Why transformers are often oil-immersed instead of dry-type

The main reasons why transformers use oil-immersed designs instead of dry-type designs are as follows:
1. Heat dissipation performance: The oil-immersed transformer has good heat dissipation performance and can operate stably under high load conditions. In contrast, dry-type transformers have relatively weak heat dissipation performance.
2. Cost: The manufacturing cost of oil-immersed transformer is low, but the operation and maintenance cost is high; Whereas, dry-type transformers have higher manufacturing costs, but lower operation and maintenance costs.
3. Safety: Dry-type transformers have a lower fire risk and are more suitable for crowded places; Oil-immersed transformers, on the other hand, have a relatively high risk of fire.
4. Environmental protection: dry-type transformers do not need to use insulating oil, and there is no leakage and environmental pollution problems; Oil-immersed transformers, on the other hand, may have a risk of leakage and have a certain impact on the environment.
5. Capacity: The capacity of oil-immersed transformers is larger than that of dry-type transformers.
6. Application scenario: Dry-type transformers are used in underground floors, floors and crowded fields, while oil-immersed transformers are used in independent substations.
In summary, while dry-type transformers have some advantages, such as low fire risk and environmental friendliness, oil-immersed transformers have advantages in terms of heat dissipation performance, manufacturing cost, and capacity, and are more suitable for use in some application scenarios. Therefore, when selecting a transformer, it is necessary to choose the appropriate design type according to the specific use conditions and needs.