Hot blast stove automatic control in staggered parallel operation
|
Specific effect
In does not change the original hot-air furnace parameters conditions (the same calorific value of gas and burner ability, the same vault flue gas temperature and exhaust gas temperature and the same lattice brick weight and sent at the beginning of the wind temperature) can improve hot air temperature of the basic value about single oven air temperature drop of 25% (for example, single oven air temperature drop 60 degrees Celsius can improve the air temperature of 15 degrees Celsius, a single furnace air temperature drop 100 degrees Celsius, increased air temperature of 25 degrees Celsius).
Using the high precision digital hydraulic cold air regulating valve, hot blast stove intelligent thermal model, combined with "neurons matrix model deduction algorithm, with expert knowledge base of hot blast stove intelligent adaptive control algorithm, fuzzy control system etc., the hot air temperature fluctuations in the value of the control within plus or minus 5 degrees Celsius.
When the hot blast stove is converted to the air supply, the influence of the filling and cooling air is affected, and the initial hot air temperature in the furnace is reduced. By using the traditional staggered parallel feeding, two hot air furnace to send 50% air flow can not be changed, so the wind cycle in the start of 2-3 minutes, even if not against the cold wind, it will produce more than 50 degrees Celsius hot air cooling. After adopting the new technology of thermal parallel, the air flow rate of the first half cycle of the hot blast stove increases slowly from 0% to the first half cycle, and the short-term hot blast temperature drop can be reduced from 50 to 10 degrees Celsius.
For the blast furnace which has reached 1250-1300 degrees Celsius, the temperature of the dome can be reduced, and the risk of corrosion of steel plate welded joints can be reduced.
For factories that are not high enough to be used for high calorific value, the amount of high calorific value gas can be reduced.
When the air temperature is not increased, the air supply time can be prolonged, the frequency of the furnace is reduced, and the high temperature air quantity discharged during the changing of the furnace is reduced.
The new design does not require the highest wind temperature of the hot blast stove, can reduce the weight of lattice brick to save investment.
Interleaving is "two burning and two air", reduce the waiting time of the hot blast stove, circulation is more compact and reasonable, reduce heat loss and improve the thermal efficiency;
The single furnace feeding period is prolonged, and the frequency of the furnace is reduced, and the use efficiency of the hot blast stove is improved;
At the beginning and end of the air supply, the temperature difference of the heat storage room brick is large, so the heat storage capacity of the grid brick of unit heat storage room is increased, so that the air temperature can be improved, or the heat storage area can be reduced when the same wind temperature is same;
In the combustion period, because of the difference in temperature of flue gas in the dative brick, high heat exchange efficiency, thermal efficiency is high. The experimental data show that the temperature efficiency of the staggered parallel connection is about 4% higher than that of the single wind;
According to the requirement of blast furnace smelting, the automatic control system of the air temperature is automatically adjusted;
The mixed air valve is not mixed with the cold air to the hot air supervisor, which effectively utilizes the waste heat of the low temperature warm air furnace, and reduces the energy consumption;
Two hot air stove at the same time, reduce the flow resistance, air pressure fluctuation is smaller in furnace;
The system was put into production and use at No. 5 blast furnace in Wuhan Iron and Steel Corporation in July 2009.
Reference:
