JPH09178157A - Controller for coal burning boiler fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize a steam temperature, pressure or the like by properly controlling the total amount of fuel supplied to a boiler during the change of the kind of coal (change of the rotating speed of a classifier). SOLUTION: A fuel controller to which a coal flow rate command 3 calculated based on a combustion amount command 2 and the total simulated amount of supplied coal 8 of a dust coal machine are input outputs a mill demand signal 9. In the fuel controller, time constant setting devices 17 to 20 for outputting a first order lag set for each kind of coal, switches 24A to 24C for selecting any one of the outputs of the time constant setting devices 17 to 20 depending on the kind of coal, and a simulated supplied coal amount computing means 15, to which the amount of fed coal of a coal feeder is input, for calculating the simulated supplied coal amount of the dust coal machine by using the outputs of the switches 24A to 24C are provided for each coal feeder. The simulated supplied coal amounts 6 and 7 calculated respectively for the coal feeders added together so that the total simulated supplied coal amount 8 of the dust coal machine is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel control device for a coal-fired boiler, and particularly, it accurately simulates the amount of pulverized coal machine simulated coal output when the rotational speed of a rotary classifier of a pulverized coal machine changes due to a change in coal type. And a fuel control device suitable for obtaining stable boiler characteristics.

[0002]

2. Description of the Related Art In fuel supply control of a coal-fired boiler, a fuel quantity command for a boiler is created according to a power generation quantity command of a power plant, and this fuel quantity command is supplied to a plurality of operating coal feeders. It is sent as a request signal (mill demand signal).

In the coal feeder, the speed of the coal feeder is adjusted according to the coal supply amount request signal, and the coal is supplied to the pulverized coal machine. The coal supplied from the coal feeder to the pulverized coal machine is crushed by the rollers in the pulverized coal machine. Downstream of the pulverized coal machine,
The rotary type that separates the coarse powder in the crushed coal and returns it to the crushing unit so that the fine powder crushed by the pulverized coal machine has a fine powder particle size suitable for combustion before being conveyed from the pulverized coal machine to the furnace A classifier is installed and has a mechanism to adjust the fine powder particle size by controlling the rotation speed. The pulverized coal that has passed through the classifier is transported into the boiler furnace by the primary air and burns in the furnace. As described above, the fuel of the coal-fired boiler is supplied to the furnace through the processes of coal feeding / crushing / classification / conveyance, so that the responsiveness of the fuel system has a large delay characteristic as compared with the oil / gas-fired boiler. doing.

FIG. 5 shows a conventional coal fuel control system for considering the delay characteristics of the coal fuel system of this coal-fired boiler.
The coal flow rate command (CFD) 3 is the combustion amount command (FRD) 2
Is a signal obtained by multiplying the mixed combustion rate setting (MXR) 1 by the multiplier 12 (oil flow rate command 16) from the FRD 2, and the mill demand signal 9 is the pulverized coal machine total simulated coal output 8 from CFD 3. It is a signal obtained by proportionally integrating the subtracted signal, and the mill demand signal 9 serves as a coal supply amount command to each coal feeder. Here, the total simulated coal output 8 of the pulverized coal machine has a first-order lag with respect to the measured values 4 and 5 of the coal supply to each pulverized coal machine, and the delay of the coal fuel system is determined by this first-order lag time constant. Is simulated.

However, this first-order lag is fixed regardless of the type of coal, and no consideration has been given to the fact that the coal output response characteristics with respect to changes in the rotational speed setting of the rotary classifier due to changes in the type of coal are greatly changed. The number of revolutions of this rotary classifier depends on the required fine powder particle size (generally, the higher the number of coals with a larger fuel ratio) from the combustibility of the coal and the necessity of suppressing vibration of the pulverized coal machine (the number of revolutions depends on the type of coal). If it is made higher, vibration easily occurs due to the friction angle of coal). Increasing the rotation speed of the rotary classifier increases the particle size of the pulverized coal discharged from the pulverized coal machine, that is, the proportion of coarse powder in the pulverized coal that is returned to the pulverization unit increases, which delays the coal production response. When the number of revolutions is decreased, the particle size of the pulverized coal discharged from the pulverized coal machine is reduced, that is, the ratio of the coarse powder in the pulverized coal returned to the pulverization unit is reduced, and thus the coal production response becomes faster.

