JP3763155B2 - Mill coal supply control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mill coal feed amount control device.
[0002]
[Prior art]
In coal-fired boilers, pulverized coal obtained by pulverizing coal with a pulverized coal machine (mill) is supplied to the boiler burner and burned, but the unit time of pulverized coal sent from the mill to the boiler burner When the power generation output command changes, the amount of coal output per hit needs to be controlled in accordance with the power generation output command. Therefore, in order to control the amount of pulverized coal discharged in response to the power generation output command, a mill coal supply amount control device that controls the amount of coal supplied to the mill is used.
[0003]
Thus, FIG. 6 shows an example of a mill equipped with a conventional coal supply control device.
[0004]
In the figure, reference numeral 1 denotes a mill, and a roller table 4 that can be rotationally driven by a driving device 3 is accommodated in a casing 2 of the mill 1, and the roller table 4 cooperates with the roller table 4. A plurality of pulverizing rollers 5 configured to pulverize the coal C1 are arranged so as to be rotated by frictional force with the roller table 4.
[0005]
In the upper center portion of the casing 2, a coal supply pipe 6 is disposed so as to pass through the ceiling 2 a of the casing 2 and be inserted into the casing 2 from above, and in the casing 2, the coal supply pipe 6 is provided. A reverse-headed cone-shaped hopper 7 that is concentrically surrounded is provided so as to be positioned immediately below the ceiling portion 2a. Between the hopper 7 and the casing 2 ceiling portion 2a, for example, a necessary amount in the circumferential direction is provided. A coarse powder separator 8 provided with a plurality of separation vanes 8a at a pitch is disposed.
[0006]
The ceiling portion 2a of the casing 2 has a reverse head cone portion and a lower head cone portion below the reverse head cone portion so as to be concentrically with the coal feed pipe 6 and between the coal feed pipe 6 and the coarse powder separator 8. A hopper 9 composed of a connected cylindrical portion is disposed so as to penetrate the ceiling portion 2a of the casing 2, and a pulverized coal supply pipe 10 for supplying pulverized coal C2 to the boiler burner is connected to the upper portion of the hopper 9. Has been.
[0007]
A primary air supply pipe 11 is connected to the lower part of the casing 2 so as to be positioned below the roller table 4, and the outer periphery of the roller table 4 and the casing are positioned above the connection part of the primary air supply pipe 11. 2 is provided with a plurality of primary air blowing nozzles 13 at a required interval in the circumferential direction, and the primary block introduced from the primary air supply pipe 11 into the casing 2. The air A can be blown to the upper side of the roller table 4 in the casing 2 through the primary air blowing nozzle 13.
[0008]
A coal feeder 14 is connected to the upper end of the coal supply pipe 6, and the coal C1 cut out from the bunker by the cutting device 15 is transferred onto the roller table 4 through the coal supply pipe 6 by the coal feeder 14. It can be thrown in.
[0009]
As the coal feeder 14, together with the coal feed amount detector 16 is connected, coal feed amount W _D per unit detected time by coal feed amount detector 16 may provide to the subtracter 17 as an electric signal has become, the subtracter 17, the difference [Delta] W in coal feed amount W _D from the command coal feed amount W _MWD and coal feed amount detector 16 corresponding to the power generation output command is determined by [Delta] W = W _MWD -W, The obtained difference ΔW is given as a control deviation to the proportional-plus-integral controller 18 and can be given as a coal feed amount correction command W _V to the drive device 19 of the coal feeder 14.
[0010]
Coal C <b> 1 cut out from the bunker by the cutting device 15 is input to the coal supply pipe 6 by the coal feeder 14 driven by the drive device 19, descends the coal supply pipe 6, and is driven by the drive device 3. Is supplied onto the roller table 4. Thus, the coal C1 supplied onto the roller table 4 is pulverized by the cooperation of the pulverizing roller 5 and the roller table 4 rotating by the frictional force with the roller table 4, and pulverized coal C2 is generated. .
[0011]
On the other hand, the primary air A supplied from the primary air supply pipe 11 into the casing 2 is blown out from the primary air blowing nozzle 13 above the roller table 4 of the casing 2 and rises in the casing 2 accompanied by pulverized coal C2. The pulverized coal is introduced into the pulverized powder separator 8, separated by the pulverized coal separator 8, discharged to the pulverized coal supply pipe 10 through the hopper 9, and supplied to the boiler burner together with the primary air A.
