The wetting behavior of slag–coke is a crucial factor influencing the permeability of the lower part of the blast furnace.However,a systematic understanding of the wetting behavior and underlying mechanisms between t...The wetting behavior of slag–coke is a crucial factor influencing the permeability of the lower part of the blast furnace.However,a systematic understanding of the wetting behavior and underlying mechanisms between titanium-containing slag and tuyere coke remains lacking.The sessile drop method was employed to explore the effects of temperature,binary basicity,FeO,and TiO_(2) contents on the wetting behavior of titanium-containing slag and tuyere coke.The results indicate that increasing the temperature enhances the adhesion and wettability of the droplet,reducing the contact angle.Meanwhile,it accelerates the chemical reactions between slag and coke,leading to faster equilibrium.Conversely,increasing slag basicity elevates the contact angle by inhibiting chemical reactions at the slag–coke interface.This inhibition reduces both contact area and depth,thereby hindering slag droplet spreading on the coke surface.The contact angle decreases as the FeO content in the slag increases.Notably,the increase in TiO_(2) content has a dual effect on slag–coke wettability.Initially,it promotes wetting by reducing surface tension and lowering the contact angle.While the TiO_(2) content exceeds 20 wt.%,Ti(C,N)forms a barrier layer at the slag–coke interface,hindering the contact between slag and coke and resulting in an increased contact angle.展开更多
Under the background of the strategic goal of"double carbon,"the carbon reduction and consumption reduction of the iron and steel industry,especially in the ironmaking process,need to be further improved.The...Under the background of the strategic goal of"double carbon,"the carbon reduction and consumption reduction of the iron and steel industry,especially in the ironmaking process,need to be further improved.The raceway of tuyere provides the chemical environment,fuel and power source for blast furnace smelting.The research on the characteristics of its action mode and mechanism is of great significance to clarify the way of reducing carbon and consumption of blast furnace.In general,the formation mechanism,energy distribution,research progress,extended resource injection and directional regulation are studied and expounded.The research results of various scholars on the characteristics of the raceway show that the raceway is a complex process including multiphase turbulent flow,heat,momentum,mass and homogeneous and heterogeneous chemical reactions.With the development of multi-source fuel injection technology,the complexity of problem research is more obvious.Therefore,the collection of multi-factor,multi-directional and multi-process characteristic information in the raceway can provide guarantee for the stability,smooth operation,high yield,carbon reduction and consumption reduction of blast furnace and provide new ideas for the green and low-carbon development of iron and steel industry.展开更多
To improve the high-temperature service properties of coppery tuyere,Co06 coating with a Ni60A interlayer was prepared on copper by plasma cladding.Ni60A interlayer acted as a bridge to promote the element diffusion,t...To improve the high-temperature service properties of coppery tuyere,Co06 coating with a Ni60A interlayer was prepared on copper by plasma cladding.Ni60A interlayer acted as a bridge to promote the element diffusion,thus achieving metallurgical bonding.Due to the strengthening effect ofγ-Co,Cr_(23)C_(6)and Cr_(7)C_(3)phases,the wear resistance of Co06–Ni60A coating was much higher than that of copper substrate.As the temperature increased,the wear resistance of coating decreased first and then increased.The coating exhibited better wear resistance at 600℃ due to the oxidation wear mechanism.Compared with copper substrate and Ni60A,the oxidation resistance of Co06 was increased by 6.0 and 1.9 times,respectively.For melting loss resistance,Co06–Ni60A coating was superior to Ni60A single-layer coating,but the molten iron can still form a micro-metallurgical bonding with the coating surface.展开更多
The phenomena of tuyere upward-warp have been found at No.6 blast furnace in Kunming Steel Company China after its blow-in, which has made a great impact on the practical production of the furnace. Thus, a number of e...The phenomena of tuyere upward-warp have been found at No.6 blast furnace in Kunming Steel Company China after its blow-in, which has made a great impact on the practical production of the furnace. Thus, a number of efforts have been made to elucidate the mechanism of this phenomenon. The results of investigation and tests revealed that the enrichment and expansion of zinc in the tuyere bricks is the main factor leading to the tuyere upward-warp. The eroding behavior of zinc is that the inner structure of the tuyere bricks turns from dense to loose with entering, enriching and expanding of zinc, which forms spot-like→stripe-like→ditch-like→vein-like→tumorlike eroding passage. Additionally, it is found that the sequence of deleterious ele- ments entering the tuyere refractory is K, Na, Zn and Pb, respectively. Finally, the phenomena and process of zinc crystallization and growth in the refractory have been clearly observed and recorded during this investigation.展开更多
