Experimental study on diesel engine EGR performance and Optimum EGR Rate Determination Method

In order to study deeply the Exhaust gas recirculation（EGR）performance of marine diesel engines，a venturi high-pressure exhaust gas recirculation device was established to overcome the exhaust gas reflow problem in a certain type turbocharged diesel engine. With the device, the EGR performance test is accomplished and an optimal EGR decision-making optimization method based on grey correlation coefficient modified is proposed. The results show that the venturi tube EGR can basically meet the injection requirements of high-pressure exhaust gas and makes good results to the diesel engine . Through the venturi tube EGR, the NOX emissions reduces significantly with the maximum drop of 30.6%. The explosive pressure in cylinder reduces with the EGR rate increases, and the cylinder pressure curve shows a single peak at low-speed conditions and double peaks at high-speed condition. However, the fuel consumption rate, NO, and smoke have been negatively affected. Due to small samples, the traditi...