Temperature measurement system for furnaces

A method of monitoring and controlling a furnace, comprising:

• obtaining radiance measurements from a plurality of region of interest (ROIs) in a furnace utilizing a plurality of thermal imaging cameras;
• measuring a surface temperature of the furnace using a radiance measurement obtained from an ROI selected from the plurality of ROIs, including:
• determining an effective background radiance affecting the selected ROI utilizing radiance measurements obtained from ROIs different from the selected ROI;
• obtaining a compensated radiance by removing the effective background radiance from the radiance measurement obtained from the selected ROI;
• converting the compensated radiance to the measured surface temperature of the furnace, wherein the radiance measurement obtained from the selected ROI is obtained from a plurality of pixels in the ROI, averaged over at least one selected from the group consisting of space and time;
• and
• making local adjustments to a fuel flow to burners to control the surface temperatures of the furnace.

A system for measuring furnace temperatures, comprising:

• a plurality of thermal imaging cameras and a processing unit configured to obtain radiance measurements from a plurality of regions of interest (ROI) of a furnace using the plurality of thermal imaging cameras, wherein
• the thermal imaging cameras are utilized to measure a surface temperature of the furnace using a radiance measurement obtained from an ROI selected from the plurality of ROIs, including:
• determining an effective background radiance affecting the selected ROI using a weighted average of radiance measurements obtained from the ROIs that are different from the selected ROI and are within a hemisphere in front of the selected ROI;
• the processing unit is employed to obtain a compensated radiance by removing the effective background radiance from the radiance measurement obtained from the selected ROI;
• and
• converting the compensated radiance to the measured surface temperature of the furnace, wherein the radiance measurement obtained from the selected ROI is obtained from a plurality of pixels in the ROI, averaged over at least one selected from the group consisting of space and time.