Effect of Exhaust Gas Recirculation and Spark Timing on Combustion and Emission Performance of an Oxygen-Enriched Gasoline Engine

Jufang Zhang; Xiumin Yu; Zezhou Guo; Decheng Li; Tianqi Wang; Tianyang Gong; Tian You

doi:10.1021/acsomega.2c05034

Effect of Exhaust Gas Recirculation and Spark Timing on Combustion and Emission Performance of an Oxygen-Enriched Gasoline Engine

ACS Omega. 2022 Nov 11;7(46):42208-42220. doi: 10.1021/acsomega.2c05034. eCollection 2022 Nov 22.

Authors

Jufang Zhang^{1

2}, Xiumin Yu^{1

2}, Zezhou Guo^{1

2}, Decheng Li^{1

2}, Tianqi Wang^{1

2}, Tianyang Gong^{1

2}, Tian You³

Affiliations

¹ State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun, Jilin130022, China.
² College of Automotive Engineering, Jilin University, Changchun130022, China.
³ Changchun Vocational Institute of Technology, Changchun130022, China.

Abstract

Oxygen-enriched combustion (OEC) technology in SI engines can greatly improve the degree of constant volume combustion, increase the torque output, and reduce HC and CO emissions but lead to a sharp increase in NO _x emissions. Simultaneously, the high temperature from OEC would lead to high nucleation particle emissions. Under the OEC mode, except the oxygen content, spark timing and engine load are important influencing factors on emissions. Exhaust gas recirculation (EGR) technology has been proven to reduce NO _x emissions effectively. This research investigates the effects of EGR on combustion and emission performance under an oxygen-enriched ratio (OER) of 25% with five EGR ratios (0-20%) for the initial throttle opening of 14% (at an EGR ratio of 0%) with an engine speed of 1500 rpm. The study shows that when the OER is 25%, the output torque increases with the increase of the EGR ratio. At the proper spark timing, the EGR ratio over 15% can obtain lower NO _x emissions and particle emissions than the baseline (OER of 21%). Although HC emissions increase with the EGR ratio, they are still lower than the baseline. Overall, the OER of 25% coupled with the EGR ratios of 15-20% is the predominant combustion mode to improve power and emission performance in SI engines.