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| 21. |
Investigations of NOxReduction in the Exhaust of Diesel Engines by Selective Catalytic Reduction with Urea |
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Combustion Science and Technology,
Volume 153,
Issue 1,
2000,
Page 313-324
WERNER MÜLLER,
DIRK HEILIG,
SABINE MEYER,
GUIDO PORTEN,
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摘要:
Reduction of nitric oxides in the exhaust of Diesel-engines by urea-SCR is a well known technique for stationary operating engines. Conversion rates of up to 99 % are possible without slip of ammonia. However the application of urea-SCR for vehicles like trucks or passenger cars fitted with Diesel-engines requires additional information about the dynamic behaviour of different system components under various conditions of exhaust-gas temperature, space velocity and NOx-concentration level. This paper presents results of investigations sponsored by a research organization of the German industry, FVV (Forschungsvereinigung Verbrennungskraftmaschinen e.V.. Frankfurt). The results indicate that NOx-conversion is mainly dependant on exhaust-gas temperature, feed α (it means the mole number of ammonia farmed from urea addition related to the total mole number of nitric-oxides) and finally the space velocity. Conversion rates of up to 90% have been obtained at stationary engine conditions and more than 70% at dynamic engine operation starting with cold engine.
ISSN:0010-2202
DOI:10.1080/00102200008947267
出版商:Taylor & Francis Group
年代:2000
数据来源: Taylor
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| 22. |
Soot Catalytic Combustion in the Presence of NO |
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Combustion Science and Technology,
Volume 153,
Issue 1,
2000,
Page 325-337
P. CIAMBELLI,
V. PALMA,
P. RUSSO,
S. VACCARO,
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PDF (324KB)
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摘要:
The effect of NO on the activity of a Cu/V/K/CI based catalytic filter in the combustion of soot was investigated. Temperature Programmed Oxidation (TPO) of soot, collected on the filter at the exhaust of a gas-oil burner, was performed in a flow microreactor both in the absence and in the presence of NO. Similar tests were also carried out with uncatalytic filter. For the catalytic filter the presence of NO resulted in a substantial increase of the rate of carbon combustion, while for the uncatalytic filler the effect of NO was negligible. The influence of NO and O2/concentration in the gas fed to the reactor on the overall activity of the catalyst was also investigated.
ISSN:0010-2202
DOI:10.1080/00102200008947268
出版商:Taylor & Francis Group
年代:2000
数据来源: Taylor
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| 23. |
Prediction of In-Cylinder Turbulence for IC Engines |
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Combustion Science and Technology,
Volume 153,
Issue 1,
2000,
Page 339-368
I. CELIK,
I. YAVUZ,
A. SMIRNOV,
J. SMITH,
E. AMIN,
A. GEL,
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PDF (789KB)
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摘要:
This paper presents the preliminary results of some of a few of its kind efforts in large eddy simulation (LES) of engine flows to predict turbulent fluctuations, and the statistics of turbulence quantities inside IC engine cylinders. For this purpose, the well-known engine simulation code, KIVA, is used with special precautions to keep the numerical accuracy at a sufficiently high level, as well as using relatively fine grid resolution. The capabilities of this code are tested against benchmark cases, such as lid-driven cavity flow, and swirling and non-swirling free jet flows. It is then applied to a typical engine geometry under motored conditions. In particular, turbulence generated during the intake stroke, and the instabilities induced by a typical piston-bowl assembly are investigated. The computed velocity fluctuations, correlation coefficients and energy spectra of turbulent fluctuations are compared to experimental results. The predictions seem to extend well into the inertial range of turbulence and depict a good qualitative agreement with measurements. The results also shed light into the mechanisms by which turbulence may be generated by the piston-bowl assembly.
ISSN:0010-2202
DOI:10.1080/00102200008947269
出版商:Taylor & Francis Group
年代:2000
数据来源: Taylor
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