JPH0765045B2 - Combustion control device for coke oven - Google Patents

Description

TECHNICAL FIELD The present invention relates to a combustion control device for individual carbonization chambers (kilns) of a coke oven.

[Prior Art] Conventionally, a target flue temperature (determined by the operating rate of the coke oven) in order to eliminate variations in the burn-down time of individual carbonization chambers.
Based on the deviation between the measured actual flue temperature and the deviation between the target burn-down temperature and the actual burn-down temperature, the heat supply amount and air amount of each carbonization chamber are set. The waist valve was adjusted manually.

[Problems of the prior art] However, this method only corrects the characteristic changes of the individual carbonization chambers for a long period of time, and cannot perform real-time follow-up control with respect to changes in the operating rate and charging specifications.

In order to quickly respond to changes in the operating rate and charging specifications, set the target flue temperature based on the operating rate and charging specifications, and make sure that the target flue temperature matches the actual flue temperature. ) And the waist valve (air amount) are considered. However, it takes time to perform the balf operation manually, and it is necessary to work in the basement of the coke oven that may cause gas leaks.
It can be performed only about 2 times, and it is difficult to reduce the variation in the fire fall time.

INDUSTRIAL APPLICABILITY The present invention performs real-time follow-up control of changes in operating rate and charging specifications, matches the actual flue temperature with the target flue temperature, reduces variations in the burndown time, and saves energy and stabilizes and improves coke quality. It is an object of the present invention to provide a combustion control device for a coke oven that can achieve the above.

[Means for Solving Problems] The present invention provides a combustion control device for a coke oven in which each furnace group constitutes a combustion chamber on both sides of a plurality of carbonization chambers, and a flue thermometer is installed in the wall of the combustion chamber, Elapsed time since coal charging
t _i, the furnace group target fire落時between NCT0, furnace group target standing time between ST0, instrumentation Nyusumi amount C _i, reads Sonyusumi water content TM _i, target flues temperature Qf _i of the coking chamber units based on these values From the target flue temperatures Qf _i and Qf _{i + 1} of the carbonization chambers on both sides of the combustion chamber, the target flue temperature Qf _j = 1/2 (Qf _i + Q
It is provided for each furnace group that calculates f _{i + 1} ) and calculates the opening adjustment amount of the gas cock and waist valve of each carbonization chamber from the deviation value between this target temperature and the flue temperature signal measured by the flue thermometer. The operation circuit and the opening setter provided for each furnace group that emits a predetermined amount of pulse signal based on the signal from the operation circuit, and the opening adjustment of the gas cock and waist valve based on the signal from this setting machine. Gas cock,
It is a combustion control device for a coke oven, which comprises an opening adjuster provided for each waist valve.

[Detailed Description of the Invention] FIG. 1 shows a schematic configuration of a coke oven. Each coke oven group is composed of a plurality of carbonization chambers 11.
Combustion chambers 12 are formed on both sides of 11. Fuel gas is supplied to the combustion chamber 12 through a distribution pipe 13, and the combustion heat of the fuel gas cokes the coal in the carbonization chamber 11. The exhaust gas after combustion is discharged from the exhaust pipe 14. A gas cock 15 is attached to each distribution pipe 13, and a waste valve is attached to each exhaust pipe 14.
16 are attached, and each is designed to adjust the gas flow rate. The combustion chamber 12 is divided into a plurality (for example, 32) of combustion small chambers 12a, 12b ... As shown in FIG.
And the flue thermometer 17 is installed in the wall. In this coke oven, combustion switching (switching between even-numbered and odd-numbered furnace groups) is performed in units of 20 to 40 minutes.

FIG. 3 is a block diagram showing the control device of the present invention.
This control device includes an arithmetic circuit 21 provided for each furnace group, an opening setting device 22, a gas cock, and opening adjustment devices 23, 24 provided for each waist valve. The arithmetic circuit 21 (calculator) calculates the deviation between the target flue temperature and the measured flue temperature. The target flue temperature and the operating rate (reactor group target burndown time NCT0, furnace group target placement time ST0, etc.) and charging specifications (determined by charging coal amount Ci, charging coal moisture amount TCi, etc.) It is set by the elapsed time ti after charging. The measured flue temperature is the measured value θfmj obtained from the flue thermometer 17.
Is. Then, the opening of the gas cock 15 and the opening of the waist valve 16 of each carbonization chamber 11 is calculated from the deviation value, and these calculated values ΔBj and ΔWj are output to the opening setter 22. In the opening setting device 22, the opening / closing signals (pulse signals) are sent to the opening adjusting devices 23 and 24 until the measured flue temperature reaches the target flue temperature.
To send. The opening degree setter 22 has functions of upper / lower limit check and time monitoring, and has a function of transmitting the present opening degrees Bj and Wj to the arithmetic circuit 21. Each of the opening adjusters 23 and 24 has a function of opening and closing one step at a time according to the opening / closing signal and returning the current opening values Bj and Wj to the opening setter 22 by analog signals. Each device constituting the control device of the present invention will be described in detail below.

