New weighted-sum-of-gray-gases radiation model for oxy-fuel combustion simulation of semi-coke from coal-based poly-generation

Abstract

Poly-generation based on coal pyrolysis achieves the graded utilization of coal. Further using the produced semi-coke for oxy-fuel combustion could achieve CO2 capture. In this study, a new weighted-sum-of-gray-gases radiation model was developed specifically for the numerical calculation of semi-coke oxy-fuel combustion. The applicable path-length range of the new model was 0.001–60 m, and the temperature range was 500–2,500 K. This model could accurately calculate the radiation characteristic parameters of the gas mixture for the semi-coke combustion. The results of the one- and two- dimensional cases show that the model could accurately predict the radiative heat transfer of the gas mixture. The average error of the radiative heat flux did not exceed 6.72 % and the error of the radiation source term did not exceed 10.96 %, while the maximum error of the radiation source term can reach 62.62 % for other WSGG models. Besides, the three-dimensional designed furnace simulation results show that the difference between the prediction of the outlet temperature of the furnace by the new and traditional models reached 110 K corresponds to a maximum difference of 26 % in radiation heat transfer. Therefore, the new WSGG model for numerical simulation of semi-coke oxy-fuel combustion is significant.