ENERGY LOSSES IN FUEL INJECTOR

Sažetak Sve stroži zahtjevi glede smanjenih emisija zagađujućih tvari od motornih vozila u cestovnom prometu dovode do zahtjeva za stalnim unapređenjem tehničkih rješenja na motoru, te zahtjeva za korištenjem alternativnih goriva. Primjena alternativnih goriva kod dizelovih motora može biti raznovrsna što dovodi do zaključka o nužnosti kvalitetnog poznavanja značajki goriva i njihovog utjecaja na karakteristike ubrizgavanja. Analizom primjene različitih alternativnih goriva uočeno je da se osnovni pokazatelji procesa ubrizgavanja kao što su: tlak ubrizgavanja, trajanje procesa ubrizgavanja, količina ubrizganog goriva, itd. mijenjaju, što značajno utječe na proces izgaranja u dizelovom motoru. Zbog toga je nužno da se za optimalni proces izgaranja u dizelovom motoru podesi sustav za ubrizgavanje goriva. Posebno interesantno mjesto u sustavu za ubrizgavanje goriva je brizgaljka, gdje se vrši pretvorba potencijalne u kinetičku energiju, uz prisutnost značajnih energetskih gubitaka. Stoga je posebna pažnja posvećena obradi eksperimentalnih rezultata karakteristika ubrizgavanja i nabrojenih osnovnih pokazatelja procesa ubrizgavanja. Nakon provedene analize pristupilo se definiranju energetskih gubitaka u brizgaljci što će biti prezentirano u radu.Abstract New demands regarding reducing emissions of pollutants from motor vehicles in road transport lead to requests for continual improvement of technical solutions of the IC engine on one hand, as well as using of alternative fuels on the other. Application of alternative fuels in IC diesel engines could be different and it makes a conclusion based on necessity of well knowing fuel characteristics and its influences on injection characteristics. Based on analysis of different used alternative fuels, it has been noticed that basic parameters of fuel injection process, like injection pressure, injection duration, fuel injected amount, etc. were changed, influencing combustion process in the IC diesel engine. According to these facts, in order to make an optimal combustion process in the IC diesel engine, it is necessary to set up fuel injection system. A special part of fuel injection system is the injector, where transformation from potential to kinematic energy of fuel is conducted, with significant energy losses. Therefore special attention was dedicated to processing experimental results, first of all to shape the injection rate, as well as other mentioned injection characteristics. After analysis, a definition of energy losses in the injector was done and presented in the paper