JP3969200B2 - Thermal storage burner combustion control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a regenerative burner combustion control method in which a heating furnace is indirectly heated by a radiant tube with a plurality of regenerative burner machines.
[0002]
[Prior art]
Fig.11 (a) is a perspective view which shows schematic structure of the heating furnace of the radiant tube system integrated in the continuous processing line of the steel plate in an iron manufacturing plant. FIG. 11B is a schematic view seen from above, and FIG. 11C is a schematic view seen from the side. The steel plate 1 conveyed through the continuous processing line is guided into the heating furnace 3 through the carry-in roll 2a. In the heating furnace 3, a large number of rolls 2 c and 2 d are arranged with a predetermined interval, divided into an upper part and a lower part. The steel plate 1 introduced into the heating furnace 3 passes between the rolls 2c and 2d and is carried out of the heating furnace 3 through the carry-out roll 2b.
[0003]
A large number of regenerative burner machines 4 are embedded in the side walls 3 a on both sides of the heating furnace 3 so as to penetrate the side walls 3 a into the heating furnace 3. The flame of the regenerative burner 4 flows through the radiant tube 5 protruding into the heating furnace 3. Due to the heat of the flame flowing through the radiant tube 5, the steel plate 1 passing between the rolls 2c and 2d is indirectly heated.
[0004]
Generally, the inside of the heating furnace 3 is divided into a plurality of zones 6, and the temperature of the steel plate 1, that is, the heating temperature is controlled for each zone 6. Each zone 6 has a plurality of regenerative burner machines 4 and a radiant tube 5 connected to the regenerative burner machine 4. Therefore, the steel plate 1 introduced into the heating furnace 3 is sequentially heated in each zone 6 and then carried out of the heating furnace 3.
[0005]
FIG. 12 is a schematic cross-sectional view showing a schematic configuration of each regenerative burner machine 4 attached to the outer wall 3 a of each zone 6 of the heating furnace 3.
[0006]
Cylindrical burners 7a and 7b are attached to the openings of the radiant tube 5 formed in a substantially U shape toward the inside of the heating furnace 3 on the inner surface of the side wall 3a of the heating furnace 3, and the burners 7a and 7b are cylindrical. of Thermal storage 8a and 8b are connected. This burner 7a, 7b and Thermal storage The flow path 9 for the combustion air 21, the flow paths 14a and 14b for the pilot air 15, and the flow path 10 for the combustion gases 18 and 16 are formed in 8a and 8b. In each of the burners 7a and 7b, ignitions 11a and 11b for igniting the pilot 13 and detecting the ignition are provided.
[0007]
The burner fuel gas 18 is supplied to the burners 7a and 7b via the burner fuel gas cutoff valves 17a and 17b, and the pilot combustion gas 16 is supplied to the burners 7a and 7b via the pilot combustion gas cutoff valves 20a and 20b. On the other hand, the burner combustion air 21 is supplied to the burners 7 a and 7 b via a common burner combustion air shut-off valve 23 and a switching valve 24. Further, the pilot combustion air 15 is supplied to the burners 7a and 7b via the supply pipes 14a and 14b.
[0008]
Therefore, in this heat storage type burner machine 4, the nozzle only for pilot 13 is not provided, but this pilot 13 and regular flame 12 are burned by the same burners 7a and 7b.
[0009]
In the regenerative burner machine 4 having such a configuration, both the burners 7a and 7b are not in the combustion state at the same time, and only one of the burners 7a and 7b is in the combustion state. The flame 12 generated in the burning burner 7a passes through the radiant tube 5, and the other burner 7b (exhaust burner) and Thermal storage Exhaust gas 25 is exhausted to the outside through the flow path 9 of 8b and the switching valve 24 in the state of FIG. This exhaust gas 25 is Thermal storage In the process of passing through the flow path 9 of 8b, the standby tropical storage 8b and the burner 7b are kept at a high temperature.
[0010]
For example, when a certain time such as 30 seconds elapses, the supply of the burner fuel gas 18 to the burning burner 7a is stopped, and the supply of the burner fuel gas 18 to the other exhaust burner 7b is started. At the same time, the switching valve 24 is switched to switch the burner combustion air 21 to the other exhaust burner 7b. Then, the burner 7b is ignited, and the flame 12 generated in the burner 7b passes through the radiant tube 5 and the other burner 7a and Thermal storage Exhaust gas 25 is exhausted to the outside through the flow path 9 of 8a and the switching valve 24 in the reverse state of FIG. This exhaust gas 25 is Thermal storage In the process of passing through the flow path 9 of 8a, this exhaust (waiting) Thermal storage 8a and the burner 7a are kept warm.
