RU2529521C1 - Electromagnetic induction pump - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention relates to an electrical engineering, to MHD-TECHNIQUE, in particular to electromagnetic induction pumps for pumping of pool metals on atomic power plants, in chemical and metallurgical industries. The electromagnetic induction pump includes the thermal screen located between inductor and channel. The pump has an average diameter D, longitudinal axis of the channel, inductor coil with active length, number of pairs of poles p, polar graduations τ. The thermal shield is made as a spiral with k turns, the split line of which an angle of inclination to the longitudinal axis of the channel, where k - positive integer value.

EFFECT: improvement of efficiency and operational life.

4 cl, 3 dwg

Description

The invention relates to MHD technology, in particular to electromagnetic induction pumps for pumping liquid metals in nuclear power plants, in the chemical and metallurgical industries.

A number of designs of linear cylindrical (CLL) and screw (VIN) induction electromagnetic pumps (EMN) are known, the main nodes of which are an inductor with a winding and a channel formed by coaxial shells with an internal magnetic circuit [Glukhikh VA, Tananaev AV, Kirillov I.R. Magnetic hydrodynamics in nuclear power. M .: Energoatomizdat. - 1987. - p. 196, Fig. 6.4 (a, b, d)]. The coil of the inductor creates a traveling magnetic field, in the interaction of which with the currents induced in the liquid metal, electromagnetic forces arise, which ensure the movement of the liquid metal.

However, such constructions of induction EMN have disadvantages. In them, the heat flux from the channel heats the inductor, including the winding of the induction EMN, which leads to an increase in the temperature of the winding and, consequently, an increase in its active resistance. As a result, an increase in the temperature (resistance) of the winding leads to an increase in losses due to the creation of a magnetic field, which ultimately leads to a decrease in the efficiency (efficiency) and in service life of the induction EMN.

Known electromagnetic induction pump [Anisimov AM and other atomic energy. - 2012. - T.112. - Issue 6. - S.362,], in which a heat shield is installed to reduce the heating of the winding. The disadvantage of such a pump is that currents similar to currents in the working medium (pumped liquid metal) will also be induced in such a screen, which also leads to a decrease in the efficiency and service life.

Known adopted for the prototype electromagnetic induction pump with an electromagnetic screen [Application of MHD devices in metallurgy / Ed. V.N. Timofeeva, E.A. Golovenko, E.V. Kuznetsova. - Krasnoyarsk: Siberian Federal University, 2007. - P.253], which is a sector of a hollow circular cylinder with an opening angle R. The advantage of this design is the reliability of the induction electromagnetic drive and the ease of controlling the speed of rotation of the screen.

The disadvantage of such a pump is that eddy currents caused by the difference in electric potentials under opposite poles will also be induced and shorted in such a screen, which also leads to a decrease in the efficiency and service life.

The claimed technical solution is aimed at eliminating the above disadvantages inherent in the analogue and prototype.

The technical result of the proposed solution is to increase the efficiency and service life of induction electromagnetic pumps.

The specified technical result is achieved due to the fact that in an electromagnetic induction pump containing a heat shield located between the inductor and the channel, characterized by the average diameter D, the longitudinal axis of the channel, the sides and the active length of the inductor, the number of pole pairs p, pole divisions τ, in order to increase the efficiency and operating life of the electromagnetic pump, the heat shield is made in the form of a k-lead-in (s) spiral (s), the cut line of which (s) forms an angle of inclination to the longitudinal axis of the channel α, where k is a positive integer.

In the designs of induction EMF with a heat shield made in the form of k-lead-in (s) spiral (s) (hereinafter in the form of a spiral), the cut line of which (s) forms an angle of inclination to the longitudinal axis of the channel, the following phenomena occur. The magnitude of the eddy current in the heat shield of such pumps is determined, ceteris paribus, by the difference of neighboring potentials and the resistance for the eddy current circuits. In induction EMCs of the CLLIN type, when the screen is made in the form of a spiral, firstly, the difference in neighboring potentials is crushed (reduced) along the longitudinal axis of the pump, and secondly, the length (extension) of the eddy current circuits increases. Each of these phenomena ultimately leads to a decrease in the magnitude of eddy currents, and, consequently, to a decrease in losses, a decrease in the temperature of the screen, i.e., windings and, ultimately, an increase in the efficiency and service life of induction EMNs of the Zlin type.

