Full
Outline
Under the engine testing conditions of world harmonized steady-state cycle(WHSC) and world harmonized transient cycle(WHTC), different ammonia nitrogen ratio(ANR) and exhaust temperature of the preceding stage and posterior stage were designed based on the selective catalytic reduction(SCR) reaction mechanism. The performance of the closed coupled SCR(cc-SCR) with different substrates at different ANR and exhaust temperatures was studied. The experiment result indicates that the addition of cc-SCR at the back of the supercharger can significantly improve the NOx conversion efficiency of the after-treatment system. The ANR of the preceding stage injection should not exceed 0.8 when selecting cc-SCR. The advantage of the vanadium-based cc-SCR over copper-based cc-SCR is lower N2O production. At low temperature, the NOx conversion efficiency of the copper-based cc-SCR is superior to that of the vanadium-based cc-SCR. And at 300—450℃, the NOx conversion efficiency of the two substrates catalysts is similar. At the steady-state operating point and exhaust temperature of 180℃, the overall NOx conversion efficiency of the vanadium-based & copper-based catalyst program decreases as the ANR increases, while the overall NOx conversion efficiency of the copper-based & copper-based catalyst program increases as the ANR increases. At high temperatures, the two scenarios convert NOx equally. Under the hot cycle of WHTC, the overall NOx conversion efficiency of the copper-based & copper-based catalyst program increases as the ANR increases.
5
1
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
