JPH11333319A - Apparatus for automatic estimation of coal pulverizability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily estimate pulverizability by combining process data, such as coal feed rate, the current of a mill motor and the number of revolutions of a rotary classifier, and a preset constant, executing plural steps of computation, adding a response delay thereto and determining the output of the resulted primary delay element as the estimated value of the coal pulverizability. SOLUTION: This apparatus which executes the pulverization of the coal by pressing the plural rolls installed to the outer peripheral part of a turntable to a table selects the higher of the number-of-revolution signal 22 of the rotary classifier and the output signal of a constant generator 65 by a high signal selector 64 and sends this signal to a divider 66. A mill motor current signal 21 is divided by the output signal of the high signal selector 64. This divided value is sent to a subtractor 68 which determines a deviation from a reference value by the standard card from a function generator 67 to be inputted with a mill coal feed rate signal 03. This deviation is thereafter multiplied by the constant including the coefft. and thereafter, the multiplication result and the constant are added and the response delay is added to this arithmetic value. The output of the resulted primary delay element is determined as the estimated value of the coal pulverizability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for automatically estimating the pulverizability of coal in a coal pulverizer. Automatic estimating apparatus.

[0002]

2. Description of the Related Art In a coal pulverizer, coal having a low degree of coalification is easily pulverized, but is not easily pulverized. As coalification proceeds, it becomes easier to grind, and as it proceeds further, it becomes more difficult to grind again. In general, those having a large amount of water and ash are hard to be crushed. Such a method for testing the pulverizability of coal, which is an index representing the hardness of coal properties, includes a ball mill method and a hard glove method.
It is difficult to measure online during boiler operation, and only the device shown in FIG. 7 exists.

FIG. 7 shows an optimum operation amount u from the operation amount controller 102 and a parameter θ from the coal grindability estimator 105.
, The burner inlet pulverized coal flow rate estimated value χ obtained by the mill dynamic characteristic model 103 is input to a subtractor 101 to obtain a deviation from a target value.
To determine the optimal operation amount u, and based on the optimal operation amount u, control the coal supply amount, the classifier rotation speed, and the pressing force.

[0004] A mill differential pressure prediction value y 'together with a pulverized coal flow rate estimation value よ り as an output value from the mill dynamic characteristic model 103.
And a difference signal between the mill differential pressure prediction value y ′ and the mill table differential pressure measurement value y is calculated by the subtractor 104 using the coal pulverizability estimator 10.
5 to determine the parameter θ.

[0005]

However, even in such a conventional technique, a considerable amount of labor is required for the mill dynamic characteristic model to accurately estimate coal having different properties using the differential pressure of the mill having large fluctuations. I do. For this reason, in a coal-rich coal-fired boiler, finely pulverized coal (pulverized coal) is supplied to the burner as fuel from a plurality of coal pulverizers. Since the change in the actual mill capacity due to the pulverizability (HGI) cannot be grasped, the control of the number of coal pulverizers requires a considerable margin of switching.

[0006] Accordingly, even in a coal-fired coal-fired boiler,
If the properties of coal, especially the pulverizability of coal, can be measured online, significant controllability can be expected. More specifically, if the pulverizability of coal can be estimated online, the following advantages are obtained. 1) The maximum capacity of the coal crusher can be easily grasped, and the number of coal crushers can be accurately controlled. 2) The amount of pulverized coal supplied from the coal crusher to the burner can be predicted by using an appropriate model. 3) If the above advantages are utilized in the control device, controllability and reliability can be improved.

In view of the above demand, the present invention provides a coal pulverizing apparatus attached to a coal-fired boiler that uses a plurality of types of coal having different properties as a fuel. It is an object of the present invention to provide a crushability automatic estimation device.

[0008]

Means for Solving the Problems The applicant of the present invention initially focused on the fact that the grindability (HGI) of coal is correlated with the current of the mill motor, the number of revolutions of a rotary classifier (MRS), and the amount of coal supplied. In addition, it was also found that the correlation between the hydraulic pressure of the mill press and the roll lift was considerably large in the grindability (HGI) of coal. The present invention estimates the pulverizability of coal by selectively and variously combining various process data of a hydraulic roll lift of a current rotation classifier (MRS) rotational speed mill pressurizing device of a coal feed mill motor based on such knowledge. The gist is that.