As a general definition of coal type, a fuel ratio (ratio of fixed carbon and volatile matter) which is an index for evaluating combustibility obtained from components contained in coal and pulverizability of coal are evaluated. HGI is used as an index to determine the required fine powder particle size at the outlet of the pulverized coal machine, that is, the rotation speed of the rotary classifier from the fuel ratio, and the coal output characteristics vary depending on this rotation speed and the HGI characteristics of the coal type. It will be.

[0007]

The conventional control described above does not take into consideration that the coal output response characteristics greatly change with the setting change of the rotation classifier rotation speed due to the change of coal type. When the rotation speed setting was changed, there was a problem that the steam temperature and pressure of the boiler fluctuate when the load changes (mill demand fluctuation) for the following reasons.

The reason why the steam temperature and pressure of the boiler fluctuate is shown in FIG. Fig. 4 shows the same coal delay time constants (simulated output in Fig. 5) for A to C coals (rotational speed setting is A coal <B coal <C coal) with different rotation speed settings of the rotary classifier when the load increases. The simulated coal output amount characteristics when using the coal amount calculation means 15) are shown, the vertical axis shows the coal output amount and load, and the horizontal axis shows time. When the coal output delay time constant is used, the actual coal output is transiently larger than the simulated coal output signal (total pulverized coal machine simulated output of 8 in Fig. 5) when A coal is used, and C coal is also used. During use, the actual coal output is transiently less than the simulated coal output signal (total simulated coal output of pulverized coal machine in Fig. 3), so when changing the rotational speed of the rotary classifier due to coal type change, the boiler The steam temperature and pressure characteristics will fluctuate.

The object of the present invention is to accurately control the total amount of fuel supplied to the boiler by accurately simulating the coal output characteristics of the pulverized coal machine even when the type of coal is changed (the number of revolutions of the classifier is changed). However, another object of the present invention is to provide a control device that stabilizes boiler characteristics such as steam temperature and pressure.

[0010]

[Means for Solving the Problems] The above object is to change the first-order lag time constant used when calculating the simulated coal output of a pulverized coal machine for each coal type or by the rotation speed of a rotary classifier,
This is achieved by accurately simulating the coal output of the pulverized coal machine even when the coal type is changed.

As a first means for achieving the above object, the present invention provides a pulverized coal machine for pulverizing coal, a rotary classifier for classifying the particle size of the fine powder pulverized by the pulverized coal machine according to the number of revolutions, and the fine powder. A fuel control device for a coal-fired boiler, which is equipped with a coal feeder for supplying coal to a coal machine, controls the amount of coal supplied by the coal feeder by a mill demand signal, and supplies pulverized coal to a furnace to burn the coal. It is characterized in that means for calculating the simulated coal output of the pulverized coal machine fed back to the signal by the first-order lag time constant set for each coal type is provided.

As a second means for achieving the above object, instead of the means for calculating the simulated coal output of the pulverized coal machine from the first-order lag time constant set for each coal type, it corresponds to the rotation speed of the rotary classifier. A means for calculating the simulated coal output of the pulverized coal machine based on the first-order lag time constant set by the above may be provided.

As a third means for achieving the above-mentioned object, in place of the means for calculating the simulated coal output of the pulverized coal machine by the first-order lag time constant set for each coal type, the coal type and the rotation of the rotary classifier are replaced. A means for calculating the simulated coal output of the pulverized coal machine based on the first-order lag time constant set corresponding to the number may be provided.

