Numerical study of gas–solid counterflow heat transfer in sinter vertical cooling furnace based on energy and exergy analysis

In order to understand the energy and exergy transfer processes in the sinter vertical cooling furnace (SVCF) detailedly, and obtain the optimal structural and operating parameters for the SVCF, a numerical study was conducted to investigate the parametric effects on the gas–solid counterflow heat transfer in the SVCF based on the energy and exergy analysis. The results indicate that, the larger the gas mass flow and bed layer height are, and the lower the inlet gas temperature is, the larger the waste heat recovery (WHR) quantity and exergy destruction quantity are. The recyclable exergy quantity initially rises and subsequently reduces with rising the gas mass flow and inlet gas temperature, and rises with rising the bed layer height. Taking the actual production condition of the 360 m2 sintering machine as the calculation object, the optimal structural and operating parameters of SVCF are 195 kg/s for the gas mass flow, 343 K for the inlet gas temperature and 7 m for the bed layer height by selecting the WHR quantity and exergy destruction quantity in the SVCF as the objective functions. The rate of WHR for the SVCF can reach 83.02 % under the above optimal condition, showing the remarkable WHR effect. The research results have an important guiding significance for the design and operation of SVCF.