Electronic temperature sensor arrays for gas turbine components

Abstract

The current master's thesis presents the development of a new temperature sensing technology for gas turbine components.The proposed sensor array allows real time simultaneous measurements of temperature at multiple locations, using only two communication leads. Frequency modulation is used to multiplex the signals of more than ten temperature sensors through common wires. At every point of reading, silicon carbide (SiC) microelectronic oscillators generate the required waveforms, at frequencies that are temperature dependent. Those oscillators are fed with a common DC power source, and add their signals together by current addition into the power supply leads.The multiplexed signal can be recorded using only one acquisition channel, and be analyzed in the frequency domain to deduce temperatures.The resulting sensor array can be seen as a temperature sensitive wire, including two leads, and multiple integrated microscopic oscillators. It is compact, and alleviates the problem of lead routing, which is especially cumbersome in small business or regional aircraft engines. SiC microelectronics promising to be operable at temperatures above 700[degrés Celcius], the proposed sensor array could be used inside cooled turbine airfoils and shrouds, in moderate testing and flight cruising conditions, or in compressor components. It offers new possibilities in ground testing, vehicle health monitoring, and engine control. Validation tests were conducted using macroscopic high temperature oscillator prototypes. Two oscillators were built using high temperature discrete components, and were tested in an oven up to 180[degrés Celcius].The results of those tests are presented in this thesis.