JP3538925B2 - Drive control unit for coal-fired boiler ash processing unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for a coal-fired boiler ash processing device.

[0002]

4 to 6 show an example of a conventional coal-fired boiler 1. The coal-fired boiler 1 is composed of a furnace 2 and a rear heat transfer unit 3, and the furnace A plurality of burners 4 are provided at the lower part of the front and rear walls 2 a of the furnace 2, and a suspended heat transfer tube 5 is provided inside the furnace 2.

The right and left side walls 2b of the furnace 2 are provided with burners 4
A plurality of furnace soot blowers 6 for removing ash (clinker) C adhered and deposited on the left and right front and rear inner walls 2a and 2b of the furnace 2 and the hanging heat transfer tubes 5 and the like by the combustion of the furnace 2 When the soot blower 6 is at rest,
In the ash blowing operation, the ash C is removed by projecting into the furnace 2 and ejecting steam as shown by a broken line during the ash blowing operation.

[0004] Each of the furnace soot blowers 6 has a structure shown in FIG.
The soot blower operation signal 9 from the soot blower control device 8 to which the program command 7 has been input is input as shown in FIG. 5, and when it is necessary to remove the ash C in the furnace 2 (generally, every predetermined time) All furnace furnace soot blowers 6 are sequentially operated by a soot blower operation signal 9 output so as to operate in a predetermined order according to a program command 7).

As shown in FIGS. 5 and 6, a seal chute 10 having a narrow width in the front-rear direction and a long length in the left-right direction is attached to the lower end of the furnace 2. The high-temperature ash C that has been inserted into the ash cooling water tank 12 that is elongated in the left-right direction and that has been stretched in the left and right direction and that has been dropped from the furnace 2 is sealed in the outside with the water 11 in the ash cooling water tank 12. The ash treatment device 14 is configured so that the ash C is dropped into the ash cooling water tank 12 for extinguishing and cooling, and further includes a scraper conveyor 13 for scraping out the ash C dropped into the ash cooling water tank 12 to the outside of the ash cooling water tank 12. Have been.

The ash cooling water tank 12 is provided with an intermediate bottom plate 15, and at both left and right end portions of the intermediate bottom plate 15, a folded side inclined portion 15a and a discharge side inclined portion 15b which are inclined upward as shown in FIG. And the inclined portions 15a, 15
As shown in FIG. 6, a pair of front and rear chain wheels 16, 16 ', 17, 17' are provided at respective end positions of b.

The scraper conveyor 13 includes a chain 18 extending between the front chain wheels 16 and 17, a chain 18 'extending between the rear chain wheels 16' and 17 ', and a chain 18 and 18'. And a plate-shaped scraper 19 attached at a required interval in the longitudinal direction of the chains 18 and 18 ′. The scraper side of the scraper conveyor 13 moves in the direction of the arrow along the upper surface of the intermediate bottom plate 15. The return side is arranged so as to move below the intermediate bottom plate 15. Reference numeral 20 denotes a chain support wheel.

Further, an ash discharge port 21 is provided below the end of the discharge side inclined portion 15b, and a constant speed motor 22 which rotates at a constant speed by a gear system is provided on the chain wheels 17, 17 '. Installed.

In the coal-fired boiler 1, the burner 4
When the operation due to the combustion is continued, ash (clinker) C due to the combustion is deposited on the left and right inner walls 2a and 2b of the furnace 2 and the suspended heat transfer tube 5 and the like. In order to remove the ash C without affecting the combustion of the furnace 2,
According to a soot blower operation signal 9 from a soot blower control device 8 in which the order of operation is determined in advance by a program command 7, the furnace soot blowers 6 are sequentially operated to inject steam to remove the above-mentioned ash C, and all the furnace soot blowers are used. 6
The operation of the furnace soot blower 6 is terminated by completing the operation of the furnace soot in several hours.

The ash C removed from the furnace 2 by the furnace soot blower 6 falls into the ash cooling water tank 12 below and
Cooled by 1. The cooled ash C is supplied to the constant speed motor 2
5, the scraper 19 of the scraper conveyor 13 driven at a constant speed in the direction of the arrow in FIG.

[0011]

However, the above-described drive control apparatus for the conventional coal-fired boiler ash processing apparatus has the following various problems.

