|
A point-and-shoot, passive remote sensing technology is highly desired to accurately monitor the combustion efficiency
(CE) of petrochemical flares. A Phase II DOE-funded SBIR effort is being led by Spectral Sciences, Inc. to develop
the methodologies needed to enable remote CE measurements via spectral remote sensing. Part of this effort entails
standing up a laboratory-scale flare measurement laboratory to develop and validate CE measurements. This paper
presents an overview and summarizes current progress of the Air Force Institute of Technology's (AFIT) contribution to
this multi-organization, two-year effort. As a first step, a Telops Hyper-Cam longwave infrared (LWIR, 750-1300cm-1 or
7.7-13.3μm) imaging Fourier-transformspectrometer (IFTS) is used to examine a laminar, calibration flame produced by
a Hencken burner. Ethylene and propane were combusted under several different fuel/air mixing ratios. For each event,
300 hyperspectral datacubes were collected on a 172(W)×200(H) pixel window at a 1.5cm-1 spectral resolution. Each
pixel had approximately a 1.5×1.5mm2 instantaneous field-of-view (IFOV). Structured emission is evident throughout
the combustion region with several lines arising from H2O; other lines have not yet been assigned. These first known
IFTS measurements of a laminar Hencken-burner flame are presented along with some preliminary analysis. While the
laminar flame appears stationary to the eye, significant flame flicker at a fundamental frequency of 17Hz was observed
in the LWIR, and this is expected to complicate spectral interpretation for species concentrations and temperature
retrieval. Changes to the fuel-air ratio (FAR) produced sizable changes in spectral intensity. Combustion spectra of
ethylene and propane corresponding to ideal FAR were nearly identical.
|
