AN ACOUSTIC PYROMETER SYSTEM FOR TOMOGRAPHIC THERMAL IMAGING IN POWER-PLANT BOILERS

The paper presents an acoustic pyrometry method for the reconstruction of temperature maps inside power plant boilers. It is based on measur ing times-of-flight of acoustic waves along a number of straight paths in a cross-section of the boiler; via an integral relationship, these times depend on the temperature of the gaseous medium along the paths . On this basis, 2D temperature maps can be reconstructed using suitab le inversion techniques, The structure of a particular system for the measurement of the times-of-flight is described, and two classes of re construction algorithms are presented, The algorithms proposed have be en applied to both simulated and experimental data measured in power p lants of the Italian National Electricity Board (ENEL), The results ob tained appear fairly satisfactory, considering the small data sets tha t it was possible to acquire in the tested boilers.