As a fourth means for achieving the above object, the present invention comprises a pulverized coal machine for pulverizing coal, a rotary classifier for classifying the particle size of the fine powder pulverized by the pulverized coal machine according to the number of revolutions,
A coal feeder for supplying coal to the pulverized coal machine, a first computing means for generating and outputting a coal flow rate command based on a combustion amount command, and a simulated coal output of the pulverized coal machine fed back to the coal flow rate command. A second calculation means for generating a mill demand signal as an input, and the fuel control of a coal-fired boiler for controlling the coal feed amount of the coal feeder by the mill demand signal to supply pulverized coal to the furnace for combustion. In the equipment, feed back the simulated coal output of the pulverized coal machine as the primary delay time constant set for each coal type by inputting the coal type of the coal fed by the coal feeder and the coal output of the coal feeder. It is characterized in that a third calculating means for calculating by using is provided.

As a fifth means for achieving the above object, the present invention comprises a pulverized coal machine for pulverizing coal, a rotary classifier for classifying the particle size of the fine powder pulverized by the pulverized coal machine according to the number of revolutions,
A coal feeder for supplying coal to the pulverized coal machine, a first computing means for generating and outputting a coal flow rate command based on a combustion amount command, and a simulated coal output of the pulverized coal machine fed back to the coal flow rate command. A second calculation means for generating a mill demand signal as an input, and the fuel control of a coal-fired boiler for controlling the coal feed amount of the coal feeder by the mill demand signal to supply pulverized coal to the furnace for combustion. In the device, the simulated coal output of the pulverized coal machine to be fed back is input to the coal output of the coal feeder and the rotation speed of the rotary classifier connected to the pulverized coal machine supplied by the coal feeder to perform the rotary classification. It is characterized in that a fourth calculation means for calculating using a first-order lag time constant set according to the number of revolutions of the machine is provided.

As a sixth means for achieving the above object, the present invention comprises a pulverized coal machine for pulverizing coal, a rotary classifier for classifying the particle size of the fine powder pulverized by the pulverized coal machine according to the number of revolutions,
A coal feeder for supplying coal to the pulverized coal machine, a first computing means for generating and outputting a coal flow rate command based on a combustion amount command, and a simulated coal output of the pulverized coal machine fed back to the coal flow rate command. A second calculation means for generating a mill demand signal as an input, and controlling the amount of coal fed by the coal feeder by the mill demand signal to supply fuel to a furnace to supply pulverized coal for combustion; In the equipment, input the simulated coal output of the pulverized coal machine fed back, the coal output of the coal feeder, the type of coal, and the rotation speed of the rotary classifier connected to the pulverized coal machine fed by the coal feeder. As a second aspect, a fifth arithmetic means for calculating using the first-order lag time constant set according to the coal type and the rotation speed of the rotary classifier is provided.

As a seventh means for achieving the above object, the present invention pulverizes coal fed by a coal feeder by a pulverized coal machine and rotates the particle size of the fine powder pulverized by the pulverized coal machine by a rotary classifier. In a fuel control method for a coal-fired boiler in which pulverized coal classified according to number is supplied to a furnace and burned, the coal output of the coal feeder is controlled by a mill demand signal, and the fine powder is fed back to the mill demand signal. It is characterized in that the simulated coal output of the coal machine is calculated by the primary delay time constant set for each coal type.

As an eighth means for achieving the above object, the simulated coal output of the pulverized coal machine fed back to the mill demand signal is calculated by using the first-order lag time constant set in correspondence with the rotation speed of the rotary classifier. It may be calculated.

As a ninth means for achieving the above object, the simulated coal output of the pulverized coal machine fed back to the mill demand signal is set as a first-order lag time constant corresponding to the coal type and the rotation speed of the rotary classifier. You may make it calculate using.

