Furnace lining erosion is closely related to the operation stability and safety. The detection technology for hearth lining thickness of blast furnace was introduced.By using the data of thermocouples installed in the...Furnace lining erosion is closely related to the operation stability and safety. The detection technology for hearth lining thickness of blast furnace was introduced.By using the data of thermocouples installed in the bottom of furnace hearth,a mathematical model of erosion was established; the real state of the hearth and bottom erosion was studied; the erosion condition was followed,serving for the furnace longevity.展开更多
One of the methods forming the shell is to appropriately design the coolingstaves and hearth without overheating during the campaign life of the furnace. The three-dimensionalsteady mathematical models for calculating...One of the methods forming the shell is to appropriately design the coolingstaves and hearth without overheating during the campaign life of the furnace. The three-dimensionalsteady mathematical models for calculating the temperature distribution in the coolers andtwo-dimensional unsteady mathematical models with phase-change latent heat for calculating thetemperature distribution of the hearth bottom were established. The calculation results show thatthe formation of the slag-metal protection shell can be achieved by optimizing the design parametersof the coolers. Increasing the heat conductivity of the carbon brick can move the isothermal lineof 1150 deg C upward outside the hearth bottom.展开更多
Understanding the complex phenomena in BF hearth is essential to increase furnace productivity and to extend furnace campaign.We have developed several continuum-based mathematical/numerical models to simulate the mul...Understanding the complex phenomena in BF hearth is essential to increase furnace productivity and to extend furnace campaign.We have developed several continuum-based mathematical/numerical models to simulate the multi-phase flow,heat transfer and chemical reactions in the BF hearth.These models have generated an improved insight on the mechanisms for liquid drainage efficiency,lining erosion and wall protection in BF hearth under operational conditions.The current paper gives an overview of these studies in three aspects:Gas flow and pressure on the liquid surface,and their effect on the drainage characteristics;The flow and temperature distributions of liquid iron in BF hearth,and the temperature distribution in the refractories;Finally,titanium behaviors due to titania injection to form Ti(C,N) -rich scaffold on the hearth surface,to protect the hearth from erosion.展开更多
Due to the difficulty in measuring the burden trajectory directly in an actual blast furnace (BF), a mathematical model with Coriolis force and gas drag force considered was developed to predict it. The falling poin...Due to the difficulty in measuring the burden trajectory directly in an actual blast furnace (BF), a mathematical model with Coriolis force and gas drag force considered was developed to predict it. The falling point and width of the burden flow were obtained and analyzed by the model, the velocities of particles at the chute end were compared with and without the existence of Coriolis force, and the effects of chute length and chute torque on the falling point were also discussed. The simulation results are in good agreement with practical measurements with laser beams in a 2500 m3 BF.展开更多
The physical and mathematical model of temperature field for blast furnace stave coolers was established. The computation results show that the heat resistance of 2-6 mm water scale within the cooling pipe is about 7...The physical and mathematical model of temperature field for blast furnace stave coolers was established. The computation results show that the heat resistance of 2-6 mm water scale within the cooling pipe is about 7%-20% of the total heat resistance of cooling stave body, as for drilling duct type, the heat resistance of 2-6 mm water scale is about 88%-98% of the total heat resistance. Using drilling duct or full cast pipe can eliminate gas clearance and coating layer between pipes and cast iron body and reduce the heat resistance of the cooler sharply and improve the coefficient of heat transfer to a great extent. The water velocity within coolers can be kept at the 1evel of 0.5- 1 .5 m/s, the higher water velocity can not decrease the hot surface temperature, but can increase energy consumption for cooling water.展开更多
The molten liquid flow inside a packed bed is a familiar momentum transportation phenomenon in a blast furnace. With regard to the reported mathematical models describing the liquid flow within a packed bed, there are...The molten liquid flow inside a packed bed is a familiar momentum transportation phenomenon in a blast furnace. With regard to the reported mathematical models describing the liquid flow within a packed bed, there are some obstacles for their application in engineering design, or some limitations in the model itself. To overcome these problems, the forces from the packed bed to the liquid flow were divided into appropriate body and surface forces on the basis of three assumptions. Consequently, a new mathematical model was built to present the liquid flow inside the coke bed in a blast furnace. The mathematical model can predict the distribution of liquid flowrate and the liquid flowing range inside the packed bed at any time. The predicted results of this model accord well with the experimental data. The model will be applied considerably better in the simulation on the ironmaking process compared with the existent models.展开更多
