JP3281051B2 - Electromagnetic pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a center return type or one-through type annular linear three-phase induction electromagnetic pump, and particularly to a coolant circulation pump in a liquid metal cooled reactor under a high temperature environment. To an electromagnetic pump.

[0002]

2. Description of the Related Art In a liquid metal-cooled reactor using a liquid metal as a coolant (sodium is often used as a liquid metal, hereinafter referred to as liquid sodium), a liquid sodium coolant used in a high temperature environment is used. Large-capacity three-phase induction electromagnetic pumps such as circulation pumps are classified into two types, flat linear type and annular linear type, according to their structures.
The present invention is directed to an annular linear type.

Since the annular linear electromagnetic pump has an annular cross-section in which the duct has a double concentric arrangement of ducts, ALIP (abbreviation for Annular Linear Induction Pump) is used.
is called. ALIP is suitable for large-capacity reactor coolant circulation pumps because of its high reliability and safety of the duct structure.

The structure of a center return type electromagnetic pump will be described with reference to FIG. 4, reference numeral 1 denotes an outer stator core, 2 denotes an outer stator coil, 3 denotes an inner stator core, 4 denotes an inner stator coil, and 5 denotes a sodium channel. Reference numeral 6 denotes a cylindrical casing, in which an outer duct 10 and an inner duct 11 are arranged concentrically, an outer stator 15 is provided in the outer duct 10, and an inner stator 16 is provided in the inner duct 11. Have been.

The outer stator 15 is formed by combining the outer stator core 1 and the outer stator coil 2, and the inner stator 16 is formed by combining the inner stator core 3 and the inner stator coil 4. The lower end of the casing 6 is supported by a lower support plate 14.

The outer duct 10 and the inner duct 11 form a concentric double duct made of a stainless steel cylindrical body.
An annular sodium channel 5 is formed between 0 and 11. These ducts 10 and 11 are formed in an annular shape and have high strength and high reliability. In the drawing, reference numeral 7 denotes a center return pipe connected to the inner duct 11, 8 denotes a head plate connected to the upper end of the outer duct 10, and 9 denotes a center return portion formed below the head plate 8.

An outer stator 15 and an inner stator 16 are provided on the outer side of the outer duct 10 and on the inner side of the inner duct 11, respectively. The stators 15 and 16 are each formed of a comb-shaped outer stator core 1 and inner stator core 3 and a ring-shaped stator. , And an outer stator coil 2 and an inner stator coil 4.

[0008] Liquid sodium flows into the opening of the lower support plate 14 from the lower fluid traveling direction 13 and rises between the outer duct 10 and the inner duct 11, and as shown by the fluid traveling direction 13 above the sodium channel 5. The flow is reversed from the center return section 9 and flows down in the center return pipe 7.

The sodium flow path 5 includes a once-through type in which liquid sodium flows only in one direction and a center return type in which the flow of liquid sodium is reversed at the upper end of the center return pipe 7 as shown in FIG. is there. The present invention is applied to both the once-through type and the center return type.

The outer stator coil 2 and the inner stator coil 4 are repeatedly arranged in the order of U-phase, V-phase, and W-phase. When a three-phase alternating current is applied to each of these phases, a moving magnetic field is generated. The interaction between the moving magnetic field and the induced current flowing in the liquid sodium generates a thrust in the liquid sodium.

Annular linear type electromagnetic pumps are mainly classified into two types, a single stator (single stator) type and a double stator (double stator) type. In the single stator type, a radial stator core and a ring-shaped coil are disposed only on the outside of the outer duct 10, and a laminated inner core for forming a magnetic circuit is housed inside the inner duct 11, In the double stator type, a radial stator core and a ring-shaped coil are arranged outside the outer duct and inside the inner duct.

[0012]

SUMMARY OF THE INVENTION In a high-temperature environment where an electromagnetic pump is used, an improvement in earthquake resistance and a casing
Conventionally, it has been a problem to cope with the thermal expansion difference absorption between the center return pipe 7 and the inner stator 16 and the outer stator 15. Regarding the method of fixing each of the stators 15 and 16, it is necessary that the radial direction of the stators 15 and 16 where the stators 15 and 16 easily swing are restricted from the viewpoint of earthquake resistance, and that the axial directions where the stators 15 and 16 are easy to expand are free from the viewpoint of thermal expansion. .

