Automatic control method for air-fuel ratio of hot-blast stove

Abstract

The invention discloses an automatic control method for the air-fuel ratio of a hot-blast stove. The method includes the following steps that S1, in the ignition stage, after a control system of the hot-blast stove receives a combustion signal, air and fuel gas are input into the hot-blast stove according to the optimal air-fuel ratio; S2, after a signal indicating that ignition of the hot-blast stove is completed is received, an air-fuel ratio dual-PID controller is started, dual PID includes remaining oxygen PID and arch crown temperature PID, and maximum values of the two PID control results are output; and S3, after a banking signal of the hot-blast stove is received, the control system of the hot-blast stove stops working. By means of the automatic control method for the air-fuel ratio of the hot-blast stove, the optimal air-fuel ratio can be output all the time, and it is guaranteed that coal gas is efficiently and fully combusted; the arch crown temperature is controlled to be stabilized at the a target arch crown temperature, and it is guaranteed that the combustion process is safe and stable; and automatic and stable switch for different requirements of the air-fuel ratio in various stages can be achieved.

Description

technical field [0001] The invention relates to the field of automatic control of hot blast stoves, in particular to an automatic control method for air-fuel ratio of hot blast stoves. Background technique [0002] The hot blast stove is an important link in the ironmaking process. The hot air heated by it provides the combustion temperature and oxygen for the coke and coal injection in the blast furnace. Increasing the air temperature can effectively reduce the coke ratio, reduce the amount of coal injection, and increase the pig iron production . According to production statistics, every time the air temperature is increased by 100°C, the coke ratio can be reduced by 2.5% to 3.5%, and the output can be increased by 2.5% to 3.5%. At the same time, the hot blast stove is the most important gas consumption link in the ironmaking process and even the entire steel process. Under the premise of ensuring high blast temperature, reducing the gas consumption of the hot blast stove...

AI Technical Summary

Problems solved by technology

[0010] The technical problem to be solved by the present invention is to provide a hot-blast stove air-fuel ratio that can ensure efficient combustion of gas and precisely control the air-fuel ratio in three stages in view of the defect that it is difficult to accurately control the air-fuel ratio of multiple stages in the hot-blast stove in the prior art. Fuel Ratio Automatic Control Method

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