“…However, all the heat flux values given in Fig. 7 are lower than those reported for PC boilers (see for example (Seltzer et al, 2007;Xu et al, 2000;Butler and Webb, 1991)) and within the ranges reported in the literature for oxy-fuel conditions (Seddighi Khavidak et al, 2015) and air-fired conditions (Seddighi Khavidak et al, 2015;II'chenko et al, 1968;Grewal, 1981;Huilin et al, 2000;Xie et al, 2003aXie et al, , 2003b in CFB boilers. One should note that the detailed description of the role and share of convective and radiative heat transfer in the air-and oxy-fired CFB furnace is given in detail in Seddighi Khavidak et al (2015) where it is shown that the radiative heat extraction is more than 70% of total heat extraction in the furnace while the solids radiation dominates the gas radiation in conditions relevant for CFB combustion.…”