JP2002071130A - Method of discriminating adhesion of clinker of pulverized coal burning boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the method of discriminating the adhesion of clinker of a pulverized coal burning boiler which is capable of discriminating whether a burner throat is adhered with the clinker, preventing the burnout of a burner by suspending the permission of the ignition of the burner when the burner throat is adhered with the clinker, avoiding degrading the heat concentration of a furnace, and preventing the damage of the furnace by the fallen clinker by removing the adhered clinker at an early stage. SOLUTION: Whether or not a burner throat 2 is adhered with clinker 16 is discriminated based on a detecting signal 12 from a flame detector 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining clinker adhesion in a pulverized coal-fired boiler.

[0002]

2. Description of the Related Art In general, a pulverized coal-fired boiler is configured to mix fine coal pulverized by a mill with primary air, supply the pulverized coal to a pulverized coal burner, eject the pulverized coal from the burner, and perform floating combustion.

FIG. 2 shows an example of a conventional burner device in a pulverized coal-fired boiler, and a furnace wall 1a of a furnace 1 of the boiler.
A pulverized coal burner 4 for injecting and burning pulverized coal as a main fuel finely pulverized by a mill 3 is installed at the center of a burner throat 2 formed at a plurality of required locations in the above, and the axis of the pulverized coal burner 4 At the core, an oil burner 5 that injects and burns oil fuel such as heavy oil in a mist state by a spray medium such as steam is provided so as to be able to be inserted and removed, and ignition fuel such as gas or light oil is sprayed with steam or the like. An ignition torch 6 which is sprayed and burned in a mist form by a medium, and an ignition plug 7 for igniting the ignition torch 6
Are disposed so as to be able to be inserted into and removed from an insertion tube 8 provided near the pulverized coal burner 4.

In FIG. 2, reference numeral 9 denotes secondary air for combustion, 10
Is a register vane for applying a swirling force to the secondary air 9.

In the case of the above-described burner device, when performing ignition, first, the tip of the oil burner 5 is projected from the opening of the tip of the pulverized coal burner 4, and the ignition torch 6 and the ignition plug 7 are inserted into the cylinder. The ignition torch 6 and the ignition plug 7 are protruded from the distal end opening of the insertion tube 8 so that the distal end of the ignition torch 6 and the ignition plug 7 are positioned near the distal end of the oil burner 5. A spray medium is introduced to mix and inject the two, and the mixture is ignited by a spark plug 7.
To the oil burner 5 using the flame of the ignition torch 6 as an ignition source.
Further, the pulverized coal as the main fuel from the mill 3 is guided and injected into the pulverized coal burner 4, and the pulverized coal burner 4 is ignited by using the flame of the oil burner 5 as an ignition source.

When the oil burner 5 is ignited and the combustion of the oil fuel is started, the supply of the ignition fuel and the spray medium to the ignition torch 6 is stopped, and the ignition torch 6 is extinguished. When the pulverized coal 6 and the ignition plug 7 are pulled out of the insertion tube 8 and the pulverized coal burner 4 is ignited to start burning the pulverized coal as the main fuel, the supply of the oil fuel and the spray medium to the oil burner 5 is stopped. Oil burner 5 is extinguished and retreats into pulverized coal burner 4,
A transition is made to combustion by the pulverized coal burner 4.

On the other hand, in the vicinity of the burner device, a furnace 1
A flame detector 11 for confirming the presence or absence of a burner flame in the vessel, and when the boiler is operating, a detection signal 12 from the flame detector 11 is input to a flame monitoring circuit 13;
In the flame monitoring circuit 13, based on the detection signal 12 from the flame detector 11, a high-frequency component 15 a (about 100 [Hz]) of light brightness 14 and light flicker 15.
By detecting the presence or absence of an individual flame (self-flame), the low-frequency component 1 of the light brightness 14 and the light flicker 15 based on the detection signal 12 from the flame detector 11
5b (approximately 2.5 to 10 [Hz]), the presence or absence of another flame of another burner is recognized, and it is determined whether or not there is a flame on the tip side of the burner.

The high-frequency component 1 of the light flicker 15
5a and the low-frequency component 15b are extracted by a band-pass filter (BPF) not shown.

[0009]

In the case of the above-mentioned pulverized coal-fired boiler, the ash contained in the flue gas is melted and adhered to the peripheral portion of the burner throat 2 and is easily deposited as a clinker. When the clinker accumulates on the peripheral edge of the burner throat 2, when the pulverized coal burner 4 is ignited, when the ignition torch 6 moves from the flame to the oil burner 5, the ignition torch 6 flame is entrained into the burner throat 2 and injected from the oil burner 5. The generated oil rebounds into the pulverized coal burner 4 and may cause burner burnout.

When the clinker accumulates on the peripheral portion of the burner throat 2 as described above, it causes a decrease in the heat collection of the furnace 1 and the clinker which has grown greatly falls off the peripheral portion of the burner throat 2. Furnace 1 in case
Could be damaged.

According to the present invention, it is possible to determine whether or not the clinker has adhered to the burner throat in view of such circumstances.
If the clinker has adhered, burner burnout can be prevented by not giving permission to ignite the burner.In addition, by removing the attached clinker at an early stage, the heat recovery of the furnace and the clinker can be reduced. It is an object of the present invention to provide a method for determining clinker adhesion of a pulverized coal-fired boiler capable of avoiding damage to a furnace caused by falling of a furnace.

