JPH0250151B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method for controlling the fire-off time and exit temperature of a coke oven. The present invention relates to a method of controlling fire-off time and kiln exit temperature in so-called programmed heating operation in which the amount of heat (fuel amount) supplied is changed according to a pattern.

(Prior art) In a coke oven, the set furnace temperature of the combustion chamber for each period of the carbonization process, that is, the heating pattern, is determined in relation to the amount of heat consumed, and the amount of heat supplied is controlled using this as a target value, and a series of carbonization cycles Programmed heating methods have been proposed to reduce the total amount of heat consumed. The coke oven heating control method described in JP-A-59-20379 is a method previously proposed by the present applicant as one of the program heating methods.

(Problem to be solved by the invention) However, in this programmed heating method, as well as in the conventional heating method using a constant fuel supply, fluctuations in the amount of coal charged, its moisture content, etc. Fire-off time and kiln exit temperature often vary from kiln to kiln due to variations in heat load due to various factors, and specific methods to appropriately deal with such variations have yet to be established. Not yet.

(Means for solving the problems) The present invention provides the following steps in performing the above program heating:
The set furnace temperature pattern of the combustion chamber is corrected based on fluctuations in heat load factors and the actual fire-off time and kiln exit temperature of each kiln, and the amount of heat supplied is controlled using this as a target value. This provides a method of controlling the falling time and kiln exit temperature to minimize deviations from target values.

In other words, the present invention provides a coke oven operation in which a set furnace temperature pattern of a combustion chamber in a carbonization process is predetermined based on the operating conditions and charging specifications of the coke oven. A mathematical model that quantitatively expresses the average furnace temperature value and kiln exit temperature from charging to the target fire-off time is determined in advance, and the coefficients of the mathematical model are learned from the furnace operation results at the end of the current carbonization process. Using the mathematical model, calculate the correction gain for the set furnace temperature pattern of the combustion chamber based on the current operation results and the next charging specifications, and use the correction gain to calculate the setting used for the current carbonization process. Correct the furnace temperature pattern,
This is a method for controlling the fire-off time and exit temperature of a coke oven, characterized in that the amount of heat supplied in the next carbonization step is controlled in accordance with the corrected set oven temperature pattern.

The present invention will be explained in detail below. FIG. 1 is a diagram showing an example of a control configuration diagram of a coke oven fire-off time and outlet temperature control system according to the present invention. For each change in operating conditions such as carbonization time, fire-off time, and kiln exit temperature, the set furnace temperature or heating pattern is set for each stage of the carbonization process based on charging specifications such as operating coal amount and moisture content, and operating conditions. It is determined in relation to the amount of heat consumed, and this is set as the initial setting furnace temperature pattern in the supply fuel amount control system to control the amount of supplied heat. The method of determining this initial setting furnace temperature pattern is described in the above-mentioned Japanese Patent Application Publication No.
The method described in No. 59-20379 can be used. FIG. 2 is a diagram showing an example of the set furnace temperature pattern. In the figure, θ _f,t is the set furnace temperature value at time t, and a line connecting these θ _f,t shows the set furnace temperature pattern. Or the average furnace temperature value during the time from coal charging to the target fire-off time (target fire-off time T _H,R ), θ _f,E is the target furnace temperature uniform in the furnace width direction (θ _CE,R )
The final constant furnace temperature value θ _f,E is usually given a value close to the target kiln exit temperature θ _CE,R .

Here, the technical meaning of the average furnace temperature value _f will be explained. The total amount of heat that should be given to the coal charged in the charcoal chamber of the coke oven before it reaches the fire pit is determined by charging specifications such as the amount of coal charged and its moisture content. . The amount of fuel to be given to the coal is then supplied from the combustion chamber to the carbonization chamber by heat transfer. Therefore, an amount of fuel is supplied to the combustion chamber corresponding to an amount of heat that is proportional to the total amount of heat that should be given to the coal. Here, in the conventional constant fuel flow heating method, the fuel flow rate is kept constant throughout the period from charging to fire-off, and the fuel flow rate is changed within the period to maintain a constant fuel flow rate pattern (set furnace temperature pattern). This is the programmed heating method.