A novel technology of tuyere protection is introduced. The ceramic coat .is synthesized by using in-situ combustion process as the internal, external, and nose protecting coat of BF tuyeres. It can effectively protect...A novel technology of tuyere protection is introduced. The ceramic coat .is synthesized by using in-situ combustion process as the internal, external, and nose protecting coat of BF tuyeres. It can effectively protect the tuyeres and reduce heat loss by cooling water. The technglogy is quick-acting, easy to use, energy-saving and can make tuyeres have long service life. The feasibility of the application of the tuyere ceramic coat is discussed and the energy-saving effect of the tuyere is compared with that of the tuyeres lined with refractory.展开更多
Tuyere coke probing was conducted at the Baosteel Corex Plant in order to gain a better understanding of the structure of the char bed in the melter gasifier （ MG ）. After screening, the specimens were observed by a...Tuyere coke probing was conducted at the Baosteel Corex Plant in order to gain a better understanding of the structure of the char bed in the melter gasifier （ MG ）. After screening, the specimens were observed by an optical microscope to determine the mechanism of the char bed formation. X-ray diffraction （XRD） was used to clarify the degree of graphitization and infer thermal history of coke. The results show that the amount of powder coming from lump coal in the burden is much more than that from coke. Based on this, measures for improving the char bed＇ s permeability are proposed.展开更多
This article presents in detail the assembling and welding process technique of the steel box girder tuyere blocks of Taizhou Bridge. The application of this process technique effectively solves the problem of welding...This article presents in detail the assembling and welding process technique of the steel box girder tuyere blocks of Taizhou Bridge. The application of this process technique effectively solves the problem of welding stress release in tuyere block assembling and welding without increasing the number of turns of the blocks and overhead welding, thus avoiding possible structural deformation due to excessive accumulation of internal welding stress, greatly reducing the repeated deformation and correction work during assembling and welding, and ensuring the weld seam quality and overall dimensions of tuvere blocks of Taizhou Bridze.展开更多
A SiC assembled large block for blast furnace tuyeres was prepared using silicon carbide particles(3-1 and 1-0.088 mm)and fine powder(<0.088 mm),silicon powder(<0.088 mm),industrial carbon black(N990),microsili...A SiC assembled large block for blast furnace tuyeres was prepared using silicon carbide particles(3-1 and 1-0.088 mm)and fine powder(<0.088 mm),silicon powder(<0.088 mm),industrial carbon black(N990),microsilica,ρ-Al_(2)O_(3) powder,etc.as raw materials.The developed block was compared with a silicon nitride bonded silicon carbide brick,a self-bonded silicon carbide brick and an imported self-bonded silicon carbide block to analyze and evaluate their service performance.The results show that:(1)in the 0-100 mm zone,the SiC large block mainly consists ofβ-SiC and nitrides such as O'-SiAlON,β-SiAlON,α-Si_(3)N_(4),and Si_(2)N_(2)O,the bulk density is 2.68-2.70 g·cm^(-3),the apparent porosity is 14%-15%,and the material structure is uniform;(2)in the 0-100 mm zone,β-SiC nano-whiskers intercalate with nitrides;with the depth increasing,the number of flocculentβ-SiC nano-whiskers increases,while the number of nitrides decreases;when the depth reaches 150 mm or more,the main bonding phases areβ-SiC and mullite;(3)compared with the reference products,the developed SiC large block has a good basic performance,and after alkali corrosion,the mass change rate is-0.1%,which is obviously superior to the imported self-bonded silicon carbide and the homemade silicon nitride bonded silicon carbide materials.展开更多
The aim of this study is to investigate the influence of the angle of the pulverized coal (PC) injection lance on the combustion characteristics of fuel in the raceway of blast furnace tuyeres. Using FLUENT software, ...The aim of this study is to investigate the influence of the angle of the pulverized coal (PC) injection lance on the combustion characteristics of fuel in the raceway of blast furnace tuyeres. Using FLUENT software, a Euler-Lagrange three-dimensional numerical model was constructed to analyze the influence of different positions of blast furnace tuyere coal powder injection lance (coaxial and cross-axis) on key parameters such as temperature distribution, gas flow, and combustion efficiency. The results demonstrate that adjusting the angle of the injection lance significantly modifies the average and peak temperatures in the raceway, while the composition of gas components remains relatively stable. When the injection lance angle is 10°, the average temperature and peak temperature in the raceway are 2294 K and 2747 K, respectively. When the injection lance angle is 12°, the combustion efficiency of the PC reaches 80.8%. This study reveals the significant impact of the injection lance angle on the combustion process. Especially at an angle of 12°, the combustion efficiency of the blast furnace significantly improves. With coaxial injection, the combustion rate increases as the distance between the injection lance tip and the tuyere increases. This paper is instructive for the optimization of the blast furnace combustion system, which improve fuel utilization efficiency and reduce environmental emissions. This paper provides practical recommendations for adjusting blast furnace operational parameters, offering insights for achieving more efficient and environmentally friendly industrial production.展开更多
