JPH06121521A - Electromagnetic pump - Google Patents

Abstract

PURPOSE:To provide an electromagnetic pump in which heat generated in a stator coil section can be dissipated efficiently to the outside, efficiency can be enhanced in heat recovery and in pump, and preheating can be carried out without causing a significant temperature difference in the electromagnetic pump. CONSTITUTION:The electromagnetic pump comprises a double cylindrical duct for feeding conductive fluid to an annulus channel 3 formed between inside and outside duscts 5, 4, a plurality of laminated core blocks 1 having slots disposed on the outer periphery of the double cylindrical duct, and a large number of stator coils 2 for feeding AC three-phase current to establish a traveling field in the annulus channel arranged in the slot of the laminated core block 1 where the conductive fluid is present. Thermal insulation material 12 is placed in a casing 9 containing the laminated core block 1 and the stator coil 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-phase AC induction type in which a traveling magnetic field is applied to a conductive fluid from outside to induce an induced current in the fluid, and a pumping action is caused by the interaction between the induced current and the external magnetic field. Regarding electromagnetic pumps.

[0002]

2. Description of the Related Art In a three-phase induction type electromagnetic pump, three-phase AC windings are arranged in the direction of flow of the electromagnetic pump in order of distribution of respective phases. A traveling magnetic field is generated at. If this traveling magnetic field is made to pass through a duct containing a conductive fluid, Fleming's right-hand rule induces a voltage in the fluid, 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 by receiving the force so that the fluid flows. This electromagnetic force is the same as the torque in the induction motor and the advancing force in the linear motor. The three-phase induction type electromagnetic pumps are roughly classified into two types: (1) flat linear type electromagnetic pumps and (2) annular linear type electromagnetic pumps. The present invention relates to an annular linear type electromagnetic pump, and the structure thereof will be described below.

Since an annular linear type electromagnetic pump has an annular flow passage cross section, it has an ALIP (Annular Linear Inducer)
Abbreviation of tion pump). Since the duct structure has high reliability and safety, it is an electromagnetic pump that has become mainstream in recent years. Figure 2 shows the basic structure of ALIP. The structural features include the following. (1) The duct through which the conductive fluid flows has a concentric double-tube structure by the outer duct 4 and the inner duct 5, and forms the annulus passage 3 through which the fluid flows.

(2) On the stator, a plurality of laminated iron core blocks 1 each having an iron core having slots for forming a magnetic circuit of an alternating magnetic field stacked in the circumferential direction are arranged outside the outer peripheral duct 4 in the circumferential direction. . In this case, the laminated surface faces the duct, and the slots are further inward so that the entire iron core is radial. A ring-shaped stator coil 2 is arranged in this slot. A large number of coils are arranged in the axial direction and are connected so that a three-phase alternating current creates a traveling magnetic field. (3) Inside the inner duct 5, a laminated inner iron core 6 for forming a magnetic circuit is housed. (4) The fluid enters the electromagnetic pump through the inlet 7, pressure is induced while flowing through the annulus flow path 3, and exits through the outlet 8. (5) The coil 2 is an external fan (not shown)
It is cooled by the circulating gas.

In recent years, the electromagnetic pump has been made more compact in order to increase the capacity of the electromagnetic pump and eliminate restrictions on the installation place to improve the design of a plant using the electromagnetic pump. It has been required to operate submerged in a fluid to provide advantages. As a method of satisfying the above requirements, the coil is not cooled by forced gas cooling as in the conventional case, but it is necessary to cool the surface of the jacket without circulating the cooling gas. This has many advantages as follows. (1) The space for circulating the cooling gas can be omitted, and the external dimensions can be reduced. (2) An external device for circulating the cooling gas is unnecessary. (3) Since the piping for circulating the cooling gas between the main body and the external device is not required, there is a great advantage as the immersion type.

(4) Further, when the outer surface is cooled, the coil can be arranged in the internal iron core, which cannot be done by the conventional machine when the machine becomes a large-capacity machine to some extent, so that the output of the electromagnetic pump is further increased and the apparatus is more compact. You will be able to.

In the case of cooling the surface of the jacket, it is necessary to transfer the heat loss generated in the coil from the coil to the iron core, and from the iron core to the duct or frame to release the heat into the fluid. Therefore, it is important to reduce the thermal resistance from the coil to the fluid as much as possible, and for that reason, the point is that those structures are in contact with each other during operation.

[0008]

However, in order to maximize the output of the electromagnetic pump, a large amount of current is passed through the coil. For this reason, it is necessary to minimize the temperature rise of the coil. In general, a conductive fluid having a high temperature is used in many cases, so that the electromagnetic pump immersed in the conductive fluid is operated at a high temperature.

Electromagnetic pumps are assembled at room temperature and can
It is operated at various temperatures below 00 ° C. Therefore, at any temperature, it is necessary to efficiently release the heat generated in the coil to the fluid so as not to be stressed by the difference in thermal expansion between the structures.

In order to increase the pump capacity and make it compact with such an electromagnetic pump, the heat generated in the stator coil, which is the heat generating portion, is efficiently released to the fluid, so that the current flowing in the stator coil is increased. The point is to do as much as possible.

