JPH02191785A - Apparatus for controlling char bed form of recovery boiler - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a recovery boiler charbed shape control device used for operational management of a recovery boiler in a pulp manufacturing plant, and in particular to , relates to a char bed shape control device for a recovery boiler that controls the shape, etc.

(Prior Art) Generally, a recovery boiler is used in a pulp manufacturing plant from the viewpoint of energy saving and labor saving. This recovery boiler uses a black liquor injection gun to inject black liquor, which is discharged as waste liquid during the chip cooking process, into the furnace.At this time, the temperature inside the furnace causes the black liquor to float and dry while falling to the bottom of the furnace. Since a char bed is formed, air is sent into the furnace to burn the char bed to generate steam, and the chemical raw material for chip cooking is recovered by the reduction reaction that occurs at that time.

By the way, in recent years, when energy and labor savings are more actively promoted in pulp manufacturing plants, it has become important to maintain the proper shape of the charbed in two positions to ensure stable operation of the recovery boiler and to improve thermal efficiency. It is becoming recognized.

Therefore, in the past, a viewing window was installed in the furnace wall of the recovery boiler, and the operator occasionally patrolled the area around the recovery boiler, monitoring the position and shape of the char bed through the viewing window, and adjusting the amount of black liquor injection and black liquid as necessary. The position and shape of the char bed are controlled by artificially adjusting the liquid temperature, combustion air flow rate, etc. based on past experience.

(Problem to be Solved by the Invention) However, the above char bed shape control means,
Since the temperature of the black liquor injected is adjusted manually, the shape of the char bed cannot be constantly monitored. As a result, for example, the shape of the char bed is too high or steep, causing poor combustion due to collapse of the char bed.
Furthermore, since the shape of the char bed is too low, the recovery efficiency of the chemical raw material for chip cooking is reduced, and there is also a problem of dust carryover. In addition, the method in which the operator monitors the shape of the charbed through the viewing window may cause the charbed to shift to one side or cause local bulges in the charbed if the operator lacks proper attentiveness or the viewing window is somewhat cloudy. Or, the shape of depressions etc. cannot be accurately grasped. As a result, for example, if the position of the char bed is uneven, blackouts may occur due to air injection air port clogging, a large amount of unburned carbon may flow out from the suboutro, or dust welding may occur due to an increase in gas temperature in the recovery boiler. The uneven flow of gas will cause a drop in steam temperature, and if the charbed has a localized bump or depression, there is a risk of combustion fluctuations.Moreover, since it progresses in a short period of time, it is necessary to prevent this phenomenon in advance. It is difficult to understand accurately.

Furthermore, if the char bed collapses or deposits fall from the upper part of the furnace and the side walls of the furnace, the char bed may partially cause combustion failure, so-called blackout. Moreover, if the detection of such an abnormal condition is delayed, prompt recovery measures cannot be taken, and there is a risk that the operation of the plant will be adversely affected.

Therefore, the artificial:jXJ adjustment work is not only labor-intensive, but also makes it difficult to achieve stable plant operation and high efficiency because the shape of the char bed cannot be grasped with high precision.

The present invention has been made to solve the above-mentioned problems, and it is possible to automatically monitor the position and shape of the char bed at all times, and to take appropriate measures quickly in the event of an abnormality in the char bed. It is an object of the present invention to provide a char bed shape control device for a recovery boiler that can achieve stable operation and high efficiency, and that does not pose a risk of interfering with plant operation.

(Means for Solving the Problem) The char bed shape control device for a recovery boiler according to the present invention injects black liquor discharged from the chip cooking process of a pulp manufacturing plant into the furnace using a black liquor injection gun, In a recovery boiler that forms a char bed in a furnace and injects combustion air from multiple locations in the furnace to burn the char bed to generate steam and recover chemical raw materials for chip cooking, the position of the char bed, A char bed shape detection means detects the shape, and control elements that influence the position and shape of the char bed are varied based on the position and shape information of the char bed detected by the char bed shape detection means, and the control elements that influence the position and shape of the char bed are varied to obtain an appropriate char bed. The bed is equipped with data processing control means for changing the position and shape of the bed.

