Abstract:

In this paper , fundamentals of laser-induced breakdown spectroscopy (LIBS) studies are briefly reviewed first , including the experimental set-up , the qualitative and quantitative analysis methods for the spectrum. Then , the studies on combustion diagnosis by LIBS are introduced in detail. Moreover , a quantitative analysis of residual carbon in fly ash is carried out , and the characteristics and composition of coal are finally analyzed. The results show that (1) the carbon content in fly ash measured by LIBS accords well with that measured by the traditional method of W eight -Combustion; (2) the coal samples with different coalification degrees show different plasma time-resolved spectral characteristics; (3) in the same experimental conditions , the plasma temperature increases with the coalificatÏon degree; and (4) the coal content measured by LIBS coincides with that measured by the traditional method. The present study verifies the feasibility of combustion diagnosis by LIBS and lays a foundation for further studies and experiments of combustion diagnosis.

Key words: laser-induced breakdown spectroscopy, combustion diagnosis, quantitative analysis, fly ash, coal