Energy efficient solutions for EAF steelmaking

2018 ◽  
Vol 1 (88) ◽  
pp. 18-24 ◽  
Author(s):  
S.N. Timoshenko ◽  
A.P. Stovpchenko ◽  
Yu.V. Kostetski ◽  
M.V. Gubinski
Keyword(s):  
Mass Transfer ◽  
Spatial Structure ◽  
Heat And Mass Transfer ◽  
Heat Loss ◽  
Energy Efficient ◽  
Low Cost ◽  
Efficient Solutions ◽  
Arc Furnace ◽  
Aspiration System ◽  
Geometry Design

Purpose: To review an advanced solutions to improve the energy efficiency of electric arc furnace (EAF), and presentation of own new efficient low-cost solutions with regard to needs of electrometallurgical complex of Ukraine. Design/methodology/approach: Numerical simulation and industrial experiment is used. The patterns and parameters of heat and mass transfer processes, hydromechanics in a steelmaking bath of an arc furnace, thermal operation of water-cooled elements and gas dynamics in EAF workspace, are the subject scope of the paper. Findings: Energy-efficient solutions for steelmaking: bath geometry, design features of water-cooled elements (WCE), distributed aspiration system, and the mid-temperature scrap preheating. Research limitations/implications: Influence of the bath depth on heat and mass transfer and heat loss by radiation; influence of the spatial structure of WCE on heat loss by radiation; the dispersion of aspiration on the amount of fugitive emissions through electrode gaps are established. Practical implications: Grounds to improve EAF melting space, water-cooled elements, aspiration system and utilization of energy loss are obtained. Use of the set of solutions in 120-ton EAF can reduce energy consumption by 56-68 kWh/ton. Originality/value: The new concepts of deep steelmaking bath, WCE with spatial structure and system of dispersed aspiration of the EAF are elaborated.

scholarly journals Energy-efficient solutions of foundry class steelmaking electric arc furnace

2021 ◽  
pp. 81-87
Author(s):  
S.M Timoshenko ◽  
M.V Gubinski ◽  
E.M Niemtsev
Keyword(s):  
Mass Transfer ◽  
Energy Efficiency ◽  
Energy Loss ◽  
Heat And Mass Transfer ◽  
Energy Efficient ◽  
Refractory Lining ◽  
Efficient Solutions ◽  
Arc Furnace ◽  
Transfer Processes ◽  
Mass Transfer Processes

Purpose. Substantiation of solutions aimed at reducing heat losses, mainly, by refractory lining during forced downtime and by steelmaking bath in conditions of traditionally low specific power of transformer. Methodology. Mathematical modeling of heat and mass transfer processes and numerical experiment. Findings. A mathematical model of energy-technological processes in arc furnace workspace has been developed to analyze and minimize energy consumption in daily production cycle. Geometrical and operating parameters are taken into account, in particular: variation in arcs energy efficiency at evolution of wells in charge under electrodes during melting process; circulation of melt due to bubbling with inert gas through bottom porous plug; energy loss on heat accumulation by refractory, with cooling water and off-gas. Originality. For the first time, the concept of increasing energy efficiency of arc furnace has been substantiated, based on the following set of solutions: increase in specific electrical power by reducing of charge at given productivity; reduction of bath shape factor (ratio of diameter to depth) from traditional 5 up to 2.5 by deepening and, accordingly, its radiating surface; optimization of walls and roof cooled surface relative area, where massive heat-absorbing refractory lining is not used; application of energy-saving water-cooled elements with spatial structure that promotes formation of heat-insulating and heat-accumulating slag filling. Practical value. Implementation of the set of energy-efficient solutions in conditions of typical 6 and 12-t foundry class arc furnaces provides reduction in power consumption and refractory expenditure by 1315 and 2830% respectively without significant changes in production infrastructure due to reducing energy loss, mainly, for accumulation of heat by refractory lining, and intensification of heat and mass transfer processes in forcibly stirred deep bath.

Experimental and Theoretical Studies on Air Humidification by a Water Spray for Humid Air Turbine Cycle

2006 ◽  
Author(s):  
Zhen Xu ◽  
Yunhan Xiao ◽  
Yue Wang
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Pressure Loss ◽  
Low Cost ◽  
Packed Bed ◽  
Transfer Coefficients ◽  
Humid Air ◽  
Two Phase ◽  
Spray Tower ◽  
Air Turbine

Humidification of compressed air is important for humid air turbine cycle. Earlier studies paid more attention to packed bed towers. However, a spray tower has inherent advantages such as less pressure loss and low cost. In this study, a pressurized model spray tower was established for the experiments. A specially designed air diffuser was installed to achieve uniform air velocity profiles over the cross section and a mist eliminator was used to trap the water droplets in the outlet air. Performance of the tower was tested at different pressures and water/air ratios. Pressure loss was measured and analyzed at different air velocities. A comprehensive analysis of the humidification process in the spray tower was carried out. A mathematical model considering droplet motion and conservation of heat and mass was developed to predict heat and mass transfer in the water droplet-air two-phase flow. Local heat and mass transfer coefficients over height of the tower were calculated. It has been shown that the parameters of outlet air and water can be calculated within a maximal error of 7.3% compared with the experiment results. Droplet size is a main parameter that affects operating performance of the spray tower. It has also been indicated that pressure loss in the spray tower is low and this will benefit its application in HAT.

