Combustion control by means of a photodiode

in Proceedings of the 25th Task Leaders Meeting (TLM) of the IEA Implementing Agreement "Energy Conservation and Emissions Reduction in Combustion" (2003, September)

The objective of this work was to assess the feasibility of a photodiode to control combustion, instead of a spectrometer (which is an expensive sensor to be used in commercial burners). For that purpose ... [more ▼]

The objective of this work was to assess the feasibility of a photodiode to control combustion, instead of a spectrometer (which is an expensive sensor to be used in commercial burners). For that purpose, the flame emission has been measured in a hot-water boiler fired with light fuel-oil, whose nominal output power goes up to 370 kW. The parameters investigated were: overall air excess, combustion air distribution, burner power and atmospheric conditions. High influence of air distribution on the flame emission was detected by the diode, since it modifies directly the mixing quality reducing rich-fuel regions where soot can be formed. Low influence of air excess and burner power was found. When these parameters increase, the flame emission decreases. This behavior is explained by the better mixing attained at high burner power and at high air excess. However the high emission level observed at low firing rate can be reduced with a good burner adjustment. With the photodiode, it was possible to find the optimum air excess value where NO, CO and soot are as low as possible. As the photodiode measures locally in the flame, results were compared with images obtained with a CCD camera. Finally, these results are in good agreement with those obtained previously with the spectrometer. [less ▲]

Acoustic Pyrometry: A non-intrusive Technique for Temperature measurements in a Combustion Chamber (2)

Report (2003)

Influence of Dimethoxymethane (DMM) Addition in Light Fuel Oil on the Flame Emission in a Domestic Hot water Boiler : Part II

Report (2002)

EXPERIMENTAL INVESTIGATION OF NOx FORMATION MECHANISMS IN A FUEL-OIL BOILER

Conference (2002, June)

The work whose results are reported in this paper was aimed at gathering information that can give a deeper insight into the structure of a diffusion fuel-oil flame. This allows us to get a better ... [more ▼]

The work whose results are reported in this paper was aimed at gathering information that can give a deeper insight into the structure of a diffusion fuel-oil flame. This allows us to get a better understanding of the combustion process and thus a correct basis for combustion modeling, focused on NOx formation. In order to attain the objective, axial and radial temperature, NOx and O2 concentration profiles have been measured in the flame for high and low firing rates of a domestic hot water boiler (around 424 and 270 kW respectively). Temperature was measured by means of two B-type thermocouples (diameters 0.5 and 0.35 mm) and NOx and O2 concentrations using a classical gas analyzer. Maximum NOx emissions (167 ppm at 424 kW and 134 ppm at 270 kW) were recorded in high oxygen concentration and low temperature zones of the flame ( ≈ 1000°C), where no thermal-NO can be formed. Flue gas recirculation and NOx destruction process is clearly demonstrated in the flame due to the higher NOx concentrations recorded in the combustion chamber near the burner exit than in the chimney. Near the burner exit NOx, O2 and temperature radial profiles are very unstable. Higher temperature fluctuations were detected with the small thermocouple in the measurements at 270 kW. The contribution of the three types of NOx formation mechanisms was obtained using a simplified model. According to these results, the majority of NOx in this type of flame could be caused by the prompt-NO mechanism, formed in the zone close to the burner exit at the location where secondary combustion air is introduced. [less ▲]

SiC-UV Photodiode for Combustion Control

Report (2002)

UV-PHOTODIODE SELECTION FOR COMBUSTION CONTROL

Report (2002)

ACOUSTIC PYROMETRY : A NON-INTRUSIVE TECHNIQUE FOR TEMPERATURE MEASUREMENTS IN A COMBUSTION CHAMBER

Report (2001)

INFLUENCE OF DIMETHOXYMETYHANE (DMM) ADDITION IN LIGHT FUEL OIL ON THE FLAME EMISSION IN A DOMESTIC HOT WATER BOILER

Report (2001)