Effects of air swirl on the combustion and emissions characteristics of a cylindrical furnace fueled with diesel-biodiesel-n-butanol and diesel-biodiesel-methanol blends

Confined flames are widely used in the industrial field. The flame characteristics can be strongly dominated by the combination of a burner and furnace geometries, which were not paid much attention before. In the present study, flow fields in confined flames are discussed in terms of the flame characteristics. The flow characteristics of confined flames have been investigated for propane nonpremixed flames in cylindrical furnaces. The effects of the inner diameter of the cylindrical furnace D1, the turbulence at the flame boundary, and the global equivalence ratio φ are examined in terms of the relation between the emission of NOx and the flow fields. The emission index of NOx, EINOx, decreases roughly with these parameters. The decrease in EINOx is thought to be related to the dilution of mixtures by the burned gas and the flame stretch. The dilution is attributable to vortices formed at the bottom of the furnace, and the flame stretch is attributable to the air velocity difference ΔUa created by two air nozzles. In the present study, it was found that the increases in D1, ΔUa, and φ enlarge and strengthen recirculation vortices to dilute the flame.

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222 An Experimental Investigation of NO_x Emission in High Air Temperature Combustion in Cylindrical Furnace : The Effect of the Distance Between the Fuel and Air Nozzles

The Proceedings of Conference of Tokai Branch ◽

10.1299/jsmetokai.2006.55.97 ◽

2006 ◽

Vol 2006.55 (0) ◽

pp. 97-98

Author(s):

HRISTOV ZVONKO ◽

SUSUMU NODA ◽

TAKASHI YASUE

Keyword(s):

Experimental Investigation ◽

Air Temperature ◽

Temperature Combustion ◽

Cylindrical Furnace

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Numerical Simulation of Natural Gas Combustion Process Using a One-Step and a Two-Step Reaction

Energy Conversion ◽

10.1115/imece2002-39312 ◽

2002 ◽

Cited By ~ 2

Author(s):

Angela O. Nieckele ◽

Moˆnica F. Naccache ◽

Marcos S. P. Gomes ◽

Joa˜o N. E. Carneiro ◽

Andre´ Augusto Isnard ◽

...

Keyword(s):

Experimental Data ◽

Natural Gas ◽

Combustion Process ◽

Chemical Species ◽

Reaction Model ◽

Gas Combustion ◽

First Case ◽

Natural Gas Combustion ◽

Cylindrical Furnace ◽

Global Reaction

The work evaluates the combustion of natural gas in a cylindrical furnace. The Generalized Finite Rate Reaction Model was selected for predicting the reactions. Two situations were considered. In the first case the combustion of the fuel was predicted by a single global reaction, and in the second case a two-step reaction was considered for predicting the combustion process. The conservation equations of mass, momentum, energy and chemical species were solved by the finite volume procedure, with the commercial software FLUENT. The turbulent flow was modeled by employing the two differential equation κ–ε model. The solutions obtained with the two reaction models, for the temperature and species concentration fields, were compared among them and against experimental data available in the literature. It was observed that the two-step reaction model represents better the physical phenomena, showing a better agreement with the experimental data.

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