JPH02184259A - Solenoid pump - Google Patents

Abstract

PURPOSE:To increase the degree of freedom of designing and restrict nonequilibrium current by a method wherein an least one of inside and outside ducts is provided with a plurality of coils 3-phase AC winding, which forms the magnetic field of traveling wave in electroconductive fluid, and a plurality of circuit conductors constituting a parallel circuit in respective phases, is received in the same coil. CONSTITUTION:A concentric double-tube of stainless steel, which is constituted of an inside duct 6 and an outside duct 5, is provided with the annular flow passage 2 of electroconductive fluid while coils 1, forming the magnetic field of traveling wave in an outer core 3, are provided in the outer core 3. Three pieces of parallel circuit coils are provided in the slots of the core 3 and conductors, constituting three pieces of parallel circuits, are received in one coil so as to be capable of being led out of the same place on the circumference of the core respectively. According to this method, the degree of freedom in the designing of a solenoid pump may be increased and nonequilibrated current may be restricted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an electromagnetic pump that applies a traveling magnetic field to a conductive fluid from the outside to cause a pumping action of the fluid.

(Prior art) The basic operating principle of an electromagnetic pump is to apply current to a conductive fluid placed in a magnetic field, and to generate a force (Bo
by Force), and is based on Fleming's left-hand rule. When the magnetic flux density of the magnetic field is B1 and the current density in the fluid is J, the force F generated per unit volume of fluid is expressed by the following equation.

-JXB Electromagnetic pumps can be roughly divided into the following two types depending on the method of applying current to the fluid.

(1) It is based on the same principle as a DC motor, and is a method in which a current is passed directly into the fluid from the outside via electrodes in contact with the fluid. This is called a conduction type.

(2) It is based on the same principle as an induction motor, and is a method in which a moving magnetic field is applied to a fluid from the outside, thereby inducing a current in the fluid. This is called an induction type.

The present invention relates to the derived form (2) of these,
In particular, it relates to a three-phase induction type electromagnetic pump that uses three-phase alternating current.

A three-phase induction electromagnetic pump has three-phase AC windings distributed in the order of each phase in the direction of flow of the electromagnetic pump, and when three-phase AC is applied to these windings, a traveling magnetic field is generated in the direction of fluid flow. Occur. If this traveling magnetic field also passes through a duct containing a conductive fluid, a voltage will be induced in the fluid according to Fleming's right-hand rule, which will cause an induced current to flow. This induced current and some components of the traveling magnetic field act to create an electromagnetic force, which acts as a pump by receiving force so that the fluid flows.

This electromagnetic force corresponds to the torque in an induction motor and the thrust in a linear motor.

Three-phase induction electromagnetic pumps can be roughly divided into the following two types based on their structure.

(1) Flat linear electromagnetic pump Due to its duct shape, the flat linear electromagnetic pump
LIP (Flat Linear Induction)
(abbreviation of Pump). The following points can be mentioned as structural features.

■ The duct is made of thin stainless steel plates to form a straight flow path with a flat, rectangular cross section. Since the loop piping outside the pump is circular, it is connected with a widening pipe whose flow path shape gradually changes.

■ The stator that generates the traveling magnetic field consists of three-phase AC windings and a laminated iron core. The winding is fixed by placing the opposing straight parts of the hexagonal coil, which form one loop on a plane, into the grooves of the iron core. A stator consisting of a winding and an iron core is assembled to face each other with a duct in between.

Conventionally, the gap between the stator and the duct is thermally insulated with a heat insulating material to prevent the duct from being cooled.

■ Since the stator is divided into upper and lower sections as described above, the stator can be removed without cutting the pipes or ducts, which has the advantage of facilitating maintenance and inspection.

Because of these characteristics and the same structure as familiar electric machines such as near motors, it has been the most commonly manufactured induction type electromagnetic pump to date.

(2) Annular linear electromagnetic pump Since the annual linear electromagnetic pump has an annular flow path cross section, it is called ALIP (Annual Linear In
It is called duction (abbreviation of Pumo). Electromagnetic pumps have become mainstream in recent years because of their highly reliable and safe duct structure.

FIG. 1 shows the basic structure of AL(P.The following points are listed as structural features.

■ The duct is a stainless steel double-pipe tube that forms an annulus flow path. The duct has a cylindrical shape and has excellent strength, so it can be said to be a highly reliable duct structure.