(Function) Therefore, in the present invention, by using the above means, when the position and shape of the char bed is detected by the char bed shape detection means, the position and shape information of the char bed is processed by the data processing flil rJ9 means. By varying the control elements such as the injected black liquor, combustion air, and auxiliary fuel based on this, the proper position and shape of the char bed is always formed, and furthermore, the proper position and shape of the char bed is controlled by feedback. This is to achieve stable operation and high efficiency of the recovery boiler.

(Example) In explaining the example of the device of the present invention, first,
This invention will be explained in detail.

■ The black liquor discharged from the chip cooking process is heated with a black liquor heater and then injected into the furnace with a black liquor injection gun. At that time, the black liquor heater is operated to raise the black liquor temperature to bring it close to the boiling point. In this case, the black liquor injected from the black liquor injection gun dries while floating in the furnace and burns at a high rate, resulting in a decrease in the amount of char bed settling. As a result, the top of the char bed can be lowered. Conversely, if the black liquor temperature is lowered, it will be less likely to burn during suspension, and the top of the char bed can be made higher.

■ Normally, the black liquor injection gun is fixed to the furnace wall, but if you install it so that it can swing and direct the black liquor injection angle upward, or if you increase the injection pressure, the black liquid sprayed from the black liquor injection gun may The liquid floats over a long distance as it descends. As a result, the char bed moves toward the opposing furnace wall, and
Since the floating time is long, the amount of charbed settling is reduced, and as a result, the charbed can be lowered. Conversely, if the angle of the black liquor injection gun is directed downward or the pressure of the black liquor is lowered, the char bed can be brought closer to the furnace wall on the black liquor injection gun side, and the char bed can be made higher.

■ Install black liquor injection guns on the front and opposite furnace walls of the recovery boiler to reduce the amount of black liquor sprayed from the front black liquor injection gun and increase the amount of black liquor sprayed from the opposite black liquor injection gun. The char bed can then be moved to the opposite side wall surface.

(2) Increasing the combustion air flow rate improves combustibility and lowers the char bed. Conversely, if the air flow rate is reduced, combustibility deteriorates and the char bed can be increased.

■ When multiple stages of combustion air inlets are provided in the height direction of the recovery boiler, if the air flow rate injected from the combustion air inlet of the stage corresponding to the top of the charbed is relatively increased, the charbed The combustibility of the top part is improved, so the height of the char bed can be suppressed, and a char bed shape with a flat top part can be created.

■ By relatively increasing the air flow rate injected from the combustion air inlet of the stage corresponding to the bottom side of the char bed, combustion at the bottom of the furnace can be improved and the base of the char bed can be moved away from the furnace wall. , it can be shaped into a steep charbed shape. On the other hand, if the air flow rate injected from the combustion air inlet of the stage corresponding to the bottom of the char bed is relatively reduced, combustion at the bottom of the furnace will deteriorate and the base of the char bed will not be able to be drawn toward the furnace wall. , and can be shaped into a gentle charbed shape.

■ Also, by increasing the amount of air injected from a certain furnace wall side,
When the amount of air injected from the opposing furnace wall side is reduced, combustion becomes more active on the side of the char bed where the amount of air is increased.
Combustion becomes inactive on the side where the amount of air is reduced. As a result, the char bed can be brought closer to the opposing wall surface.

■ The amount of air introduced from one of the first furnace walls facing each other is increased, the amount of air introduced from the other furnace wall is decreased, and the amount of air introduced from the other furnace wall is increased, and If the amount of air introduced from one furnace wall side is decreased as the distance from the one furnace wall increases, that is, the closer to the other furnace wall, the char bed will be moved to the other furnace wall side. I can do it.

■ If the char bed has unevenness, increase the amount of air injected from the combustion air inlet near the convex part to improve combustion in the convex part, and reduce the amount of air injected from the combustion air inlet near the concave part. By improving the combustion of the four parts, the surface of the charbed can be shaped into a smooth state.

