The energy analysis and performance of heavy-duty diesel engine with n-butanol addition and different coolant temperature

Abstract

Energy flow assessment can grasp the distribution law of each energy balance term of engines and optimize the control parameters and related structures. In this study, the combustion and emission performance of a Euro-VI heavy-duty diesel engine were tested with different coolant temperature and addition of n-butanol. Research results shows that under idle and high-speed conditions, the position of maximum in-cylinder pressure (Pmax) moves backward with the increase of load. What’s more, and BSFC can only be effectively reduced when the coolant temperature is raised to 100 °C. About the exhaust energy flow, it can be concluded that the exhaust energy flow is not very sensitive to the coolant temperature, but the load and speed are. It is worth noting that coolant energy increased significantly as the ratio of butanol increased, and the proportion of the remaining loss is significantly reduced. Overall consideration, higher temperature of coolant has a positive effect on fuel consumption and Soot-NOx trade-off and coolant with a higher boiling point can improve engine performance and reduce energy loss. Moreover, the addition of a high proportion of n-butanol provides more room for energy recovery.