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Advantages of Exhaust Gas Turbocharging

Compared with a naturally aspirated engine of identical power output, the fuel consumption of a turbo engine is lower, as some of the normally wasted exhaust energy contributes to the engine's efficiency. Due to the lower volumetric displacement of the turbo engine, frictional and thermal losses are less.

The power-to-weight ratio, i.e. kilowatt (power output)/kilograms (engine weight), of the exhaust gas turbocharged engine is much better than that of the naturally aspirated engine.

The turbo engine's installation space requirement is smaller than that of a naturally aspirated engine with the same power output. A turbocharged engine's torque characteristic can be improved. Due to the so-called "maxidyne characteristic" (a very high torque increase at low engine speeds), close to full power output is maintained well below rated engine speed. Therefore, climbing a hill requires fewer gear changes and speed loss is lower.

The high-altitude performance of a turbocharged engine is significantly better. Because of the lower air pressure at high altitudes, the power loss of a naturally aspirated engine is considerable. In contrast, the performance of the turbine improves at altitude as a result of the greater pressure difference between the virtually constant pressure upstream of the turbine and the lower ambient pressure at outlet. The lower air density at the compressor inlet is largely equalized. Hence, the engine has barely any power loss.

Because of reduced overall size, the sound-radiating outer surface of a turbo engine is smaller, it is therefore less noisy than a naturally aspirated engine with identical output. The turbocharger itself acts as an additional silencer.

What is a Turbocharger ?

Why do we use one ?

An exhaust gas driven turbine, connected to, and driving a radial compressor, to supercharge the engine.

exhaust gas energy drives a (radial) turbine wheel

the flow of gas to the turbine wheel is controlled by the volute passage of the turbine housing

the turbine is mechanically connected to a radial compressor the impeller draws air from the atmosphere, and adds kinetic energy to it

this kinetic energy is converted to pressure in the compressor volute and diffuser sections

the shaft connecting the turbine and compressor wheels runs in bearings held in a central housing, which is supplied with oil for lubrication and cooling.

Adding extra air means extra fuel can be injected into the engine, and thus achieve better combustion.

increased engine power output (in the region of 50% increase)

improved fuel consumption (improved pressure balance across the engine)

improved emissions

altitude compensation

Generally summarize

The turbocharger makes use of exhaust air of an engine to drive a turbine. The running turbine drives a air compressing impeller running at high speed, the compressed fresh air is aspirated into the cylinders of the engine for increasing the air-fuel ratio. Improving efficiency, the fuel oil will burn enough, the fuel consumption will be decreased and the engine’s power will be increased. At the same time, with the improvement of the fuel condition, the elements, such as CO, HC, NOx and PM in the waste gas are decreased.

In high altitude areas, because lack lower air pressure, the power of an engine is reduced. But the engine with a turbocharger would compensate the decreased power because of insufficient air. The altitude is not more than 2500 meters)