Українська   Русский
   

Abstract

Content

Introduction

In this paper, possible options for improving the efficiency of the arc steel furnace were considered. The characteristics and design of the Arc steel furnace are considered. The possible problems in the operation of furnaces on the supply network. Variants of increase of value of internal efficiency at the expense of energy resources are offered.

1. Relevance of the topic

In the development of effective steelmaking processes in arc steel furnaces it is necessary to solve a complex of complex problems: achieving maximum furnace performance and maximum efficiency, obtaining the necessary quality of steel, minimizing the cost of charge and materials.

It should be noted that as the cost of electricity is reduced, as well as due to the increase in the capacity of arc units, thereby reducing the consumption of electricity and materials for the smelting of 1 ton of steel, the difference in the cost of metal conversion in the arc and open-hearth furnaces is reduced. In recent years, not only high-alloy steels are smelted in powerful Arc steel furnaces.

2. Technological process of Arc steel furnace

Improving the performance of Arc steel furnace should be considered as a complex task, the solution of which is to reduce the duration of the three main periods of melting: preparatory (production, filling, filling charge), energy (melting charge), and technological (oxidation and reduction periods of melting). Reducing the duration of the melting of the charge and the entire melting is achieved by using the concept of “heavy-Duty Arc steel furnace” - increasing the specific power of the transformer to 800÷1000 kV·T. This, in turn, determines the electric mode of the melting period – operation at elevated voltage levels, with long arcs and an increased power factor throughout the melting period.

During the melting period, short circuits often occur due to the collapse of the charge and with frequent arc ignition. The number of short circuits is tens and sometimes hundreds for melting. The most frequently occurring single-phase short circuit during the burning phase in the rest of the arcs. Short-circuit currents are limited by the furnace transformer and an additional reactor to a value of 2,5÷3,5 times the rated current. The reactor is often installed in the same tank as the transformer.

The Arc steel furnace works, as a rule, round the clock with stops on repair and routine inspection. The cycle of operation is determined by the alternation of melting with the shutdown of the furnace for metal discharge, refueling and loading. A large unit capacity of furnace units determines the high cost of electric energy, so the energy service of industrial enterprises and technologists is faced with the task of choosing a rational mode of operation of the furnace, which on the one hand provides high performance, and on the other – the minimum consumption of electricity.

3. The work an electric Arc steel furnace

Arc steel furnace allow short-term power interruptions, but with long shutdowns without emptying the furnace, the furnace can fail.

One furnace can not create a uniform load, since there are periods of disconnected state of the furnace (when loading the furnace, when casting metal, slag, etc.), but already with two or more furnaces, you can create a more uniform load schedule.

For the correct choice of mode of operation Arc steel furnace knowledge of electrical characteristics is not enough, the Arc steel furnace as a technological unit is characterized primarily by specific power consumption and performance.

Therefore, the choice of a rational mode of operation of the Arc steel furnace are on the performance characteristics, which are electrical and technological characteristics

4. Measures to save energy in Arc steel furnace

  1. The maintenance of the furnace and all equipment (especially the automatic control mode Arc steel furnace) in good technical condition. Compliance with the scheduled preventive maintenance schedule;
  2. The right choice of electric furnace operation: the steps of the voltage transformer and current arc;
  3. Reduce downtime of the furnace, the minimum residence time, particle Board open while booting arch;
  4. Periodic inspection by infrared thermometer of the state of contact connections;
  5. Use of high quality materials for lining the furnace and electrodes;
  6. Increasing the power factor and quality of electricity by using capacitor banks and filters of higher harmonic components.

Conclusion

In modern heavy-duty arc steel furnaces the value of the actual efficiency is about 55–60 %. This is due to the design and technological mode of the furnace, which causes significant energy losses in its working space.

Increasing efficiency by reducing losses can be achieved by changing the design and improving the technological regime through the redistribution of the main energy components..

References

  1. Энерготехнологические установки (конспект лекций)/Состав.: В. П. Муха – Донецк; Издательство ДонНТУ, 2008. – 240 с.
  2. Лопухов Г. А. Ближайшие перспективы развития мировой чёрной металлургии / Г. А. Лопухов / Электрометаллургия. – 2001. – № 1.
  3. Гаврилов Ф. А., Цыбуля В. В. Влияние дуговых сталеплавильных печей малых объёмов на работу электрооборудования / Ф. А. Гаврилов // Электротехника и электроэнергетика Вестник приазовского национального технического университета № 20.
  4. Николаев А. А., Корнилов Г. П., Анохин В. В. Повышение электрической мощности дуговой сталеплавильной печи за счёт компенсирующих устройств / А. А. Николаев // Russian Internet Journal Electrical Engineering. 2015.