JPS59118817A - Method for controlling combustion in side burner firing continuous heating furnace - Google Patents

Abstract

PURPOSE:To harden the materials to be heated in respective zones to a uniformly hardened state by detecting quantitatively the hardened condition of the materials to be heated in a real time, and shutting off the burners at the part where there is the material which is hardened satisfactorily. CONSTITUTION:The surface temp. of a charged billet 34 is preliminarily corrected and calculated with an initial temp. correcting device 21 and is outputted to a temp. calculator 22. The temp. of the furnace is measured with thermometers 31 at zones A-E and the average temp. by each piece of the billets 34 arriving at a heating zone 35 are estimated in a real time. The estimated temps. are outputted to a heat quantity calculator 23 which determines the quantity of the heat to be supplied to attain the target temp. The quantity of the heat determined by a comparator 24 and the set quantity of heat are comparatively calculated, and the result thereof is outputted to a device 27 for determining the position to intercept burners. The largest quantity of heat is outputted to a temp. setter 40 which outputs the set furnace temp. to a controller 29. The positions at the zones A-E where the burners are to be intercepted are determined in the device 27 from the information of the number of the burners to be intercepted, the information of tracking in the furnace and the information of the hardened condition, and a command is emitted to a control device 28 which turns off the shutoff valves 37 of fuel branches.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion control method for baking steel slabs or cast slabs to a target extraction temperature without variation in a side burner continuous heating furnace.

FIG. 1 shows a schematic diagram of the heating furnace. A steel billet or piece (hereinafter referred to as a steel billet) 10 is transferred from a charging port to a heating furnace 8 by a charger 1.
1. The walking beam 4 drives the preheating zone 5 in the transport direction of the arrow. Heating zone 6° Soaking zone 7 and 1f (l) Heating zone 0. Soaking zone 70 is heated and soaked by side burner 3 installed on both side walls. The piece 10 is extracted from the extraction port by extractor 2, and sent to the pressing process.9
There is a partition wall in the valley.

In recent years, hot billet charging into the above-mentioned heating furnace has become possible by directly connecting continuous casting equipment to heating equipment, roller tables, or railways. For example, in the case of railway transportation, the temperature of the copper strips is different from the stacked position V because the lot is stacked on a freight car and transported, so the temperature of the copper strips varies depending on the temperature at which the electricity is charged to the heating furnace within the lot. In addition, there are cases where the billet temperature differs between lofts depending on the casting conditions, and billets with different temperatures within or between lots may be charged to the heating furnace in sequence. Occurs often. My father said that the operation of a heating plant is generally connected to steel billets.
t and inside the furnace at a constant pitch? l! It is called continuous operation, but due to the difference in production capacity between continuous cutting equipment and rolling equipment, it is possible to produce one or half a charge of steel billets per layer.
It often happens that batch operations are carried out, such as intermittently charging copper chips, or stopping the production of copper pieces in the furnace for one hour and waiting.

In this way, one heating furnace can perform continuous confectionery and batch operations.
In this case, the axial burner arrangement has the disadvantage of causing uneven heating of the copper pieces waiting in the furnace, so a side bar tool that can evenly heat the copper pieces waiting in the furnace is recommended. It is used.

Conventionally, combustion control methods in heating furnaces using side burners or heating furnaces using axial flow burners have been used to select the material to be heated that is in the worst baked state among the liquid heating materials existing in the valley zone at a predetermined time. The temperature inside each furnace was determined and controlled so that the temperature could be raised at a predetermined extraction temperature. With this method, since the furnace temperature 1 is determined by focusing on the material to be heated that is in the worst baked condition, a problem arises in that other materials to be heated are overcooked. In addition, from the point of view of energy conservation, a control force method is used in which burners are shut off in areas where the material to be heated is not present in order to prevent wasteful combustion. It wasn't enough.

Does the present invention solve the above-mentioned problems? 1il
As a precaution, we can monitor the heating condition of the Temporary 7JlI Heat Shrine in real time, and turn off the burner r in the part where the heated material is placed in a well-baked condition. It provides a method for uniformizing the baked state of materials, and its feature is that the furnace temperature control for heating the heating furnace, soaking zone, or both is subdivided into each burner zone, and the furnace temperature of each zone is adjusted. From this, estimate the average temperature for each heated material7, calculate the amount of heat required for the material to be heated to reach a predetermined extraction temperature at a predetermined time from the estimated temperature, and use the amount of heat to The rising state is calculated, and the position of the burner zone to be thinned out is determined based on the calculation result, tracking information in the furnace, and burner thinning number information, and the fuel cutoff valve of the burner zone to be thinned out is turned on/off according to the determined VC. However, the amount of heat supplied to the heated material is adjusted so that the heated material is baked to the target extraction temperature without variation.

