A NON-INTRUSIVE TURBINE TEMPERATURE FOR DIAGNOSTIC AND MONITORING APPLICATIONS

ACCURATE MEASUREMENTS OF TURBINE BLADE TEMPERATURES ARE IMPORTANT IN MONITORING TURBINE HEALTH AND PERFORMANCE AND IN DIAGNOSING PROBLEMS. CURRENT INTRUSIVE AND OPTICAL TECHNIQUES HAVE SHORTCOMINGS. THERMOCOUPLES HAVE PROBLEMS WITH DURABILITY AND ACCURACY. TWO COLOR PYROMETRY LSO ENCOUNTERS PROBLEMS WITH ACCURACY DUE TO INTERFERENCE BY REFLECTED RADIATION AND PARTICULARLY REFLECTED EMISSION FROM THE COMBUSTOR. A MEASUREMENT TECHNIQUE IS PROPOSED WHICH IS INSENSITIVE TO REFLECTED EMISSION, AND, THEREFORE, CAPABLE OF MUCH HIGHER ACCURACIES. THE TECHNIQUE DETERMINES THE COMPONENT TEMPERATURES BY MEASURING THE CHANGE IN INFRARED EMISSION PRODUCED BY IRRADIATION FROM A 1 US LASER PULSE. THE SURFACE TEMPERATURE DETERMINATION IS NOT SENSITIVE TO EITHER THE INTENSITY OR THE DURATION OF THE LASER PULSE. THE MEASUREMENT SYSTEM CAN BE RUGGEDIZED FOR USE ON AN ENGINE BY COUPLING THE LASER AND DETECTORS WITH THE ENGINE OPTICS BY OPTICAL FIBERS. THE SYSTEM IS CAPABLE OF AN ACCURACY OF 10 DEG F IN THE MEASUREMENT OF BLADE TEMPERATURES IN THE RANGE OF 1000 DEG F TO 2500 DEG F.