That is, according to the present invention, in a plurality of types of coal pulverizers having different properties, a coal feed amount, a mill motor current, and a rotary classifier (M) obtained from the pulverizer are provided.
RS), two or more process data selected from among the process data of each of the rotational speed, the hydraulic pressure of the mill pressurizing device, and the roll lift, and a preset constant are combined to perform a multi-stage operation. The output of the first-order lag element obtained by adding the response delay to the output signal is used as an estimated value of coal pulverizability.

The invention according to claim 2 corresponds to the first to third embodiments to be described later. In a plurality of types of coal pulverizers having different properties, the amount of coal supplied and the mill motor obtained by the pulverizer are obtained. One or a plurality of process data selected from among the process data of the current, the number of revolutions of the rotation classifier (MRS), the oil pressure of the mill pressurizing device, and the roll lift are combined with data obtained by direct or predetermined arithmetic processing. Subtraction means for calculating a deviation between the respective data and a reference value output from a function generator having a mill coal feed rate as an input;
Multiplying means for multiplying the deviation by a constant including a coefficient, adding means for adding a constant to an output signal of the multiplying means,
A primary delay element that adds a response delay to an output signal of the next operation means, and an output of the primary delay element is used as an estimated value of coal pulverizability.

This invention relates to a coal pulverizing apparatus attached to a coal-fired boiler using a plurality of types of coal having different properties as fuel, for example, as shown in FIG. Specified. That is, the invention according to claim 3 is based on the fact that the coal crushability (HGI) is correlated with the current of the mill motor, the number of revolutions of the rotary classifier (MRS), and the amount of coal supplied. A dividing means 66 for obtaining a ratio between the mill motor current 21 of the apparatus and the number of revolutions 22 of the rotary classifier, a reference obtained from a function generator 67 having the ratio obtained by the dividing means and the mill coal feed 03 as input. Subtraction means 68 for determining a deviation from the value;
Multiplied by a coefficient, further multiplied by a coefficient, multiplied by a coefficient and added by a constant, and a secondary operation means 69-74 comprising a multiplier and an adder; and outputs of the secondary operation means 69-74. A first-order lag element 77 for adding a response delay to the signal, and an output of the first-order lag element 77 is used as an estimated value of the coal pulverizability.

The invention described in claim 4 is based on the fact that the pulverizability (HGI) of coal has a correlation between the hydraulic pressure 01 of the mill pressurizing device and the roll lift 02. In a coal crusher attached to a coal-fired boiler using coal of a certain type as a fuel, as shown in FIG.
Multiplying means 04 for multiplying 1 by the roll lift 02; subtracting means 06 for calculating the deviation between the value obtained by the multiplying means 04 and the reference value output from the function generator 05 which receives the mill coal supply 03 as input. And quadratic arithmetic means 07-14 for adding a constant obtained by squaring the deviation and further multiplying the coefficient, a coefficient obtained by multiplying the deviation by a coefficient, and a constant.
And a first-order lag element 15 for adding a response delay to the output signals of the second-order calculation means 07 to 14, and the output of the first-order lag element 15 is used as an estimated value of coal pulverizability.

According to a fifth aspect of the present invention, in the apparatus for automatically estimating the pulverizability of coal according to the second aspect, the mill is selected from among a hydraulic pressure of a mill pressing device, a roll lift, a mill motor current, and a rotational speed of a rotary classifier. A plurality of subtraction means for obtaining a deviation between the obtained two or more process data, a reference value output from a function generator having the process data and a mill coal supply as inputs, and a plurality of subtraction means, respectively. Multiplying the deviation by a constant, multiplying means of a number corresponding to the subtracting means,
Adding means for adding signals of the plurality of multiplying means,
A primary delay element is added to the output signal of the adding means in consideration of a response delay, and the output of the primary delay element is used as an estimated value of coal pulverizability.

That is, according to the present invention, as illustrated in FIG. 3, a reference value output from a function generator 23 having a mill pressurizing device oil pressure 01 of a coal pulverizer and a mill feed amount 03 as inputs. 24, a multiplying means 32 for multiplying the deviation by a constant, and a deviation from a reference value output from a function generator 25 having a roll lift 02 and a mill coal feed 03 as inputs. A subtraction means 26, a multiplication means 34 for multiplying the deviation by a constant, a subtraction means 28 for obtaining a deviation from a reference value output from a function generator 27 having the mill motor current 21 and the mill coal supply 03 as inputs, A multiplication means 36 for multiplying the deviation by a constant; a subtraction means 30 for obtaining a deviation between a rotation classifier rotation speed 22 and a reference value output from a function generator 29 having the mill coal supply 03 as an input; Multiplies by a constant And calculation means 38, multiplying means 32 and 34
Adding means 39 for adding,, and 36, and a first-order lag element 40 for adding a response delay to an output signal of the adding means 39.
With this configuration, the output of the first-order lag element can be used as an estimated value of coal pulverizability.