A three-dimensional mathematical model of the combustion of pulverized coal and coke has been developed.The model is applied to the blowpipe-tuyere-raceway-coke bed region in an ironmaking blast furnace in one computa...A three-dimensional mathematical model of the combustion of pulverized coal and coke has been developed.The model is applied to the blowpipe-tuyere-raceway-coke bed region in an ironmaking blast furnace in one computational domain,which includes two parts:pulverized coal combustion model in the blowpipe-tuyere-raceway cavity and the coal/coke combustion model in the surrounding coke bed.The effects of coal properties are examined comprehensively,in terms of coal burnout and gas species distributions.The results indicate that using a coal of fine particle size or high VM content could improve burnout and would affect the gas composition considerably.The burnout is examined in two ways:compared with burnout along tuyere axis,burnout over the raceway surface is a more sensitive and sensible parameter to describe the amount of unburnt char entering the coke bed.The model is useful for examining the flow-thermo-chemical characteristics of the pulverized coal injection (PCI) process under various conditions in a blast furnace.展开更多
To diagnose the lining condition of the blast furnace hearth during its campaign, are widely used methods based on the analysis of the temperature characteristics of the refractory lining. Measurement of the temperatu...To diagnose the lining condition of the blast furnace hearth during its campaign, are widely used methods based on the analysis of the temperature characteristics of the refractory lining. Measurement of the temperature characteristics is performed by means of a few hundred thermocouples placed inside the refractory lining. The peculiarity of proposed and used mathematical models is a fully three-dimensional assessment of the refractory lining, presence mechanisms of adaptation to the actual thermal conductivity of refractories and optimization calculations to the work in the on-line mode. The new monitoring systems of the lining wear of the blast furnace hearth are established on 5 blast furnaces of integrated iron-and-steel works of China: No.4 by volume 3,200 m3 of “Jinan Iron & Steel Company” in Jinan (683 thermocouples), No.2 by volume 1,080 m3 of “Henan Jiyuan Iron & Steel (Group) Company” in Jiyuan (212 thermocouples), No.4 by volume 2,500 m3 of “Guangxi Liuzhou Iron & Steel (Group) Company” in Liuzhou (383 thermocouples), No.3 by volume 1,750 m3 of “Jinan Iron & Steel Company” in Jinan (524 thermocouples); No.1 by volume 1,750 m3 of “Jinan Iron & Steel Company” in Jinan (524 thermocouples).展开更多
A radiative heat transfer mathematical model for a one-dimensional long furnace was set up in a through-type roller-hearth furnace (TTRHF) in compact strip production (CSP). To accurately predict the heat exchange...A radiative heat transfer mathematical model for a one-dimensional long furnace was set up in a through-type roller-hearth furnace (TTRHF) in compact strip production (CSP). To accurately predict the heat exchange in the furnace, modeling of the complex gas energy-balance equation in volume zones was considered, and the heat transfer model of heating slabs and wall lines was coupled with the radiative heat transfer model to identify the surface zonal temperature. With numerical simulation, the temperature fields of gas, slabs, and wall lines in the furnace under one typical working condition were carefully accounted and analyzed. The fundamental theory for analyzing the thermal process in TI'RI-IF was provided.展开更多
Reducing coke use is an effective measure to reduce carbon emission and energy consumption in the blast furnace(BF)ironmaking.Essentially,BF is a high-temperature moving bed reactor,where complex physical transformati...Reducing coke use is an effective measure to reduce carbon emission and energy consumption in the blast furnace(BF)ironmaking.Essentially,BF is a high-temperature moving bed reactor,where complex physical transformations coupled with complicated reactions occur.This makes it challenging to investigate the factors determining BF performance with the conventional method.A multi-physical field coupling mathematical model of BF was thus developed to describe its mass and heat transfer as well as its intrinsic reactions.Then,the proposed model was validated with the production data.Under coupling conditions,influences of dominating reactions on BF performance(temperature distribution,gas distribution,iron formation reaction,and direct reduction degree)were revealed.The results indicated that coke combustion,indirect reduction,and direct reduction of iron ore mainly took place nearby the shaft tuyere,cohesive zone,and dripping zone,respectively.Besides,the rate of coke solution loss reaction was increased with the rising coke porosity in the cohesive zone.Considering the effect of coke porosity on the efficiency and stability of BF,the coke porosity of 0.42 was regarded as a reasonable value.展开更多