[Phase] When heavy oil or the like is assisted in the upper part of the char bed, its radiant heat activates the combustion of the convex portions on the char bed surface, and the char bed surface can be shaped into a clean shape. In addition, since combustion over the entire surface of the char bed improves, the char bed can be lowered overall.

■ By increasing the combustion of the auxiliary burner on a certain wall and decreasing the combustion of the auxiliary burner on the opposite wall, the combustion of the char bed can be activated on the side where there is a lot of combustion, and the char bed can be moved to the opposite wall side. Can be done.

The present invention has been realized based on the above principle, and embodiments thereof will be described below with reference to the drawings.

FIG. 1 is a system configuration diagram showing an embodiment of the present invention. In the same figure, 10 is a recovery boiler that generates and recovers steam and chemical raw materials for chip cooking, and black liquor 11 discharged as waste liquid in the chip cooking process (not shown) is supplied to a black liquor heater 12 and black liquor injection pressure control. Black liquor is injected into the furnace via a valve 13 by a black liquor injection gun 14. The black liquor sprayed by the black liquor spray gun 14 is suspended and dried, and then lands on the bed, thereby forming a char bed 15. Therefore, in this black liquor supply system, the black liquor 11 from the chip cooking process is heated to a desired temperature by the black liquor heater 12, and is adjusted to a desired pressure or flow rate by the black liquor injection pressure control valve 13. Further, black liquor is injected from the black liquor injection gun 14 at a desired injection angle by means of a gun angle control valve 16.

17 is a heating medium, and 18 is a black liquor temperature control valve.

Although only one black liquor injection gun 14 is shown in the figure, a plurality of black liquor injection guns 14 are normally provided at different positions on the furnace wall.

The recovery boiler IO is provided with a combustion air supply system. This combustion air supply system is provided with combustion air inlets 21a, 21b, and 21c in multiple stages in the vertical direction of the furnace wall, and each stage has multiple combustion air inlets in the horizontal direction as shown in the lower part of the figure. Combustion air inlet 21a,...
21b, . . . 21c, -= (21b, 21c are not shown) are provided. That is, these plurality of combustion air inlets are each grouped into a plurality of units, and a combustion air operating means 22 is provided for each group. The combustion air operating means 22 has the function of injecting the combustion air 23 into the furnace and burning the char bed 15 while appropriately distributing and adjusting the air flow rate of the combustion air 23 to each combustion air input port.

Furthermore, the recovery boiler 10 is provided with an auxiliary fuel supply system. In this auxiliary combustion fuel supply system, an auxiliary combustion burner 31 is attached to the furnace wall of the recovery boiler 10, and an auxiliary combustion fuel 32 such as heavy oil is supplied to the auxiliary combustion burner 31 via an auxiliary combustion operation valve 33.

40 is, for example, an ITV camera or a scanning bicamera 9 (1
) A char bed shape detecting means 4o that detects a char bed position/shape signal a.
is output. Note that this char bed shape detection means 4
A plurality of units o can be installed on the same wall surface or on multiple wall surfaces as necessary.

Reference numeral 50 denotes a data processing control means for obtaining an operational output for obtaining the char bed 15 in an appropriate position and shape based on the char bed position/shape signal aI sent from the char bed shape detection means 4o.

Specifically, this data processing control means 50 is composed of a CPU that executes predetermined processing based on program data, a memory, an input/output interface, etc., and functionally, as shown in FIG. A/D conversion means 51 for converting the shape signal a into digital image data. The measured image data converted by this A/D conversion means 51 is
Measured image data storage means 52 for storing dimensionally, standard image data storage means 53 for storing at least one patterned standard image data, and these storage means 52.5.
Comparing the measured image data of 3 with the standard image data, the actual NJ
Determine whether the char bed of the il image data is higher or lower than the char bed of the standard image data, or whether it is biased in any direction, and if necessary, whether it is uneven. An image comparison/determination means 54 outputs an operation control signal based on the determination result;
8.33 and a command signal generating means 55b for selecting the operating means 16.22 and outputting a command signal.

