Design And Performance Analysis Of Carbon Content In Fly Ash For Measuring System Using Loss-on-ignition

The carbon content of fly ash is the main economic operation index and technical indicator in the rear of coal-fired boiler flue of the thermal power plant. This parameter is directly used to guide the adjustment of combustion and optimize the operation in the boiler and it is an indispensable raw data to calculate the boiler efficiency and evaluate the merit of combustion. Besides, the coal air ratio could be reasonably adjusted by monitoring the carbon content of fly ash, which contributes to improving power generation, reducing generation costs and enhance the "bidding" capacity. Thus, it is markedly meaningful for design and performance analysis of the monitoring system for carbon content in fly ash. Aiming at the carbon content of fly ash in the rear of coal-fired boiler flue, the main contents of this paper are performed as follows:(1) First of all, a detailed explanation of each constituent part of the intelligent actuator of loss-on-ignition(LOI) test on-line measurement system of unburned carbon in fly ash was made, namely controlled device, control unit and software system. Among them, several parts were mainly completed, including boom(manipulator) improvement, the selection and installation of stepper motors, sensors and the modules in the system. Finally, the action logic was determined and the control program was compiled, based on which a complete system was set up.(2) By comparing the rotary disc fly ash carbon meter used in power plant with the cantilever ash carbon meter improved in this paper, it proved that the designed ash carbon meter avoids some existing problems and significantly improved the monitoring performance. The main contents included: using the designed tester to actually measure and acquire the cycle data and carbon content data of fly ash in two power plants. After that, the measured data were processed. By using the detection accuracy and economic benefit as the evaluation index, economy and effectiveness of the designed ash carbon meter were further verified.