Intercoolers (also known as charge air coolers) increase the combustion efficiency of engines equipped with forced air intake (turbochargers or superchargers), thereby increasing engine power, performance and fuel efficiency.
A turbocharger compresses the intake combustion air, increasing its internal energy but also raising its temperature. Hot air is less dense than cold air, which makes it burn less efficiently.
However, by installing an intercooler between the turbocharger and the engine, the inlet compressed air is cooled before it reaches the engine, thus restoring its density and bringing optimum combustion performance.
The intercooler, as a heat exchanger, can discharge the heat generated during the compressor gas process of the turbocharger. It accomplishes this heat transfer step by transferring heat to another cooling medium, usually air or water.
Air cooled (also known as blast type) intercooler
In the automotive industry, the increasing demand for more efficient engines with lower emissions has led many manufacturers to develop smaller capacity turbocharged engines to achieve the ideal combination of engine performance and fuel efficiency.
In most automotive installations, air-cooled intercoolers can provide sufficient cooling and work much like car radiators. When the vehicle moves forward, the cooler ambient air is drawn into the intercooler and then through the heat sink, transferring the heat from the turbocharged air to the cooler ambient air.
Water cooled intercooler
In environments where air cooling is not applicable, water-cooled intercoolers are a very effective solution. Water-cooled intercoolers typically use a "shell and tube" heat exchanger design, where cooling water flows through a "tube core" in the center of the unit, while hot charged air flows outside the tube set, transferring heat as it flows through the "shell" inside the heat exchanger. After cooling, the air is discharged from the subcooler and fed through a pipeline to the engine combustion chamber.
The role and working principle of automotive intercooler:
The role of the automotive intercooler is mainly reflected in the following five aspects:
1, reduce the engine intake temperature. The reduction of the intake temperature can improve the engine inflation efficiency, thus improving the engine's power performance.
2, reduce engine fuel consumption. By improving the engine inflation efficiency, each drop of fuel and air form a good combustible mixture, so as to achieve full combustion of fuel.
3, the role of cooling air. The intercooler can cool the high-temperature air before entering the engine to avoid problems such as detonation and flameout caused by the high-temperature air directly entering the engine.
4, adapt to high altitude working environment. By increasing the inflation efficiency, the engine can maintain a stable power output at high altitudes.
5. Improve the air exchange efficiency of the turbocharged engine.
In order to reduce the intake air temperature, the role of the intercooler is mainly reflected in the following aspects:
1. Reduce the conduction effect of exhaust gas on intake air temperature. The high temperature of the exhaust gas will cause the intake air temperature to rise, affecting the engine inflation efficiency.
2, avoid uncooled charged air into the combustion chamber resulting in detonation and waste gas pollution.
The addition of intercooler can solve the adverse effects of air heating after supercharging.
In addition, the intercooler can also reduce engine fuel consumption, improve the adaptability to the high-altitude environment, and improve the matching and adaptability of the supercharger.
An automotive intercooler is a gas radiator that is wrapped around a pipe. The air flows inside the intercooler, which absorbs heat and cools the air out.
Automotive intercooler is a gas radiator, the interior of the intercooler is surrounded by pipes, the gas is blown in from one end, the gas is blown in the internal pipeline flow in the intercooler, in the flow process the gas heat is absorbed by the intercooler, the cooled gas flows out from the other end, many people think that this is to cool the turbocharger. Actually not, the intercooler is to cool the pressurized air. There are two main types of intercoolers for turbocharged engines, one is air-cooled and the other is water-cooled.
Why cool the added air?
Because the temperature of the supercharger itself is very high, coupled with the temperature of the air after compression will further increase, so the air temperature after the turbocharger can easily break through 100 degrees Celsius. After the air temperature rises, the density will decrease, and the oxygen content will naturally decrease together, so that the oxygen in the cylinder is less, which will inevitably affect the performance. And the intake temperature is too high and easy to produce knock, so the supercharged engine needs to cool the pressurized air.
