Study on an Electronically Controlled EGR System of YC4112Z_LQ Diesel Engine

For reducing NOx emissions of diesel engines, an electronically controlled EGR system was developed based on a supercharged, intercooled YC4112ZLQ diesel engine. The effects of different EGR rate on the performances and emissions of the engine were researched by engine tests, and the EGR rates of different engine modes were optimized according to the test results for meeting the EURO Ⅱ emission standard, then the control parameters under the optimum EGR rates were calibrated. An electronically controlled EGR system was designed based on the calibration results and used to control the EGR rates in different conditions. The dynamometer tests show that with the help of the EGR control system, the NOx emissions of the engine are reduced by 129% with the particulate emissions increased slightly and the engine total emissions under 13 modes meet the requirements of the EURO Ⅱ emission standard.