Transformer Oil Coolers
Transformer oil coolers are Heat Exchangers used to cool the dielectric oil in a transformer. The cooling medium is naturally air or water. Transformer designers, rather than heat exchanger manufacturers, drove the evolution of transformer oil coolers, so the approach or terminology is slightly different than typical heat exchangers applications.
Transformers that experience lower loads can operate without pumps. The oil is circulated naturally by the flow that develops as a result of the density change due to the temperature change in the oil. As the oil is heated up from the losses in the core and windings, it becomes less dense and rises to the top of the transformer. If the cooler is located at the top of the transformer, the cooled oil becomes more dense and is piped down into the bottom of the transformer. As that oil passes over the core and windings it is again heated, and the process continues.
The air cooled oil coolers are designed to dissipate heat from the oil of generator Transformer, Distribution Transformer, Smoothing Reactors and Locomotive Transformers. Specially designed internal turbulators are provided for effective heat transfer from the viscous oil. The transformer oil coolers are built using aluminium finned tubes for better thermal transfer.