How it works – Intercooler

As you may know, an intercooler is a mechanical device used to cool a fluid, including liquids or gases, between two stages of heating process.

The intercoolers used in automotive industry use as an air-to-air or air-to-liquid cooler for forced induction, turbocharged or supercharged, internal combustion engines to improve volumetric efficiency by increasing intake air charge density. The intercoolers are used in many other applications, for the same reason.

Air-to-air Intercoolers

The high temperature of the intake air into the engine affect engine performance, consumption and emissions. To eliminate this disadvantage was used an intercooler system to cool the compressed air. So, the turbocharger take the cool air from outside, helped by the exhaust gases, and as the air compresses you will have an increase of temperature. Also, it takes a little bit of heat from the exhaust side of the turbocharger…and you don’t want hot air to go inside the combustion chamber.

Here is where the intercooler comes in. An air-to-air intercooler uses the air from outside to “wash” the surface of the intercooler, to cool down the hot compressed air that comes from the turbocharger through the piping. So, from hot compressed air you will have cool compressed air which will go to your intake manifold.

Air-to-water Intercoolers

At this type of intercooler, the working principle is exactly the same as that of a cooling radiator for the liquid inside the motor, with the difference that this one uses water to cool the intake air charge.
So, the turbocharger takes the air from outside, compresses the air, increases the air temperature and than is send to the combustion chamber. Here is the difference. Before it goes inside the combustion chamber, the air passes a heat exchanger with a water channel inside which is mounted inside the intake manifold.

The radiator in front of the vehicle is washed by the ambient air which cools down the water inside. This cooled water is transported through a circuit with a pump direct to the heat exchanger mounted inside the intake manifold. So, in this way, the air from the turbocharger is cooled by going through this heat exchanger and then it goes to the combustion chamber.

Few advantages of intercoolers:

• increased density of intake air into the engine, which has the effect of increasing engine power by up to 25% compared to the version without intermediate cooling.
• reducing thermal stress on the turbine and engine cylinders duw to lower temperature
• reduce fuel consuption by up to 5% compared to the version without intermediate cooling especially due to high  efficiency cooling at low speeds

Feel free to comment if you have something to add.