Experiences with Metal Fibre Burners at SINTEF Applied Thermodynamics: Effect ofFuel Type, Surface Load and Excess Air Ratio

摘要

Cylindrical, premix gas burners, based on the metal fiber material Bekitherm AC200 P1, have been tested at SINTEF Applied Thermodynamics. Two types have been tested; one with perforated plates inside the metal fiber material, to ensure a uniform distribution of the fuel-air mixture over the burner surface, and one with no perforated plates. The two burners gave very similar levels of pollutant emissions, but the one consisting of only a cylinder of Bekitherm material resulted in a poorer distribution of the flame over the burner surface. Generally, we have not been able to reproduce as low pollutant emission levels as given by ACOTECH, and higher excess air ratios have been required to obtain acceptable NOx and CO levels. Different devices for mixing of fuel and air have been tested, but different types of mixers resulted in no significant changes of the performance of the burners. Different fuel gases were also tested, this also resulted in minor changes. Experimental studies of the mixing process (mixing of fuel and air) were also performed to evaluate the effect of different geometries of the mixer. These studies showed that all our mixers worked well, and that major changes of the mixers resulted in insignificant improvements of the mixing of fuel and air.