A new method for constructing radiative energy signal in a coal-fired boiler

In this paper, a systematic method to construct the radiative energy signal (RES) is proposed based on an image-processing-based combustion monitoring and control system with 16 high-temperature flame image detectors with CCD cameras mounted in a 300 MWe power generation plant. In this method, the gray value in GSU (Grey-Scale Unit) in every image is first transformed to a raw RES with the same unit and scale for the power output, and then a final RES is obtained after compensation for the load. RES signals thus calculated were found to be higher or lower than the measured power output indicating deviation of the fuel feed rate from optimal values leading to undesirable combustion conditions in the plant. As the load either increases or decreases in a large range, the RES values consistently and even synchronously varied based on increased or decreased loads. RES is successfully used to optimize the heat value signals of the power plants. The results show that RES constructed by the proposed method reveals the fluctuating level of energy in the boiler and may be used to monitor and control the operation of the system.