[0012]
Coarse pulverized coal C3 separated by the coarse pulverizer 8 slides down along the inner peripheral surface of the hopper 7, is supplied to the roller table 4 again, and is pulverized together with the coal C1 supplied from the coal supply pipe 6.
[0013]
During such operations, coal feed amount W _D coal C1 is charged in the casing 2 of the mill 1 by coal feeder 14 is detected by the coal feed amount detector 16, the detected coal feed amount W _D and the power generation output Directive coal feed amount W _MWD corresponding to the command is given to the subtracter 17, the subtracter 17, the difference ΔW command coal feed amount W _MWD and coal feed amount W _D is determined, the determined difference ΔW control command Is supplied to the proportional integral controller 18 and is proportionally integrated by the proportional integral controller 18 to obtain a coal feed amount correction command W _{V. The} obtained coal feed amount correction command W _V is used as a drive device 19 for the coal feeder 14. The rotational speed of the drive device 19 is adjusted to a predetermined rotational speed so that the difference ΔW output from the subtractor 17 becomes zero.
[0014]
On the other hand, during boiler operation, up from the power output command, for example, a low output to high output, command coal feed amount W _MWD in with coal feed amount W _D increases of from the W _D1 as shown in the solid line b in FIG. 7 If it becomes W _D2 increases by Kyusumiryou [Delta] W _UP, be immediately coal output W _E1 pulverized coal C2 sent to the pulverized coal supply pipe 10 of Figure 6 follows the Kyusumiryou W _D2 is Since there is a time delay of τ1 from when the coal supply amount W _D1 begins to increase until the coal output amount W _E1 begins to increase as shown by the dotted line b in FIG. After the coal amount W _D1 starts to increase, the coal supply amount becomes the coal supply amount W _D2 = W _D1 + ΔW _UP corresponding to the power generation output command, and then the coal output amount is substantially the coal output amount W corresponding to the power generation output command. _A large time constant τ2 is required before it is approximately balanced with _E2 = W _E1 + ΔW _UP .
[0015]
[Problems to be solved by the invention]
However, there is a time delay τ1, as described above, the time constant τ2 is large, it takes time to coal output W _E correspond to the generator output command, it takes time to shift to a stable operation of the boiler.
[0016]
In view of the above circumstances, if the coal weight W _D supply based on the increase in power generation output command is changed, the coal output W _E which is coal output from the mill and quickly and accurately coal feed amount W _D equilibrium It was made for the purpose of making it happen.
[0017]
[Progress of the present invention]
The coal output characteristics of pulverized coal obtained by pulverizing coal with a mill are greatly affected by the amount of coal circulating in the mill casing.
[0018]
As a result, the circulation amount of coal appears as a differential pressure (mill differential pressure) between the pressure below the roller table (primary air inlet side) in the mill casing and the pressure above the roller table. This also affects the flow rate of the primary air (mill air flow rate), the temperature (mill inlet air temperature), the amount of coal supplied to the mill, the amount of change in the amount of coal supply, and the rate of change.
[0019]
Therefore, if the relationship between these and the coal output is preliminarily measured during trial operation, etc., input to the neuro computer as data, and a neuro network is constructed with modules, etc., the coal output of pulverized coal can be increased by increasing the power generation output command. The time delay τ1 and time constant τ2 (see FIG. 7) when increasing can be predicted by learning.
[0020]
Furthermore, if the time delay τ1 and the time constant τ2 are predicted, the time delay τ1 is small and the time constant τ2 by increasing the amount of coal supply in advance of the power generation output command corresponding to the time delay τ1 and the time constant τ2. As a result, it is considered possible to perform optimal coal output control corresponding to the coal type of coal used.