FIG. 4 shows calculation procedures (1) to (6) in the arithmetic circuit.

(1) When charging coal, read the charging amount, the charging coal moisture value TMi, and the charging time.

(2) Calculate the target flue temperature θfi for each carbonization chamber based on the elapsed time ti after charging and NCT0, ST0, Ci, TMi.

(3) Calculate the target flue temperature Qfj in flue units.

(4) Calculate the flue temperature deviation based on the target flue temperature and the measured flue temperature Qfmj.

(5) Calculate the gas flow rate adjustment amount ΔFj from the deviation (Δθfj, t-1) at the previous adjustment and the constants K ₁ and K ₂ determined by the time constant of the coke oven.

(6) Calculate the opening adjustment amount of the gas cock and waist valve based on the gas flow rate adjustment amount and the current gas cock and waist valve opening and distribution pipe pressure.

In the arithmetic circuit 21, the above calculation is performed every predetermined time, for example
It is performed every 30 minutes, and the calculation result is transmitted to the opening setter and the setting result is received from the opening setter and reflected in the next calculation.

FIG. 5 shows a flow chart of the opening degree setting device 22. Here, as described above, ΔBj and ΔWj for each coking chamber are received from the arithmetic circuit 21, and Bj and Wj are transmitted. When the setting is abnormal, the number of the abnormal cock is also sent. The opening setter 22 calculates the number of opening / closing pulses, checks the upper / lower limit amount of the number of pulses, and checks the set time, and further transmits the opening / closing pulse for each opening setter.

FIG. 6 shows the relationship between the opening setting device 22 and the opening adjusting device 23 or 24. This opening degree regulator has a sequence 31 built therein, and rotates the drive motor 32 forward or backward by an open or closed contact. It also has a built-in upper / lower limit switch.

Opening correction amount, opening / closing pulse, opening value transmitted from each device,
An example of the adjustment result is shown in FIG.

Next, an example of implementing the device of the present invention will be described.

Calculation of carbonization average target flue temperature (θf _oi , i: kiln No) ... When coal is charged θf _oi ＝ KF _{j, n} ＋ 8106.6 (T _cj ＋ T _sj ) ＋0.93691 θ _ci ＋0.0
36147C _i · TM _i θ _cj = 460 + 440 τ _sj / τ _ci KF _{j, n} : It is called the constant term of the flue temperature. It is the difference between the target flue temperature and the actual flue temperature for each kiln and Calculate from the difference (this term automatically corrects deterioration of the flue thermometer and changes in kiln characteristics over time).

C _i : Charging amount (wet, ton / kiln) TM _i : Moisture content of charging coal (%) τ _ci ： Target burndown time (hr) τ _sj ： Target storage time (hr) _cj ： At core temperature of carbonization chamber average kiln unit target flues temperature from charging coal to kiln out (θf _oi, i: kiln No) calculations ... control timing for each _{θf oi = f oi + k {} g (θ c) -g (θ c)} g (θ _c ) = θ _ci + K2 / {(θ _ci ³ × 10 ⁻⁵ +150) × 10 ⁻³ } K2 = {(20−θ _cend ) · 10 ⁻³ } / {1 / (θ _cend ⁻³ × 10 ^-5
＋150） −1 / (20 ³ × 10 ^-5 ＋150)} ＝ 20 ＋ 880t / τ _ci (20 is the temperature of coal during charging, t: elapsed time after charging (h
r)) θ _cend = 900 + 880 τ _si / τ _ci (The value of θ _ci = t = τ _ci + τ _si ) is the coke temperature at the time of firing the kiln) (θ _c ) = 1 / (θ _cend −20) {1/2 ・θ _cend ² + 0.548k _o
(Y1 + y2) -200 + 0.363 k _o } k _o = 10 ³ k2 y1 = 1/2 (0.5825x1-0.4629) y2 = 1.732 (0.0543x2 + 1.1085) x2 ≤ 4.57 (θ _ci ≤ 850 ° C) = 1.732 (0.0376x2 + 1) .1848) x2 ≤ 4.57 (θ _ci > 850 ° C) x1 = (246.6 + θ _cend ) ² / (60811.6-246.6-θ _cend +
θ _cend ² ) x2 = {2 θ _cend −246.6} /427.1 where g (θ _c −g ( _c ): shows the average temperature transition of charging coal.

k: The transition of the average temperature of the charging coal is the degree detected by the installation of the flue thermometer, and in this example, it was set by actual measurement (the value of k is about 1/20) Target flue temperature (θf _oj ) Calculation of every control timing θf _oj = 1/2 (θf _oj + θf _{oj + 1} ) The temperature at the flue thermometer installation position is averaged on both sides because it is affected by the carbonization conditions of the carbonization chamber on both sides.

