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Glavni predmet istraživanja u ovom radu je utjecaj „VIT“ sustava (eng. „Variable Injection Timing” – hrv. Sustav za promjenjivo vrijeme ubrizgavanja) i promjene temperature goriva na parametre rada glavnog motora. Istraživanje je provedeno na Kongsberg-ovom simulatoru (MC90-V), na način da su objašnjene kemijske i fizikalne karakteristike teškog goriva, koje ujedno služi i kao glavni radni medij, kao i princip rada samog sustava goriva. Zatim su provedena ispitivanja na raznim opterećenjima kroz raspon temperatura goriva s uključenim i isključenim VIT-om., SUMMARY Main subject of research in this final thesis is influence of the VIT system and change of the fuel temperature on operating parameters of the main engine. Research was carried out on Kongsberg's simulator (MC90-V), in such a way that the chemical and physical characteristics of heavy fuel oil are explained, which is used for operation of the main engine, as well as the working principle of the fuel oil system. Tests were then performed at various engine loads across different fuel temperatures with VIT system turned on and off.

Završni rad opisuje izvedbu sustava dobave plina prema glavnom motoru i pomoćnim motorima na brodu „Saga Dawn“ koji je namijenjen za prijevoz prirodnog ukapljenog plina (LNG). Kako izolacija tankova ne može biti savršena, u tankovima učestalo isparava teret. Teret se prevozi pri temperaturi od oko -161 °C i tlaku malo većem od atmosferskog. Isparavanjem tereta raste tlak u tanku, a tankovi tereta ne podnose visoke tlakove, stoga je izveden sustav koji omogućuje da se s isparenim teretom pogone motori i obavlja koristan rad. Direktno ispuštanje prirodnog plina u atmosferu je zabranjeno zbog velikog stakleničkog učinka. Specifičnosti koje karakteriziraju brod "Saga Dawn" su: četverotaktni glavni motor s mogućnošću rada na dvojno gorivo, nezavisni tankovi tipa "A" koji najveću primjenu imaju na LPG brodovima te mnoge druge. U radu su također pojašnjene funkcije pojedinih komponenti sustava, promjene stanja plina u pojedinim segmentima sustava te razvoj pogona LNG brodova tijekom povijesti., The final work describes the system's composition for feeding the main engine and auxiliary engines with gas on the ship "Saga Dawn", which is intended for the transport of liquefied natural gas. As the isolation of tanks can't be perfect, cargo in tanks boils. The temperature at which cargo is transported is about -161 °C and the pressure is a little bit higher than the atmospheric. The pressure increases due to the boiling of cargo in tanks. Cargo tanks on LNG carriers don't withstand high pressures. The system for feeding the engines with gas allows transforming boiling of gas into useful work. Direct release of liquefied natural gas is forbidden because of the high greenhouse effect. The specifics that characterize the ship "Saga Dawn" are a main dual fuel four-stroke engine, the independent tanks type "A", which are mostly used on LPG carriers, etc. The final work also describes the functions of individual components of the system, changes in gas state in different parts of the system, and the evolution of propulsion on LNG carriers.

U radu je opisano turbo-puhalo (TP), princip rada TP te utjecajem na rad dvotaktnog sporookretnog dizelskog brodskog motora. Opisana je fizička konstrukcija samog turbo-puhala te način na koji njegov rad doprinosi radu glavnog motora. Također je pojašnjena pojava pumpanja turbo-puhala. Objašnjen je indikatorski dijagram kao vrlo važan segment današnje dijagnostike kvarova te praćenja rada brodskog motora, In this paper the turbo blower is described as well as working principle and its effects to the two-stoke slow-speed marine diesel engine. Physical construction of a turbo blower is described and the effect of it`s performance on the performance of the main engine, also the phenomenon of the turbo-blower surge is described. Indicator diagram is presented as well because of it`s importance in today`s malfunction diagnostics and monitoring of the marine engine.