Based on the principle of RH process and the mechanism of decarburization, a three-dimensional mathematical model to represent the flow and decarburization of molten steel was established. The model was verified and t...Based on the principle of RH process and the mechanism of decarburization, a three-dimensional mathematical model to represent the flow and decarburization of molten steel was established. The model was verified and the effect of operating parameters on the process was investigated.展开更多
An improved mathematical model to describe the decarburization process in basic oxygen furnaces for steelmaking is presented in this work. This model takes into account those factors or parameters that determine the b...An improved mathematical model to describe the decarburization process in basic oxygen furnaces for steelmaking is presented in this work. This model takes into account those factors or parameters that determine the bath-oxygen impact area, such as the cavity depth, the lance height, the number of nozzles and the nozzles diameter. In the thermal issue, the model includes the targeted carbon content and temperature. The model is numerically solved, and is validated using reported data plant. The oxygen flow rate and the lance height are varied in the numerical simulations to study their effect on the carbon content and decarburization rate.展开更多
用顶吹 CO2 - Na OH溶液体系模拟了 RH- KTB顶吹氧溶氧过程。通过对碱液吸收 CO2 反应动力学的研究 ,考察了操作参数对 RH- KTB顶吹氧脱碳过程中溶氧反应的影响。结果表明 :提高气相中氧分压、增加提升氩气流量或采用低枪位喷吹都有利...用顶吹 CO2 - Na OH溶液体系模拟了 RH- KTB顶吹氧溶氧过程。通过对碱液吸收 CO2 反应动力学的研究 ,考察了操作参数对 RH- KTB顶吹氧脱碳过程中溶氧反应的影响。结果表明 :提高气相中氧分压、增加提升氩气流量或采用低枪位喷吹都有利于加速溶氧脱碳。实验中还发现 :顶吹氧气流量对容积传质系数影响很小 。展开更多
A mathematic model has been presented to predict the decarburization kinetics of grain-oriented silicon steel sheet in the gas mixture of N2–H2–H2O during annealing.This model is based on the carbon flux balance bet...A mathematic model has been presented to predict the decarburization kinetics of grain-oriented silicon steel sheet in the gas mixture of N2–H2–H2O during annealing.This model is based on the carbon flux balance between the oxidation reaction at the surface and the carbon diffusion inside the steel sheet.It can be numerically solved to quantify the influences of annealing temperature and atmosphere on decarburization kinetics when the boundary conditions are properly determined.In case that a humid gas mixture is employed during annealing,the most influential process parameter is temperature rather than compositions of the gas mixture,because the diffusion of carbon in ferrite is the rate-limiting step.Therefore,a higher temperature is required for the efficient decarburization of the thicker silicon steel sheet using the industrial continuous annealing production line.展开更多
In order to investigate the influence on shale gas well productivity caused by gas transport in nanometer- size pores, a mathematical model of multi-stage fractured horizontal wells in shale gas reservoirs is built, w...In order to investigate the influence on shale gas well productivity caused by gas transport in nanometer- size pores, a mathematical model of multi-stage fractured horizontal wells in shale gas reservoirs is built, which considers the influence of viscous flow, Knudsen diffusion, surface diffusion, and adsorption layer thickness. A dis- crete-fracture model is used to simplify the fracture mod- cling, and a finite element method is applied to solve the model. The numerical simulation results indicate that with a decrease in the intrinsic matrix permeability, Knudsen diffusion and surface diffusion contributions to production become large and cannot be ignored. The existence of an adsorption layer on the nanopore surfaces reduces the effective pore radius and the effective porosity, resulting in low production from fractured horizontal wells. With a decrease in the pore radius, considering the adsorption layer, the production reduction rate increases. When the pore radius is less than 10 nm, because of the combined impacts of Knudsen diffusion, surface diffusion, and adsorption layers, the production of multi-stage fractured horizontal wells increases with a decrease in the pore pressure. When the pore pressure is lower than 30 MPa, the rate of production increase becomes larger with a decrease in pore pressure.展开更多
文摘Based on the principle of RH process and the mechanism of decarburization, a three-dimensional mathematical model to represent the flow and decarburization of molten steel was established. The model was verified and the effect of operating parameters on the process was investigated.
文摘An improved mathematical model to describe the decarburization process in basic oxygen furnaces for steelmaking is presented in this work. This model takes into account those factors or parameters that determine the bath-oxygen impact area, such as the cavity depth, the lance height, the number of nozzles and the nozzles diameter. In the thermal issue, the model includes the targeted carbon content and temperature. The model is numerically solved, and is validated using reported data plant. The oxygen flow rate and the lance height are varied in the numerical simulations to study their effect on the carbon content and decarburization rate.
文摘用顶吹 CO2 - Na OH溶液体系模拟了 RH- KTB顶吹氧溶氧过程。通过对碱液吸收 CO2 反应动力学的研究 ,考察了操作参数对 RH- KTB顶吹氧脱碳过程中溶氧反应的影响。结果表明 :提高气相中氧分压、增加提升氩气流量或采用低枪位喷吹都有利于加速溶氧脱碳。实验中还发现 :顶吹氧气流量对容积传质系数影响很小 。
文摘A mathematic model has been presented to predict the decarburization kinetics of grain-oriented silicon steel sheet in the gas mixture of N2–H2–H2O during annealing.This model is based on the carbon flux balance between the oxidation reaction at the surface and the carbon diffusion inside the steel sheet.It can be numerically solved to quantify the influences of annealing temperature and atmosphere on decarburization kinetics when the boundary conditions are properly determined.In case that a humid gas mixture is employed during annealing,the most influential process parameter is temperature rather than compositions of the gas mixture,because the diffusion of carbon in ferrite is the rate-limiting step.Therefore,a higher temperature is required for the efficient decarburization of the thicker silicon steel sheet using the industrial continuous annealing production line.
基金supported by the National Natural Science Foundation of China (No. 51234007, No. 51490654, No. 51504276, and No. 51504277)Program for Changjiang Scholars and Innovative Research Team in University (IRT1294)+3 种基金the Natural Science Foundation of Shandong Province (ZR2014EL016, ZR2014EEP018)China Postdoctoral Science Foundation (No. 2014M551989 and No. 2015T80762)the Major Programs of Ministry of Education of China (No. 311009)Introducing Talents of Discipline to Universities (B08028)
文摘In order to investigate the influence on shale gas well productivity caused by gas transport in nanometer- size pores, a mathematical model of multi-stage fractured horizontal wells in shale gas reservoirs is built, which considers the influence of viscous flow, Knudsen diffusion, surface diffusion, and adsorption layer thickness. A dis- crete-fracture model is used to simplify the fracture mod- cling, and a finite element method is applied to solve the model. The numerical simulation results indicate that with a decrease in the intrinsic matrix permeability, Knudsen diffusion and surface diffusion contributions to production become large and cannot be ignored. The existence of an adsorption layer on the nanopore surfaces reduces the effective pore radius and the effective porosity, resulting in low production from fractured horizontal wells. With a decrease in the pore radius, considering the adsorption layer, the production reduction rate increases. When the pore radius is less than 10 nm, because of the combined impacts of Knudsen diffusion, surface diffusion, and adsorption layers, the production of multi-stage fractured horizontal wells increases with a decrease in the pore pressure. When the pore pressure is lower than 30 MPa, the rate of production increase becomes larger with a decrease in pore pressure.