Hereinafter, the present invention will be described in detail with reference to the figures.

Figure 2 shows Mei7ii! in the heating zone of the present invention! i ′f91
It is a block diagram which reads J clearly. In addition to installing the side burner 33, the heating zone 35 is also provided with combustion control zones from the extraction port 1 to the A-son to the E-horn.

The material to be heated 34 enters the E zone of the heating zone 35 from the preheating zone and is sequentially sent by a walking beam 36 in the transport direction indicated by the arrow. Meanwhile, the liquid heating charge 34 is applied to both side walls VC of each zone.
Heating can be completed with side burners 33 (each zone has 14 burners above and below the side walls of the picture). A cutoff valve 37 for turning on/off the supply of fuel gas for each valley zone is provided in the fuel branch pipe, and a fuel flow rate regulating valve 38 is provided in the fuel main pipe. The positioning needle 39 is installed at the position. Furthermore, there is a thermometer (not shown) to measure the initial surface temperature of the copper piece near V←Heating T. Also, between the burners in each zone of the heating zone, there is a temperature meter (not shown) to measure the furnace temperature. A plurality (2 to 3) are provided in the furnace width direction. In the vicinity of the thermometer 31 between the burners, a 1lflj official temperature wave; ing. It should be noted that the thermometer 31 and the control thermometer 32 may not be provided separately, but may be implemented using a single thermometer.

Next, the operation of the present invention based on such a configuration will be described.

First, the surface temperature of the copper piece is measured with a thermometer (not shown) at the inlet of the steel piece charged into the heating chamber. Therefore, the temperature of the steel billet estimated in advance for each part (15 points) of the surface of the wall of pot 1 shown in Fig. 3 is calculated using the two-dimensional heat-coil differential force equation for the cooling process from construction to charging. Calculation is performed to add correction, and the result is output to the liquid heating paulownia temperature calculation device 22 and held Iy.
5) The J heating charge is the thermometer 3 in the valley zone.
Measure the octopus temperature in step 1, input it to step 22, and add 4+ to the average temperature of the heated shrine in real time.

This thermal estimation calculation uses the two-dimensional heat differential force equation to calculate 15 points on the surface and internal valleys of the skid part A of the copper piece and the central part B between the skids as shown in Figure 3. The initial temperature corrected by I1. The average temperature of one heated material is estimated from ij and the furnace temperature. The estimated temperature is output to the calorific value calculation device 23, and based on the estimated temperature, all heated materials in each zone are supplied so that they reach a constant target temperature at a constant extraction time of 7Jt. The amount of heat q per hour [fm] is calculated.

Based on the estimated temperature, the amount of heat q per unit time to be supplied so that the total liquid heating charge in each zone reaches a predetermined target temperature at a predetermined extraction time is determined as follows.

TR is the average temperature of the temporarily heated material estimated by the two-dimensional heat conduction difference equation described above, and the temperature of the heated material is 1.

ratio N tray ρ・average temperature of the heated dog on the board +hLT! The specific heat at (OR1) The specific heat at the target temperature T and C
In the case of rice, the amount of heat ΔQ that must be supplied from the current time to the predetermined extraction time of the liquid heating material is calculated by the following equation.

Therefore, the heat ttq to be supplied per unit time is q=ΔQ/lR, where tH is the time from the current time to the extraction time. The larger this q is, the worse the lily condition is, and the smaller q is, the better the lily condition is.

The amount of heat q that can be calculated is the heat set by the comparator 25 'lT
It is compared and subtracted mutually with j' and q. Output No. 16 of this calculation result is input to the burner thinning position determining device 2-7 which determines the burner thinning position. On the other hand, the comparator 25 indicates that the largest q is the output power in the furnace, j and the foot device 40, and the calculation of the set furnace temperature is indicated at q. Please give me the calculation result to 29/
).