[0011]
In this way, by burning each burner 7a, 7b alternately, Thermal storage Since 8a, 8b and the in-exhaust burners 7a, 7b can be maintained in a high temperature state, combustion of the burners 7a, 7b and switching of exhaust can be performed in a short time and efficiently.
[0012]
A combustion control method for each regenerative burner machine 4 of the heating furnace 3 to which a plurality of regenerative burner machines 4 having the configuration and functions are attached will be described.
[0013]
(A) Ignition and extinguishing of the regenerative burner 4
Each regenerative burner machine 4 belonging to each zone 6 of the heating furnace 3 is ignited and extinguished in each zone 6 unit. That is, first, the pilot combustion gas cutoff valves 20a and 20b are opened to supply the pilot combustion gas 16 to the burners 7a and 7b, and both the burners 7a and 7b in all the regenerative burner machines 4 belonging to the zone 6 are supplied. The pilot 13 is ignited by the ignition 11a, 11b. Next, the switching valve 24 of the regenerative burner machine 4 is operated to select the burners 7a and 7b to be ignited. Thereafter, the burner combustion gas 18 and the burner combustion air 16 are sequentially supplied to each heat storage burner machine 4. As a result, each regenerative burner 4 is ignited in turn.
[0014]
In this case, the minimum burner fuel gas and the minimum burner combustion air predetermined in this zone unit are continuously supplied from the ignition of the first regenerative burner unit 4 to the final ignition of the regenerative burner unit 4. When the ignition of all the regenerative burner machines 4 is completed, the burner combustion gas and the burner combustion air are raised to the burner combustion gas and the burner combustion air corresponding to the heating temperature of the corresponding zone 6.
[0015]
When extinguishing each heat storage type burner machine 4, the burner combustion gas and burner combustion air of each heat storage type burner machine 4 are shut off simultaneously, and each heat storage type burner machine 4 is extinguished simultaneously.
[0016]
(B) Switching between combustion and exhaust of each burner of the regenerative burner 4
The combustion and exhaust switching of the burners 7a and 7b of each regenerative burner machine 4 belonging to each zone 6 is carried out in each zone 6 unit. That is, in this case, since the pilots 13 of the burners 7a and 7b are always in a combustion state, the burner combustion gas cutoff valves 17a and 17b are operated to switch the switching valve 24 of each regenerative burner machine 4 to burn the burner. When the supply destination burner of the gas 18 and the burner combustion air 21 is switched, the switching destination burners 7a and 7b are automatically ignited by the presence of the pilot 13 and the flame 12 is generated.
[0017]
As described above, the burner combustion control for each regenerative burner machine 4 is performed for each zone 6 of the heating furnace 3 because the heating temperature or the like may be different for each zone 6.
[0018]
[Problems to be solved by the invention]
However, the following problems to be solved still exist in the regenerative burner combustion control method that implements the combustion control for each regenerative burner machine 4 in the above-described procedure.
[0019]
That is, for each zone 6 of the heating furnace 3, ignition, extinguishing processing, combustion of each burner, and exhaust gas switching processing are sequentially performed on each regenerative burner machine 4 belonging to the corresponding zone 6. The minimum burner combustion gas and the minimum burner combustion air are supplied in units of zone 6 until ignition of all the regenerative burner machines 4 belonging to zone 6 is completed. As a result, for the regenerative burner machine 4 ignited first, the minimum burner combustion gas and the minimum burner combustion air supplied to the corresponding zone 6 are supplied to one regenerative burner machine 4. .
[0020]
As a result, the burner combustion gas and strong wind caused by the burner combustion air hit the pilot 13 during combustion, and the pilot 13 misfires before the burners 7a and 7b are ignited, or misfires due to suction even after the burners 7a and 7b are ignited. To do. Furthermore, there is a concern that the pilots 13 of the burners 7a and 7b in the exhaust may misfire due to strong exhaust gas.
[0021]
The same can be said for the regenerative burner 4 that is ignited at the second or third unit. In this case, the burner combustion gas 18 and the burner combustion air 21 supplied to the regenerative burner machine 4 ignited at the second and third units are the first burner combustion gas 18 and the burner combustion air 21 described above. However, the wind pressure is still sufficient to cause the burning pilot 13 to misfire.
[0022]
If the pilot 13 misfires, there is a problem of exhausting unburned gas, which only makes the burners 7a and 7b unable to ignite. Furthermore, if the pilot 13 of the burner 7a, 7b in the exhaust gas misfires, there is a problem that combustion of the burner of the regenerative burner machine 4 and switching of the exhaust gas do not proceed smoothly.