Generally, when the furnace soot blower 6 is operated, a larger amount of ash C falls into the ash cooling water tank 12 than when the furnace soot blower 6 is not operated. Has a scraper conveyor 1
As a result, the ash C is accumulated in the seal chute 10 and the scraper conveyor 13 is overloaded, so that the constant speed motor 22 trips. When the ash C accumulates in the seal chute 10 as described above, the seal chute 10
If the seal chute 10 breaks, for example, the seal chute 10 may be damaged, causing a problem that the coal-fired boiler 1 must be stopped because the seal cannot be maintained.

If a large amount of ash C accumulates in the ash cooling water tank 12, the lightweight ash C and water 11 are removed from the ash cooling water tank 12.
Has a problem of overflow from the upper side 12a.

[0014] As means for solving these problems,
It is conceivable that the scraper conveyor 13 is driven to rotate at a high speed by the constant speed motor 22, but if the scraper conveyor 13 is always rotated at a high speed, the chain 18
The scraper 19 'and the scraper 19 wear significantly, causing a problem that the life of the scraper conveyor 13 is greatly shortened, and a problem that power consumption is increased.

The present invention has been made in view of such circumstances, and prevents ash falling from a furnace into an ash cooling water tank from accumulating in a seal chute, and at the same time, reduces wear and power consumption of a scraper conveyor. It is an object of the present invention to provide a drive control device for a coal-fired boiler ash processing device that can perform the above-described operations.

[0016]

According to the present invention, a seal chute is attached to a lower part of a furnace of a coal-fired boiler having a plurality of furnace soot blowers, and the lower end of the seal chute is inserted into an ash cooling water tank filled with water. And a drive control device for a coal-fired boiler ash treatment device including a scraper conveyor for scraping ash dropped into the ash cooling water tank from the furnace through the seal chute to the outside of the ash cooling water tank , wherein the scraper conveyor has a Variable drive to change scraping speed
Speed motor and speed for controlling the operating speed of the variable speed motor
And a switching control device, the speed switching control device, during operation of the furnace sootblower outputs a high-speed operation signal to the variable speed motor scraper conveyor, a predetermined time has elapsed the operation of the furnace sootblower is due to the delay timer when finished to output a low-speed operation signal to the variable speed motor after
And a drive control device for a coal-fired boiler ash treatment device.

[0017]

According to the present invention, when the operation of the furnace soot blower is started, the speed switching control device immediately outputs a high speed operation signal to the variable speed motor, and the scraper conveyor operates at a high speed. Therefore, even if a large amount of ash falls into the ash cooling water tank by the operation of the furnace soot blower, the ash is smoothly discharged to the outside without being accumulated in the seal chute by the scraper conveyor operated at high speed. Become.

When the operation of all the furnace soot blowers is completed, the speed switching control device outputs a low speed operation signal to the variable speed motor after the time set in the delay timer has elapsed,
The scraper conveyor will be operated at low speed. Thereby, the operation is switched so that the operation of the scraper conveyor is switched to a low speed after a large amount of ash dropped into the ash cooling water tank by the operation of the furnace soot blower is discharged to the outside.

[0019]

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

FIG. 1 shows an embodiment of the present invention applied to the conventional coal-fired boiler ash treatment apparatus shown in FIGS. 4 and 5. In the drawings, the same reference numerals denote the same parts. It represents.

As shown in FIG. 1, a seal chute 10 is attached to a lower part of a furnace 2 of a coal-fired boiler 1 provided with a plurality of furnace soot blowers 6, and a lower end of the seal chute 10 is filled with water 11 in an ash cooling water tank. 12 and the furnace 2
Ash C that has fallen into the ash cooling water tank 12 from the ash cooling water tank 12
In the ash processing device 14 of the coal-fired boiler 1 provided with a scraper conveyor 13 for scraping out, the chain wheels 17, 17 'of the scraper conveyor 13
A variable speed motor 23 capable of changing the scraping speed is connected and arranged.

A soot blower operation signal 9 of a soot blower control device 8 for controlling the operation of the furnace soot blower 6 is inputted. During the operation of the furnace soot blower 6, a high speed operation signal 24 is outputted to the variable speed motor 23 of the scraper conveyor 13. After the operation of the furnace soot blower 6 is completed, a speed switching control device 26 for outputting a low speed operation signal 25 to the variable speed motor 23 after a predetermined time has elapsed is provided.

