GAS-TURBINE EXHAUST EMISSIONS MONITORING USING NONINTRUSIVE INFRARED-SPECTROSCOPY

Infrared (IR) spectra of the exhaust emissions from a static gas turbi ne engine have been studied using Fourier Transform (FT) spectroscopic techniques. Passive detection of the infrared emission from remote (r ange similar to 3 m) hot exhaust eases was obtained nonintrusively usi ng a high spectral resolution (0.25 cm(-1)) FTIR spectrometer. Remote gas temperatures were determined from their emission spectra using the total radiant flux method or by analysis of rotational line structure . The HITRAN database of atmospheric species was used to model the emi ssion from gas mixtures at the relevant temperatures, The spatial dist ribution of molecular species across a section transverse to the exhau st plume similar to 10 cm downstream of the jet pipe nozzle was studie d using a tomographic reconstruction procedure. Spectra of the infrare d emission from the plume were taken along a number of transverse line s of sight from the centerline of the engine outwards. A mathematical matrix inversion technique was applied to reconstruct the molecular co ncentrations of CO and CO2 in concentric regions about the centerline, Quantitative measurement of the molecular species concentrations dete rmined nonintrusively were compared with results from conventional ext ractive sampling techniques.