[0023]
Further, when the position near the exhaust burner 7a, 7b of the regenerative burner machine 4 in the radiant tube 5 is heated to a high temperature by the exhaust gas of the flame 12 of the burning burner 7a, 7b, the exhaust burner 7a, Even if the pilot 13 of 7b is not burning, if the burner combustion gas 18 and the burner combustion air 21 are supplied, the corresponding burner may be automatically ignited.
[0024]
However, depending on the zone 6 of the heating furnace 3, the heating temperature may be set low. In such a case, since the temperature of the exhaust gas is low, the positions near the burners 7a and 7b in the exhaust of the heat storage burner 4 in the radiant tube 5 remain in a low temperature state. In such a state, if the pilot 13 of the exhaust burner 7a, 7b misfires due to the above-described reasons, the burner 7a, 7b of the switching destination is ignited at the time of combustion of the burner 7a, 7b of the heat storage burner 4 and switching of exhaust. There is a problem that does not, or requires a long time for ignition.
[0025]
The present invention has been made in view of such circumstances, and by adjusting the ignition timing for each regenerative burner machine included in each zone of the heating furnace and the amount of burner combustion gas or burner combustion air, Each of the regenerative burner machines belonging to the can be reliably ignited at the time of ignition, fire extinguishing, burner combustion, and exhaust switching, and the safety and temperature control accuracy of the heating furnace in which each regenerative burner machine is incorporated An object of the present invention is to provide a regenerative burner combustion control method that can be greatly improved.
[0026]
[Means for Solving the Problems]
The present invention attaches a plurality of radiant tube type heat storage burner machines to each zone of a heating furnace, and burner combustion gas supplied in units of each zone is a pair of each heat storage burner machine belonging to each zone. It burns alternately in the burner and heats the heating furnace through the radiant tube. Thermal storage It is applied to a regenerative burner combustion control method that stores heat.
[0027]
And in order to eliminate the said subject, in the thermal storage type burner combustion control method of this invention, when igniting each thermal storage type burner machine which belongs to each zone, pilot combustion gas is supplied to each thermal storage type burner machine A pilot is ignited, and a burner combustion gas that is a predetermined number of pilot combustion gases is supplied to each regenerative burner machine so that all the regenerative burner machines that belong to the corresponding zone are ignited simultaneously.
[0028]
In the regenerative burner combustion control method configured as described above, when each regenerative burner machine belonging to each zone is ignited, all the regenerative burner machines belonging to the corresponding zone are ignited simultaneously. Thus, igniting all the regenerative burner machines at the same time means that the burner combustion gas supplied for each zone is equally supplied to the burners of all the regenerative burner machines. Since a large amount of burner combustion gas is not supplied to this burner, it is possible to prevent pilot misfire due to strong winds.
[0029]
Further, in another heat storage burner combustion control method according to the invention described above, when switching between combustion and exhaust of each heat storage burner machine belonging to each zone, the temperature of the corresponding zone in the heating furnace or the radiant tube temperature From this, it is determined whether the temperature in the radiant tube is a temperature that requires pilot combustion to ignite the burner in the exhaust that is not in combustion in each regenerative burner machine, and the temperature in the radiant tube requires pilot combustion. Pilot ignition is performed, pilot combustion is confirmed, and the combustion burner is ignited by switching the burner combustion gas and air supply destination from the burning burner to the exhausting burner. extinguish a fire.
[0030]
Furthermore, when the temperature in the radiant tube does not require pilot combustion, another invention ignites the exhaust burner by switching the burner combustion gas and air supply destination from the burning burner to the exhaust burner. And extinguish the burner during combustion.
[0031]
In this way, it is determined whether the temperature in the radiant tube is a temperature that requires pilot combustion from the temperature of the corresponding zone or the radiant tube temperature in the heating furnace, and the pilot combustion is confirmed only when necessary. The relevant burner is ignited. Therefore, even if the heating temperature in the zone of the heating furnace is set low, combustion and exhaust of the burner of the regenerative burner machine can be switched reliably.
[0032]
Furthermore, in another invention, when each regenerative burner machine belonging to each zone is ignited, each regenerative burner machine is supplied with a burner combustion gas and air that is four times less than the pilot combustion gas and air. Yes.
[0033]
In this way, when the burner is ignited, the burner pilot gas is blown out by the burner combustion gas by supplying each of the regenerative burner machines with the burner combustion gas and air that is four times less than the pilot combustion gas and air. It was experimentally confirmed that this was prevented.
[0034]
Furthermore, in another invention, the timing of switching the combustion and exhaust of the burner of each regenerative burner machine belonging to each zone is shifted for each regenerative burner machine.
[0035]
In this way, the combustion and exhaust of each heat storage type burner machine belonging to each zone are switched at the same timing by shifting the timing of switching the combustion and exhaust of each heat storage type burner machine for each heat storage type burner machine. Compared with the case, the combustion amount and the pressure fluctuation of the exhaust gas in each burner of each regenerative burner machine can be suppressed to the minimum.
