The Effect of Cooled EGR on Emissions and Performance of a Turbocharged HCCI Engine
Author
Summary, in English
This paper discusses the effects of cooled EGR on a turbocharged multi-cylinder HCCI engine. A six-cylinder, 12-liter, Scania D12 truck engine is modified for HCCI operation. It is fitted with port fuel injection of ethanol and n-heptane and cylinder pressure sensors for closed-loop combustion control. The effects of EGR are studied in different operating regimes of the engine. During idle, low speed and no load, the focus is on the effects on combustion efficiency, emissions of unburned hydrocarbons and CO. At intermediate load, run without turbocharging to achieve a well-defined experiment, combustion efficiency and emissions from incomplete combustion are still of interest. However the effect on NOdx and the thermodynamic effect on thermal efficiency, from a different gas composition, are studied as well. At high load and boost pressure the main focus is NOdx emissions and the ability to run high mean effective pressure without exceeding the physical constraints of the engine. In this case the effects of EGR on boost and combustion duration and phasing are of primary interest. It is shown that CO, HC and NOdx emissions in most cases all improve with EGR compared to lean burn. Combustion efficiency, which is computed based on exhaust gas analysis, increases with EGR due to lower emissions of CO and HC.
Department/s
Publishing year
2003
Language
English
Pages
21-38
Publication/Series
SAE Special Publications
Volume
2003
Issue
1742
Full text
- Available as PDF - 252 kB
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Document type
Conference paper
Publisher
Society of Automotive Engineers
Topic
- Energy Engineering
Keywords
- EGR
- Combustion
- HCCI
- Engine
Conference name
SAE 2003 World Congress and Exhibition
Conference date
2003-03-03 - 2003-03-06
Conference place
Detroit, Michigan, United States
Status
Published
Project
- Competence Centre for Combustion Processes