Abstract
The paper deals with theoretical potential of future design of ICE in terms of efficiency. The results were achieved by means of detailed thermodynamic simulation using system approach (0-D/1-D) – two engine models were applied. The first one is a turbocharged 3-cylinder 1.0L and the engine is supposed to be equipped with expensive technology to enable high flexibility (variable compression ratio, VVA, high efficiency turbocharger, etc). Different combustion concepts, namely standard SI, standard CI and ideal reaction controlled CI (RCCI) were evaluated. The engine setting was optimized to maximize BMEP (full load) and to minimize BSFC (part load). The concepts were compared from thermodynamic point of view. The second engine model is diesel 4-cylinder engine which was optimized without any constraints in several variant with the same maximum output parameters and different level of downsizing. Optimized parameters were similar to first engine but only CI combustion was applied. The geometrical parameters such as bore to stroke ratio was also optimized and it resulted into several variants of engines with fixed geometry optimized in wide range of speed and load. Fuel consumption of those engines was compared in vehicle driving cycle simulation.
KEYWORDS Internal combustion engine limits, low temperature combustion, early stage of concept, feasibility assessment, optimization of thermodynamic cycle