Control method capable of realizing precise control of bottom-blowing gas during refining and vacuumizing in VD furnace

Abstract

The invention discloses a control method of realizing the precise control of bottom-blowing gas during refining and vacuumizing in a VD furnace. The control method comprises the following steps of reading real-time process parameters by virtue of a programmable logic controller (PLC) of a VD furnace control system and transmitting the real-time process parameters of the VD furnace to a programmable logic controller (PLC) of a VD furnace bottom-blowing gas control system through an industrial communication module; setting a definite specific stirring power value according to the process needs, calculating the output bottom blowing argon flow based on the calculation formula epsilon is equal to 6.18*10<-3>QT/W*[(1-273/T)+ln(P1/P2)] and finally transmitting the bottom blowing argon flow to an implementation element so that the intelligent control of the bottom blowing argon flow is achieved. The invention provides a method for implementing the real-time intelligent control of the bottom blowing argon flow through PLC, good real-time property is achieved, the flow value is accurately regulated and the bottom blowing argon flow can be automatically and rapidly adjusted according to changes in the degree of vacuum.

Description

technical field [0001] The invention relates to the technical field of steelmaking automation, in particular to a control method for realizing precise control of bottom-blowing gas during refining and vacuuming of a VD furnace. Background technique [0002] Vacuum refining technology is an effective measure to degas and reduce the impurity content of steel and improve the cleanliness of steel. At present, the most typical vacuum treatment methods are VD method, RH method and VOD method. Among them, the VD (vacuum degassing) vacuum degassing method is widely used because of its low cost and good degassing, desulfurization, and inclusion removal effects. [0003] In recent years, the continuous development of out-of-furnace refining technology requires that the effect of out-of-furnace refining should be better, the time should be shorter, and it must have a fast process rhythm that can match electric arc furnaces and converters. The argon-blowing steelmaking technology at t...

AI Technical Summary

Problems solved by technology

[0008] 1. Manually adjust the flow rate of argon gas. If the amount of argon blowing is not properly controlled when the vacuum degree changes, it will easily cause molten steel splashing or slag overflow (if the flow rate is too small, the surface of the molten steel will not roll enough, and the decarburization efficiency will be low; if the flow rate is too large , molten steel splashing, slag overflow);

[0009] 2. The current flow control of argon blowing at the bottom of the VD furnace often does not output measurement values ​​that can be used for process data analysis

In terms of control methods and means, either continuous linear adjustment cannot be achieved, or the response time is too long (for example, greater than 6 seconds) and there is serious overshoot, and there is a problem of poor adjustment accuracy.

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