[0036]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram illustrating a configuration of a main part of a heat storage type burner combustion control system to which the heat storage type burner combustion control method of the embodiment is applied. FIG. 2 is a schematic cross-sectional view showing the state of attachment of the heat storage burner machine in units of zones to the heating furnace. The same parts as those in FIGS. 11 and 12 are denoted by the same reference numerals, and detailed description of the overlapping parts is omitted. Specifically, the heating furnace 3, the conveyance path of the steel plate 1 conveyed in the heating furnace 3, the arrangement of the regenerative burner machines 4 and the radiant tubes 5 attached to the side walls 3a of the heating furnace 3, and The arrangement of each zone 6 is the same as in FIG. Therefore, FIG. 1 is a diagram showing an extracted main part of the regenerative burner combustion control system shown in FIG. In FIG. 1, only the regenerative burner machine 4 and the radiant tube 5 provided on the side wall 3 a on one side of the heating furnace 3 are shown to simplify the explanation.
[0037]
A thermometer 30 that detects the temperature in the heating furnace 3 is attached to each zone 6 of the heating furnace 3 to which the regenerative burner combustion control system of this embodiment is applied. In addition, the structure of each heat storage type burner machine 4 attached to each zone 6 of the heating furnace 3 is substantially the same as the conventional heat storage type burner machine 4 shown in FIG.
[0038]
In this embodiment system, a combustion gas source 31, a burner combustion air source 32, a pilot combustion air source 33, a shutoff valve drive unit 34, a switching valve drive unit 35, a burner combustion control unit 36, and an operation unit 37 are provided. .
[0039]
The combustion gas source 31 supplies the burner combustion gas 18 and the pilot combustion gas 16 to each regenerative burner machine 4 in each zone 6. Similarly to the combustion gas source 31, the burner combustion air source 32 supplies the burner combustion air 21 to each regenerative burner machine 4 in each zone 6. Further, the pilot combustion air source 33 supplies the pilot combustion air 15 to each regenerative burner machine 4.
[0040]
The shut-off valve drive unit 34 performs opening / closing control of each shut-off valve based on an instruction from the burner combustion control unit 36. Further, the shut-off valve drive unit 34 adjusts the opening degree of each flow control valve based on an instruction from the burner combustion control unit 36. Further, the switching valve drive unit 35 performs switching control of the switching valve 24 of each heat storage type burner machine 4 based on an instruction from the burner combustion control unit 36. For example, the burner combustion control unit 36 formed by a computer or the like ignites and extinguishes each regenerative burner machine 4 in each zone 6 and burns and exhausts the burners 7a and 7b in accordance with instructions from the operator via the operation unit 27. Implement switching control.
[0041]
In FIG. 2, the combustion gas supplied from the combustion gas source 31 is supplied to each regenerative burner machine 4 as the burner combustion gas 18 through the zone burner combustion gas flow control valve 38 and the zone burner combustion gas cutoff valve 39. The zone burner combustion gas flow control valve 38 adjusts the flow rate of the burner combustion gas 18 supplied to the corresponding zone 6. That is, the burner combustion gas 18 having a flow rate corresponding to the set temperature in the heating furnace 3 of the corresponding zone 6 is supplied for each zone 6. As a result, each regenerative burner machine 4 belonging to each zone 6 is supplied with an amount of burner combustion gas 18 controlled by the number of regenerative burner machines 4 installed. Further, the combustion gas supplied from the combustion gas source 31 is directly supplied as pilot combustion gas 16 to each regenerative burner 4.
[0042]
The burner combustion air 21 supplied from the burner combustion air source 32 is adjusted to a flow rate corresponding to the zone 6 by the zone burner combustion air flow control valve 40 and supplied to each regenerative burner machine 4. The pilot combustion air 15 supplied from the pilot combustion air source 33 is directly supplied to each regenerative burner machine 4.
[0043]
The burner combustion control unit 36 in the regenerative burner combustion control system configured as described above performs combustion control on each regenerative burner machine 4 in each zone 6 of the heating furnace 3 according to the flowchart of FIG. 3.
[0044]
When the operator inputs an operation start command for the entire system through the operation unit 37, the pilot 13 is ignited and the combustion / exhaust switching process is performed (P1). Next, ignition processing of the burners 7a and 7b is performed (P2). Thereafter, if an operation end command is not input (P3), when a fixed time such as 60 seconds corresponding to the burner combustion / exhaust switching period elapses (P4), the thermometer 30 attached to each zone 6 is heated. The furnace temperature of the furnace 3 is detected, and the temperature in the vicinity of the exhaust burners 7a and 7b in the radiant tube 5 in the corresponding zone 6 is estimated from the furnace temperature, and the temperature in the radiant tube 5 is determined as the corresponding burner. It is determined whether the temperature requires the combustion of the pilot 13 for ignition of 7a and 7b (P5).
