Simultaneously reconstruction of inhomogeneous temperature and radiative properties by radiation image processing

This paper presented an experimental study on simultaneously reconstruction of three-dimensional temperature and inhomogeneous radiative properties distribution by radiation image processing in a 600 MWe supercritical arch-fired boiler. Two independent monochromatic radiation intensities extracted from the flame image were used to solve the temperature and radiative properties respectively by iteration, and provided a reasonable option for the radiative properties. Finally the convergent radiative properties were fixed for the on-line detection of temperature. The visualized temperatures obtained by the present method for different cases agreed well with those measured by infrared pyrometer at different locations, while the largest relative error was less than 4.60%. The three-dimensional temperature measurement results indicated that, the undershoot depth of flame was increased and the flame scoured the cold hopper when the F secondary air was downward sloping in the boiler. The present on-line temperature measurement method based on inhomogeneous radiative properties was reliable for the combustion diagnostic in the combustion industry, and would help to improve the awareness level of combustion in the supercritical arch-fired boiler.