JPH0529809B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a burner ignition number control device for an in-furnace denitrification boiler, and more particularly to a burner ignition number control device for an in-furnace denitrification boiler that automatically ignites and extinguishes the burners. This invention relates to a number ignition control device.

[Conventional technology]

In conventional burner ignition number control devices, the burners are ignited in a predetermined order, and a bypass circuit is simply provided so that even if a burner fails to ignite, the next burner will ignite. .

Therefore, the conventional burner ignition number control device is not suitable for vertical combustion, which is effective for denitration in the furnace, and no NOx reduction effect can be expected.

[Problem that the invention seeks to solve]

The above conventional technology does not have a circuit to monitor the vertically aligned burners, and does not consider maximizing the NOx effect by arranging the burners vertically, so the NOx reduction effect is low. There was a problem.

The purpose of the present invention is to monitor the combustion of the burners arranged vertically, so that if the burner in the upper stage is not ignited, the burner in the upper stage is bypassed to the next burner. If the lower burner fails to ignite while the burner is igniting,
An object of the present invention is to provide a burner ignition number control device that controls the upper burner to be extinguished as well.

[Means for solving problems]

The problem described above is that in a burner ignition number control device for a burner arrangement consisting of multiple stages in which the burners of each stage are arranged vertically, the number of burners ignited is Based on the increase command, each burner in the upper stage having a predetermined relationship with the reference stage and located vertically aligned with the predetermined number of burners that have already been ignited is sequentially ignited to cause a misfire. If the burner is not lit, the first burner command to ignite the next burner is assumed to be in an unlit state.
ignition command means; an upper stage burner that has the predetermined relationship with each burner other than the predetermined number of burners in the reference stage and is vertically aligned with each burner other than the predetermined number; The burners in this set are set up in vertical pairs, and the burners in this set are ignited one after the other. If at least one burner in this set does not ignite, the other burner in this set is also extinguished and the next burner is lit. a second ignition command means for commanding the ignition of the burners in the unlit stages; commanding the ignition of the burners in the unlit stage sequentially from the lower stage to the upper stage, and in a predetermined order for each burner in each stage; The problem is solved by a burner ignition number control device including a third ignition command means;

[Effect]

After igniting a predetermined number of burners in the reference stage, based on a command to increase the number of burner ignitions from the first ignition command means, burners in the upper stage that have a predetermined relationship with the reference stage and that have already been ignited are The predetermined number of burners arranged in the vertical direction are sequentially ignited, and if a misfire occurs, the next burner is commanded to be ignited as an unignited state, and the second ignition command means is used to perform the ignition according to the reference. Among the burners in the stages, each burner other than the predetermined one and each burner in the upper stage having the predetermined relationship and located vertically aligned with each burner other than the predetermined number are vertically aligned. The burners of this set are ignited sequentially for each set, and when at least one burner of this set does not ignite, the other burner of this set is also extinguished and the ignition of the next set is commanded, and the third burner is The ignition command means commands the burners in the unlit stages to be ignited sequentially from the lower stage to the upper stage, and in each stage, each burner is commanded to ignite in a predetermined order.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. In this example, as shown in Fig. 2, a total of 48 burners are installed, 24 each in front of the can and in the can stage of the boiler furnace, and both the front and rear of the can are A to A.
It consists of four stages, and each stage is provided with six burners, and the burners of each stage are arranged in a line vertically and horizontally in a grid pattern.

FIG. 2 shows the ignition order of the six B-stage burners (total of the front and rear cans) that are ignited first, which is the burner ignition state before entering the control according to the present invention. First, the boiler starts by igniting the six burners in the B stage in groups of two, one in front of the can and one in the rear of the can, according to the order shown in the circle shown in FIG. The order from No. 4 to No. 6 is listed here because if a burner fails to ignite, the set of burners that failed to ignite will disappear at the same time, and the burner in the next order will go on to ignite. be.

A total of 6 Bs before and after the can that is lit first.
After the ignition of the stage burner is completed, in-furnace denitrification control begins. In-furnace denitrification control is as shown in Figure 1.
The amount of air for burner combustion in the vertical direction is 51a to 51f.
Adjust with the damper to set the A stage to 100% and the B stage to 100%.
80%, stage C 60%, and stage D 30%, reducing the amount as you go up to the top, thereby providing a gas phase reduction region in the furnace and reducing NO _x . Here, the NOx generated in the main combustion zone is converted to _N2 in the gas phase reduction zone.
It is reduced to +CO+H ₂ O, and further CO ₂ is generated by the air from the after-air port, and regenerated NOx
We are trying to suppress this. Therefore, by igniting the burners aligned vertically, the NOx reduction effect becomes greater.

The in-furnace denitrification control can be started when two or more lower burners among the burners arranged vertically have completed ignition. In this embodiment, the burners are ignited in the order shown in FIG. 3 based on the results of the in-furnace denitrification boiler test. The burners shown with double circles indicate the burners that were ignited in the previous stage.