As shown in FIG. 2, when the soot blower operation signal 9 of the soot blower control device 8 is input, the speed switching control device 26 outputs the high speed operation signal to the variable speed motor 23.
The soot blower operation signal 9 is inputted, and the output is O (zero) while the soot blower operation signal 9 is inputted. To output 1 when the soot blower operation signal 9 is no longer input
A delay circuit 29 for receiving an output from the NOT circuit 28 and outputting the output after a lapse of a predetermined time; and a scraper conveyor for continuously outputting the low-speed operation signal 25 to the variable speed motor 23 when the output of the delay timer 29 is input. And a low-speed operation command device 30. Furthermore, high-speed operation signal 2
4 and a low-speed operation signal 25, a switching circuit 35 for outputting a newly output signal to the variable speed motor 23 with priority.

In the case of FIG. 2, the operation of the furnace soot blower 6 can be controlled at the same time when it is manually operated. That is, when the manual soot blower operation start signal 31 is input to the speed switching control device 26, the scraper conveyor high speed operation command device 27 continues to output the high speed operation signal 24 to the variable speed motor 23, When the soot blower operation end signal 32 is input to the speed switching control device 26, the output from the delay timer 33 output after a lapse of a predetermined time after the input of the soot blower operation end signal 32 is output from the scraper conveyor low speed operation command device 30. , And the low-speed operation signal 25 is continuously output to the variable speed motor 23. At this time, an OR circuit 34 for operating the scraper conveyor low-speed operation command device 30 when a signal is input from either one of the delay timers 29 and 33 is provided.

Next, the operation of the above embodiment will be described.

In the case where the furnace soot blower 6 is automatically operated, when the furnace soot blower 6 is in a state where the operation of the furnace soot blower 6 is stopped, when the furnace soot blower 6 is scheduled to be operated, the soot blower control device 8 executes the program command 7.
Soot blower operation signal 9 so that furnace soot blower 6 is operated based on a predetermined order.
And the operation of the furnace soot blower 6 is started.

Then, when the soot blower operation signal 9 is input to the scraper conveyor high-speed operation command device 27 of the speed switching control device 26, the scraper conveyor high-speed operation command device 27 immediately outputs the high-speed operation signal 24 to the switching circuit 35. Since the switching circuit 35 outputs the high-speed operation signal 24 to the variable speed motor 23 with priority, as shown in FIG. 3, the variable speed motor 23 is rotated at a high speed simultaneously with the start of the operation of the furnace soot blower 6. , The scraper conveyor 13 is operated at a high speed. At this time, the soot blower operation signal 9 is also input to the NOT circuit 28, but since the output of the NOT circuit 28 is 0 (zero), the scraper conveyor low-speed operation command device 30 does not operate.

Therefore, even if a large amount of ash C falls into the ash cooling water tank 12 due to the operation of the furnace soot blower 6, the ash C is not accumulated in the seal chute 10 by the scraper conveyor 13 operated at high speed. It will be discharged to the outside smoothly.

When the operation of all the furnace soot blowers 6 is completed, the soot blower operation signal 9 of the soot blower control device 8 disappears, but the scraper conveyor high speed operation command device 27 continues to output the high speed operation signal 24 to the variable speed motor 23. I have.

On the other hand, when the soot blower operation signal 9 disappears due to the end of the operation of the furnace soot blower 6, NOT
The circuit 28 outputs a signal of 1, and the output from the NOT circuit 28 is immediately input to the delay timer 29. The delay timer 29 performs the output after a predetermined time has elapsed from the input. When the delayed output is input to the scraper conveyor low-speed operation command device 30,
The scraper conveyor low-speed operation command device 30 outputs the low-speed operation signal 25 to the switching circuit 35, and the switching circuit 35 gives priority to the low-speed operation signal 25 and outputs the low-speed operation signal 25 to the variable speed motor 23, so that the scraper conveyor 13 is driven at a low speed. Will be done. That is, as shown in FIG. 3, the rotation speed of the variable speed motor 23, which was operating at a high speed during the operation of the furnace soot blower 6, is changed from the end of the operation of the furnace soot blower 6 to the time t (for example, Minutes), the speed can be switched to the low speed by the low speed operation signal 25.

Thus, it is possible to control the operation speed of the scraper conveyor 13 to be switched to a low speed after discharging a large amount of the ash C dropped into the ash cooling water tank 12 by the operation of the furnace soot blower 6. Thereafter, the scraper conveyor 13 is operated at a low speed until the furnace soot blower 6 is operated again.

In the case where the furnace soot blower 6 is manually operated and the furnace soot blower 6 is manually operated from a state in which the operation of the furnace soot blower 6 is stopped, the soot blower operation start signal 31 causes a speed switching control. Scraper conveyor high-speed operation command device 2 of device 26
7, the scraper conveyor high-speed operation command device 27 immediately outputs the high-speed operation signal 24 to the switching circuit 3.
5 and the switching circuit 35 outputs the high-speed operation signal 24 to the variable-speed motor 23 with priority, so that the variable-speed motor 23 is rotated at a high speed simultaneously with the start of the operation of the furnace soot blower 6 as shown in FIG. As a result, the scraper conveyor 13 is operated at a high speed.