[0045]
In the case of a low temperature that requires the combustion of the pilot 13, the process of switching the combustion / exhaust of the burners 7a, 7b (pilot combustion burner switching process) is performed after confirming the combustion of the pilot 13 (P6). Further, in the case of a high temperature that does not require the combustion of the pilot 13, a process (automatic combustion burner switching process) for immediately switching the combustion / exhaust of the burners 7a, 7b without confirming the combustion of the pilot 13 is performed (P7). .
[0046]
And if an operation end command is inputted in P3, fire extinguishing processing of each regenerative burner machine 4 will be carried out (P8).
[0047]
Next, the detailed operation of each process will be described in order using each flowchart.
4, 5 and 6 are flowcharts showing the detailed operation of the pilot ignition and combustion / exhaust processing of P1. Pilot combustion air 15 is supplied from the pilot combustion air source 33 to each regenerative burner 4 (S1). The fuel gas source 31 is activated (S2). When the operator turns on the pilot ignition switch of the operation unit 37 in this state (S3), the regenerative burner machines 4 are arranged in the order of combustion / exhaust switching preset for the regenerative burner machines 4 belonging to the block 6. The pilot ignition process is started (S4).
[0048]
First, the switching valve 24 is switched to the burner side scheduled for combustion (S5, S6). The ignitions 11a and 11b of the combustion burners 7a and 7b are energized (ON) (S7). In this state, the pilot combustion gas valves 20a and 20b of the combustion burners 7a and 7b are opened (S8).
[0049]
In S9, when the combustion of the pilot 13 is confirmed by the flame detection function of the ignition 11a, 11b, the ignition 11a, 11b is shut off (OFF) (S10). In this state, the burner pilot 13 to be burned is burning (S11). In S9 and S12, if the combustion of the pilot 13 cannot be confirmed for a certain period, it is determined that the pilot has not been ignited or misfired, the pilot combustion gas valves 20a and 20b of the combustion burners 7a and 7b are closed, and the corresponding ignition 11a , 11b are cut off (S13).
[0050]
If the ignition process of the pilots 13 of the burners 7a and 7b on the combustion scheduled side of all the regenerative burner machines 4 belonging to the corresponding zone 6 has not been completed (S14), the next regenerative burner machine 4 is in S15. Ignition processing for the pilot 13 is started (S15).
[0051]
When the ignition process of the pilots 13 of the burners 7a and 7b on the combustion scheduled side of all the regenerative burner machines 4 belonging to the relevant zone 6 is completed in S14, all the regenerative burners belonging to the relevant zone 6 are obtained after S16. In accordance with the combustion / exhaust switching timing of the burners 7a and 7b of the machine 4, that is, at the timing when the burner 7a and 7b to be exhausted are switched to the burner 7a and 7b to be combusted, the combustion is newly changed to the combustion schedule. Ignition processing of the pilots 13 of the burners 7a and 7b of each regenerative burner machine 4 is performed.
[0052]
Note that the timing of switching the combustion and exhaust of the burners 7a and 7b of each regenerative burner machine 4 belonging to one zone 6 in a cycle of 30 seconds is shifted every predetermined time for each regenerative burner machine 4.
[0053]
When the burner 7a, 7b of one regenerative burner machine 4 belonging to the corresponding zone 6 has reached the combustion / exhaust switching timing and the switching valve 24 starts switching (S17), both the regenerative burner machines 4 The pilot combustion gas cutoff valves 20a and 20b are closed, and the pilots 13 of both the burners 7a and 7b are once extinguished (S18). When the switching valve 24 finishes switching (S19), the ignitions 11a and 11b of the burners 7a and 7b newly on the combustion side are energized (ON) (S20). In this state, the pilot combustion gas valves 20a, 20b of the burners 7a, 7b on the combustion side are opened (S21).
[0054]
In S22, when the combustion of the pilot 13 is confirmed by the flame detection function of the ignition 11a, 11b, the ignition 11a, 11b is shut off (OFF) (S23). In this state, the pilot 13 scheduled to burn is burning (S24). If the combustion of the pilot 13 cannot be confirmed for a certain period in S22 and S25, it is determined that the pilot is not ignited or misfiring, the pilot combustion gas valves 20a and 20b of the combustion burners 7a and 7b are closed, and the corresponding ignition 11a , 11b are shut off (S26).