FIG. 1 is an example of a system configuration of a burner ignition number control device with a built-in burner condition monitoring circuit and an in-furnace denitrification boiler. In Fig. 1, 100 is a burner ignition number control device, and 52a of the in-furnace denitrification boiler is 200.
Controls the ignition and extinguishing of the main burner ~52d. 5
The main burners 2a to 52d output a burner number command 1 according to the power supply command, and the main burners 52a to 52d are connected to the main burner valves 60a to 60d and the main burner valves 51
It is ignited by opening the combustion air dampers c to 51f. The starting state of the main burner source valves 60a to 60d automatically extinguishes the burner when a malfunction occurs that is detected by the limit switches 61a to 61d.

Here, the burner state monitoring circuit 20 for aligning the burner ignition states in the vertical direction will be described. This circuit 20
Here, it is assumed that the in-furnace denitrification control state has been entered, and that the six B-stage burners (total of the front and rear cans) have already completed ignition. The main burner of 52a is No. 1 burner ignition command 9
No. 1 burner ignition command 9a is ignited by No. 1 burner ignition command 9a, when both burner ignition number increase command 1 and vertical burner (in this case, stage B burner) ignition completion signal 2 are satisfied. , AND circuit 5a
It is output from Therefore, if the main valve 60c is not open and the lower burner (here, the B-stage burner 52c) has not been completely ignited by the limit switch 61c, the burner 52a will not be ignited. At this time, OR circuit 6
b, the next burner ignition command 9b is output. In addition, the conditions for moving to the next burner's ignition include a burner abnormality 3 and a signal that the burner to be ignited has already been ignited 4, and this signal is
This becomes a condition for igniting the next burner via the OR circuits 6a and 6b.

The burner status monitoring circuit 20b monitors the second burner, and if there are n burners, n
burner condition monitoring circuits are provided.

According to the burner ignition order shown in Figure 3, up to a total of 6 burners before and after the can in stage D are replaced by a total of 6 burners before and after the can in stage B, which have already completed ignition. At the same time, ignite the D stage burner located vertically. In this state, among the burners in the B stage, the total number of burners before and after the can that have not completed ignition is six in the B stage and six in the D stage. These burners are simultaneously ignited as a vertical pair of burners, one in the B stage and one in the D stage. This is 30
If the B stage and D stage burners have not completed ignition due to the circuit a, the AND condition of 5'a is established, and No.1B
Stage, D stage burner ignition command 50a is output. B
When stage and D stage burners are ignited, 40a
When the AND condition is satisfied, the next No. 2 burner is ignited. Here, the in-furnace denitrification effect appears when the burners in the upper and lower stages aligned in the vertical direction are ignited, so if either stage B or stage D, which is aligned in the vertical direction, becomes abnormal, 6'b Both the burners aligned vertically in the No. 1B and D stages are extinguished through the OR circuit (60a).

By the B stage and D stage burner ignition circuit of 30a, B
When all stage and D stage burners are ignited, the remaining C
Stage B and stage A burners are ignited by stage B and stage D burners, and all the vertical burners of stage B and stage D are in the in-furnace denitrification mode. , C stage, and A stage are ignited in the order shown in FIG.

According to this embodiment, when igniting the burner,
In the burners of a given stage, the burners arranged vertically are ignited.
It has a great effect on reducing NOx.

In addition, according to the No. 1 burner ignition command of 9a, the No. 1
When the burner fails to ignite, the 52a
It has a function to extinguish the burners, and a monitoring circuit has been added to ensure that only one burner aligned vertically is burning.

〔Effect of the invention〕

According to the present invention, the burners in the reference stage and the burners in the upper stage having a predetermined relationship with the reference stage are aligned in the vertical direction, and the burners in the reference stage are ignited first or simultaneously. However, when they are ignited at the same time, if one misfires, the other is also extinguished, resulting in combustion with excellent denitrification effects.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention;
2 is a burner layout diagram of the embodiment shown in FIG. 1, and FIG. 3 is a diagram showing the ignition order of the burners shown in FIG. 2. 20... Burner condition monitoring circuit, 30... B stage, D stage burner ignition circuit, 100... Burner ignition number control circuit.

Claims (1)

[Claims] 1. In a burner ignition number control device for a burner arrangement consisting of multiple stages in which burners in each stage are arranged vertically, after a predetermined number of burners in the standard stage have been ignited, the burner ignition number control device If the burners in the upper stage that have a predetermined relationship with the reference stage and that are aligned vertically with the predetermined number of burners that have already been ignited are ignited in sequence and a misfire occurs, the state is unignited. first ignition command means for commanding the ignition of the next burner;
Each burner other than the predetermined number among the burners in the reference stage and each burner in the upper stage having the predetermined relationship and located vertically aligned with each burner other than the predetermined number. The burners in each set are ignited in sequence in the vertical direction.
a second ignition command means for extinguishing the other burner of the set when at least one burner of the set does not ignite and instructing the ignition of the next set; Step by step,
A burner ignition number control device comprising: a third ignition command means for commanding ignition of each burner in a predetermined sequence in each stage;