As a tenth means for achieving the above object, the present invention crushes coal fed from a coal feeder with a pulverized coal machine and rotates the particle size of the fine powder pulverized with the pulverized coal machine with a rotary classifier. In a fuel control method of a coal-fired boiler that classifies by number, supplies classified pulverized coal to a furnace and burns it, generates and outputs a coal flow rate command based on a combustion amount command, and the fine powder fed back with the coal flow rate command. The simulated coal output of the coal machine is input, a mill demand signal is generated, the coal supply amount of the coal supply machine is controlled by the mill demand signal, and the simulated coal output of the pulverized coal machine is fed back by the coal supply machine. It is characterized in that the coal type of the coal to be coaled and the coal output of the coal feeder are used as inputs and the calculation is performed using the first-order lag time constant set for each coal type.

As an eleventh means for achieving the above object,
The simulated coal output of the pulverized coal machine to be fed back is input to the coal output of the coal feeder and the rotation speed of the rotary classifier connected to the pulverized coal machine supplied by the coal feeder, and the rotation of the rotary classifier is input. You may make it calculate using the primary delay time constant set according to the number.

As a twelfth means for achieving the above object,
The simulated coal output of the pulverized coal machine to be fed back is input as the coal output and coal type of the coal feeder and the rotation speed of the rotary classifier connected to the pulverized coal machine fed by the coal feeder. Alternatively, the calculation may be performed using the first-order lag time constant set according to the rotation speed of the rotation classifier.

In the case where the rotation classifier has a high rotation speed, that is, in the case of a high fuel ratio coal in which a high fine powder particle size is required to improve combustibility, the primary delay time constant for calculating the simulated coal output is increased, and When the rotational speed of the rotary classifier is low, that is, when the coal has a low fuel ratio, the primary delay time constant can be reduced to accurately simulate the coal output characteristics of the actual machine even when the coal type is changed. Since the appropriate adjustment of the total fuel flow rate is realized, the steam temperature and pressure characteristics due to the change of coal type do not significantly change.

[0024]

1 is a control block diagram according to a first embodiment of the present invention. The control device of the present embodiment includes a multiplier 12 that inputs a mixed fuel ratio setting (MXR) 1 and a fuel amount command (FRD) 2 and outputs an oil flow rate command 16, and an oil flow rate from the fuel amount command (FRD) 2. An adder 13A that subtracts the command 16 and outputs a coal flow rate command 3, and a coal flow rate command 3
From the pulverized coal machine total simulated coal output 8 and outputs the result, and the output of the adder 13B is proportionally integrated and output as a mill demand signal 9 to the coal feeder 10, 11, .... Proportional integrator 14, high fuel ratio coal, medium fuel ratio coal,
Time constant setters 17, 18, 19, 20 for outputting time constants corresponding to low fuel ratio coal and high humidity coal, respectively, and a switch for selecting and outputting one of the outputs of the time constant setters 17, 18. 24A, a switch 24B that selects and outputs one of the outputs of the time constant setter 19 and the switch 24A,
The output of either the time constant setter 20 or the switch 24B is selected and output as the primary delay time constant set value 21, and the coal feeding amount 4 of the coal feeder 10 is corrected by the primary delay time constant set value 21. Then, the simulated coal output amount calculating means 15 for outputting the simulated coal output amount 6 of the pulverized coal machine connected to the coal feeder 10 and the simulated coal output amount 6 and the pulverized coal machine connected to the coal feeder 11 are simulated. And an adder 13C that sums the coal production amount 7 and outputs it as a pulverized coal machine total simulated coal production amount 8.

The multiplier 12 and the adder 13A constitute a first calculating means, and the adder 13B and the proportional integrator 14 are the second.
Of the time constant setters 17, 18, 19,
20, the switches 24A, 24B, and 24C and the simulated coal output calculating means 15 constitute a third calculating means.

