Gas temperature and radiative heat transfer in oxy-fuel flames

Other conference contribution, 2012

This work presents measurements of the gas temperature, including fluctuations, and its influence on the radiative heat transfer in oxy-fuel flames. The measurements were carried out in the Chalmers 100 kW oxy-fuel test unit. The in-furnace gas temperature was measured by a suction pyrometer and by an optical system based on FTIR-spectroscopy. The radiation intensity was measured by a Narrow Angle Radiometer and the gas radiation was calculated with a Statistical Narrow Band model. The overall agreement between the two temperature measurement techniques was good. The optical system showed a lower temperature than the suction pyrometer in the low velocity regions of the furnace, a difference which is likely to be an effect of the purge gas added in the optical probe. The measured temperature fluctuations were evaluated by modeling of the gas radiation. The influence from the measured fluctuations on the radiative heat transfer shows no effect of turbulence-radiation interaction. However, by comparing with temperature fluctuations in other flames it can be seen that the fluctuations measured here are relatively small. Further research is needed to clarify to which extent the applied methods can account for the turbulence-radiation interaction in the investigated flame.