According to a sixth aspect of the present invention, in the automatic coal crushability estimating apparatus of the first aspect, the arithmetic means is simplified, and a hydraulic pressure of a mill pressurizing device, a roll lift, and a mill motor current of the crushing device are provided. A plurality of multiplication means for multiplying the process data of each of the rotation classifier rotation speed and the mill coal feed amount by a constant; an addition means for adding a signal of each of the plurality of multiplication means; and a response to an output signal of the addition means. A primary delay element that takes into account the delay is provided, and the output of the primary delay element is used as an estimated value of coal crushability.

That is, according to the present invention, as illustrated in FIG. 4, a multiplying means 52 for multiplying a mill pressurizing apparatus hydraulic pressure 01 of a coal pulverizing apparatus by a constant, and a multiplying means 54 for multiplying a roll lift 02 by a constant. Multiplication means 56 for multiplying the mill motor current 21 by a constant, multiplication means 58 for multiplying the rotation classifier rotation speed 22 by a constant, multiplication means 60 for multiplying the mill coal supply 03 by a constant, and multiplication means 52 By adding an adding means 61 for adding 54, 56, 58, and 60, and a first-order lag element 62 for adding a response delay to the output signal of the adding means 61, the output of the first-order lag element is obtained. Can be used as an estimate of the grindability of the coal.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. However, unless otherwise specified, the types, relative arrangements, numbers, and connection states of the components described in this embodiment are not intended to limit the scope of the present invention, but are merely illustrative examples. It's just

FIG. 5 is a block diagram of a coal crusher (mill) to which the present invention is applied. The configuration of the present apparatus will be described along with its operation. Coal (raw coal) is supplied from a top of a coal pulverizer 100 through a coal feed pipe 1 inserted at the center, and a rotary table provided at the bottom of the coal pulverizer. 2 and is carried to the outer periphery by the centrifugal force generated by the rotation of the rotary table 2.

The plurality of rolls 3 provided on the outer periphery of the rotary table 2 are moved by the hydraulic pressure 01 of
, And the coal is pulverized between the roll 3 and the table 2. The finely pulverized coal is blown up by primary air (hot air) 5. The primary air 5 has a role of transporting and drying the coal. The pulverized coal that has been blown up is relatively
The particles fall down and are re-ground, and only relatively fine particles are guided to the rotary classifier 6 provided at the top of the coal mill 100. Here, coarser and finer particles are re-classified, and only relatively fine particles 7 pass through a classifier 6 and are supplied to a burner (not shown).

In the configuration of such a coal pulverizing apparatus, the pulverizability of the coal is, as shown in FIG. 6, a current of a mill motor for rotating the rotary table 2 through a speed reducer 21.
As a result of the analysis in FIG. 6, it has become clear that there is a correlation between 1 and the rotational speed 22 of the rotation classifier (MRS) 6.

FIG. 6A shows the relationship between the current 21 of the mill motor and the amount of coal supply 03. As is apparent from this figure, the Obbet coal having a coal grindability (HGI) of 47 and a relatively hard coal type is shown. Shows a relatively larger value than Newlands coal (HGI = 64), which is a soft coal type, for the same coal supply amount 03. Bloomfield coal, whose coal grindability is intermediate (HGI = 53), has an intermediate value.

FIG. 6B shows the relationship between the number of revolutions 22 of the rotary classifier (MRS) and the amount of supplied coal 03. Rotating classifier (MR
S) The number of revolutions 22 is the operating end of the control system, and is determined by other indices.
In the case of Obet charcoal, which represents a relatively hard coal type of 7, it is a small value.
Newlands charcoal, a soft coal type (HGI = 64)
It can be seen that the value is large.

