Single-shot imaging of gas temperatures in low-temperature combustion based on laser-induced fluorescence of formaldehyde

2002 ◽  
Vol 29 (2) ◽  
pp. 2645-2651 ◽  
Author(s):  
Alfons Burkert ◽  
Wolfgang Triebel ◽  
Herbert Stafast ◽  
Jens König
Keyword(s):  
Low Temperature ◽  
Laser Induced Fluorescence ◽  
Single Shot ◽  
Low Temperature Combustion ◽  
Temperature Combustion

Speciation Analysis of Light Hydrocarbons and Hydrogen Production During Diesel Low Temperature Combustion

2011 ◽  
Author(s):  
Usman Asad ◽  
Arturo Mendoza ◽  
Kelvin Xie ◽  
Marko Jeftic ◽  
Meiping Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Hydrogen Production ◽  
Oxidation Catalyst ◽  
Individual Species ◽  
Hydrocarbon Emissions ◽  
Exhaust Aftertreatment ◽  
Boost Pressure ◽  
Single Shot ◽  
Low Temperature Combustion ◽  
Temperature Combustion

The simultaneous reduction in engine-out NOx and soot emissions with diesel low temperature combustion (LTC) is generally accompanied by high levels of hydrocarbon (THC) and carbon monoxide (CO) emissions in the exhaust. To achieve clean diesel combustion in terms of low regulated emissions (NOx, soot, THC, and CO), the exhaust combustibles must be dealt with the exhaust aftertreatment (typically a diesel oxidation catalyst). In this work, engine tests were performed to realize LTC on a single-cylinder common-rail diesel engine up to 12 bar IMEP. A single-shot fuel injection strategy was employed to push the diesel cycles into LTC with exhaust gas recirculation (EGR). The combustibles in the exhaust were generally found to increase with the LTC load and were observed to be a function of the overall equivalence ratio. A Fourier transform infrared (FTIR) spectroscopy analysis of light hydrocarbon emissions found methane to constitute a significant component of the hydrocarbon emissions under the tested LTC conditions. The relative fraction of individual species in the hydrocarbons also changed, indicating a richer combustion zone and a reduction in engine-out THC reactivity. The hydrogen production was found to correlate consistently with the CO emissions, largely independent of the boost pressure or engine load under the tested LTC conditions. This research intends to identify the major constituents of the THC emissions and highlight the possible impact on exhaust aftertreatment.

An Experimental Investigation of the Auto-Ignition Properties of Two C5 Esters: Methyl Butanoate and Butyl Methanoate

2007 ◽  
Author(s):  
Stephen M. Walton ◽  
Carlos Perez ◽  
Margaret S. Wooldridge
Keyword(s):  
Low Temperature ◽  
High Speed ◽  
Combustion Engine ◽  
Low Temperature Combustion ◽  
Moderate Pressure ◽  
Molecular Weights ◽  
Auto Ignition ◽  
Methyl Butanoate ◽  
Temperature Combustion ◽  
Time Histories

Ignition studies of two small esters were performed using a rapid compression facility (RCF). The esters (methyl butanoate and butyl methanoate) were chosen to have matching molecular weights, and C:H:O ratios, while varying the lengths of the constituent alkyl chains. The effect of functional group size on ignition delay time was investigated using pressure time-histories and high speed digital imaging. The mixtures studied covered a range of conditions relevant to oxygenated fuels and fuel additives, including bio-derived fuels. Low temperature and moderate pressure conditions were selected for study due to their relevance to advanced low temperature combustion strategies, and internal combustion engine conditions. The results are discussed in terms of the reaction pathways affecting the ignition properties.

Investigation of High Percentage Acetone-Butanol-Ethanol (ABE) Blended With Diesel in a Constant Volume Chamber

2014 ◽  
Author(s):  
Yilu Lin ◽  
Han Wu ◽  
Karthik Nithyanandan ◽  
Timothy H. Lee ◽  
Chia-fon F. Lee ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ambient Temperature ◽  
Constant Volume ◽  
Low Temperature Combustion ◽  
Transportation Fuel ◽  
Promising Alternative ◽  
Alternative Transportation ◽  
Constant Volume Chamber ◽  
Temperature Combustion ◽  
Acetone Butanol Ethanol

Bio-butanol, a promising alternative transportation fuel, has its industrial-scale production hindered significantly by high cost component purification process from acetone-butanol-ethanol (ABE) broth. The purpose of this study is to investigate the possibility of using ABE-Diesel blends with high ABE percentages as an alternative transportation fuel. An optical-accessible constant volume chamber capable of controlling ambient temperature, pressure and oxygen concentration was used to mimic the environmental conditions inside a real diesel engine cylinder. ABE fuel with typical volumetric ratios of 30% acetone, 60% butanol and 10% ethanol were blended with ultra-low sulfur diesel at 80% vol. and were tested in this study. The ambient temperature was set to be at 1100K and 900K, which represents normal combustion conditions and low temperature combustion conditions respectively. The ambient oxygen concentrations were set to be at 21%, 16% and 11%, representing different EGR ratios. The in-cylinder pressure was recorded by using a pressure transducer and the time-resolved Mie-scattering image and natural flame luminosity was captured using a high-speed camera coupled with a copper vapor laser. The results show that the liquid penetration is reduced by the high percentage of ABE in the blends. At the same time, the soot formation is reduced significantly by increasing oxygen content in the ABE fuel. Even more interesting, a soot-free combustion was achieved by combining the low temperature combustion with the higher percentage ABE case. In terms of soot emission, high ABE ratio blends are a very promising alternative fuel to be directly used in diesel engines especially under low-temperature combustion conditions.

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