Automatic correction of the flue temperature constant term ... At the time of firing f _oki = F _{i, n} ＋ 8106.6 (T _cai ＋ T _sai ) ＋ θ _cai ＋0.036
147C _i · TM _{i cai} = 460 + 440T _sai / T _cai T _cai : Actual fire time (hr) T _sai : Actual set time (hr) f _oki : Average dry distillation target flue temperature calculated based on actual values θf _mj ＝ 1/2 {θf _mj / N _j + θf _{mj + 1} / N _{j + 1} } θf _mj : Actual flue temperature on the left side of the kiln, added value from charging to kiln removal, N _j : Actual flue temperature on the left side of the kiln The number of additions from the charging to the kiln removal _{θf mj + 1} : The added value from the charging of the actual flue temperature on the right side of the kiln to the kiln discharging, N _{j + 1} : From the charging of the actual flue temperature on the right side of the kiln to the kiln Number of additions up to kf _i = f _{i, n} − {f _oki −θf _mi } θf _oki −θf _mi : Flue thermometer in this carbonization cycle indicates the degree of change in kiln characteristics.

The _{f in + 1 = βf in +} (1-β) kf i (β = 0~1 exponential average constants) above control method, examining the kiln between the variation of the actual correction amount with respect to the required fuel gas flow rate correction amount of each kiln It was The error of the actual correction amount against the target correction amount is 20% or less,
This is about 1% in terms of the total amount of fuel gas supplied to the kiln. Therefore, it was confirmed that the fuel gas can be controlled with considerably high accuracy.

FIG. 9 shows the flue temperature transition before and after the kiln combustion control in the case of the control cycle 4H, and FIG. 10 shows the flue temperature transition before and after the kiln combustion control in the case of the control cycle 2H. In this embodiment, the change width of the supplied fuel is changed according to the control cycle to stabilize the control system. From this figure, it can be seen that the followability to the target flue temperature is excellent. The conventional system shows a transient response with a time constant of 5H in response to changes in the fuel gas flow rate, and the control system is not stable.

And conventional control (reactor group control on, kiln control off)
In comparison with the control of the embodiment, in the conventional control, when the individual flues are examined, the deviation between the target value and the actual value is 27
It was found that the temperature was as large as 7 ° C, but according to the example, it was significantly reduced to 7 ° C. Therefore, the control accuracy of the flue temperature is improved about 3 to 4 times as compared with the conventional one. As a result, as shown in FIG. 8 (control every 4 hours), the heat consumption was reduced (Δ10 kcal / kg-coal to 15 kcal / kg- compared to the conventional method.
coal) and reduction of coke strength variation (DI
It was 0.20) with a variation of 30.

[Advantages of the Invention] According to the present invention, the actual flue temperature and the target flue temperature are matched in real time, so that variations in the fire fall time can be reduced, and energy saving and stable and improved coke quality can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing the structure of a coke oven, FIG. 2 is an enlarged view of a main part of the coke oven, FIG. 3 is a block diagram showing an example of a control device according to the present invention, and FIG. 4 is an arithmetic circuit. Fig. 5 is a flow chart showing the calculation procedure of Fig. 5, Fig. 5 is a flow chart showing the calculation and control procedure of the opening setting device, Fig. 6 is an explanatory diagram showing the opening setting device and the opening adjusting device, and Fig. 7 is each device. FIG. 8 is a diagram showing an example of the output signal of FIG. 8, FIG. 8 is a diagram showing the control result by the method of the present invention in comparison with the conventional method, and FIGS. 9 and 10 are diagrams showing the flue temperature transition before and after the combustion control for each kiln. Is. 11 ... Carbonization chamber, 12 ... Combustion chamber, 13 ... Distribution pipe, 14 ... Exhaust pipe, 15 ... Gas cock, 16 ... Waist valve, 17 ...
… Flew thermometer, 21 …… Computational circuit, 22 …… Opening setting device, 23,24 …… Opening adjuster

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Kazutoshi Matsumoto, 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd. (56) Reference JP-A-57-159877 (JP, A) JP-A-SHO 60-31589 (JP, A)

Claims (1)

[Claims] 1. A combustion control device for a coke oven, wherein each furnace group comprises combustion chambers on both sides of a plurality of carbonization chambers, and a flue thermometer is installed in the wall of the combustion chamber. t _i, the furnace group target fire落時between NCT0, furnace group target standing time between ST0, instrumentation Nyusumi amount C _i, reads Sonyusumi water content TM _i, target flues temperature Qf _i of the coking chamber units based on these values = F (t _i , NCT
0, ST0, C _i , TM _i ) is calculated and the target flue temperature Qf _j = 1/2 (Qf _i + Qf in flue units is calculated from the target flue temperatures Qf _i and Qf _{i + 1} of the carbonization chambers on both sides of the combustion chamber. _{i + 1} ) is calculated, and the gas cock of each carbonization chamber and the opening adjustment amount of the waist valve are calculated from the deviation between this target temperature and the flue temperature signal measured by the flue thermometer. An arithmetic circuit, an opening setter provided for each furnace group that emits a predetermined amount of pulse signal based on the signal from the arithmetic circuit, and the opening of the gas cock and waist valve is adjusted based on the signal from this setter. A combustion control device for a coke oven, comprising a gas cock and an opening adjuster provided for each waist valve.