Adaptation of combustion products emissivity factor to the 1000...2000 K temperature interval

The accuracy of calculations of heat transfer caused by the emission from a high-temperature gas flow during the combustion of natural fuels significantly depends on the accuracy and representation of data on thermal and physical properties of gases, as well as the value of a radiant heat flux. Th reliable experimental data helped to generate the dependencies that allow performing calculations of emissivity factor for combustion products. The accuracy of the calculable approximation of experimental data in the two-factor function - optical density of the gas and its temperature - has been determined. The adaptation of parameters in a ratio for calculating the attenuation ratio and the Buger number has been carried out based on the updated experimental data. The range of application of the obtained results for the intense combustion zone as well as for the main combustion chamber volume of a boiler unit has been considered. This gives the possibility to determine boundary conditions for these zones of the boiler unit. Previously developed mathematical model with a triple-component pattern, which allows dividing the influence of flare continuum and combustion gases, is applicable for the intense combustion zone. The heat transfer in the main combustion chamber volume is described within the heat transfer paradigm, which allows accounting for the configuration of the combustion chamber as well as the efficiency of heat emission to the waterwall surfaces.