Pitaksa Suvarnakuta . High temperature air combustion applied to incineration . Doctoral Degree(Mechanical Engineering). King Mongkut's University of Technology North Bangkok. Central Library. : King Mongkut's University of Technology North Bangkok, 2008.
High temperature air combustion applied to incineration
Abstract:
The objective of this study is to investigate the application of High Temperature
Air Combustion (HiTAC) in incineration of solid waste. The studies are divide to four
parts, i), to study the effect of preheating wall temperature and primary air supply in
combustible gas emissions, ii), to study the burner operation characteristics and fuel
consumption, iii), to study the effects of preheated secondary combustion air at
different temperatures, iv), to study the effects of preheating diluted secondary
combustion air at different conditions. The experiment was done in 17-kW lab-scale
controlled-air incinerator. The results from the first part showed that the highest
combustible gas concentration was measured in the case of 10% primary air flow and
preheated wall temperature at 700oC with 3.45 MJ/Nm3 of HHV. In the second part of
the study, it was observed that preheated secondary combustion air affect to a burner
operation characteristics and therefore reduce fuel consumption at a factor of 7.7 and
22.9% at preheating air temperatures of 500oC and 1000oC, respectively compared to
normal air. The third part, it was observed that the combustion with higher preheated
secondary combustion air temperature resulted in an increase in average flame
temperature, and a reduction in supplementary fuel consumption, but caused higher
NOX emissions. The maximum percentage of energy saved and the increase in NOX
emission that occurred with the preheating secondary combustion air at 900oC are
40% and 38%, respectively. In the last part of the study, the preheated diluted
secondary combustion air can be saved energy between 26% to 48% compared to
non-preheated diluted secondary combustion air with the overall range of NOX
reduction was 28% to 38% compared to non-diluted condition. It can be concluded
that in order to obtain higher average flame temperature than non-preheated and
diluted condition for the purpose of supplementary fuel saving, proper preheated
secondary combustion air temperatures should be at least 532oC and 621oC,
respectively for 17% and 15% oxygen concentration. The optimum point of this
experimental set up and testing range is preheated secondary combustion air at 900oC
and diluted at 17% oxygen concentration and the operating ranges are preheated
secondary combustion air above 532oC and diluted secondary combustion air between
15% and 21% oxygen concentration. In summary, HiTAC can be applied to
incineration process for energy saving with lower emissions.
King Mongkut's University of Technology North Bangkok. Central Library