JPH076152B2 - Char bed shape controller for recovery boiler - Google Patents

Description

TECHNICAL FIELD The present invention relates to a char bed shape control device for a recovery boiler used for operation management of a recovery boiler in a pulp manufacturing plant, and particularly to a char bed for a recovery boiler. The present invention relates to a char bed shape control device for a recovery boiler that controls the position, shape, etc.

(Prior Art) Generally, in a pulp manufacturing plant, a recovery boiler is used from the viewpoint of energy saving and labor saving. This recovery boiler injects black liquor discharged as waste liquor in the chip digestion process into the furnace using a black liquor injection gun, at which time the temperature of the furnace causes the black liquor to float and dry and to fall to the bottom of the furnace. Since a char bed is formed, air is sent into the furnace to combust the char bed to generate steam, and a reducing reaction generated at that time recovers the chemical raw material for chip cooking.

By the way, in recent years, when more aggressively promoting energy saving and labor saving in a pulp manufacturing plant, it is important to maintain an appropriate shape and position of the char bed to achieve stable operation of the recovery boiler and improvement of thermal efficiency. Has been recognized.

Therefore, conventionally, a peep window was provided on the furnace wall of the recovery boiler, and the operator occasionally circulates around the recovery boiler to monitor the position and shape of the char bed from the peep window, and if necessary, the black liquor injection amount and black The position and shape of the char bed are controlled while artificially adjusting the liquid temperature and the flow rate of combustion air based on past experience.

(Problems to be Solved by the Invention) However, the above-mentioned charbed shape control means is
Since the temperature of the black liquor to be jetted is manually adjusted, 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 the char bed collapses due to its steepness, causing combustion failure,
Further, since the shape of the char bed is too low, the recovery efficiency of the chemical raw material for chip digestion is reduced, and there is a problem that dust carryover occurs. In addition, the method in which the operator monitors the shape of the char bed through the peep window does not allow proper attention, or the peep window is slightly cloudy. Or it is not possible to accurately grasp the shape of depressions.
As a result, for example, when the position of the char bed is offset, blackout occurs due to an air port clogging for air injection, a large amount of unburned carbon flows out from the spoutro, or dust deposition due to an increase in the gas temperature in the recovery boiler. In addition, if the charbed has a shape such as a local ridge or depression, there is a risk of combustion fluctuations. It is difficult to grasp accurately.

Further, when the char bed collapses or the deposits fall from the upper part of the furnace and the side wall of the furnace, the char bed partially causes poor combustion, so-called blackout. Moreover, if the detection of such an abnormal state is delayed, rapid recovery processing cannot be performed, and there is a risk of adversely affecting the operation of the plant.

Therefore, the manual adjustment work is not only labor-intensive, but also it is difficult to grasp the shape of the char bed with high precision, and thus it is difficult to achieve stable plant operation and high efficiency.

The present invention has been made to solve the above problems, and can always automatically and automatically monitor the position and shape of the char bed, and can take appropriate measures promptly when the char bed is abnormal. 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 hinder plant operation.

(Means for Solving the Problem) A char bed shape control device for a recovery boiler according to the present invention is to inject black liquor discharged from a chip digesting step of a pulp manufacturing plant into a furnace with a black liquor injection gun to form a furnace bottom portion. In the recovery boiler to form a char bed and to generate steam by injecting combustion air from multiple points in the furnace to combust the char bed and to recover the chip cooking chemical raw material, on the furnace wall of the recovery boiler. A black liquor supply system in which the black liquor injection gun is attached via a gun angle operation unit, and the black liquor from the chip cooking step is applied to the black liquor injection gun through a black liquor temperature control unit and a pressure operation unit. , The char bed shape detecting means for detecting the position and shape of the char bed, and the char bed position / shape data detected by the char bed shape detecting means. Based on the black liquor spray angle of the black liquor spray gun, the temperature of the black liquor to be sprayed, the pressure of the black liquor to be sprayed, and the flow distribution ratio of the black liquor to be sprayed from multiple locations, Data processing control means for changing any one or more and changing the position and shape of the char bed to an appropriate value are provided.

