In 2019, according to the technological assignment of the Iron and Steel Institute (ISI), the reconstruction of the blast furnace (BF) No. 3 of PJSC «AZOVSTAL IRON & STEEL WORKS» was carried out for the long-term energy-efficient production of pig iron with using pulverized coal (PCI) up to 180 kg/t with a change in the profile according to the technological task of ISI. The design of the BF No. 3 profile corresponds to the best world solutions for furnaces efficiently working with pulverized coal, and the furnace was equipped with five mathematical models of ISI («Horn», «Mine», «Heat losses», «Loading», «Slag»). Specialists of ISI developed recommendations and carried out technological support for the operation of BF No.3, which made it possible to increase the removal of pig iron from the design 2.1 t/m3 to 2.27 t/m3 and achieved the best indicators in the blast furnace workshop in terms of coke and equivalent fuel consumption by increasing the productivity of the burden system, using a rational burden loading matrix, using a rational pressure drop in the furnace, which allows the maximum use of the power of the blower machine, forcing the furnace with technical oxygen and other measures. Using the heat power model of I.D. Semikin was made a comparative analysis of the best for six months indicators of thermal performance and technical and economic indicators of BF №3 of PJSC «AZOVSTAL IRON & STEEL WORKS», with a volume of 1800 m3 before (work with natural gas) and after major repairs (work with pulverized coal and with natural gas). Using the exergy method of analysis based on the results of calculating heat and power balances, a comparative analysis of changes in the energy efficiency and environmental indicators of BF No. 3 before and after its major repairs was carried out. It shown the expediency of integrated mastering of operating modes and modernization of the blast furnace for long-term and energy-efficient operation with pulverized coal. It disclosed the mechanism for improving the technical and economic indicators of work after major repairs by changing the heat and power conditions of the blast furnace. Its shown Improvement of exergy efficiency factor and environmental performance of BF No. 3 after major repairs.
Numerical Investigation of Simultaneous Injection of Pulverized Coal and Natural Gas with Oxygen Enrichment to the Blast Furnace.