The switches 24A, 24B, and 24C are configured to receive a signal indicating a coal type. When a signal indicating a set coal type is input, the time constant of the corresponding coal type is selected. In other cases, the other signal is selected and output. The time constant setters 17, 18, 19, 20 are common to a plurality of coal feeders, and the switches 24A, 2
Only the downstream portion from 4B and 24C may be arranged for each coal feeding machine, or may be arranged for each coal feeding machine including the time constant setters 17, 18, 19, 20. In the figure, the time constant setters 17 ', 18', 19 ', 20', the switch 24
A ', 24B', 24C 'and simulated coal output calculating means 1
An example in which 5'is arranged corresponding to the coal feeder 11 is shown.
Coal types of medium fuel ratio coal, low fuel ratio coal, and high wet coal are set in the switches 24A, 24B, and 24C, respectively.

When a signal indicating a low fuel ratio coal is input to the switches 24A, 24B and 24C, a medium fuel ratio coal is set in the switch 24A, so the switch 24A sets the other signal, that is, a time constant setting. The output signal of the device 17 is selected and output. Next, since the low fuel ratio coal is set in the switch 24B, when the signal indicating the low fuel ratio coal is input, the switch 24B selects and outputs the output signal of the time constant setter 19. Next, since the high-humidity coal is set in the switch 24C, when the signal indicating the low fuel ratio coal is input, the switch 24C causes the other signal, that is, the switch 2 to operate.
4B output signal is selected and output. Therefore, the temporary delay time constant set value 2 output to the simulated coal output calculating means 15
1 is an output signal of the time constant setter 19 which outputs the time constant corresponding to the low fuel ratio coal.

In the control device having the above structure, the coal flow rate command (CFD) 3 is obtained by multiplying the fuel quantity command (FRD) 2 and the mixed fuel ratio setting (MXR) 1 by the multiplier 12 (oil flow rate command 16 ) Is subtracted from FRD2, and the mill demand signal 9 is a signal obtained by proportionally integrating a signal obtained by subtracting the total simulated coal output 8 from the pulverized coal machine from CFD3. The mill demand signal 9 supplies the coal to each coal feeder. It becomes a quantity command. here,
The total simulated coal output 8 of the pulverized coal machine has a first-order lag with respect to the coal supply amount (measured value) 4 to each pulverized coal machine, and this first-order lag time constant is changed depending on the coal type. That is, the simulated coal output calculating unit 15 shifts the coal supply amount 4 input continuously (or at predetermined sampling intervals) according to the first-order delay time constant, that is, the coal output of the pulverized coal machine, that is, This is output as a simulated coal output, but when this primary delay time constant is changed according to the type of coal to be supplied and the coal supply amount 4 at a certain point is input, that coal supply amount 4 is the simulated coal output amount. The amount of time lag until it is output as is changed.

In FIG. 1, as an example of coal type classification, the coal types are classified into high fuel ratio coal, medium fuel ratio coal, low fuel ratio coal, and high moisture content coal, and the time constant setter 17 for each coal type. , 18, 19, 2
0 is provided. When a certain coal feeding machine is set to feed the high fuel ratio coal, the time constant of the time constant setting unit 17 feeds the high fuel ratio coal, and the simulated coal output calculating means 15 of the coal feeding machine. Will be set to. Similarly, for other coal types, the time constant of the simulated coal output computing means 15 is changed,
The first-order lag time constant is set to match the rotation speed setting of the rotary classifier depending on the combustibility of coal.

In this embodiment, since the primary delay time constant for calculating the pulverized coal machine simulated coal output is set for each coal type,
It is possible to accurately simulate the coal output response characteristics from the pulverized coal machine, which varies for each coal type, and it is possible to realize appropriate adjustment of the total amount of fuel supplied to the boiler. As described above, it is possible to stabilize the boiler characteristics such as steam temperature and pressure even when the coal output response characteristics from the pulverized coal machine change due to the change of coal type, that is, the rotation speed of the rotary classifier.

