Emissions from ethanol-blended fossil fuel flames

Journal Article · Sat Jan 15 00:00:00 EST 2011 · Experimental Thermal and Fluid Science

DOI:https://doi.org/10.1016/J.EXPTHERMFLUSCI.2010.08.010· OSTI ID:21390715

Akcayoglu, Azize ^[1]

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1. Mersin University, Faculty of Technical Education, Tarsus, Mersin (Turkey)

A fundamental study to investigate the emission characteristics of ethanol-blended fossil fuels is presented. Employing a heterogeneous experimental setup, emissions are measured from diffusion flames around spherical porous particles. Using an infusion pump, ethanol-fossil fuel blend is transpired into a porous sphere kept in an upward flowing air stream. A typical probe of portable digital exhaust gas analyzer is placed in and around the flame with the help of a multi-direction traversing mechanism to measure emissions such as un-burnt hydrocarbons, carbon monoxide and carbon dioxide. Since ethanol readily mixes with water, emission characteristics of ethanol-water blends are also studied. For comparison purpose, emissions from pure ethanol diffusion flames are also presented. A simplified theoretical analysis has been carried out to determine equilibrium surface temperature, composition of the fuel components in vapor-phase and heat of reaction of each blend. These theoretical predictions are used in explaining the emission characteristics of flames from ethanol blends. (author) This paper presents the results of an experimental study of flow structure in horizontal equilateral triangular ducts having double rows of half delta-wing type vortex generators mounted on the duct's slant surfaces. The test ducts have the same axial length and hydraulic diameter of 4 m and 58.3 mm, respectively. Each duct consists of double rows of half delta wing pairs arranged either in common flow-up or common flow-down configurations. Flow field measurements were performed using a Particle Image Velocimetry Technique for hydraulic diameter based Reynolds numbers in the range of 1000-8000. The secondary flow field differences generated by two different vortex generator configurations were examined in detail. The secondary flow is found stronger behind the second vortex generator pair than behind the first pair but becomes weaker far from the second pair in the case of Duct1. However, the strength of the secondary flow is found nearly the same behind the first and the second vortex generator pair as well as far from the second vortex generator pair in the case of Duct2. Both ducts are able to create a counter-rotating and a second set of twin foci. Duct2 is able to create the second set of twin foci in an earlier streamwise location than Duct1, as these foci are well-known to their heat transfer augmentation. A larger vortex formation area and a greater induced vorticity field between vortex pairs are observed for Duct2 compared with Duct1. As the induced flow field between the vortex pairs increases the heat transfer, and as the flow field between the vortex cores is found larger in the case of Duct2, therefore, it is expected to obtain better heat transfer characteristics for Duct2 compared with Duct1. (author)

• OSTI ID: 21390715
• Journal Information: Experimental Thermal and Fluid Science, Vol. 35, Issue 1; Other Information: Elsevier Ltd. All rights reserved; ISSN 0894-1777
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
ETHANOL
FOSSIL FUELS
EMISSION
POROUS MATERIALS
VAPORS
FLAMES
CARBON DIOXIDE
CARBON MONOXIDE
REACTION HEAT
WATER
AIR
COMPARATIVE EVALUATIONS
MIXTURES
DIFFUSION
HYDROCARBONS
SPHERES
EQUILIBRIUM
FORECASTING
PARTICLES
COMBUSTION PROPERTIES
CHEMICAL COMPOSITION
Blended fuels
Infusion pumps analyzer