System and method for detecting carbon content of fly ash under dynamic condition of hollow metal waveguide

Abstract

The invention provides a system and method for detecting the carbon content of fly ash under the dynamic condition of a hollow metal waveguide. The system comprises a bypass measuring unit and a measuring device, wherein the bypass measuring unit and the measuring device can measure the fly ash from a flue in real time. The measurement method comprises the steps of introducing a standard ash sample of the same kind of coal into the hollow metal waveguide for measurement to obtain S21 amplitude or phase data of the standard ash sample, and fitting the data to obtain a fitting relational expression of the standard ash sample at different frequency points; starting an air compressor to introduce the fly ash in the flue into the hollow metal waveguide through an ejector and a cyclone separator, selecting any frequency point through a vector network analyzer to test the introduced fly ash to obtain S21 amplitude or phase data of the measured ash sample, and substituting the S21 amplitude orphase data into the relational expression to calculate the carbon content. Compared with the prior art, the method has higher resolution and test precision, test results of different carbon contentsare stably and obviously distinguished, the carbon content is increased every 2%, the corresponding S21 amplitude parameter is changed by 15-20 degrees, and the precision is better.

Description

technical field [0001] The invention relates to the field of testing the electromagnetic parameters of the carbon content of the fly ash at the tail of a thermal power plant, in particular to a system and method for detecting the carbon content of the fly ash under the dynamic condition of a hollow metal waveguide. Background technique [0002] The carbon content of fly ash is an important parameter reflecting the combustion efficiency of boilers in thermal power plants. Accurate, timely and effective monitoring of the carbon content in fly ash is of great significance for adjusting boiler combustion and improving combustion efficiency. At present, a variety of measurement methods for carbon content in fly ash have been developed, which are mainly divided into two categories: physical measurement and soft measurement. Physical measurement is to use the physical and chemical characteristics of carbon flammability and high dielectric constant to detect the carbon content of fl...

AI Technical Summary

Problems solved by technology

It is understood that many power plants are still using the sampling method to detect fly ash samples. The following problems generally exist in the sampling method: when the ash sample enters the measurement chamber, the temperature drops sharply and condensation occurs, which blocks the measurement chamber with ash, and the tail smoke is not clear. Due to the characteristics and distribution of the flue gas flow field, the sampling is not representative, the influence of the fly ash concentration on the measurement results is ignored, and the additional equipment is complicated to increase the investment and maintenance costs of the equipment.

[0004] The existence of the above problems is difficult to meet the requirements of real-time and accurate detection of carbon content in fly ash in thermal power plants

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