In situ H2O and temperature detection close to burning biomass pellets using calibration-free wavelength modulation spectroscopy
2015 (English)In: Applied physics. B, Lasers and optics (Print), ISSN 0946-2171, E-ISSN 1432-0649, Vol. 119, no 1, 45-53 p.Article in journal (Refereed) Published
The design and application of an H2O/temperature sensor based on scanned calibration-free wavelength modulation spectroscopy (CF-WMS) and a single tunable diode laser at 1.4 μm is presented. The sensor probes two H2O absorption peaks in a single scan and simultaneously retrieves H2O concentration and temperature by least-squares fitting simulated 1f-normalized 2f-WMS spectra to measured 2f/1f-WMS signals, with temperature, concentration and nonlinear modulation amplitude as fitting parameters. Given a minimum detectable absorbance of 1.7×10-5 cm-1 Hz-1/2, the system is applicable down to an H2O concentration of 0.1 % at 1000 K and 20 cm path length (200 ppm·m). The temperature in a water-seeded lab-scale reactor (670-1220 K at 4 % H2O) was determined within an accuracy of 1 % by comparison with the reactor thermocouple. The CF-WMS sensor was applied to real- time in situ measurements of H2O concentration and temperature time histories (0.25 s time resolution) in the hot gases 2 to 11 mm above biomass pellets during atmospheric combustion in the reactor. Temperatures between 1200 and 1600 K and H2O concentrations up to 40 % were detected above the biofuels. ￼
Place, publisher, year, edition, pages
2015. Vol. 119, no 1, 45-53 p.
Renewable Bioenergy Research Atom and Molecular Physics and Optics
IdentifiersURN: urn:nbn:se:umu:diva-99509DOI: 10.1007/s00340-015-6026-zISI: 000352292500007OAI: oai:DiVA.org:umu-99509DiVA: diva2:787580
FunderBio4EnergySwedish Energy Agency