The Research On EGR And Emulsifying Combustion Technology Of Marine Diesel

With the deterioration of the environment and the improvement of environmental awareness, the pollution of diesel engine has raised extensive attention all over the world,controlling the emission is a problem to be solved.As the exhaust gas recirculation(EGR) and water blending combustion technology had certain advantages and great potential for research in reducing the diesel emission, In this paper, the article had set a diesel engine simulation platform and through comparing with the test data the platform’s correction was validated, then carried on the simulation analysis of EGR and water blending combustion technology on a certain type marine diesel and had analyzed the influence of diesel index when the two technologies used. In the same time,based on the grey decision model, the article had evaluated the best EGR rate, water blending ratio and water fuel ratio.The results showed that with the increase of EGR rate, combustion flame retarding period increase, fuel consumption rate rose, NOx emissions and Soot emissions increased,EGR temperature rose would result in higher fuel consumption rate and the Soot emissions.After evaluation, the best EGR rate for this diesel is 0.05 .The diesel engine power reduction was 1%, a 1.1% increased in fuel consumption, Soot emissions increased by 25%, NOx emissions by 30.6%.When using water blending technology of emulsified oil, diesel engine NOx emission was reduced, and the fuel consumption rate and the Soot emissions rose, after combining with the EGR technology, they could further reduce NOx emissions, but led to the deterioration of fuel consumption and emissions of Soot. Using inlet humidifying technology,when the water fuel ratio was small, NOx emissions was reduced and a certain extent reduce in diesel engine fuel consumption rate and the Soot emission. However, when the water fuel was too large, although the NOx emission could be greatly reduced, but the fuel consumption rate and the Soot emission had increased significantly. After combining with EGR, when increasing the EGR rate properly, the diesel NOx reduced drastically, meanwhile the fuel consumption rate and Soot emission changed rarely. After evaluation, under the rated conditions, water blending technology of emulsified oil and EGR technology’s best matching value for water blending ratio 3%, EGR rate was 0.1, NOx emissions reduced by 56.6%;When inlet humidification combined with EGR technology the best matching value for water oil ratio was 0.8, and EGR rate was 0.1 .The NOx emissions dropped by 82.1%,Finally, through experiment research the results of propeller characteristics partial condition when EGR was applied on this diesel and got the law of these performance parameters’ change was obtained. After compared with the simulation results, the veracity of simulation model was verified.