The energy consumption of heating,ventilation,and air conditioning(HVAC)systems holds a significant position in building energy usage,accounting for about 65%of the total energy consumption.Moreover,with the advanceme...The energy consumption of heating,ventilation,and air conditioning(HVAC)systems holds a significant position in building energy usage,accounting for about 65%of the total energy consumption.Moreover,with the advancement of building automation,the energy consumption of ventilation systems continues to grow.This study focuses on improving the performance of spherical tuyeres in HVAC systems.It primarily utilizes neural networks and multi-island genetic algorithms(MIGA)for multi-parameter optimization.By employing methods such as structural parameterization,accurate and fast computational fluid dynamics(CFD)simulations,a minimized sample space,and a rational optimization strategy,the time cycle of the optimization process is shortened.Additionally,a new comprehensive evaluation index is proposed in this research to describe the performance of spherical tuyeres,which can be used to more accurately assess spherical tuyeres with different structures.The results show that by establishing a neural network prediction model and combining it with the multi-island genetic algorithm,a novel spherical tuyere design was successfully achieved.The optimized novel spherical tuyeres achieved a 27.05%reduction in the spherical tuyeres effective index(STEI)compared to the traditional spherical tuyeres.Moreover,the resistance decreased by 15.68%,and the jet length increased by 7.57%.The experimental results demonstrate that our proposed optimization method exhibits high accuracy,good generalization capability,and excellent agreement at different Reynolds numbers.展开更多
The injection of hydrogen-rich fuel into the blast furnace tuyere is highly significant for reducing carbon dioxide(CO_(2))emissions.However,the hydrogen-rich fuel injection can lead to insufficient kinetic energy of ...The injection of hydrogen-rich fuel into the blast furnace tuyere is highly significant for reducing carbon dioxide(CO_(2))emissions.However,the hydrogen-rich fuel injection can lead to insufficient kinetic energy of the blast and reduce pulverized coal combustion rate.To solve these problems,a method of coherent jet of hydrogen-rich fuel was developed,and the combustion process of the hydrogen-rich fuel and pulverized coal was simulated by coupling computational fluid dynamics and discrete phase method(CFD-DPM)in blast furnace tuyere.The effects of hydrogen content on the distributions of gas velocity,temperature,and species in the reaction region were systematically analyzed.Results indicate that high-temperature and low-density flame can be generated around the tuyere through hydrogen-rich fuel,which effectively restrain the attenuation of blast energy.Meanwhile,the coherent flame heats the hot gas and pulverized coal at the outlet of the tuyere,which is conducive to enhance the temperature of the reaction region and the burning rate of pulverized coal.The increase in hydrogen content within the hydrogen-rich fuel leads to a gradual contraction of the CO_(2) high concentration region at the center of the reaction region,while simultaneously expanding the high concentration region of water vapor(H_(2)O).展开更多
The interaction mechanism between the combustion products of pulverized coal injected and coke in the raceway of blast furnace was studied through thermodynamic calculation and experiments.The results indicated that a...The interaction mechanism between the combustion products of pulverized coal injected and coke in the raceway of blast furnace was studied through thermodynamic calculation and experiments.The results indicated that additives significantly affected the melting property of coal ash in high temperature zone.Although the unburnt char,raw coal ash,and catalyzed coal ash failed to wet the coke surface,the wettability of the catalyzed coal ash on the coke was greater than that of the raw coal ash.Since the unburnt char had weak reaction with the coke surface,it showed little influence on the surface morphology of the coke.The interaction between the raw coal ash and the coke gave rise to the increase in the pore size on the coke surface.However,the raw coal ash only affected the coke surface and the entrances of the pores owing to its poor fluidity.After being melted,the catalyzed coal ash was expected to immerge into the inside part of the coke and then react with the coke,resulting in an expansion and increase of coke cavities.The raw coal ash and the unburnt char reduced the coke reactivity,while the catalyzed coal ash improved the coke reactivity.Thereinto,the coal ash containing Fe2O3 exhibited a larger influence on the reactivity than that containing CaO.展开更多
