Exergy analysis and parameter optimization of sinter cooling process in vertical moving bed for waste heat recovery

Abstract A steady-state mathematical model is proposed to investigate the sinter cooling process in vertical moving bed, and the optimal parameter combination of vertical tank (VT) is obtained based on the maximum enthalpy exergy of cooling air (EECA) through the method of orthogonal experiment. The results show that, the air outlet temperature increases with increasing the air inlet temperature, bed inner diameter and height, and decreasing the air flow rate. The gas flow pressure drop basically increases linearly with increasing the air flow rate, air inlet temperature and bed height, and decreases exponentially with increasing the bed inner diameter. EECA can reach the maximum value with the increase of air flow rate and air inlet temperature. When the air flow rate exceeds a certain limit value, EECA also has a maximum value with the increase of bed height, while there is not a turning point for the change curve of EECA with the bed inner diameter. Taking the actual annual output of 360 m2 sintering machine as the research object, the optimal parameter combination of VT is 9 m for the bed inner diameter, 8 m for the bed height, 353 K for the air inlet temperature and 180 kg/s for the air flow rate, respectively.