In this study,innovative ellipsoid pellet with craters on its surface was designed,and the direct reduction process was compared with ellipsoid(without craters)and sphere pellets.In addition,furnace temperature and un...In this study,innovative ellipsoid pellet with craters on its surface was designed,and the direct reduction process was compared with ellipsoid(without craters)and sphere pellets.In addition,furnace temperature and uneven heat flux density effects on the pellet direct reduction process were also studied.The results show that ellipsoid pellet is better than that of spherical pellet on metallization ratio.However,under the condition of non-uniform heat flow,the ellipsoid pellet final metallization rate and zinc removal rate were lower.Although the heat transfer effect of ellipsoid pellet with craters was not improved significantly,the metallization rate and zinc removal rate were found improved,which will have a cumulative effect on the pellets direct reduction process in rotary hearth furnace.Under varying furnace temperature conditions,the pellet temperature was higher than that of the constant furnace temperature.After 1200 s,pellet Fe concentration increased to 123.6%,metallization rate and zinc removal rate increased to 113.7%and 102.2%,respectively.These results can provide references for the carbon-containing pellet design used in rotary hearth furnace.展开更多
The burden distribution in the shaft of blast furnace is known to affect the gas distribution,heat transfer,and chemical reactions inside the furnace.However,the internal layer structure of burden in the shaft cannot ...The burden distribution in the shaft of blast furnace is known to affect the gas distribution,heat transfer,and chemical reactions inside the furnace.However,the internal layer structure of burden in the shaft cannot be directly measured.Hence,a mathematical model for evaluating burden profile and layer structure was established.A sensitivity analysis based on the model was implemented to elucidate the effect of some factors on the burden distribution,including the stockline height and the mass of central coke.The results show that the width of funnel zone widens with the increase in stockline height,and the mass percentage of ore to coke in this zone slightly increases.Besides,the mass of central coke shows a significant influence on the width of coke channel,and 2%of batch mass of coke is recommended to implement central coke charging operation.The model has been indirectly verified by the gas temperature in operating blast furnace and successfully applied to online evaluate burden distribution.展开更多
A hybrid dynamic model was proposed, which considered both the hydrokinetic and the chaotic properties of the blast furnace ironmaking process; and great emphasis was put on its mechanism. The new model took the high ...A hybrid dynamic model was proposed, which considered both the hydrokinetic and the chaotic properties of the blast furnace ironmaking process; and great emphasis was put on its mechanism. The new model took the high complexity of the blast furnace as well as the effects of main parameters of the model into account, and the predicted results were in very good agreement with actual data.展开更多
Direct reduction of dust composite pellets containing zinc and iron was examined by simulating the conditions of actual production process of a rotary hearth furnace (RHF) in laboratory. A mathematical model was con...Direct reduction of dust composite pellets containing zinc and iron was examined by simulating the conditions of actual production process of a rotary hearth furnace (RHF) in laboratory. A mathematical model was constructed to study the reduction kinetics of iron oxides and ZnO in the dust composite pellets. It was validated by comparing the calculated values with experimental results. The effects of furnace temperature, pellet radius, and pellet porosity on the reduction were investigated by the model. It is shown that furnace temperature has obvious influence on both of the reduction of iron oxides and ZnO, but the influence of pellet radius and porosity is much smaller. Model calculations suggest that both of the reduction of iron oxides and ZnO are under mixed control with interface reactions and Boudouard reaction in the early stage, but only with interface reactions in the later stage.展开更多
高炉料面形貌是反映煤气流分布和煤气利用率的关键指标,研究高炉料面炉料堆积形状数学建模方法对实现高炉精准布料控制和“双碳”战略在钢铁行业落地具有重要意义.针对高炉多环布料情况下料面堆积形状预测难的问题,本文提出了一种基于...高炉料面形貌是反映煤气流分布和煤气利用率的关键指标,研究高炉料面炉料堆积形状数学建模方法对实现高炉精准布料控制和“双碳”战略在钢铁行业落地具有重要意义.针对高炉多环布料情况下料面堆积形状预测难的问题,本文提出了一种基于炉料运动轨迹和径向移动距离的高炉料面炉料堆积形状建模方法.首先,提出了一种与炉料初始状态和溜槽状态相关的炉料运动轨迹建模方法,获取炉料从节流阀至料面的炉料运动轨迹,并确定炉料在炉喉空区的内轨迹曲线和外轨迹曲线.然后,基于炉料运动轨迹和初始料面形状,以体积守恒原则为约束,提出了一种基于炉料径向移动距离的高炉料面炉料堆积形状数学建模方法,获取炉料在料面的堆积形状.最后,基于某钢铁厂2#高炉的尺寸建立离散单元法(Discrete element method,DEM)仿真模型,模型仿真结果验证了所提方法的准确性和有效性.展开更多
文摘Furnace lining erosion is closely related to the operation stability and safety. The detection technology for hearth lining thickness of blast furnace was introduced.By using the data of thermocouples installed in the bottom of furnace hearth,a mathematical model of erosion was established; the real state of the hearth and bottom erosion was studied; the erosion condition was followed,serving for the furnace longevity.