FIG. 2 shows a second embodiment of the present invention. This embodiment is different from the first embodiment in that the time constant setter 1
7, 18, 19, 20 and switches 24A, 24B, 2
The point is that a function generator 23 that receives the classifier rotation speed 22 as an input and outputs the first-order delay time constant 21 is provided instead of 4C.
The function generator 23 and the simulated coal output calculating means 15 constitute the fourth calculating means, and the other configurations are the same as those in the first embodiment, so that the illustration and description thereof are omitted. The function generator 23 has a built-in function that outputs the first-order delay time constant 21 with the classifier rotation speed 22 as an input, and outputs the first-order delay time constant 21 according to the classifier rotation speed 22.

In this embodiment, instead of setting the primary delay time constant depending on the type of coal in FIG. 1, the primary delay time constant is changed by a primary delay time constant setting function having the rotation speed of the rotary classifier of the pulverized coal machine as a variable. It accurately simulates the difference in the coal output response characteristics depending on the number of revolutions of the classifier set for each type of coal, and realizes an appropriate adjustment of the total amount of fuel supplied to the boiler.

FIG. 3 shows a third embodiment of the present invention. This embodiment is a combination of the first and second embodiments,
A switch 24 for selecting any one of the time constant setters 17 to 19 for outputting a preset time constant according to the coal type and the time constant setters 17 to 19 according to the coal type.
A, 24B, 24C, a function generator 25 that generates and outputs a coefficient by inputting the number of revolutions 22 of the rotation classifier, and the output of the switch 24C and the output of the function generator 25 are multiplied and output as a first-order lag time constant 21. And a multiplier 26 for inputting the coal feed amount 4 of the coal feeder, and using the output signal of the multiplier 26, the simulated coal output amount calculation means 15 simulates the output of the pulverized coal machine connected to the coal feeder. It is configured to calculate the coal amount 6. Time constant setters 17 to 19 and switches 24A and 24
B, 24C, the function generator 25, the multiplier 26, and the simulated coal output computing means 15 constitute a fifth computing means. The other constituent elements are the same as those in the first embodiment, and the description thereof will be omitted.

In this embodiment, the time constant set according to the number of revolutions of the rotary classifier and the coal type and the coefficient set according to the number of revolutions of the rotary classifier for each coal type are used to obtain the primary delay time. Since the constant is calculated and the simulated coal output of the pulverized coal machine is calculated using this first-order lag time constant, more accurate simulated coal output characteristics can be obtained. The effect is to maintain a stable steam temperature characteristic even when the coal type is changed by adjusting the appropriate amount of fuel to

[0035]

According to the present invention, the coal discharge response characteristics of a pulverized coal machine depending on the type of coal can be set by setting the primary delay time constant depending on the type of coal or by setting the primary delay time constant depending on the rotational speed of the rotary classifier. Since it is possible to accurately simulate the simulated coal output characteristics and realize the appropriate adjustment of the total fuel amount to the boiler, the coal output response characteristics from the pulverized coal machine by changing the coal type, that is, the rotation classifier rotation speed. Even if
It is possible to stabilize the boiler characteristics such as steam temperature and pressure.

[Brief description of the drawings]

FIG. 1 is a control block diagram showing a first embodiment of the present invention.

FIG. 2 is a control block diagram showing a second embodiment of the present invention.

FIG. 3 is a control block diagram showing a third embodiment of the present invention.

FIG. 4 is a diagram showing a coal output response characteristic of a pulverized coal machine due to a difference in coal type, that is, a difference in rotation speed of a rotary classifier.

FIG. 5 is a control block diagram for creating a simulated coal output signal of a pulverized coal machine in the prior art.