As can be seen from these facts, the average furnace temperature value _f shown in Figure 2 is a value proportional to the total amount of heat that should be given to the coal during the time from charging to fire-off (this is called fire-off time). This value _f is determined by the charging specifications and fire-off time. Further, the target kiln discharge temperature θ _CE,R is the coke temperature at the end of carbonization (during coke extrusion) necessary to obtain the desired coke quality, and this temperature also depends on charging specifications and fire-off time.

Now, in the present invention, each mathematical model _{f =} a・P+ _b・T _H +c ……( 1) θ _CE = d・P+e・T _H +f ...(2) is determined in advance. Here, the vector P is the charging specifications such as the amount of charged coal and its moisture content, T _H is the fire-off time,
Vectors a, d, b, c, e, and f are model coefficients, and these model coefficients are obtained by learning from the actual furnace operation at the end of the carbonization process by applying, for example, a sequential regression analysis method. Then, the next kiln exit temperature θ _CE is calculated as θ^ _CE ( k)=θ _CE (k-1)+d{P(k)-P(k-1)
} +e{T _H,R −T _H (k-1)} ...(3) and then estimate the next set furnace temperature pattern _f (k), θ _f,E (k)
(K)= _f (k-1)+a{P(k)-P(k-1)} +b{T _H,R −T _H (k-1)} ...(4) θ _f,e ( k) = θ _f,E (k-1) + θ _CE,R −θ^ _CE (k)……(5) In order to correct the current set furnace temperature pattern and determine the next set furnace temperature pattern. Correction gain α
α=θ/− _f (K)−θ _f,E (k)/θ _f (k−1)−θ _f,E (
K-1) ......(6). Then, using this correction gain α, the next (kth) set furnace temperature pattern θ _f,t (k) is determined as follows.

θ _f,t (k)=α{θ _f,t (k−1)−θ _f,E (k−1)} +θ _f,E (k) ……(7) Above θ _f,t (k) The amount of heat to be supplied is controlled using this as the set furnace temperature pattern for the next (kth) carbonization process. Here, as shown in FIG. 2, θ _f,t refers to the set furnace temperature value at each time from the end of charging to extrusion (specifically, at each time in each sampling cycle of supply heat amount control).

(Effects of the Invention) Figures 3a and 3b show a series of results of operations carried out according to the present invention as described above. FIG. 3a shows the deviation of the fire-off time from the target, and FIG. 3b shows the deviation of the kiln exit temperature from the target. As is clear from the figure, when the set furnace temperature pattern is corrected using the method of the present invention (solid line A), the deviation from the target is about 1/4 smaller than when using the conventional method (dotted line B). It's summery.

As described above, in a coke oven operation in which a set furnace temperature pattern of the combustion chamber is predetermined and operated, the method of the present invention is based on the current operating results and the next charging specifications. Since the pattern is corrected and this is repeated for each carbonization step, there is an excellent effect that extremely stable coke oven operation can be obtained as shown in FIG. 3.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one line of a control configuration diagram of a control system for fire-off time and outlet temperature of a coke oven according to the present invention, and FIG. 2 is a diagram showing an example of a set oven temperature pattern of a coke oven. , Figures 3a and b show one of the effects of the present invention.
It is a figure which shows an example.

Claims (1)

[Claims] 1. In a coke oven operation in which a set furnace temperature pattern of a combustion chamber in a carbonization process is predetermined based on operating conditions and charging specifications of the coke oven, charging specifications and fire-off time A mathematical model that quantitatively expresses the average furnace temperature value and kiln exit temperature from charging to the target fire-off time is determined in advance using Learn from the actual results, use the mathematical model to calculate the correction gain for the set furnace temperature pattern of the combustion chamber based on the current operation results and the next charging specifications, and use the correction gain to calculate the correction gain for the current carbonization process. Control of fire-off time and oven temperature of a coke oven, characterized in that the set furnace temperature pattern used in the above is corrected, and the fuel supply for the next carbonization process is controlled in accordance with the corrected set furnace temperature pattern. Method.