Turbocharger is powered by exhaust gases from engine, its means turbocharger get the power from exhaust gases whereas all superchargers get the power from pulley or engine belt. It is used for regaining energy from waste gases at exhaust. It increase the power output for compressing more air into cylinder.
It consist two housings;
- Exhaust housing and
- Compressor housing
Exhaust Housing has the turbine wheel, when Exhaust gases directly strikes at turbine get start rotating by heat energy converted into kinetic energy. Turbine wheel connect with compressor of same shaft so compressor also start rotating automatically. Exhaust housing made up of special material (NI RESIST) to resist high temperature of exhaust gases (temperature around 900°-1000°Celsius).
Compressor Housing has the compressor wheel, this will get rotation from turbine wheel and compressor sucks the air from outside environment. It means less pressurized air converted into high pressurized air due to compressor. Compressor wheel made up of INCONEL.
Middle Portion of Turbocharger:
Between Turbine and Compressor Housing, Shaft is the only way of connecting both wheels. This shaft made up of pure steel. Shaft only takes rotation with either bush or bearing. In turbocharger bearing construction is complex compared to bush, so bushes are having the oil seals at both ends on shaft. Bushes and shaft both are made up of metal so friction is more, to reduce the friction between them move oils (Turbo oil) are added in the device. To stop the oil leak of move oil (Turbo oil) oil seals are fixed at in front of bushes.
How Turbocharger Works?
- Turbocharger can start its process at high RPM around 1000-1200 rpm. And this is why because engine produces more exhaust smoke at high rpm; so that it can able to rotate turbine wheel while with low rpm it doesn’t have that much of rotational force which is required to turn the turbine wheel.
- Turbocharger is suitable for multi cylinder engines because single cylinder engine cannot produce that much of exhaust gas as the Multi cylinder engines.
- Compressor wheel get its rotation from turbine wheel, thus compressor wheel get starts sucking air from air filter through outside. The main work of compressor wheel is to send pressurized air into the intercooler. We may actually send air from compressor to directly at intake manifold after the compressor wheel. But air after the air filter has temperature around 45° Celsius which depends upon the outside atmosphere and due to compressor, this air temperature increased up to 200° Celsius.
- We know that the air density of high temperature is less as compare to cold air. That’s why to cool down the air; intercooler plays the major role for turbocharger. Air density of less temperature air is high that’s means more air molecules means more oxygen to burn fuel for high explosion in combustion chamber. So, intercooler decreases air temperature for more air molecules.
It has the maximum rpm 2.5 Lakh-3 Lakh/minute, by crossing its limit an imbalance is created at shaft that breaks the oil seals and it can cause engine damage. To prevent this issue turbocharger is equipped with valve between two housing. At a particular high pressure, means pressure produced after 3 lakh rpm/min valve can automatically open up and it can divert the extra exhaust gas towards the silencer rather than the turbine wheel so that it can stop the crossing the limit of 3 lakh rpm/minute automatically.
Turbocharger is actually forcing the air in to cylinder, so by forcing additional air which is called boost. More air means more oxygen and can burn more fuel which can create greater explosion compare to normal combustion in cylinder. Piston moves very rapidly as compared to normal piston movement in normal engine. Without turbocharger it does not create this fast reciprocating motion in engine. At high reciprocating motion, piston force is high that can provide crankshaft greater turn. In transmission system engine crankshaft converts reciprocating motion of the piston into rotary motion then this motion drives the flywheel and drive shaft respectively. If this entire process runs at higher rotation, so it can produce more speed at vehicle differential. Effectively by increasing the explosion inside cylinder gives greater rotational force at wheels.
- Decrease in Emission.
- Increase in Horsepower.
- Does not require external power source to run turbocharger
- Turbo lag is the time between the demand for an increase in power and turbocharger providing increased intake pressure, and hence increased power. Turbo lag occurs because turbochargers rely on the buildup of exhaust gas pressure to drive the turbine. In simple words turbocharger is turned on after a particular amount of exhaust gas is produced which happens at a certain rpm. So when this threshold rpm is crossed the turbo does not instantly delivery requisite power surge or boost, and during this period the vehicle does not move very fast when the throttle is given or accelerated. This is due to the time needed for the exhaust system and turbocharger to generate the required boost. Load on the compressor, friction and inertia are main contributor for turbo lag.
- Space requirement is more.
In this article we have learnt about how turbocharger works in a internal combustion engine. If you find anything missing or incorrect than comment us. If you found this article informative than like and share it on Facebook and Google+.