Working principle of intercooler
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.
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. Elephant.
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.
The intercooler is an accessory to turbocharging, and its function
is to improve the efficiency of air exchange of the engine. 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, and
because this radiator is located between the engine and the supercharger, it is
also called an intercooler.
The role of the intercooler is to cool the pressurized air out of
the supercharger. After the air passes through the supercharger, the pressure
increases and the temperature rises. The temperature of the pressurized air can
be reduced by the intercooler cooling, so as to improve the air density and
improve the inflation efficiency, so as to achieve the purpose of improving the
engine power and reducing emissions
Effect
The function of the intercooler is to reduce the intake temperature
of the engine. So why lower the intake temperature?
(1) The temperature of the exhaust gas from the engine is very high, and
the heat conduction through the supercharger will increase the temperature of
the intake air. Moreover, the density of the air will increase in the process
of being compressed, which also leads to the increase in the temperature of the
air discharged by the supercharger, which increases with the air pressure, but
the oxygen density decreases, thus affecting the effective inflation 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.
(2) 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.
(3) Reduce engine fuel consumption.
(4) Improve the adaptability to altitude. 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.
(5) Improve booster matching and adaptability.
Operating principle
With a well-designed intercooler, you can get an extra 5%-10% of
power.
There are also some cars using an overhead intercooler, through the
opening on the engine cover to get cooling air, so before the car starts, the
intercooler will only be affected by some hot air blowing from the engine
compartment, although the heat dissipation efficiency is affected, but because
the intake temperature will rise in such a case, so the engine's fuel
consumption will decrease a lot. This also indirectly reduces the working
efficiency of the engine, but for a powerful supercharged car, the unstable
start caused by too much power will be alleviated in this case, and the Impreza
car series of Subaru is a typical overhead intercooler. In addition, the
biggest advantage of the overhead intercooler layout is that it can effectively
shorten the travel of compressed gas to the engine.
External 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.
Internal cleaning inspection
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.
