HIGH TEMPERATURE FIBER OPTIC SENSORS

TO OPTIMIZE SYSTEM EFFICIENCY, ADVANCED FOSSIL ENERGY SYSTEMS WILL REQUIRE HIGHLY SENSITIVE DEVICES FOR MEASURING TEMPERATURE IN REAL TIME UNDER OPERATING CONDITIONS. TO MAKE ACCURATE TEMPERATURE MEASUREMENTS IN THE EXTREME ENVIRONMENTS OF FOSSIL ENERGY SYSTEMS, NEW CONCEPTS IN SENSOR DESIGN WILL HAVE TO BE DEVELOPED. AVAILABLE THERMOMETRY DEVICES WILL NOT PERFORM RELIABLY IN THESE ENVIRONMENTS. FIBER OPTIC SENSORS OFFER A POSSIBLE SOLUTION, BUT AVAILABLE FIBERS OF GLASS OR SILICA CANNOT WITHSTAND THE OPERATING TEMPERATURES AND HARSH ENVIRONMENTS ENCOUNTERED. THIS PROJECT INVOLVES THE USE OF SINGLE CRYSTAL FIBER OPTICS THAT CAN BE USED AT THESE HIGH TEMPERATURES AND IN THESE SEVERE ENVIRONMENTS. HIGH TEMPERATURE REFRACTORY SINGLE CRYSTAL FIBERS OF ZIRCONIUM OXIDE, STRONTIUM OXIDE AND YTTRIUM OXIDE WILL BE GROWN WITH DIFFERENT DOPANTS IN THE TIP OF THE FIBER, TO SERVE AS A BLACKBODY RADIATION SOURCE. THE EMISSION FROM THIS SOURCE WILL THEN BE DETECTED AND ANALYZED TO DETERMINE THE TEMPERATURE OF THE FIBER TIP. THUS THE FINAL TEMPERATURE MEASUREMENT SYSTEM WILL CONSIST OF THE SINGLE CRYSTAL FIBER SENSING ELEMENT AND A MICRO-PROCESSOR-CONTROLLED ELECTRONIC ANALYSIS AND DISPLAY SUBSYSTEM. THE SINGLE CRYSTAL FIBERS WILL BE GROWN USING THE LASER-HEATED PEDESTAL GROWTH TECHNIQUE.