[0055]
If the ignition processing of the pilots 13 of the burners 7a and 7b newly burned in all the regenerative burner machines 4 belonging to the corresponding zone 6 has not been completed (S27), the next regenerative burner is obtained in S28. The ignition process for the pilot 13 of the machine 4 is started.
[0056]
In S27, when the ignition processing of the pilots 13 of the burners 7a and 7b scheduled to burn in all the regenerative burner machines 4 belonging to the corresponding zone 6 is completed, the current pilot ignition and combustion / exhaust switching processing is ended.
[0057]
In such a pilot 13 ignition system, the pilots 13 of the burners 7a and 7b scheduled to burn in the regenerative burner machines 4 belonging to the zone 6 are ignited, but the pilots 13 of the burners 7a and 7b scheduled to be exhausted are Not ignited. This is because the pilots 13 in the exhaust burners 7a and 7b are easily misfired by the exhaust gas.
[0058]
Next, the detailed operation of the burner ignition process at P2 in FIG. 3 will be described with reference to FIG.
When the operator presses the burner ignition switch of the operation unit 37 (Q1), ignition processing of each regenerative burner machine 4 belonging to the zone 6 designated for operation is started (Q2). Then, the burner combustion gas cutoff valves 17a and 17b of the burners 7a and 7b scheduled to be burned designated by the switching valve 24 in all the regenerative burner machines 4 belonging to the corresponding zone 6 are opened (Q3). Next, the flow rate of the burner combustion air 21 supplied to each regenerative burner machine 4 at the zone burner combustion air flow control valve 40 in the corresponding zone 6 is set to be, for example, three times or more and four times or less the flow rate of the pilot combustion air 15. (Q4).
[0059]
Next, the zone burner combustion gas shut-off valve 39 in the corresponding zone 6 is opened (Q5). Further, the flow rate of the burner combustion gas 18 supplied to each regenerative burner machine 4 at the zone burner combustion gas flow control valve 38 of the corresponding zone 6 is, for example, 3 times or more and 4 times or less the flow rate of the pilot combustion gas 16. Adjust (Q6).
[0060]
In this state, since the burner combustion gas 18 and the burner combustion air 21 are supplied to the burners 7a and 7b to be burnt designated by the switching valves 24 in all the regenerative burner machines 4 belonging to the corresponding zone 6, In the pilot 13, the burners 7a and 7b scheduled to burn are ignited and a flame 12 is generated.
[0061]
In such an ignition method for the burners 7a and 7b of the regenerative burner machine 4, when each regenerative burner machine 4 belonging to each zone 6 is ignited, all of the regenerative burner machines 4 belonging to the corresponding zone 6 are used. The combustion side burners 7a and 7b are ignited simultaneously. Thus, simultaneously igniting the burners 7a and 7b of all the regenerative burner machines 4 means that the burner combustion gas supplied for each zone is equal to the combustion side burners 7a and 7b of all the regenerative burner machines 4. Therefore, since a large amount of burner combustion gas 18 and a large amount of burner combustion air 21 are not supplied to the burners 7a and 7b of the specific heat storage type burner machine 4, the misfire of the pilot 13 due to strong winds is prevented. Occurrence can be prevented.
[0062]
Further, when the burner is ignited, each of the regenerative burner machines 4 is supplied with the burner combustion gas 18 and the burner combustion air 21 that are three to four times the pilot combustion gas 16 so that the burning pilot burns. It is reliably prevented that the gas 18 and the burner combustion air 21 are blown out.
[0063]
Next, the detailed operation of the pilot combustion burner switching process at P6 in FIG. 3 will be described with reference to FIGS.
When the combustion / exhaust switching timing of the burners 7a, 7b of the relevant heat storage type burner machine 4 arrives and the switching valve 24 starts switching (R1), the pilot combustion gas cutoff valves 20a, 20b of both of the relevant heat storage type burner machine 4 The burner combustion gas cutoff valves 17a and 17b are closed, and both the burners 7a and 7b and both pilots 13 are extinguished once (R2). When the switching valve 24 finishes switching (R3), the ignitions 11a and 11b of the burners 7a and 7b that are newly on the combustion side this time are energized (ON) (R4). In this state, the pilot combustion gas valves 20a and 20b of the combustion side burners 7a and 7b are opened (R5).
[0064]
In R6, when the combustion of the pilot 13 is confirmed by the flame detection function of the ignition 11a, 11b, the ignition 11a, 11b is shut off (R7). In this state, since the pilot 13 of the combustion side burners 7a and 7b is burning, the burner combustion gas valves 17a and 17b of the combustion side burners 7a and 7b are opened (R8). Therefore, the combustion side burners 7a and 7b are ignited and a flame 12 is generated.
