Experimental Investigation Of The After-treatment Devices Of Diesel Engines Fuelled With F-T Diesel,Conventional Diese And Their Blends

With high cetane number,low content of sulfur and aromatic hydrocarbon,Fischer-Tropsch(F-T)diesel is currently the most potential alternative fuel of excellence.They can be mono-fuel or blended diesel fuel with few diesel engine structure modification and parameters tuning.Diesel engines to meet the China IV emission standards,the present,after-treatment techniques is divided into selective catalystic reduction(SCR)and diesel oxidation catalystic(DOC)+ particle oxidation catalystic(POC)technique route.A research was did about influence of five different proportions of Fischer-Tropsch diesel blend fuels on diesel engine regulations,non-regulatory exhaust pollutants,concentration and size distribution for the exhaust particles with two applications on different after-treatment techniques high pressure common rail diesel engine whose emission can meet China IV emission standards.At the European steady state cycle(ESC)and European transient cycle(ETC)tests,after-treatment system resulted in a decrease of NOx and PM emissions,but can cause increase CO emissions.At the European load response Test(ELR)test,SCR system can reduce the emission of smoke.In most operating conditions,SCR after-treatment system causes an increase in exhaust particles concentration.Under different conditions,the size distribution of particle emissions before and after SCR system are a unimodal distribution,accumulation state of particles majority.At the ESC test,SCR system can significantly reduce the emission of methane,formaldehyde,acetaldehyde,acetone,benzene,1,3-butadiene,ethylenzene and xylene.At the ESC and ETC tests,DOC+POC after-treatment system for CO,HC and PM purification effect is very obvious,the conversion efficiency can often reach from 68% to 98%,but will cause NOx emissions than slightly increased.At the ELR test,DOC+POC system can significantly reduce the emission of smoke.In most operating conditions,DOC+POC after-treatment system causes a decrease in exhaust particles concentration.Under different conditions,the size distribution of particle emissions before and after DOC+POC system is essentially the same,but the peak particle emissions and the peak position of particulate matter will change with the operating conditions change.At the ESC test,DOC+POC system can significantly reduce the emission of formaldehyde,acetaldehyde,acetone,benzene,toluene,xylene,ethylbenzene and 1,3-butadiene.Although the SCR after-treatment system exhibits a significant reduction in NOx emissions,an increase in CO emissions is found in the meantime.SCR after-treatment system causes an increase in exhaust particles concentration,but DOC+POC after-treatment system causes a decrease in exhaust particles concentration.At the ESC test,SCR and DOC+POC after-treatment systems can significantly reduce the emissions of formaldehyde,acetaldehyde,acetone and other non-regulatory pollutants.After purification effect from after-treatment systems,SCR system formaldehyde and toluene purification better than DOC+POC system,acetaldehyde,acetone,ammonia,benzene,toluene,xylene and ethylbenzene purification effect inferior to DOC+POC systems.