Flue fan control method based on dynamic decarburization rate of molten pool of combined blown converter

Abstract

The invention discloses a flue fan control method based on the dynamic decarburization rate of a molten pool of a combined blown converter. The flue fan control method comprises the following steps: a, establishing a multi-parameter coupling database; b, calculating top-blowing stirring strength, bottom-blowing stirring strength, oxygen lance impact depth and oxygen lance impact area; c, calculating dynamic characteristic indexes of the molten pool; d, the carbon content of the molten pool is measured, and the corresponding molten pool decarburization rate is calculated; e, constructing a matching relation mathematical model between the molten pool decarburization rate and the molten pool dynamic characteristic index; f, calculating dynamic characteristic indexes of the molten pool in real time to obtain a predicted value of the decarburization rate of the molten pool; g, calculating the instantaneous generation amount of flue gas; and h, regulating and controlling the rotating speed of the flue fan in real time according to the instantaneous generation amount of the flue gas. According to the method, on the basis that the matching relation mathematical model between the molten pool decarburization rate and the molten pool dynamic characteristic index is constructed, synchronous linkage of the air draft amount and the amount of gas generated by the molten pool is achieved, the converter flue gas air combustion coefficient approaches zero, and the quality of recycled coal gas is greatly improved.

Description

technical field [0001] The invention relates to a flue fan control method based on the dynamic decarburization rate of a reblown converter molten pool, which can increase the calorific value of recovered gas, and belongs to the technical field of metal smelting. Background technique [0002] Combined blowing converter steelmaking process and gas recovery are high-temperature multi-phase metallurgical processes that cooperate with each other. Affected by the movement of the molten pool and the concentration of elements, the decarburization rate presents a nonlinear change characteristic of "low-high-low". During the period of low decarburization rate, the excess oxygen and the reaction of sucked air and CO in the furnace gas reduce the heat recovery of the recovered gas. value. In the prior art, static models or end-point predictions are mostly used to predict the carbon content of the converter bath, and a differential pressure gauge is installed at the furnace mouth to rea...

AI Technical Summary

Problems solved by technology

Under normal production conditions, most converter flue fans operate at a constant speed, which does not dynamically match the decarburization rate of the molten pool and the amount of flue gas generated, making it difficult to improve the quality of recovered gas

[0003] The Chinese patent "A Method for Recovery of Converter Gas" (Application No. 02154179.5) discloses a method for recovery of converter gas. Without effective control, the volume of CO gas in the gas is doubled after combustion, and the particle size of the soot is fine and difficult to purify after oxidation. The unit calorific value of the recovered gas is low, and the recovery volume is small

[0006] None of the above gas recovery methods realize the synchronous linkage between the air volume of the flue fan and the gas volume generated by the reaction of the converter molten pool, and the prediction of the carbon content of the converter molten pool is based on the parameters of the furnace gas, which is a causal dislocation, resulting in the existence of prediction results. Big error, low fan speed control accuracy, not conducive to the improvement of the calorific value of recovered gas

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