Characterization of Particulate Matter Emissions from a Current Technology Natural Gas Engine

This paper reports an evaluation of various combustion strategies aiming to reduce engine-out particulate matter (PM) emissions from a natural-gas fuelled heavy-duty engine. The work is based on a Westport HPDI fuelling system, which provides direct injection of both natural gas and liquid diesel into the combustion chamber of an otherwise unmodified diesel engine. The diesel acts as a pilot to ignite the natural gas, which normally burns in a non-premixed fashion, leading to significant PM formation. The concepts to reduce PM evaluated in this work are: 1) adjusting the relative phasing of the natural gas and diesel injections to allow more premixing of the natural gas prior to ignition; 2) reducing the pilot quantity to increase the ignition delay of the gas jet; and 3) reducing the level of EGR at select modes to reduce PM formation. These strategies are evaluated at steady state using single- and multi-cylinder research engines, supported by CFD analysis. The results demonstrate that allowing limited premixing of the gas jet prior to ignition can significantly reduce PM emissions. Excessive premixing can lead to high rates of pressure rise; EGR can be used to moderate the combustion under these conditions, without causing increased PM emissions. Reducing pilot quantity is another effective technique to reduce PM, primarily by allowing more air to mix with the gas jet before ignition. These various techniques can be combined to form a new operating strategy that significantly reduces engine-out PM and NOx emissions compared to the baseline strategy without significantly impacting fuel consumption.

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Characterization of the composition and toxicity of particulate matter emissions from advanced heavy-duty natural gas engines

10.33915/etd.542 ◽

2013 ◽

Author(s):

Arvind Thiruvengadam Padmavathy

Keyword(s):

Particulate Matter ◽

Natural Gas ◽

Heavy Duty ◽

Natural Gas Engines ◽

Particulate Matter Emissions

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Characterization of Particulate Matter Emissions From a 4-Stroke, Lean-Burn, Natural Gas Engine

ASME 2007 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2007-1648 ◽

2007 ◽

Author(s):

Kris Quillen ◽

Maren Bennett ◽

John Volckens ◽

Rudolf H. Stanglmaier

Keyword(s):

Particulate Matter ◽

Natural Gas ◽

Internal Combustion Engines ◽

Geometric Mean ◽

Operating Conditions ◽

Particulate Emissions ◽

Scanning Mobility Particle Sizer ◽

Health And Environmental Effects ◽

Gas Engine ◽

Natural Gas Engine

Regulatory agencies are becoming increasingly concerned with particulate emissions as the health and environmental effects are becoming better understood. While much research has been performed on diesel engines, little is known about particulate matter (PM) emissions from natural gas internal combustion engines. In this project, tests were conducted on a Waukesha VGF F18 natural gas engine running at full load. PM10 combustion emissions were collected on Teflon and quartz filters and a scanning mobility particle sizer (SMPS) was used to determine the particle size distribution. Tests were performed at 4, 5, 6, and 7% exhaust oxygen (O2) levels. Overall, it was found that a large number of small particles were emitted from this engine. The total mass based PM emissions were found to be 0.0148 gm/bkW-hr, which is slightly greater than the tier-4 nonroad diesel particulate emissions standard. Particle distributions revealed that the geometric mean diameter (GMD) of the natural gas particles was approximately 30 nm and did not change with air to fuel ratio. Particulate concentrations were found to decrease at leaner engine operating conditions. Results showed a strong correlation between the NOx and particle concentrations, while an inverse correlation between CO and particle concentrations was revealed.

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Effect of operating condition on particulate matter and nitrogen oxides emissions from a heavy-duty direct injection natural gas engine using cooled exhaust gas recirculation

International Journal of Engine Research ◽

10.1177/146808740400500602 ◽

2004 ◽

Vol 5 (6) ◽

pp. 499-511 ◽

Cited By ~ 7

Author(s):

G P McTaggart-Cowan ◽

S N Rogak ◽

P G Hill ◽

W K Bushe ◽

S R Munshi

Keyword(s):

Particulate Matter ◽

Natural Gas ◽

Nitrogen Oxides ◽

Direct Injection ◽

Exhaust Gas Recirculation ◽

Exhaust Gas ◽

Heavy Duty ◽

Gas Engine ◽

Natural Gas Engine ◽

Gas Recirculation

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Characterization of Particulate Matter Emissions From a Four-Stroke, Lean-Burn, Natural Gas Engine

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2906218 ◽

2008 ◽

Vol 130 (5) ◽

Cited By ~ 2

Author(s):

Kris Quillen ◽

Maren Bennett ◽

John Volckens ◽

Rudolf H. Stanglmaier

Keyword(s):

Particulate Matter ◽

Natural Gas ◽

Internal Combustion Engines ◽

Geometric Mean ◽

Operating Conditions ◽

Particulate Emissions ◽

Emission Standard ◽

Particulate Emission ◽

Gas Engine ◽

Natural Gas Engine

Regulatory agencies are becoming increasingly concerned with particulate emissions as the health and environmental effects are becoming better understood. While much research has been performed on diesel engines, little is known about particulate matter (PM) emissions from natural gas internal combustion engines. In this project, tests were conducted on a Waukesha VGF F18 natural gas engine running at full load. PM10 combustion emissions were collected on teflon and quartz filters and a scanning mobility particle sizer was used to determine the particle size distribution. Tests were performed at 4–7% exhaust oxygen (O2) levels. Overall, it was found that a large number of small particles were emitted from this engine. The total mass based PM emissions were found to be 0.0148gm∕bkWh, which is slightly greater than the Tier-4 nonroad diesel particulate emission standard. Particle distributions revealed that the geometric mean diameter of the natural gas particles was approximately 30nm and did not change with air to fuel ratio. Particulate concentrations were found to decrease at leaner engine operating conditions. Results showed a strong correlation between the NOx and particle concentrations, while an inverse correlation between CO and particle concentrations was revealed.

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