[0065]
If the combustion of the pilot 13 cannot be confirmed for a certain period at R6 and R9, it is determined that the pilot has not been ignited or misfired, and the pilot combustion gas valves 20a and 20b of the combustion side burners 7a and 7b are closed, and the corresponding ignition is performed. 11a and 11b are shut off (OFF) (R10). Therefore, the combustion side burners 7a and 7b are not ignited.
[0066]
When the combustion / exhaust switching process of the burners 7a and 7b of the relevant heat storage type burner machine 4 is completed, the heat storage type burner machine 4 to which the combustion / exhaust switching process is executed next is selected (R11), and FIG. Return to P3.
[0067]
Next, the detailed operation of the automatic combustion pilot combustion burner switching process at P7 in FIG. 3 will be described with reference to FIG.
When the combustion / exhaust switching timing of the burners 7a, 7b of the relevant heat storage type burner machine 4 arrives and the switching valve 24 starts switching (U1), both pilot combustion gas cutoff valves 20a, 20b of the relevant heat storage type burner machine 4 And both the burner combustion gas cutoff valves 17a and 17b are closed, and both the burners 7a and 7b and both pilots 13 are extinguished once (U2). When the switching valve 24 finishes switching (U3), the burner combustion gas cutoff valves 17a and 17b of the burners 7a and 7b newly on the combustion side this time are opened (U4). Since the temperature in the vicinity of the burner 7a, 7b that has become the combustion side this time in the radiant tube 5 is sufficiently high, even if the pilot 13 is not burning, the corresponding burner 7a, 7b is automatically ignited and flame 12 is produced.
[0068]
When the combustion / exhaust switching process of the burners 7a and 7b of the relevant heat storage type burner machine 4 is completed, the heat storage type burner machine 4 to which the combustion / exhaust switching process is executed next is selected (U5), and FIG. Return to P3.
[0069]
In this way, the position in the vicinity of the exhaust-side burner 7a (7b) of the regenerative burner machine 4 in the radiant tube 5 is kept warm by the exhaust gas of the flame 12 output from the combustion-side burner 7b (7a) to the heating furnace 3. Therefore, the temperature in the vicinity of the burner 7a (7b) on the exhaust side of the regenerative burner machine 4 in the radiant tube 5 is a temperature corresponding to the temperature measured by the thermometer 30 of each zone 6 in the heating furnace 3. Become.
[0070]
Accordingly, when the combustion / exhaust switching of the burners 7a and 7b of each regenerative burner machine 4 belonging to each zone 6 is performed, the temperature in the radiant tube 5 from the temperature of the corresponding zone 6 in the heating furnace 3 is changed to the burner 7a. , 7b is determined whether or not the temperature of the pilot 13 needs to be combusted. Only when necessary, the combustion of the pilot 13 is confirmed and the corresponding burners 7a and 7b are ignited. Yes.
[0071]
Therefore, even if the heating temperature in the zone 6 of the heating furnace 3 is set low, the combustion / exhaust of the burners 7a and 7b of the regenerative burner machine 4 can be switched reliably.
[0072]
Further, when the combustion of the pilot 13 is not necessary for the ignition of the corresponding burner, the ignition of the regenerative burner machine 4 is naturally performed without performing the ignition of the pilot 13 from the beginning without checking the existence of the pilot 13 combustion. Since the combustion / exhaust switching of the burners 7a and 7b can be performed, the processing burden on the burner combustion control unit 36 can be reduced and the amount of pilot combustion gas 16 used can be reduced.
[0073]
Further, since the pilots 13 of the exhaust burner burners 7a and 7b that are not in the combustion of each regenerative burner 4 are always extinguished, the amount of pilot combustion gas 16 used can be reduced, and the pilot 13 can be misfired during combustion. The unburned gas of the pilot combustion gas 16 is not generated.
[0074]
In addition, the timing of switching the combustion and exhaust of the burners 7a and 7b of each regenerative burner machine 4 belonging to one zone 6 at a cycle of, for example, 30 seconds by switching the switching valve 24 is predetermined for each regenerative burner machine 4. It is shifted every hour. Therefore, it is possible to prevent the combustion amount and exhaust gas fluctuations in each regenerative burner machine 4 from being concentrated at the same timing due to the change of the flow direction of the burner combustion gas 21 by switching the switching valve 24. As a result, the control accuracy of the entire regenerative burner combustion control system can be further improved.
[0075]
【The invention's effect】
As described above, in the regenerative burner combustion control method of the present invention, all the regenerative burner machines belonging to each zone are ignited simultaneously. Therefore, since a large amount of burner combustion gas is not supplied to the burner of a specific heat storage type burner machine, it is possible to prevent pilot misfire due to strong winds.