However, when the annular linear electromagnetic pump is used at a high temperature, the inner and outer stator
There is a problem that it is difficult to improve the seismic resistance of 16 and 15 while absorbing thermal expansion.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and secures the soundness of the structural material by reducing the repetitive thermal stress generated in the structural material and suppressing the vibration of the structural material due to an external excitation force such as an earthquake. Another object of the present invention is to provide a highly reliable electromagnetic pump.

[0015]

The invention according to claim 1 is
A cylindrical stator for generating electromagnetic force in the axial direction;
Provided inside the stator, the electromagnetic force of the stator
A cylindrical duct that forms a flow path for the fluid
A casing provided outside the stator;
The duct and the casing
The axial and radial positions of the stator with respect to
And a slide mechanism for elastically supporting the rider . The invention according to claim 2, wherein the slide
The mechanism comprises a spring and a slide connected to the spring and having a sliding surface.
And an id plate. Claim 3
According to the invention, the slide mechanism regulates a displacement of a predetermined amount or more.
It is characterized by having a stopper to perform.

[0016]

In the present invention, the axial thermal expansion differences between the casing and the outer stator, and between the cylindrical duct and the inner stator, are close to the outer stator uppermost casing side, the inner stator uppermost center return pipe side, and the outer stator lowermost casing side. And it is absorbed by the axial slide mechanism provided near the lowermost center return pipe side of the inner stator.

That is, the casing and the outer stator, the center return pipe and the inner stator slide, and the thermal expansion absorbing spring and stopper of the radial slide mechanism provided near the upper stator return casing side of the outer stator and near the upper center return pipe side of the inner stator. Absorbed at the appropriate gap.

The difference in radial thermal expansion between the casing, the outer stator, and the center return pipe and the inner stator is determined by the radial slide mechanism in which the casing, the outer stator, the center return pipe, and the inner stator slide, and the axial slide mechanism Is absorbed at an appropriate gap by the thermal expansion difference absorbing spring and stopper.
As described above, the thermal stress of the structural material can be reduced.

Since the axial slide mechanism and the radial slide mechanism are each provided with a stopper, even if an excitation force is applied from the outside, the radial direction between the casing and the outer stator and between the center return pipe and the inner stator is reduced. The relative displacement of the outer stator,
The same effect as increasing the rigidity of the inner stator, casing, and center return pipe is produced, and the earthquake resistance is improved. As described above, the soundness of the structural material can be secured.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an electromagnetic pump according to the present invention will be described with reference to FIGS. FIG. 1 shows a cross section of a center return type electromagnetic pump, and FIG. 2 shows an enlarged “A” part of FIG. In the figure, the same parts as those in FIG.

That is, in FIG.
The axial stator fittings 24 are provided at a plurality of locations on the inner circumferential side of the casing 6 near the uppermost portion of the inner stator 16 and on the outer circumferential side of the cylindrical duct 12 connecting the center return pipe 7.
And the radial stator fittings 25 are fixed by welding.
Preparative surrounds the outer stator 15 Contact and inner stator 16
A stopper 23 is welded and fixed to the outside and inside of the stator mounting bracket 17 for attachment .

The outer stator 15 and the inner stator 16
Inside the casing 6 and the cylindrical duct 12 near the bottom of the
The radial stator fittings 25 are welded and fixed at a plurality of locations in the outer circumferential direction, thereby receiving the outer stator 15 and the inner stator 16. The thermal expansion difference absorbing spring 22 is
However, a slide plate 21 is provided at the tip of the thermal expansion difference absorbing spring 22.

The outer stator 15 and the inner stator 16 are received by the stator receiving hardware through the slide plate 21 to absorb a difference in radial thermal expansion between the casing 6, the outer stator 15, the center return pipe 7, and the inner stator 16. And absorbs the difference in axial thermal expansion between the casing 6 and the outer stator 15 and between the center return pipe 7 and the inner stator 16.

Since the axial slide mechanism 19 and the radial slide mechanism 20 are each provided with a stopper 23, the relative displacement can be restrained even when an external excitation force such as an earthquake is applied.

In FIG. 2, the axial stator receiving metal 24
In addition, the radial stator fitting 25 is fixed to the cylindrical duct 12 by welding. The stopper 23 is fixed to the upper and lower ends of the stator mounting bracket 17 by welding. An iron core 18 is provided inside the stator mounting bracket 17.

Since the stopper 23 is provided outside the stator mounting bracket 17 as described above, the stopper 23, the axial stator receiving member 24, and the radial stator receiving member 24 are provided.
Between 25, the relative displacement in the axial direction and the radial direction is restricted, respectively.

A thermal expansion difference absorbing spring 22 is provided on the stopper 23. The thermal expansion difference between the stator and the cylindrical duct 12 in the radial direction is absorbed by the thermal expansion difference absorbing spring 22 of the axial sliding mechanism 19, and the axial thermal expansion difference is absorbed by the thermal expansion absorbing spring 22 of the radial sliding mechanism 20.

A slide plate is provided at the end of the thermal expansion differential absorption spring 22.
The relative displacement in the axial direction between the stator including the iron core 18 and the cylindrical duct 12 is provided by the slide plate 21 of the axial slide mechanism 19, and the relative displacement in the radial direction is provided by the radial slide mechanism 20.
Sliding plate 21 is possible to reduce the thermal stress of the structural material constituting the electromagnetic pump by each axis stator receiving hardware 24 and radial stator receiving hardware 25 and relative displacement.

Next, another embodiment of the present invention will be described with reference to FIG. 3, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description of the overlapping parts will be omitted. FIG. 3 differs from FIG. 1 in that a plurality of axial slide mechanisms 19 are provided not only near the upper and lower portions of the radial stator fitting 25 but also in the axial direction between them. The other parts are the same as in FIG.

According to this embodiment, the seismic resistance can be further improved as compared with the embodiment of FIG. The number and arrangement of the axial slide mechanism and the radial slide mechanism are not particularly limited.

[0031]

According to the present invention, while restraining the relative radial displacement of the scan stator eliminates axial thermal expansion difference and the radial thermal expansion difference occurs with axial thermal expansion differential between the casing and the stator, also an earthquake or the like outside Relative displacement due to excitation force
In Rukoto enhance the resistance to vibration and restrained, it is possible to provide a more reliable electromagnetic pump.

[Brief description of the drawings]

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

FIG. 2 is an enlarged longitudinal sectional view showing a portion A in FIG. 1;

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

FIG. 4 is a sectional view showing a conventional electromagnetic pump.

[Explanation of symbols]

1 ... outer stator core, 2 ... outer stator coil, 3 ...
Inner stator core, 4 inner stator coil, 5 sodium flow passage, 6 casing, 7 center return pipe, 8 head plate, 9 center return section, 10 outer duct, 11 inner duct, 12 cylindrical duct , 13: Fluid traveling direction, 14: Lower support plate, 15: Outer stator, 16: Inner stator, 17: Stator mounting bracket, 18: Iron core, 19: Axial slide mechanism, 20: Radial slide mechanism, 21: Slide Plate, 22: Differential thermal expansion absorption spring, 23: Stopper, 24: Axial stator receiving hardware, 25: Radial stator receiving hardware.

Claims (3)

(57) [Claims] 1. A cylindrical switch for generating an electromagnetic force in an axial direction.
A stator and an electromagnetic force of the stator provided inside the stator.
Cylindrical duct that forms a flow path for a fluid that travels
A casing provided outside the stator; a casing provided around the stator;
Axial position and radial direction of the stator with respect to the casing
Electromagnetic pump, characterized in that it comprises position and slide mechanism slidably resiliently supports the, the. 2. The slide mechanism according to claim 1, further comprising: a spring;
And a slide plate having a sliding surface connected to the
The electromagnetic pump according to claim 1, wherein: 3. The slide mechanism according to claim 2, wherein said slide mechanism has a displacement of a predetermined amount or more.
2. A stopper for regulating the pressure.
Electromagnetic pump as described.