[Explanation of symbols]

1 Mixed combustion rate setting 2 Combustion amount command 3 Coal flow rate command 4 A-Coal supply amount 5 B-Coal supply amount 6 A-Simulated coal output 7 B-Simulated coal output 8 Pulverized coal machine total simulated coal output 9 Mil demand 10 A-coal feeder 11 B-coal feeder 12 Multipliers 13A, 13B, 13C Adder 14 Proportional integrator 15 Simulated coal output amount calculation means 16 Oil flow rate command 17 Time constant setter (high fuel ratio coal) 18:00 Constant setter (medium fuel ratio coal) 19 Time constant setter (low fuel ratio coal) 20 Time constant setter (high humidity coal) 21 First-order lag time constant set value 22 A-Classifier rotation speed 23 Function generator 24A , 24
B, 24C switch 25 function generator 26 multiplier

Claims (12)

[Claims] 1. A pulverized coal machine for pulverizing coal, a rotary classifier for classifying the particle size of the fine powder pulverized by the pulverized coal machine according to the number of revolutions, and a coal feeder for feeding coal to the pulverized coal machine. In the fuel control device of the coal-fired boiler that controls the coal feed amount of the coal feeder by the mill demand signal and supplies the pulverized coal to the furnace for combustion, the simulated coal output of the pulverized coal machine fed back to the mill demand signal is set. A coal-fired boiler fuel control device comprising means for calculating a first-order lag time constant set for each coal type. 2. A first-order lag time constant set corresponding to the rotational speed of a rotary classifier, instead of the means for calculating the simulated coal output of the pulverized coal machine by the first-order lag time constant set for each coal type. The coal-fired boiler fuel control device according to claim 1, further comprising means for calculating a simulated coal output of the pulverized coal machine. 3. The simulated coal output of the pulverized coal machine fed back to the mill demand signal is replaced with a means for calculating the simulated coal output of the pulverized coal machine based on the first-order lag time constant set for each coal type. The coal-fired boiler fuel control device according to claim 1, further comprising means for calculating a first-order lag time constant set corresponding to the seed and the rotation speed of the rotary classifier. 4. A pulverized coal machine for pulverizing coal, a rotary classifier for classifying the particle size of the fine powder pulverized by the pulverized coal machine according to the number of revolutions, a coal feeder for supplying coal to the pulverized coal machine, and a combustion amount. A first calculation means for generating and outputting a coal flow rate command based on the command; and a second calculation means for generating a mill demand signal by inputting the simulated coal output of the pulverized coal machine fed back with the coal flow rate command. In the fuel control device of the coal-fired boiler for controlling and supplying the pulverized coal to the furnace by controlling the coal feeding amount of the coal feeding device by the mill demand signal, the simulated coal output of the pulverized coal feeding machine is fed back, It is characterized in that a third computing means is provided for calculating the coal type of the coal fed by the coal feeder and the coal output of the coal feeder using the first-order lag time constant set for each coal type. And a coal-fired boiler fuel control device. 5. Instead of the third calculation means, the simulated coal output of the pulverized coal machine fed back is connected to the coal output of the coal feeder and the pulverized coal machine supplied by the coal feeder. 5. The coal according to claim 4, further comprising: fourth arithmetic means for calculating the number of revolutions of the rotary classifier as an input and using a first-order lag time constant set according to the number of revolutions of the rotary classifier. Boiler fuel control system. 6. Instead of the third calculating means, the simulated coal output of the pulverized coal machine to be fed back is supplied to the coal output of the coal feeder, the type of coal, and the pulverized coal machine fed by the coal feeder. A fifth arithmetic means for calculating the number of revolutions of the connected rotary classifier as an input using a first-order lag time constant set according to the coal type and the number of revolutions of the rotary classifier is provided. Item 4. A coal-fired boiler fuel control device according to Item 4. 7. The coal fed by the coal feeder is pulverized by the pulverized coal machine, the particle size of the fine powder pulverized by the pulverized coal machine is classified by the number of rotations by the rotary classifier, and the pulverized coal is classified by the furnace. In a fuel control method for a coal-fired boiler that supplies and burns to a coal-fired boiler, the coal output of the coal feeder is controlled by a mill demand signal, and the simulated coal output of a pulverized coal machine that is fed back to the mill demand signal is set for each coal type. A coal-fired boiler fuel control method, characterized in that the fuel is controlled by a first-order lag time constant set in step 1. 