Feasibility Study of Cylinder Deactivation (CDA) Technology for an Off-Highway Tractor Engine

Cylinder Deactivation Technology is explored as an effective mechanism for enhancing the fuel economy and reducing emissions in internal combustion engines. The current exercise focuses upon the feasibility of Cylinder Deactivation Technology on a 3-cylinder, 3.3-liter naturally aspirated water-cooled diesel engine from the off-highway tractor application. A meticulous 1D thermodynamic simulation with individual cylinders deactivated one by one, proved that deactivating the second cylinder yielded the most favorable fuel economy, emissions and engine balancing, particularly at the loads lower than 55% and engine speeds higher than 1600 rpm. Upon deactivating the cylinders at Top Dead Centre (TDC) and Bottom Dead Centre (BDC), it was concluded that the most effective deactivation point occurred at TDC, where the minimum air mass is trapped inside the cylinder. This resulted in a reduction of pumping losses by maximum 29% and an increase in brake thermal efficiency by maximum 4%, as compared to the baseline engine. The in-cylinder trapped A/F ratio becomes richer by 32% when cylinder deactivated. As a consequence, the C1-8 mode NRSC cycle average HC & CO reduces by 22% & 28%, respectively. CO2, NOx and PM remains same, variation less than 2% with respect to the baseline. The maximum increase in exhaust temperature when mid cylinder deactivated was observed 109°C. The reduction in space velocity is 35%, which would be eventually beneficial for the aftertreatment catalyst activation. These observations were duly validated through the engine dynamometer testing and tractor trials in haulage application.