Next, the operation of the apparatus configured as above will be explained.

The black liquor 11 discharged from the chip cooking process is passed through the black liquor heater 1.
2, the black liquor injection pressure control valve 13 sets the required pressure or flow rate, and the gun angle control means 16 injects the black liquid into the furnace at a desired injection angle. At this time, the injected black liquor in the furnace floats and dries and settles on the bottom of the furnace, forming a char bed 15 as shown in FIG. At this time, using the combustion air operating means 22, the combustion air input port 21g
, 21b, 21c at the required flow rate of combustion air 23.
When supplied, steam is generated by combustion of the char bed 15, and the chemical raw material for chip cooking can be recovered by the reduction reaction that occurs at that time.

During combustion of the char bed 15, one or more char bed shape detection means 40 captures a position/shape signal a of the char bed 15 within the measurement field of view, and then sends it to the data processing control means 50. In this data processing control means 50, the char bed position/shape signal a from the char bed shape detection means 40 is transferred to the A/D conversion means 51.
By digitally converting the data and storing it in the measured image data storage means 52, for example, two-dimensional measured image data (a) as shown in Fig. m3 (a) is obtained.

Thereafter, the data processing control means 50 executes operations as shown in FIG. 4, for example, based on the program data. That is, as shown in step S1, it is determined whether or not it is the image matching time, and when it is determined that it is the image matching time, the image matching determining means 54 stores the measured image data (a) stored in the actual AFJ image data storage means 52. and the standard image data (b) in the standard image data storage means 53.

That is, in step S2, it is determined whether the shape of the char bed 15 is too high. Now, assuming that the data in the dotted line part of FIG. Command signal generating means 55b.

A command No. 1J for increasing the set value of the black liquor temperature and a command signal for increasing the air flow rate at the top of the char bed are sent to 55e, respectively. As a result, this command signal generating means 55
From b is the operation output that increases the valve opening degree, but the black liquor temperature control valve 1
Therefore, the black liquor heater 12 is controlled to raise the temperature of the black liquor 11 (see principle 0 above). Also,
A signal e for increasing the air flow rate at the top of the char bed is sent from the command signal generating means 55e to the combustion air operating means 22. Here, the combustion air operating means 22 controls so as to send a larger amount of air flow out of the total air flow rate of the combustion air 23 to the combustion air input port 21a near the top of the char bed than to the lower combustion air input port, for example, 21c. do. Figure 3 (a
) arrow (c) indicates this state. As a result, as described in Principle 0 above, combustion at the top of the char bed improves, and the char bed 15 is shaped into a shape close to the standard image data (b) shown by the dotted line in FIG. 3(a).

Further, when it is determined in step S2 that the shape of the char bed 15 is low, the process moves to step S5 and it is determined whether the char bed 15 is too low. JI cuts. f! 4
For example, as shown in FIG. 3(b), if the measured image data (a) is too low than the standard image data (b), step 86.
In S7, control opposite to that described above is performed.

When it is determined in step S5 that the char bed 15 is not too low, the process proceeds to step S8, where it is determined whether the char bed 15 is biased to the right side,
If it is biased to the right side, the command signal generating means 55e sends a control signal e to the combustion air operating means 22 to increase the air flow rate of the right side combustion air inlet. Here, the combustion air operating means 22 increases the air flow rate of the right side combustion air inlet (see principle 0 above).

Furthermore, in step S8, the char bed 15
When it is determined that the position is biased to the left as shown in FIG.
11. (See Principle 0 above).

Furthermore, when actually measured image data (a) as shown in FIG. 3(d) is obtained, if control is performed based on the principle 0 term, the ! SS (both image data ports) can be moved to the side.