On the other hand, the burner thinning number setting device 26 inputs the current (1) flow shortness from the flow control group of 1.
The number of burners to be thinned out is determined from the relationship between the fuel consumption value and the number of ignited burners, and is output to the burner thinning positioning device gH27.

The solid line shown in Figure 4 indicates the number of burners required to ensure the combustion amount of the entire VC1 band when a certain fuel f- shown on the horizontal axis is flowing, and the number of burners below the solid line is So,
The required combustion level is 4i (J) The dotted line indicates the number of burners required to secure the required frame length, and if one burner above the dotted line is lit, This shows that the required frame length is not shortened.The diagonal line "range" indicates the range of the number of burners ignited per burner, and this number of ignitions is subtracted from the total number of burners in the belt, and the difference is the number of burners in the belt. The number of thinned out burners (the number of zones) is determined. In Fig. 4, the range of the number of thinned out burners (1m) differs depending on the type of burner.

Furthermore, the heating beam driving device 36 tracks the heated material (1) moving distance and the sliding force in the T, and the current constant force tracking device 24 calculates the result. is output to the burner thinning position determining device 27.

In 27, from the information on the number of burners to be thinned out in 26, the tracking information in 24, and the 10* report on the υ′ rising state of the heat source in 125, it was determined that the number of burners was thinned out. ′
Determine the thinning position of the zone by using the number of thinning burners in the zone where A is determined. Thin out.The decided thinning position is
28 burner thinning control device - 〇' command. 28 turns off the communication valve of the fuel branch pipe according to the command. The supply of heat to the material to be heated in the zone that has been turned off is stopped, and the overheating is adjusted.

1, the information for determining the 1i-il pull position of 2°A is 29
The control thermometer 32 is selected depending on the burner thinning level when the furnace temperature setting device is operated manually. In accordance with instructions from the furnace temperature control device 29, the control temperature switching device 3/32 thermometers for iron control are switched. This is because when the thinning position is changed, the furnace temperature in the burner zone will also change, and if a thermometer is used to control that area, it will try to control the low temperature area, causing combustion loss, so it will need to be switched. It is. Selected control thermometer 32
Actual furnace temperature Tm obtained from furnace temperature setting device 40
Deviation from the furnace set temperature ゛1゛s determined by △T=T
The opening of the fuel flow rate adjustment valve 38 of the fuel main pipe is adjusted by the furnace temperature control device 29 so that the fuel flow rate value is increased or decreased by e-Tm and the furnace temperature is maintained at the actually measured temperature Ts in the furnace.

This zone thinning control (Yo, thermometer 3 between the valleys)
1, the denominator VC furnace temperature is lowered, and the above calculation is repeated to determine the thinning position, and the fuel cutoff valve 37 of each zone is turned on/off and the opening degree of the fuel flow rate adjustment valve 3B is adjusted. At a predetermined extraction time, the supply of heat q is adjusted so that all of the heated materials are heated to a predetermined temperature δ one by one.

Next, an example of burner thinning control using the combustion control method of the present invention will be described.

51) 1(a) shows a case where a group of r1 copper pieces exists in zones A to D of the heating zone 35, and no steel pieces exist in zone E. H3-4 in the valley zone.
1 (971 pieces are separated at regular intervals.The next group of steel pieces has reached the heating zone population.Heating zone: 55 pieces of steel pieces)The steel pieces in the stirring circle B zone are in a fired state. It is good for determining the position and number of thinning <)<-ner zones.
The Nokuichiner in the B zone is thinning force and red. FIG. 6 shows the temperature in state V(a).

Furnace? Calculated from AiY, the flattening temperature of the metal plate heating material - non-metallic material, and the Okamekatakan 11JtTR located in the B zone is in a state of burnout compared to the steel plate in the Iya zone. I understand.

In order to escape from the supply of heat, the burner in zone B moves to zone A, and as a result of heat vibration measurement, q is 1 strand smaller, and the decision power for the position and number of burner zones to be thinned out is in zone A. The burners in zone B are thinned out, and the burners in zone B are lit. The next group of copper pieces reaches the E zone, but since the steel pieces in the E zone have a larger q due to the subtraction of the amount of heat supplied, the burner continues to ignite. In (c), the heat quantity of the steel pieces in the A zone is adjusted by thinning out the burners and sent to the soaking zone, and the burners in the A zone are ignited. The next group of steel slabs is advanced to the D zone, and the new copper slabs that have advanced to the E zone are well-baked and have a small heat quantity q, so the number of burners in the E zone is determined according to the position and number of burner zones to be thinned out. are thinned stones. ni)) indicates that all the steel slab groups that were in the heating zone have moved to the soaking zone and have entered the next group of 1 piece of steel, 11 passions. (The steel pieces are in the E zone of the paste/ζ proceed to the B zone, the steel pieces are all hot and dry, and from B.