The change of bubbles and the position of the tuyere in an oxygen coal combustion melting and separating furnace affect the flow and splash behavior of the molten pool.To analyze this problem further,a three-dimension...The change of bubbles and the position of the tuyere in an oxygen coal combustion melting and separating furnace affect the flow and splash behavior of the molten pool.To analyze this problem further,a three-dimensional numerical simulation method was used to explore the behavior and change of the flow field inside the molten pool during double-row tuyere injection.In addition,the arrangement of the tuyere was changed for a more detailed understanding of the internal phase distribution and splashing in a molten pool.The results indicated that under three-dimensional numerical simulation conditions,bubbles rise after leaving the tuyere and break on the surface of the molten pool,which results in certain fluctuations in the nearby melt.During the injection process of the tuyere,the meteorological accumulation in the middle part of the molten pool formed part of the foam slag because of the influence of surface tension.When the layout of the upper and lower exhaust tuyeres was changed from staggered to symmetrical,or when the spacing of the upper and lower exhaust tuyeres changed,it had an effect on the phase distribution and splash behavior.展开更多
The production indexes were deteriorated due to quality coke,Utilization Factor 2.0 t/m^3·d,PCI 100 kg/T,According to Analysis the Mechanism of Production of low hot strength coke quality on Blast Furnace Smooth,...The production indexes were deteriorated due to quality coke,Utilization Factor 2.0 t/m^3·d,PCI 100 kg/T,According to Analysis the Mechanism of Production of low hot strength coke quality on Blast Furnace Smooth,The coke cold strength retained M_(10)<6.3 over a long period of time in order to insure coke granularity and permeability index in cohesive zone;A_(ad)<12 and granularity tranquilization is useful BF production.The PCI protect coke hot strength by high rate bituminous coals;high rate H_2 in BF gas bate coke demolish.blast furnace operation,on monitoring and operation BF,tranquilization the BLAST FURNACE temperature,PT controls parameter area is about 1500℃;strengthen management of permeability index,improve Top-pressure for Blast Furnace,Strengthening the Management of the Raw Materials and Fuel,logical rate of sinter Level off about 70%to improve Metallurgical Properties of Burdens.Parameters of wind have been adopted About 10000-11000 kg·m/s;,theoretical flame temperature in a blast furnace have been adjusted area is about 2050-2200℃;the temperature direction about copper stave management established act;according to this measures,According to Improvement Center Gas Flow Instability in the first place,the gas flow distribution turns to the reasonable state.Strengthen furnace casthouse operation ect,Utilization Factor improve 2.2 t/m^3·d,PCI 130 kg/T.Cold and hot state strength indexes of coke on BF production were instability.According to optimize the Operating Paramete in specifically economy technology indexes conduction,the BF condiction can keeping steady and smooth.展开更多
This article shows an innovative method to model and validate the hot air flow through the blast furnacés tuyeres. This study will be the basis for flow measurements implementation and safety interlocks for the p...This article shows an innovative method to model and validate the hot air flow through the blast furnacés tuyeres. This study will be the basis for flow measurements implementation and safety interlocks for the pulverized coal injection. The flow measurements were taken in the blast furnace down leg pipes by installing refractory Venturi tubes. The system for the calculation of differential pressure takes into consideration the dimension of the Venturi, the air density and compressibility. The objective is to specify the flow transmitters required to automate a control system and implement safety interlocks for the coal injection plant.展开更多
The zinc vapor condenses on the top of the blast furnace and adheres to the furnace wall, causing the furnace wall to thicken and nodulate, which affects the smooth operation of the furnace. It can block up the gas up...The zinc vapor condenses on the top of the blast furnace and adheres to the furnace wall, causing the furnace wall to thicken and nodulate, which affects the smooth operation of the furnace. It can block up the gas up pipe and down pipe, damage the body of the blast furnace and reduce the service life of the first generation of the blast furnace. The small sleeve of tuyere is bonded to prolong the treatment time of air rest, and the middle sleeve of tuyere is deformed to cause air leakage, which brings hidden danger to production. Zinc rich liquid drops on tuyere and burns cooling equipment, which is not conducive to high production, low consumption and long life of blast furnace.展开更多
基金supported by the Postdoctor Project of Hubei Province(2024HBBHCXA074)National Natural Science Foundation of China(51974212)+2 种基金China Baowu Low Carbon Metallurgy Innovation Foundation(BWLCF202116)Foundation of Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking(NPISlab25-03)Science and Technology Major Project of Wuhan(2023020302020572).
