SU674615A1 - Magnetohydrodynamic choke - Google Patents

Description

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This invention relates to devices for controlling the flow rate of electrically conductive media. The choke can be used to control the flow rate (velocity) of electrically conductive heat transfer agents in nuclear power engineering, for example, in liquid metal circuits of nuclear power plants with fast neutron reactors, in installations for transporting and distributing liquid metals, and for other technological purposes.

The magnetohydrodynamic (MHD) device is known. The main nodes of which are the metal tract (channel), windings, the magnetic system l. This device works in the flow control mode (MHD droselsel) as follows. When an electrically conductive medium moves in a constant or alternating magnetic field. 8. It induces an emf under the action of which currents flow through the electrically conductive medium, depending on the channel design, along the electrically conductive medium, through special current locking devices (busbar 1M) or along the walls of the channel interaction

induced currents in an electrically conductive medium and a magnetic field causes braking of the moving medium. Flow control in such a device is carried out by varying the amount of electric current in the field winding.

In throttle mode, the most promising is the use of MHD devices,

For which for ideal currents the ideal short-circuit condition is met, i.e. grad 0. These devices include devices with channels.

5 of the annular section, the magnetic system and the excitation winding of which covers a metal tract with a cylindrical outer wall. ,

A significant disadvantage of such

Q MHD devices with natural cooling of the excitation winding by the liquid metal flowing in the metal tract is that, due to the different technological and structural gaps between the magnetic system and the metal tract, the magnetic system and the excitation winding, the excitation winding and the trash winding, the temperature of the excitation winding is always higher than the temperature of the liquid metal at 50-120C. This leads to the fact that already at the temperature of the liquid metal at 50120С lower than the permissible temperature of the winding wires, forced cooling (liquid or air) must be applied, which causes complications, decreases reliability and increases the cost of the device.

Also known MHD choke containing a metallotrakt with a cylindrical outer wall. The magnetic system and the excitation winding covering the u4j metallotract.

The disadvantage of this device with natural lm cooling of windings with liquid metal flowing in the metal tract and having a temperature Lower than the permafrost temperature, is that the existing cooling is not efficient enough when operating under normal conditions and practically does not allow operation under vacuum conditions.

The aim of the invention is to increase the cooling efficiency of the excitation winding with a liquid metal flowing in the metal tract and having a temperature lower than the permissible winding temperature.

This goal is achieved by the fact that the outer wall of the metal tract is provided with a number of metal ring elements, between which there is an excitation winding

the drawing shows the proposed MHD Choke. .

The MHD choke contains an annular cross-flow metal tract formed by an inner ferromagnetic core 1 and a cylindrical outer wall 2, an outer ring; a pin pipeline consisting of poles 3 and 4, ring elements 5, a winding 6. The ring elements are made of copper and are welded to the outer wall of the metal tract i.e. represent a whole with her. The winding is wound directly on the honey ring elements and compounded.

The proposed MHD choke works as follows.

A stream of liquid metal moves through the flowing metal tract. When current is applied to the excitation field in the Tgetallotract, located in the gap between the poles of the magnetic system and the internal ferromagnetic core, a radial magnetic field arises. The flow of liquid metal intersects the radial magnetic field, and in it under the action of EMF flow ring currents, the interaction of which with the magnetic field creates an electromagnetic force directed against the flow and 5 inhibits it. During the operation of the throttle, the field winding is heated and its heat losses through the ring elements are transferred to the liquid metal, and also partially (from the outer surface of the coil) to the environment.

Claims (4)

1. Author's certificate of the USSR 180313, cl. B 22 D 11/10, 1966. 2. The author's certificate of the USSR 290386, cl. And 02 N 4/20, 1971. 5 3, USSR Copyright Certificate No. 494835, Ll. H 02 N 4/20, 1975. 4. USSR author's certificate No. 550227, cl. B 22 D 11/10, 1977. x