RES Introduced Through Flame Image Processing and Visualization of 3-D Temperature Distribution in a Coal-Fired Boiler Furnace

It is possible to have a quick, high-quality monitoring, diagnosis and control system for the safe combustion process of a utility boiler with high efficiency. Compared with the delay characteristic of the steam response to the fuel or air disturbance into the furnace, the Radiant Energy Signal (RES) can reflect more quickly the combustion condition. Using a novel flame image processing technique, the 3-D combustion temperature distribution can be visualized and RES can be detected in real-time. So, a kind of control strategy to optimize the boiler combustion process and to improve the unit load control quality is feasible on the basis of RES. RES measuring system is developed according to the measuring theory of furnace flame images. 3-D temperature distribution and RES can be obtained transiently. In-situ experiments have been done to study the change of RES as regulating capacity of burners among different layers, disturbing the fuel mass flow rate, adjusting secondary air register, changing over-fire air and tilt angle in a 1025t/h fossil-fired boiler. Furthermore, the boiler efficiency and NO_x emission have also been analyzed. The result shows that the dynamic response characteristic of RES is ideal to improve the combustion control quality of the unit.