The topic of turbocharging diesel engines is considered one of the most interesting to study. The development and application of twin-turbo engines stands out in this area.
Internal combustion engines and diesel power units are driven by the energy released when the air / fuel mixture is burned. If the pumping of fuel can be carried out exclusively by a fuel pump, then there are several methods of air intake. Aspirated engines, characterized by the simplicity of the device, receive air from the environment under the influence of the natural vacuum that is formed in the carburetor. However, they have a significant drawback, expressed in low power, which is completely eliminated in turbocharged and bi-turbo engines.
About the turbocharger
The principle of forced air injection into the combustion chamber of a diesel engine was known at the end of the 19th century, but Alfred Büchi received a patent for a turbocharger only in 1911. The invention of the turbocharger was one of the results of research on methods for increasing the power of a diesel engine, of which the principle of forced injection of the combustion chamber with pre-compressed air was considered the most promising. The excess air in the combustion chamber allowed up to 99% of the fuel mixture to be burned, which provided the turbocharged engine with increased power without tangible compromises in efficiency.
How a supercharger works
The principle of operation of a turbocharger is based on the use of energy from exhaust gases. High pressure gas from the exhaust manifold passes through the turbine, spinning it up. The turbine shaft is directly connected to the rotor of the centrifugal compressor, which prepares the air for the intake manifold. The turbocharger performance is directly related to the current engine power.
Biturbo engine
In the modern automotive industry, more and more attention is paid to the dynamic characteristics of vehicles. Sometimes even the advantages of turbocharged engines over atmospheric ones are not so pronounced. The fact is that the need for the presence of oxygen in the combustion chamber does not have a linear dependence on the increase in torque. Simply put, there is a certain power threshold beyond which the turbocharger's performance is not sufficient to fully exploit the potential of a diesel engine.
This disadvantage was completely eliminated with the advent of the engine with a double turbocharger. When the engine exceeds the compressor capacity threshold, a second turbocharger is activated. It has a higher performance, which, in turn, is too high for the power unit to operate at low revs. The design of the biturbo engine allows for an increase in power by burning more fuel instead of expanding the volume of the working area of the cylinder.
