What are the cooling methods of dry-type transformer?
Writer： Hengfeng you electric Time：2023-04-18 views：times
There are two cooling methods for dry-type transformer, one is natural air cooling (an) and the other is forced air cooling (AF).
In case of natural air cooling, the transformer can operate continuously for a long time under the rated capacity. When forced air cooling, the output capacity of the transformer can be increased by 50%. It is applicable to intermittent overload operation or emergency accident overload operation; As the load loss and impedance voltage increase greatly during overload, it is in non economic operation state, so it shall not be in continuous overload operation for a long time.
Dry type transformers are widely used in local lighting, high-rise buildings, airports, docks, CNC mechanical equipment and other places. In short, dry-type transformers refer to transformers whose iron core and winding are not immersed in insulating oil.
Main forms:
1. Open type: it is a common form. Its body is in direct contact with the atmosphere. It is suitable for relatively dry and clean rooms (when the ambient temperature is 20 ℃, the relative humidity shall not exceed 85%). Generally, there are two cooling modes: air self cooling and air cooling.
2. Closed type: the device is located in a closed shell and is not in direct contact with the atmosphere (it is mainly used for mining and belongs to explosion-proof type due to poor sealing and heat dissipation conditions).
3. Casting type: epoxy resin or other resin is used as the main insulation. It has simple structure and small volume. It is suitable for transformers with small capacity.
characteristic:
1. Safe, fire-proof, pollution-free, and can operate directly in the load center;
2. It adopts domestic advanced technology, with high mechanical strength, strong short-circuit resistance, small partial discharge, good thermal stability, high reliability and long service life;
3. Low loss, low noise, obvious energy-saving effect and maintenance free;
4. Good heat dissipation performance and strong overload capacity. When forced air cooling, it can improve the capacity of operation;
5. Good moisture resistance, suitable for operation in high humidity and other harsh environments;
6. Dry type transformer can be equipped with perfect temperature detection and protection system. Intelligent signal temperature control system is adopted, which can automatically detect and tour display the respective working temperature of three-phase winding, automatically start and stop the fan, and have alarm, trip and other function settings;
7. Small size, light weight, less floor space and low installation cost.
