SU1161997A1 - Tank for testing transformer radiators - Google Patents

Abstract

TANK FOR TRANSFORMER RADIATORS, filled with insulating liquid, is preferable. Transformer oil containing tubes for connecting test radiators, electric heaters, thermal insulation, temperature control devices distributed over the height of the tank, drain pipe, characterized in that, in order to improve the accuracy of heat flux of radiators, it is equipped with one another. At a certain distance, the batteries are located one above the other chambers, in their upper part there are holes, through which they communicate with the tank, and in the lower part of the chambers are installed electr The heaters, the chambers are filled with insulators (with liquid of liquid up to the level of the holes with the formation of an air prog puff between the mirror of the insulating liquid and the lid of the chamber and separated from one another vertically by an air gap; the horizontal chambers are interconnected by branch pipes with

Description

11 The invention relates to electrical engineering, in particular to devices for thermal testing of radiators used to cool power transformers, in which the tanks are filled with various dielectric fluids that simultaneously play the role of electrically insulating media and heat transfer media. It is known that transformers are sometimes used for heat testing radiators. However, such tests are fraught with great inconvenience and cost, since they require the use of equipment, test fields, factory test station personnel and the assembly shop and do not guarantee at the same time the required accuracy of the test results due to the relatively large heat flux of the transformer tanks themselves and insufficient accuracy of measurement of the amount of heat released by the active part of the transformer. A heating tank is known for testing radiators containing sockets for connecting test radiators, sockets for filling it with transformer oil, oil level indicators, thermal insulation, electrical heaters and thermocouples for measuring the temperature of the oil. The power of the heater is regulated by a potential regulator. Heat losses of the heating tank, reduced by thermal insulation, make it possible to determine more accurately the dependence of the heat flux of the radiators under test on the temperature difference between the oil and air. In this heating tank, the electric heaters are located at several levels and their heating surfaces, in which the oil heats and rises upward, they are separated by horizontal layers of oil, interrupting the resulting upward oil flow, which is why {for each trough of heaters it begins to form anew. In addition, the flow of the ascending fluid moving on the surfaces of the heaters depends on the perimeter of their horizontal cross section, just as the downward flow moving along the internal cooling surfaces of the radiators depends on their perimeter in the horizontal cross section. This leads to the fact that the flow of circulating fluid, in this case, transformer oil, depends on the design of electric heaters, the distance between them and the horizontal perimeter of their surfaces, and the results of tests of radiators on tanks with different designs of electric heaters that are not comparable in value flows. Uncertainty in the results leads to an increase in the recommended number of radiators, i.e. to waste materials, labor and funds. The aim of the invention is to improve the accuracy of determining the heat fluxes of radiators. The goal is achieved by the fact that a tank for testing transformer radiators filled with insulating liquid, mainly transformer oil, containing connections for connecting test radiators, electric heaters, thermal insulation, temperature control devices distributed over the height of the tank, a drain pipe, are provided with spacers from the Other, at a certain distance, there are batteries of cells arranged one above the other, in their upper part there are holes, through which they communicate with the tank, and bottom of cameras installed heaters, chambers are filled with insulating liquid to the openings to form a layer of air between the mirror interlayer insulating fluid and chamber lid and separated from one another by an air gap vertically, horizontally disposed chambers are interconnected and are connected to spigots drain pipes. The continuity of the vertical surfaces of the battery contributes to the formation of a stable fluid flow, which increases with an increase in the thickness of the boundary layer along the surfaces of the batteries, and the presence of several batteries allows changing the horizontal perimeter of the batteries by including their appropriate number to establish the necessary fluid flow.

Separating batteries into several chambers placed one above the other, insulated in their upper part by air gaps located above the O1, through which the chambers communicate with the tank space, allows to carry out experiments on heating oil in the tank at different heights with respect to the radiator, which also affects radiator heat dissipation.

