How does an Intercooler work?
- Author: SPELAB Mechanical Engineer (focusing on car modification for 10 years)
An intercooler is a device used in turbocharged and supercharged engines to cool the compressed air that is forced into the engine. The compressed air is heated as it is compressed by a turbocharger or supercharger, and this can cause a decrease in the density of the air (reducing oxygen), which reduces the engine's power and efficiency. An intercooler works by dissipating this heat, which helps to increase the density of the air and improve engine performance by providing cool dense air to the engine for burning the fuel.
Science behind working of intercooler
As oxygen plays a crucial role in the combustion process, therefore, providing quality and quantity oxygen to the engine is an integral point in combustion process and therefore is deeply focused. We all know that, for fuel to burn completely, one must ensure the following
- Sufficient amount of air to completely burn the fuel
- Availability of denser air (cold air)
From school education we all know that:
Cool air is denser, which means it has greater concentration of Oxygen as compared to hot air. The ability of the engine to burn the fuel completely, increases with the amount of oxygen supplied to the combustion chamber.
However, if limited amount of oxygen is available in the chamber at the time of combustion, then it is obvious that all the fuel won’t be burnt. The unburnt fuel is considered a waste and consequently with improper burning we will lose power and it will also contribute towards environmental emissions. Therefore, we need to provide sufficient quantity of oxygen to the engine for proper burning and eventually for better performance from the engine. The intercooler is a heat exchanger which cools the hot air and provide engine with cool dense air so that we can have better combustion.
How does an Intercooler work?
An intercooler is typically located between the turbo or supercharger and the engine, and it is connected to the intake system. The compressed air from the turbo or supercharger flows through the intercooler, where it is cooled by the surrounding air. The intercooler is usually made of aluminum or another heat-conductive material, which helps to dissipate the heat from the compressed air.
Following are two main types of intercoolers, based on their working.
- Air to air intercooler
- Air to water intercooler
Air to air intercooler
These intercoolers use air to cool air. These are the most common type of intercoolers and use the ambient air to cool the compressed air. Its works similar to the radiator of the engine. Air cooled intercoolers works by directing compressed air past a number of cooling fins and via a maze of tiny tubes. These cooling fins absorb heat from the hot compressed air, which is then quickly cooled by air coming from outside the driving vehicle.
Air to water intercoolers
As the name suggests, this intercooler cools the compressed air with the help of water. Cool water is pumped through the unit from one side and air from another side. After the water extracts the heat from the air, air is ready to be fed to the intake manifold, whereas, that water has to be cooled now. For cooling this heated water, it passes either through the radiator or some cooling circuit before it enters again the intercooler. For even better cooling characteristics, one can change the water with some other liquid which has better heat absorbing capabilities like the coolants we have in our radiators.
These intercoolers are smaller in size because of the fact that water conducts heat better than air and is therefore suitable for a variety of temperatures. However, the increased complexity, cost and weight makes them less favorable for vehicles.
An intercooler is an important part of a turbocharged or supercharged engine because it helps to increase the density of the air that is forced into the engine. This results in more oxygen available for combustion, which in turn results in more power and efficiency. Additionally, it also helps to reduce emissions by reducing the amount of heat that is generated during the combustion process.
It is important to note that an intercooler can be damaged by high temperatures, so it is important to keep the intercooler in good working condition. Proper maintenance, such as cleaning and inspecting the intercooler regularly, can help to prevent damage and ensure that it is working correctly.