Partially Premixed Combustion with Methanol in a Heavy Duty Engine

Abstract: PPC is a new combustion concept that combines high efficiency with low emissions. This thesis is based on experiments conducted with a heavy duty PPC engine that was ran on neat methanol. A fuel that might be a candidate for future engine propulsion in large scale. By varying the inlet pressure, the corresponding inlet temperatures were found for premixed combustion, i.e. combustion in HCCI mode. Around the different operating points that were found in HCCI, the load range was investigated in PPC in the next experiment. By decreasing the temperature as the load was increased, the range of operation was extended many times compared to a constant inlet temperature. The results show a maximum load slightly above 9 bar IMEP, and the lowest load below 3 bar within the defined limitations of the load range. The highest indicated efficiency reached, was 51 percent for 1.5 bar inlet pressure. The emissions were also analyzed, and except for quite high levels of unburned hydrocarbons compared to emission standards, the obtained values were found to be promising.