System and method for monitoring a reactor system using optical fiber based sensors

A solid oxide fuel cell system, comprising:

• a solid oxide fuel cell stack including a number of solid oxide fuel cells, wherein each of the solid oxide fuel cells is structured to operate at a high temperature ranging from 500° C. to 1000° C.;
• and
• a sensor system structured to measure at least one of (i) a chemical composition of one or more reactants in a gas stream flowing through the solid oxide fuel stack, or (ii) a temperature of the gas stream flowing through the solid oxide fuel stack, the sensor system including an optical fiber sensing member including a monolithic in-fiber sensing element positioned inside one or more of the solid oxide fuel cells, wherein the monolithic in-fiber sensing element is structured to exhibit a change in one or more optical properties in response to changes in at least one of (a) the chemical composition of the one or more reactants and (b) the temperature of the gas stream, and wherein the monolithic in-fiber sensing element is structured to provide stable sensing at high temperatures ranging from 500° C. to 1000° C.;
• wherein the sensor system is structured to implement distributed sensing along the gas stream at a plurality of sensing locations along the monolithic in-fiber sensing element using a scattering based interrogation approach and without employing a plurality of in-fiber optic components in a core of the optical fiber sensing member such that the sensor system is configured to measure at least one of (i) the chemical composition of the one or more reactants with spatial resolution at the plurality of sensing locations, and (ii) the temperature of the gas stream with spatial resolution at the plurality of sensing locations.