Experimental Study on the Effects of Intake Parameters on Diesel LTC Combustion and Emission

The diesel low temperature combustion (LTC) can keep high efficiency and produce low emission. Which has been widely studied at home and abroad in recent years. The combustion control parameters, such as injection pressure, injection timing, intake oxygen concentration, intake pressure, intake temperature and so on, have an important influence on the combustion and emission of diesel LTC. Therefore, to realize different combustion modes and combustion mode switch of diesel engine, it is necessary to accurately control the injection parameters and intake parameters of diesel engine. In this work, experimental study has been carried out to analyze the effect of intake oxygen concentration, intake pressure and intake temperature in combustion and emission characteristics of diesel LTC, such as in-cylinder pressure, temperature, heat release rate, NOx and soot emission. The experimental results reveal that, with the decrease of intake oxygen concentration, the ignition delay is prolonged while the in-cylinder pressure and NOx emission decrease gradually whilst the heat release rate and soot emission increase at the beginning, followed by a decline. By contract, the result show that with the increase of the intake pressure, the ignition delay is shortened, whereas the in-cylinder pressure and heat release rate increase while the NOx and soot emission both decrease. In addition, the study presents that the ignition delay is shortened while the in-cylinder pressure and heat release rate grow and the NOx and soot emission go up with the increase of intake temperature. Based on the investigation, this paper provides a theoretical basis for combustion optimization and control of diesel LTC.