直喷式柴油机燃用F-T柴油时的性能与排放

煤通过Fischer-Tropsch（F-T）合成可以获得十六烷值高、硫和芳香烃含量极低的F-T柴油.在一台未作改动的单缸直喷式柴油机上对燃用F-T柴油时发动机的性能和排放进行了研究.结果表明,在相同工况下与燃用常规柴油相比,燃用F-T柴油时的滞燃期较短,预混燃烧放热峰值较低,扩散燃烧放热峰值较高,最高燃烧压力略低,最大压力升高率显著下降,燃油消耗率和热效率都得到了改善.燃用F-T柴油可同时降低CO、HC、NOx和碳烟排放,其中NOx和碳烟排放分别平均降低了16.7%和40.3%.研究表明F-T柴油是柴油机优秀的清洁代用燃料.

Performance and Emissions of a Direct Injection Diesel Engine Operating on Fischer-Tropsch (F-T) Diesel Fuel

Through Fischer-Tropsch(F-T) processes,coal can be converted to F-T diesel fuel with high cetane number,very low sulfur and aromatic contents.In this paper,the performance and emissions of an unmodified single-cylinder direct injection diesel engine operating on F-T diesel fuel were studied and the comparison to those of conventional diesel fuel was made.The results showed that F-T diesel fuel exhibited shorter ignition delay,lower peak value of premixed burning rate,and higher peak value of diffusive burning rate than those of conventional diesel fuel at the same speed-load point.In addition,F-T diesel fuel has a slightly low peak combustion pressure and a much low rate of pressure rise.Low brake specific fuel consumption and high effective thermal efficiency were presented for F-T diesel fuel operation.CO,HC,NO_x and smoke emissions of F-T diesel fuel reduced at all tested speed-load points compared to the conventional diesel fuel.Averagely,NO_x and smoke emissions reduced by 16.7% and 40.3% respectively with F-T diesel fuel.The study demonstrates that F-T diesel fuel is an excellent clean alternative fuel for diesel engines.