(Operation) Therefore, according to the present invention, when the charbed shape detecting means detects the position and shape of the charbed, the data processing control means detects the position and shape of the charbed based on the position and shape information of the charbed. By changing any one or more of 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, and the flow distribution ratio of the black liquor to be injected from multiple locations, The proper position and shape of the char bed are formed, and the proper position and shape of the char bed are maintained by feedback control to achieve stable operation and high efficiency of the recovery boiler.

(Example) Hereinafter, in describing an example of the device of the present invention, first,
The principle of the present invention will be described.

When the black liquor discharged from the chip cooking process is heated by the black liquor heater and then injected into the furnace by the black liquor injection gun, when the black liquor heater is operated to raise the temperature of the black liquor to bring it close to the boiling point. The black liquor injected from the black liquor injection gun has a higher rate of drying and burning while floating in the furnace, and the amount of landing on the char bed decreases. As a result, the top of the char bed can be lowered. On the contrary, if the temperature of black liquor is lowered, it becomes difficult to burn while floating, and the top of the char bed can be raised.

Normally, the black liquor injection gun is fixed to the furnace wall, but for example, if the black liquor injection gun is installed so that it can swing and the black liquor injection angle is directed upwards or the injection pressure is increased, the black liquor injection gun is injected Descends while floating far away. As a result, the char bed moves to the opposite furnace wall side, and
Since the floating time is long, the landing amount of the char bed is reduced, and as a result, the char bed can be lowered. On the contrary, when 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 raised.

Attach black liquor injection guns to the front and counter furnace walls of the recovery boiler to reduce the black liquor injection amount of the front side black liquor injection gun and increase the black liquor injection amount of the opposite side black liquor injection gun. Then, the char bed can be moved to the opposite side wall surface.

As the flow rate of combustion air is increased, the combustibility is improved and the char bed can be lowered. Conversely, if the air flow rate is reduced, the 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 flow rate of air injected from the combustion air inlet of the stage corresponding to the top of the char bed is relatively increased, The combustibility of the portion is improved, so that the height of the char bed can be suppressed, and the shape of the char bed having a flat top can be formed.

When the flow rate of the air introduced from the combustion air inlet of the stage corresponding to the bottom side of the char bed is relatively increased, the combustion at the bottom of the furnace is improved and the skirt of the charbed can be separated from the furnace wall, and It can be shaped into a steep charbed. On the contrary, if the flow rate of the air injected from the combustion air inlet of the stage on the side corresponding to the bottom of the char bed is relatively decreased, the combustion at the bottom of the furnace becomes worse and the skirt of the char bed can be drawn to the furnace wall. And, it can be shaped into a gentle char bed.

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

Of the first furnace walls facing each other, the amount of air introduced from one furnace wall is increased, the amount of air introduced from the other furnace wall is decreased, and further, the first furnace wall on the side orthogonal to the first furnace wall. As the amount of air introduced from the furnace wall side of the furnace becomes smaller as it moves away from the one furnace wall, that is, as it approaches the other furnace wall, the char bed can be moved to the other furnace wall side. it can.

If the char bed is uneven, increase the amount of air injected from the combustion air input port near the convex part to improve the combustion of the convex part, and decrease the flow rate of air injected from the combustion air input port near the concave part to reduce the concave part. By deteriorating the combustion of the char bed, the charbed surface can be shaped into a smooth state.

When the heavy oil or the like is additionally burned in the upper portion of the char bed, the radiation heat activates burning of the convex portion on the surface of the char bed, and the char bed surface can be shaped into a smooth shape. Further, since the combustion of the entire char bed is improved, the char bed can be lowered as a whole.