The heat jtq of the steel slab in the D zone is small.The B zone and the D zone are thinned out according to the positioning force i of the burner zone and the number of burner zones subtracted by 4/S.

Batch confectionery is started in the state of
1. Stop and move the piece of steel up and down at Izf. (In the case of tears, the steel slabs of the B zone are baked in the hot spot which must be supplied by the prescribed extraction 1 j cutting, and the steel slabs of the D zone continue to be supplied with a small amount of heat. D according to the determination of the location and number of burner zones to be shown and thinned out.
One phrase is drawn from the zone's burner. (f)) All the burners are ignited in a state where the heating cover is uniformly supplied to all the copper pieces in the heating zone for a certain period of time.

1') [During fixed-time batch operation, the product is transported again and sent to the soaking zone. In the case of continuous operation, conditions (a) to (b) are repeated. Incidentally, if there is a zone where no steel pieces exist, as in (2) above, and there is surplus space in the burner zone to be thinned out, thinning can also be performed.

When charging 100'C (1) temperature with a good copper piece and a bad steel piece when charging a force of 1, the temperature of 100'C (1) at the time of creation in the rice promotion method is b○℃. However, with the combustion control of the present invention, the temperature could be improved by 3°C. In addition, due to thinning control, the energy consumption is 7% lower than before.

The control method of the present invention is not limited to only heating zones;
It can also be carried out in both the heating zone and the soaking zone. The difference in extraction temperature when extracting from both the Calcium M zone and the soaking zone is further improved. Furthermore, the heat iq can be calculated from the burner even if materials to be heated with different cross-sectional shapes or lengths are charged at the same time, or if the target extraction temperature differs for each piece within a lot, or if it differs between lots IMJ. It is possible to heat to a constant temperature with on/off control.

As described above, according to the uninvented combustion control method, the 9"
It has great effects, such as preventing ε overflow, baking to the target extraction temperature without variation, and further preventing combustion loss.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of heating f+.The second figure is a configuration diagram explaining a practical example in the tropics.Figure 3 is a diagram showing the estimated temperature position of a steel piece.Figure 4 Figure 5 shows the relationship between the fuel flow rate and the burner number of fires.
(E) and (F) are diagrams showing an example of the burner draw control of the present invention, and FIG. 6 is a diagram showing the temperature state in FIG. 5(A). 1... Charger 2... Extractor 3.35... Side burner 4.36... Walking beam 5...
... Pre-heating zone 6 ... Heating zone 7 ... ・Soaking zone 8 ・ ・ ・ ・ ・ Katana ■ Heat octopus 9 ・
・・・Partition wall 10 ・・・Copper piece 20・・・・Calculator 31・・・・Thermometer 32・・・・Thermometer for open side 1 34・・Heated material 35・・・・Heating zone 36... Walking beam drive device 3'7
...Shutoff valve 38...For fuel flow i adjustment day Applicant Nippon Steel Corporation Figure 5 35 俤GIA

Claims (1)

[Claims] Furnace temperature control of the heating zone, soaking zone, or both of the heating furnace is subdivided into each valley burner zone, and the average temperature of each heated material is estimated from the furnace temperature of each zone, and from this estimated temperature. Divide the amount of heat required for the material to be heated to reach the predetermined extraction temperature J paste at PJlya time and calculate the baked clay state of the material to be heated from the nuclear heat t1, Based on the tracking information in the burner 10 and the report on the tens of burners, it is determined which burner zone to thin out, and according to the determination, the fuel level of the burner zone to be thinned out is controlled by 1θ [masu τ ON, / OFF III] and transferred to the heated material. A combustion control method for a side burner-fired continuous heating furnace, characterized in that the supplied heat is adjusted to IR, and the temperature of the material to be heated is raised to a target extraction temperature without variation.