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 usually use a "shell and tube" heat exchanger design, where the cooling water flows through the "tube core" in the center of the unit and the heat is pressurized
Air flows outside the tube set, transferring heat as it passes through the "housing" on the inside of the heat exchanger. After cooling, the air is discharged from the subcooler and fed through a pipeline to the engine combustion chamber.
Water-cooled intercoolers are precise-designed devices designed to deal with the high temperatures of compressed combustion air.
Intercoolers are usually only seen in cars with turbocharged cars. The intercooler is actually a part of the turbocharger, and its role is to improve the efficiency of the engine's air exchange. Whether it is a supercharged engine or a turbocharged engine, it is necessary to install an intercooler between the supercharger and the engine intake manifold, because the radiator is located between the engine and the supercharger, it is also called an intercooler, referred to as an intercooler.
Why do I need an intercooler
One of the reasons why turbocharged engines have more power than ordinary engines is that their air exchange efficiency is higher than the natural intake of ordinary engines. When the air enters the turbocharger, its temperature will rise significantly and its density will become lower. The intercooler plays the role of cooling the air, and the high-temperature air is cooled by the intercooler and then enters the engine. If the lack of intercooler and let the pressurized high temperature air directly into the engine, it will cause engine damage or even dead fire due to high air temperature.
Since the temperature of the exhaust gas from the engine is very high, the heat conduction through the supercharger will increase the temperature of the intake air. Moreover, the density of air will increase in the process of being compressed, which will inevitably lead to an increase in air temperature, thus affecting the efficiency of the engine. If you want to further improve the inflation efficiency, it is necessary to reduce the intake air temperature. Data show that under the same air-fuel ratio conditions, the engine power can be increased by 3% to 5% for every 10 ° C decrease in the temperature of charged air.
If the uncooled charged air enters the combustion chamber, in addition to affecting the inflation efficiency of the engine, it is easy to cause the engine combustion temperature to be too high, causing failures such as detonation, and will increase the content of NOx in the engine exhaust gas, causing air pollution. In order to solve the adverse effects caused by the heating of the air after supercharging, it is necessary to install an intercooler to reduce the intake temperature.
Due to the presence of the intercooler, the engine fuel consumption can be reduced and the adaptability to altitude can be improved. In high altitude areas, the use of intercooling can use a higher pressure ratio of the compressor, which makes the engine get more power, improve the adaptability of the car.
Intercooler classification
Intercoolers are generally made of aluminum alloy materials. According to the different cooling medium, common intercoolers can be divided into two types: air-cooled and water-cooled.
What is an engine intercooler
When people buy a car, they always talk about whether it's better to buy a naturally aspirated car or a turbocharged car. The reason for this problem is that turbocharged engines have more intercoolers than naturally aspirated engines, and the power is better. Intercooler is an important part of the supercharged engine, whether it is a mechanical supercharger or a turbocharged engine, you need to install an intercooler between the supercharger and the engine intake pipe, because the radiator is located between the engine and the supercharger, so it is also called the intercooler, referred to as the intercooler.
What is the role of the engine intercooler
Does the intercooler give heat to the intercooler? That would be a big mistake. If it is understood as cooling the air, it is not very accurate. Intercooler and supercharger are closely related to the two parts, the supercharger is compressed into the engine air, the intercooler as an air radiator, is to enter the engine pressure gas heat, reduce the temperature of the gas into the engine.
