COMBUSTION TURBINE FLASHBACK SENSING SYSTEM EMPLOYING FIBER BRAGG GRATING SENSORS

• Main Author: JOHNSTON ROBERT T
• Format: Patent
• Language: English
• Published: 06.03.2014
• Subjects: MEASURING; MEASURING QUANTITY OF HEAT; MEASURING TEMPERATURE; PHYSICS; TESTING; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR

A combustion turbine flashback sensing system with a sensor cable that includes an optical fiber having at least one and preferably multiple fiber Bragg grating (FBG) temperature sensors along the fiber. The sensor cable is oriented in a combustor turbine upstream a combustion zone, so that it is capable of sensing temperature at multiple sensing points within the combustor. A protective conduit having a first thermal conductivity circumscribes the optical fiber. A sensor shield is oriented in circumferential proximity to the FBG temperature sensor. It is preferable that each such sensor has an associated sensor shield. The sensor shield has a thermal conductivity greater than the conduit thermal conductivity. The sensor shield facilitates FBG sensor rapid thermal response, with sufficient thermal and mechanical shielding to isolate the sensor from harsh operating conditions within the combustor, while the less thermally conductive conduit provides greater isolation protection for the cable structure.