The impact of environmental conditions on the heat and emissions produced by large diesel engines in underground mines

Abstract

Diesel-powered equipment generates significant heat and emissions in an underground mine. Studies in literature demonstrate that changes in ambient temperature and relative humidity affect engine performance and its emissions, which may in turn affect worker exposure. This study builds and simulates models of six Tier 2 turbocharged diesel engines, including aftertreatment systems, with displacement between 12.8 and 18.9 liters, to determine what, if any, feedback mechanism exists between local changes in temperature, pressure, and relative humidity, and the output of heat, nitrogen oxides, and soot from the engines. This study analyzes the simulation results under conditions representative of an actual mine, where measurements of 29°C, 80% relative humidity, and 103 kPa ambient pressure represent baseline conditions. After engines had operated for two hours, these same measurements were 37°C, 60% relative humidity, and 103 kPa ambient pressure. In the period between baseline and peak-temperature conditions, heat output increases up to 1.9% across all models, soot increases up to 5.2%, and nitrogen oxides decrease up to 16%. Results from this study can be used in a production scheduling optimization model to improve thermal management of the mine and to minimize heat-related disruptions in operations.