Efficiency of flare flames in turbulent crosswind

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Title Efficiency of flare flames in turbulent crosswind
Creator Gogolek, Peter E.G.; Hayden, A.C.S.
Publication type report
Publisher American Flame Research Committee (AFRC)
Program American Flame Research Committee (AFRC)
Date 2010
Description Flares are used for the safe, clean and economical disposal of waste gases, whether in upstream oil production (solution gas flares), refineries, gas plants or other chemical processing facilities. Elevated flares are exposed to all the weather patterns, perhaps the most important is the crosswind. An important parameter in the flare flame behaviour is the ratio of the fuel jet momentum flux to the crosswind momentum flux. When this ratio is less than unity, the flame is stabilised by a recirculating eddy downwind of the flare pipe. This paper is concerned with these wake-stabilised flames. The CETC Flare Test Facility (FTF) was constructed to address the questions of performance of solution gas flares and in response to limited field trials that indicated the possibility of very low combustion efficiencies under certain conditions. The FTF consists of a high capacity fan feeding through flow straighteners into the working section, 1.2m wide and 8.2m long. The variable ceiling height is adjustable to 1.5m, 1.8m, 2.1m and 2.6m, permitting a very wide range of crosswind speeds up to 45 km/h. The flare pipe is situated near the front of the working section. Model solution gases are produced from natural gas, propane, carbon dioxide and nitrogen. Liquid droplets can be injected into the fuel gas to simulate the entrainment of liquids. The basic airflow (wind) in the working section has been designed to have very low turbulence intensity. Atmospheric wind is a turbulent shear flow with intensity around 7%. While it is not possible to exactly reproduce atmospheric turbulence in the FTF, using different grids can produce a range of turbulence intensities and integral length scales. The paper will discuss how this grid-generated turbulence relates to the turbulence properties of atmospheric wind. The flare flame efficiency is measured by the conversion of carbon in the fuel to carbon dioxide. Fuels tested are natural gas, propane, and mixtures of these. Conversion efficiency is lowest for pure natural gas, and increases with the amount of propane. However, conversion efficiency decreases significantly with the increase of turbulence intensity of the crosswind, which has implications for existing and novel strategies to improve flare performance. These results are explained by the lower flammability limits of the gas mixtures.
Type Text
Format application/pdf
Language eng
Rights (c) American Flame Research Committee (AFRC)
OCR Text Show
Metadata Cataloger CLR; AM
ARK ark:/87278/s6bp54v8
Relation has part Gogolek, P. E. G., & Hayden, A. C. S. (2010). Efficiency of flare flames in turbulent crosswind. American Flame Research Committee (AFRC).
Format medium application/pdf
Rights management American Flame Research Committee (AFRC)
Setname uu_afrc
Date Created 2020-02-11
Date Modified 2020-02-11
ID 1525679
Reference URL https://collections.lib.utah.edu/ark:/87278/s6bp54v8