外部燃料重整掺氢对天然气发动机性能的影响

利用外部燃料重整系统对天然气燃料进行了重整反应,燃料重整率为12％,将反应后的重整气体通入进气管内与新鲜空气混合,再通入气缸内燃烧,以此来比较外部燃料重整掺氢燃烧对天然气发动机性能的影响.试验结果显示:结合外部燃料重整掺氢燃烧,发动机的循环变动明显改善,燃烧持续期缩短,相同工况下的燃料消耗率变化很小;THC排放量在各工...     

Study on Oxidation Activity of CuCeZrO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> Doped with K for Diesel Engine Particles in NO/O<Subscript>2</Subscript>

CuCeZrO_x and KCuCeZrO_x catalysts were synthesized and coated on the blank diesel particulate filter (DPF) substrate and a particulate matter (PM) loading apparatus was used for soot loading. The catalytic performances of soot oxidation were evaluated by temperature programmed combustion (TPC) test and characterization tests were conducted to investigate the physicochemical properties of the catalysts. The reaction mechanism in the oxidation process was analyzed with diffuse reflectance infrared Fourier transform spectroscopy. The results demonstrated that CuCeZrO_x catalyst exhibited high activities of soot oxidation at low temperature and the best results have been attained with Cu_0.9Ce_0.05Zr_0.05O_x over which the maximum soot oxidation rate decreased to 410 °C. Characterization tests have shown that catalysts containing 90% Cu have uniformly distributed grains and small particle sizes, which provide excellent oxidation activity by providing more active sites and forming a good bond between the catalyst and the soot. The low-temperature oxidation activity of soot could be further optimized due to the excellent elevated NO’s conversion rate by partially substituting Cu with K. The maximum particle oxidation rate can be easily realized at such a low temperature as 347°C.     

电加热金属载体催化剂对汽油机冷起动阶段排放性能的影响

采用电加热金属载体催化剂(EHC),研究了加热电压、加热时间以及贵金属涂敷量对汽油发动机冷起动排放性能的影响.试验结果表明:EHC载体热容小,升温快,THC、CO和NOx的转化效率比陶瓷载体高;加热电压越大,EHC加热功率越大,直接影响THC、CO和NOx的转化效率;EHC加热一定时长后,继续增加加热时间,不一定能达到减排效果;通过EHC的应用,能够减少三元催化器50％的贵金属用量.