Boguslavskaya Tatyana Nikolaevna

The subject of graduate work:


«Analysis of the influence of various factors on the specific consumption of fuel 3 zone heating furnaces»


Scientific adviser: profesor Anatoli Tuyahov


Introduction

Metals - one key and the most energy intensive industries operating in the harsh climate in Ukraine, huge, but hard-to resources, and increased transportation costs. To develop in the face of international competition, metallurgy should use all the technology development, technology, economy, energy and material resources. In these, areas of large reserves associated with an increased efficiency of heating devices, through which ran into thousands, and including, there were more than 400 large furnaces rolling mills. Many of the problems of heating furnaces identified deficiencies structures and the large difference in their ages. Partly for that reason, even in the planned economy, there was a large spread of performance furnaces, which increases when not fully rolling equipment. But it also points to the reserves for increasing the efficiency of units by improving the design and economical expenditure of energy and material resources. Determination of prospective trends of resource and energy conservation by heating the metal is not possible without improving the theory, design and technology of heating furnaces of the metal.

Topical issue

Energy and resources is one of the main components of modern technologies, particularly in metallurgy and mechanical engineering. Comparing the performance of the 3-zone heating furnaces designed to heat the billet under rolling with similar units in other enterprises, including overseas have shown that the specific consumption of fuel higher by 30-40%.

The purpose and objectives

Reduction in fuel consumption during the heating of billets.

The practical value of the work

Consider the specific ways to implement energy-saving stoves in modern metallurgy and engineering.

1 way. Reducing difference of entalpiy achieved in practice by increasing the initial temperature of the metal in cast him into the oven. The so-called "hot Posad" is possible while maintaining the heat in the metal, it has received in the previous redistribution, including the heat of crystallization of ingots. An example of such an energy-saving technology are the casting-rolling modules. In some cases it is possible to exclude the intermediate heating of the metal between two rolling mills, ie bring the heat deficit to zero by reducing heat losses during transport rolls from one camp to another. At the mills Zaporizhstal and them. Illich (Mariupol) technology for "in transit" rolling slabs in continuous sheet mills, in which 95% of the slabs rolled without intermediate heating in the reheat furnaces. In this case the specific consumption of fuel in reheat furnaces reduced from 85 to 15 kg / t. Reduce difference of entalpiy can also by reducing the heating temperature of the metal in the furnace. However, we must remember that this will entail not only reducing fuel consumption, intoxication and decarbonization of the metal, but will also increase energy consumption by rolling and is likely to reduce the lifetime of the rolls. Thus, the choice of billet heating temperature is the optimization problem of minimizing the total cost of the processes of heating and rolling.

2 way. The loss of heat from the workspace to occur in any oven, but they are especially significant in the heating and thermal furnaces. The lining of these furnaces, made of fireclay brick absorbs about 3 times more heat than the melt metal. Reduce heat to warm up the lining is achieved by replacing the chamotte refractories mullite-siliceous fiber boards, production of which was established in Ukraine and Russia. In the continuous heating furnaces through the use of fibrous materials for thermal insulation of walls and water-cooled beams in conjunction with the concrete shell of the loss of heat from the working space reduces to 3-5% of the thermal power of the furnace.

3 way. To improve the CIT used the following activities:

- Reducing the temperature of flue gas reheat furnaces by heat exchange with the metal in an unheated area;

- A decrease of the combustion products per unit of fuel by enriching air with oxygen, by increasing the heat of combustion of fuel, as well as by complete combustion with minimum excess air;

- Seal the working space and regulation of gas pressure in the furnace to eliminate air leaks.

However, the most effective means of increasing KIT, savings

Fuel and energy saving solution to the problem is the utilization of heat from the furnace flue gases, in particular, by heating the air and gaseous fuel in a recuperator or regenerator. In the recuperator the proportion of heat transmitted through the air toward the heat of the outgoing flue gases is 30-40%. The remainder of the heat is carried into the atmosphere.

The reasons for the low efficiency of existing energy recovery are:

1. The temperature of flue gases in front of a metal heat recovery can not be higher than 900-1000 ° C in terms of its durability.

2. The actual temperature of the smoke at the entrance to the recuperator significantly lower as a result of suction of cold air in the smoke channel of the furnace, so the temperature of the heated air (or gas) does not exceed 300-400 ° C.

3. Ceramic recuperators can heat the air to a higher temperature, but they are cumbersome and leaky. Leaks of air through leaks reach 50%, resulting in reduced heat output of the furnace is broken and burning control.

Conclusion

Thus, we have made an analysis of the influence of various factors on the specific consumption of fuel in a continuous heating furnaces, as well as suggesting ways to save energy.

Literature

1. Кривандин В.А. Металлургические печи. – М.: Металлургия, 1962 г. – 461 с.

2. Грум-Гржимайло В.Е. Пламенные печи. -М.-Л.: Госмашметиздат, 1932.

3. Сацкий В.А. Технический прогресс – залог высокопроизводительной работы комбината. // Металлургическая и горнорудная промышленность, 2000, № 4– С. 1-3.

4. Царицын Е.А. Техническое развитие ММК им. Ильича // Металлургическая и горнорудная промышленность, 2000, № 4. – С. 3-6.