Energy Efficiency Of Furnaces Research Articles

Procedure of Analysis and Control of Furnace Energy Efficiency

Procedure of Analysis and Control of Furnace Energy Efficiency

Improvement of Blast Furnace Energy Efficiency by Injection of Preheated Pulverized Coal Fuel with Iron Oxides

Improvement of Blast Furnace Energy Efficiency by Injection of Preheated Pulverized Coal Fuel with Iron Oxides

ENERGY EFFICIENT SOLUTIONS FOR SMALL CAPACITY ELECTRIC ARC FURNACES OF A FOUNDRY CLASS

The low specific power of the transformer in combination with the increased heat losses due to the geometrical factor and the unstable operation with long downtimes are predetermined by low technical and economic indicators of production, in comparison with the EAF of the "big" metallurgy. An urgent task is to search for low-cost methods to increase the energy efficiency of furnaces of this class by simulating the thermal work of the elements of the working space. Numerical simulation of heat transfer in the working space of foundry class AC EAF with a capacity of 3 tons has shown that with a duration of furnace downtime of 18–20 hours or more, replacing 40% of the walls lining and 16-20% of the roof lining by water cooled elements with a volumetric structure accumulating the skull, with using of “deep" bath with a reduced by 14–15% diameter of the radiating surface allows, at a given melting mass, to reach the energy consumption level of the furnace with a fully refractory lining and lower with a significant saving of refractories. Preloading scrap into the furnace in downtime increases energy efficiency, all other things being equal.

Exergy pinch analysis of a furnace in a primary oil refining unit

The article considers the issue of thermodynamic optimization of heat power equipment. The solution to this problem allows one to increase the energy efficiency of heat systems by reducing the energy resources consumption. The article compares the traditional (enthalpy) pinch method and the exergy pinch method. The exergy method of thermodynamic analysis allows one to take into account both quantitative and qualitative characteristics of thermal processes. A furnace that heats oil in the ELOU AT-6 primary oil refining unit was selected as an object of the study. The results obtained using the traditional pinch method showed that the furnace does not require optimization. However, the exergy analysis showed that the furnace has exergy losses. The method of exergy pinch analysis allows us to formulate and justify specific design measures aimed at increasing the furnace energy efficiency. Using the exergy pinch analysis, one can identify the unused exergy and determine the part in which the loss occurs.

Electric Arc Furnace Modeling with Artificial Neural Networks and Arc Length with Variable Voltage Gradient

Electric arc furnaces (EAFs) contribute to almost one third of the global steel production. Arc furnaces use a large amount of electrical energy to process scrap or reduced iron and are relevant to study because small improvements in their efficiency account for significant energy savings. Optimal controllers need to be designed and proposed to enhance both process performance and energy consumption. Due to the random and chaotic nature of the electric arcs, neural networks and other soft computing techniques have been used for modeling EAFs. This study proposes a methodology for modeling EAFs that considers the time varying arc length as a relevant input parameter to the arc furnace model. Based on actual voltages and current measurements taken from an arc furnace, it was possible to estimate an arc length suitable for modeling the arc furnace using neural networks. The obtained results show that the model reproduces not only the stable arc conditions but also the unstable arc conditions, which are difficult to identify in a real heat process. The presented model can be applied for the development and testing of control systems to improve furnace energy efficiency and productivity.

Improvement of Electric Furnace Energy Efficiency for Firing Vermiculite Due to “Zero Modules” Not Requiring Electrical Energy

Questions are considered for improving the energy efficiency of electric modular-pouring furnaces due to use of thermal exergy of expanding vermiculite grains. In order to create favorable conditions for transformation of accumulated heat into energy from final dehydration and structure formation a so-called “zero” module is introduced into the furnace construction, not requiring electrical energy. In contrast to other versions, this additional module is vibration-active and provides movement of expanded grains with single-layer continuous flow without breaks or gaps. This flow structure makes it possible to use heat accumulated by vermiculite and inert material most effectively.