基金The work was financially supported by"95"key project of China(No.1997-02-08).]
文摘One of the methods forming the shell is to appropriately design the coolingstaves and hearth without overheating during the campaign life of the furnace. The three-dimensionalsteady mathematical models for calculating the temperature distribution in the coolers andtwo-dimensional unsteady mathematical models with phase-change latent heat for calculating thetemperature distribution of the hearth bottom were established. The calculation results show thatthe formation of the slag-metal protection shell can be achieved by optimizing the design parametersof the coolers. Increasing the heat conductivity of the carbon brick can move the isothermal lineof 1150 deg C upward outside the hearth bottom.
文摘Understanding the complex phenomena in BF hearth is essential to increase furnace productivity and to extend furnace campaign.We have developed several continuum-based mathematical/numerical models to simulate the multi-phase flow,heat transfer and chemical reactions in the BF hearth.These models have generated an improved insight on the mechanisms for liquid drainage efficiency,lining erosion and wall protection in BF hearth under operational conditions.The current paper gives an overview of these studies in three aspects:Gas flow and pressure on the liquid surface,and their effect on the drainage characteristics;The flow and temperature distributions of liquid iron in BF hearth,and the temperature distribution in the refractories;Finally,titanium behaviors due to titania injection to form Ti(C,N) -rich scaffold on the hearth surface,to protect the hearth from erosion.
基金financially supported by the National Natural Science Foundation of China (No. 61271303)
文摘Due to the difficulty in measuring the burden trajectory directly in an actual blast furnace (BF), a mathematical model with Coriolis force and gas drag force considered was developed to predict it. The falling point and width of the burden flow were obtained and analyzed by the model, the velocities of particles at the chute end were compared with and without the existence of Coriolis force, and the effects of chute length and chute torque on the falling point were also discussed. The simulation results are in good agreement with practical measurements with laser beams in a 2500 m3 BF.
文摘The physical and mathematical model of temperature field for blast furnace stave coolers was established. The computation results show that the heat resistance of 2-6 mm water scale within the cooling pipe is about 7%-20% of the total heat resistance of cooling stave body, as for drilling duct type, the heat resistance of 2-6 mm water scale is about 88%-98% of the total heat resistance. Using drilling duct or full cast pipe can eliminate gas clearance and coating layer between pipes and cast iron body and reduce the heat resistance of the cooler sharply and improve the coefficient of heat transfer to a great extent. The water velocity within coolers can be kept at the 1evel of 0.5- 1 .5 m/s, the higher water velocity can not decrease the hot surface temperature, but can increase energy consumption for cooling water.
基金supported by the National Natural Science Foundation of China (No.50704040, 20805060)the Natural Science Foundation Project of Chongqing Science & Technology Commission, China (No.CSTC,2009BB4197)
文摘The molten liquid flow inside a packed bed is a familiar momentum transportation phenomenon in a blast furnace. With regard to the reported mathematical models describing the liquid flow within a packed bed, there are some obstacles for their application in engineering design, or some limitations in the model itself. To overcome these problems, the forces from the packed bed to the liquid flow were divided into appropriate body and surface forces on the basis of three assumptions. Consequently, a new mathematical model was built to present the liquid flow inside the coke bed in a blast furnace. The mathematical model can predict the distribution of liquid flowrate and the liquid flowing range inside the packed bed at any time. The predicted results of this model accord well with the experimental data. The model will be applied considerably better in the simulation on the ironmaking process compared with the existent models.
