Transformer OFAF Oil Cooler For Large Transformers

For large power transformers, Forced Oil Air Forced (OFAF) cooling is the go-to solution for managing high heat loads efficiently.

How OFAF Cooling Works
Unlike simpler methods that rely on natural circulation, an OFAF system actively pumps oil and uses fans to force air over the coolers . This process involves:

Forced Oil Circulation: Oil pumps draw hot oil from the top of the transformer tank and push it through external coolers .

Forced Air Cooling: Fans blow air at high velocity over the cooler's finned coils to rapidly dissipate heat .

Continuous Cycle: The cooled oil is then returned to the bottom of the transformer tank to absorb more heat from the core and windings.

To ensure reliability, engineering specifications typically require redundancy, including a standby fan and oil pump for each radiator bank .

Because large transformers are critical assets, OFAF systems are designed with high redundancy. Industry standards and procurement specifications usually mandate:

Fail-Safe Operation: The transformer must be able to operate at 50% of its rated load for a continuous period with all cooling systems out of service .

Automatic Changeover: The cooler control system must automatically switch from the main power supply to a standby auxiliary supply if the main supply fails .

Alarm Systems: Coolers are required to have alarms for "No Oil Flow," "Fan Failure," and "Pump Failure" to alert operators of cooling problems .

Design Variations & Environmental Adaptability
VRCooler offer high flexibility to adapt OFAF coolers to specific site constraints:

Configurations: Units can be built with 1 to 4 fans (bays) and 1 to 5 oil passes .

Mounting: They can be mounted directly on the transformer tank or in remote installations (horizontal/vertical) .

Extreme Conditions: Options exist for ambient temperatures as low as -45°C and as high as +60°C, making them suitable for harsh desert or arctic environments .