Emergency blowout control method for large slab heating furnace

Abstract

The invention relates to an emergency blowout control method for a large slab heating furnace. The emergency blowout control and alarm of the slab heating furnace is realized by the steps of reasonably selecting automatic blowout conditions and technological parameters, setting a blowout interlocking plant and a movement time sequence, changing the control mode for the coal gas control valve, adding a sound alarm for the low-pressure blowout alarm signal of coal gas, air and instrument air in the blowout procedure, and popping up an alarm picture. The invention has obvious effect on the heating furnaces of hot-strip 1700 mm and 1780 mm production lines. Even when coal-gas low pressure, combustion-fan power-fail, instrument-air low pressure, evaporation cooling system power-cut and other faults occur, no safety or equipment accident happens. Thus, the invention greatly reduces the frequency and time of heating furnace blowout and creates favorable conditions for smooth steel rolling production and yield enhancement.

Description

technical field [0001] The invention belongs to the field of steel rolling thermal control, and in particular relates to a control method for setting automatic emergency shutdown conditions and interlocking actions of a large slab heating furnace. Background technique [0002] The gas fuel used in the heating furnace is mixed gas. In the production process, once the gas or combustion air pressure is too low, it is easy to cause gas to enter the air pipe or air to enter the gas pipe, causing major safety and equipment accidents such as fire and explosion. Therefore, for large slab heating furnaces, All must be equipped with automatic emergency cut-off measures, that is, the emergency automatic shutdown function of the heating furnace, to ensure the safety of the slab heating furnace. [0003] However, most of the heating furnaces of the 1700mm production line and 170mm production line of most hot-rolled strip mills in my country currently have more or less defects in the eme...

AI Technical Summary

Problems solved by technology

[0004] First, too many shutdown conditions are set, and the set values ​​are inaccurate, or too high or too low

For example, the automatic shutdown conditions are set as follows: gas main pipe pressure is lower than 5KPa; air main pipe pressure is lower than 7KPa; instrument air source pressure is lower than 0.18MPa; cooling water pipe pressure is lower than 0.35MPa; discharge end wall, flue water beam Low cooling water flow rate; abnormal vaporization cooling system, etc., if any of them reaches the set value, the control system will enter the automatic shutdown procedure, resulting in frequent shutdown of the heating furnace, seriously affecting the smooth progress of production

[0005] Second, the equipment and timing of the shutdown interlock action are unreasonable

Moreover, due to the unreasonable design of the equipment and timing sequence of the automatic shutdown interlocking action, and the unreasonable cut-off method of the gas control valve, there have been emergency situations such as low gas pressure, power failure of the combustion-supporting fan, combustion control CPU, power failure, and instrument gas supply interruption. There have even been accidents where the main pipeline gas backfired and exploded due to the stop of the meter gas source and the stop of the gas, and caused the sealing leakage of the blocking plates on both sides of the gas pipeline, which caused a serious threat and impact on production and equipment safety.