12-06-2014, 10:43 AM
A SEMINAR ON TURBOCHARGER IN LOCOMOTIVES
TURBOCHARGER.pptx (Size: 1.09 MB / Downloads: 66)
INTRODUCTION
It is derived from Greek turbin’, turbō which means mixing/spinning.
It is invented by Swiss engineer Alfred Buchi in 1905 and the turbocharger in locomotives began in 1920s.
Nowadays aircrafts like P-47 thunderbolt,P-38 lightening and automobile cars are using this for greater efficiency.
WHAT IS TURBOCHARGER
It is a device to increase the volumetric efficiency above that value which can be obtained by natural aspiration.
A turbocharger is a forced induction device which increases the air density. Basically it is an air compressor provides denser charge to the engine.
WORKING PRINCIPLE
A turbocharger consists of a turbine and a compressor on a shared shaft.
The turbine section of a turbocharger is a heat engine in itself. It converts the heat energy from the exhaust to power, which then drives the compressor, compressing ambient air and delivering it to the air intake manifold of the engine at higher pressure, resulting in a greater mass of air entering each cylinder.
In some instances, compressed air is routed through an intercooler before introduction to the intake manifold.
TURBOCHARGING VERSUS
SUPERCHARGING
Turbocharging & supercharging are only differed by their input method where turbocharger powered by exhaust gases but supercharger driven by engine mechanically.
A combination of an exhaust-driven turbocharger and an engine-driven supercharger can mitigate the weaknesses of the other. This technique is called twincharging.
ADVANTAGES
Provides better air-fuel mixture to the locomotive engine.
As the air is compressed, the fresh charge always have a high temperature. So, less engine load is applied to compress the charge in combustion chamber.
No extra driving power requirement as it’s turbine is driven by the exhaust gases of the locomotive engines.