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The optimization study presented herein is aimed to minimize the fuel consumption and engine-out emissions using commercially available EN15940 compatible HVO (Hydrogenated Vegetable Oil) fuel. The investigations were carried out on FEV’s 3rd generation HECS (High Efficiency Combustion System) multi-cylinder engine (1.6L, 4 Cylinder, Euro 6). Using a global DOE approach, the effects of calibration parameters on efficiency and emissions were obtained and analyzed. This was followed by a global optimization procedure to obtain a dedicated calibration for HVO. The study was aiming for efficiency improvement and it was found that at lower loads, higher fractions of low pressure EGR in combination with lower fuel injection pressures were favorable. At higher loads, a combustion center advancement, increase of injection pressure and reduced pilot injection quantities were possible without exceeding the noise and NOx levels of the baseline Diesel.

Utilizing heat of exhaust gases for on-board alcohol reforming process (thermo-chemical recuperation - TCR) is a promising way of increasing the internal combustion engine (ICE) efficiency and emissions mitigation. Knowledge of the laminar burning velocity of alcohol reforming products is necessary for simulating performance of internal combustion engines with TCR and for in-depth studies of the combustion process. Laminar burning velocities of H2, CO, CO2 and CH4 mixtures that simulate methanol and ethanol steam reforming products for various water-alcohol ratios are investigated in this work. The influence of flame cellularity on burning velocity is studied as well. The burning velocity is measured experimentally using a spherical closed combustion vessel. Measurements are taken by a pressure measurement method during the pressure-rise period and prior to it by a high-speed Schlieren photography.