文摘The wetting behavior of slag–coke is a crucial factor influencing the permeability of the lower part of the blast furnace.However,a systematic understanding of the wetting behavior and underlying mechanisms between titanium-containing slag and tuyere coke remains lacking.The sessile drop method was employed to explore the effects of temperature,binary basicity,FeO,and TiO_(2) contents on the wetting behavior of titanium-containing slag and tuyere coke.The results indicate that increasing the temperature enhances the adhesion and wettability of the droplet,reducing the contact angle.Meanwhile,it accelerates the chemical reactions between slag and coke,leading to faster equilibrium.Conversely,increasing slag basicity elevates the contact angle by inhibiting chemical reactions at the slag–coke interface.This inhibition reduces both contact area and depth,thereby hindering slag droplet spreading on the coke surface.The contact angle decreases as the FeO content in the slag increases.Notably,the increase in TiO_(2) content has a dual effect on slag–coke wettability.Initially,it promotes wetting by reducing surface tension and lowering the contact angle.While the TiO_(2) content exceeds 20 wt.%,Ti(C,N)forms a barrier layer at the slag–coke interface,hindering the contact between slag and coke and resulting in an increased contact angle.
基金financially supported by the Major Science and Technology-Special Plan“Unveiling and Leading”Project of Shanxi Province(No.202201050201011)National Natural Science Foundation of China(No.52274316)+4 种基金China Baowu Low-Carbon Metallurgy Innovation Foundation(No.BWLCF202116)National Key R&D Program of China(No.2022YFE0208100)Major Science and Technology Project of Xinjiang(No.2022A01003)Major Science and Technology Projects of Anhui Province(No.202210700037)Special Funding for Science and Technology of China Minmetals Corporation(No.2021ZXD01).
文摘Under the background of the strategic goal of"double carbon,"the carbon reduction and consumption reduction of the iron and steel industry,especially in the ironmaking process,need to be further improved.The raceway of tuyere provides the chemical environment,fuel and power source for blast furnace smelting.The research on the characteristics of its action mode and mechanism is of great significance to clarify the way of reducing carbon and consumption of blast furnace.In general,the formation mechanism,energy distribution,research progress,extended resource injection and directional regulation are studied and expounded.The research results of various scholars on the characteristics of the raceway show that the raceway is a complex process including multiphase turbulent flow,heat,momentum,mass and homogeneous and heterogeneous chemical reactions.With the development of multi-source fuel injection technology,the complexity of problem research is more obvious.Therefore,the collection of multi-factor,multi-directional and multi-process characteristic information in the raceway can provide guarantee for the stability,smooth operation,high yield,carbon reduction and consumption reduction of blast furnace and provide new ideas for the green and low-carbon development of iron and steel industry.
基金supported by the University Synergy Innovation Program of Anhui Province(Grant Nos.GXXT-2023-025 and GXXT-2023-026)Natural Science Foundation of Anhui Province(Grant Nos.2008085ME149,2308085QE132 and 2308065ME171)Anhui University Scientific Research Project(Grant Nos.2022AH040247,2023AH051660,2023AH051670 and 2023AH051671).
文摘To improve the high-temperature service properties of coppery tuyere,Co06 coating with a Ni60A interlayer was prepared on copper by plasma cladding.Ni60A interlayer acted as a bridge to promote the element diffusion,thus achieving metallurgical bonding.Due to the strengthening effect ofγ-Co,Cr_(23)C_(6)and Cr_(7)C_(3)phases,the wear resistance of Co06–Ni60A coating was much higher than that of copper substrate.As the temperature increased,the wear resistance of coating decreased first and then increased.The coating exhibited better wear resistance at 600℃ due to the oxidation wear mechanism.Compared with copper substrate and Ni60A,the oxidation resistance of Co06 was increased by 6.0 and 1.9 times,respectively.For melting loss resistance,Co06–Ni60A coating was superior to Ni60A single-layer coating,but the molten iron can still form a micro-metallurgical bonding with the coating surface.
