JPH02254115A - Method for controlling automatic distribution of converter gas - Google Patents

Abstract

PURPOSE:To miniaturize the equipment and to prevent loss of gas and lowering of power generating efficiency by controlling automatically distribution of converter gas for supplying into mixed gas producing equipment and power generating equipment together with blast furnace gas and coke oven gas according to the generating condition thereof. CONSTITUTION:By-product gases of the blast furnace 1, coke oven 2 and converter 3 are supplied into the power generating equipment 5 and the mixed gas producing equipment 6. Then, the generating condition of the above converter gas is assumed with a control system (computer) 9 based on informations in operational condition of the converter 3. From this generating condition and discharging condition, storing level in a converter gas holder 4c is assumed and the discharge of the converter gas is controlled within the range of the upper and lower limits thereof. Further, according to the storing level of holders 4a, 4b for blast furnace gas and coke oven gas, the discharge of the converter gas into the mixed gas producing equipment 6 is controlled. The quantity to be impossible to treat to this is supplied into the power generating equipment 5 and controlled. By this method, the distribution of the converter gas is controlled automatically and labor saving and miniaturization of the gas holder are obtd. and also the useless discharge of the by-product gas and the efficiency lowering of the power generating equipment, etc., are prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for automatically controlling the distribution of converter gas, and more specifically, the present invention relates to a method for automatically controlling the distribution of converter gas, and more specifically, at least the distribution of blast furnace gas by-produced in a blast furnace and by-produced in a coke oven. A mixed gas production facility O1 that produces a mixed gas by being supplied with cox oven gas and converter gas that can be used as an auxiliary gas in a converter, and a power generation facility that can absorb at least the converter gas. The present invention relates to an automatic converter gas distribution control method in a converter gas dispensing system in which converter gas subliminated in the converter is once stored in a converter gas holder as a buffer and then distributed and discharged.

[Conventional technology]

Conventionally, such converter gas distribution adjustment work was done by the operator based on the converter work plan (in other words, the predicted status of converter gas generation).
Process data such as the status of gas storage levels in each gas holder as a buffer for blast furnace gas, coke oven gas and converter gas, the amount of mixed gas produced by mixed gas production equipment, and the amount of each gas supplied to power generation equipment. The flow rate of converter gas to the mixed gas production equipment is determined visually from the CRT as a display device and instruments, taking into account the supply and demand balance of each gas, and keeping the gas storage level of each gas holder within the upper and lower limits. The converter gas flow rate to the power generation equipment was manually adjusted based on intuition and experience.

[Problems to be Solved by the Invention] However, with the manual adjustment method described in Section 2, converter gas is generated only intermittently during converter blowing, and the capacity of the holder as a gas storage buffer is limited. If the gas flow rate is small due to cost reasons, the gas flow rate is large compared to the holder capacity, so the holder cannot be used unless the gas is discharged from the holder with a certain degree of visibility or stored in preparation for demand. The gas storage level within the tank may exceed its upper and lower limits.

Furthermore, due to various circumstances during operation, the schedule for converter blowing is frequently changed, making it difficult to accurately predict converter gas generation. Changes should also have an impact on the gas storage levels of the blast furnace gas and coke oven gas holders connected to the equipment, so this must also be taken into consideration;
Additionally, there are constraints such as the need to keep the flow rate to the power plant as constant as possible to prevent a drop in operating efficiency, so the supply and demand balance for each gas must be adjusted in conjunction with these constraints. Must be.

In other words, in such a converter gas discharging system, a very large amount of information (converter operation plan, blowing results, gas storage level of each holder for blast furnace gas, coke oven gas, and converter gas, The total amount of converter gas to be discharged and its distribution are determined by making instantaneous judgments based on the trends in blast furnace gas, coke oven gas, mixed gas usage status, and predictions (1) of the load status of the power plant, etc. Not only is this necessary, but the method for determining it is also complicated, leading to the following problems.

(b) When there is a large amount of information to be used as a basis for judgment, and the capacity of the gas holder for gas storage is small due to cost considerations, the time available for making judgments is short, and Since the frequency is high, the burden placed on the operator is large.

(b) Since there are differences in the level of judgment depending on the operator,
Improper adjustment due to variations in the content of the judgment and errors can lead to loss (dissipation) of by-product gas or a decrease in efficiency due to an increase in the number of changes in the flow rate to the power plant.

The purpose of the present invention is to solve the above-mentioned problems, reduce the burden on the operator (and save labor), and prevent the gas storage level from exceeding the upper and lower limits even if the capacity of each gas holder is small. An object of the present invention is to provide an automatic distribution control method for converter gas that does not cause wasteful dissipation of gas or reduce the efficiency of power generation equipment.

[Means to solve the problem]

In order to achieve the second object, the present invention provides a mixed gas that is supplied with at least blast furnace gas by-produced in a blast furnace, coke oven gas by-produced in a coke oven, and converter gas by-produced in a converter. After once storing the converter gas by-produced in the converter in a converter gas holder as a buffer, We installed a computer to automatically control the distribution of converter gas in the system for distributing and discharging converter gas.

[Effect]

The computer is given information regarding the operation of the converter and predicts the generation status of converter gas by-produced from the converter,
The system predicts fluctuations in the gas storage level of the converter gas holder based on the predicted occurrence situation and the current converter gas dispensing situation,
Adjustment is made so that the predicted gas storage level of the converter gas holder does not exceed the predetermined lower limit of 1 L and the amount of converter gas to be discharged is maintained as constant as possible, and the converter gas is discharged to the power generation equipment. Assuming that the current amount is maintained, as a result of adjusting the amount of converter gas discharged to the mixed gas production equipment, the gas storage level of the blast furnace gas holder that supplies blast furnace gas to the mixed gas production equipment and the mixed gas production equipment It predicts how the gas storage level of the coke gas holder that supplies coke oven gas to the coke oven gas holder will fluctuate, and the mixed gas production equipment The amount of converter gas discharged to the mixed gas production equipment is adjusted so that the mixed gas discharged to the converter gas does not exceed the upper and lower mixing limits, and the amount of converter gas discharged from the converter gas holder is adjusted to The amount that cannot be handled by the amount of converter gas delivered to the mixed gas production equipment is adjusted by the amount of converter gas delivered to the power generation equipment.

This will be explained in some detail below.

First, the prediction of the blowing time of the converter is made based on the converter work plan and the schedule is revised based on the current blowing performance information to make it close to the actual situation. For example, if the blowing preparation signal is not received even just before the scheduled blowing start time, the blowing scheduled time is adjusted backward. Furthermore, if blowing actually starts at a completely unscheduled time, it is determined that unscheduled blowing has been performed, and the amount of converter gas generated is additionally taken into consideration. Alternatively, if blowing has started but gas recovery does not start, it is determined that blowing is not generating gas and the amount of converter gas generated is not reduced by the planned amount.

Next, based on the predicted converter gas collection time, the current gas storage level of the holder, and the gas discharge amount, the gas discharge amount is as constant as possible, and the gas storage level of the converter gas holder is within the allowable range. Calculate the amount. The basic idea is shown below.

Q in is the gas recovery amount, Q o u L is the gas discharge amount, and tI.

The gas storage level of the holder at a time, H,. 1
is the gas storage level of the holder at the next point in time, Il is the upper limit of the holder, I"'i+- is the lower limit level of the boulder, 11. is the current gas storage level of the boulder,
shall be. Then, approximately the following formula holds true.

From what we are trying to achieve, HL ≦ H2S HH HL ≦ Ho-to Σ (Qi, -0, ,,
) ≦ IllΣQ, 7 is given by the already predicted collection time, so Q is calculated. uL is, in other words, if the current holder gas storage level is set to H8 as the legal standard,
Hi = H, +Σ(0, i, , -Q, ut), and the gas is stored in the holder at i and the bell is within the upper and lower limits.
. Q is such that ++1 is constant (ΣQouL is a straight line) and the above equation is satisfied for as long as possible. Find ut.

The upper and lower limits at this time are variable values, and the physical upper and lower limits of the equipment are set to 2 to determine the current value. It is set by allowing a certain amount of margin depending on the amount of R combined gas used and the flow rate of converter gas to the power generation equipment. For example, if the flow rate of the power generation equipment is not zero, due to the characteristics of the boiler and turbine of the power generation equipment, the flow rate cannot be suddenly reduced to zero. The gas flowing to the equipment is cut off by the flow before it is turned on, ftQ. .

However, (IPS...Current flow rate t to power generation equipment
1...Change response time γ...Check the margin for the opening change rate of the flow rate control valve (add this amount to the physical lower limit of the equipment).

Next, the calculated gas payout amount is sent to the mixed gas production facility,
At this time, the converter gas flow rate destined for the power generation equipment will be maintained at the current level, and if the converter gas flow rate destined for the mixed gas production equipment is going to be increased or decreased from the current level. By looking at the gas storage levels in the blast furnace gas and coke oven gas holders and their trends, the flow rate of converter gas going to the mixed gas production facility, which is currently being adjusted, is The flow rate to the mixed gas production equipment is determined by determining whether the gas storage level of the holder is about 1 without deteriorating.

