Transformer Air-cooled Oil Cooler

Transformer air-cooled oil cooler is a kind of equipment used to cool transformer oil. It takes away the heat in the transformer oil through air convection, so as to reduce the temperature of the transformer and ensure the normal operation of the transformer.

Transformer air-cooled oil cooler is mainly composed of cooling fan, heat sink or radiator. When the transformer is running, the heat generated by the iron core and windings will increase the temperature of the transformer oil. The hot oil will rise and come into contact with the heat sink or radiator, the cooling fan will blow air over the heat sink, accelerate the air convection, so that the heat of the hot oil is emitted to the surrounding air, and the cooled oil will be returned to the transformer again, so on and so forth, to achieve the continuous cooling of the transformer.

According to the size of transformer capacity and actual demand, air-cooled oil cooler has different application methods:

Oil-immersed self-cooling type: there is no special cooling equipment for the cooling system, the oil circulates naturally in the transformer, and the heat emitted from the iron core and windings relies on the convection effect of the oil to be transmitted to the wall of the oil tank or the radiator.

According to the size of the transformer capacity, can be divided into three different structures, such as the capacity of a very small transformer with a smooth box wall; capacity of a slightly larger transformer using a smooth box wall welded to some of the heat-sinking tendons of the way; capacity of some of the larger transformer in the tank outside the installation of a number of radiators. This cooling method is simple in structure and high in reliability, and is widely used in transformers with a capacity of less than 10,000 kVA.

Oil-immersed air-cooled: in the transformer tank next to each radiator installation of a fan to several fans, the natural convection of the air to change the role of forced convection, in order to enhance the radiator's ability to dissipate heat. It is compared with the self-cooling system, the cooling effect can be increased by 150% to 200%, equivalent to the transformer output capacity increased by 20% to 40%. When the load is small, the fan can be stopped so that the transformer to self-cooling mode of operation, when the load exceeds a certain value (such as 70% of the rated load), the fan can be automatically put into operation. This type of cooling is widely used for medium-capacity transformers above 10,000 kVA.

In practice, in order to ensure the normal operation of the transformer air-cooled oil cooler, it is necessary to carry out regular inspection and maintenance, which mainly includes checking whether the fan is functioning normally, whether the heat sink is clean, and whether there is any leakage of the oil pipe. At the same time, it is also necessary to pay attention to the environment around the cooler to ensure good ventilation and avoid debris blocking the cooling channel.

Air-cooled oil cooler has the advantages of relatively simple installation and maintenance, no additional cooling medium, but the cooling effect may be subject to certain limitations of the ambient temperature and air circulation. In some large capacity or higher cooling requirements of the transformer, other cooling methods may be used, such as forced oil circulation air-cooled or forced oil circulation water-cooled.