The Effects of Coolant Temperature on the Performance and Emissions of a Single-Cylinder Divided-Chamber Diesel Engine

Comparative experiments were performed on an experimental divided-chamber diesel engine for three coolant conditions: baseline (water at 82°C), high coolant temperature (glycol at 120°C) and a differential cooling condition where the antechamber was kept cold (water at 20°C) and the main chamber was kept hot (glycol at 120°C). High-temperature cooling was found to provide a significant brake-specific-fuel-consumption advantage at low-speed and low-load conditions and at very retarded combustion-timing conditions. In general, high coolant temperature caused an increase in hydrocarbon (HC) emissions. Lowering the antechamber surface temperature at the low-speed conditions was found to cause an increase in gaseous emissions and a reduction in smoke and particulate emissions.