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Evaluation of SI engine exhaust gas emissions upstream and downstream of the catalytic converter
- Source :
-
Energy Conversion & Management . Nov2006, Vol. 47 Issue 18/19, p2811-2828. 18p. - Publication Year :
- 2006
-
Abstract
- Abstract: The conversion efficiency of a catalytic converter, mounted on a vehicle equipped with a 2.8l spark ignition engine, was evaluated under steady state operating conditions. The inlet and outlet chemical species concentration, temperature and air fuel ratio (A/F) were measured as a function of the brake mean effective pressure (BMEP) and engine speed (rpm). Oil temperature, coolant temperature, brake power and spark advance were also monitored. In parallel, a mathematical model for the catalytic converter has been developed. The main inputs of the model are the temperature, flow rate, chemical species mass flow and local A/F ratio as measured at the catalyst inlet section. The main conclusions are: (i) the exhaust gas and substrate wall temperatures at the catalyst outlet increase with BMEP and rpm; (ii) the HC conversion efficiency increases with the value of BMEP up to a maximum beyond which it decreases; (iii) the CO conversion efficiencies typically increase with BMEP; (iv) the NO x conversion efficiency remains nearly constant regardless of BMEP and rpm; (v) except for idle, the NO x conversion efficiency is typically the highest, followed in turn by the CO and HC conversion efficiencies; (vi) conversion efficiencies are lower for idle conditions, which can be a problem under traffic conditions where idle is a common situation; (vii) regardless of rpm and load, for the same flow rate the conversion efficiency is about the same; (viii) the model predictions slightly over estimate the exhaust gas temperature data at the catalyst outlet section with the observed differences decreasing with BMEP and engine speed; (ix) in general, the model predictions of the conversion efficiencies are satisfactory. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 01968904
- Volume :
- 47
- Issue :
- 18/19
- Database :
- Academic Search Index
- Journal :
- Energy Conversion & Management
- Publication Type :
- Academic Journal
- Accession number :
- 21663453
- Full Text :
- https://doi.org/10.1016/j.enconman.2005.05.026