[0076]
Also, it is determined whether the temperature of the radiant tube is a temperature that requires pilot combustion for burner ignition, and only when necessary, the pilot combustion is confirmed and ignition of the corresponding burner is performed. ing. Therefore, even if the heating temperature in the zone of the heating furnace is set low, combustion and exhaust of the burner of the regenerative burner machine can be switched reliably.
[0077]
Therefore, the safety and temperature control accuracy of the furnace equipped with each regenerative burner can be greatly improved.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a schematic configuration of a regenerative burner combustion control system to which a regenerative burner combustion control method according to an embodiment of the present invention is applied.
FIG. 2 is a schematic cross-sectional view showing a schematic configuration of a regenerative burner machine incorporated in the system of the same embodiment
FIG. 3 is a flowchart showing an overall processing operation executed by a burner combustion control unit incorporated in the system of the same embodiment;
FIG. 4 is a flowchart showing a detailed operation of pilot ignition and combustion / exhaust switching processing executed by the burner combustion control unit;
FIG. 5 is a flowchart showing detailed operations of pilot ignition and combustion / exhaust switching processing executed by the burner combustion control unit.
FIG. 6 is a flowchart showing detailed operations of pilot ignition and combustion / exhaust switching processing executed by the burner combustion control unit.
FIG. 7 is a flowchart showing a detailed operation of burner ignition processing executed by the burner combustion control unit;
FIG. 8 is a flowchart showing a detailed operation of a pilot combustion burner switching process executed by the burner combustion control unit.
FIG. 9 is a flowchart showing a detailed operation of a pilot combustion burner switching process executed by the burner combustion control unit.
FIG. 10 is a flowchart showing a detailed operation of an automatic combustion burner switching process executed by the burner combustion control unit.
FIG. 11 is a view showing a heating furnace equipped with a general heat storage burner.
FIG. 12 is a schematic cross-sectional view showing a schematic configuration of a general heat storage burner.
[Explanation of symbols]
1 ... Steel plate
3. Heating furnace
4 ... Thermal storage burner
5 ... Radiant tube
6 ... Zone
7a, 7b ... Burner
11a, 11b ... Ignition
12 ... Flame
13 ... Pilot
15 ... Pilot combustion air
16 ... Pilot combustion gas
17a, 17b ... burner combustion gas shut-off valve
20a, 20b ... Pilot combustion gas cutoff valve
18 ... Burner combustion gas
21 ... Burner combustion air
24 ... Switching valve
30 ... Thermometer
31 ... Combustion gas source
32 ... Burner combustion air source
33 ... Pilot combustion air source
36 ... Burner combustion control unit

Claims (5)

A plurality of radiant tube type regenerative burner machines are attached to each zone of the heating furnace, and the burner combustion gas supplied for each zone is alternately switched between a pair of burners of each regenerative burner machine belonging to each zone. In the regenerative burner combustion control method for burning and heating the heating furnace through a radiant tube, and storing heat in a heat storage body of a burner that is not in combustion among the pair of burners with the heated exhaust gas,
When igniting each regenerative burner machine belonging to each zone,
Supply pilot combustion gas to each of the regenerative burner machines to ignite the pilot,
A regenerative burner combustion control method characterized in that a burner combustion gas of a predetermined number of times of the pilot combustion gas is supplied to each of the regenerative burner machines, and all the regenerative burner machines belonging to the corresponding zone are ignited simultaneously. When switching the combustion and exhaust of the burner of each regenerative burner machine belonging to each zone,
From the temperature of the corresponding zone or the radiant tube temperature in the heating furnace, it is determined whether or not the temperature in the radiant tube is a temperature that requires pilot combustion to ignite the burner in the exhaust that is not in the combustion of each regenerative burner machine. ,
When the temperature in the radiant tube is a temperature that requires pilot combustion, pilot ignition is performed, and pilot combustion is confirmed,
2. The regenerative burner combustion control according to claim 1, wherein the burner combustion gas and air are switched from the burning burner to the exhaust burner to ignite the exhaust burner and extinguish the burning burner. Method. When the temperature in the radiant tube does not require pilot combustion, the combustion burner is ignited by switching the burner combustion gas and air supply destination from the burning burner to the exhausting burner, and the burning burner is The regenerative burner combustion control method according to claim 2, wherein the fire is extinguished. When each regenerative burner machine belonging to each of the zones is ignited, burner combustion gas and air that are four times less than the pilot combustion gas and air are supplied to each regenerative burner machine. The regenerative burner combustion control method according to any one of claims 1 to 3. The regenerative burner combustion control according to any one of claims 1 to 4, wherein the timing of switching the combustion and exhaust of each regenerative burner machine belonging to each zone is shifted for each regenerative burner machine. Method.

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