The turbocharger is explained along with basic details, definition, purpose, components, working principle, advantages, disadvantages, etc.
A comparison between turbocharger vs supercharger is also captured.
Let’s learn Turbocharger!
Let’s try to understand the basics of turbochargers. The engine efficiency and power is the most critical aspect of any automobile vehicle.
There are various advancements and tries done to improve engine efficiency and power.
Two of them are supercharging and turbocharging. They were known in the same terms as “Turbosupercharger” back in the days, but now they are known separately as,
There is a significant difference between these two in their construction as well as working.
In 1905, Alfred Buchi working at Gebruder Sulzer considered as the birth of turbocharger. The patent was patented with the radial engine and axial flow turbine.
In normal engines or naturally aspirated engines, injection happens by multi-point fuel injections and works normally at lower pressure.
Naturally aspirated engines, has the following problems,
Now, these are the problems so,
Now, to avert all the problem, the turbocharger is introduced in the engine and it helps,
But if we use a bigger engine, there are more problems with the weight and overall efficiency of an automobile vehicle.
By keeping the engine’s size the same, you can increase its power and efficiency by sending more air to get more fuel-air mixture and increase the power by Turbocharging. It helps,
We will see in the details about the turbocharger used in automobiles: their working, parts, and the difference with superchargers, etc.
Turbocharging differs from supercharging in lots of ways, from working mechanisms to parts.
Let’s know more about the different parts of turbochargers.
There are a few main components of turbocharger and these are as follows,
Let’s learn all these turbocharger parts in brief,
A turbocharger is having a casing where all other parts are mounted. Refer Fig. 3
Now we know the exhaust gases are passed on to the turbine to drive the compressor. The turbine spins at very high speed (250000 RPM).
The performance of the turbocharger is closely related with the turbine size. Large turbochargers need more heat and pressure to spin which cause the lag at the start of the engine.
Similarly, the smaller turbochargers need less heat and pressure to spin but can’t get the performance and acceleration compared to large turbochargers. To avoid this the twin-turbo designs are employed.
Twin-turbo as the name suggests it has two turbochargers arranged in series or parallel arrangements.
In parallel arrangements, the turbochargers get half-half exhaust gas power. Whereas in sequential turbochargers, one of them runs at low speed and the other at a fixed speed according to load.
Instead of using the one large turbine twin-turbo design is used.
This design has two exhaust gas inlets and two nozzles. One of them is smaller and useful for the quick response, other one is the larger one used to gain the peak performance.
Generally, a centrifugal compressor is used in turbocharging.
It has the impeller and construction same as used in the centrifugal supercharger. But in turbocharging, the compressor will be powered up by the turbine that moves with the help of exhaust gases.
The compressor gets the fresh air and transfers the fresh to the engine manifold.
This hub has the shaft which connects the compressor, impeller and the turbine.
It also consists of bearing systems (thrust bearing or ball bearing) to allow the shaft to rotate at high speed with less friction.
Let’s the working principle of a turbocharger,
We know already the objective of the turbocharger is to improve the volumetric efficiency of the engine by increasing the density of the intake gas.
The exhaust gases are passed on to the turbine.
As we have seen in the above section, differently designed turbines can be used in turbochargers.
The compressor impeller starts to rotate and creates low pressure which helps to induce fresh air through a filter.
This air is compressed and its pressure and temperature are increased.
We have already learned the parts and working principle, let’s see a simple diagram based on our understanding,
There is one more use of turbochargers in automobile vehicles.
Because of using the wasted energy, the fuel can be burned to its highest possible efficiency and thus the fuel efficiency can be increased.
A simple schematics is include below to have a clear concept on oveall system,
Turbochargers are classified into two types based on geometry. These are,
Let’s learn the basic concept of both types of turbochargers.
Variable geometry turbocharger (VGT) (also known as variable-nozzle turbines or VNT) means as the name suggests, it varies the aspect ratio of the turbocharger based on the conditions.
There may be two situations for aspect ratio:
The above conditions creates problems like,
Hence, the aspect ratio needs to be optimized and this Variable geometry charger (VGT) helps to do this.
Let’s see how VGT works,
Fixed geometry turbocharger (FGT), as the name suggests, gives specific or fixed RPM where it gives the highest efficiency.
Fixed geometry turbocharger can be designed for two cases,
The advantages of the turbocharger are as follows,
The disadvantages of the turbocharger are as follows,
Now we know about turbochargers and superchargers. There are some differences between these two you may have seen it already by yourself after reading the post.
Still, let’s check out some differences between these two chargers.
|1.||Turbochargers consists of compressor as well as turbine.||Superchargers are only compressors.|
|2.||Turbochargers take power from the exhaust gases to rotate the turbine.||Superchargers takes power from the engine itself.|
|3.||They are connected to intake through exhaust pipe, turbine, compressor to inlet manifold.||They are connected to intake manifold through compressor.|
|4.||Mostly suitable for higher displacement engines.||Mostly suitable for smaller displacement engines.|
|5.||Turbochargers are costly.||Superchargers costs less comparatively.|
|6.||Takes time to give useful boost causing turbo lag.||Power delivery is immediate.|
|7.||More efficient in fuel and overall engine efficiency because it draws the power from the exhaust.||Less efficient, because it takes the power from engine itself.|
These are the differences between turbochargers and superchargers.
If you want to prefer one, the turbocharger is a good deal. Turbochargers can help in overall efficiency in multiple ways. But there are engines available that use superchargers as well as turbochargers known as twin-charged engines.
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