■ The stator is installed outside the duct and consists of a radial iron core and a ring-shaped coil.

■ A laminated internal iron core for forming a magnetic circuit is housed inside the inner duct.

The coils of these electromagnetic pumps are arranged alternately in phase order for each phase group along the flow direction. Each phase group is electrically connected together in series to form a series circuit, and each phase circuit is connected to a Y-shaped or Δ-shaped circuit steel according to each requirement. There is.

(Problem to be Solved by the Invention) Generally, in an AC machine, the number of parallel circuits in each phase group is selected freely to some extent as a degree of freedom in designing these connections. For example, if the number of parallel circuits is N for a design in which the number of parallel circuits is 1, the current will be N times higher, but the voltage will only need to be 1/N times higher. Therefore, it was possible to create an optimal design depending on the power supply and control. Furthermore, this multi-parallel circuit is formed by wiring between coils, and therefore all the conductors within the coil belong to the same parallel circuit. However, in the case of this electromagnetic pump, since there are iron core ends at the inlet and outlet of the flow path, among the coils forming the parallel circuit, the coil 10 at the end and the other coils 11, 12, as shown in FIG. Since the impedances of the coils are different, impedance imbalance occurs in the in-phase parallel circuit as shown in FIG. Here, only the U phase is shown to make the explanation easier to understand. When voltage is applied to these, the load current differs for each parallel circuit, and the desired current does not flow in some coils, while in other coils more than the desired current flows, causing coil loss and coil temperature to rise. In addition, only a traveling magnetic field with large distortion can be obtained, and the electromagnetic force applied to the conductive fluid cannot be said to be efficient.

Therefore, the coil connection must be designed with one parallel circuit, especially in large-capacity electromagnetic pumps where unbalanced currents are a problem.Therefore, there is no degree of freedom in design, and it is difficult to create a large-capacity machine. The more the operating voltage increases, the more reliability and economics problems arise in the power supply, coils, etc.

The present invention was made in view of the above-mentioned problems, and in particular, it allows the number of parallel circuits to be arbitrarily selected in the wiring of a three-phase induction electromagnetic pump, dramatically increasing the degree of freedom in design, and reducing unbalanced current. The purpose is to provide a highly reliable electromagnetic pump without any problems.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, in the electromagnetic pump of the present invention, a conductive fluid flow path is formed by an inner duct having an internal iron core and an outer duct having an outer iron core, and In an electromagnetic pump equipped with a three-phase AC winding consisting of a plurality of coils that forms a traveling wave magnetic field in a conductive fluid in the flow path on at least one side, conductors of a plurality of circuits forming parallel circuits of each phase. are stored in the same coil.

(Function) The present invention is constructed as described above, and by housing the conductors of all the circuits forming the parallel circuit in each phase in the same coil, the electrical conditions for the slot positions of each circuit are completely eliminated. Since they can be made the same, it is possible to eliminate differences in impedance between coils constituting a parallel circuit due to differences in slot positions and impedance unbalance of the parallel circuit, and it is possible to eliminate unbalanced current.

(Example) An embodiment of the present invention will be described with reference to the drawings.

Figure 1 is a cross-sectional view of the main parts of an Anislaricia type electromagnetic pump.The duct is a stainless steel double pipe consisting of an inner duct 6 and an outer duct 5. An internal iron core 4 for forming a magnetic circuit is housed inside the duct 6. Further, an outer core 3 is provided radially around the outer periphery of the outer duct 5, and a ring-shaped coil 1 is housed in a slot formed in the outer core.

Next, the method of winding the conductor in the coil 1 will be explained with reference to FIG.

Figure 2 shows an example of the winding method in the case of three parallel circuits, and the three parallel circuit coils 15 are the conductors 1B.

17 and 18 are wound three times each in a pancake shape, and are formed in two rows, a left row 19 and a right row 20. Figure 2
1, 22, and 23 indicate the transition portions of the conductors 1B and 17.18 from the left column 19 to the right column 20, respectively.

FIG. 3 shows a cross-sectional view of the coil 15 housed in the slot.

Next, the effects of this embodiment will be explained.