基金supported by Program for New Century Excellent Talents in University(NCET-2008-0099)
文摘The phenomena of tuyere upward-warp have been found at No.6 blast furnace in Kunming Steel Company China after its blow-in, which has made a great impact on the practical production of the furnace. Thus, a number of efforts have been made to elucidate the mechanism of this phenomenon. The results of investigation and tests revealed that the enrichment and expansion of zinc in the tuyere bricks is the main factor leading to the tuyere upward-warp. The eroding behavior of zinc is that the inner structure of the tuyere bricks turns from dense to loose with entering, enriching and expanding of zinc, which forms spot-like→stripe-like→ditch-like→vein-like→tumorlike eroding passage. Additionally, it is found that the sequence of deleterious ele- ments entering the tuyere refractory is K, Na, Zn and Pb, respectively. Finally, the phenomena and process of zinc crystallization and growth in the refractory have been clearly observed and recorded during this investigation.
基金Item Sponsored by National Natural Science Foundation of China (50572005 ,50172006)
文摘A novel technology of tuyere protection is introduced. The ceramic coat .is synthesized by using in-situ combustion process as the internal, external, and nose protecting coat of BF tuyeres. It can effectively protect the tuyeres and reduce heat loss by cooling water. The technglogy is quick-acting, easy to use, energy-saving and can make tuyeres have long service life. The feasibility of the application of the tuyere ceramic coat is discussed and the energy-saving effect of the tuyere is compared with that of the tuyeres lined with refractory.
文摘Tuyere coke probing was conducted at the Baosteel Corex Plant in order to gain a better understanding of the structure of the char bed in the melter gasifier （ MG ）. After screening, the specimens were observed by an optical microscope to determine the mechanism of the char bed formation. X-ray diffraction （XRD） was used to clarify the degree of graphitization and infer thermal history of coke. The results show that the amount of powder coming from lump coal in the burden is much more than that from coke. Based on this, measures for improving the char bed＇ s permeability are proposed.
文摘This article presents in detail the assembling and welding process technique of the steel box girder tuyere blocks of Taizhou Bridge. The application of this process technique effectively solves the problem of welding stress release in tuyere block assembling and welding without increasing the number of turns of the blocks and overhead welding, thus avoiding possible structural deformation due to excessive accumulation of internal welding stress, greatly reducing the repeated deformation and correction work during assembling and welding, and ensuring the weld seam quality and overall dimensions of tuvere blocks of Taizhou Bridze.
文摘A SiC assembled large block for blast furnace tuyeres was prepared using silicon carbide particles(3-1 and 1-0.088 mm)and fine powder(<0.088 mm),silicon powder(<0.088 mm),industrial carbon black(N990),microsilica,ρ-Al_(2)O_(3) powder,etc.as raw materials.The developed block was compared with a silicon nitride bonded silicon carbide brick,a self-bonded silicon carbide brick and an imported self-bonded silicon carbide block to analyze and evaluate their service performance.The results show that:(1)in the 0-100 mm zone,the SiC large block mainly consists ofβ-SiC and nitrides such as O'-SiAlON,β-SiAlON,α-Si_(3)N_(4),and Si_(2)N_(2)O,the bulk density is 2.68-2.70 g·cm^(-3),the apparent porosity is 14%-15%,and the material structure is uniform;(2)in the 0-100 mm zone,β-SiC nano-whiskers intercalate with nitrides;with the depth increasing,the number of flocculentβ-SiC nano-whiskers increases,while the number of nitrides decreases;when the depth reaches 150 mm or more,the main bonding phases areβ-SiC and mullite;(3)compared with the reference products,the developed SiC large block has a good basic performance,and after alkali corrosion,the mass change rate is-0.1%,which is obviously superior to the imported self-bonded silicon carbide and the homemade silicon nitride bonded silicon carbide materials.
基金support of this research on the mechanism of enhancing the performance of composite pellets_made from limonite(Project No.KKS0202152010,202101AT070083)National Natural Science Foundation of China(No.52104351)+1 种基金the Yunnan Fundamental Research Projects(No.202301AT070795,202101AU070088)the author Lei Gao would like to acknowledge Yunnan Province Xingdian Talent Support Plan Project.