By increasing the combustion of the auxiliary combustion burner on a specific wall surface and decreasing the combustion of the auxiliary combustion burner on the opposite wall surface, it is possible to activate the combustion of the char bed on the side with the most combustion and move the char bed to the opposite wall side. it can.

The present invention has been realized on the basis of the above principle, and an embodiment 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 figure, 10 is a recovery boiler for producing and recovering steam and chemical raw materials for chip digestion, in which a black liquor 11 discharged as a waste liquid in a chip digesting step (not shown) is a black liquor heater.
Black liquor injection gun 14 via 12 and black liquor injection pressure control valve 13
Is injected into the furnace by. The black liquor sprayed by the black liquor spray gun 14 is float-dried and landed to form a char bed 15. Therefore, in this black liquor supply system, the black liquor 11 from the chip cooking step 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 operating valve 13. Also gun angle control valve
The black liquor injection gun 14 injects 16 at a desired injection angle. Reference numeral 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 usually provided on the furnace wall at different positions.

The recovery boiler 10 is provided with a combustion air supply system. This combustion air supply system is provided with combustion air inlets 21a, 21b, 21c in a plurality of stages in the vertical direction of the furnace wall, and as shown in the lower side of FIG. Combustion air inlets 21a, ..., 21b, ..., 21c, ... (21b, 21
c is not shown). That is, the plurality of combustion air inlets are grouped in a plurality of units, and the combustion air operating means 22 is provided for each group. The combustion air operating means 22 has a function of charging the combustion air 23 into the furnace while appropriately adjusting the flow rate of the combustion air 23 to each combustion air charging port and burning the char bed 15.

Further, 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 auxiliary combustion fuel 32 such as heavy oil is supplied to the auxiliary combustion burner 31 via an auxiliary combustion operation valve 33.

Reference numeral 40 denotes a charbed shape detecting means such as an ITV camera or a scanning pyrometer, and the charbed shape detecting means 40 outputs a charbed position / shape signal a. It should be noted that a plurality of the char bed shape detecting means 40 are mounted on the same wall surface or a plurality of wall surfaces as required.

Reference numeral 50 is a data processing control means for obtaining an operation output for obtaining the charbed 15 at an appropriate position / shape based on the charbed position / shape signal a sent from the charbed shape detection means 40. The data processing control means 50 is specifically composed of a CPU that executes a predetermined process based on program data, a memory, an input / output interface, and the like. Functionally, as shown in FIG. A / D conversion means 51 for converting the shape signal a into digital image data, actual measurement image data storage means 52 for two-dimensionally storing the actual measurement image data converted by the A / D conversion means 51, and at least patterned Standard image data storage means 53 for storing one piece of standard image data, and these storage means 52, 53
Of the measured image data and the standard image data are compared to determine whether the charbed of the measured image data is higher or lower than the charbed of the standard image data, or in which direction it is biased, and if necessary, unevenness Image collation judging means 54 for judging whether or not it is in a state and outputting an operation control signal based on the judgment result, and this image collation judging means
Based on the output of 54, one of the operation valves 13, 18, 33 and the operation means 16, 22 is selected, and the command signal generation means 55b for outputting a command signal is configured.

Next, the operation of the apparatus configured as described above will be described.
The black liquor 11 discharged from the chip cooking process is heated by the black liquor heater 12, and then set to the required pressure or flow rate by the black liquor injection pressure control valve 13, and further the required injection by the gun angle control means 16. It is injected into the furnace at an angle. At this time, the jetted black liquor in the furnace is floating-dried and is landed on the bottom of the furnace, and the char bed 15 as shown in FIG. 1 is formed. At this time, when the combustion air 23 is supplied from the combustion air input ports 21a, 21b, 21c using the combustion air operation means 22, a required amount of combustion air 23 is generated by the combustion of the char bed 15, and at that time. The chemical reaction for chip digestion can be recovered by the resulting reduction reaction.