文摘A three-dimensional mathematical model of the combustion of pulverized coal and coke has been developed.The model is applied to the blowpipe-tuyere-raceway-coke bed region in an ironmaking blast furnace in one computational domain,which includes two parts:pulverized coal combustion model in the blowpipe-tuyere-raceway cavity and the coal/coke combustion model in the surrounding coke bed.The effects of coal properties are examined comprehensively,in terms of coal burnout and gas species distributions.The results indicate that using a coal of fine particle size or high VM content could improve burnout and would affect the gas composition considerably.The burnout is examined in two ways:compared with burnout along tuyere axis,burnout over the raceway surface is a more sensitive and sensible parameter to describe the amount of unburnt char entering the coke bed.The model is useful for examining the flow-thermo-chemical characteristics of the pulverized coal injection (PCI) process under various conditions in a blast furnace.
文摘To diagnose the lining condition of the blast furnace hearth during its campaign, are widely used methods based on the analysis of the temperature characteristics of the refractory lining. Measurement of the temperature characteristics is performed by means of a few hundred thermocouples placed inside the refractory lining. The peculiarity of proposed and used mathematical models is a fully three-dimensional assessment of the refractory lining, presence mechanisms of adaptation to the actual thermal conductivity of refractories and optimization calculations to the work in the on-line mode. The new monitoring systems of the lining wear of the blast furnace hearth are established on 5 blast furnaces of integrated iron-and-steel works of China: No.4 by volume 3,200 m3 of “Jinan Iron & Steel Company” in Jinan (683 thermocouples), No.2 by volume 1,080 m3 of “Henan Jiyuan Iron & Steel (Group) Company” in Jiyuan (212 thermocouples), No.4 by volume 2,500 m3 of “Guangxi Liuzhou Iron & Steel (Group) Company” in Liuzhou (383 thermocouples), No.3 by volume 1,750 m3 of “Jinan Iron & Steel Company” in Jinan (524 thermocouples); No.1 by volume 1,750 m3 of “Jinan Iron & Steel Company” in Jinan (524 thermocouples).
文摘A radiative heat transfer mathematical model for a one-dimensional long furnace was set up in a through-type roller-hearth furnace (TTRHF) in compact strip production (CSP). To accurately predict the heat exchange in the furnace, modeling of the complex gas energy-balance equation in volume zones was considered, and the heat transfer model of heating slabs and wall lines was coupled with the radiative heat transfer model to identify the surface zonal temperature. With numerical simulation, the temperature fields of gas, slabs, and wall lines in the furnace under one typical working condition were carefully accounted and analyzed. The fundamental theory for analyzing the thermal process in TI'RI-IF was provided.
基金supported by the National Natural Science Foundation of China(Grant Nos.22278001 and 21776002)the Natural Science Foundation of Anhui Provincial Education Department(No.KJ2021A0407)+1 种基金the Natural Science Foundation of Anhui Province(Grant No.2008085QB87)Anhui Provincial Postdoctoral Science Foundation(No.2021B538).
文摘Reducing coke use is an effective measure to reduce carbon emission and energy consumption in the blast furnace(BF)ironmaking.Essentially,BF is a high-temperature moving bed reactor,where complex physical transformations coupled with complicated reactions occur.This makes it challenging to investigate the factors determining BF performance with the conventional method.A multi-physical field coupling mathematical model of BF was thus developed to describe its mass and heat transfer as well as its intrinsic reactions.Then,the proposed model was validated with the production data.Under coupling conditions,influences of dominating reactions on BF performance(temperature distribution,gas distribution,iron formation reaction,and direct reduction degree)were revealed.The results indicated that coke combustion,indirect reduction,and direct reduction of iron ore mainly took place nearby the shaft tuyere,cohesive zone,and dripping zone,respectively.Besides,the rate of coke solution loss reaction was increased with the rising coke porosity in the cohesive zone.Considering the effect of coke porosity on the efficiency and stability of BF,the coke porosity of 0.42 was regarded as a reasonable value.
