Turbochargers are essential tools in vehicles to increase an engine’s power output and torque, thereby increasing fuel efficiency and reducing emissions.
They have been used for many years with internal combustion engines, such as automobile engines, to provide increased airflow into the engine.
With their numerous uses, we can understand why there are different types of turbochargers. Here, we’ll discuss some of them for better understanding.
What is a Turbocharger?
A turbocharger is a forced induction system that helps increase the power and torque produced by a vehicle’s engine.
It does this by compressing the intake air entering the engine, increasing the pressure and temperature inside the cylinder.
The technology behind a turbocharger is quite simple, but it requires an intricate balance of components to work correctly. In fact, most modern engines use multiple turbochargers to help deliver better gas mileage and power output.
Like many things related to automotive engineering, Turbocharging dates back to the early 1900s. However, it wasn’t until the 1950s that engineers realized how much potential there was in turbocharging.
Different Types of Turbochargers
1. Single Turbos
The single turbocharger consists of a single turbine wheel near the exhaust manifold. This is opposed to a twin-turbo setup where two turbines are side-by-side.
You’ll usually find a single turbo on smaller engines like those used in scooters, motorcycles, and small cars.
In contrast to a twin-turbo, the single-turbo does not use a compressor stage. Instead, it relies solely on the energy generated by the combustion process to push air into the intake tract.
This makes the single turbo much simpler to design and manufacture than a twin-turbo system. As such, it is less expensive to produce and sell. However, because it lacks the benefit of a compressor stage, it is limited in terms of power output.
Another disadvantage of a single turbo is that you must mount it very close to the engine block. If it is too far away, then its effectiveness will decrease.
2. Twin Turbo
Twin is also among the different types of turbochargers. This type of turbocharger consists of two separate units mounted side-by-side. And people use it to increase the power output of an engine.
They work by compressing air into the combustion chamber. So, this increases the amount of fuel burnt per revolution of the crankshaft.
Moreover, the increased volume of air entering the cylinder causes more oxygen to enter the combustion process.
3. Variable Geometry Turbocharger
A variable geometry turbocharger (VGT) is a complex piece of equipment. With such a high level of complexity, there are many variables to consider when designing one. One of those variables is how you want to control the VGT.
There are several ways to control the VGT, and we’ll look at four of them here. The first way to control the VGT is to use a mechanical linkage.
In this case, the VGT uses a set of rotating arms that allow it to turn around the shaft. As the arms move, the angle of the blades changes, allowing the VGT to adapt to changing conditions.
The second method is to use an electronic actuator. Here, the VGT rotates around the shaft using a motorized device. The actuator controls the rotation, keeping the VGT’s angle constant.
The third option is to use a hydraulic mechanism. In this scenario, the pressurized fluid pushes against the rotor, causing it to turn.
Lastly, there is a fourth method that doesn’t involve moving parts. Instead, the VGT uses magnets to alter the airflow passing over the blades.
4. Twin Scroll Turbocharger
Among the different types of turbochargers is the twin-scroll turbocharger.
A twin-scroll turbocharger is similar to a single turbocharger. However, it differs substantially from the single turbocharger in terms of design. You’ll find the main difference in the chambers division.
While the single turbocharger divides the intake manifold into two separate sections, the twin-scroll turbocharger extends the intake manifold into two halves. Therefore, it allows a much larger air volume to be sucked into the combustion chamber.
The second significant difference is in the configuration of the volutes. In a twin-scroll turbocharger case, the volutes split into two pairs.
One pair of volutes is for cylinder one and cylinder 4, while the other pair is used for cylinders 2 and 3.
Each set of exhaust pulses drives a compressor wheel. Then, the compressor wheels compress the incoming air, thus increasing the pressure inside the combustion chamber.
5. Electrical Turbocharger
Electric Turbines are becoming increasingly popular due to their simplicity, reliability, and efficiency. However, there has always been one issue – turbo lag.
When you accelerate hard, the turbos struggle to produce enough boost to keep up with demand.
To resolve this, engineers developed mechanical turbochargers that use a spinning impeller to increase pressure inside the intake manifold. These turbines were very complex and required high maintenance costs.
In recent times, however, electrical turbochargers have become possible. Unlike traditional mechanical turbines, these devices do not require a spinning impeller to function. Instead, they use an electric motor to assist exhaust flow.
This eliminates turbo lag and allows engines to run much faster without sacrificing performance.
6. Dual Volute Turbocharger
The dual volute turbocharger is the last on our list of the different types of turbochargers.
Its turbine has its volute divided into two parts, allowing the exhaust gas to enter both sides of the turbine at the same time. This way, the flow is smoother, and there are no pulsations.
This concept is somewhat like the twin-scroll design, except that a single volute is used instead of two separate ones. In addition, the smaller volume allows for a larger diameter.
The advantage of a twin-scroll design is that it provides more extraordinary pressure rise and efficiency. However, the disadvantage is that it requires ample space and is, therefore, less efficient in terms of packaging.
In contrast, a dual volute turbochargER has the same advantages as a twin-scroll design while being much easier to package.
Conclusion
As you can see, many different types of turbocharger designs are available today. Each type has its pros and cons. So, understanding what each design offers is essential before choosing which one will work best for your application.
