Research on Mathematical Model and Process Parameter Optimization of Rotary Hearth Furnace Process Toward Energy and Cost Saving

To explore the solutions of saving energy and cost of the rotary hearth furnace (RHF) direct reduction process, this paper constructed an energy consumption model, an economic evaluation model, and a carbon emission calculation model of the RHF direct reduction process. According to the actual production conditions of a steel plant, the influence of combustion air temperature and oxygen enrichment rate on the energy consumption, cost, and carbon emission of the RHF direct reduction process were studied. The calculation results show that for every 50 °C increase in the combustion air temperature, the process energy consumption, comprehensive cost, and carbon emission reduce by about 11 kgce, 42 CHY, and 44 kg, respectively. For every 2 pct increase in the oxygen enrichment rate of the combustion air, the corresponding values are about 10 kgce, 26 CHY, and 37 kg, respectively. In addition, the mathematical model established in this paper can be used to calculate the process energy consumption, cost, and carbon emissions under different raw material and fuel conditions, which is of great theoretical significance for the green and low-carbon transformation of the RHF direct reduction process.