DD148687A1 - HIGH VOLTAGE UNIT WITH LIQUID INSULATING AND THERMOELECTRIC AIR DRYER - Google Patents

Abstract

The invention relates to a Hochspannungsgeraet with liquid insulating agent, in particular Grosztransformator, at the Ausgleichsgefaesz (conservator), a thermoelectric air dryer is connected. The aim is to increase the efficiency of the thermoelectric air dryer by constantly adding warm damp insulating oil to the equalizing vessel to intensify the drying process of the insulating oil. This is achieved in that between the Ausgleichsgefaesz and the lower portion of the equipment container a downpipe with a non-return flap, preferably double back flap, is arranged. Furthermore shut-off valves are provided at the ends of the Falleitung.

Description

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Title of the invention

High voltage device with liquid insulating medium and therraoelectric air dryer

Field of application of the invention

The invention relates to a high-voltage device with liquid insulating means, in particular large transformer, at the equalization vessel (conservator), a thermoelectric air dryer is connected.

Characteristic of the known technical solutions

It is known to equip oil transformers with thermoelectric air dryers (DE-OS 1 488 839, DD 134 407), which not only dehumidify the fresh air entering the air space of the expansion vessel, probe beyond deprive the insulating liquid and the insulation moisture caused by aging phenomena the insulating material is created. The air dryers are flanged to the conservator by means of pipes. · In the dry process, warm, moist air enters the dryer through the upper pipe socket, which is directly connected to the air cushion above the insulating oil. The humidity is frozen out and settles as ice on the radiator surfaces. The cold dried air falls down, enters the conservator in the lower pipe socket, is heated in the lower pipe, which is surrounded by the insulating oil, and rises in the air cushion and re-accumulates with moisture of the air cushion. Then the cycle begins again. Heating the air causes cooling

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of the insulating oil In the conservator. The exchange of cool, dry insulating oil of the conservator with the warm, damp insulating oil of the transformer boiler is very slow топ because the cold falling and the warm rising insulating oil flows through a pipe, in which the Buchholz relay resides, and thus obstructs each other. As a result, the drying process takes place only slowly over months or years. During this period, the high-voltage device is unnecessarily loaded with moisture and the insulating oil is negatively affected.

Object of the invention

The aim of the invention is to increase the effectiveness of the connected thermoelectric air dryer.

Explanation of the essence of the invention

The invention has for its object to provide an arrangement through which constantly and unhindered warm moist insulating oil can ascend via the expansion line to the conservator.

This is achieved by arranging a downpipe with a non-return flap, preferably a double check flap, between the conservator and the lower region of the device container.

It is expedient to provide a shut-off valve at the ends of the down pipe for control purposes. · Although oil driers for transformers have long been known in which a pipe is also arranged between the equalizing tank (conservator) and the apparatus vessel (transformer tank) (eg. DE-OS 2 257 615, 2 500 950) · However, this line is used to connect the actual drying device for the oil, eg. B. a Yakuum spray system. In these facilities, therefore, in contrast to systems with thermoelectric air dryers, the oil itself is circulated through the drying device, so that hler is based on a completely different objective.

Dte invention has the advantage that the cold dry insulating oil from, the bottom of the conservator, is led directly to the container bottom, so that unhindered «poor, moist insulating oil rises above the expansion line to the conservator. To quickly transport moisture into the conservator, it rises into the air cushion and can be frozen out with the air dryer. There is thus a much faster and more effective drying than before. Furthermore, the intake area of air dryers is widened, i. H. it can be used with the invention air dryer for endangered and smaller transformers and for relatively dry and stored insulating oils · The check valve prevents interference with the arranged in the expansion pipe Buchholzschutzes; it ensures that when pressure waves occur in the device vessel no insulating oil can be pressed in the opposite direction through the downpipe and the Buchholz relay can be bypassed. Rising gases thus always pass through the expansion pipe and the Buchholz relay. During its checks, the functionality of the non-return valve can also be checked by means of the shut-off valves.

exemplary

The detailed explanation is based on a schematic diagram. By means of a drop line 1, the cold insulating oil, which is up to about half the height of the conservator 2 and is particularly concentrated at the cold air outlet 3 of the air dryer 4, discharged into the bottom 5 of the device container 10. The heated in the device ebehälter 10 insulating oil rises above the expansion line 6, in which the Buchholzrelais 7 is in the conservator 2 on. For shut-off in the event of leaks and during checks, two shut-off valves 8 and 9 are provided. Backflows in the case of pressure waves in the device container 10 are prevented by a double non-return valve 11.

Claims (2)

invention claim 1. High-voltage device with liquid insulating agent, in particular large transformer, at the equalization tank, a thermoelectric air dryer is connected, characterized in that between the expansion tank (2) and the lower portion of the equipment container (10) a Palleitung (1) with a check valve, preferably double check valve OO , is arranged. 2. High-voltage device according to item 1, characterized in that at both ends of the Palleitung (1) shut-off valves (8; 9) are provided See drawings!