Print Email Facebook Twitter Flamelesss combustion characteristics in a lab-scale furnace Title Flamelesss combustion characteristics in a lab-scale furnace Author Huang, X. (TU Delft Fluid Mechanics) Tummers, M.J. (TU Delft Fluid Mechanics) Roekaerts, D.J.E.M. (TU Delft Fluid Mechanics) Date 2017 Abstract Flameless combustion, named as Moderate or Intense Low-oxygen Dilution (MILD) combustion or high-temperature air combustion (HiTAC), is a promising technology to improve the thermal efficiency while suppressing NOx formation in combustion systems. Flameless combustion can occur when fresh air (and/or fuel) streams are sufficiently diluted by entrained combustion products before reactions take place. It has recently been experimentally studied on laboratory-scale setups because of scientific challenges, environmental concerns and its potential industrial applications. Some burning features in flameless combustion have been observed in jet-in-hot-coflow burners which use hot coflows generated by a secondary burner or diluting air with N2 or/and CO2 to mimic the diluted air which is actually diluted by burnt gases entrainment in furnaces. With the help of highspeed cameras, the time-resolved studies on such burners have been done experimentally. E. Oldenhof et al. [1] reported that the jet-in-hot-coflow flame is stabilized by autoignition kernels and the entrainment of hot oxidizer plays an important role in the formation of autoignition kernels[2]. As O2 level in coflow is reduced, reaction zone becomes less intense leading to a greater degree of partial premixing in these flames[3]. P. R. Medwell et al.[4] also concluded that large-scale vortices can lead to a weakening of the flame front or even local extinction leading to a form of partial premixing, and may contribute to the stabilization of the flameless combustion reaction zone. With low level (5% by volume) hydrogen addition in the fuel, the flame also exhibits autoignition kernels, but this was not observed at higher level (10% and 25%) hydrogen addition cases[5]. However, how can these findings be related to the flames in a furnace is still unclear because of the lack of similar experimental observations in furnace. To reference this document use: http://resolver.tudelft.nl/uuid:2e3de61c-bc03-491d-a4c1-e4e292c9e69b Event Combura 2017, 2017-10-11 → 2017-10-12, Soesterberg, Netherlands Part of collection Institutional Repository Document type abstract Rights © 2017 X. Huang, M.J. Tummers, D.J.E.M. Roekaerts Files PDF Combura2017_BoA2.pdf 1.69 MB Close viewer /islandora/object/uuid:2e3de61c-bc03-491d-a4c1-e4e292c9e69b/datastream/OBJ/view