Wpływ recyrkulacji spalin na emisję związków szkodliwych spalin i parametry termodynamiczne silnika o zapłonie samoczynnym

An increase of the output parameters of modern DI Diesel engines correlates very closely with the in-cylinder parameters as pressure and temperature, which influence engine efficiency and emissions. The further development of this kind of engines is being restricted by NOx and PM limits, where the significant problem is, that the reduction of PM emission obtained by optimisation of thermodynamical parameters causes an increase of NOx emission and counter wise. Application of the controlled Exhaust Gas Recirculation (EGR) in low and middle load ranges could stand for an effective solution of this problem. The important question is, what an EGR-rate in this engine operating range should be matched. Another words, how the EGR-valve should be controlled and what kind of the controlling function should be evaluated and applied. For formulation of the optimal controlling function of the EGR-valve the investigations on the 4-cyl. 80 kW DI Diesel engine have been carried out. Research stand, measuring equipment and methodology of the investigations by changing of the EGR-mass flow have been presented in the paper. The obtained results, especially the sensitivity of engine parameters on changes in EGR-rate, could be treated as being representative for DI Diesel engines of LDV (Light Duty Vehicle) application range.