| Abstract | Biodizel je vrsta goriva koja predstavlja potencijalnu zamjenu konvencionalnom dizelskom gorivu. U ovom radu, u svrhu ispitivanja utjecaja smjese biodizela i dizelskog goriva na karakteristike rada dizelskog motora, sintetizirani su metilni (FAME), propilni (FAPRE), butilni (FABE), pentilni (FAPE) i heksilni (FAHE) esteri masnih kiselina iz otpadnog ulja reakcijom transesterifikacije, nakon čega su pročišćavani i namiješavani u dvokomponentne smjese s konvencionalnim dizelskim gorivom. Dvokomponentnim smjesama biodizela i dizelskog goriva ispitivane su karakteristike rada motora na jednocilindarskom, četverotaktnom, zrakom hlađenom dizelskom motoru s unutarnjim izgaranjem. Pripremljene su smjese FAME, FAPRE, FABE, FAPE i FAHE s dizelskim gorivom u volumnim udjelima biodizela od 5, 10, 20 i 30 %. Mjerenja na motoru provedena su pri tri različite brzine vrtnje motora od 1200, 1600 i 2000 min-1 za tri različita opterećenja motora. Mjerene su i specifične emisije ispušnih plinova s obzirom na ostvarenu snagu motora i njihovi volumni udjeli te temperatura. Dvokomponentnim smjesama biodizela FAPRE i FAPE s dizelskim gorivom u volumnom udjelu biodizela od 10, 20 i 30 % ispitivano je raspršenje za tlak ubrizgavanja od 300, 500 i 700 bara za četiri različite duljine ubrizgavanja u trajanju od 0,6, 0,8, 1 i 3 ms. Smjese su ubrizgavane u stakleni okvir za atmosfersko ubrizgavanje, a domet i kut raspršenja mlaza određivani su sustavom za mjerenje s visokobrzinskom kamerom i laserom. Kako bi se podaci o karakteristikama rada dizelskog motora i raspršenja mogli dodatno potkrijepiti, svim smjesama biodizela i dizelskog goriva te čistim komponentama određene su kinematička viskoznost i gustoća pri četiri različite temperature od 15, 25, 40 i 60 °C. Na temelju provedenog ispitivanja, zaključeno je da je domet smjesa biodizela veći, a kut raspršenja manji u odnosu na čisto dizelsko gorivo zbog veće viskoznosti i gustoće biodizela. Potvrda tome su i podaci dobiveni mjerenjem viskoznosti i gustoće smjesa biodizela i dizelskog goriva. Mjerenjem karakteristika rada motora, dobiveno je da su emisije dušikovih oksida (NOx) i ukupnih ugljikovodika (THC) uglavnom manje, a emisije ugljikovog monoksida (CO) i dioksida (CO2) veće za smjese biodizela u odnosu na čisto dizelsko gorivo. |
| Abstract (english) | Biodiesel is a type of fuel that represents a potential replacement for conventional diesel fuel. In this work, for the purpose of examining the influence of a mixture of biodiesel and diesel on the performance characteristics of a diesel engine, methyl (FAME), propyl (FAPRE), butyl (FABE), pentyl (FAPE) and hexyl (FAHE) esters of fatty acids from waste cooking oil were synthesized via transesterification reaction, after which they were purified and mixed into two-component mixtures with conventional diesel fuel. Two-component mixtures of biodiesel and diesel were used to test the performance characteristics of a single-cylinder, four-stroke, air-cooled, internal combustion diesel engine. Mixtures of FAME, FAPRE, FABE, FAPE and FAHE with diesel were prepared in biodiesel volume fractions of 5, 10, 20 and 30 %. Measurements on the engine were performed at three different engine speeds of 1200, 1600 and 2000 min-1 for three different engine loads. Specific emissions of exhaust gases were also measured with regards to the achieved engine power and their volume ratios and temperature. Two-component mixtures of biodiesel FAPRE and FAPE with diesel in a volume fraction of biodiesel of 10, 20 and 30 % were tested for dispersion at injection pressures of 300, 500 and 700 bar with four different injection durations of 0,6, 0,8, 1 and 3 ms. The mixtures were injected into a glass frame for atmospheric injection, penetration and angle of the jet dispersion were determined by a measurement system with a high-speed camera and a laser. In order to further support the data on diesel engine operation characteristics and dispersion, kinematic viscosity and density were determined for all biodiesel and diesel mixtures and pure components at four different temperatures of 15, 25, 40 and 60 °C. Based on the conducted test, it was concluded that the range of biodiesel mixtures is greater and the fuel injection angleis lower compared to pure diesel due to the higher viscosity and density of biodiesel. This is confirmed by the data obtained by measuring the viscosity and density of biodiesel and pure diesel mixtures. By measuring the performance characteristics of the engine, it was found that the emissions of nitrogen oxides (NOx) and total hydrocarbons (THC) are mostly lower, and the emissions of carbon monoxide (CO) and dioxide (CO2) are higher for biodiesel mixtures compared to pure diesel. |