Turbocharged engines are more powerful than naturally aspirated engines because they rely on superchargers to increase the efficiency of air combustion. However, the existence of superchargers also brings problems. On the one hand, because the temperature of the exhaust gas from the engine is very high, the heat conduction through the supercharger will increase the temperature of the intake air. On the other hand, the density of air will increase in the process of being compressed, which will inevitably lead to an increase in air temperature, thus affecting the efficiency of the engine. If you want to further improve the inflation efficiency, it is necessary to reduce the intake air temperature. Data show that under the same air-fuel ratio conditions, the engine power can be increased by 3% to 5% for every 10 ° C decrease in the temperature of charged air. If the uncooled charged air enters the combustion chamber, in addition to affecting the intake efficiency of the engine, it is easy to cause the engine combustion temperature to be too high, resulting in detonation and other failures, so in order to solve the adverse effects of the air temperature rise after the pressurization, the intercooler must be added to cooperate with the pressurization system
Working principle of intercooler
Now that we know that the intercooler cools the pressurized gas, how does it dissipate heat? As one of the main components of the engine cooling system, the work of the intercooler is consistent with the efficacy of the whole engine cooling system. If the engine cooling system uses a mechanical fan to dissipate heat, the intercooler uses a mechanical fan to dissipate heat. Switching to hydraulic fans and electronic cooling fans is also the case. There is also an air circulation system in the intercooler. The outside air enters the air supercharger and enters the intercooler after supercharging. The intercooler uses the cooling chip and cooling fan to heat exchange the pressurized gas, that is, to cool down. When the temperature drops to 45°c, it will enter the engine gas chamber through the intercooler outlet. Some of the burned air re-enters the supercharger cycle, and some is dissipated with heat.
Problems existing in the work of intercooler
At present, the common commercial vehicle engine cooling system is to use a large fan for heat dissipation. A belt fan or a silicone clutch fan or an electromagnetic clutch fan dissipates heat from both the tank radiator and the intercooler. And because the water tank and the intercooler are arranged in series, as long as the water tank needs to dissipate heat, the intercooler will also be blown by the cold wind. However, sometimes the intercooler does not need cold air to blow. This is the "binary heat transfer" problem in the engine cooling system. For this problem, intelligent temperature control system can be used to solve it. For example, the engine intelligent cooling system ATS, the intercooler and the radiator are arranged in parallel, do not block each other, a separate temperature sensor monitors the water and gas temperature in real time, is equipped with an independent electronic fan for separate heat dissipation, and the air duct is not crossed. Details can be found at www.yilitek.cn.
Intercooler maintenance precautions
Exterior cleaning
Because the intercooler is installed in the front, the intercooler heat sink channel is often blocked by leaves, mud (hydraulic oil overflow in the steering tank), so that the heat dissipation of the intercooler is blocked, so it should be cleaned regularly. The method of cleaning is to use a water gun with not too high pressure to vertical Angle of the intercooler plane, top-down or bottom-up slow flushing, but must not be inclined to prevent damage to the intercooler. (Commercial vehicle intercooler cleaning method is the same)
Internal cleaning and inspection (disassembling and cleaning method)
The internal pipeline of the intercooler is often accompanied by mud, gum and other dirt, which not only Narrows the air flow channel, but also reduces the cooling heat exchange capacity, so it must also be maintained and cleaned. In general, every year or when the engine is overhauled and the tank is welded, the interior of the intercooler should be cleaned and inspected.
Cleaning method: Add an aqueous solution containing 2% soda ash (temperature should be 70-80 ° C) to the intercooler, fill it up, wait 15 minutes to see if the intercooler has leakage. If any, it should be dismantled, welded and repaired (same as repairing the water tank); If there is no leakage, shake back and forth, repeat several times, pour out the lotion, and then fill in a clean water solution containing 2% soda ash for washing until it is relatively clean, and then add clean hot water (80-90 ° C) to clean until the released water is clean. If the outside of the intercooler is stained with oil, it can also be cleaned with alkali water. The method is: soak the oil in lye and remove it with a brush until it is clean. After cleaning, dry the water in the intercooler with compressed air or dry it naturally, or start the engine without connecting the intercooler and the engine connection pipe when installing the intercooler, and then connect the engine intake pipe when there is no water at the air outlet of the intercooler. If it is found that the core of the intercooler is seriously dirty, the air filter and the intake pipes should be carefully checked where there is a leak, and the fault should be removed.