8. The coal fed by a coal feeder is pulverized by a pulverized coal machine, the particle size of the fine powder pulverized by the pulverized coal machine is classified by the number of revolutions by a rotary classifier, and the pulverized coal is classified by a furnace. In a fuel control method for a coal-fired boiler that supplies and burns to a coal-fired boiler, the coal output of the coal feeder is controlled by a mill demand signal, and the simulated coal output of a pulverized coal machine that is fed back to the mill demand signal is a rotary classifier. The method for controlling fuel of a coal-fired boiler is characterized in that calculation is performed using a first-order lag time constant set corresponding to the number of revolutions. 9. Coal fed by a coal feeder is pulverized by a pulverized coal machine, and the particle size of the fine powder pulverized by the pulverized coal machine is classified by the number of revolutions by a rotary classifier, and the pulverized coal is classified in a furnace. In a fuel control method for a coal-fired boiler that supplies and burns to a coal-fired boiler, the coal output of the coal feeder is controlled by a mill demand signal, and the simulated coal output of a pulverized coal machine that is fed back to the mill demand signal is the coal type and A coal-fired boiler fuel control method, characterized in that calculation is performed using a first-order lag time constant set corresponding to the rotation speed of a rotary classifier. 10. Coal fed from a coal feeder is crushed by a pulverized coal machine, and the particle size of the fine powder pulverized by the pulverized coal machine is classified by the number of rotations by a rotary classifier, and the pulverized coal is classified in a furnace. In a fuel control method for a coal-fired boiler to supply and burn the coal flow rate command based on the combustion amount command,
A simulated demand of the pulverized coal machine is generated by inputting the simulated coal production amount of the pulverized coal machine fed back with the coal flow rate command, and the coal supply amount of the coal feeder is controlled by the mill demand signal to give a simulated output of the pulverized coal machine. It is characterized in that the amount of coal is calculated by using the first-order lag time constant set for each coal type with the coal type of the coal fed by the coal feeder and the coal output of the coal feeder as input. Method for controlling coal-fired boiler fuel. 11. Coal fed from a coal feeder is pulverized by a pulverized coal machine, and the particle size of the fine powder pulverized by the pulverized coal machine is classified by the number of rotations by a rotary classifier, and the pulverized coal is classified in a furnace. In a fuel control method for a coal-fired boiler to supply and burn the coal flow rate command based on the combustion amount command,
A simulated demand of the pulverized coal machine is generated by inputting the simulated coal production amount of the pulverized coal machine fed back with the coal flow rate command, and the coal supply amount of the coal feeder is controlled by the mill demand signal to give a simulated output of the pulverized coal machine. A primary quantity set according to the number of revolutions of the rotary classifier by inputting the output of the coal feeder and the number of revolutions of the rotary classifier connected to the pulverized coal machine fed by the coal feeder. A coal-fired boiler fuel control method characterized by being calculated using a delay time constant. 12. Coal fed from a coal feeder is pulverized by a pulverized coal machine, and the particle size of the fine powder pulverized by the pulverized coal machine is classified by the number of revolutions by a rotary classifier, and the pulverized coal is classified in a furnace. In a fuel control method for a coal-fired boiler to supply and burn the coal flow rate command based on the combustion amount command,
A simulated demand of the pulverized coal machine is generated by inputting the simulated coal production amount of the pulverized coal machine fed back with the coal flow rate command, and the coal supply amount of the coal feeder is controlled by the mill demand signal to give a simulated output of the pulverized coal machine. Input the coal output and the coal type of the coal feeder and the rotational speed of the rotary classifier connected to the pulverized coal machine supplied by the coal feeder into the coal type and the rotational speed of the rotary classifier. A coal-fired boiler fuel control method, characterized in that it is calculated using a first-order lag time constant set accordingly.