Supercharging is nowadaysa key technology for the development of internal combustion engines. Supercharging aims are the improvement of the mean effective pressure, the dynamic behavior, the specific fuel consumption as well as the compliance of emission limits.
Reducing the number of cylinders and the total engine displacement, downsizing along with the increased boost pressure leads to a higher mean effective pressure. Consequently, the efficiency is improved.At the same time peak pressure and heat flow rate are also increased andthe thermo-mechanical load of the engine components rises as well. Nonetheless, the improvement of the dynamic behavior (by adjustment devices or by switching turbochargers) often leads to an enlargement of negative gas exchange work and consequently to a loss of efficiency. Furthermore, the high pressure exhaust gas recirculation that is applied to reduce NOX emission also increases the gas exchange work. The advantage of the electrically driven compressor is the dynamic response and the efficiency of the turbocharger’s changing layout. However, the downsizing of a spark ignition engine stretches the engine to the knock limit and the turbocharger operates closer to the surge line. As far as thermo-mechanical processes are concerned the maintenance of exhaust gas temperature - leads due to the enrichment toa higher fuel consumption, since the rate of full load in the customers' driving operation rises. Nonetheless, the integrated exhaustgas manifold minimizes this disadvantage.
In the future the reduction of CO2 emission means the biggest challenge for the engine development.Especially since the annual limits of the exhaust gas emissions get even stricter.Moreover, new test methods (such as worldwide harmonized light duty vehicles test procedure, portable emissions measurement system, Real Driving Emissions) intensify the requirements.
The demand for a higher efficiency of commercial vehicle engines as well as low and medium speed diesel engines rises permanently. That matter of fact and compliance with NOX emission limits goes along with a very high pressure ratio and defines the supercharging concept for this reason. Gas engines have gained in importance in all fields of application.
Optimizing the supercharging of combustion engines requires a detailed knowledge about the behavior of the complete system. The operating performance can be predicted very well with simulation models. 3D computational fluid dynamics is an important tool for optimizing the intake area. Real time models are used to control the system. The complete system is tested on a highly dynamic engine test stand. Model-based control is here optimized by bypass structures.
At the 20th SUPERCHARGING CONFERENCE on 24th/25th September 2015 in Dresden the most current methods and results of development will be presented. Engine developing engineers and manufacturers of supercharging systems and other important components will contribute their part. The diversity of engines will reach from car engines up to low speed two-cycle ship engines. The conference will be held in German and English supported by simultaneous translation.
As a specialist conference the 20th SUPERCHARGING CONFERENCE represents a forum for all those who work on the development of supercharged combustion engines.