At the time of burning of the char bed 15, one or a plurality of char bed shape detecting means 40 captures an image of the position / shape signal a of the char bed 15 in the measurement visual field, and then sends it to the data processing control means 50. In the data processing control means 50, the charbed position / shape signal a from the charbed shape detection means 40 is digitally converted by the A / D conversion means 51 and stored in the actually measured image data storage means 52. Two-dimensional measured image data (a) as shown in FIG. 3 (a) is acquired.

Thereafter, the data processing control means 50 executes the operation 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 measured image data stored in the measured image data storage means 52 by the image matching determination means 54 The standard image data (53) in the standard image data storage means 53 is compared. 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 portion in FIG. 3 (a) is the two-dimensional standard image data (b), since the shape of the char bed 15 is high as apparent from the figure, the process proceeds to steps S3 and S4. A command signal 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 the command signal generating means 55b, 55e, respectively. As a result, the operation output b for increasing the valve opening is sent from the command signal generating means 55b to the black liquor temperature control valve 18, and the black liquor heater 12 is controlled to raise the temperature of the black liquor 11 (the above-mentioned principle). See section). Also, the command signal generating means 55e
A signal e for increasing the air flow rate at the top of the char bed is sent to the combustion air manipulating means 22. Here, the combustion air operating means 22 is controlled so as to send a larger amount of air flow than the lower combustion air inlet 21a, for example, to the combustion air inlet 21a near the top of the char bed, out of the total air flow of the combustion air 23. To do. The arrow (c) in FIG. 3 (a) shows this state. As a result, the combustion at the top of the char bed is improved as described in the above principle, 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).

When it is determined that the shape of the char bed 15 is low in step S2, the process proceeds to step S5 and it is determined whether the char bed 15 is too low. For example, FIG. 3 (b)
When the actually measured image data (a) is too lower than the actually measured image data (b) as shown in, the control opposite to the above is performed in steps S6 and S7.

When it is determined in step S5 that the char bed 15 is not too low, the process proceeds to step S8, in which it is determined whether the char bed 15 is offset to the right side, and if it is offset to the right side, a command signal is generated. A control signal e for increasing the air flow rate at the right side combustion air inlet is sent from the means 55e to the combustion air operating means 22. Here, the combustion air operating means 22 increases the air flow rate at the right combustion air inlet (see the above-mentioned principle).

Further, when it is determined in step S8 that the char bed 15 is offset to the left as shown in (c) of FIG. 4, the control opposite to the step S9 is performed (step S11,
(Refer to the above principle).

Further, when the measured image data (a) as shown in FIG. 3 (d) is obtained, it can be moved to the side of the standard image data (b) indicated by the dotted line by controlling based on the principle term.

Therefore, according to the configuration of the above embodiment, the charbed shape detecting means 40 is provided on the furnace wall of the recovery boiler 10, and the measured image data and the standard image data obtained from the charbed shape detecting means 40 are collected. Determine the shape and position shift of the char bed 15 while making comparisons, operate various control elements that affect the position and shape of the char bed 15 based on the result of the judgment, and adjust the char bed 15 appropriately by the feedback control method. Since the structure and position are corrected, not only adverse effects such as combustion failure due to collapse of the char bed, reduction of recovery rate of chemical raw material for chip digestion, increase of carry-over, etc. can be avoided, but also these char beds can be avoided. Since the shape control is automatically performed, it is possible to quickly change the shape to a desired shape even if an abnormality occurs in the char bed. Therefore, the operation of the plant is not hindered, stable operation of the recovery boiler and high efficiency can be achieved, and further energy saving and labor saving can be achieved.

Needless to say, the present invention is not limited to the control element shown in FIG. In addition, the present invention can be modified in various ways without departing from the scope of the invention.