In the conventional electromagnetic pump, the heat generated in the coil is transferred to the outer duct through the block and transferred from the outer duct into the conductive liquid. However, a gap is required between the duct and the laminated core block to escape the difference in thermal expansion, and this gap reduces heat transfer, and there is a problem that the heat generated in the coil cannot be efficiently released to the fluid. It was Further, it is difficult to uniformly raise the temperature of the electromagnetic pump, such as a slow rate of temperature rise at the bottom of the casing during preheating and a large temperature difference between the upper and lower external ducts.

The present invention has been made in order to solve the above problems, and can efficiently dissipate the heat generated in the stator coil portion to the outside, improve the efficiency of heat recovery, improve the pump efficiency, and improve the preheating. An object of the present invention is to provide an electromagnetic pump that can be easily preheated without causing a large temperature difference in the electromagnetic pump.

[0013]

DISCLOSURE OF THE INVENTION The present invention has a double cylindrical duct for flowing a conductive fluid in an annulus passage formed between the outer duct and a slot arranged on the outer circumference of the double cylindrical duct. Electromagnetic composed of a plurality of laminated core blocks and a large number of stator coils for flowing a three-phase alternating current to create a traveling magnetic field in the annulus flow path in which the conductive fluid is arranged in the slots of the laminated core blocks. In the pump, a heat-resistant insulating material is arranged in a casing that houses the laminated core block and the stator coil.

[0014]

The heat generated in the stator coil portion is dissipated from the outer duct and the casing to the conductive fluid through the heat resistant insulating material. The heat generated in the stator coil portion due to this heat dissipation can be recovered in the conductive fluid, and the efficiency of the pump can be improved. Further, the heat generated in the stator coil portion at the time of preheating can be transmitted to the entire electromagnetic pump through the heat resistant insulating material, and the temperature can be uniformly raised.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an electromagnetic pump according to the present invention will be described with reference to FIG. 1 is a vertical cross-sectional view showing the structure of the electromagnetic pump. That is, the plurality of laminated core blocks 1 are arranged in the casing 9 at substantially equal intervals in the circumferential direction, and a large number of stator coils 2 are arranged inside the laminated core block 1 in the axial direction. Further, in the laminated core block 1, an outer duct 4 and an inner duct 5 forming an annulus passage 3 are arranged in a double cylindrical duct structure. An inner iron core 6 is inserted in the inner duct 5. The lower side of the annulus channel 3 shown in FIG. 1 is a fluid inlet 7 into which a conductive fluid flows, and the upper side is a fluid outlet 8. The casing 9 is filled with a heat-resistant insulating material 12 from the bottom of the casing to the vicinity of the fluid surface 10, and the upper part is immersed in the fluid while being kept in the atmosphere of the inert gas 11. The relationship between the inner duct 5 and the inner iron core 6 is the same as that of the conventional structure, and the description thereof is omitted.

In the electromagnetic pump having the above structure, however, the heat generated in the stator coil 2 is transferred to the outside of the outer duct 4 and the casing 9 via the heat resistant insulating material, and is efficiently recovered by the fluid, so that the stator coil The calorific value of 2 can be increased, and a small-sized and large-capacity electromagnetic pump can be configured. Further, the heat generated in the stator coil 2 at the time of preheating is transmitted to the entire inside of the casing 9 through the heat resistant insulating material 12, and it becomes easy to uniformly preheat the inside of the electromagnetic pump.

[0017]

According to the present invention, the heat generated in the stator coil can be efficiently removed, the temperature rise of the stator coil can be suppressed, and the heat generation of the stator coil can be made larger than before. . Therefore, the efficiency of the pump is improved,
It is possible to provide a more compact and large-capacity electromagnetic pump. Moreover, the preheating of the electromagnetic pump can be easily performed.

[Brief description of drawings]

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

FIG. 2 is a perspective view showing a conventional electromagnetic pump with a part cut away.

[Explanation of symbols]

 1 ... Laminated core block 2 ... Stator coil 3 ... Annulus flow path 4 ... Outer duct 5 ... Inner duct 6 ... Inner core 7 ... Fluid inlet 8 ... Fluid outlet 9 ... Casing 10 ... Fluid surface 11 ... Inert gas atmosphere 12 … Heat resistant insulation

Claims (2)

[Claims] 1. A double cylindrical duct for flowing a conductive fluid in an annulus passage formed between an outer duct and an inner duct, and a plurality of laminated cores having slots arranged on the outer periphery of the double cylindrical duct. In an electromagnetic pump consisting of a block and a number of stator coils that flow a three-phase alternating current to create a traveling magnetic field in the annulus flow path in which the conductive fluid is placed in the slots of the laminated core block, An electromagnetic pump, characterized in that a heat-resistant insulating material is provided in a casing that houses a laminated core block and a stator coil. 2. The electromagnetic pump according to claim 1, wherein the heat-resistant insulating material is one member selected from aluminum oxide, beryllium oxide, silicon nitride, magnesia, and insulating oil for high temperature.