Exploration of Semi-Volatile Particulate Matter Emissions from Low Temperature Combustion in a Light-Duty Diesel Engine
Diesel low temperature combustion (LTC) is an operational strategy that is effective at reducing soot and oxides of Nitrogen (NOx) emissions at low engine loads in-cylinder. A downside to LTC in diesel engines is increased hydrocarbon (HC) emissions. This study shows that semi-volatile species from...
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Published in | SAE International journal of engines Vol. 7; no. 2; pp. 852 - 859 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Warrendale
SAE International
2014
SAE International, a Pennsylvania Not-for Profit |
Subjects | |
Online Access | Get full text |
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Summary: | Diesel low temperature combustion (LTC) is an operational strategy that is effective at reducing soot and oxides of Nitrogen (NOx) emissions at low engine loads in-cylinder. A downside to LTC in diesel engines is increased hydrocarbon (HC) emissions. This study shows that semi-volatile species from LTC form the bulk of particulate matter (PM) upon dilution in the atmosphere. The nature of gas-to-particle conversion from high HC operating modes like LTC has not been well characterized. In this work, we explore engine-out PM and HC emissions from LTC and conventional diffusion combustion (CC) operation for two different engine load and speed modes using a modern light-duty diesel engine. An experimental method to investigate PM volatility was implemented. Raw exhaust was diluted under two dilution conditions. A tandem differential mobility analyzer (TDMA) was used to identify differences in volatility between particle sizes. The study revealed that LTC PM mass and number concentration showed a greater dependence on dilution conditions than PM from CC. There was also evidence of differences in particle volatility as a function of particle size for PM from LTC, with PM from CC having more consistent volatility characteristics. The results of this study show that significant semi-volatile PM emissions are present in LTC exhaust compared to CC operation though they are highly dependent on dilution conditions. This indicates that gas-to-particle conversion processes require additional study to identify the clear impact of LTC implementation on real-world PM emissions. |
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Bibliography: | 2014-04-08 ANNUAL 211773 Detroit, Michigan, United States |
ISSN: | 1946-3936 1946-3944 1946-3944 |
DOI: | 10.4271/2014-01-1306 |