[0021]
[Means for Solving the Problems]
In the present invention, a rotatable roller table 4 and a crushing roller 5 that collaborates with the roller table 4 to pulverize coal C1 to generate pulverized coal C2 are provided in the casing 2. In the mill 1 configured to supply the pulverized coal C2 generated by the air A introduced into the boiler burner through the pulverized coal supply pipe 10 communicating with the casing 2,
A pressure detector 20 for measuring a mill differential pressure ΔP between the lower side of the roller table 4 in the casing 2 and the upper side of the roller table 4;
A flow rate detector 21 for detecting a flow rate Q of the air A introduced into the casing 2;
A temperature detector 22 for detecting the temperature T of the air A introduced into the casing 2;
The coal feed amount detector 16 for measuring the coal feed amount W _D coal C1 to be introduced into the casing 2 by coal feeder 14 driven by the drive unit 19,
Mill differential pressure △ P from each detector 20,21,22,16, the flow rate Q of the air A, the temperature T, Kyusumiryou W _D and coal feed amount to be increased by increasing the power output command △ W _UP in parallel from the change rate R of the generator output command, from the start of increase in coal feed amount W _D by learning, time delay τ1 and up coal output W _E of pulverized coal C2 sent from the pulverized coal supply pipe 10 starts to increase A neurocomputer 24 for obtaining a time constant τ2 until the coal output W _E is substantially balanced with the increased coal supply W _D ;
Means 25 for determining the maximum preceding coal supply amount _{ΔW Dmax. Of the} coal C1 input into the casing 2 by the coal feeder 14 based on the time delay τ1 and the time constant τ2 from the neurocomputer 24;
A means 26 for determining the time tau _T of the time constant τ2 of the neuro-computer 24 from the start of rising coal feed amount W _D based on until turned up prior coal feed amount △ W _Dmax. Coal C1,
A proportional regulator 27 for obtaining a proportional preceding coal supply amount W _P from the maximum preceding coal supply amount ΔW _{Dmax. And the} time τ _T from the means 25, 26;
An integral controller 28 for obtaining an integrated preceding coal supply amount W _I from the maximum preceding coal supply amount _{ΔW Dmax. And} time τ _T from the means 25, 26;
An adder 29 for adding the proportional preceding coal supply amount W _P from the proportional controller 27 and the integral preceding coal supply amount W _I to obtain the preceding coal supply command W _S ;
A subtractor 17 for obtaining a difference △ W of coal feed amount W _D from the command coal feed amount W _MWD and coal feed amount detector 16,
A controller 18 for processing the difference ΔW from the subtractor 17 to obtain a coal feed amount correction command W _V ;
By adding the preceding coal feed rate command W _S from coal feed amount correction command W _V and the adder 29 from the controller 18 obtains the preceding coal feed amount correction command W _VA, feeding the leading coal feed amount correction instruction W _VA Adder 30 provided to drive device 19 of charcoal machine 14
Are provided.
[0022]
In the present invention, the time delay τ1 and the time constant τ2 are accurately obtained by learning in the neurocomputer 24.
[0023]
Therefore, to reduce the time delay τ1 to coal output W _E starts to increase, is substantially the same as the time constant when the coal feed amount W _D constant τ2 when coal output W _E is increased by a predetermined amount it becomes possible to perform in an optimum state in correspondence with the coal feed amount W _D of coal using the control of the coal output W _E because it is.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0025]
1-5 shows an example of embodiment of this invention, The mill itself used for embodiment of this invention is the structure substantially the same as what is shown in FIG. Accordingly, in the mill shown in FIG. 1, the same parts as those in FIG. 6 are denoted by the same reference numerals, and the description thereof will be omitted. Hereinafter, the mill coal supply control device will be mainly described.
[0026]
In FIG. 1, reference numeral 20 denotes a difference in pressure between the lower side of the roller table 4 in the casing 2 (on the inlet side of the primary air blowing nozzle 13) and the upper side of the roller table 4 (on the outlet side of the primary air blowing nozzle 13). A pressure detector 21 detects the pressure ΔP, a flow rate detector 21 detects the flow rate of the primary air A introduced from the primary air supply pipe 11 into the casing 2 as a mill air flow rate Q, and 22 a casing from the primary air supply pipe 11. temperature detector for detecting the temperature of the primary air a as the mill inlet air temperature T to be introduced into the 2, 23 detect the difference between the pressure of the pulverized coal supply pipe and hopper 9 10 as mill exit side differential pressure [Delta] P _C A coal feed amount W _D detected by the coal feed amount detector 16, a mill differential pressure ΔP detected by the pressure detector 20, a mill air flow rate Q detected by the flow rate detector 21, and a temperature detector 22. Detected by Mill inlet air temperature T was, the mill exit side differential pressure [Delta] P _C detected by the pressure detector 23 is adapted to be supplied to the neuro-computer 24 as the respective electrical signal.
