How does the automotive intercooler work?

The function of the intercooler is to lower the inlet temperature of the engine. Generally made of aluminum alloy. According to the different cooling medium, the common intercooler can be divided into two types: air-cooled and water-cooled.

(1) air-cooled air is used to cool the air passing through the intercooler. The advantage is that the whole cooling system has fewer components and the structure is simpler than that of the water-cooled intercooler. The disadvantage is that the cooling efficiency is lower than that of the water-cooled intercooler, which generally requires a longer connection line, and the air resistance is greater. Air-cooled intercooler has been widely used because of its simple structure and low manufacturing cost. Most turbocharged engines use air-cooled intercooler, such as the engines of huataitra TCI off-road vehicle and faw-volkswagen bora 1.8t car.

(2) water cooling system USES circulating cooling water to cool the air passing through the intercooler. The advantages are higher cooling efficiency and more flexible installation position, which eliminates the need to use a very long connection line, making the whole inlet line more smooth. The disadvantage is that it needs a relatively independent circulating water system and engine cooling system to cooperate with it, so the whole system has many components, high manufacturing cost and complicated structure. Water-cooled intercoolers are rarely used. They are generally used in mid-engine or rear-engine vehicles, as well as in large-displacement engines. For example, the engines of mercedes-benz S400 CDI and audi A8 TDI both use water-cooled intercoolers. The intercooler is used to cool the supercharged air from the supercharger. After the supercharger passes through the air, the pressure increases and the temperature rises. Cooling through the intercooler can reduce the temperature of the supercharged air, thus improving the air density and charging efficiency, so as to achieve the purpose of improving the power of the diesel engine and reducing the emission.

Intercooler: part of the supercharging system. When the air is compressed in a high proportion, it will generate a high amount of heat, which will reduce the expansion density of the air. At the same time, it will make the engine temperature too high and cause damage. To achieve higher volume efficiency, it is necessary to cool the hot air before injecting it into the cylinder. This requires the addition of a radiator, similar to a radiator in a water tank, which disperses high temperature and pressure air into many small pipes, and outside the pipes there is room temperature air flowing at high speed to achieve cooling purposes (the gas temperature can be reduced from 150 degrees Celsius to about 50 degrees Celsius). Since this radiator is located between the engine and the turbocharger, it is also called the central cooler, or intercooler for short.

The temperature of the exhaust gas directly discharged by the engine is usually as high as 8 or 9 baidu, which will cause the turbine body and inlet temperature to rise. In addition, work is done during the compression of air, so the pressurized compressed gas into the cylinder may overheat and cause pre-combustion of gasoline and knock, affecting the power output. The heat is also an invisible killer of engines. Therefore, supercharged engines usually introduce intercoolers to lower the inlet temperature. Generally speaking, the intake temperature of 50 ~ 60 degrees can be reduced (off the critical value) after the use of intercooling, which can appropriately increase the engine compression ratio and improve the power output at low speed. At the same time, due to the density of cold air, this design can improve the intake density of the engine under the same conditions, so the engine is more efficient.