In the present embodiment, the current 21
The present invention relates to an apparatus for estimating the pulverizability of coal supplied online from process data focusing on the relationship between the amount of coal supplied and the number of rotations of a rotary classifier (MRS) 22. FIG.
Is an apparatus for estimating the pulverizability of coal according to the first embodiment of the present invention, and outputs the pulverizability of coal by inputting the flow rate of coal supplied to the coal pulverizer, the mill motor current 21, and the MRS rotation speed 22. It is configured to be.

That is, the present apparatus inputs the mill motor current 21, the rotation classifier (MRS) rotation speed 22, and the mill coal feed amount 03, which are process data, and outputs the estimated coal pulverizability 78 online.

Hereinafter, the present apparatus will be described in detail with reference to FIG. The signal of the rotation classifier (MRS) rotation speed 22 is input to the high signal selector 64, compared with the output signal of the constant generator 65, and the higher value is selected and output to the divider 66. The divider 66 divides the mill motor current 21 (a) by the output signal (b) of the high signal selector 64 (a / b).
And outputs the result to the subtractor 68.

On the other hand, the function generator 67 to which the mill coal feed signal 03 is input outputs a reference value based on standard coal to the subtractor 68. The subtractor 68 subtracts the output signal of the divider 66 and the output signal of the function generator 67, and outputs a deviation (deviation) from a reference value.

The output signal (deviation) of the subtracter 68 is squared by the multiplier 69, and the output signal of the multiplier 69 is further multiplied by the output signal k ₁ of the constant generator 70 by the multiplier 71. On the other hand, the multiplier 73 multiplies the output signal (deviation) of the subtractor 68 by the output signal k ₂ of the constant generator 72.

The output signal of the multiplier 73 is supplied to a constant generator 76.
Is added to the output signal k ₃ by the adder 75. The output signal of the adder 75 is the output signal of the multiplier 71 and the adder 74.
After the addition, the output signal of the adder 74 becomes the input signal of the primary delay element 77. And the first-order lag element 7
The output signal 7 is the estimated signal 78 of the coal crushability.

Therefore, according to the present embodiment, the pulverizability of coal can be estimated online even with a plurality of types of coal pulverizers having different properties.

In the first embodiment, the current of the mill motor, the number of revolutions of the rotary classifier (MRS), and the amount of coal supplied are focused on. The correlation between the hydraulic pressure and the roll lift is quite large.
The following embodiment focuses on such a point.

FIG. 2 shows an apparatus for estimating the pulverizability of coal according to a second embodiment of the present invention. The apparatus receives a flow rate of coal supplied to a coal pulverizer, a hydraulic pressure of a mill press, and a roll lift. It is configured to output the pulverizability.
That is, as shown in FIG. 2, the present apparatus inputs the mill pressurizing apparatus oil pressure 01, the roll lift 02, and the mill coal supply amount 03, which are process data, and outputs the estimated coal crushability 16 online.

Hereinafter, the present apparatus will be described in detail with reference to FIG. The signal of the oil pressure 01 of the mill pressurizing device and the roll lift 02
Are multiplied by the multiplier 04. The output signal of the multiplier 04 becomes the input signal of the subtractor 06. On the other hand, the function generator 05 to which the mill coal supply signal 03 is input outputs a reference value based on standard coal to the subtractor 06. Subtractor 06
Subtracts the output signal of the multiplier 04 from the output signal of the function generator 05 that receives the mill coal supply 03 as an input, and outputs a deviation (deviation) from a reference value. The output signal (deviation) of the subtractor 06 is squared by the multiplier 07, and the output signal of the multiplier 07 is further divided by the output signal a ₁ of the constant generator 10 and the multiplier 1
Multiplied by one.

On the other hand, the multiplier 09 multiplies the output signal (deviation) of the subtractor 06 by the output signal a ₂ of the constant generator 08. The output signal of the multiplier 09 is added by the adder 13 to the output signal a ₃ of the constant generator 12. The output signal of the adder 13 is added to the output signal of the multiplier 11 by the adder 14, and then becomes the input signal of the first-order lag element 15. The output signal of the first-order lag element 15 is the estimated signal 16 of the coal crushability.

Therefore, also in the present embodiment, the pulverizability of coal can be estimated online even with a plurality of types of coal pulverizers having different properties.

FIGS. 3 and 4 show an apparatus for estimating the pulverizability of coal according to the third and fourth embodiments of the present invention. The flow rate of coal supplied to the coal pulverizer, the hydraulic pressure of the mill pressurizer, and the roll lift , The mill motor current and the rotational speed of the rotary classifier are input, and the crushability of the coal is output. That is, in these embodiments, the mill pressure oil pressure 01, the roll lift 02, the mill coal supply amount 03, the mill motor current 21, and the rotation classifier rotation speed 22, which are the process data, are input,
The estimated values 41 and 63 of the coal pulverizability are output online.

