A New Paraffinic Fuel Impact on Emissions and Combustion Characteristics of a Diesel Engine 2002-01-2218

Having low aromatic compounds, high cetane rating, higher heat of combustion and almost zero sulphur content, a new paraffinic fuel (NPF), developed by Oroboros AB Sweden, was believed to receive attention as a new alternative fuel. Therefore, further investigation and combustion analyses were conducted in a research single-cylinder diesel engine, where detailed thermodynamic analyses were performed by Burst to File high frequency signal sampling code and by the Dragon software, revealing the real thermochemistry history.

The aim of this investigation was an effort to reduce the pollution levels in Santiago de Chile by introducing this new paraffinic fuel (NPF). Experimental results have shown that the NPF fuel has a significant impact not only on the emission levels, but also on other energetic parameters of the engine such as ignition delay, cylinder peak pressure, heat release gradient, indicated efficiency etc. It is observed that NPF fuels have shorter ignition delay and longer combustion duration when compared with those obtained when the engine runs on standard Chilean fuel (SCF) at the same operating point.

As shown by the evaluated rate of heat release in the premixed zone, the fraction of premixed combustion is larger for CSF fuel than for NPF fuel. This is an indication for smooth engine running, lower combustion rate, and lower NO_x formation. As a complement to this, in-cylinder processes with lower peak pressure and earlier location are more favourable when the engine runs on NPF. It may be stated that NPF, which is a selected optimised C chain-length variation mixture [2], [3], [4], can be used in unmodified compression ignition engines with significant reduction of regulated emission (NO_x, HC, CO, CO₂), soot, fuel consumption and smoother thermodynamic characteristics. Therefore, the NPF might be considered as a strong competitive alternative fuel [5], [6].