It is of great importance to elucidate reduction swelling behaviors and reaction mechanism of oxidized pellet in hydrogen-enriched atmosphere under coke oven gas injection. In this work, the effects of hydrogen concen...It is of great importance to elucidate reduction swelling behaviors and reaction mechanism of oxidized pellet in hydrogen-enriched atmosphere under coke oven gas injection. In this work, the effects of hydrogen concentration in N_2-CO-H_2 atmosphere with unchanged CO content on reduction swelling behaviors of oxidized pellet at 1173 K were studied, to clarify the mechanism of hydrogen-enriched reduction and exclude the influences of CO. Then, the reduction swelling behaviors of oxidized pellet at 1173 K in actual atmosphere under coke oven gas(COG) injection, got from the simulation results of multi-fluid blast furnace model, were investigated. The results show that with the concentration of hydrogen increasing in N_2-CO-H_2 gas from 2% to 18%, the reduction swelling index of pellet decreases from 10.12% to 5.57% while the reduction ratio of pellet increases obviously from 39.85% to 69.58%. In addition, with COG injection rate increasing from 0 to 152.34 m^3/t, the reduction swelling index of pellet decreases slightly from 10.71% to 9.54% while the reduction ratio of pellet is increased from 31.57% to 36.39%. The microstructures of pellet are transformed from the platy structure to the flocculent structure.展开更多
Nowadays,there are two major trends,which are the increasing blast furnace （BF） working volume and the decreasing fuel resource as well as the decline in its quality,in the ironmaking filed. The two trends lead to t...Nowadays,there are two major trends,which are the increasing blast furnace （BF） working volume and the decreasing fuel resource as well as the decline in its quality,in the ironmaking filed. The two trends lead to the difficulty in the BF operation. The decline of the BF stability requires higher and more elaborate operational techniques. A reasonable and compatible BF comprehensive operating system,as the base of the BF stabilization,is desired to satisfy the demand of large-scaled BF developments. Based on the practical operation of Baosteel No. 3 BF in 2010, the present work analyzes and discusses the basic rules of large-scaled BF stable control techniques,and further optimizes and improves its gas flow control techniques, develops strategies against the decline in fuel quality, which will contribute to the promotion of largescaled BF operational techniques progress.展开更多
In recent years, the reformed coke oven gas (COG) was proposed to be used as reducing gas in a shaft furnace. A mathematical model of gas flow based on the reformed COG was built. The effects of the pressure ratio of ...In recent years, the reformed coke oven gas (COG) was proposed to be used as reducing gas in a shaft furnace. A mathematical model of gas flow based on the reformed COG was built. The effects of the pressure ratio of reducing gas to cooling gas (k) on the gas distribution in the shaft furnace were investigated. The calculation results show that k is an important operation parameter, which can obviously affect the gas distribution in the shaft furnace. The value of k should be compromised. Both too big and too small k values are not appropriate, and the most reasonable value for k is 1:1.33.Under this condition, the utilization coefficient of reducing gas, the utilization coefficient of cooling gas and the coefficient of upward gas are 0.94, 0.92 and 1.03, respectively. Based on the validation of physical experiments, the calculated values of the model agreed well with the physical experimental data. Thus, the established model can properly describe the reformed COG distribution in an actual shaft furnace.展开更多
基金Project(51404005)supported by the National Natural Science Foundation of China
文摘It is of great importance to elucidate reduction swelling behaviors and reaction mechanism of oxidized pellet in hydrogen-enriched atmosphere under coke oven gas injection. In this work, the effects of hydrogen concentration in N_2-CO-H_2 atmosphere with unchanged CO content on reduction swelling behaviors of oxidized pellet at 1173 K were studied, to clarify the mechanism of hydrogen-enriched reduction and exclude the influences of CO. Then, the reduction swelling behaviors of oxidized pellet at 1173 K in actual atmosphere under coke oven gas(COG) injection, got from the simulation results of multi-fluid blast furnace model, were investigated. The results show that with the concentration of hydrogen increasing in N_2-CO-H_2 gas from 2% to 18%, the reduction swelling index of pellet decreases from 10.12% to 5.57% while the reduction ratio of pellet increases obviously from 39.85% to 69.58%. In addition, with COG injection rate increasing from 0 to 152.34 m^3/t, the reduction swelling index of pellet decreases slightly from 10.71% to 9.54% while the reduction ratio of pellet is increased from 31.57% to 36.39%. The microstructures of pellet are transformed from the platy structure to the flocculent structure.
文摘Nowadays,there are two major trends,which are the increasing blast furnace （BF） working volume and the decreasing fuel resource as well as the decline in its quality,in the ironmaking filed. The two trends lead to the difficulty in the BF operation. The decline of the BF stability requires higher and more elaborate operational techniques. A reasonable and compatible BF comprehensive operating system,as the base of the BF stabilization,is desired to satisfy the demand of large-scaled BF developments. Based on the practical operation of Baosteel No. 3 BF in 2010, the present work analyzes and discusses the basic rules of large-scaled BF stable control techniques,and further optimizes and improves its gas flow control techniques, develops strategies against the decline in fuel quality, which will contribute to the promotion of largescaled BF operational techniques progress.
基金The financial supports of the National Natural Science Foundation of China(NSFC 51874080,NSFC 62001312,NSFC 51774071 and NSFC 51974073)Natural Science Foun-dation of Liaoning(2019-MS-132)are much appreciated.
文摘In recent years, the reformed coke oven gas (COG) was proposed to be used as reducing gas in a shaft furnace. A mathematical model of gas flow based on the reformed COG was built. The effects of the pressure ratio of reducing gas to cooling gas (k) on the gas distribution in the shaft furnace were investigated. The calculation results show that k is an important operation parameter, which can obviously affect the gas distribution in the shaft furnace. The value of k should be compromised. Both too big and too small k values are not appropriate, and the most reasonable value for k is 1:1.33.Under this condition, the utilization coefficient of reducing gas, the utilization coefficient of cooling gas and the coefficient of upward gas are 0.94, 0.92 and 1.03, respectively. Based on the validation of physical experiments, the calculated values of the model agreed well with the physical experimental data. Thus, the established model can properly describe the reformed COG distribution in an actual shaft furnace.