Hereinafter, the third embodiment will be described in detail with reference to FIG. The signal of the oil pressure 01 of the mill pressurizing device is input to the subtractor 24 together with the output signal of the function generator 23 which receives the mill coal supply 03 as input and outputs a reference value based on standard coal, and subtracts it. The multiplier 32 multiplies the output signal (deviation) of the subtractor 24 by the output signal b ₁ of the constant generator 31. The signal of the roll lift 02 is input to the subtractor 26 together with the output signal of the function generator 25 that receives the mill feed amount 03 as input and outputs a reference value based on standard coal, and is subtracted.

The multiplier 34 outputs the output signal of the subtractor 26 (the
Difference) and the output signal b of the constant generator 33 _TwoMultiply by mill
The signal of the motor current 21 is input with
The output signal of the function generator 27 which outputs the reference value by the semi-coal
The signal is input to the subtractor 28 together with the signal, and is subtracted. Multiplier
36 is an output signal (deviation) of the subtractor 28 and the constant generator 3
5 output signal b _ThreeMultiply by Rotation classifier rotation speed 22
The signal is the standard value of standard coal with the input of mill coal supply 03
And an output signal of a function generator 29 that outputs
30 and subtracted. The multiplier 38 includes the subtractor 3
Output signal (deviation) of 0 and output signal b of constant generator 37_Four
Multiply by Output signals of multipliers 32, 34, 36, 38
Is, after being added by the adder 39, a first-order lag element 40
Input signal. And the output signal of the primary delay element 40
Is the estimated signal 41 of the coal pulverizability.

Therefore, also in this embodiment, the pulverizability of coal can be estimated on-line even with a plurality of types of pulverizers having different properties.

Next, a fourth embodiment will be described in detail with reference to FIG. The signal of the oil pressure 01 of the mill pressurizing device is multiplied by the multiplier 52 with the output signal c ₁ of the constant generator 51. The signal of the roll lift 02 is the output signal c of the constant generator 53.
₂ is multiplied by the multiplier 54. The signal of the mill motor current 21 is multiplied by the multiplier 56 with the output signal c ₃ of the constant generator 55. The signal of the rotation classifier rotation speed 22 is multiplied by the multiplier 58 with the output signal c ₄ of the constant generator 57. The signal of the mill coal supply 03 is multiplied by the multiplier 60 with the output signal c ₅ of the constant generator 59.

The respective multipliers 52, 54, 56, 5
After the output signals of 8 and 60 are added by the adder 61, they become the input signal of the first-order lag element 62. The output signal of the primary delay element 62 is the estimated signal 63 of the coal crushability.
Therefore, also in the present embodiment, the pulverizability of coal can be estimated online even with a plurality of types of pulverizers of coal having different properties.

[0041]

As described above, according to the present invention, it is possible to easily estimate the pulverizability of coal on a multi-coal type having different properties on-line. And the number of coal crushers can be controlled accurately. Also, the prediction of the amount of pulverized coal supplied from the coal crusher to the burner can be made by using an appropriate model. Further, if the above advantages are utilized in a control device, improvement in controllability and reliability can be expected. And so on.

[Brief description of the drawings]

FIG. 1 is a control block diagram illustrating an apparatus for estimating coal pulverizability according to a first embodiment of the present invention.

FIG. 2 is a control block diagram showing an apparatus for estimating coal pulverizability according to a second embodiment of the present invention.

FIG. 3 is a control block diagram illustrating a device for estimating coal pulverizability according to a third embodiment of the present invention.

FIG. 4 is a control block diagram illustrating an apparatus for estimating the pulverizability of coal according to a fourth embodiment of the present invention.

FIG. 5 is a schematic diagram showing a configuration diagram of a coal crusher to which the present invention is applied.

6A is a graph showing the relationship between the current of the mill motor and the amount of coal supplied, and FIG. 6B is a graph showing the relationship between the number of revolutions of a rotary classifier (MRS) and the amount of coal supplied.

FIG. 7 is a schematic diagram showing a control system of a coal pulverizer according to the related art.