[0027]
Further to the neuro-computer 24, when the power generation output command was up, and is able to set the Kyusumiryou W _D coal feed amount ΔW should increase to _UP and the change rate R of the generator output command.
[0028]
And Thus, the neuro-computer 24, based on the input various data, a time delay τ1 and coal feed amount W _D since Kyusumiryou W _D begins to increase until the coal output W _E starts to increase increased started fed-coal weight W _D from corresponds to the power generation output command was coal feed amount W _D, and the time constant until the subsequent coal output W _E approximately balanced with coal feed amount W _D corresponding to the power generation output command τ2 can be predicted.
[0029]
Reference numeral 25 denotes the maximum preceding coal supply among the preceding coal supply amounts that are input to the mill 1 in advance by the coal feeder 14 based on the time delay τ1 and the time constant τ2 predicted by the neurocomputer 24. the amount [Delta] W _Dmax. the finding function generator 26 based on the constant τ2 time predicted by neuro-computer 24, to the point where Kyusumiryou W _D turns on the maximum prior coal feed amount [Delta] W _Dmax. from starting to increase It is a function generator for obtaining the time τ _T of.
[0030]
27 is a proportional regulator for proportionally processing the maximum preceding coal supply amount ΔW _{Dmax. And} time τ _T from the function generators 25 and 26 to obtain the proportional preceding coal supply amount W _P , and 28 is from the function generators 25 and 26. An integral controller 29 that integrates the maximum preceding coal supply amount ΔW _{Dmax. And} time τ _T to obtain an integrated preceding coal supply amount W _I , 29 is the proportional preceding coal supply amount W _P from the proportional controller 27 and the integral controller 28. An adder for adding a preceding coal supply amount command W _S by adding the integral preceding coal supply amount W _I from the control unit 30, a coal supply amount correction command W _V from the proportional-plus-integral controller 18, and a preceding supply from the adder 29 by adding the coal amount command W _S, an adder which is adapted to output the preceding coal feed amount correction command W _VA.
[0031]
As shown in FIG. 2, the above-described neurocomputer 24 has a configuration of a neural network in which an input layer, an intermediate layer, and an output layer are hierarchically connected in order by synapses, and each layer has an input signal and a synapse from an external or previous layer. A neuron that performs a product-sum operation on the coupling coefficient, performs nonlinear conversion, and outputs it is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-210651.
[0032]
In the embodiment of the present invention, the input layer of the neurocomputer 24 comprises the coal supply amount W _D , the mill differential pressure ΔP, the mill air flow rate Q, the mill inlet air temperature T, and the coal supply amount ΔW _UP to be increased. The change rate R of the power generation output command, and the time layer τ1 and the time constant τ2 constitute the output layer.
[0033]
Moreover, the neuro-computer 24, the mill exit side differential pressure [Delta] P _C from the pressure detector 23 is input, it may determine the coal output W _E by Equation 1. In operation portion provided to the neural network constituent part It is like that.
[0034]
[Expression 1]
W _E = {(ΔP _C −ΔP _CO ) / ΔP _CO } × Q
[0035]
In [Equation 1], ΔP _CO is a pressure loss in the absence of coal between the connection portion of the pressure detector 23 to the hopper 9 and the connection portion to the pulverized coal supply pipe 10, and [Equation 2]. Is obtained by calculation in advance.
[0036]
[Expression 2]
ΔP _CO = K · (v ² / 2g)
[0037]
Here, K is a shape factor, and v is a theoretical velocity of the primary air A flowing in the pulverized coal supply pipe 10.
[0038]
As shown in FIG. 3, the function generator 25 receives a function indicating the relationship between the time delay τ1 and the maximum preceding coal supply amount ΔW _{Dmax. When} the time constant τ2 changes. are input function showing the relationship between time tau _T from starting to increase constant τ2 and coal feed amount W _D is to the maximum prior coal feed amount [Delta] W _Dmax. when as shown in.
[0039]
In FIG. 3, a, b, c, d, and e are time constants.