Influence of carbothermic reduction on submerged arc furnace energy efficiency during silicon production

In this study, we investigated the exergetic efficiency and thermal energy source of the off-gas system of a submerged arc furnace, which varied from 27% to 35% and 47% to 55%, respectively, of the total energy supply. We used a case study to evaluate the thermal exergy in the off-gas of a real furnace, which exhibited an additional power capacity up to 2.7 MW amounting to 10% of the total energy supplied to the process (or 23% of the electrical power fed to the furnace.) We also determined the perfect negative correlation coefficients (r as the standard) between the exergetic efficiency and raw material consumption via linear regression and observed moderately positive relevance between power consumption and raw material consumption in the furnace. We attributed this correlation to increased graphitization and reduced resistivity of carbonaceous materials as the charging began sink slowly into the reaction zone and the charging temperature increased. Compared to coal, petroleum coke showed a significant impact on total power consumption according to the linear regression results; especially in regards to the fact that petroleum coke underwent graphitization more easily than coal as charging temperature increased.

Improving furnace energy efficiency through adjustment of damper angle

Numerous furnaces and boilers are extensively used in industrial and commercial facilities to generate thermal energy so that small improvements of the furnace thermal efficiency will amount to tremendous reduction of energy consumption and green gas emission. In this research, the furnace flue damper angle is adjusted to lower the pressure in the furnace for reducing the velocity of hot gas rising in the furnace. This allows more time for the heat to be transferred to the thermal flow that improves the furnace overall thermal efficiency. On the other hand, when the damper angle is adjusted from 45 to 39°, the pressure in the furnace rises from −14.7 to −9.3 mmH2O, the average fuel volumetric flow rate reduces from 751 to 491 m3/h, and the average temperature lowers from 949 to 909 °C in the radiation section and from 756 to 798 °C in the conventional section. Hence, about 1.7 × 106 m3 of fuel gas consumption can be saved, and 1.9 × 103 ton of CO2 emission can be reduced annually. The results confirm that simply by adjusting the flue damper angle of a furnace will achieve significant savings of energy and reduction of carbon dioxide emission.

Global algorithm for systematic retrofit of tubular process furnaces

Tubular process furnaces are widely used especially in the chemical and petrochemical process plants and refineries. Retrofit of a furnace is usually recommended for increasing plant capacity or improvement of the furnace (and/or plant) energy efficiency. Many different constraints of existing furnace design and operation are the reasons for which the retrofit of a furnace is a very difficult task. Main operational and geometrical constraints are taken into account in furnace retrofit integration approach created earlier. This approach was developed primarily for improvement of the furnace energy efficiency. When furnace retrofit for increasing the plant capacity is performed additional criteria have to be considered. Then fluid hydrodynamic behaviour plays an important role and influences the retrofit strategy. This problem is discussed in the paper and results in suggestion of the global conceptual algorithm for furnace retrofit strategy. Practical case studies demonstrate applicability of the proposed global furnace retrofit algorithm.

Effect of oxyfuel burner ratio changes on energy efficiency in electric arc furnace at Co-Steel Lasco

Trials were conducted on Co-Steel Lasco's electric arc furnace (EAF) to evaluate the effect of oxyfuel burner ratio changes on furnace energy efficiency and productivity. Carefully controlled trials with the collection of numerous process and sample data over 331 heats provided statistically significant results. The oxygen available for post-combustion in the furnace was increased by 19%. As the burners were operating at their maximum oxygen constraint, this was achieved by decreasing the natural gas consumption by 43%. Results of this study indicate that decreases in terms of specific electrical energy consumption (4·0%), power on time (5·0%), and tap to tap time (4·5%) were realised. Slag chemistry, electrode consumption, and yield were not affected. Measurement data support the finding that more heat was transferred into the steel with the post-combustion burners: a flat bath was achieved earlier; high bath temperatures were reached more quickly; power on time was reduced, leading to reduced electrical energy consumption. Analysis suggests that furnace thermal energy losses were reduced by less air inleakage, less incomplete methane combustion, and earlier achievement of foamy slag conditions.

“Energy efficiency in furnaces”

1.1 Metabrasive Ltd — The Company and Product Metabrasive Ltd is a wholly‐owned, British registered, subsidiary of a French Company, Wheelabrator‐Allevard S.A., which is based in the Isère region of France just north of Grenoble. That Company, which is itself 51% American owned, bought the steel abrasives business from Bradley & Foster Ltd., a part of Staveley Industries, in August 1980.