Exhaust gas recirculation performance evaluation of marine diesel engine and its application

In view of EGR performance evaluation of turbocharged diesel engine, especially the optimal EGR rate under 'small sample', an optimization evaluation and decision-making method is proposed. First, the major test parameters including in-cylinder burst pressure, fuel consumption rate, NOx, CO and smoke are selected based onTBD234V12 type turbocharged diesel engine with a high-pressure exhaust gas recirculation system to establish the optimal correlation analysis model for the preliminary evaluation of different EGR schemes. Second, according to different speed conditions of diesel engine, a comprehensive evaluation model is established using optimized objective evaluation method. Finally, a simulation optimization platform for comprehensive performance evaluation and optimal decision-making of EGR is designed and established using MATLAB GUIDE. The results show that When diesel engine is in low-speed conditions, low EGR rate corresponds to a higher comprehensive assessment value, so a smaller EGR rate should be adopted. When diesel engine is in high-speed conditions, the comprehensive assessment value corresponding to the lower EGR rate is lower, and the higher EGR rate obtains a higher assessment value. However, the evaluation value of overly high EGR rate decreases. This result is basically consistent with the current control principle of EGR; The simulation optimization platform can quickly and easily solve the EGR performance evaluation and optimal decision-making of turbocharged diesel engine. © 2019, Jilin University Press. All right reserved.