文摘The aim of this study is to investigate the influence of the angle of the pulverized coal (PC) injection lance on the combustion characteristics of fuel in the raceway of blast furnace tuyeres. Using FLUENT software, a Euler-Lagrange three-dimensional numerical model was constructed to analyze the influence of different positions of blast furnace tuyere coal powder injection lance (coaxial and cross-axis) on key parameters such as temperature distribution, gas flow, and combustion efficiency. The results demonstrate that adjusting the angle of the injection lance significantly modifies the average and peak temperatures in the raceway, while the composition of gas components remains relatively stable. When the injection lance angle is 10°, the average temperature and peak temperature in the raceway are 2294 K and 2747 K, respectively. When the injection lance angle is 12°, the combustion efficiency of the PC reaches 80.8%. This study reveals the significant impact of the injection lance angle on the combustion process. Especially at an angle of 12°, the combustion efficiency of the blast furnace significantly improves. With coaxial injection, the combustion rate increases as the distance between the injection lance tip and the tuyere increases. This paper is instructive for the optimization of the blast furnace combustion system, which improve fuel utilization efficiency and reduce environmental emissions. This paper provides practical recommendations for adjusting blast furnace operational parameters, offering insights for achieving more efficient and environmentally friendly industrial production.
基金This research project was sponsored by the National Natural Science Foundation of China General Program(No.52178090 and No.51878533)the Science and Technology New Star Project of Shaanxi Province(No.2020KJXX-013).
文摘The energy consumption of heating,ventilation,and air conditioning(HVAC)systems holds a significant position in building energy usage,accounting for about 65%of the total energy consumption.Moreover,with the advancement of building automation,the energy consumption of ventilation systems continues to grow.This study focuses on improving the performance of spherical tuyeres in HVAC systems.It primarily utilizes neural networks and multi-island genetic algorithms(MIGA)for multi-parameter optimization.By employing methods such as structural parameterization,accurate and fast computational fluid dynamics(CFD)simulations,a minimized sample space,and a rational optimization strategy,the time cycle of the optimization process is shortened.Additionally,a new comprehensive evaluation index is proposed in this research to describe the performance of spherical tuyeres,which can be used to more accurately assess spherical tuyeres with different structures.The results show that by establishing a neural network prediction model and combining it with the multi-island genetic algorithm,a novel spherical tuyere design was successfully achieved.The optimized novel spherical tuyeres achieved a 27.05%reduction in the spherical tuyeres effective index(STEI)compared to the traditional spherical tuyeres.Moreover,the resistance decreased by 15.68%,and the jet length increased by 7.57%.The experimental results demonstrate that our proposed optimization method exhibits high accuracy,good generalization capability,and excellent agreement at different Reynolds numbers.
基金the National Natural Science Foundation of China(Grant Nos.51874171,52074150,and 51974154)for the financial support of current work.
文摘The injection of hydrogen-rich fuel into the blast furnace tuyere is highly significant for reducing carbon dioxide(CO_(2))emissions.However,the hydrogen-rich fuel injection can lead to insufficient kinetic energy of the blast and reduce pulverized coal combustion rate.To solve these problems,a method of coherent jet of hydrogen-rich fuel was developed,and the combustion process of the hydrogen-rich fuel and pulverized coal was simulated by coupling computational fluid dynamics and discrete phase method(CFD-DPM)in blast furnace tuyere.The effects of hydrogen content on the distributions of gas velocity,temperature,and species in the reaction region were systematically analyzed.Results indicate that high-temperature and low-density flame can be generated around the tuyere through hydrogen-rich fuel,which effectively restrain the attenuation of blast energy.Meanwhile,the coherent flame heats the hot gas and pulverized coal at the outlet of the tuyere,which is conducive to enhance the temperature of the reaction region and the burning rate of pulverized coal.The increase in hydrogen content within the hydrogen-rich fuel leads to a gradual contraction of the CO_(2) high concentration region at the center of the reaction region,while simultaneously expanding the high concentration region of water vapor(H_(2)O).
