Experimental Study On Improving Combustion And Emission Performance Of Compression Ignition Engine By Adding PODE

AbstractOwing to the serious hazy weather, PM2.5 is known by people gradually. Therefore, reduction the particle emission from motor vehicle is a hotspot of current research on engine. PODE is a new kind of alternative fuels which has good potential to reduce particle emission of compression ignition engine because of its property such as high cetane number, high oxygen content, high carbon-hydrogen bonds and no carbon-carbon bond. PODE is liquid state under atmosphere temperature and can be dissolved in diesel at any scales.In this thesis, the experimental study on the particle emission of diesel, PODE and diesel/PODE blended-fuel has been done on the basis of a compression ignition engine which produced by Yunnan Diesel Engine Enterprise. After that, CNG premixing system was added to the engine inlet tube for the study of the combustion mode on engine performance and emissions. A 2-stage dilution tunnel and SMPS were used in the study to measure particle size distribution of the test engine.The experimental result of PODE shows the particle number concentration of PODE is concentrated on the scale of less than 30 nm, and there is hardly particular larger than 30 nm, whereas the peak particular distribution of diesel engine is between 40-60 nm. On the other hand, NOX emission is higher than Diesel except under relatively low load.However, the experimental results of blended-fuel which is mixed by diesel and PODE with the volume rate of 9 to 1, 8 to 2 and 7 to 3 show that PODE is a good additive for diesel fuel. The reduction of particle emission of blended-fuel is obvious and the more PODE adding leads to the higher reduction. On the other hand, the burning performance of mixed-fuel is almost same with Diesel.The experimental results of the premixed CNG influence to combustion performance and emissions of PODE show that NOX emission declines while unburned HC emission rises. Particle emission of PODE also declines after premixed with CNG. The influence of premixed CNG to particular emission from diesel and PODE blended-fuel is strongly affected by the parameter of air-fuel equivalency.All the experimental results show that PODE has notable effect on particle emission reduction of compression ignition engine, and is a good vehicle diesel additive.