[0040]
Next, the operation in the embodiment of the present invention will be described.
[0041]
For example, during a trial operation, the initial coal supply amount W _D , mill differential pressure ΔP, mill air flow rate Q, mill inlet, while changing the coal type set in the neurocomputer 24, the amount of coal supply ΔW _UP to be increased, and the change speed R are variously changed. air temperature T, measured mill exit side differential pressure [Delta] P _C, these time delays τ1 and inputs to the neural computer 24, the time constant τ2 is measured as the data, which also keep the input to the neural computer 24. For example, as an example of input data, coal supply amount W _D = 50 t / h, coal supply amount to be increased ΔW _UP = 5 t / h, power generation output command change rate R = 10 MW / min. , Mill differential pressure ΔP = 450 mmAq, mill air flow rate Q = 100 t / h, mill inlet air temperature T = 250 ° C., time delay τ1 = 60 sec. , Time constant τ2 = 120 sec. There is. If a large number of these data are input, the accuracy is improved accordingly.
[0042]
When the power generation output command is not changed and the operation is performed at a constant value, the time delay τ1 and the time constant τ2 are not output from the neurocomputer 24. Therefore, the function generators 25 and 26, the proportional regulator 27, the integration The output from the adjuster 28 becomes zero, and the output from the adder 29 also becomes zero. For this reason, in the adder 30, the signal from the adder 29 is not added, and as in the case of FIG. 6, the coal feed amount correction command W _V output from the proportional-plus-integral regulator 18 is directly applied to the coal feeder. given to the driving device 19 of the 14, by the driving device 19 is controlled, coal feed amount W _D coal C1 to be introduced into the casing 2 of the mill 1 by coal feeder 14 to a command coal feed amount W _MWD It is controlled to become.
[0043]
By generating output command is up, if than originally coal feed amount W _D increases the coal feed amount, first the APC (Automatic Plant Control) or the like, should increase coal feed amount [Delta] W _UP, the power generation output command The change rate R is input to the neurocomputer 24.
[0044]
Further, the coal supply amount W _D from the coal supply amount detector 16, the mill differential pressure ΔP from the pressure detector 20, the mill air flow rate Q from the flow rate detector 21, the mill inlet air temperature T from the temperature detector 22, The mill outlet differential pressure ΔP _C from the pressure detector 23 is input to the neurocomputer 24 as data.
[0045]
Thus, in the neurocomputer 24, the product-sum operation and the sigmoid function conversion process are performed for each intermediate layer neuron based on the data of the input layer, and the time delay τ1 and the time constant τ2 which are outputs from the output layer are obtained. The time delay τ1 is given to the function generators 25 and 26, and the time constant τ2 is given to the function generator 26.
[0046]
Thus, in the function generator 25, the maximum preceding coal supply amount ΔW _Dmax. Is obtained from the time delay τ1 and the time constant τ2, and the obtained maximum preceding coal supply amount ΔW _Dmax. Is provided to the container 28.
[0047]
The function generator 26 obtains a time τ _T from when the time constant τ 2 and the coal supply amount W _D start to increase until the coal C 1 having the maximum preceding coal supply amount ΔW _{Dmax. T} is provided to the proportional regulator 27 and the integral regulator 28.
[0048]
In the proportional regulator 27, the maximum preceding coal supply amount ΔW _Dmax. And the time τ _T are proportionally adjusted to obtain the proportional preceding coal supply amount W _P , and the obtained proportional preceding coal supply amount W _P is given to the adder 29. The integral regulator 28 integrates and adjusts the maximum preceding coal supply amount ΔW _Dmax. And the time τ _T to obtain the integrated preceding coal supply amount W _{I. The} obtained integral preceding coal supply amount W _I is added to the adder 29. given, in the adder 29, a proportional preceding coal feed amount W _P and the integral preceding coal feed amount W _I is preceded coal feed amount is added command W _S is obtained, the obtained preceding coal feed rate command W _S is It is given to the adder 30.
[0049]
On the other hand, the command coal supply amount W _MWD that increases with the increase in the power generation output command is given to the subtractor 17, and the subtractor 17 receives the command coal supply amount W _MWD and the coal supply amount W _D from the coal supply amount detector 16. Is obtained, and the obtained difference ΔW is proportionally integrated by the proportional-plus-integral controller 18, and the obtained coal feed amount correction command W _V is given to the adder 30.
