System and a method for monitoring combustion and pollutants in a thermal plant by means of laser diodes

摘要

A system for monitoring combustion and pollutants developed in a combustion chamber comprising at least one longitudinal single mode laser diode emitting a beam of electromagnetic radiation with a frequency modulated around the resonance frequency of a specific spectral absorption line of a component of the combustion gases, means for directing the beam into the combustion chamber along a path through the combustion gases to a radiation sensor and processing means connected to the sensor in order to identify the temperature of the combustion gases and the concentration of the component with the specific absorption line by the measurement of the intensity of radiation transmitted at various frequencies in a region surrounding the resonance frequency.