In an induction EMN of the VIN type, when the screen is made in the form of a spiral, an increase in length (extension) and a narrowing of the eddy current circuits occur. Thus, the electrical resistance for them increases, which ultimately leads to a decrease in the eddy currents and, consequently, to a decrease in losses, a decrease in the temperature of the screen, that is, the winding, and ultimately an increase in the efficiency and resource of induction electromagnetic waves of the VIN type.

The angle of inclination to the longitudinal axis of the channel α is determined by the formula:

, $$\alpha =arctg\frac{n\pi D}{2p\tau }$$

,

where n is the number of full revolutions of the section around the longitudinal axis of the channel.

The width of each elementary spiral t _s is determined by the formula:

, $$t_{\mathrm{from}}=\frac{l}{k}$$

,

where l is the length of the channel in the direction of its longitudinal axis, k is the number of elementary spirals.

Figure 1 shows a longitudinal section of a cylindrical linear induction pump, and figure 2 is a longitudinal section of a screw induction pump. The pumps contain a magnetic circuit (1), a winding (2), a channel in the form of an annular gap (3) (in a VIN type EMN with partitions made in the form of a helix), a core (4), a heat shield (5), contactors (6) (only EMN type VIN). In the same drawings, arrows indicate vectors: magnetic field induction - B; speeds - u; current density in liquid metal - j.

Figure 3, as an example, shows a screen made in the form of a single start spiral.

An electromagnetic induction pump operates as follows.

When the channel (3) is filled with liquid metal and voltage is applied to the winding (2), a current flows through it, under the influence of which a radially directed magnetic field is excited in the annular gap of the channel (3), which induces a current in the liquid metal. As a result of the interaction of the induced current with the magnetic field, an electromagnetic force arises that moves the liquid metal. Similar phenomena occur in the heat shield (5). At the same time, in the CLIN type EMC when the screen is made in the form of a spiral according to the claimed technical solution, the difference in the neighboring potentials along the longitudinal axis of the pump decreases and the length of the eddy current circuits increases, which ultimately leads to a decrease in the eddy currents and, consequently, to a decrease in losses and to a decrease temperature of the screen, that is, the winding, and ultimately to the achievement of the claimed technical result, namely increasing the efficiency and service life of induction EMNs of the type Tslin.

At the same time, in the VIN type EMC, when the screen is made in the form of a spiral according to the claimed technical solution, an increase in the length and narrowing of the eddy current circuits occurs. As a result, the electrical resistance for them increases, which ultimately leads to a decrease in the eddy currents and, consequently, to a decrease in losses, a decrease in the temperature of the screen, that is, the winding, and ultimately to an increase in the efficiency and service life of induction electromagnetic waves of the VIN type.

Claims (4)

1. An electromagnetic induction pump comprising a heat shield located between the inductor and the channel, characterized by the average diameter D, the longitudinal axis of the channel, the sides and the active length of the inductor, the number of pole pairs p, pole divisions τ, characterized in that in order to increase the efficiency and the operating life of the electromagnetic pump, the heat shield is made in the form of k-helix (s), the cut line of which (s) forms the angle of inclination α to the longitudinal axis of the channel, where k is a positive integer. 2. The electromagnetic pump according to claim 1, characterized in that the angle of inclination of the cut to the longitudinal axis of the channel α is determined by the formula
$$\alpha =arctg\frac{n\pi D}{2p\tau }$$

,
where n is the number of full revolutions of the section around the longitudinal axis of the channel. 3. The electromagnetic induction pump according to claim 1, characterized in that the electromagnetic pump is a cylindrical linear induction electromagnetic pump. 4. The electromagnetic induction pump according to claim 1, characterized in that the electromagnetic pump is a screw induction electromagnetic pump.

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