[0050]
In the adder 30, a proportional integral controller 18 coal feed amount correction of the command W _V and the preceding coal feed rate command W _S is added prior coal feed amount correction command W _VA is obtained, the obtained preceding coal feed amount since the correction instruction W _VA is applied to the driving device 19 of the coal feeder 14, the drive unit 19, the original coal feed amount correction command W prior coal feed rate command than _V W _S amount corresponding large amount of coal C1, prior The coal is fed into the casing 2 of the mill 1.
[0051]
Thus, coal Kyusumiryou W _D even when up transient of which only up coal feed amount [Delta] W _UP, the constant τ2 is also reduced when without significant time delays τ1 in coal output W _E occurs, use It is possible to perform optimal coal output control in response to this.
[0052]
During the control of these coal output, coal output W _E is determined by [Equation 2] described above, it is displayed on the display unit (not shown).
[0053]
The state of changes in the coal supply amount and the coal output amount when performing such coal output control will be described with reference to the graph of FIG. That is, by the power generation output command is up, when increased to Kyusumiryou W _D the coal feed amount W corresponding to the new power output command from the beginning of the coal feed amount _{W D1 D2 = W D1 + ΔW} UP , the function The maximum leading coal supply amount ΔW _Dmax. Obtained by the generator 25 is gradually increased substantially linearly (see solid line C) so that it can be obtained after time τ _T after the start of the increase in the coal supply amount W _{D1 .} After the time τ _T when the coal supply amount ΔW _Dmax. Is obtained, the amount is gradually decreased substantially linearly so that the preceding coal supply amount becomes zero when the coal supply amount becomes W _D2 = W _D1 + ΔW _UP . As a result, as indicated by a dotted line D in FIG. 5, coal output W _E is the time delay is small and gradually increases in a state of following the change rate R of substantially power output command, coal feed amount W _D2 = W _As soon as _D1 + ΔW _UP is reached, the coal output W _E2 = W _E1 + ΔW _UP substantially coincides with the coal supply amount W _D2 . In this case, the circulation amount of coal in the casing 2 of the mill 1 increases (the circulation amount of coal is represented by a triangle in FIG. 5).
[0054]
As described above, in increasing the coal output W _E for increased power generation output command is will perform control for increasing in advance the Kyusumiryou W _D, is previously input in this Based on data such as mill differential pressure ΔP, mill air flow rate Q, mill inlet air temperature T, coal feed amount W _D before power generation output command rise, coal feed amount ΔW _UP to be increased, power generation command change rate R In addition, the time delay τ1 and the time constant τ2 can be accurately obtained by learning in the neurocomputer 24.
[0055]
Therefore, it is possible to coal output W _E is eliminated the time delay τ1 to starts to increase, is substantially the same as the number of hours when the coal feed amount W _D constant τ2 when coal output W _E increases Therefore, it is possible to perform in an optimum state in correspondence with the coal feed amount W _D of coal using the control of the coal output W _E.
[0056]
Of course, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.
[0057]
【The invention's effect】
According to the mill coal feed amount control device of the present invention, precisely by control of the coal output W _E when coal feed amount W _D by increased power generation output command is increased corresponding to the change of the coal feed amount W _D Therefore, various excellent effects such as being able to promptly shift to stable operation of the boiler can be obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an example of an embodiment of a mill coal feed amount control device of the present invention.
FIG. 2 is a diagram showing an outline of a neural network incorporated in the neurocomputer of FIG.
FIG. 3 is a graph of a function input to one of the two function generators shown in FIG. 1;
FIG. 4 is a graph of a function input to the other function generator of the two function generators shown in FIG. 1;
FIG. 5 is a graph showing changes over time in the amount of coal supply and the amount of coal output when the amount of coal supply is increased in advance according to the embodiment of the present invention.
FIG. 6 is a block diagram showing an example of a conventional mill coal feed amount control device.
