Suzuki, H., Koike, N., Ishii, H., and Odaka, M., "Exhaust Purification of Diesel Engines by Homogeneous Charge with Compression Ignition Part 1: Experimental Investigation of Combustion and Exhaust Emission Behavior Under Pre-Mixed Homogeneous Charge Compression Ignition Method," SAE Technical Paper 970313, 1997, https://doi.org/10.4271/970313.
A homogeneous Charge Compression Ignition Diesel Combustion (HCDC) system has been experimentally studied for it's effect on exhaust purification of diesel engines. In this system, most fuel is injected into the intake manifold to form homogeneous pre-mixture in the combustion chamber beforehand and the pre-mixture is ignited with a small amount of fuel directly injected into the cylinder by a conventional injection system. Because this system performs homogeneous lean-burn, it can realize low emission which cannot be realized by conventional diesel engines without impairing ignition controllability in the operations ranging from idle to full load.In particular, although the operating regions were strictly limited, extremely low Nox emission levels of as low as 10 to 40 ppm were realized with maintaining low smoke emissions, when the ratio of pre-mixed fuel was increased up to approx. 98%.Also, when EGR was used, an Nox concentration lower than 100 ppm in wide range of load as well as a smoke emission lower remarkably than that by ordinary diesel combustion could be realized.This report on HCDC system covers the experimental results and simple analysis on how combustion and exhaust emissions vary when the ratio of pre-mixed fuel to total fuel or antiknock factors of the fuel are varied, whether or not low air pollution can be realized in wider load ranges, and whether or not low air pollution is achieved by EGR.