Research On Microwave Detection Technology Of Carbon Content In Fly Ash

Electric power industry is the important foundation of economic and social development. At present, coal is the mainly fuel in the power generation. But the transportation cost is high as the uneven distribution of coal resources in China. Coal is non-renewable resources, and the burning of the coal will impact the environment. Therefore, reduce the consumption of coal to reduce power generation cost and the pollution of the environment has important significance.The carbon content in fly ash is one of the main economic indicators and technical indicators of coal-fired boiler; it marks the degree of burning coal in a boiler. Therefore, detection of carbon content of fly ash boiler flue gas is a good understanding of the boiler combustion conditions. Generally the power plant usually used calcination method to test the carbon content of fly ash in the past,but as a result of the test need time is longer, the testing result lag for a few hours, so can’t guide the adjustment of boiler combustion. In recent years, with the continuous development of microwave detection technology, all kinds of microwave antenna and microwave devices have been widely used, microwave detecting technology has been widely used.This paper introduces the interaction between microwave and dielectric theoretical basis, research methods and development station. By studying the propagation rules of microwave in the dielectric, it is found that different carbon content of fly ash will cause the change of dielectric constant. And both the microwave amplitude attenuation and microwave phase shift have relation with the dielectric constant too. Therefore, the carbon content of fly ash has a determined corresponding relation with the microwave amplitude attenuation and microwave phase shift. On this basis, the fly ash carbon content is established on the mathematical model of microwave attenuation and phase shift.This paper analyzes the principle and the characteristic of microwave detecting technology of fly ash carbon content, and a microwave detection system of fly ash carbon content is designed. The whole system is mainly composed of fly ash sampling system and microwave measurement system. Fly ash sampling system is mainly composed of gray system and road system, its main function is making the fly ash samples separated from flue gas, and then goes into the microwave pipe for testing; Microwave measurement system is mainly composed of microwave transmission unit and amplitude-phase measurement unit. The main function is detecting the microwave attenuation and phase shift. Finally the system is used in the field and the experimental results show that the detection accuracy of the system is high.