The effect of multiple fuel injection on combustion profiles in slow-speed two-stroke marine diesel engines

This paper presents and explains the results obtained from a research on multiple injections in slow-speed two-stroke marine diesel engines. Research included a simulation model of engine operation processes. The validity of the model was verified by comparing the obtained values against measured values on three types of engines, Wartsila 7 RT Flex 50, MAN B&W MC 50 and ME 60. Pressure and temperature values in engine cylinder were obtained for every degree within a single full crankshaft revolution for two types of fuel injection: conventional and multiple fuel injections. Even though the experiments were carried out with five, six or seven injections respectively, research was restricted to three injections for practical purposes. Pressure and temperature parameters are processed in tables and in charts. First and second time derivatives of pressure and temperature were calculated, i.e. rate of change of pressure and temperature and acceleration of rate of change in pressure and temperature were calculated. Conclusions are drawn and solutions presented from the data mentioned above.