When the operation of the furnace soot blower 6 is manually terminated from the state where the furnace soot blower 6 is operating, a soot blower operation end signal 32 is guided to the delay timer 33 of the speed switching control device 26, and the delay timer 33
Performs output after a predetermined time has elapsed from the input, and when the delayed output is input to the scraper conveyor low-speed operation command device 30, the scraper conveyor low-speed operation command device 30 outputs the low-speed operation signal 25. Switching circuit 35
The switching circuit 35 gives priority to the low speed operation signal 25 and outputs it to the variable speed motor 23, so that the scraper conveyor 13 is driven at a low speed. That is, as shown in FIG. 3, the rotation speed of the variable speed motor 23, which was operating at a high speed during the operation of the furnace soot blower 6, is changed from the end of the operation of the furnace soot blower 6 to the time t (for example, Minutes), and the low-speed operation signal 25
Can be switched to a lower speed.

Thus, it is possible to control the operation speed of the scraper conveyor 13 to be switched to a low speed after a large amount of the ash C dropped into the ash cooling water tank 12 by the operation of the furnace soot blower 6 is discharged to the outside. Thereafter, the scraper conveyor 13 is operated at a low speed until the furnace soot blower 6 is operated again.

[0035]

According to the present invention, when the operation of the furnace soot blower is started, the speed switching control device immediately outputs a high speed operation signal to the variable speed motor to operate the scraper conveyor at a high speed. Even if a large amount of ash falls into the ash cooling water tank due to the operation of the furnace soot blower, the ash is smoothly discharged to the outside without being accumulated in the seal chute by the scraper conveyor operated at high speed.

When the operation of all the furnace soot blowers is completed, the speed switching control device outputs a low speed operation signal to the variable speed motor after a lapse of the time set in the delay timer, and drives the scraper conveyor at a low speed. In order to start the operation, the ash dropped into the ash cooling water tank by the operation of the furnace soot blower is discharged to the outside, and then the operation of the scraper conveyor is switched to a low speed.

Accordingly, it is possible to prevent problems such as accumulation of ash in the seal chute, to enhance the safety of the seal chute and the scraper conveyor, to further reduce the wear of the scraper conveyor and to extend the life thereof, Excellent effects such as a reduction in power consumption can be achieved.

[Brief description of the drawings]

FIG. 1 is a cut-away side view showing an example of an ash processing apparatus to which the present invention has been applied.

FIG. 2 is a logic circuit diagram illustrating an example of a speed switching control device of FIG. 1;

FIG. 3 is a diagram showing the operation of the present invention.

FIG. 4 is a schematic side view showing an example of a coal-fired boiler.

FIG. 5 is a view taken in the direction of arrows VV in FIG. 4;

FIG. 6 is a view taken along the line VI-VI in FIG. 5;

[Explanation of symbols]

1 Coal-fired boiler 2 Furnace 6 Furnace soot blower 10 Seal chute 11 water 12 Ash cooling water tank 13 Scraper conveyor 14 Ash treatment equipment 23 Variable speed motor 24 High-speed operation signal 25 Low speed operation signal 26 Speed switching controller 29 Delay timer 33 Delay Timer C ash

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B65G 43/00-43/10 B65G 19/04 F23J 1/02

Claims (1)

(57) [Claims] 1. A seal chute is attached to a lower part of a furnace of a coal-fired boiler having a plurality of furnace soot blowers,
A coal-fired unit equipped with a scraper conveyor for inserting the lower end of the seal chute into a water-filled ash cooling water tank and scraping ash falling from the furnace through the seal chute into the ash cooling water tank outside the ash cooling water tank. Drive system for boiler ash treatment equipment
A control device, scraping speed of the scraper conveyor
A variable speed motor for driving the motor so that the degree can be changed;
A speed switching control device for controlling the operation speed of the motor.
Ri, the speed switching control device is slow to the variable speed motor wherein during operation of the furnace soot blowers outputs a high-speed operation signal to the variable speed motor scraper conveyor, after a predetermined time has elapsed the operation of the furnace sootblower is due to the delay timer when finished A drive control device for a coal-fired boiler ash treatment device, characterized by outputting an operation signal.