Therefore, according to the configuration of the embodiment as described above, the char bed shape detection means 40 is provided on the furnace wall of the recovery boiler 10,
The actual J? obtained from this char bed shape detection means 40?
J image data and standard image data are compared to determine the shape and positional deviation of the char bed 15, and based on the determination results, various control elements that affect the position and shape of the char bed 15 are operated and feedback is provided. Since the configuration is such that the char bed 15 is corrected to an appropriate shape and position using a control system, adverse effects such as poor combustion due to collapse of the char bed, a decrease in the recovery rate of the chemical raw material for chives cooking, and an increase in carryover can be avoided. Not only is this possible, but since the shape of the char bed is automatically controlled, even if an abnormality occurs in the char bed, it can be quickly changed to the desired shape. Therefore, there is no risk of interfering with the operation of the plant, and stable operation and high efficiency of the recovery boiler can be achieved, and further energy and labor savings can be achieved.

It goes without saying that the present invention is not limited to the control elements shown in FIG. In addition, the present invention can be implemented with various modifications without departing from the gist thereof.

(Effects of the Invention) As described in detail above, according to the present invention, the recovery boiler is provided with a charbed shape detection means, and the position and shape of the charbed are determined based on the actually measured image data obtained by the charbed shape detection means. By controlling the control elements that affect the char bed, the position and shape of the char bed can be automatically monitored at all times, and appropriate measures can be taken quickly in the event of an abnormality in the char bed, thereby ensuring stable operation of the recovery boiler and It is possible to provide a char bed shape control device for a recovery boiler that contributes to high efficiency and can reliably achieve energy and labor savings.

[Brief explanation of the drawing]

1 to 4 are shown to explain an embodiment of the char bed shape control device for a recovery boiler according to the present invention, and FIG. 1 is a system diagram showing the configuration of the device of the present invention, and FIG. The figure is a functional block diagram of the data processing control means in Figure 1,
FIG. 3 is a diagram showing an example of control based on the deviation between measured image data and standard image data, and FIG. 4 is a flowchart explaining the operation of the apparatus of the present invention. DESCRIPTION OF SYMBOLS 10... Recovery boiler, 11... Black liquor, 12... Black liquor heater, 13... Black liquor injection pressure control valve, 14...
Black liquor injection gun, 15...Char bed, 16...Gun angle operating means, 21a, 21b, 21c...Combustion air inlet, 22...Combustion air operating means, 23...Combustion air , 31... auxiliary combustion burner, 32... auxiliary combustion fuel, 33... auxiliary combustion operation valve, 40... char bed shape detection means, 52... actually measured image data storage means, 53.
. . . Standard image data storage means, 54 .

Claims (4)

[Claims] (1) Black liquor discharged from the chip cooking process of a pulp manufacturing plant is injected into the furnace using a black liquor injection gun to form a char bed at the bottom of the furnace, and combustion air is injected into multiple locations within the furnace. In a recovery boiler that generates steam by burning the char bed and recovers chemical raw materials for chip cooking, the char bed shape detection means detects the position and shape of the char bed, and the char bed shape detection means detects the position and shape of the char bed. and a data processing control means for changing control elements that influence the position and shape of the char bed to an appropriate char bed position and shape based on the char bed position and shape data. Char bed shape control device for recovery boiler. (2) Claim (1), wherein the control element is at least one of the injected black liquor, the combustion air, and the auxiliary fuel.
A char bed shape control device for a recovery boiler as described in 2. (3) The data processing control means compares the char bed position/shape data detected by the char bed shape detection means with predetermined standard data, and varies the control element according to the position/shape deviation of both data. A char bed shape control device for a recovery boiler according to claim (1). (4) Variable control elements include the black liquor injection angle of the black liquor injection gun, the temperature of the black liquor to be injected, the pressure of the black liquor to be injected, the flow rate distribution ratio of the black liquor injected from multiple locations, and the flow rate distribution ratio of the black liquor injected from multiple locations. Claim No. 1, wherein one or more of the input flow rate and the air flow rate ratio of combustion air at a plurality of locations are varied
) A char bed shape control device for a recovery boiler as described in item 2.