Resumo:
With the growing energy demand, the rise of stricter environmental regulations, and the large-scale application of electric vehicles far from being a reality, new energy vectors for internal combustion engines have been considered. In this sense, biogas, biomethane, and syngas represent options that deserve some attention, despite not being widely used in Brazilian transportation. In addition to the use of new energy sources, innovative techniques – such as the dual fuel mode – can improve even further the potential of different fuels, such as HVO (hydrotreated vegetable oil), in order to optimize the engine operation in terms of efficiency and pollutants emissions. Therefore, the present thesis proposes experimental and numerical analyses in a single-cylinder diesel engine operating in dual fuel mode with fuels adaptable to the Brazilian energy matrix. The potential of theses fuels as partial replacements for diesel was verified, reducing NOx (up to 25.8%) and particulate matter (up to 86%) emissions, associated to a small decrease in thermal (up to 12.5%) and combustion (up to 4.2%) efficiencies. When diesel was replaced by HVO, improvements were observed in both emissions (NOx, CO, CO2, HC and particulate matter) and thermal efficiency. Finally, the combination of gaseous fuels with HVO led to the same trend observed for diesel, but with superior results for efficiency and emissions. In all the studied cases, the ANSYS Forte® CFD model offered additional understanding of experimental results, representing an option for extrapolation of results, optimization, and prediction of engine operation without the need of additional tests.