FIG. 7 is a graph showing changes over time in the amount of coal supply and the amount of coal output when the amount of coal supply is increased in the example of FIG. 6;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Mil 2 Casing 4 Roller table 5 Grinding roller 10 Pulverized coal supply pipe 14 Coal feeder 16 Coal feed amount detector 17 Subtractor 18 Proportional integral regulator (regulator)
19 Drive device 20 Pressure detector 21 Flow rate detector 22 Temperature detector 24 Neurocomputer 25 Function generator (means)
26 Function generator (means)
27 proportional controller 28 integral controller 29 adder 30 adder C1 coal C2 pulverized coal A primary air τ1 time delay τ2 time constant W _MWD command coal supply amount W _D coal supply amount W _E coal output amount ΔW difference ΔP mill Differential pressure Q Mill air flow (air flow)
T Mill inlet air temperature (air temperature)
△ W _UP Coal feed amount R to be increased R Change speed △ W _Dmax. Maximum preceding coal feed amount τ _T Time W _P Proportional preceding coal feed amount W _I Integral preceding coal feed amount W _S Advance coal feed amount command W _V Coal feed amount Correction command W _VA advance coal supply correction command

Claims (1)

A casing (2) is provided with a rotatable roller table (4) and a crushing roller (5) for crushing coal (C1) and generating pulverized coal (C2) in cooperation with the roller table (4), The pulverized coal (C2) generated by the air (A) introduced into the casing (2) from below the roller table (4) is supplied to the boiler burner through the pulverized coal supply pipe (10) communicating with the casing (2). In the mill (1)
A pressure detector (20) for measuring a mill differential pressure (ΔP) between the lower side of the roller table (4) in the casing (2) and the upper side of the roller table (4);
A flow rate detector (21) for detecting a flow rate (Q) of air (A) introduced into the casing (2);
A temperature detector (22) for detecting the temperature (T) of the air (A) introduced into the casing (2);
A coal feed detector (16) for measuring the coal feed (W _D ) of the coal (C1) charged into the casing (2) by the coal feeder (14) driven by the drive device (19);
Mill differential pressure (ΔP), air (A) flow rate (Q), temperature (T), coal supply amount (W _D ) and power generation output from each detector (20) (21) (22) (16) The pulverized coal supply pipe (10) after the amount of coal supply (W _D ) starts to increase due to learning from the change rate (R) of the power generation output command as well as the amount of coal supply (ΔW _UP ) to be increased by the increase in the command Is approximately balanced with the time delay (τ1) until the coal output (W _E ) of the pulverized coal (C2) delivered from the engine begins to increase and the coal supply (W _D ) with the increased coal output (W _E ). A neurocomputer (24) for calculating the time constant (τ2) up to
Based on the time delay (τ1) and time constant (τ2) from the neurocomputer (24), the maximum preceding coal supply amount of the coal (C1) charged into the casing (2) by the coal feeder (14) ( _{ΔW Dmax.} ) (25)
Time from the start of the increase in coal supply (W _D ) based on the time constant (τ2) from the neurocomputer (24) until the introduction of coal (C1) with the maximum preceding coal supply ( _{ΔW Dmax.} ) Means (26) for determining (τ _T );
A proportional regulator (27) for determining a proportional preceding coal supply amount (W _P ) from the maximum preceding coal supply amount (ΔW _Dmax. ) And time (τ _T ) from the means (25) (26);
An integral controller (28) for determining an integrated preceding coal supply amount (W _I ) from the maximum preceding coal supply amount ( _{ΔW Dmax.} ) And time (τ _T ) from the means (25) (26);
An adder (29) for adding the proportional preceding coal supply amount (W _P ) and the integral preceding coal supply amount (W _I ) from the proportional regulator (27) to obtain the preceding coal supply amount command (W _S );
A subtractor (17) for obtaining a difference ( _ΔW ) between the command coal supply amount (W _MWD ) and the coal supply amount (W _D ) from the coal supply amount detector (16);
A controller (18) for processing a difference (ΔW) from the subtractor (17) to obtain a coal feed amount correction command (W _V );
Add the coal supply amount correction command (W _V ) from the controller (18) and the preceding coal supply amount command (W _S ) from the adder (29) to obtain the preceding coal supply amount correction command (W _VA ), Adder (30) for giving a preceding coal supply amount correction command (W _VA ) to the drive unit (19) of the coal feeder (14)
A mill coal feed amount control device characterized by comprising:

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