[Explanation of symbols]

01 Hydraulic pressure of the mill pressurizer 02 Roll lift 03 Mill coal feed signal 21 Mill motor current 22 Rotational classifier (MRS) speed 64 High signal selector 08, 10, 12, 31, 33, 35, 37, 51, 5
3, 55, 57, 59, 65, 70, 72, 76 Constant generator 66 Divider 05, 07, 23, 25, 27, 29, 67 Function generator 06, 24, 25, 2628, 30, 68 Subtractor 04, 09, 11, 32, 34, 36, 38, 52, 5
4, 56, 58, 60, 69, 71, 73 Multiplier 13, 14, 39, 74, 75 Adder 15, 40, 62, 77 Primary delay element 16, 41, 63, 78 Estimated signal of coal grindability

Claims (6)

[Claims] 1. A pulverizer for a plurality of types of coal having different properties, comprising: a coal feed amount, a current of a mill motor, a rotation speed of a rotary classifier (MRS), a hydraulic pressure of a mill pressurizing device, A first-order lag obtained by combining two or more process data selected from each process data of the roll lift and a preset constant to perform a multi-stage calculation and adding a response delay to an output signal of the calculation means. An automatic coal grindability estimating apparatus characterized in that the output of the element is used as a coal grindability estimated value. 2. A pulverizing apparatus for a plurality of types of coal having different properties, wherein the amount of coal supplied, the current of a mill motor, the number of revolutions of a rotary classifier (MRS), the hydraulic pressure of a mill pressurizing apparatus, One or a plurality of process data selected from each of the roll lift process data is output directly or by a predetermined arithmetic processing, and output from a function generator that receives the respective data and the mill coal supply. Subtraction means for calculating a deviation from a reference value, multiplication means for multiplying the deviation by a constant including a coefficient, addition means for adding a constant to an output signal of the multiplication means, and a response to an output signal of the secondary operation means An automatic coal crushability estimating apparatus, comprising: a first-order lag element that takes into account a delay, wherein an output of the first-order lag element is used as an estimated value of coal crushability. 3. The automatic coal crushability estimating apparatus according to claim 2, wherein: a dividing means for obtaining a ratio between a mill motor current of the crushing apparatus and a rotation speed of a rotary classifier; Subtraction means for calculating a deviation from a reference value output from a function generator having a coal supply amount as an input; a value obtained by squaring the deviation and further multiplying a coefficient; a value obtained by multiplying the deviation by a coefficient; And a second-order operation means comprising a multiplier and an adder, and a first-order lag element for adding a response delay to an output signal of the second-order operation means. An automatic coal crushability estimating device characterized by using an estimated value. 4. The automatic coal crushability estimating apparatus according to claim 2, wherein: a multiplying means for multiplying a hydraulic pressure of the mill pressurizing device of the crushing device by a roll lift; Subtraction means for obtaining a deviation from a reference value output from a function generator having an input as an amount, a deviation obtained by squaring the deviation and further multiplying a coefficient, a deviation multiplied by a coefficient, and a constant A secondary operation means including a multiplier and an adder for adding, a first-order delay element for adding a response delay to an output signal of the second-order operation means, and an output of the first-order delay element is estimated as a coal pulverizability estimated value. Automatic crushability estimation device for coal. 5. The automatic coal crushability estimating apparatus according to claim 2, wherein two or more selected from among a mill pressurizing device oil pressure, a roll lift, a mill motor current, and a rotation classifier rotation speed of the crushing device. A plurality of subtraction means for obtaining a deviation between the process data and a reference value output from a function generator having the process data and the amount of mill coal supplied as inputs; multiplying the deviation of each of the plurality of subtraction means by a constant. Multiplying means of a number corresponding to the subtracting means, adding means for adding signals of the plurality of multiplying means, and a first-order lag element for adding a response delay to an output signal of the adding means 39, An automatic coal grindability estimating apparatus characterized in that an output of a delay element is used as a coal grindability estimated value. 6. The apparatus for automatically estimating coal pulverizability according to claim 1, wherein the mill pressurizing device hydraulic pressure, roll lift, mill motor current, rotation classifier rotation speed, and mill coal feed amount of the pulverizing device are respectively included in the process data. A plurality of multiplying means for multiplying a constant; an adding means for adding a signal of each of the plurality of multiplying means; a first-order lag element for adding a response delay to an output signal of the adding means; An automatic coal crushability estimating device, wherein is an estimated value of coal crushability.