Radiative heat transfer in splash and dilution zones of the pressurized oxy-fuel combustion CFB considering particle-dependent scattering

Abstract

• The radiative heat transfer in the oxy-fuel combustion PCFB is investigated. • The radiative heat transfer considering particle-dependent scattering is studied. • The importance of particle concentration on radiative heat transfer is summarized. • The mechanism of radiative heat transfer action in different regions is revealed. Radiative heat transfer is dominant in splash and dilution zones of the oxy-fuel combustion pressurized circulating fluidized bed (PCFB). However, the particle radiation fields interact with each other due to the high particle concentration. Moreover, the particle concentration distribution, the flue gas components and pressure change drastically due to pressurized oxy-fuel combustion technology. In this paper, the radiative heat transfer in splash and dilution zones of the oxy-fuel combustion PCFB is investigated when particle-dependent scattering is considered. The results show that the maximum error of the particle radiation model is less than 1% in predicting the incident heat flux at the wall when particle-dependent scattering is considered. The particle concentration distribution has a significant impact on the radiative heat transfer in splash and dilution zones of oxy-fuel combustion PCFB. The simplified particle concentration distribution model cannot capture the zero-source term phenomenon in the core region and has a large error in the annular region. In addition, the mechanism and importance of the flue gas composition and pressure on the radiative heat transfer in splash and dilution zones of oxy-fuel combustion PCFB are analyzed.