The current flowing through the conductor 1B enters from the outlet tea of the conductor 1B in the left row 19, and after making one and a half revolutions around the left column 19, the current flows from the left row 19 of the conductor 1B at a point exactly 180 degrees opposite to the outlet lea. It flows into the right column 20 through the crossing 21 to the right column 20. Furthermore, after one and a half rotations in this right row 20, right row 2
0 to the lead-out portion 18b of the conductor 16. As a result, the lead portion 16a of the conductor 16 of the coil 15 is formed.

18b can be taken out from the same location. Conductor 1
By applying the same winding method to 7.18, 17
a and 17b, 18a and 18b can also be taken out from the same location, and the conductors 16°1 making up the 3 parallel circuit
7 and 18 can be inserted into one coil 15 from the same location on the circumference. FIG. 4 shows how the coil 15 constructed in this manner is led out.

As described above, according to this embodiment, it is possible to disperse the lead-out, and the space required for wiring between the coils can also be distributed, so that it is possible to downsize the electromagnetic pump itself.

Figure 5 shows two crossover wires between coils when the number of parallel circuits is 3.
An example of connection according to 7 is shown. In this way, if it becomes possible to configure the coils of each phase with parallel circuits, for example, even if one of the parallel circuits becomes defective, other circuits can be used, so there is a risk that the electromagnetic pump itself will not work at all. This will dramatically improve the reliability of the electromagnetic pump.

Furthermore, in the winding method within one coil, the crossing portion of the coil from the left column 19 to the right column 20 is distributed as shown in Figure 2, so the height dimension of the coil when the conductor is crossed is It is also possible to prevent loss, and it can be made the most compact as a coil with the same number of parallel connections and the same number of turns.

As another example, FIG. 6 shows how the coils 24, 25, 2G are connected when the number of parallel circuits is 2,4,6.

Furthermore, as shown in FIG. 7, by connecting two rows of pancake-shaped windings on the outer circumferential side, openings 29a and 29b,
30a and 30b can be led out from the same location, and it is also possible to realize one coil 28 having any even number of windings.

〔Effect of the invention〕

As explained above, according to the present invention, the conductors of the plurality of circuits constituting the parallel circuit of each phase are housed in the same coil. By dispersing the conductor, the coil can be made smaller, and the electromagnetic pump can be made smaller and its reliability can be greatly improved. Additionally, since the number of parallel circuits can be selected arbitrarily, it is possible to design the electromagnetic pump optimally according to the power supply and control. Furthermore, unbalanced current is suppressed by eliminating impedance unbalance between parallel circuits, excess loss in the coil due to this current, localized overheating of the coil, etc. are also suppressed, improving pump reliability and performance. It can greatly contribute to improvement.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of essential parts of an annular linear electromagnetic pump according to an embodiment of the present invention, Fig. 2 is a diagram showing how to wind the conductor in the coil shown in Fig. 1, and Fig. 3 is a diagram showing the slots shown in Fig. 1. 4 is a cross-sectional view of the inner conductor, FIG. 4 is a diagram showing how the coil 15 in FIG. ), (b), and (c) each have a parallel circuit count of 2. 4. Figure 7 is a diagram showing the outline of a coil with 4 rows of conductors arranged horizontally, Figure 8 is a diagram showing the configuration of slots and coils of a conventional electromagnetic pump, and Figure 9 is a diagram showing the configuration of a coil with 4 rows of conductors arranged horizontally. The figure shows a circuit diagram in which one phase is composed of three parallel circuits. 1... Coil, 2... Conductive fluid flow path,
3... External iron core, 4... Internal iron core, 5...
Outer duct, 6...Inner duct, 15...3
Coils of parallel circuit, 15a, 15b, 158... Coil cross section, 16.
17.18...Conductor forming a parallel circuit, 16a,
17a, 18a... Leading out of the left row part of the conductor, 16b
, 17b, 18b... Output of the right row part of the conductor, 19.
...Left row of coil conductors, 20...Right row of coil conductors, 21.22.23...Bridge between left and right rows of conductors. Agent Patent Attorney Nori Ken Yudo Daishimaru Health Insurance System (C)

Claims (1)

[Claims] A flow path for a conductive fluid is formed by an inner duct having an internal iron core and an outer duct having an outer iron core, and at least one of the ducts includes a plurality of coils forming a traveling wave magnetic field in the conductive fluid in the flow path. An electromagnetic pump comprising a three-phase AC winding, characterized in that conductors of a plurality of circuits constituting parallel circuits of each phase of the winding are housed in the same coil.