The Effects of Depth on Diesel Engine Emissions in an Underground Mine

The effects of depth on diesel engine emissions were measured on an in-use, heavy-duty articulated loader vehicle operating in an underground mine. The engine emissions were measured using a portable gas analyzer bench at various depths from surface to 7000 ft below sea level. Generally, the carbon monoxide (CO) and diesel particulate matter (DPM) emissions decreased with depth due to the increase in the air density and overall air/fuel ratio. Oxides of nitrogen (NOx) emissions increased with depth, likely due to the pressure effect on in-cylinder NO formation.