Search Results

This program examined the PAH emissions from two diesel engines representing state-of-the-art technology. One heavy-duty engine, a DDC Series 60, used in highway trucks, and one medium-duty engine, Navistar DTA-466, used in pick-up and delivery type vehicles. The medium-duty engine was tested for engine out emissions and with two different sized exhaust oxidation catalysts. Both of the catalysts were composed of a ceramic monolith coated with a palladium type catalyst. Both engines were tested according to the US EPA transient emissions test on a series of diesel fuels blended with varying aromatics and PAH contents to determine the impact of fuel quality on emissions. All diesel fuels had a low sulphur content (<0.05%) to minimize the formation of sulphate. The particulate matter was collected on teflon-coated filters, backed up with polyurethane foam filters to capture the vapour phase PAH.

The purpose of this paper is to investigate the piston temperature and temperature distribution with varying engine torques and speeds for a farm diesel engine. This analysis is based on the concept that the piston thermal system is considered to be one part of the whole engine energy system. That is, by thermodynamics cycle simulation, the heat transfer rate from gas to metals. was first calculated, and then the temperature distribution in the piston was obtained by an axi-symmetrical finite element heat conduction model. In order to verify the predicted values, input data for the cycle simulation were obtained, at the same time the piston temperature were measured. Some of the governing thermal boundary conditions of the piston were arrived at through a literature research. The calculated results indicate that heat transfer rate increases with engine speed. Also an increase in engine torque increases the heat release, hence also increases the time-averaged piston temperature.