[0012]

SUMMARY OF THE INVENTION The present invention relates to a method for judging clinker adhesion of a pulverized coal-fired boiler in which a plurality of burners are provided in a furnace and a flame detector is provided for each burner. The present invention relates to a clinker adhesion determining method for a pulverized coal-fired boiler, which comprises determining whether or not clinker is attached to a burner throat based on a detection signal from a flame detector.

According to the above means, the following effects can be obtained.

When no clinker is deposited on the burner throat, the detection signal from the flame detector becomes a signal having a certain flickering width, and an individual flame or another flame is detected. It is determined that it is not attached.

On the other hand, when the clinker adheres and accumulates on the burner throat, the detection of the flame light by the flame detector is interrupted by the clinker, and the detection signal from the flame detector indicates that an individual flame or another flame is detected. In contrast to this, since the signal becomes a stable low-level constant signal, it is determined that the clinker is attached to the burner throat.

Here, when it is determined that the clinker is attached to the burner throat based on the detection signal from the flame detector while the corresponding burner is extinguished,
If it is included in the sequence so as not to issue the ignition permission to the burner, the ignition torch flame will not be caught in the burner throat and the oil injected from the oil burner will not bounce into the pulverized coal burner, etc. Is prevented.

Further, if it is determined that the clinker is attached to the burner throat based on the detection signal from the flame detector as described above, the attached clinker is removed at an early stage. The heat absorption is not reduced, and the possibility that the clinker that has grown large is peeled off from the burner throat and falls to damage the furnace is reduced.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an example of an embodiment of the present invention. In the figure, the portions denoted by the same reference numerals as those in FIG. 2 represent the same components, and the basic configuration is the same as that of the conventional device shown in FIG. It is the same as that shown in FIG. 1, but the feature of the illustrated example is that, based on a detection signal 12 from a flame detector 11, as shown in FIG.
The point is that it is determined whether or not the clinker 16 is attached to the burner throat 2.

Normally, individual flames and other flames detected in a state where the clinker 16 is not attached and deposited on the peripheral portion of the burner throat 2 each have a flickering signal having a certain width. When the clinker 16 adheres and accumulates on the peripheral portion of the burner throat 2 as shown by a virtual line, the detection of the flame light by the flame detector 11 is interrupted by the clinker 16, and the individual flame or another flame is detected. Since it is clearly different from the time when the flame detector 11 outputs a stable low-level signal from the flame detector 11,
In the illustrated example, attention is paid to this point, and the flame detector 11 originally provided for detecting the flame is connected to the clinker 1.
6 is used to determine the adhesion.

Next, the operation of the illustrated example will be described.

A clinker 16 is provided on the periphery of the burner throat 2.
In a state in which no flame is deposited, the detection signal 12 from the flame detector 11 becomes a signal having a certain flickering width, an individual flame or another flame is detected, and the clinker 16 is adhered to the burner throat 2. It is determined that there is not.

On the other hand, when the clinker 16 adheres and accumulates on the peripheral portion of the burner throat 2 as shown by a virtual line in FIG.
The detection of flame light by the flame detector 11 is blocked by the clinker 16, and the detection signal 12 from the flame detector 11 is output.
Unlike the case where the individual flame or the other flame is detected, the signal becomes a stable low-level signal, and therefore, it is determined that the clinker 16 is attached to the burner throat 2.

Here, when it is determined that the clinker 16 is attached to the burner throat 2 based on the detection signal 12 from the flame detector 11 while the corresponding pulverized coal burner 4 is extinguished, If it is incorporated in the sequence so as not to issue the ignition permission to the burner, the ignition torch 6 does not involve the flame in the burner throat 2 and the oil injected from the oil burner 5 rebounds into the pulverized coal burner 4. , Burner burnout is prevented.

As described above, the clinker 16 is applied to the burner throat 2 based on the detection signal 12 from the flame detector 11.
If it is determined that the clinker 16 is attached, if the attached clinker 16 is removed at an early stage, the heat collection of the furnace 1 will not be reduced, and the clinker 16 that has grown greatly will be removed from the periphery of the burner throat 2. The possibility that the furnace 1 is damaged by being peeled off from the portion and falling is reduced.

In this way, it is possible to determine whether or not the clinker 16 has adhered to the burner throat 2.
When the burner is adhered, burner burnout can be prevented by not giving permission to ignite the burner, and by removing the attached clinker 16 at an early stage, the heat recovery of the furnace 1 can be reduced, and Damage to the furnace 1 due to the fall of the clinker 16 can be avoided.

The method for determining the clinker adhesion of the pulverized coal-fired boiler of the present invention is not limited to the above-described illustrated example, and various changes can be made without departing from the scope of the present invention. It is.

[0028]

As described above, according to the method for determining clinker adhesion of a pulverized coal-fired boiler of the present invention, it is possible to determine whether or not clinker has adhered to a burner throat. In addition, burner burnout can be prevented beforehand by not permitting ignition of the burner, and by lowering the attached clinker at an early stage, it is possible to reduce the heat recovery of the furnace and damage the furnace due to the fall of the clinker. An excellent effect that it can be avoided can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an example of an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a conventional example.

[Explanation of symbols]

 Reference Signs List 1 furnace 2 burner throat 4 pulverized coal burner (burner) 11 flame detector 12 detection signal 13 flame monitoring circuit 16 clinker

Continued on the front page F term (reference) 3K005 QA01 QB01 QC03 RA01 3K065 QC03

Claims (1)

[Claims] 1. A furnace having a plurality of burners,
This is a method for determining the clinker adhesion of a pulverized coal-fired boiler in which a flame detector is provided for each burner, and determines whether or not the clinker is attached to the burner throat based on a detection signal from the flame detector. A method for determining clinker adhesion of a pulverized coal-fired boiler, which comprises determining.