(Effects of the Invention) As described in detail above, according to the present invention, a char bed shape detecting means is provided in the recovery boiler, and the position and shape of the char bed are determined based on the measured image data obtained by the char bed shape detecting means. The position and shape of the char bed can be automatically monitored at all times by controlling the control elements that affect the operation of the char bed, and appropriate measures can be taken promptly when the char bed is abnormal, thus 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 higher efficiency and can reliably realize energy saving and labor saving.

[Brief description of drawings]

1 to 4 are shown for explaining one embodiment of a char bed shape control device for a recovery boiler according to the present invention, and FIG. 1 is a system diagram showing a configuration of the present invention device, and FIG. The figure is a functional block diagram of the data processing control means of FIG.
FIG. 3 is a diagram showing an example of control due to a shift between the actually measured image data and the standard image data, and FIG. 4 is a flow chart for explaining the operation of the device of the present invention. 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 control means, 21a, 21b, 21c
...... Combustion air inlet, 22 ...... Combustion air operating means, 23 ......
Combustion air, 31 ... auxiliary burner, 32 ... auxiliary fuel, 33 ...
… Auxiliary combustion control valve, 40… Char bed shape detection means, 52…
... actually measured image data storage means, 53 ... standard image data storage means, 54 ... image collation determination means, 55b to 55f ... command signal generation means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yohei Shioshikoshi 1-chome, 1-chome, Jujo-cho, Yatsushiro-shi, Kumamoto Pref. At the Yatsushiro Mill, Tojo Paper Manufacturing Co., Ltd. (72) Takao Matsuda 2-4-2-5 Minamisuna, Koto-ku, Tokyo Kawasaki Heavy Industries Ltd. Tokyo Design Office (72) Inventor Toshiyuki Idoko 1-1 Kawasaki-cho, Akashi-shi, Hyogo Prefecture Kawasaki Heavy Industries Ltd. Akashi-plant (72) Inventor Shiro Nakabayashi 1-Kawasaki-cho, Akashi-shi, Hyogo Prefecture No. 1 Kawasaki Heavy Industries Ltd., Akashi Plant (72) Inventor Kazuyuki Iizuka 1-1-1, Shibaura, Minato-ku, Tokyo Toshiba Head Office Co., Ltd. (72) Inventor Ryuichi Kuwata No. 1 Toshiba-cho, Fuchu, Tokyo Inside the Toshiba Fuchu Factory (72) Inventor Ao Kumaki 1 Toshiba Town, Fuchu City, Tokyo Inside the Fuchu Factory, Toshiba Corporation (72) Inventor Atsushi Muramatsu Tokyo (1) No. 1 Toshiba-cho, Fuchu-shi Toshiba Corporation Fuchu factory (56) References JP-A-62-129601 (JP, A) JP-A-61-49903 (JP, A) JP-A-62-29828 (JP, A) JP 62-29803 (JP, A) JP 52-17346 (JP, B2)

Claims (1)

[Claims] 1. A black liquor discharged from a chip cooking process of a pulp manufacturing plant is injected into a furnace by a black liquor injection gun to form a char bed at the bottom of the furnace, and combustion air is introduced into a plurality of places in the furnace. Then, in the recovery boiler that generates the steam by burning the char bed and recovers the chemical raw material for chip digestion, the black liquor injection gun is attached to the furnace wall of the recovery boiler via the gun angle operation unit, A black liquor supply system in which the black liquor from the chip cooking step is applied to the black liquor injection gun through a black liquor temperature control unit and a pressure operation unit, and a char bed shape detecting means for detecting the position and shape of the char bed. And a black liquor injection gas that influences the position and shape of the char bed based on the char bed position / shape data detected by the char bed shape detecting means. The proper position and shape of the char bed by changing any one or more of the black liquor jetting angle, the temperature of the jetting black liquor, the pressure of the jetting black liquor, and the flow distribution ratio of the black liquor jetting from multiple locations A char bed shape control device for a recovery boiler, comprising: