KR20020096582A - method for controlling electric power of integrated iron and steel plant - Google Patents

Abstract

PURPOSE: A method for controlling the power of an iron manufacture plant is provided to control power within the predetermined maximum power demand by selectively cutting off the power supplied to an electric furnace of a melting furnace and to minimize the thermal loss due to power cut-off by continuing the work of an electric furnace of a smelting furnace. CONSTITUTION: A method for controlling the power of an iron manufacture plant comprises the steps of setting up the total electric power of respective electric furnaces and integrating the total electric power by measuring the power supplied to the electric furnaces for a specific time(S1), searching if the mode of the electric furnaces is a load-limit mode(S2), comparing the integrated total electric power with the predetermined total electric power of entire iron manufacture plants if the electric furnaces are not in the load-limit mode(S3), and cutting off the power supplied to the electric furnaces gradually if the integrated total electric power is more than the predetermined total electric power of the entire plants or the same(S4).

Description

Method for controlling electric power of integrated iron and steel plant}

The present invention relates to an iron making plant, and more particularly, to a power control method of an iron making plant.

The steel plant uses electricity by signing a basic supply contract for industrial power, such as KEPCO and the maximum demand power, and the maximum demand power due to the increase in the maximum demand power (total 15 minutes) increases. (I) to be used with restrictions.

The steel plant is prioritized for suppressing the load of the first to nth electric furnaces (not shown) in the first to nth loads of the first to nth steel mills according to the conclusion of the basic supply contract for industrial power with KEPCO as described above. The predetermined total power amount Kwh1-s, Kwh2 which is a target value of the total integrated power amounts Kwh1-m, Kwh2-m, ..., Kwhn-m in the first to nth electric furnaces in the first to nth loads -s,… Kwhn-s) The priority is set by dividing the first to nth electric furnaces in the first to nth loads step by step according to the steelmaking capacity.

The operation process of the first to nth steel mills of the steelmaking plant is generally charged with a raw material into the first to nth electric furnaces in the first to nth loads, and then a high current is applied to the electrodes installed therein. The raw material is dissolved by the thermal energy generated at this time. Here, when scrap metal is first charged into an electric furnace of a steel mill to dissolve the scrap metal in the first melting (power supply) and almost melts in the first melting, the second scrap is charged and melted again, and the third charged scrap is third. After melting from melting and all the scrap metal turns into liquid, it is called refining machine from then on. The initial temperature of refining is about 1520 ℃, and at the end of refining, the temperature is about 1580 ℃.

In this case, the control unit measures the power amount of the first to nth electric furnaces only after the total power of the total power amount integrating unit exceeds the set total power of the entire steel mill and then measures the total power amount of each of the first to nth electric furnaces ( Kwh1-m, Kwh2-m, ..., Kwhn-m) and the set total power amounts (Kwh1-s, Kwh2-s, ..., Kwhn-s).

When the comparison result is that any one or more of the measured total power (Kwh1-m, Kwh2-m, ..., Kwhn-m) exceeds the set total power (Kwh1-s, Kwh2-s, ..., Kwhn-s) The controller determines the electric furnace in the load that exceeds the set total power amount (Kwh1-s, Kwh2-s,…, Kwhn-s) as the electric furnace of the refiner, and excludes the electric furnace of the refinery in the load according to the preset priority. The power is controlled so that the total power amount (Kwhn-m) measured below the set total power amount (Kwhn-s) of the entire steel mill is cut by cutting off the power supplied to the electric furnace of the remaining melter in the load. The measured total power amount Kwhn-m is reset after the first charge operation is completed, and the total power amount of the total power amount integration unit is reset to zero in units of 15 minutes.

However, the power control method of the steelmaking plant according to the prior art according to the priorities unconditionally regardless of the state of the electric furnace, that is, whether the melting furnace or refinery electric furnace if the total power of the total power amount integration unit exceeds the maximum demand power When the power supplied to the refiner's electric furnace is cut off, the high temperature molten steel of 1520 ~ 1580 ℃ in the refiner's electric furnace is not heated and the temperature of the molten steel decreases rapidly due to the difference with the ambient temperature. When re-working by re-powering the electric furnace with the power cut off, since a lot of energy is input, the cost increases.

Therefore, the present invention has been made to solve the above problems, when the integrated value of the power supplied to the entire first to n-th steel mill in the steel plant exceeds the total set power of the entire first to n-th steel mill. In order to provide a power control method of the steelmaking plant to selectively cut off the power supplied to the furnace in the melting furnace in accordance with the operation of the furnace, continue to operate the furnace of the refinery to control the power within the predetermined maximum demand power. There is this.

1 is a view showing an example of the system configuration of a steel mill to which the present invention is applied

2 is a flow chart of the power control method of the steelmaking plant according to the present invention

Explanation of symbols for main parts of the drawings

11a to 11n: 1st to nth load 12: control part

13: power cutoff control unit 14a-14n: first to nth power cutoff unit

15: n + 1 power cut-off unit 16a to 16n: transformer unit for first to nth furnaces

17: n-th power amount integration unit 18a to 18n: first to n-th power amount integration unit

Features of the power control method of the steelmaking plant according to the present invention for achieving the above object, (a) the total power of the entire first to n-th steel mill, and the first to the first to n-th steel mill setting the total amount of power in each of the n electric furnaces, and integrating the total amount of power by measuring the power supplied to the first to nth electric furnaces for a predetermined time; and (b) the mode state of the first to nth electric furnaces; (C) comparing the accumulated total power amount and the set total power amounts of the entire first to nth steel mills if the load is not the load limiting mode as a result of the search in step (b); (d) If the integrated total power amount is less than the set total power amount of the first to nth steel mills as a result of the comparison in the step (c), repeating the step (b), the integrated total power amount is the first to nth Total power set in the entire steel mill If greater than or equal to, interrupting power supplied to the first to nth electric furnaces in the first to nth loads step by step according to a predetermined breaking priority; and (e) load of the search result in step (b). In the limited mode, comparing the integrated total power amount with the set total power amount of the entire first to nth steel mills, and (f) the total integrated power amount of the first to nth steel mills as a result of the comparison in step (e). Repeat step (b) if less than the set total power of, and if the integrated total power is greater than or equal to the set total power of the entire first to n-th steel mill, the first to n-th electric load within the first to n-th load Comparing the integrated total power amount and the set total power of each of (i) and (i) determine the operating conditions of each of the first to n-th electric furnace in the first to n-th load according to the comparison result in step (g) First to nth loads And selectively disconnecting power supplied to the nth electric furnace.

The set total power of the entire first to nth steel mills is 98% or 99% of the maximum demand power in a 15-minute period, and the first to nth electric loads in the first to nth loads of the first to nth steel mills. As a result, each set total power amount is set to 75% of the first charge power amount.

Step (i) is determined as (i1) the electric furnace of the melter if the integrated total power amount is less than each set total power amount of each of the first to nth electric furnaces in the first to nth loads as a result of the comparison in (h). By repeating steps (e) and (f) after cutting off the power supplied to the corresponding electric furnace, and (i2) the integrated total power amount in the first to nth loads as a result of the comparison in step (h). If it is greater than or equal to each set total power of the first to n-th electric furnace, it is another feature that it comprises the step of determining the electric furnace of the refiner and repeating steps (e) and (f).

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Hereinafter, a preferred embodiment of the power control method of the steelmaking plant according to the present invention will be described.

1 is a view showing an embodiment of a system configuration of a steel mill to which the present invention is applied, wherein the first to nth loads 11a to 11n, the control unit 12, the power cutoff control unit 13, 1st to nth power interrupter 14a-14n, nth + 1 power interrupter 15, 1st to nth voltage transformer 16a-16n, and nth + 1 power amount accumulator 17 ) And first to nth power amount integration units 18a to 18n.

The first to nth loads 11a to 11n each include an electric furnace (unsigned) and an electrode (unsigned).

The controller 12 controls the amount of power consumed by the first to nth loads 11a to 11n.

The power cutoff control unit 13 outputs a control signal for cutting off the power supplied through the first to nth power cutoff units 15a to 15n according to the control signal of the control unit 12.

The first to nth power cutoff units 14a to 14n respectively cut off the power supplied to the first to nth loads 11a to 11n according to the power cutoff control signal output from the power cutoff control unit 13. Done.

The n + 1 power cutoff unit 15 cuts off the power supplied to the first to nth power cutoff units 14a to 14n when the power supplied from the lead wire is overloaded.

The first to n-th transformers 16a to 16n convert the power supplied through the first to nth power cutoff units 14a to 14n into a set power source, respectively, so that the first to nth loads 11a to. 11n).

The n + 1th power amount integrating unit 17 is transformed in the first to nth transformers 12a to 12n, respectively, and integrates the total amount of power consumed by the first to nth loads 11a to 11n, respectively. Will print.

The first to nth power amount integrators 18a to 18n are respectively transformed by the first to nth transformer transformers 12a to 12n and consumed by the first to nth loads 11a to 11n, respectively. Each is accumulated and output.

2 is a flow chart of the power control method of the steelmaking plant according to the present invention.

Referring to the accompanying drawings, the electric power control method of the steelmaking plant configured as described above is as follows.

The steel plant uses electricity by signing a basic supply contract for industrial power, such as KEPCO and the maximum demand power, and the maximum demand power due to the increase in the maximum demand power (total 15 minutes) increases. (I) to be used with restrictions.

Therefore, according to the conclusion of the basic supply contract for industrial power with KEPCO, the steel plant is set to be 98% or 99% of the maximum demand power in 15-minute cycles. The set total power amount of each of the first to nth electric furnaces in the first to nth loads of the n steel mill is set to 75% of the first charge power amount.

In this state, when power is supplied through the power line to generate an electric arc ARC according to the supplied power from the electrodes in the first to nth loads 11a to 11n, the first to nth loads 11a to In 11n), the furnace is operated to dissolve the charged scrap and the subsidiary materials, remove impurities and then tap the steel (S1). The first to nth loads 11a to 11n each include an electric furnace (unsigned) and an electrode (unsigned).

That is, the first to n-th transformers 16a to 16n respectively use power supplied through the n + 1 power cutoff unit 15 and the first to nth power cutoff units 14a to 14n as the set power. The transformer is supplied to the first to nth loads 11a to 11n, respectively. Then, the electrodes in the first to nth loads 11a to 11n generate an electric arc (ARC) in accordance with the supplied power to dissolve the scrap metal and secondary raw materials charged in the electric furnace. Here, in the electric furnaces in the first to nth loads 11a to 11n, the first charged scrap metal is first melted according to the electric arc (ARC) generated at the electrode, and when the scrap iron is almost dissolved, the second charged scrap iron is dissolved. When the second melt and the scrap iron is almost dissolved, the third charged scrap iron is melted and then refined to remove impurities contained in the molten liquid, followed by tapping. The first to third melt electric furnaces are melted. When the first to third charged scrap is turned into a liquid through the first to third melting, it is called the electric furnace of the refiner, the initial temperature of the refiner is about 1520 ℃, The temperature at the time of tapping is about 1580 ℃.

At this time, the n + 1 power amount integrating unit 17 is a power amount of the power consumed by the first to n-th load (11a to 11n), respectively, the power is transformed in the first to n-th transformer (16a to 16n) The total amount is accumulated and output.

In addition, the first to nth power amount integrating units 18a to 18n may be configured to consume power from the first to nth loads 11a to 11n, respectively, of which power is transformed in the first to nth transformer transformers 12a to 12n. The total amount of power is integrated and output.

Then, the control unit 12 receives the integrated total power output from the n + 1 power integration unit 17 and the integrated power output from the first to nth power integration units 18a to 18n and then determines whether the load is in the load limiting mode. Search for (S2).

When the search result is not the load limiting mode, the control unit 12 compares the total integrated power output from the n + 1 electric power integrating unit 17 with the total set power of the entire first to nth steelworks (S3). ). The total set amount of power of the entire first to nth steel mills is 98% or 99% of the maximum demand power over a 15 minute period.

As a result of the comparison, if the accumulated total power amount is smaller than the set total power amount of the entire first to nth steel mills, the control unit 12 repeats the step S2.

In addition, if the integrated total power amount is greater than or equal to the set total power amount of the entire first to nth steel mills, the control unit 12 sequentially supplies power to the first to nth electric furnaces according to a predetermined blocking priority. Block and repeat the step S2 (S4).

In addition, in the load limiting mode as a result of the search in step S2, the control unit 12 may calculate the accumulated total power output from the n + 1th power integration unit 17 and the set total power amounts of the entire first to nth steel mills. The comparison is made (S5).

As a result of the comparison in the step S5, if the accumulated total power amount is smaller than the set total power amount of the entire first to nth steel mills, the control unit 12 repeats the step S2.

In addition, if the integrated total power amount is greater than or equal to the set total power amount of the first to nth steel mills as a result of the comparison in step S5, the control unit 12 may include the first to nth power amount integrating units 18a to 18n. The integrated total power amount and the set total power amount of each of the output first to nth loads 11a to 11n are compared (S6).

As a result of the comparison in step S6, the integrated total power amount of any one or more of the first to nth loads 11a to 11n is greater than or equal to the set total power amount of each of the first to nth loads 11a to 11n. The surface control unit 12 determines the load as an electric furnace of the refiner and continues to supply power to the electric furnace (S8). That is, if the integrated total power amount is greater than or equal to the set total power amount of each of the first to nth loads 11a to 11n, the controller 12 determines that the refiner is an electric furnace and supplies power to the electric furnace. It will be continued, and repeat the step S5 (S7). The set total power amount of each of the first to nth loads 11a to 11n is 75% of the first charge power amount.

In addition, as a result of the comparison in step S6, the integrated total power amount of any one or more of the first to nth loads 11a to 11n is smaller than the set total power amount of each of the first to nth loads 11a to 11n. The multi-sided control unit 12 determines the electric furnace of the dissolver and outputs a control signal for cutting off the power supplied to the electric furnace (S8). That is, the controller 12 determines that the load is the electric furnace of the melter and supplies it to the electric furnace if the integrated total power amount is smaller than the set total power amount of each of the first to nth loads 11a to 11n as a result of the comparison in step S6. It outputs a control signal to cut off the power supply.

Accordingly, the power cutoff control unit 13 outputs a control signal for cutting off the power supplied to the electric furnace of the load through the power cutoff unit according to the control signal of the control unit 12.

Then, the power cut-off unit cuts the power supplied to the electric furnace of the load according to the power cut-off control signal of the power cut-off control unit 13 and repeats the step S5 (S9).

As described above, the power control method of the steelmaking plant according to the present invention has the following effects.

First, when the accumulated total power of the electric power supplied to the entire first to nth steel mills in the steel plant exceeds the set total power of the entire first to nth steel mills, it is supplied to the electric furnace of the melter according to the operation of the electric furnace. By selectively shutting off the power, the power can be controlled within a predetermined maximum demand power.

Second, when the accumulated total power of the power supplied to the entire first to nth steel mills in the steel plant exceeds the set total power of the entire first to nth steel mills, it is supplied to the electric furnace of the melter according to the operation of the electric furnace. By selectively shutting off only the power and continuing the operation of the refiner's electric furnace, the cost can be reduced by minimizing the heat loss caused by the power interruption.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims and their equivalents.

Claims (3)

(a) setting the total power amount of the entire first to nth steel mills and the first to nth electric furnaces in the first to nth steel mills, and supplying power to the first to nth electric furnaces. Measuring for a predetermined time and integrating each total amount of power; (b) searching whether the mode state of the first to nth electric furnace is a load limiting mode; (c) comparing the integrated total power amount with the set total power amount of the entire first to nth steel mills if the search result in step (b) is not the load limiting mode; (d) If the integrated total power amount is less than the set total power amount of the entire first to nth steel mills as a result of the comparison in the step (c), repeat the step (b), and the integrated total power amount is the first to nth steel Disconnecting power supplied to the first to nth electric furnaces in the first to nth loads step by step according to a predetermined interruption priority level if greater than or equal to a set total power amount of the entire factory; (e) comparing the integrated total power amount with the set total power amount of the entire first to nth steel mills in the load limiting mode as a result of the search in step (b); (f) If the integrated total power amount is less than the set total power amount of the entire first to nth steel mills as a result of the comparison in the step (e), the step (b) is repeated and the total integrated power amount is the first to nth steel Comparing the integrated total power amount and the set total power amount of the first to nth electric furnaces in the first to nth loads if the total power amount is equal to or greater than the total set power of the entire factory; (i) determining the operating conditions of each of the first to nth electric furnaces in the first to nth loads and supplying the first to nth electric furnaces in the first to nth loads according to the comparison result in step (g). And selectively shutting off the power supply. The method of claim 1, The set total power of the entire first to nth steel mills is 98% or 99% of the maximum demand power in a 15-minute period, and the first to nth electric loads in the first to nth loads of the first to nth steel mills. The total power amount of each furnace is set to 75% of the first charge (charge) power control method of the steelmaking plant, characterized in that each. The method of claim 1, Step (i) is (i1) If the integrated total power amount is less than each set total power amount of each of the first to nth electric furnaces in the first to nth loads, it is determined that the melting power is supplied to the electric furnace of the melter. Repeating steps (e) and (f) after shutting off the power; (i2) If the integrated total power amount is greater than or equal to each set total power amount of each of the first to nth electric furnaces in the first to nth loads, it is determined as an electric furnace of the refiner; , (f) repeating the steps of the power control method of the steelmaking plant, characterized in that it comprises a step.