RU136230U1 - DISCONNECTOR WITH AUTONOMOUS LIQUID COOLING - Google Patents

Abstract

Disconnector with autonomous liquid cooling, including base, fixed contacts, movable contacts (knives) in the form of hollow copper busbars with water cooling channels, insulators, radiators with distributors, radiator tubes, fittings, connecting tubes, piston type pressure sensors, emergency microswitches characterized in that the radiators are located on the site, mounted on insulators located on fixed contacts, in the contact areas of the fixed contacts and movable contacts s (knives) electrically conductive pastes and greases are used, while the length and surface area of the radiators are increased and the radiators are placed parallel to the stationary contacts.

Description

The device relates to electrical engineering, in particular, to high-current apparatus engineering and can be used in the development of high-current switches and disconnectors.

Known disconnector type RVK-20/12000 with natural cooling for 12 LLC amperes (Filippov Yu.A. Development of designs and studies of disconnectors for rated currents 12000-14000 A. - Sat. "High-voltage apparatus", edited by prof. V.V. Afanasyev, "Energy", 1969, p. 173-181.)

Seven support insulators and one rotary insulator, which serves as an element of the disconnector drive, are installed on the steel welded base. Between the insulators and the base there is a duralumin sheet used as part of the screen when installing the disconnector in a closed conductor, which significantly reduces the heating of the base from exposure to an electromagnetic field. On insulators fixed fixed detachable contact and fixed one-piece contact, towards which the knife goes when disconnecting the disconnector. The box-shaped fixed structure is formed of four corners and four plates between them. The corners and plates of both fixed contacts are made of copper sheet and are mounted on steel welded contact holders. The knife of the disconnector is made of eight identical tires having a channel-shaped profile in cross sections with the shelves outward, two on each of the four sides of the fixed contacts. The predetermined orientation of the knife tires relative to each other and relative to the fixed contacts is achieved using a welded fixed box, which, in turn, is oriented relative to the fixed contact by means of adjustable rollers mounted on the inner walls of the contact holder.

The disadvantages of this apparatus are: limitation of the rated current, high consumption of non-ferrous (copper) and precious (silver) metals, relatively low reliability and a limited lifetime.

Known disconnector type RVP (3) -20/12500 with autonomous liquid cooling for a rated current of 24,000 Amps (Shalaginov Α.Α., Belyaev V.L. Patent No. 124433, Disconnector with autonomous liquid cooling, 2013.) ·

By design, the disconnector has a base, fixed contacts, movable contacts (knives) in the form of hollow copper busbars with water cooling channels, insulators, a platform (base), radiators with distributors, radiator tubes, fittings, connecting tubes, piston type pressure sensors, microswitches emergency alarm.

The disadvantages of this apparatus are: limitation of the rated current, relatively uneven distribution of current across the moving contacts (knives) and low reliability and limited service life due to the fact that the radiators are mechanically connected to the moving contacts (knives) and during the switching process (on-off) radiators move simultaneously with the movable contacts, that is, the movable contacts carry an additional mechanical load, which reduces the reliability of operation, reduces the service life and AET isolator design more complicated.

The purpose of the utility model is: increasing the rated current, improving the distribution of the rated current across the moving contacts (knives), simplifying the design, increasing the reliability of operation and increasing the life of the device.

This goal is achieved by the fact that the disconnector has radiators located on the site fixed on insulators on fixed contacts (thereby removing radiators from the movable contacts (knives) and completely removing the additional mechanical load on the movable contacts - knives), they have fixed and movable contacts in places the contact of movable contacts (knives) and the fixed contacts of electrically conductive paste and grease, which will increase the contact area, reduce and stabilize the transition resistance (Resistance to contraction) and to make the distribution of the moving rated current contacts (blades) more uniform, and the length and area of the cooling surfaces of the radiator are increased, and the radiators are placed parallel to the fixed contacts.

A General view of the disconnector with self-contained liquid cooling is shown in Figure 1. Here, the box-shaped conducting conductor forms two fixed contacts 1 and 2 mounted on insulators, interconnected by four movable contact knives 3 with silver brazing, using electrically conductive pastes and greases 4. These knives 3 are made of hollow copper bars with channels for water cooling. They are interconnected by tubes 5. Above the apparatus there are two radiators 6 and 7 located on the site 8, mounted on insulators 9, 10 and 11, 12 mounted on fixed contacts 1 and 2. The whole system is filled with coolant. Heating of the liquid begins in knives located on the bottom surface of the disconnector. Then it passes through the knives located on the sides of the device, and enters one part of the radiator. The cooled liquid flows from its other end and enters the contact blades on the horizontal side of the apparatus. This creates a closed loop.

