Heat Exchanger Used in the Engine Oil Circuit:
The heat exchanger of the oil circuit ensures that when an engine is just started (and not yet at operating temperature), the oil heats up more quickly. The coolant warms up relatively fast, but the engine oil usually takes twice as long until it reaches the same temperature of about 90 degrees. By using a heat exchanger, the (warm) coolant flows in the housing right next to the (cold) engine oil, which consequently is heated up.
When the engine has been at operating temperature for a significant time and is heavily loaded, the temperature of the engine oil shoots up to over 100 degrees. Due to the functioning of the heat exchanger, the opposite effect now occurs: the constant coolant temperature of 90 degrees now cools down the engine oil as much as possible. This is why this component is called a heat exchanger: One time it heats the engine oil, the other time it cools the oil.
The image below shows a heat exchanger of the engine oil circuit. This is often also referred to as the oil cooler. However, this is not entirely correct, because with a cold engine, the oil here is actually heated up. The 2 hoses mounted to the housing are coolant hoses. The coolant circulates in the round housing. On this side of the housing, the oil filter is mounted. This oil filter covers the entire front of this housing. The hole on the inside is the supply of engine oil to the filter, and from the small holes on the outside, the engine oil is fed back into the engine block.
Other Applications with a Heat Exchanger:
Not only is the engine oil brought to temperature using a heat exchanger. Many other components in the car also operate with this principle:
- Radiator: The radiator is also considered a heat exchanger; the coolant temperature is transferred to the passing air.
- Heater Core: The cabin air flows through the heater core. It has a temperature of around 90 degrees and thus heats the cabin air.
- A/C Condenser: The warm R134a is cooled by the condenser, as (just like with the radiator) the wind flows through it.
- A/C Evaporator: The warm outside air flows through the evaporator and is significantly cooled before being blown into the interior.
- EGR Cooler: The exhaust gases that are fed back to the engine through the EGR are cooled by the coolant.
- Intercooler: The compressed air from the turbo flows through the intercooler and is then cooled by the outside air before it goes to the engine intake.