Combined Heat and Mass Transfer in Porous Media Heat Exchanger

2002 ◽  
Author(s):  
Adriana M. Druma ◽  
Khairul M. Alam
Keyword(s):  
Mass Transfer ◽  
Porous Media ◽  
Heat Exchanger ◽  
Heat And Mass Transfer ◽  
Energy Recovery ◽  
Low Cost ◽  
Porous Matrix ◽  
Air Stream ◽  
The Matrix ◽  
Heat And Moisture

A numerical and experimental study of heat and mass transfer has been carried out for an energy recovery ventilator with a porous media heat exchanger. The energy recovery ventilator selected for this study has a rotary periodic heat exchanger that can transfer heat and moisture from one air stream to another. Such heat exchangers can be operated with high effectiveness by using a low-cost porous matrix as the heat exchanger medium. The influence of porosity in the matrix has been studied numerically and the performance of the energy recovery ventilator in recovering both heat and moisture has been modeled.

Numerical modeling of energy efficient solutions of foundry class electric arc furnaces.

2020 ◽  
Vol 23 (2) ◽  
pp. 77-86
Author(s):  
S. TIMOSHENKO ◽  
◽  
E. NIEMTSEV ◽  
Keyword(s):  
Mass Transfer ◽  
Numerical Modeling ◽  
Heat And Mass Transfer ◽  
Heat Loss ◽  
Basic Unit ◽  
Specific Power ◽  
Water Cooling ◽  
Transfer Processes ◽  
Arc Furnaces ◽  
Mass Transfer Processes

Research is aimed at reducing the energy loss of foundry class arc furnace, which belongs to energy-consuming units with a non-rhythmic work schedule, and characterizes by low energy efficiency. Method of numerical modeling substantiates the concept of furnace modernization, which consists in rising the specific electric power by lowering the capacity at constant productivity, relative increasing of the liquid bath depth, reducing accumulation heat loss by refractory lining through introduction of energy saving water-cooled elements with a spatial structure in its local areas and intensification of heat and mass transfer processes in the "deep" bath with pneumatic stirring. It is determined that for arc furnaces with capacity of 12 and 6 tons, working in one shift, it is rational to reduce the capacity to 6 and 3 tons respectively and the bath shape factor (ratio of diameter to depth) from 5 to 2.5; installation of water-cooled elements in central endurance critical part of the roof and upper parts of the walls with coverage of 0.20-0.32 and 0.5-0.8 of working surface, respectively. With regard to the economy of heating systems, the expansion of the cooling system for the economic efficiency of modernization is 12 tons of chipboard with magnesite lining, so in the small world, dinas lining. For 6 t furnaces of water-cooling elements at the same time the magnesite lining is also effective, the protector is more cheap acidic lining (dinas), however, the water-cooling elements require a larger analogue. With available supply transformer, the specific power increases to 1 MVA/t, which will allow, due to intensification of heat and mass transfer processes, provide quantitative and qualitative indicators of production with lower, compared to the basic unit, heat loss. The implementation of proposed solutions will reduce energy consumption by 75 kWh/t and, taking into account the cost of refractory, provide an economic effect of 320-515 UAH/t.

Analysis of heat and mass transfer to determine heat loss and the rate of condensation of the MVSTs off-gas ducts

1992 ◽  
Vol 138 (3) ◽  
pp. 389-401
Author(s):  
M.A. Ebadian ◽  
G. Yang ◽  
E. Bigzadeh ◽  
J.F. Walker ◽  
T.J. Abraham
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Heat Loss

Analysis of Heat Processes in the Energy Supply System of a Gas-Using Feed Boiler

2020 ◽  
Vol 67 (1) ◽  
pp. 71-77
Author(s):  
Anatoliy M. Shuvalov ◽  
Aleksey N. Mashkov ◽  
Dmitriy A. Tikhomirov
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Power Supply ◽  
Energy Efficient ◽  
Energy Supply ◽  
Power Supply System ◽  
Energy Savings ◽  
Self Regulation ◽  
Supply System ◽  
Energy Supply System

The energy audit conducted on the use of fuel and energy resources in agriculture in the Tambov region showed that energy costs in the cost of production of agricultural products, depending on the type of products produced (milk, meat, vegetables grown in greenhouses, etc.) and their production technology, reach 15-50 percent. On large livestock farms, forage shops and inter-district feed mills are being built for the feed production. Gas-fired cooking cauldrons of low capacity (of 40-250 kilogram per hour) are mainly used for small and private farms. Analysis of low-power cooking boilers has shown that it is possible to improve their energy supply system by applying a method of regulating gas in proportion to the consumed heat flow. Energy savings can reach 40-50 percent. (Research purpose) The research purpose is in designing an equation system for mathematical description of the heat and energy balance of a gas-using cauldron with self-regulation of power to identify energy-efficient modes of its operation. (Materials and methods) Methods of system analysis and synthesis has been used. of knowledge existing in the field of ongoing research on the development of a gas-using digester with self-regulation of power. The methods are based on the theory of heat and mass transfer. (Results and discussion) The article presents a theoretical analysis of heat and power processes occurring in the power supply system of a cauldron with self-regulating power. The authors have designed a heat balance equation describing the processes of heat and mass transfer in a cauldron to identify effective modes of operation of such a power supply system. The article presents derived formulas for determining the useful heat for heating the product in the cauldron, heat loss for heating metal structures, from the enclosing structures to the environment, with outgoing exhaust gases, and from chemical underburning. (Conclusions) The article presents a system of equations that allows to mathematically describe the processes of heat and mass transfer in a gas-using cauldron with self-regulation of power to identify the most energy-efficient modes of its operation. It was found that by improving the power supply system of cauldron by applying a method of regulating gas in proportion to the consumed heat flow, it is possible to achieve energy savings of up to 40-50 percent.

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