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本文介绍在一台NREC3GS21B Gen Set机车上对L-CCRTTM颗粒物排放控制系统进行的验证试验。试验机车使用3套以柴油机为动力的发电机组(Gen 1、2和3),为机车的牵引电动机提供动力。机车由联合太平洋铁路的洛杉矶车队运送到位于德州圣安东尼奥市的SwRI机车技术中心(LTC),用于安装和测试3套Johnson Matthey公司的柴油机颗粒物过滤器(DPF)改装系统———L-CCRTTM。JML-CCRTTM系统在一个尾气过滤器的前方设有通流式柴油机氧化催化器。系统会加速氧化柴油机产生的NO,使之变为NO2,而NO2又不断地使催化的壁流式过滤器中烟尘氧化。这种连续的烟尘移除过程可避免柴油机的排气背压过分升高。机车的3台发动机每台均改配JM DPF壳体,取代其标准消声器。DPF壳体安装面与消声器大致相同,只是DPF比消声器高一些。作为机车改造项目的组成部分,对发动机上部的车顶进行了修改,使其能够容纳较高的DPF壳体。在机车的标定功率下运行了20 h,以对L-CCRTTM系统进行预处理,其后,机车按规定程序(美国联邦法规第40篇92-B部分)进行了测试。L-CCRTTM组件使HC排放减少99%,基本上杜绝了CO排放。与基准值相比,JM系统的调车循环加权燃油消耗量降低了2%,NOx排放则降低8.5%,其主要原因是排气背压的减小。PM排放减少99%,达到0.002 g/马力·h(1马力=0.735 kW),比机车Tier 4 PM限值低90%(该限值将于2015年对新造机车生效)。其后,该机车被运往加州进行为期9个月的运营,后于2012年4月初返回SwRI,以对Gen 3发动机进行修理,并进行1500 h排放测试。Gen 3发动机是因为过热而需要修理的。据认为,该故障是一起机械故障,6个气缸盖中的一个损坏。发动机修好之后,立即重新安装了DPF壳体,并进行了机车排放试验。1500 h排放试验表明,JML-CCRTTM使PM减少到0.010 g/马力·h,即降到了Tier 4 PM限值的76%以下。而且,HC和CO排放仍几乎为零。UPY2755于2012年5月在加州投入运营,以完成余下的1500 h耐久性运行。
This article describes the validation of the L-CCRTTM particulate emission control system on a NREC3GS21B Gen Set locomotive. The test locomotive used three diesel-powered generator sets (Gen 1,2 and 3) to power the traction motor of the locomotive. Locomotives were shipped from the Los Angeles Confederation Pacific Railroad to the SwRI Locomotive Technology Center (LTC) in San Antonio, Texas to install and test three Johnson Matthey Diesel Particulate Filter (DPF) retrofit systems, the L-CCRTTM. JML-CCRTTM system in front of an exhaust filter with a through-flow diesel oxidation catalyst. The system accelerates the NO generated by the oxidation of the diesel engine to NO2, which in turn continuously oxidizes the soot in the catalyzed wall-flow filter. This continuous soot removal process avoids excessive exhaust back pressure on the diesel engine. Each of the three locomotive engines is fitted with a JM DPF housing to replace its standard muffler. The DPF housing has approximately the same mounting surface as the muffler, except that the DPF is taller than the muffler. As part of a motorcycle retrofit project, the roof of the engine was modified to accommodate a higher DPF housing. Locomotives were operated for 20 h at the rated power of the locomotive to pretreat the L-CCRTTM system, after which the locomotive was tested in accordance with the prescribed procedures (Section 40, Part 92-B, CFR). The L-CCRTTM module reduces HC emissions by 99% and essentially eliminates CO emissions. Compared with the reference value, JM system shunt cycle-weighted fuel consumption decreased by 2%, NOx emissions decreased by 8.5%, mainly due to the reduction of exhaust back pressure. PM emissions have been reduced by 99% to 0.002 g / hp h (1 horsepower = 0.735 kW), 90% lower than the Tier 4 PM limit (this limit will be valid for new construction vehicles in 2015). The locomotive was then shipped to California for a nine-month operation and returned to SwRI in early April 2012 to repair the Gen 3 engine and conduct a 1500-h emission test. The Gen 3 engine needs repair due to overheating. It is believed that the failure is a mechanical failure, one of the six cylinder heads is damaged. After the engine was repaired, the DPF housing was immediately reinstalled and a motorcycle emission test was conducted. The 1500 h emission test showed that the JML-CCRTTM reduced the PM to 0.010 g / hh, ie below 76% of the Tier 4 PM limit. Moreover, HC and CO emissions are still almost zero. UPY2755 was put into operation in California in May 2012 to complete the remaining 1,500 hours of durability operation.