Three-Dimensional Reconstruction Algorithm Of Furnace Flame Based On Inversion Calculation Of Thermal Radiation

The combustion flame in the power plant furnace is the most direct reflection of monitoring whether the combustion state is stable.Instability of combustion will lead to the reduction of efficiency of the combustion furnace,resulting in more pollutants,in extreme cases will occur fire extinguishing,and even cause explosion caused by accidents.Therefore,the temperature measurement in the power plant furnace to achieve three-dimensional reconstruction of the flame temperature field is of great significance for temperature monitoring,energy saving,emission reduction and safety protection.The application of three-dimensional reconstruction technology to analysis model objects,the surface features of objects and structural information is more and more widely.Especially in the field of flame temperature reconstruction,the analysis can make people study the flame temperature field and the degree of combustion more intuitively.Owing to the diversity and complexity of combustion flames in tangentially-fired furnaces,now there is limited research on the monitoring of flames in such furnaces.A three-dimensional reconstruction model of furnace flame temperature field is designed,and a temperature field calculation method based on radiation inversion is proposed in this dissertation.First,the CCD camera is processed by a spectroscopic device and a filtering device so as to obtain a 3-D synchronized filtered image of the flame image.The radiation intensity represented by the gray value of each pixel in the image can be expressed as the sum of the radiation intensities of the points in the longitudinal direction.According to the basic principle of thermal radiation,a three-dimensional reconstruction model of flame temperature field is constructed.According to the structural characteristics of a tangentially-fired furnace,the method of acquiring images of the flame field from four different directions is adopted,and it solves the shortcomings caused by hardware defects and the error caused by the radiation attenuation to a certain extent.For solving the nonlinear equations in the model inversion calculation,we transform it into an optimization problem,and an improved hybrid genetic algorithm is designed to solve the problem.The method guarantees the fast convergence of the temperature field inversion calculation.Finally,the inversion result is analyzed and the temperature measured by thermocouple is compared with inversion temperature,which verifies the effectiveness of the temperature field calculation method based on the radiation inversion and the inversion result is good.