Common applications for oil coolers include torque converters, hydraulic and transmission oil cooling in addition to engine oil and compressor oil cooling and waste heat recovery. Engines in vehicles involved with industrial towing or other heavy-duty items have engine oil coolers. For engine oils in particular, maintaining a moderate oil temperature is important as oil functions both as a lubricant and a coolant.
If the oils get too hot the horsepower will drop and the oil will begin to break down, damaging the performance of the engine as the oil is no longer able to provide its lubricating properties. This could result in engine seizure or failure. Oil coolers are used in a wide range of industries such as machine tool, automotive, aerospace, construction, industrial, commercial, chemical processing and electronics.
Additional oils that are typically cooled in oil cooler processes include lubricating oils, transformer oils, quenching oils. There are two main types of oil coolers: hydraulic oil coolers and oil air coolers. Hydraulic oil coolers are typically a shell and tube design in which metal wall partitions, known as a tube wall or plate, act as conductors between the two fluids.
Hot oil flows on one side of the barrier and transfers its heat to cooler oils flowing on the other side. Thermal energy only flows from the hotter to the cooler in an attempt to reach equilibrium. The surface area of these partitions affects speed and efficiency: the larger the surface area of a partition, the faster and more efficient the heat transfer. Oil air coolers are typically a plate, plate and frame or flat plate design in which heat is transferred continuously from heated oil to air without adding energy to the process.
The basic concept of an oil air cooler is that the heated oil flows on one side of a thin corrugated metal plate while the comparatively cooler air is on the other; the plate enables the easy transference of heat between the oil to the air. Oil air coolers require less floor space compared to other types of oil cooler equipment and is lighter-weight.