Effect of EGR Combined with Intense Tumble Flow on a Well-Calibrated Commercial Turbocharged GDI Engine

摘要

A turbocharged GDI engine with variable intake tumble is used to study the effects of EGR combined with enhanced tumble on the engine's economy, power, and emissions characteristics. The effects of EGR with enhanced intake tumble flow, on the combustion phase, combustion duration, knock index and combustion cycle variation of the engine, were studied at two speeds of 1500 r/min and 2000 r/min from low to medium and to full load. The research shows that although the commercial engine has been well calibrated and optimized, the optimization of EGR and enhanced tumble flow together with the optimization of the ignition angle can improve the engine's economy and emission characteristics, while maintaining relatively fast burning speed and low combustion cycle variation. From medium to heavy load, the economy can be improved by 2.6 similar to 10 %, and the minimum fuel consumption can be reduced to 213 g/kW.h (eta(e) = 36.8 %). At the same time, the increase of the combustion cycle variation is controlled within 5 %, but as the load and the EGR ratio increase, the power loss cannot be compensated by the advance of the ignition angle. The 6 similar to 21 % EGR ratio brings 3.5 similar to 9 % power loss.