Furthermore, the flow rate after the change will be such that the calorific index of the mixed gas remains constant, taking into account the amount of mixed gas used at that time and the upper and lower limits of the flow rates of blast furnace gas and coke oven gas to the mixed gas production equipment. It will be checked whether the mixed gas content of the converter gas destined for the mixed gas production equipment is within the upper and lower limits determined by the above, and the amount exceeding the upper and lower limits will be dealt with by changing the flow rate to the power generation equipment.

(Example) FIG.
FIG. 1 is a block diagram showing a schematic configuration of the entire steelworks.

In the figure, 1 is a blast furnace that produces blast furnace gas as a by-product, 2 is a coke oven that produces coke gas as a by-product, 3 is a converter that produces converter gas as a by-product, 4a is a gas holder as a buffer for storing blast furnace gas, and 4b is a coke oven. A gas holder as a buffer for storing gas, 4c a gas holder as a buffer for storing converter gas, 5 blast furnace gas, coke oven gas,
Private power generation equipment that generates electricity by being supplied with converter gas,
6 is a mixed gas production facility that is supplied with blast furnace gas, coke oven gas, and converter gas to produce a mixed gas; 7 is a mixed gas production facility that uses blast furnace gas or coke oven gas as a single gas (in other words, as a single gas)
8 is a factory that is supplied with and uses lI gas, 9 is a control system (computer),
12 is another system, 103 to 10c are flow rate control valves for by-product gas supplied to private power generation equipment, respectively, lla to l.
lc is a flow rate control valve for the by-product gas supplied to the mixed gas production equipment.

As shown in Figure 1, in the iron and steel making and steel works, byproduct gases (blast furnace gas, coke oven gas, converter gas) are generated by the blast furnace 1, coke oven 2, and converter 3. Each gas is supplied to the factory 7, private power generation equipment 5, and mixed gas production equipment 6 via gas holders 4a, 4b, and 4c, which serve as a sofa for storing by-product gases and absorbing fluctuations. Further, the gas mixed in the mixed gas production facility 6 (nitrogen gas is also mixed as required) is supplied to the mixed gas usage factory 8. Mixed gas production equipment 6 performs mixing control so that a certain index (Wonhe index) and pressure are constant, and the amount of mixed gas used and the supply of converter gas are controlled by the blast furnace gas and coke oven gas. The amount mixed is controlled.

Here, the converter gas generated in the converter 3 includes information from other systems 12, that is, information such as the operation plan in the converter 3, the blowing '$ preparation signal, the blowing start signal, etc., and the converter gas, Information such as the gas storage level of each holder 4a to 4C for blast furnace gas and coke oven gas, the amount of mixed gas used in the factory 8, the amount of each gas going to the mixed gas production equipment 6, the amount of each gas going to the private power generation installation 5, etc. Based on this, calculations are performed in the control system 9, and the flow rate of the converter gas to be distributed to the private power generation stage wi5 and the mixed gas production equipment 6 is determined and automatically distributed.

In other words, the other systems 12 include a host computer that stores operation schedule information for the converter 3, and another computer that collects nearby operation information, performance information, etc. of the converter 3. These are shown collectively.

Figure 2 shows the control system (computer) in Figure 1.
FIG. 9 is an explanatory diagram showing a specific example of No. 9;

In FIG. 2, - Flow of converter information) shows the flow of the calculation procedure. First, various signal information F1 (Converter 3
), various field data F
3 (current flow rate of each gas supplied to the mixed gas production equipment 6 and private power generation equipment 5, current value of gas storage level of each gas holder, etc.) and converter operation plan information F2 (indicating the operation schedule of the converter) information, etc.) Also, converter operation plan information F2
Since there are many changes that occur during operations (for example, actual operating results are behind the plan, practical information), the operator records the changed plans as the latest operation information F4. input.

Next, in step S1, a blowing schedule in the converter 3 is predicted based on the various signal information F1, the converter operation plan information F2, and the nearby operation information F4.

Next, in step S2, in consideration of fluctuations in the gas storage level in the converter gas holder 4C, in order to prevent the gas storage level from exceeding the upper and lower limits of the level in the converter gas holder 4C for as long as possible, Calculate how much gas should be discharged from the furnace gas holder 4C.

Next, in step S3, the amount of converter gas LDG to be supplied to the mixed gas production equipment 6 is calculated based on the calculation result of step S2. Here, first, the amount of converter gas delivered to the mixed gas production equipment 6 is calculated, assuming that the current amount of converter gas delivered to the private power generation equipment 5 is maintained. Next, by determining the amount of converter gas LDG to be supplied to the mixed gas production equipment with respect to the amount of mixed gas used at that time, the amount of blast furnace gas BFG supplied from the blast furnace via the gas holder 4a, Various types of coke oven gas COG supplied from the coke oven 2 via the gas holder 4b are determined, and as a result, the gas storage level in both gas holders is discharged to the mixed gas production equipment 6 so as not to exceed the predetermined upper and lower limits. Find the converter gas amount. Furthermore, adjustment is made so that the upper and lower limits of the amount of mixed gas mixed in the converter that can be delivered to the mixed gas production equipment 6, determined by the amount of mixed gas used, etc., are not exceeded.