The air-cooled intercooler is located at the front, in simple terms, it is an ordinary radiator, and the airflow flowing through the front during driving impacts the air cooler to achieve heat dissipation of the intake air. Because the air temperature is low and the air flow is large during driving, the heat dissipation effect of the air-cooled intercooler is very good. In addition, the structure is relatively simple and the cost is lower.
However, the air flow pipeline of the air-cooled intercooler is too long, and the air needs to go from the supercharger through the pipeline to the front, and then through the pipeline to the throttle after cooling, which will aggravate the turbine hysteria. Moreover, the smaller the displacement and the lower the speed, the more obvious the impact, so in the early days, when people were not too sensitive to turbine hysteresis, many cars used air-cooled intercoolers. In addition, the air-cooled intercooler at low speed because there is not enough air flow, the heat dissipation effect will decrease.
Water-cooled intercoolers are cooled by engine coolant, and the pipe length can be shorter, which can reduce turbine hysteresis. And the coolant circulation is stable, do not worry about the cooling effect at low speed.
However, the water-cooled intercooler costs more, and because the temperature of the coolant is not low when the hot car is hot, the overall cooling effect is not as good as the air-cooled type.
The intercooler is used to cool the supercharger out of the pressurized air, the air after the supercharger, the pressure increases, the temperature rises, through the intercooler cooling can reduce the temperature of the pressurized air, so as to improve the air density, improve the inflation efficiency, in order to achieve the purpose of improving the diesel engine power and reducing emissions.
The intercooler is part of the pressurization system. When the air is compressed at a high proportion, it will produce high heat, which will reduce the expansion density of the air, and at the same time, it will cause damage to the engine temperature. In order to obtain higher volumetric efficiency, the high-temperature air needs to be cooled before injection into the cylinder.
This requires the installation of a radiator, the principle is similar to the radiator of the water tank, the high temperature and high pressure air is dispersed into many small pipes, and there is room temperature air flowing at high speed outside the pipe, so as to achieve the purpose of cooling. Because this radiator is located between the engine and the turbocharger, it is also called the central cooler, referred to as the intercooler.
About the role of the car intercooler:
1. Improve engine power performance. The lower intake temperature makes the engine inflation efficiency increase, so the engine power performance can be improved.
2, reduce engine fuel consumption. The engine inflation efficiency is improved so that every drop of fuel can form a good combustible mixture with the air, and every drop of fuel is fully burned.
3, reduce the possibility of engine deflagration. High temperature and high pressure air and fuel form high temperature and high pressure combustible mixture gas, which is easy to deflagration in the engine cylinder. Reducing the intake temperature can effectively restrain the deflagration of the engine. Deflagration can cause the engine to shake abnormally and damage engine accessories.
4, better adapt to the high altitude working environment. High altitude oxygen content is low, improve the inflation efficiency so that the engine power can be sustained output.
The function of the intercooler is to reduce the intake temperature of the engine. Generally made of aluminum alloy material. According to the different cooling medium, common intercoolers can be divided into two types: air-cooled and water-cooled.
(1) The air-cooled type uses outside air to cool the air passing through the intercooler. The advantage is that the entire cooling system has fewer components, and the structure is relatively simple than 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 pipeline and the air passing resistance is larger. Air-cooled intercoolers have been widely used because of their simple structure and low manufacturing cost. Most turbocharged engines use air-cooled intercoolers, such as the engines of Huatraca TCI off-road vehicles and FAW-Volkswagen Bora 1.8T cars.
(2) Water cooling uses circulating cooling water to cool the air through the intercooler. The advantage is that the cooling efficiency is higher, and the installation position is more flexible, there is no need to use a long connection pipe, making the entire intake pipe more smooth. The disadvantage is that it requires a circulating water system that is relatively independent of the engine cooling system, so the entire system has more components, higher manufacturing costs, and a complex structure. The application of water-cooled intercoolers is relatively rare, generally used in vehicles with engines in the middle or rear, and on large-displacement engines, such as the Mercedes-Benz S400 CDI car and Audi A8 TDI car equipped with engines that use water-cooled intercoolers.