基金Project(cstc 2018 jszx-cyzdx 0100)supported by the Chongqing Technology Innovation and Application Demonstration Project,China。
文摘In this study,innovative ellipsoid pellet with craters on its surface was designed,and the direct reduction process was compared with ellipsoid(without craters)and sphere pellets.In addition,furnace temperature and uneven heat flux density effects on the pellet direct reduction process were also studied.The results show that ellipsoid pellet is better than that of spherical pellet on metallization ratio.However,under the condition of non-uniform heat flow,the ellipsoid pellet final metallization rate and zinc removal rate were lower.Although the heat transfer effect of ellipsoid pellet with craters was not improved significantly,the metallization rate and zinc removal rate were found improved,which will have a cumulative effect on the pellets direct reduction process in rotary hearth furnace.Under varying furnace temperature conditions,the pellet temperature was higher than that of the constant furnace temperature.After 1200 s,pellet Fe concentration increased to 123.6%,metallization rate and zinc removal rate increased to 113.7%and 102.2%,respectively.These results can provide references for the carbon-containing pellet design used in rotary hearth furnace.
基金The authors are grateful to the National Natural Science Foundation of China(U1960205)for the financial support of this work.
文摘The burden distribution in the shaft of blast furnace is known to affect the gas distribution,heat transfer,and chemical reactions inside the furnace.However,the internal layer structure of burden in the shaft cannot be directly measured.Hence,a mathematical model for evaluating burden profile and layer structure was established.A sensitivity analysis based on the model was implemented to elucidate the effect of some factors on the burden distribution,including the stockline height and the mass of central coke.The results show that the width of funnel zone widens with the increase in stockline height,and the mass percentage of ore to coke in this zone slightly increases.Besides,the mass of central coke shows a significant influence on the width of coke channel,and 2%of batch mass of coke is recommended to implement central coke charging operation.The model has been indirectly verified by the gas temperature in operating blast furnace and successfully applied to online evaluate burden distribution.
基金Item Sponsored by National Basic Research Programof China (2005EC000166) Ningbo Natural Science Foundation ofChina (2006A610032)
文摘A hybrid dynamic model was proposed, which considered both the hydrokinetic and the chaotic properties of the blast furnace ironmaking process; and great emphasis was put on its mechanism. The new model took the high complexity of the blast furnace as well as the effects of main parameters of the model into account, and the predicted results were in very good agreement with actual data.
基金financially supported by the National Basic Research Program of China (No. 2012CB720401)the National Key Technology Research and Development Program of China (No. 2011BAC01B02)
文摘Direct reduction of dust composite pellets containing zinc and iron was examined by simulating the conditions of actual production process of a rotary hearth furnace (RHF) in laboratory. A mathematical model was constructed to study the reduction kinetics of iron oxides and ZnO in the dust composite pellets. It was validated by comparing the calculated values with experimental results. The effects of furnace temperature, pellet radius, and pellet porosity on the reduction were investigated by the model. It is shown that furnace temperature has obvious influence on both of the reduction of iron oxides and ZnO, but the influence of pellet radius and porosity is much smaller. Model calculations suggest that both of the reduction of iron oxides and ZnO are under mixed control with interface reactions and Boudouard reaction in the early stage, but only with interface reactions in the later stage.
文摘高炉料面形貌是反映煤气流分布和煤气利用率的关键指标,研究高炉料面炉料堆积形状数学建模方法对实现高炉精准布料控制和“双碳”战略在钢铁行业落地具有重要意义.针对高炉多环布料情况下料面堆积形状预测难的问题,本文提出了一种基于炉料运动轨迹和径向移动距离的高炉料面炉料堆积形状建模方法.首先,提出了一种与炉料初始状态和溜槽状态相关的炉料运动轨迹建模方法,获取炉料从节流阀至料面的炉料运动轨迹,并确定炉料在炉喉空区的内轨迹曲线和外轨迹曲线.然后,基于炉料运动轨迹和初始料面形状,以体积守恒原则为约束,提出了一种基于炉料径向移动距离的高炉料面炉料堆积形状数学建模方法,获取炉料在料面的堆积形状.最后,基于某钢铁厂2#高炉的尺寸建立离散单元法(Discrete element method,DEM)仿真模型,模型仿真结果验证了所提方法的准确性和有效性.