Quantitative Analysis Of Carbon Content Of Fly Ash By Laser-Induced Breakdown Spectroscopy

Carbon content of fly ash is an important parameter affecting combustion efficiency of coal-fired boiler in power plant, which reflects the loss of mechanical incomplete combustion and influences the level of boiler process efficiency. Furthermore, accurate measure of carbon content of fly ash can benefit detection and modulation of boiler combustion, so that economical efficiency and security of unit can be increased. For a long time, carbon content of fly ash is measured by traditional method of Weight-Combustion, by the way of which carbon content is calculated through the weight differences between before and after combustion. However, this offline laboratory analytic method is operated by original sampling way, which costs much amount of work and long time. So that the result by this way always lags behind real-time work condition several hours even more, which can't be used to adjust combustion work condition in time, so that economical efficiency is influenced. This article introduces a new method, Laser Induced Breakdown Spectroscopy (LIBS), for the measure of carbon content of fly ash. First principle of LIBS is introduced. And the elements'mass concentration of the sample can be figured out by measuring wavelength and intensity of emission spectrum of plasma generated in LIBS experiment. Afterwards, the experiment system for measuring carbon content of fly ash by LIBS is introduced in detail, and principle and performance of every composing part is formulated. After that algorithm for data in computer is described. At last, by measuring and calculating a series of fly ash samples, the result shows that carbon content of fly ash measured by LIBS and method of Weight-Combustion are coincident well. It's authenticated that LIBS can be used to measure carbon content of fly ash as a new method.