relative displacement amount of the laminated core block 14 and the duct is δ = δ2-δ1 = 0.03 mm, and it is possible to make the gap hardly increase due to the thermal expansion during the operation of the electromagnetic pump.

As described above, during the operation of the electromagnetic pump, since there is almost no increase due to the thermal expansion of the gap, the heat generated in the stator coil 15 which is the heat generating portion can be efficiently released to the conductive fluid. As a result, it is possible to increase the amount of current flowing through the stator coil 15 and increase the capacity and size of the electromagnetic pump.

As described above, in the present embodiment, the inner duct 11 and the outer duct 12 are concentrically arranged to form the annulus passage 13 through which the conductive fluid flows, and thus the double cylindrical duct having the double pipe structure is formed. In order to radially arrange a plurality of laminated core blocks 14 each having a slot on the outer circumference of the outer duct 12 and to create a traveling magnetic field in the duct annulus flow passage 13 containing a conductive fluid in the slots of the laminated core blocks 14. In the submerged electromagnetic pump configured by arranging a large number of annular stator coils 15 for flowing the three-phase AC current, the dovetail 14c is provided on the outer peripheral side of the laminated core block 14.
Is provided, and is fitted to a cylindrical iron core frame 17 having a dovetail groove on the inner peripheral side relative to the dovetail 14c by a dovetail groove, and is fixed by a cotter 17a, whereby the laminated core block 14 is made into a cylindrical iron core. The stator coil 15 and the laminated core block 14 are fastened together by the disc-shaped pressing plates 18 fixed to the frame 17 at both ends of the core frame 17 in the axial direction so as to be integrated with the core frame 17 and house the electromagnetic pump body. The laminated core block 14 and the core frame 17 are made of a material having a coefficient of thermal expansion smaller than or substantially the same as that of the outer duct 12. .

Therefore, the laminated core blocks 14 and the iron frame 17 radially arranged on the outer periphery of the outer duct 12 are integrated, and the laminated core blocks 14 and 17 have a coefficient of thermal expansion higher than that of the outer duct 12. Since a material having a small or almost the same coefficient of thermal expansion is used, the gap between the outer duct 12 and the laminated core block 14 is minimized to improve heat transfer during operation of the electromagnetic pump, and the stator coil that is the heat generating portion is used. The heat generated in 15 can be efficiently released to the conductive fluid. This makes it possible to increase the amount of current flowing through the stator coil 15 and increase the capacity and size of the electromagnetic pump.

Therefore, in order to increase the capacity of the electromagnetic pump and make it more compact to save the installation place of the electromagnetic pump and bring out the advantages of the entire plant, the electromagnetic pump is immersed in the conductive fluid for operation. It is possible to sufficiently meet the recent strong demands.

In the above embodiment, the laminated core block 1
4 is provided with a dovetail 14c on the outer peripheral side, and is fitted to the cylindrical iron core frame 17 having a dovetail groove on the inner peripheral side facing the dovetail 14c by the dovetail groove and fixed by the cotter 17a. Although the case where the block 14 is fixed to the cylindrical core frame 17 has been described, the present invention is not limited to this and may have the following configuration.

That is, as shown in the transverse sectional view of FIG. 3, for example, the laminated core block 2 is replaced with the above-mentioned dovetail.
1 is provided with a convex guide on the outer peripheral side and has a cylindrical core frame 27 having a concave groove on the inner peripheral side facing the convex guide.
Even if the laminated core block 21 and the iron core frame 27 are fixed and integrated by fitting in the groove and fixing the bolts 29 from the outer periphery of the iron core frame 27, the same as in the case described above. The effect of can be obtained.

[0043]

As described above, according to the present invention, a laminated iron core having slots on the outer circumference of an outer pipe which is concentrically provided with an annulus passage for flowing a conductive fluid outside the inner pipe. A plurality of blocks are arranged radially, and in the slots of this laminated core block, a large number of annular stator coils that flow a three-phase alternating current to create a traveling magnetic field in the annulus passage are arranged, and the laminated core block is formed into a cylinder. Fixed to the core frame, and the stator core and the laminated core block are tightened by annular pressing plates provided at both ends in the axial direction of the core frame to be integrated with the core frame, and are mounted in a cylindrical casing. As the material of the laminated core block and the core frame, the one whose thermal expansion coefficient is smaller than or almost the same as that of the outer tube is used, so that the current flowing to the stator coil is increased,
It is possible to provide an extremely reliable submersible electromagnetic pump capable of achieving large capacity and compactness.

[Brief description of drawings]

FIG. 1 is a transverse sectional view showing an embodiment of an immersion electromagnetic pump according to the present invention.

FIG. 2 is a vertical sectional view showing an embodiment of the immersion type electromagnetic pump according to the present invention.

FIG. 3 is a cross-sectional view showing another embodiment of the immersion electromagnetic pump according to the present invention.

FIG. 4 is a cross-sectional perspective view showing a basic configuration example of a conventional electromagnetic pump.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inner duct, 2 ... Outer duct, 3 ... Annular passage, 4 ... Laminated core block, 5 ... Stator coil, 6 ... Laminated inner core, 7 ... Fluid inlet, 8 ... Fluid outlet, 11 ... Inner duct, 12 … Outside duct, 13… Annulus channel, 1
4 ... Laminated core block, 14a ... Electric iron plate, 14b ... Iron core retainer, 14c ... Dovetail, 14d ... Both screw bolts, 14e ... Nut, 15 ... Stator coil, 16 ... Laminated inner core, 17 ... Iron core frame, 17a ... Cotter, 18 ... Pressing plate, 19 ... Casing, 21 ... Laminated core block,
27 ... iron core frame, 29 ... bolts.

Claims (3)

[Claims] 1. A plurality of laminated core blocks having slots are radially arranged on the outer circumference of an outer pipe which is concentrically provided with an annulus passage for flowing a conductive fluid outside the inner pipe.
In the slot of the laminated core block, a large number of annular stator coils for flowing a three-phase alternating current for creating a traveling magnetic field in the annulus passage are arranged, and the laminated core block is fixed to a tubular core frame. , The stator coil and the whole laminated core block are tightened by annular pressing plates provided at both ends in the axial direction of the iron core frame to be integrated with the iron core frame and mounted in a cylindrical casing, and the laminated core block and An immersion electromagnetic pump, characterized in that a material having a coefficient of thermal expansion smaller than or substantially the same as that of the outer tube is used as a material of the iron core frame. 2. The laminated core block is provided with a dovetail on an outer peripheral side thereof, and is fitted with a tubular core frame having a dovetail groove on an inner peripheral side relative to the dovetail by the dovetail groove, and by a cotter. The immersion type electromagnetic pump according to claim 1, which is fixed. 3. The laminated core block is provided with a convex guide on an outer peripheral side thereof, and a cylindrical core frame having a concave groove on an inner peripheral side facing the convex guide is provided on the cylindrical core frame by the groove. The immersion type electromagnetic pump according to claim 1, wherein the immersion type electromagnetic pump is fitted and fixed by bolts from the outer periphery of the iron core frame.