基金financially supported by the National Natural Science Foundation of China (No.51374166, 51574189)the Natural Science Foundation Research Project of Shaanxi,China(No.2016JQ5041)the Shaanxi Province Department of Education Fund, China(No.16JK1450)
文摘The interaction mechanism between the combustion products of pulverized coal injected and coke in the raceway of blast furnace was studied through thermodynamic calculation and experiments.The results indicated that additives significantly affected the melting property of coal ash in high temperature zone.Although the unburnt char,raw coal ash,and catalyzed coal ash failed to wet the coke surface,the wettability of the catalyzed coal ash on the coke was greater than that of the raw coal ash.Since the unburnt char had weak reaction with the coke surface,it showed little influence on the surface morphology of the coke.The interaction between the raw coal ash and the coke gave rise to the increase in the pore size on the coke surface.However,the raw coal ash only affected the coke surface and the entrances of the pores owing to its poor fluidity.After being melted,the catalyzed coal ash was expected to immerge into the inside part of the coke and then react with the coke,resulting in an expansion and increase of coke cavities.The raw coal ash and the unburnt char reduced the coke reactivity,while the catalyzed coal ash improved the coke reactivity.Thereinto,the coal ash containing Fe2O3 exhibited a larger influence on the reactivity than that containing CaO.
基金supported by the National Key R&D Program of China(2017YFB0603800 and 2017YFB0603802).
文摘The change of bubbles and the position of the tuyere in an oxygen coal combustion melting and separating furnace affect the flow and splash behavior of the molten pool.To analyze this problem further,a three-dimensional numerical simulation method was used to explore the behavior and change of the flow field inside the molten pool during double-row tuyere injection.In addition,the arrangement of the tuyere was changed for a more detailed understanding of the internal phase distribution and splashing in a molten pool.The results indicated that under three-dimensional numerical simulation conditions,bubbles rise after leaving the tuyere and break on the surface of the molten pool,which results in certain fluctuations in the nearby melt.During the injection process of the tuyere,the meteorological accumulation in the middle part of the molten pool formed part of the foam slag because of the influence of surface tension.When the layout of the upper and lower exhaust tuyeres was changed from staggered to symmetrical,or when the spacing of the upper and lower exhaust tuyeres changed,it had an effect on the phase distribution and splash behavior.
文摘The production indexes were deteriorated due to quality coke,Utilization Factor 2.0 t/m^3·d,PCI 100 kg/T,According to Analysis the Mechanism of Production of low hot strength coke quality on Blast Furnace Smooth,The coke cold strength retained M_(10)<6.3 over a long period of time in order to insure coke granularity and permeability index in cohesive zone;A_(ad)<12 and granularity tranquilization is useful BF production.The PCI protect coke hot strength by high rate bituminous coals;high rate H_2 in BF gas bate coke demolish.blast furnace operation,on monitoring and operation BF,tranquilization the BLAST FURNACE temperature,PT controls parameter area is about 1500℃;strengthen management of permeability index,improve Top-pressure for Blast Furnace,Strengthening the Management of the Raw Materials and Fuel,logical rate of sinter Level off about 70%to improve Metallurgical Properties of Burdens.Parameters of wind have been adopted About 10000-11000 kg·m/s;,theoretical flame temperature in a blast furnace have been adjusted area is about 2050-2200℃;the temperature direction about copper stave management established act;according to this measures,According to Improvement Center Gas Flow Instability in the first place,the gas flow distribution turns to the reasonable state.Strengthen furnace casthouse operation ect,Utilization Factor improve 2.2 t/m^3·d,PCI 130 kg/T.Cold and hot state strength indexes of coke on BF production were instability.According to optimize the Operating Paramete in specifically economy technology indexes conduction,the BF condiction can keeping steady and smooth.
文摘This article shows an innovative method to model and validate the hot air flow through the blast furnacés tuyeres. This study will be the basis for flow measurements implementation and safety interlocks for the pulverized coal injection. The flow measurements were taken in the blast furnace down leg pipes by installing refractory Venturi tubes. The system for the calculation of differential pressure takes into consideration the dimension of the Venturi, the air density and compressibility. The objective is to specify the flow transmitters required to automate a control system and implement safety interlocks for the coal injection plant.
文摘The zinc vapor condenses on the top of the blast furnace and adheres to the furnace wall, causing the furnace wall to thicken and nodulate, which affects the smooth operation of the furnace. It can block up the gas up pipe and down pipe, damage the body of the blast furnace and reduce the service life of the first generation of the blast furnace. The small sleeve of tuyere is bonded to prolong the treatment time of air rest, and the middle sleeve of tuyere is deformed to cause air leakage, which brings hidden danger to production. Zinc rich liquid drops on tuyere and burns cooling equipment, which is not conducive to high production, low consumption and long life of blast furnace.
