Optimal Utilization System of Electric Furnace Flue Gas Waste Heat Based on Multi-pressure Mode

Abstract

The invention discloses an optimal utilization system of electric furnace flue gas waste heat based on a multi-pressure mode, which includes a first vaporization cooling flue and a second vaporization cooling flue connected sequentially from the flue gas outlet of the water-cooled elbow above the electric furnace along the flue gas flow direction. channel, combustion settling chamber, third vaporization cooling flue, waste heat boiler, high-pressure evaporator, high-pressure economizer, medium-pressure evaporator, and medium-pressure economizer in the waste heat boiler are arranged in sequence along the flue gas flow direction, the first The vaporization cooling flue and the furnace door of the combustion settling chamber are cooled by a low-pressure steam-water system to generate low-pressure steam; the second vaporization cooling flue, the furnace cover of the combustion settling chamber, and the medium-pressure section of the waste heat boiler adopt a medium-pressure steam-water system to generate medium-pressure Steam; the third vaporization cooling flue and the high-pressure section of the waste heat boiler adopt a high-pressure steam-water system to generate high-pressure steam, and the output steam of the high-pressure and medium-pressure drums passes through the heat accumulator and superheater to drive the steam turbine to work. The invention divides the steam-water system into three-pressure systems, and realizes cascaded optimized utilization of energy.

Description

technical field [0001] The invention relates to the technical field of energy saving in the iron and steel industry, in particular to an optimal utilization system of electric furnace flue gas waste heat based on a multi-pressure mode. Background technique [0002] In the process of electric furnace smelting, a large amount of high-temperature flue gas will be produced. These high-temperature flue gases not only take away a large amount of heat energy, but also affect the operation of downstream dust removal equipment, thereby causing environmental pollution problems. [0003] In recent years, as iron and steel enterprises pay more and more attention to energy saving and emission reduction, how to fully recover the sensible heat in the high-temperature flue gas in the steelmaking process and turn "waste" into treasure has become an issue of increasing concern to steelmaking enterprises. [0004] At present, the single-pressure waste heat recovery method is adopted in engine...

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Problems solved by technology

[0004] At present, the single-pressure waste heat recovery method is adopted in engineering for the waste heat recovery of electric furnace flue gas. There is a problem in this waste heat recovery method, that is, the utilization of flue gas waste heat is limited to a certain extent, generally around 200°C, and there is still a large space for utilization.

On the other hand, since the temperature of the flue gas is very high, while the temperature of the soda-water side is relatively low, the heat exchange with such a large temperature difference causes an excessive heat exchange loss, the effective utilization of energy is greatly reduced

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