Next, in step S4, if there is an amount that cannot be handled by the amount of converter gas discharged from the converter gas holder 4c determined in step S2 and the amount of converter gas discharged to the mixed gas production equipment 6 determined in step S3, private power generation is performed. Set up! Adjust accordingly by changing the amount of converter gas discharged to a5.

After that, in step S5 of control and guidance,
Such flow rate adjustment amount is displayed on the display DISP2 for the operator's reference.

Further, a flow rate adjustment signal is sent to the control valve 11c in accordance with the flow rate adjustment amount of the converter gas LDG to be supplied to the mixed gas production equipment 6,
Converter gas L is supplied to the mixed gas production equipment 6 accordingly.
Adjust the flow rate of DG. Similarly, a flow rate adjustment signal is sent to the control valve 10C according to the flow rate adjustment amount of converter gas LDG to be supplied to the private power generation facility 5, and the private power generation facility (#
The flow rate of converter gas LDG supplied to 5 is adjusted.

〔Effect of the invention〕

According to this invention, the following effects can be expected.

(b) Automation centralizes work (operation), making it possible to prevent loss (dissipation) of byproduct gas due to poor adjustment and reduction in efficiency due to frequent changes in the flow rate to power generation equipment.

(b) It is possible to reduce costs by downsizing the gas holder as a gas storage facility (by reducing the holder capacity, it is possible to reduce the required loss I).

(c) Labor saving is possible through automation. In other words, monitoring of the order of steel tapping, which was previously performed by operators, monitoring of the status of blast furnace gas, coke oven gas, and converter gas holders, monitoring of mixed gas consumption, monitoring and operation of the amount of each gas going to power generation equipment,
Monitoring and operation of the converter gas flow rate to the mixed gas production equipment are automated, making it possible to save labor.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of iron making and steel production for explaining an embodiment of the present invention.
FIG. 2 is a block diagram showing a schematic configuration of the entire steelworks. FIG. 2 is an explanatory diagram showing a specific example of the control system 1 and (computer) 9 in FIG. 1. Explanation of symbols 1... Blast furnace, 2... Coke oven, 3. Converter, 4a4
b, 4c...Gas holder, 5...Private power generation equipment, 6
...Mixed gas production equipment, 7..Factory using single gas,
8... Factory using mixed gas, 9... Control system (computer), 10a to 10c... Flow rate control valve, 11
a-11c...flow control valve, 12...other systems. Agent: Patent Attorney Namiki Tsukio Agent: Patent Attorney Kiyoshi Matsuzaki■

Claims (1)

[Claims] 1) A mixed gas production facility for producing a mixed gas by being supplied with at least blast furnace gas by-produced in a blast furnace, coke oven gas by-produced in a coke oven, and converter gas by-produced in a converter; power generation equipment capable of absorbing the converter gas, and once the converter gas by-produced in the converter is stored in a converter gas holder as a buffer;
In a system for distributing and discharging converter gas, there is a stage in which information regarding the operation of the converter is given to predict the generation status of converter gas as a by-product from the converter, and the predicted generation status and current status. The step of predicting the fluctuation in the gas storage level of the converter gas holder from the converter gas dispensing status of adjusting the amount of converter gas to be kept as constant as possible, and assuming that the current amount of converter gas delivered to the power generation equipment is maintained, as a result of adjusting the amount of converter gas delivered to the mixed gas production equipment, predicting how the gas storage level of a blast furnace gas holder that supplies blast furnace gas to the mixed gas production equipment and the gas storage level of a coke gas holder that supplies coke oven gas to the mixed gas production equipment will change; Dispense to the mixed gas production equipment within a range in which the predicted gas storage level of both gas holders does not exceed predetermined upper and lower limits, and in such a manner that the mixed gas to be delivered to the mixed gas production equipment does not exceed the upper and lower mixing limits. adjusting the amount of converter gas to be delivered to the mixed gas production equipment, and sending an amount to the power generation equipment that cannot be handled by the amount of converter gas delivered to the mixed gas production equipment with respect to the total amount of converter gas delivered from the converter gas holder. A method for automatically controlling the distribution of converter gas, comprising the steps of adjusting the amount of converter gas discharged.