To improve the conditions of fluid movement, the circulation loop is shaped so that over its entire part there are no areas where the fluid had to go down or go up. Each radiator section consists of five brass tubes 13 finned with copper wire, sealed at their ends in distributors 14, which are rectangular boxes made of stainless steel. They have a fitting 15 for connecting to the apparatus and holes for filling liquid, closed with metal plugs. To protect the system from excessive pressure increase during vaporization, a piston-type pressure sensor is installed in the upper part of the distributor, which acts on the emergency micro-switch. Inside the distributors 13 partitions are installed, allowing you to use the desired number of parallel connected tubes 12 of the radiator 5.

Figure 2 shows a diagram of the autonomous cooling of the movable contacts on one side of the disconnector. Mobile contacts - knives 3, 4 - electrically conductive pastes and greases, connecting hoses 5 and radiator 6.

The disconnector operates as follows: (Figure 2). When you turn on the movable contacts 3 on the disconnector is the load current. The liquid inside the hollow movable contacts 3 is heated, its density decreases, and it rises up into the radiator 6. Cold liquid with a higher density is lowered from the radiator to contacts 3. There is a convective heat exchange between contacts 3 and radiator 6, in which the liquid is cooled. As a result, a more intensive selection of heat losses from the contact system of the disconnector occurs, its temperature decreases, and the load current through the disconnector can be increased. In this case, due to the presence of electrically conductive pastes and lubricants 4 in the contact zone, a more uniform distribution of current across the movable contacts (knives) 3 is ensured.

The technical and economic effect of the proposed technical solution consists in:

1. The increase in the rated current which is achieved by placing radiators 6 and 7 on the platform 8 mounted on insulators 9, 10 and 11, 12 located on fixed contacts 1 and 2 (instead of placing on moving contacts (knives) 3);

2. The increase in the rated current, which is achieved by using in the places of contact of movable contacts (knives) 3 and fixed contacts 1 and 2 of electrically conductive pastes and greases 4, which will increase the contact area, reduce and stabilize the contact transition resistance (pulling resistance) and thereby the distribution of the rated current across the moving contacts (knives) 3 is more uniform;

3. Improving the reliability of the disconnector, which is achieved by placing radiators 6 and 7 on the site 8 mounted on insulators 9, 10 and 11, 12 located on fixed contacts 1 and 2 (instead of placing on moving contacts (knives) 3);

4. Simplification of the design of the apparatus, which is achieved by placing radiators 6 and 7 on the site 8 mounted on insulators 9, 10 and 11, 12 located on fixed contacts 1 and 2 instead of being placed on moving contacts (knives) 3);

5. The increase in the service life, which is achieved by placing radiators 6 and 7 on the platform 8 mounted on insulators 9, 10 and 11, 12 located on fixed contacts 1 and 2 and using movable contacts (knives) 3 and fixed contacts 1 and 2 in places of contact electrically conductive pastes and greases 4, which will increase the contact area, improve the transition resistance (pulling resistance) and thereby improve the distribution of the rated current across the moving contacts (knives) 3 and make it more uniform;

6. An increase in the service life, which is also achieved by lowering the temperature of heating the water at the radiator outlet by more than 10 ° C, due to the increase in the length and surface of the radiators and the longer cooling time of the liquid while passing through the radiators located horizontally (the liquid velocity decreases).

Claims (1)

Disconnector with autonomous liquid cooling, including base, fixed contacts, movable contacts (knives) in the form of hollow copper busbars with water cooling channels, insulators, radiators with distributors, radiator tubes, fittings, connecting tubes, piston type pressure sensors, emergency microswitches characterized in that the radiators are located on the site, mounted on insulators located on fixed contacts, in the contact areas of the fixed contacts and movable contacts s (knives) electrically conductive pastes and greases are used, while the length and surface area of the radiators are increased and the radiators are placed parallel to the stationary contacts.

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