FIG. 1 shows the proposed tank, a longitudinal vertical section; in fig. 2 shows section A-A in FIG. one; in fig. 3 is a section b-B in FIG. 2

The tank for testing transformer radiators is made in the form of a tank that has a bottom 1 (Fig. 1 and 3), walls 2 (Fig. 1-3), a wall 3 and is covered with thermal insulation 4, 5 and 6. The tank is filled with liquid 7 , a branch pipe 8 is attached to the bottom of the tank 1. An overflow pipe 9 is mounted in the tank, the lower end of which is passed through the bottom of 1 tank, thermocouples 10 are attached to the overflow pipe 9 along its entire height. The bundle 11 of thermocouples 10 is brought out of the heating tank to the outside of the measuring device (not shown. The tank is mounted on stands 12 and equipped with nozzles 13 for connecting the test radiator 14, Electric heaters 15 are placed in the lower part of chambers 16 and fixed on wall 2 of the tank using flange connections 17. The flange connections 17 are thermally insulated with removable insulating lining 18. The chambers 16 of the electric heaters are filled with the same liquid 7 as the tank, up to the hole 19 with a diameter of 5-10 mm in the upper part of the chambers 16. Above the holes 19 in each The chamber 16. forms an air-insulating heat-insulating layer 20. All chambers 16 communicate with the inner space of the tank by means of holes 19. Each chamber 16 of one battery is separated from the chamber 16 located under it with a roof-top 21.,

The chambers 16 of adjacent batteries, located on the same level, are interconnected through: through the holes 22 and the nozzles 23 (Fig. 2 and 3). From chambers 16 of one of the extreme batteries, drain pipes 24 are carried out with stop valves 25 at the ends. Nipple

8 is provided with stop valves 26 at the end.

The level indicator 27 of the liquid 7 in the tank is connected to the internal space of the tank by means of an opening 28 (FIG. 1), protected from damage and thermally insulated by a flap 29 of transparent material, such as thick glass.

Thermocouples 30 are mounted into the wall 2. The lid 3 and the bottom 1 (Figs. 2 and 3) of the tank. The 3 pins are connected to the flange 31, the junction is sealed by a gasket 32. The ends of the drain pipes 24 with the stop valves 25 are insulated with detachable insulation 33.

The tank is filled and drained from the tank through a pipe with stop valves 26. Through the overflow pipe 9, the tank communicates with the atmosphere, so that it is protected from possible deformation of the thermal expansion of the liquid and when it is filled with a liquid with increased pressure.

Nozzles 23 and tubes 24 with shut-off valves 25 allow the chambers 16 to be filled with liquid 7 to the level of the holes 19. Between the holes 19 and located -. No. 1 above them with covers 21 When the chambers 16 are filled with liquid 7, an air gap 20 is formed and further maintained, which insulates this chamber 16 from the same chamber above it.

The air gap 20 allows thermally separating the chambers with the heaters 15 turned on about the chambers with the heaters turned off for conducting experiments with different relative positions of the chambers 16 with the heaters turned on and the radiator 14, which also affects the circulation rate of the liquid and the thermal flow radiators.

Using the tubes 24, the liquid can be drained from the chambers 16 if it is necessary to replace the heaters 15 and carry out repairs.

The economic effect of the implementation of the proposed invention cannot be directly calculated, but obtaining reliable data on the heat fluxes of radiators will provide an opportunity

511619976

Designing cooling systems and coprostatic surfaces by 5% will reduce the available stock of heat-saving materials on summed surfaces. Reduction of heat - 213 thousand rubles.

355-6 30

Claims (1)

TANK FOR TESTING TRANSFORMER RADIATORS, filled with insulating liquid, mainly. transformer oil containing pipes for connecting the tested radiators, electric heaters, thermal insulation, temperature control means distributed over the height of the tank, a drain pipe, characterized in that, in order to increase the accuracy of determining the heat fluxes of radiators, it is equipped with spaced apart from one another the distance from the batteries from the chambers located one above the other, holes are made in their upper part through which they communicate with the tank, and electronically installed in the lower part of the chambers ers, the insulating liquid filled chamber to a level of holes to form an air prog, puffs insulating fluid between the mirror and the chamber lid and separated from one another by an air gap vertically, horizontally disposed chambers are interconnected and are connected to spigots drain pipes. SU., - 1161997> f 1161