RU113066U1 - POWER TRANSFORMER EXPLOSION PREVENTION DEVICE - Google Patents

Abstract

1. A device for preventing explosion of a power transformer containing a decompression chamber located outside the transformer tank and a bursting disc, while the decompression chamber is made in the form of a collapsible package of heat-resistant cloth and is fixed to the outer flange of the bursting disc. ! 2. The device according to claim 1, characterized in that it comprises a mesh fence of the expanding decompression chamber attached to the outer flange of the bursting disc. ! 3. A device according to any one of claims 1 and 2, characterized in that the heat-resistant fabric is made of woven tape or bundles with armide threads. ! 4. A device according to any one of claims 1 and 2, characterized in that the heat-resistant fabric is made of carbonized carbon fibers.

Description

The proposed utility model relates to the field of electrical engineering and can be used to prevent rupture of the housing of structural elements, mainly transformers, cooled by a large volume of liquid (oil). In the event of a short circuit and an arc arising in the active part of the transformer, a large amount of gas is generated during decomposition of the transformer oil. Basically, it is acetylene and hydrogen, which, at high temperature, in contact with air spontaneously ignites, which leads to a fire and serious accidents. The process develops within tens of milliseconds, while the pressure in the tank rises sharply, exceeding critical parameters. Dealing with the consequences of such accidents requires a significant investment in equipment recovery. Therefore, protection of the transformer against explosion requires special attention.

In transformer technology, a protective fire system is known that is driven by various relay type sensors. The disadvantage of these devices is their inertia - the response time is hundredths of a second, which is many times higher than the necessary protection response speed, since the process develops within a few milliseconds (Lizunov S.D., Lokhanin A.K. Power transformers. Reference book. Energy Publishing House, 2004). Therefore, to protect transformers from explosion and destruction, systems with less inertia are needed.

Closest to the proposed solution (its prototype) is a device for preventing the explosion of electrical transformers (patent RU 2263989 from 03/17/2000). This device comprises a decompression chamber connected to the tank by a pipeline on which a bursting device (membrane) is located. Such systems are used to protect transformers of medium and high power. However, the rate of gas evolution when an arc occurs in the oil is extremely high (up to 50 m ³ / s). Therefore, the pressure gradients in the tank and pipelines connecting the tank to the decompression chamber are too large to reduce the pressure in the tank to a safe level in time. Due to the greater pressure drop in the pipeline, the prototype device is not efficient enough and often does not work in severe accidents of powerful transformers.

The proposed device eliminates the disadvantages of the prototype, solving the technical problem of protecting the transformer using a decompression device with virtually no piping connecting the tank to the decompression chamber.

The stated technical problem is solved in that in a device for preventing the explosion of a power transformer, containing a decompression chamber located outside the transformer tank and a bursting membrane, the decompression chamber is made in the form of a folding bag of heat-resistant fabric and is mounted on the outer flange of the bursting membrane.

The specified set of features provides a quick release of pressure in the tank during a short circuit (short circuit). The resulting gases and oil are discharged into the chamber, which opens as products enter it.

A utility model has been developed in that the device comprises a mesh guard of a expandable decompression chamber mounted on the outer flange of the bursting disc. This removes mechanical stress from the camera.

Another development of the utility model is the embodiment of a heat-resistant cloth decompression chamber (from woven tape or bundles with armide threads, or carbonized with carbon fibers).

The essence of the proposed solution is illustrated by the circuit shown in figure 1. The device comprises a decompression chamber 1 located outside the transformer tank 2, and a bursting disk 3. The chamber 1 is made in the form of a folding bag of heat-resistant fabric and is mounted on the outer flange 4 of the bursting membrane 3.

The device operates as follows.

The transformer contains an active part, placed in the tank 2, filled with coolant (dielectric oil). In the upper part of the tank 2 under the cover there is a short pipe on which a bursting element (membrane) 3 is mounted, fixed by two flanges. Chamber 1 is mounted on the outer flange 4. When hot products of transformer oil decompose in the active part as a result of a short circuit in the opening chamber 1, a simultaneous pressure release occurs in the tank 2, which prevents the tank body from breaking. In the decompression chamber 1, gaseous products (hydrogen, acetylene, CO) are separated from the oil. Gases, forming in the upper part of the tank, under pressure enter through the pipeline outside the transformer compartment, where, upon contact with air, gases ignite and burn out 5, without causing harm to the equipment.

To remove mechanical loads, the chamber 1, when opened, rests on a mesh fence-basket 6. In the lower part of the tank of the expanding chamber 1 there is a pipe with a valve 7 for draining the cooled oil after burning gaseous decomposition products. The valve 8 installed on the pipe in front of the membrane 3 is closed after the pressure is released, thereby preventing the return of the decomposition products of oil to the tank 2. The valve 9, installed at the outlet of the pipeline 10, is closed after the combustion of gaseous products.

The heat-resistant cloth can be made of woven tape or bundles with armid threads. At the heart of the canvas are compounds of carbon and oxygen. Higher parameters for heat resistance have graphite - fabric cloths (RU 2318932 from 2006). They withstand temperatures of 1200-2000 ° C.

Cloth carbonized by carbon fibers, can be used to form thermal protection (RU 2257429). After carbonization, the web is subjected to processing at 1200-2800 ° C.

In the proposed utility model, there is no delay in the time of pressure relief in the transformer tank, since there are no pipelines connecting. tank with a decompression chamber, which increases the effectiveness of the protective device. In this case, the device is compact (tissue camera 3 in the normal state is folded into a bag).

Claims (4)

1. A device for preventing the explosion of a power transformer, containing a decompression chamber located outside the transformer tank, and a bursting membrane, wherein the decompression chamber is made in the form of a folding bag of heat-resistant fabric and is mounted on the outer flange of the bursting membrane. 2. The device according to claim 1, characterized in that it contains a mesh fence opening a decompression chamber, mounted on the outer flange of the bursting disc. 3. The device according to any one of claims 1 and 2, characterized in that the heat-resistant fabric is made of woven tape or bundles with armid threads. 4. The device according to any one of claims 1 and 2, characterized in that the heat-resistant fabric is made of carbonized carbon fibers.