Effect of hot exhaust gas recirculation on the performance and emissions of an advanced injection low pilot-ignited natural gas engine
The development of the advanced injection low pilot-ignited natural gas (ALPING) combustion concept that employs very small diesel pilots (1-5 per cent by energy) to compression ignite a premixed natural gas-air mixture to achieve very low NO<i><sub>x</sub></i> (0.2 g/kWh) and high efficiencies (about 41 per cent) has been described in a previous work. However, at part loads the ALPING combustion mode suffers from higher HC emissions (mostly unburned methane) and poor engine stability. To resolve this problem, tests were carried out employing various levels of hot EGR (0-26 per cent) at different loads on a single-cylinder research engine at a constant speed of 1700 r/min. Experimental results compared with baseline ALPING mode (0 per cent EGR) for quarter load operation are presented in the current paper. The results show that, at 60° BTDC injection timing, the application of hot EGR reduced HC emissions by up to 70 per cent without any significant NO<i><sub>x</sub></i> emissions penalty. The fuel conversion efficiencies were improved by 8 percentage points, while COV<sub>i.m.e.p.</sub> and CO emissions decreased 20 percentage points and 40 per cent, respectively. To identify the upper limits of hot EGR substitution, engine knock tests, which were conducted to identify audible knock limits, are also presented for a representative case (half load). The progress made by this project better positions ALPING combustion as a potentially viable approach to meet the regulatory and economic challenges of the future.(A)
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/issn/14680874
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Authors:
- QI, Y
- SRINIVASAN, K K
- KRISHNAN, S R
- YANG, H
- MIDKIFF, K C
- Publication Date: 2007
Language
- English
Media Info
- Pagination: 289-303
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Serial:
- International Journal of Engine Research
- Volume: 8
- Issue Number: 3
- Publisher: Sage Publications, Incorporated
- ISSN: 1468-0874
- EISSN: 20413149
Subject/Index Terms
- TRT Terms: Air quality management; Combustion; Emission control devices; Exhaust gases; Hydrocarbons; Ignition; Motors; Natural gas; Nitrogen oxides; Pollutants
- Uncontrolled Terms: Aftertreatment
- ITRD Terms: 3860: Combustion; 2442: Emission; 2433: Emission control; 3842: Exhaust aftertreatment; 7367: Hydrocarbon; 1327: Ignition; 1334: Motor; 7380: Nitrogen oxide; 2417: Renewable energy
- Subject Areas: Energy; Environment; Vehicles and Equipment; I15: Environment; I90: Vehicles;
Filing Info
- Accession Number: 01076234
- Record Type: Publication
- Source Agency: Transport Research Laboratory
- Files: ITRD
- Created Date: Sep 18 2007 10:21AM