Why put pebbles under the transformer? Why water?
Writer： Hengfeng you electric Time：2023-04-07 views：times
We can often see that a lot of pebbles are placed under some transformers, so what are these pebbles used for? Is it just for aesthetics?
Why put pebbles under the transformer? What's under the cobblestone? Why is there water?
Oil-immersed transformers use oil as the main insulating means of the transformer and rely on oil as the cooling medium, such as oil-immersed self-cooling, oil-immersed air-cooled, oil-immersed water-cooled and forced oil circulation. The main components of the transformer are iron core, winding, oil tank, oil pillow, respirator, explosion-proof pipe (pressure relief valve), radiator, insulating sleeve, tap changer, gas relay, thermometer, oil purifier, etc.
Compared with dry-type transformers, oil-immersed transformers have the characteristics of low cost and convenient maintenance, which can solve the problems of large-capacity heat dissipation and high-voltage insulation of transformers. However, since the cooling oil of the oil-immersed transformer is flammable, this leads to the inherent disadvantage of the oil-immersed transformer, that is, it is flammable and explosive.
Why put pebbles under the transformer? What's under the cobblestone? Why is there water?
At this time, a series of ingredients appeared, such as pebbles;
The part below the transformer is often called the unloading sump or unloading sump (or something similar), which leads to the accident oil sump or accident sump.
If an accident occurs, such as oil injection or explosion, the oil of the transformer will be discharged into the oil discharge pit, and then flow into the accident oil pool.
Some pools are made with grilles, some are not. For grids, pebbles are placed on the grid; for those without grids, pebbles are placed in the drain pit. Whether to set up a barrier is related to the type, capacity and voltage level of the transformer, and there are relevant regulations.
Why put pebbles under the transformer? What's under the cobblestone? Why is there water?
When placing pebbles under an oil-immersed transformer, the following seven factors are mainly considered:
1. After the transformer is used for a long time, the parts may have problems such as aging and leakage. Placing a large number of pebbles can absorb the oil leakage of the transformer, so that the transformer oil can be returned to the accident oil pool smoothly and reduce the occurrence of accidents;
2. In the event of an accident, the cobblestone can prevent the oil in the transformer from splashing and avoid explosion.
3. In the event of an explosion or fire, the cobblestone plays a role in isolation, preventing the fire from spreading to the ground, which is conducive to extinguishing the fire.
4. The cooling effect is slight. When the temperature of the transformer is too high, it can be cooled with pebbles.
5. Cobblestone insulation is convenient for operators to maintain and inspect.
6. Cobblestones have a shock absorption effect. Its function is the same as the stone on the railway, which can add a buffer layer.
7. Prevent weeds from growing.
Why put pebbles under the transformer? What's under the cobblestone? Why is there water?
Why put pebbles under the transformer? Why have water?
#Fire regulations have clear requirements:
1. When the single oil volume of outdoor transformers and other oil-immersed electrical equipment exceeds 1000kg, oil storage pits and oil discharge facilities should be set up.
2. The capacity of the oil storage pit should be determined according to the capacity of 100% equipment oil or 20% equipment oil. When the oil storage pit is set at 20% of the oil volume of the equipment, an oil discharge pipe should be set at the bottom of the pit to discharge the accident oil into the accident oil storage pit. The inner diameter of the oil discharge pipe should not be less than 100mm, and the oil should be quickly discharged in the event of an accident, and the pipe mouth should be equipped with an iron mesh filter.
3. The oil storage pit should be set with grids, and the net spacing of the grids should not exceed 40mm. The upper part of the grid is laid with pebbles, the thickness of the pebbles is not less than 250mm, and the particle size of the pebbles is 50-80mm.
When setting the accident total oil pool, the volume of the accident total oil pool should be determined according to the total oil volume of the maximum oil-filled electrical equipment. When installing a fixed water spray fire extinguishing device, the total volume of the accident oil pool should also consider the amount of water spray, and leave a certain margin.
